Method for producing solid titanium catalyst component and method for producing olefin polymer

Abstract

To provide a method for producing a solid titanium catalyst component capable of stably producing propylene-based block copolymer particles excellent in particle fluidity.SOLUTION: The method for producing a solid titanium catalyst component includes a contact step of contacting (a) an alkoxymagnesium compound having a pore volume of 200 to 1200 mm3 / g with (b) a halogen-containing titanium compound three or more times, and satisfies the relationship of the following formula (α). (T3)≥(T2)+5 (α) (where (T2) is the temperature in degrees Celsius during the second contact step, and (T3) is the temperature in degrees Celsius during any contact step from the third step onward.)SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a method for producing a solid titanium catalyst component and a method for producing an olefin polymer such as a propylene-based block copolymer. [Background technology]

[0002] Propylene-based resins are used in a variety of fields, including daily necessities, kitchen utensils, packaging films, home appliances, machine parts, electrical parts, and automobile parts.

[0003] Depending on the application, propylene-based block copolymers may be used, which are obtained by the so-called block copolymerization method, in which propylene-based polymers are produced using an olefin polymerization catalyst and then one or more of rubber components, amorphous or low-crystalline ethylene-propylene copolymers (EPRs), and amorphous ethylene-α-olefin copolymers are produced. Propylene-based block copolymers exhibit excellent properties, including high heat resistance (e.g., a high melting point) and impact resistance.

[0004] Generally, it is considered preferable that the flexible copolymer component such as the rubber component has a relatively high molecular weight, in order to provide functions such as impact resistance. Furthermore, the olefin polymerization catalyst for producing the above-mentioned propylene-based block copolymer is often an olefin polymerization catalyst containing a so-called large particle size solid titanium catalyst component obtained by reacting a magnesium compound such as an alkoxymagnesium having a relatively large particle size with a titanium compound such as titanium tetrachloride.

[0005] It is obvious that the higher the content of the rubber component in a propylene-based block copolymer, the higher the impact resistance. However, the rubber component tends to bleed out, which can reduce particle flowability. Many production methods have been disclosed to solve this problem (for example, Patent Documents 1 to 4).

[0006] The present applicant has also disclosed that a propylene-based block copolymer with excellent particle flowability can be obtained even with a high rubber content by using a solid titanium catalyst component that uses a porous magnesium compound that meets specific requirements (Patent Document 5).

[0007] On the other hand, propylene-based block copolymers are also known to be used as raw materials for high-performance propylene polymer compounds used, for example, as main raw materials for various injection-molded articles and for automotive exterior and interior materials. In recent years, there has been a trend toward demands for high performance in a variety of physical properties for these propylene polymer compounds. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] Japanese Patent Application Publication No. 2017-132870 [Patent Document 2] Japanese Patent Application Laid-Open No. 2002-356507 [Patent Document 3] International Publication No. 2018 / 066535 [Patent Document 4] International Publication No. 2022 / 091867 [Patent Document 5] International Publication No. 2019 / 172350 Summary of the Invention [Problem to be solved by the invention]

[0009] In recent years, there has been a trend toward a demand for olefin polymerization catalysts that can give propylene-based block copolymers with higher olefin copolymer contents, such as rubber components, which is understood to be a demand from the viewpoint of further improving impact resistance. As described above, it is known that an olefin polymerization catalyst containing a porous solid titanium catalyst component is suitable for producing a block copolymer having excellent particle flowability while increasing the content of a rubber component, such as an olefin copolymer.

[0010] On the other hand, due to their structure, porous solid components tend to be easily brittle, and it is easy to predict that particle destruction will occur during the preparation process of the solid titanium catalyst component, making it easy to produce fine powder as a by-product. The fine powder is likely to cause problems during the olefin polymer production process, such as clogging of pipes and accumulation (fouling) on ​​the inner walls of reactors, etc. Therefore, a method for more easily producing a solid titanium catalyst component with excellent porosity is desired.

[0011] Therefore, the present invention has been made with an object of providing a method for producing a solid titanium catalyst component that can stably produce propylene-based block copolymer particles having excellent particle flowability, and a method for producing an olefin polymer by polymerizing an olefin in the presence of an olefin polymerization catalyst containing the solid titanium catalyst component, in other words, a porous solid titanium catalyst component. [Means for solving the problem]

[0012] The present inventors have conducted research and found that, when a solid titanium catalyst component is produced by contacting a conventional porous magnesium compound with a titanium-containing compound and, if necessary, an electron donor, by selecting a specific method and temperature conditions, a solid titanium catalyst component having a higher pore volume than conventional ones can be produced, and have thus completed the present invention. That is, the present invention can be characterized by the following requirements:

[0013] [1] (a) Pore volume is 200 to 1200 mm 3 / g of an alkoxymagnesium compound is contacted with (b) a halogen-containing titanium compound three or more times; A method for producing a solid titanium catalyst component, which satisfies the relationship of the following formula (α): (T3)≧(T2)+5 (α) (wherein (T2) is the temperature in degrees Celsius in the second contact step, and (T3) is the temperature in degrees Celsius in any contact step from the third time onwards.)

[0014] [2] The method for producing a solid titanium catalyst component according to [1] above, wherein the temperature (T1) in the first contact step and the temperature (T2) in the first contact step satisfy the relationship of the following formula (β): (T2)≧(T1)-30 (β)

[0015] [3] The method for producing a solid titanium catalyst component according to [1] or [2] above, wherein (T3) is 120°C or higher.

[0016] [4] The method for producing a solid titanium catalyst component according to any one of [1] to [3] above, wherein the alkoxymagnesium compound (a), the halogen-containing titanium compound (b), and further (c) an electron donor are contacted with each other in at least one of the contact steps.

[0017] [5] A solid titanium catalyst component (A) is produced by any one of the methods [1] to [4] above, A method for producing an olefin polymer, comprising polymerizing an olefin in the presence of the solid titanium catalyst component (A) and an organometallic compound (B). [Effects of the Invention]

[0018] According to the present invention, by selecting specific high and low temperature conditions, a solid titanium catalyst component having a high pore volume can be produced. This method makes it possible to produce a solid titanium catalyst component having a high pore volume without increasing the pore volume of the porous magnesium compound used as the raw material more than necessary. [Brief explanation of the drawings]

[0019] [Figure 1] 1 is a graph showing the pore volume distribution of the solid titanium catalyst component of Example 1. [Figure 2] 2 is a graph showing the pore volume distribution of the solid titanium catalyst component of Comparative Example 1. DETAILED DESCRIPTION OF THE INVENTION

[0020] The method for producing a solid titanium catalyst component according to the present invention comprises the steps of: Pore ​​volume is 200 to 1200 mm 3 The method for producing a solid titanium catalyst includes three or more contact steps in which an alkoxymagnesium compound (a) of 1 / g is contacted with a halogen-containing titanium compound (b) and an electron donor (c), preferably a phthalic acid diester, and the conditions in the second contact step (hereinafter also referred to as the "second step") and any third or subsequent contact step (hereinafter also referred to as the "third step or subsequent steps") satisfy the following relationship (α): (T3)≧(T2)+5 (α) (however, (T3): Temperature in degrees Celsius at any step after the third step (T2): Temperature in degrees Celsius in the second step) The second step of the present invention refers to a step of contacting the solid component obtained in the first contact step (hereinafter also referred to as "first step") with a halogen-containing titanium compound (b), and the third step of the present invention refers to a step of contacting the solid component obtained in the second step with a halogen-containing titanium compound (b).

[0021] The contact method between the alkoxy magnesium compound (a) and the halogen-containing titanium compound (b) can basically be any conventionally known method without any limitations. Note that each of the contact steps is, for example, a reaction step in a suspension state, accompanied by a step such as solid-liquid separation, and is specified in accordance with the conventionally known concept that each contact step is separated by a stage at which the composition of each raw material component changes.

[0022] The temperature difference between (T3) and (T2) is preferably 8°C or more, more preferably 10°C or more, and even more preferably 12°C or more. While the upper limit of the temperature difference is not particularly limited, it is preferably 100°C, more preferably 80°C, even more preferably 70°C, and particularly preferably 60°C. When the temperature difference between (T3) and (T2) satisfies the above-mentioned requirement, a solid titanium catalyst component with a high pore volume value is easily obtained. If the temperature difference is too small, the effect of improving the pore volume value may be insufficient.

[0023] It is known that the contact step (reaction step) in the production of a solid titanium catalyst component as in the present invention is divided into three or more steps. However, the present inventors have found that when a solid titanium catalyst component is produced through three or more contact steps (reaction steps) using a magnesium compound (a) having a specific pore volume as described below, the pore volume of the resulting solid titanium catalyst component can be further increased if the temperatures in the second step and the third and subsequent steps satisfy the specific requirements described above.

[0024] The reason why the pore volume value of the solid titanium catalyst component increases when the solid titanium catalyst is produced under conditions that satisfy the above requirements is currently unknown, but the present inventors speculate as follows.

[0025] In the present invention, from the third step onward, the effect of removing the excess or unnecessary halogen-containing titanium compound (b) and the electron donor (c) is likely to take priority over the reaction between the alkoxy magnesium compound (a) and the halogen-containing titanium compound (b). Such removal effect may increase the pore volume.

[0026] Independently, by setting relatively high temperature conditions in the third and subsequent steps, we believe that the walls that form some of the pores (which have relatively weak, thin, or distorted structures) are destroyed or dissolved, creating larger pores, which results in an increase in pore volume. This phenomenon is likely to occur more easily in relatively small pores.

[0027] When the pore volume distribution of the solid titanium catalyst component produced by the method of the present invention is examined, it is found that the number of relatively small pores (for example, pore diameters in the range of 0.01 to 0.05 μm) increases compared to the pore volume distribution obtained by conventional methods. Furthermore, even when the solid titanium catalyst component obtained by the method of the present invention is used to polymerize propylene or the like, an increase in fine powder is hardly observed.

[0028] These results can be considered to be one of the results that support the reason for the increase in the pore volume value. On the other hand, if the reaction steps are set under high temperature conditions up to the second step, the reaction between the alkoxy magnesium compound (a) and the halogen-containing titanium compound (b) is relatively active, which may enable the pore volume to be increased, but may involve the risk of particle collapse, etc.

[0029] The following requirement (β) is a preferable requirement for producing a solid titanium catalyst component according to the present invention. (T2)≧(T1)-30 (β) ((T1): temperature in degrees Celsius in the first contact step (hereinafter also referred to as "first step"))

[0030] The temperatures at each of the above stages do not need to be constant. They can be changed in stages. The above (T1), (T2), and (T3) refer to the temperatures maintained for the longest time in each contact step, and the time is preferably maintained for 15 minutes or more, more preferably 20 minutes or more, and even more preferably 25 minutes or more. If there are multiple temperatures maintained for the same time, the temperature at which the temperature is maintained is the highest temperature among those temperatures.

[0031] The value of (T1)-(T2) is more preferably 25°C or less, even more preferably 15°C or less, particularly preferably 10°C or less, and especially preferably 5°C or less. The value of (T1)-(T2) may be a negative value. The lower limit of the value of (T1)-(T2) is more preferably -30°C, even more preferably -20°C, particularly preferably -15°C, and especially preferably -10°C.

[0032] The first step is primarily a step in which the alkoxymagnesium compound (a) reacts with the halogen-containing titanium compound (b), and the second step can be considered a step for controlling the composition appropriately by removing a portion of the halogen-containing titanium compound (b) or the electron donor (c) when used in excess, in addition to the reaction between the alkoxymagnesium compound (a) and the halogen-containing titanium compound (b). In either case, since relatively large changes are expected, it is generally best not to raise the temperature too high. Specifically, the temperature is 125°C or lower, and more preferably 120°C or lower.

[0033] The components used in the method for producing a solid titanium catalyst component of the present invention will be explained below in order.

[0034] [Production of solid titanium catalyst component] The solid titanium catalyst component has a pore volume of 200 to 1200 mm 3 / g of an alkoxymagnesium compound (a) is contacted with a halogen-containing titanium compound (b) such as a liquid halogen-containing titanium compound, and preferably with an electron donor (c) such as a phthalic acid diester.

[0035] (Alkoxymagnesium compound (a)) The alkoxy magnesium compound (a) used in the present invention is selected from those compounds that satisfy the pore volume requirement (200 to 1200 mm 3 As long as the above-mentioned alkoxymagnesium content (g / g) is satisfied, any known alkoxymagnesium compound used in the production of a solid titanium catalyst component can be used without limitation. For example, the magnesium compounds having an alkoxy group disclosed in the above-mentioned Patent Documents 2 to 4 can be exemplified. As such a magnesium compound having an alkoxy group, dialkoxymagnesium is preferred.

[0036] The alkoxy magnesium compounds may be used alone or in combination of two or more.

[0037] The dialkoxy magnesium may be at least one selected from diethoxy magnesium, dipropoxy magnesium, dibutoxy magnesium, dipentoxy magnesium, diisooctoxy magnesium, ethoxybutoxy magnesium, ethoxyisooctoxy magnesium, and the like, with diethoxy magnesium being preferred.

[0038] The preferred lower limit of the pore volume of these alkoxy magnesium compounds (a) is 250 mm 3 / g, more preferably 300mm 3 / g, more preferably 350 mm 3 On the other hand, the preferred upper limit is 1100 mm 3 / g, more preferably 1000mm 3 / g, more preferably 900mm 3 / g, particularly preferably 850 mm 3 / g.

[0039] The pore volume and pore distribution of the alkoxy magnesium compound (a) can be measured by mercury intrusion porosimetry using, for example, a mercury intrusion porosimeter.

[0040] The alkoxymagnesium compound (a) can be obtained, for example, by contacting and reacting metallic magnesium with a corresponding alcohol and iodine under specific conditions. Depending on the requirements of the conditions, alkoxymagnesium compound (a) having various pore shapes can be produced.

[0041] The secondary particles of the alkoxy magnesium compound (a) are in the form of granules or powder in a dry state, and are usually spherical in shape, but do not necessarily have to be perfectly spherical and may be ellipsoidal.

[0042] Specifically, the alkoxy magnesium compound (a) preferably has a ratio (l / w) of the major axis diameter l to the minor axis diameter w of the secondary particles of 3 or less, more preferably 1 to 2, and even more preferably 1 to 1.5.

[0043] In the method for producing an olefin polymerization catalyst, the alkoxymagnesium compound (a) may contain an alcohol therein. For example, the alkoxymagnesium compound (a) preferably contains 0.1 to 1.5 parts by mass of alcohol, more preferably 0.2 to 1.2 parts by mass of alcohol, and even more preferably 0.4 to 1.0 part by mass of alcohol per 100 parts by mass of the alkoxymagnesium compound (a).

[0044] In the above-mentioned method for producing an olefin polymerization catalyst, the alkoxymagnesium compound (a) preferably has a bulk density of 0.1 to 0.6 g / ml, more preferably 0.2 to 0.5 g / ml, and even more preferably 0.25 to 0.40 g / ml.

[0045] The alkoxy magnesium compound (a) is a component that generally functions as a carrier for the solid titanium catalyst component, and is considered to have a significant effect on the shape of the solid titanium catalyst component and the shape of the resulting propylene-based block copolymer.

[0046] (Halogen-containing titanium compounds (b)) The halogen-containing titanium compound (b) used in the present invention is contacted with the alkoxymagnesium compound (a) to produce the solid titanium catalyst component. Any known halogen-containing titanium compound that has been used to form a solid titanium catalyst component can be used as the halogen-containing titanium compound (b) without any restrictions. More specifically, a compound represented by the following formula (IV) can be given as a preferred example of the halogen-containing titanium compound (b):

[0047] The halogen-containing titanium compounds may be used alone or in combination of two or more. Ti(OR) g X 4-g (IV) (In formula (IV), R is a hydrocarbon group, X is a halogen atom, and g is an integer satisfying 0≦g≦3.)

[0048] Examples of R in formula (IV) include a methyl group, an ethyl group, a propyl group, and a butyl group.

[0049] Examples of titanium compounds represented by formula (IV) include titanium tetrahalides such as TiCl and TiBr; alkoxytitanium trihalides such as Ti(OCH)Cl, Ti(OCH)Cl, Ti(On-C4H)Cl, Ti(OCH)Br, and Ti(O-isoC4H)Br; alkoxytitanium dihalides such as Ti(OCH)Cl and Ti(OCH)Cl; alkoxytitanium monohalides such as Ti(OCH)Cl, Ti(On-C4H)Cl, and Ti(OCH)Br; and tetraalkoxytitanium tetrahalides such as Ti(OCH), Ti(OCH), Ti(OCH) and Ti(O-2-ethylhexyl). Of these, titanium tetrahalides are preferred, with titanium tetrachloride (TiCl) being more preferred. In addition, the above titanium compounds include compounds that do not contain halogen, but they are compounds that can be easily converted into titanium halide compounds by using them in combination with halogen-containing compounds or halogen-containing silicon compounds, so they are included in the examples.Of course, halogen-containing titanium compounds that do not require the above conversion are preferred.

[0050] It is believed that such a halogen-containing titanium compound (b) causes an exchange reaction between the alkoxy group of the alkoxymagnesium compound (a) and the halogen, converting a part of the alkoxymagnesium compound (a) into magnesium halide.

[0051] (Electron donor (c)) As the electron donor (c), any known electron donor disclosed for use in a solid titanium catalyst component can be used without limitation. Among them, phthalic acid diesters are preferred. R' in the ester group (-COOR') is preferably a hydrocarbon group having 3 to 20 carbon atoms. Multiple types of esters may be used in combination.

[0052] The phthalic acid diesters may be used alone or in combination of two or more. Specific examples of the phthalic acid diester include di-n-propyl phthalate, diisopropyl phthalate, di-n-butyl phthalate, diisobutyl phthalate, di-n-hexyl phthalate, diisohexyl phthalate, diheptyl phthalate, dioctyl phthalate, didecyl phthalate, didodecyl phthalate, ditetradecyl phthalate, dihexadecyl phthalate, dioctadecyl phthalate, dieicosyl phthalate, diphenyl phthalate, and dibenzyl phthalate.

[0053] Among the above-mentioned phthalic acid diesters, R' in the ester group (-COOR') is preferably a linear aliphatic hydrocarbon group, particularly a hydrocarbon group having 3 to 6 carbon atoms. The most preferred phthalic acid diester is di-n-butyl phthalate.

[0054] Examples of electron donors other than the phthalic acid diesters include aromatic carboxylic acid esters other than phthalic acid diesters, alicyclic carboxylic acid esters, and polyether compounds.

[0055] For example, alicyclic polycarboxylic acid esters represented by formula (V), alicyclic polyhydric alcohol esters represented by formula (VI), and polyether compounds are preferred. R d (COOR e ) p ···(V) R d (OCOR e ) p (VI)

[0056] R d (COOR e ) p The compound represented by the formula (R d (COOH) p ) to alcohol (R e It can be obtained by reacting R d (OCOR e ) p The compound represented by the formula (R d (OH) p ) to carboxylic acid (R e COOH) to obtain In formula (V) and formula (VI), R d is an alicyclic hydrocarbon group having 5 to 20 carbon atoms, and R e is a hydrocarbon group having 6 to 15 carbon atoms, and p is an integer of 2 or 3.

[0057] Examples of the alicyclic polycarboxylic acid ester represented by formula (V) include dioctyl 3,6-dimethylcyclohexane-1,2-dicarboxylate, didecyl 3,6-dimethylcyclohexane-1,2-dicarboxylate, dioctyl 3-methyl-6-ethylcyclohexane-1,2-dicarboxylate, didecyl 3-methyl-6-ethylcyclohexane-1,2-dicarboxylate, dioctyl 3-methyl-6-n-propylcyclohexane-1,2-dicarboxylate, didecyl 3-methyl-6-n-propylcyclohexane-1,2-dicarboxylate, and 3,6-diethylcyclohexane-1,2-dicarboxylate. These include alicyclic polycarboxylic acid esters in which the cyclic skeleton is substituted with a hydrocarbon group or the like, such as dioctyl and 3,6-diethylcyclohexane-1,2-dicarboxylate, as well as alicyclic polycarboxylic acid esters in which the cyclic skeleton has no substituents other than carboxylic acid esters, such as di-n-hexyl cyclohexane-1,2-dicarboxylate, diheptyl cyclohexane-1,2-dicarboxylate, dioctyl cyclohexane-1,2-dicarboxylate, didecyl cyclohexane-1,2-dicarboxylate, and didodecyl cyclohexane-1,2-dicarboxylate.

[0058] Examples of the alicyclic polyhydric alcohol ester represented by formula (VI) include cyclohexyl-1,2-dihexanoate, cyclohexyl-1,2-dioctanoate, cyclohexyl-1,2-didecanoate, cyclohexyl-1,2-didodecanoate, cyclohexyl-1,2-diheptanoate, 3,6-dimethylcyclohexyl-1,2-dioctanate, 3,6-dimethylcyclohexyl-1,2-decenate, 3,6-dimethylcyclohexyl-1,2-dodecenate, 3-methyl-6-propylcyclohexyl-1,2-dioctanate, 3-methyl-6-propylcyclohexyl-1,2-didecenate, and 3-methyl-6-propylcyclohexyl-1,2-didodecenate.

[0059] The polyether compound is a compound having two or more ether bonds arranged on both sides via a plurality of carbon atoms. Examples of the polyether compound include 1,3-diethers such as 2-isopropyl-2-isobutyl-1,3-dimethoxypropane, 2,2-diisobutyl-1,3-dimethoxypropane, 2-isopropyl-2-isopentyl-1,3-dimethoxypropane, 2,2-dicyclohexyl-1,3-dimethoxypropane, and 2,2-bis(cyclohexylmethyl)1,3-dimethoxypropane.

[0060] (Polar compounds with dipole moments between 0.50 and 4.00 Debye) In the contacting step of the method for producing a solid titanium catalyst component of the present invention, the alkoxy magnesium compound (a), the halogen-containing titanium compound (b), any of the electron donors (c), and other compounds may be contacted. Among such compounds, preferred examples are polar compounds having a dipole moment of 0.50 to 4.00 Debye (hereinafter sometimes simply referred to as "polar compounds"). As such polar compounds, any known compounds that have been used in the production of known solid titanium catalyst components can be used without limitation.

[0061] The polar compounds may be used alone or in combination of two or more. Specific examples of the polar compounds include halogen-containing aromatic hydrocarbons such as chlorobenzene, o-dichlorobenzene, m-dichlorobenzene, trichlorobenzene, α,α,α-trichlorotoluene, o-chlorotoluene, 2,4-dichlorotoluene, benzyl chloride, and 2-chlorobenzyl chloride; halogen-containing aliphatic hydrocarbons such as 1,2-dichloroethane, 1,1,2,2-tetrachloroethane, 1-chloropropane, 2-chloropropane, 1,2-dichloropropane, 1-chlorobutane, 2-chlorobutane, 1-chloro-2-methylpropane, 2-chloro-2-methylpropane, and 1-chloropentane; and halogen-containing silicon compounds such as diphenyldichlorosilane and methyltrichlorosilane. Among these, halogen-containing aromatic hydrocarbons are preferred. More preferred examples include o-dichlorobenzene and 2,4-dichlorotoluene.

[0062] In addition to these, examples of compounds having a dipole moment outside the above range include aromatic hydrocarbon compounds such as toluene and xylene. In the present invention, when propylene is polymerized in the presence of a specific solid titanium catalyst component produced using this polar compound, the by-production of components with a high content of ethylene-derived structural units may tend to be reduced. The inventors believe that this performance is due to the fact that this polar compound strongly interacts with active species, particularly those with a strong electron-deficiency, i.e., high acidity, among the multiple titanium-based polymerization active species that may be present, thereby abstracting the titanium that forms the active species, or interacting with the alkoxymagnesium-based support surface where the exchange reaction with halogen proceeds excessively and the ethylene polymerization activity is increased, thereby reducing the polymerization reaction activity, thereby removing, deactivating, or suppressing active species that may be particularly susceptible to ethylene reaction. It is also speculated that the alkoxymagnesium-based support surface, which is relatively electron-deficient, may be the site where the halogen becomes relatively excessive due to the halogen exchange reaction with the halogen-containing titanium compound (b).

[0063] (Method of producing a solid titanium catalyst component) In the method for producing a solid titanium catalyst component of the present invention, the alkoxymagnesium compound (a), the halogen-containing titanium compound (b), and preferably the electron donor (c) are used, and any known method for producing a solid titanium catalyst component can be used without any restrictions, as long as the above-mentioned relationship (α) is satisfied.

[0064] A preferred example of producing a solid titanium catalyst component will be described below. The alkoxymagnesium compound (a) and an electron donor (c), such as a phthalate diester, are suspended in an aromatic hydrocarbon medium, such as toluene, under an inert gas atmosphere. A liquid halogen-containing titanium compound (b) is then added at a relatively low temperature, such as 0°C to room temperature. The temperature is raised to around 100°C, and the reaction is continued. The liquid phase is then removed by decantation or other methods, and the liquid halogen-containing titanium compound (b) is added again and resuspended. This liquid phase removal and reaction with the liquid halogen-containing titanium compound (b) can be repeated multiple times. A polar compound with a dipole moment of 0.50 to 4.00 Debye can also be used more than once in this process. This "removal and resuspension step" is preferably carried out at a temperature between 80 and 120°C, for example, to remove excess halogen-containing titanium compound (b) and electron donor (c), such as a phthalate diester, and to form stable polymerization active species. In this "removal and resuspension step", an aromatic hydrocarbon medium such as toluene may be used in combination, or washing with an aromatic hydrocarbon medium such as toluene may be carried out after removal of the liquid phase.

[0065] The contact of the above-mentioned components in the first and second steps is usually carried out at temperatures of −70° C. to +125° C., preferably −50° C. to +120° C., and more preferably −30° C. to +120° C. The amounts of the components used in preparing the solid titanium catalyst component vary depending on the preparation method and cannot be generally defined. For example, when an electron donor (c) is used, it can be used in an amount of 0.01 to 10 mol, preferably 0.1 to 5 mol, and the halogen-containing titanium compound (b) can be used in an amount of 0.01 to 1000 mol, preferably 0.1 to 200 mol, per 1 mol of the alkoxymagnesium compound (a).

[0066] When the polar compound is used, the polar compound is usually used in an amount of 1 to 10,000 ml, preferably 5 to 5,000 ml, and more preferably 10 to 1,000 ml per gram of the solid titanium catalyst component to be produced.

[0067] When the halogen-containing titanium compound (b) is used in combination with a polar compound, the polar compound is usually used in an amount of 0.1 to 50 ml, preferably 0.2 to 20 ml, and particularly preferably 0.3 to 10 ml per 100 ml of the halogen-containing titanium compound (b).

[0068] The electron donor (c) such as a phthalic acid diester is used in an amount of usually 0.01 to 10 ml, preferably 0.02 to 5 ml, and particularly preferably 0.03 to 3 ml, per 100 ml of the polar compound.

[0069] The above method can also be carried out by other known methods such as the following (P-1) to (P-3). (P-1) A slurry of an alkoxy magnesium compound (a) in an inert hydrocarbon solvent is contacted with a liquid halogen-containing titanium compound (b) and an electron donor (c) such as a phthalic acid diester, and then the resulting mixture is contacted with the polar compound. (P-2) A slurry of the alkoxy magnesium compound (a), a halogen-containing titanium compound (b), and preferably one or more of the above-mentioned electron donors (c) such as phthalic acid diesters are contacted in multiple batches, and the polar compound is introduced at any stage. (P-3) A slurry of the alkoxy magnesium compound (a) is contacted with the halogen-containing titanium compound (b) to allow the reaction to proceed, and then an electron donor (c) such as a phthalic acid diester is introduced, and the halogen-containing titanium compound (b) is contacted with the polar compound in multiple batches.

[0070] The magnesium content of this solid titanium catalyst component is preferably 10 to 35 mass%. The lower limit is more preferably 12 mass%, even more preferably 14 mass%, and particularly preferably 15 mass%. On the other hand, the upper limit is more preferably 33 mass%, even more preferably 31 mass%, and particularly preferably 30 mass%.

[0071] The titanium content is preferably 2.5 mass % or less, more preferably 0.1 to 2.2 mass %, even more preferably 0.2 to 2.0 mass %, particularly preferably 0.3 to 1.8 mass %, and most preferably 0.4 to 1.4 mass %.

[0072] The content of the electron donor (c) is preferably 8 to 30% by mass. The electron donor (c) / titanium (mass ratio) is preferably 7 or more, more preferably 7.5 to 35, even more preferably 8 to 30, and particularly preferably 8.5 to 25.

[0073] When the above polar compounds are used, the polar compounds are often hardly detected in the solid titanium catalyst component (A). The alkoxymagnesium compound (a) and the solid titanium catalyst component (A) used in the present invention preferably have an average particle size (measured by the method employed in the examples described below or an equivalent method) of 30 to 70 μm.

[0074] When the production method of the present invention is carried out under conditions that satisfy the above-mentioned requirements, a solid titanium catalyst component with a high pore volume value can be obtained. The range of the pore volume value cannot be generally specified because it is affected by the pore volume of the alkoxy magnesium compound (a) used, but it is preferably 200 to 1000 mm 3A more preferable lower limit is 300 mm / g. 3 / g, more preferably 350 mm 3 / g. A more preferable upper limit is 950 mm 3 / g, more preferably 900mm 3 / g, particularly preferably 850 mm 3 / g, particularly preferably 800 mm 3 / g.

[0075] [Production of propylene-based block copolymer] The method for producing an olefin polymer of the present invention comprises the steps of: A solid titanium catalyst component (A) is produced by the method of the present invention described above, This is a method for producing an olefin polymer, in which olefin polymerization is carried out in the presence of an olefin polymerization catalyst containing the solid titanium catalyst component (A) and an organometallic compound (B), and examples of this olefin polymer include a propylene-based block copolymer.

[0076] The propylene-based block copolymer can be produced through a first polymerization step in which propylene and optionally other α-olefins are polymerized in the presence of an olefin polymerization catalyst containing the solid titanium catalyst component (A) and the organometallic catalyst component (B) to produce a crystalline propylene-based (co)polymer, and a second polymerization step in which ethylene, propylene, and, as necessary, a component containing a polymerizable double bond, such as an olefin having 4 to 20 carbon atoms or a diene, are copolymerized in the presence of the crystalline propylene-based (co)polymer produced in the first polymerization step to produce an olefin rubber component, an amorphous or low-crystalline ethylene-propylene copolymer (EPR), and an amorphous ethylene-α-olefin copolymer.

[0077] The solid titanium catalyst component (A) may be used alone or in combination of two or more kinds, and the organometallic catalyst component (B) may be used alone or in combination of two or more kinds. The first and second polymerization steps may be carried out by any of liquid-phase polymerization methods, including bulk polymerization, solution polymerization, and suspension polymerization, as well as gas-phase polymerization. Either batch or continuous polymerization methods may be employed. Preferably, gas-phase polymerization is used, and continuous polymerization is also preferred.

[0078] The organometallic catalyst component (B) may be an organometallic compound containing at least one element selected from the group consisting of Group 1 elements, Group 2 elements, and Group 13 elements of the periodic table.

[0079] Examples of the organometallic catalyst component (B) include compounds containing a Group 13 element such as organoaluminum compounds, alkylated complexes of Group 1 elements with aluminum, and organometallic compounds containing Group 2 elements.

[0080] Preferred are organoaluminum compounds, specifically trialkylaluminum compounds such as triethylaluminum, tributylaluminum, triisobutylaluminum, trihexylaluminum, and trioctylaluminum, with triethylaluminum being particularly preferred.

[0081] The olefin polymerization catalyst can also be used in combination with an electron donor (C). Examples of the electron donor (C) include organosilicon compounds represented by formula (VII), silane compounds represented by formula (VIII), and compounds represented by formula (IX).

[0082] The electron donor (C) may be used alone or in combination of two or more. R n Si(OR') 4-n (VII) Si(OR a )3(NR b R c ) (VIII) RNSi(OR a )3···(IX)

[0083] In formula (VII), R and R' are hydrocarbon groups, and n is an integer where 0 < n < 4. In formula (VIII), R a is a hydrocarbon group having 1 to 6 carbon atoms, R b is a hydrocarbon group having 1 to 12 carbon atoms or hydrogen, and R c is a hydrocarbon group having 1 to 12 carbon atoms.

[0084] In formula (IX), R a is a hydrocarbon group having 1 to 6 carbon atoms, and RN is a cyclic amino group such as a perhydroquinolino group, a perhydroisoquinolino group, a 1,2,3,4-tetrahydroquinolino group, a 1,2,3,4-tetrahydroisoquinolino group, and an octamethyleneimino group.

[0085] Examples of the organosilicon compound represented by formula (VII) include diisopropyldimethoxysilane, t-butylmethyldimethoxysilane, t-butylmethyldiethoxysilane, t-amylmethyldiethoxysilane, dicyclohexyldimethoxysilane, cyclohexylmethyldimethoxysilane, cyclohexylmethyldiethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, t-butyltriethoxysilane, phenyltriethoxysilane, cyclohexyltrimethoxysilane, cyclopentyltrimethoxysilane, 2-methylcyclopentyltrimethoxysilane, cyclopentyltriethoxysilane, dicyclopentyldimethoxysilane, dicyclopentyldiethoxysilane, tricyclopentylmethoxysilane, dicyclopentylmethylmethoxysilane, dicyclopentylethylmethoxysilane, cyclopentyldimethylethoxysilane, and the like.

[0086] Examples of the silane compound represented by formula (VIII) include dimethylaminotriethoxysilane, diethylaminotrimethoxysilane, diethylaminotri-n-propoxysilane, di-n-propylaminotriethoxysilane, methyl-n-propylaminotriethoxysilane, t-butylaminotriethoxysilane, ethyl-n-propylaminotriethoxysilane, ethyl-iso-propylaminotriethoxysilane, and methylethylaminotriethoxysilane.

[0087] Examples of the compound represented by formula (IX) include (perhydroquinolino)triethoxysilane, (perhydroisoquinolino)triethoxysilane, (1,2,3,4-tetrahydroquinolino)triethoxysilane, (1,2,3,4-tetrahydroisoquinolino)triethoxysilane, and octamethyleneiminotriethoxysilane.

[0088] The temperature at which the solid titanium catalyst component (A) and the organometallic catalyst component (B) are contacted to form the olefin polymerization catalyst is preferably −30° C. or higher and 150° C. or lower, more preferably −25° C. or higher and 130° C. or lower, and even more preferably −25° C. or higher and 120° C. or lower.

[0089] The amount of the solid titanium catalyst component (A) used in the first polymerization step and the second polymerization step can be 0.0001 mmol or more and 0.5 mmol or less, and preferably 0.005 mmol or more and 0.1 mmol or less, in terms of titanium atom per liter of polymerization volume.

[0090] The amount of the organometallic catalyst component (B) used in the first and second polymerization steps can be 1 mole or more and 2000 moles or less, and preferably 5 moles or more and 500 moles or less, per mole of titanium atom in the polymerization system.

[0091] The amount of the electron donor (C) used in the first polymerization step and the second polymerization step can be 0.001 mol or more and 50 mol or less, preferably 0.01 mol or more and 30 mol or less, and more preferably 0.05 mol or more and 20 mol or less, per 1 mol of the organometallic catalyst component (B) in the polymerization system.

[0092] The polymerization temperature in the first polymerization step and the second polymerization step can be 20°C or higher and 200°C or lower, preferably 30°C or higher and 100°C or lower, and more preferably 50°C or higher and 90°C or lower.

[0093] The pressure (gauge pressure) in the first polymerization step and the second polymerization step can be set to normal pressure to 9.8 MPa or less, and is preferably 0.20 MPa or more and 4.9 MPa or less.

[0094] In the first and second polymerization steps, polymerization may be carried out in the presence of hydrogen in order to reduce the molecular weight of the resulting polymer and adjust the melt flow rate (MFR) and the intrinsic viscosity [η] of the Dsol component described below to within desired ranges.

[0095] In the second polymerization step, for example, propylene, which is the raw material for the rubber component, and one or more α-olefins selected from ethylene and α-olefins having 4 to 20 carbon atoms may be polymerized with the crystalline propylene (co)polymer obtained in the first polymerization step. For example, when the rubber component is a propylene-ethylene copolymer rubber, the ethylene / (ethylene+propylene) gas ratio is preferably 5 mol% to 80 mol%, more preferably 10 mol% to 70 mol%, and even more preferably 15 mol% to 60 mol%.

[0096] Note that, prior to the first polymerization step and the second polymerization step, prepolymerization may be carried out at a higher catalyst concentration. The prepolymerization is preferably carried out at a temperature lower than the polymerization temperature, specifically, for example, in the range of 0 to 50°C.

[0097] [Propylene block copolymer] The propylene-based block copolymer can be obtained, for example, by polymerizing an olefin containing ethylene and propylene in the presence of a crystalline propylene-based (co)polymer to produce a rubber component, an amorphous or low-crystalline ethylene-propylene copolymer (EPR), an amorphous ethylene-α-olefin copolymer, or the like.

[0098] The propylene-based block copolymer is usually in the form of powder or pellets, and more preferably in the form of propylene-based block copolymer particles formed during polymerization, which will be described later.

[0099] The propylene-based block copolymer is not particularly limited as long as it is a block copolymer containing structural units derived from propylene. However, from the viewpoints of having a good balance of rigidity, impact resistance, and moldability and being able to easily obtain molded articles with good appearance, it is preferable that the propylene-based block copolymer is a copolymer containing a rubber component, and more preferable that the propylene-based block copolymer is a copolymer having a component soluble in n-decane at 23°C (hereinafter also referred to as the "Dsol component") and a component sparingly soluble in n-decane at 23°C (hereinafter also referred to as the "Dinsol component").

[0100] The Dsol component refers to the component that is dissolved in the n-decane solution after the propylene-based block copolymer is heated and dissolved in n-decane at 150°C for 2 hours and then cooled to 23°C. The other components in the propylene-based block copolymer are Dinsol components.

[0101] The Dsol component may be a component in which the rubber component is the main component, and is preferably a component in which the main component is a copolymer rubber component of propylene and one or more α-olefins selected from ethylene and α-olefins having a carbon number of 4 to 20. More specifically, the amount of rubber component in the Dsol component is preferably more than 50% by mass, and 80% to 100% by mass, and more preferably 90% to 100% by mass.

[0102] Examples of the α-olefins having 4 to 20 carbon atoms include 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene, and 1-eicosene. The α-olefin to be copolymerized is preferably an α-olefin selected from ethylene or an α-olefin having 4 to 10 carbon atoms, and more preferably an α-olefin selected from ethylene, 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 1-octene, and 1-decene.

[0103] The amount of structural units derived from one or more α-olefins selected from ethylene and α-olefins having 4 to 20 carbon atoms contained in the Dsol component is greater than the amount of structural units derived from ethylene or α-olefins having 4 to 20 carbon atoms contained in the crystalline propylene-based (co)polymer component described below or the decane-insoluble component (Dinsol component), and is usually 25 mol % or more of the copolymer rubber.

[0104] In particular, since a Dsol component containing ethylene units tends to have a low glass transition temperature, it is preferable that the Dsol component contains a large amount of ethylene units. The lower limit of the ethylene unit content in the Dsol component is preferably 30 mol%, more preferably 36.0 mol%, and even more preferably 40 mol%, while the upper limit is preferably 70 mol%, more preferably 65 mol%, and even more preferably 60 mol%.

[0105] When the content of ethylene units becomes relatively high, the glass transition temperature of the rubber component decreases and the crystallinity also decreases, so the rubber component becomes flexible and has excellent impact resistance.

[0106] From the viewpoint of easily obtaining a molded article having excellent balance between rigidity and impact resistance, the content of the Dsol component in the propylene-based block copolymer is preferably 5% by mass or more and 50% by mass or less, more preferably 10% by mass or more and 50% by mass or less, even more preferably 25% by mass or more and 50% by mass or less, and particularly preferably 30% by mass or more and 40% by mass or less, relative to 100% by mass of the total of the Dsol component and the Dinsol component.

[0107] As will be described later, the propylene-based block (co)polymer may be used as a composition in combination with an elastomer, an inorganic filler such as talc, etc. In order to easily obtain a molded article having a good appearance and a well-balanced excellent property in impact resistance, high fluidity, and high melt elasticity, the intrinsic viscosity [η] of the Dsol component of such a composition is preferably 1.5 dl / g or more and 10.0 dl / g or less, and more preferably 2.0 dl / g or more and 7.0 dl / g or less.

[0108] The above [η] can be the value of ηsp / C when the concentration (C) is extrapolated to 0 in the equation showing the relationship between concentration and specific viscosity, obtained by dissolving 20 mg of propylene-based block copolymer in 15 ml of decalin, measuring the specific viscosity ηsp in an oil bath at 135°C, diluting the decalin solution by adding 5 ml of decalin solvent, and then measuring the specific viscosity ηsp three more times.

[0109] The Dinsol component is a component mainly composed of a crystalline propylene-based (co)polymer component. More specifically, the amount of the crystalline propylene-based (co)polymer component in the Dinsol component is more than 50% by mass, preferably 80% to 100% by mass, and more preferably 90% to 100% by mass.

[0110] The crystalline propylene (co)polymer component is a crystalline propylene homopolymer or a copolymer of propylene and one or more α-olefins selected from ethylene and α-olefins having a carbon number of 4 to 20. The amount of structural units derived from the α-olefin is preferably 1.5 mol % or less of the crystalline propylene (co)polymer component.

[0111] The content of the Dinsol component in the propylene-based block copolymer is preferably 50% by mass or more and 95% by mass or less, more preferably 50% by mass or more and 90% by mass or less, even more preferably 50% by mass or more and 75% by mass or less, and particularly preferably 60% by mass or more and 70% by mass or less, relative to 100% by mass of the total of the Dsol component and the Dinsol component, from the viewpoint of being able to easily obtain a molded product having an excellent balance of rigidity and impact resistance.

[0112] Examples of the α-olefins having 4 to 20 carbon atoms include 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene, and 1-eicosene. The α-olefin to be copolymerized is preferably an α-olefin selected from ethylene or an α-olefin having 4 to 10 carbon atoms, and more preferably an α-olefin selected from ethylene, 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 1-octene, and 1-decene.

[0113] The melt flow rate (MFR) of the propylene-based block copolymer, measured at 230°C under a load of 2.16 kg according to a method in accordance with ASTM D1238, can be 5 g / 10 min or more and 300 g / 10 min or less, and preferably 5 g / 10 min or more and 200 g / 10 min or less.

[0114] Propylene-based block copolymers having an MFR in the above range have excellent fluidity, and therefore can be used to obtain compositions that can be easily injection-molded. Furthermore, these compositions can be easily used to obtain molded articles that have excellent impact resistance and are suitable for use in automobile parts, etc.

[0115] The content of the propylene-based block copolymer relative to the total mass of the composition is preferably 58% by mass or more and 90% by mass or less, and more preferably 60% by mass or more and 90% by mass or less, from the viewpoint that a molded product having an excellent balance between rigidity and impact resistance can be easily obtained.

[0116] The composition may contain other components such as a resin other than the propylene-based block copolymer, a light stabilizer, a heat stabilizer, a weathering stabilizer, an antioxidant, an antioxidant, a fatty acid metal salt, a softener, a dispersant, a filler, a colorant, a pigment, an antistatic agent, a slip agent, an antiblocking agent, an antifogging agent, a lubricant, a natural oil, a synthetic oil, or a wax.

[0117] The composition can also be used as a compound with a resin other than the propylene-based block copolymer or a rubber component. Suitable polymers for use as the rubber component include known elastomers such as ethylene / propylene copolymer, ethylene / butene copolymer, ethylene / octene copolymer, ethylene / propylene / diene terpolymer, ethylene / butene / diene terpolymer, styrene-based thermoplastic elastomer, butadiene rubber, isoprene rubber, and butyl rubber.

[0118] Examples of the additives such as stabilizers include hindered amines, hindered phenols, and phosphorus-based stabilizers, and examples of the fillers include glass fiber, carbon fiber, talc, and mica.

[0119] The propylene-based block copolymer obtained by the production method according to the present invention can be molded into various molded articles by known molding methods, such as injection molding, (T-die) extrusion molding, inflation molding, blow molding, vacuum molding, stamping molding, rotational molding, and roll molding. Suitable examples of such molded articles include exterior materials (bumpers, back doors, etc.) and interior materials (instrument panel materials, etc.) for automobiles, which can take advantage of the high rigidity, heat resistance, and impact resistance of the molded articles. [Example]

[0120] The present invention will be described in more detail below with reference to examples, but the scope of the present invention is not limited to the descriptions in the examples. The glass reactors used in the following experiments include pressure-resistant reactors such as autoclaves, and were appropriately selected and used depending on the pressure during the reaction.

[0121] [Example 1] (Preparation of solid titanium catalyst component) (1st step) Dry nitrogen was continuously supplied to a 400 mL glass reactor equipped with a gas supply line, a gas vent line, a stirrer, etc. under atmospheric pressure to dry the vessel. Thereafter, the reaction was carried out under a dry nitrogen atmosphere. 3 15 g of titanium dioxide (1 / g) was suspended in 120 mL of paraxylene and the temperature was adjusted to 20°C (the temperature during this procedure may be referred to as the initial temperature) while stirring. While maintaining this suspension at 20°C, 30 mL of titanium tetrachloride was added dropwise over 1 hour. The temperature was then raised to 115°C over 95 minutes and maintained at this temperature for 120 minutes. During this period, 4.0 mL of di-n-butyl phthalate (DNBP) was added at 90°C. Next, the solid portion was collected by hot filtration at 100°C and washed twice with toluene at 90°C (this completes the first step).

[0122] (2nd process) The solid portion was suspended in 120 mL of paraxylene and 30 mL of titanium tetrachloride, collected, and returned to the 400 mL glass reactor, and the temperature was maintained at 115° C. for 120 minutes while stirring. Thereafter, the solid portion was collected by hot filtration at 100°C in the same manner as in the first step, and washed twice with toluene at 90°C (this completes the second step).

[0123] (3rd step) The solid portion was suspended in 150 ml of paraxylene, 7.3 ml of titanium tetrachloride, and 32 ml of decane at room temperature, and the suspension was returned to the 400 ml glass reactor. 1.0 ml of diisobutyl phthalate was added with stirring, and the temperature was then raised to 130°C and maintained at that temperature for 72 minutes. Thereafter, the mixture was hot filtered at 100°C in the same manner as in the first step, and washed successively with decane at 100°C, decane at room temperature, and hexane at room temperature to obtain a solid titanium catalyst component (C-1) in which no free titanium compounds were detected (this completes the third step).

[0124] During the decane washing at room temperature, a portion of the decane slurry of the solid titanium catalyst component (C-1) was collected for polymerization, and the remainder was washed with hexane and then dried to examine the catalyst composition. The results are shown in Table 1.

[0125] (Production of propylene homopolymer) 500 g of propylene and 5.0 nL of hydrogen were added to a 2-liter polymerization reactor equipped with a stirrer at room temperature. Then, 0.3 mmol of triethylaluminum, 0.06 mmol of diethylaminotriethoxysilane, and 0.0024 mmol of the solid titanium catalyst component (C-1) in terms of titanium atoms were added. The polymerization reactor was maintained at 25°C for 10 minutes, then heated to 70°C and maintained at 70°C for 90 minutes. After cooling, unreacted propylene and hydrogen were purged. The resulting polymer particles were then dried under reduced pressure at 80°C overnight to obtain a particulate propylene homopolymer (HP-1).

[0126] (Production of Propylene Block Copolymer Particles) 500 g of propylene and 5.0 nL of hydrogen were added to a 2-liter polymerization reactor equipped with a stirrer at room temperature. Then, 0.5 mmol of triethylaluminum, 0.10 mmol of diethylaminotriethoxysilane, and 0.004 mmol of the solid titanium catalyst component (C-1) (titanium atom equivalent) were added. The polymerization reactor was maintained at 25°C for 10 minutes, then heated to 70°C and held at 70°C for 20 minutes. The temperature was then lowered while purging unreacted propylene and hydrogen. Nitrogen substitution was then repeated several times to thoroughly remove propylene and hydrogen. Next, 0.12 nL of hydrogen was added, and a mixed gas with a gas ratio of ethylene / (ethylene + propylene) = 44 mol% was supplied. Gas-phase polymerization was carried out at a total pressure of 0.4 MPa, and polymerization was continued until the decane-soluble component content (Dsol) reached 28-36%. After the reaction was completed, the reaction was stopped with a small amount of methanol, and unreacted ethylene, propylene, and hydrogen were purged. The resulting polymer particles were then dried under reduced pressure at room temperature overnight to obtain a particulate propylene-based block copolymer (ICP-1). The drop time ratio was measured using this polymer. A portion of the resulting polymer was separately collected and dried overnight at 80°C, and measurements other than the drop time ratio were performed. The polymerization activity, MFR, bulk density (BD), decane-soluble component content (Dsol), intrinsic viscosity [η] of the decane-soluble component, ethylene-derived structural unit content (sometimes referred to as ethylene unit) of the decane-soluble component, and falling time ratio of the obtained propylene-based block copolymer were measured by the following methods. The results are shown in Tables 2 and 3.

[0127] (Method for measuring pore volume) The pore volumes of the diethoxymagnesium and solid titanium catalyst components were measured according to the method described in Patent Document 5. That is, the measurements were performed using a mercury porosimeter (trade name: PoreMaster 60GT, manufactured by Quantachrome). The obtained data was analyzed using analysis software (trade name: Poremaster for Windows) attached to the device, and the cumulative value of pore diameters of 0.003 to 1.0 μm was determined.

[0128] (Method of measuring polymer properties) (1) Melt flow rate (MFR) The melt flow rate (MFR) was measured in accordance with ASTM D1238E standard at a temperature of 230°C and a load of 2.16 kg.

[0129] (2) Bulk density (BD) The bulk density (BD) was measured according to the JIS K-6721 standard.

[0130] (3) Decane soluble component (Dsol) content, ethylene unit content Approximately 3 grams (10 -4 The mass was measured to the nearest gram. This mass was represented as b (grams) in the formula below. ), 500 ml of decane, and a small amount of a heat stabilizer that was soluble in decane and had a boiling point that was substantially distilled off during vacuum drying, as described below, were added. The mixture was heated to 150°C over 2 hours while stirring with a stirrer under a nitrogen atmosphere to dissolve the propylene polymer, and then maintained at 150°C for 2 hours, followed by slow cooling to 23°C over 8 hours. The resulting liquid containing a precipitate of the propylene polymer was filtered under reduced pressure using a 25G-4 standard glass filter manufactured by Tokyo Glass Kikai Co., Ltd. 100 ml of the filtrate was collected and dried under reduced pressure to obtain a decane-soluble component (corresponding to 100 ml of the filtrate). The mass of this component was then adjusted to 10 -4 The mass was measured to the unit of grams (this mass is represented as a (grams) in the formula below). After this operation, the content of the decane-soluble component was determined by the formula below. Decane soluble component content = 100×(500×a) / (100×b)

[0131] The content of ethylene-derived units in the decane-soluble component was measured using the decane-soluble component obtained by the above-mentioned reduced pressure drying. 13 Measurement was performed using C NMR (Bruker Biospin, AVANCE IIIcryo-500 instrument), and the ethylene-derived units and propylene-derived units were identified by the usual method, and the units were identified from their absorption intensity ratio.

[0132] (4) Intrinsic viscosity of decane-soluble components [η] (dl / g) The intrinsic viscosity [η] of the decane-soluble component obtained by method (3) above was measured at 135°C using decalin solvent. Approximately 20 mg of sample was dissolved in 15 ml of decalin, and the specific viscosity ηsp was measured in an oil bath at 135°C. After diluting this decalin solution with 5 ml of decalin solvent, the specific viscosity ηsp was measured in the same manner. This dilution procedure was repeated two more times, and the value of ηsp / C when the concentration (C) was extrapolated to 0 was determined as the intrinsic viscosity.

[0133] (5) Fall time and fall time ratio (%) The falling time was measured using a funnel having the shape disclosed in Figure 1 of Patent Document 5, in accordance with the method described in Patent Document 5. In this case, the heat and load treatment refers to collecting 100 g of propylene-based block copolymer particles within an area of ​​20 cm x 13 cm, placing a square weight with a mass of 10 kg and a base of 17 cm x 11 cm on top of them, and maintaining the mixture at 80°C for 24 hours. Note that it is preferable that the propylene-based block copolymer particles to be subjected to the heat and load treatment are all collected from the particles subjected to the falling time test at room temperature and used as is. The drop time ratio was determined in accordance with the method described in Patent Document 5. That is, as described above, the drop time (X) at room temperature and the drop time (Y) after heat load treatment were measured, and the drop time ratio was calculated using X and Y according to the following formula, and used as an index for evaluating particle fluidity. Fall time ratio (%) = {(Y / X)-1} x 100 The falling seconds ratio is an index that indicates that a smaller value indicates better particle fluidity.

[0134] (Amount of fine powder) Vibration sieve fractionation was carried out in a conventional manner, and the weight ratio of particles passing through a sieve with 180 μm openings was determined.

[0135] [Example 2] (Preparation of solid titanium catalyst component) (1st step) A 400 mL glass reactor equipped with a gas supply line, a gas vent line, and a stirrer was dried by continuously supplying dry nitrogen under atmospheric pressure, and the reaction was then carried out under a dry nitrogen atmosphere. 3 15 g of titanium dioxide (1 / g) was suspended in 120 mL of toluene and the temperature was adjusted to 10°C while stirring. While maintaining this suspension at 10°C, 30 mL of titanium tetrachloride was added dropwise over 1 hour. The temperature was then raised to 115°C over 105 minutes and maintained at that temperature for 60 minutes. During this period, 4.0 mL of di-n-butyl phthalate (DNBP) was added at 90°C. The resulting reaction solution was allowed to stand for 40 minutes while maintained at 115°C, and the supernatant was removed to obtain a slurry-like reaction product. To the above slurry-like reaction product, 150 mL of toluene at 90°C was added, stirred, allowed to stand, and then the supernatant was removed. This process was repeated three times to wash the reaction product, and the temperature was lowered to 30°C while stirring to obtain a reaction product containing a slurry-like solid component (this marks the end of the first step).

[0136] (2nd process) The solid slurry containing 70 mL of washed toluene was suspended in a mixture of 50 mL of toluene and 30 mL of titanium tetrachloride, returned to the 400 mL glass reactor, and maintained at 115°C for 60 minutes while stirring. After that, as in the first step, the solid was left to stand for 40 minutes, and then washed three times with toluene at 90°C. Additionally, the solid was washed three times with toluene at room temperature (this marked the end of the second step).

[0137] (3rd step) The solid slurry obtained in the second step, containing 70 mL of washed toluene, was suspended in 150 mL of toluene and 7.3 mL of titanium tetrachloride, and returned to the 400 mL glass reactor. 1.0 mL of diisobutyl phthalate was added with stirring, and the mixture was heated to 130°C, maintained at this temperature for 12 minutes, and then allowed to stand for 40 minutes. The pressure in the reactor was a pressurized environment of 0.1 MPa-G. The mixture was then hot filtered at 100°C and washed successively with toluene at 90°C, toluene at room temperature, decane at room temperature, and hexane at room temperature to obtain a solid titanium catalyst component (C-2) in which no free titanium compounds were detected (the third step was completed). A portion of the solid titanium catalyst component (C-2) was collected as a decane slurry and used for the polymerization described below, while the remainder was dried to examine the catalyst composition. The results are shown in Table 1.

[0138] (Production of propylene homopolymer) A propylene homopolymer (HP-2) was obtained in the same manner as in Example 1, except that the solid titanium catalyst component (C-2) was used.

[0139] (Production of propylene block copolymer) A propylene-based block polymer (ICP-2) was obtained in the same manner as in Example 1, except that the solid titanium catalyst component (C-2) was used. The results are shown in Tables 1 to 3.

[0140] [Example 3] (Preparation of solid titanium catalyst component) A solid titanium catalyst component (C-3) was obtained in the same manner as in Example 1, except that in the first, second, and third steps, paraxylene was changed to metaxylene, the holding temperature of the suspension during the dropwise addition of titanium tetrachloride in the first step was set to 10°C, and the time required for heating to 115°C was set to 105 minutes.

[0141] (Production of propylene homopolymer) A propylene homopolymer (HP-3) was obtained in the same manner as in Example 1, except that the solid titanium catalyst component (C-3) was used. The results are shown in Tables 1 and 2.

[0142] [Example 4] (Preparation of solid titanium catalyst component) A solid titanium catalyst component (C-4) was obtained in the same manner as in Example 1, except that in the first, second, and third steps, paraxylene was changed to ortho-xylene, the suspension was held at a temperature of 10°C during the dropwise addition of titanium tetrachloride in the first step, and the time required for heating to 115°C was 105 minutes.

[0143] (Production of propylene homopolymer) A propylene homopolymer (HP-4) was obtained in the same manner as in Example 1, except that the solid titanium catalyst component (C-4) was used. The results are shown in Tables 1 and 2.

[0144] [Comparative Example 1] (Preparation of solid titanium catalyst component) In the first, second, and third steps, paraxylene was replaced with toluene, the initial temperature in the first step was 10°C, and the time required to heat up to 115°C was 105 minutes. A solid titanium catalyst component (CC-1) was obtained in the same manner as in Example 1, except that the holding temperature in the third step was 115° C. During the reaction at 115° C., no change in the liquid volume was observed.

[0145] (Production of propylene homopolymer) A propylene homopolymer (CHP-1) was obtained in the same manner as in Example 1, except that the solid titanium catalyst component (CC-1) was used.

[0146] (Production of propylene-based block copolymers) A propylene-based block polymer (CICP-1) was obtained in the same manner as in Example 1, except that the solid titanium catalyst component (CC-1) was used. The results are shown in Tables 1 to 3.

[0147] Comparative Example 2 (Preparation of solid titanium catalyst component) A solid titanium catalyst component (CC-2) was obtained in the same manner as in Example 1, except that in the first, second, and third steps, paraxylene was replaced with toluene, the initial temperature in the first step was changed to 10°C, the time required to raise the temperature to 115°C was changed to 105 minutes, and the holding temperature in the third step was changed to 115°C and the holding time was changed to 192 minutes. No change in the liquid volume was observed during the reaction at 115°C.

[0148] (Production of propylene homopolymer) A propylene homopolymer (CHP-2) was obtained in the same manner as in Example 1, except that the solid titanium catalyst component (CC-2) was used.

[0149] (Production of propylene-based block copolymers) A propylene-based block polymer (CICP-2) was obtained in the same manner as in Example 1, except that the solid titanium catalyst component (CC-2) was used. The results are shown in Tables 1 to 3.

[0150] Comparative Example 3 (Preparation of solid titanium catalyst component) The solid slurry obtained in the same manner as in Example 2, except that the second and third steps were not carried out, was filtered at room temperature and washed successively with toluene at room temperature, decane at room temperature, and hexane at room temperature to obtain a solid titanium catalyst component (CC-3) from which no free titanium compound was detected. No change in the liquid volume was observed during the reaction at 115°C. The results are shown in Table 1.

[0151] Comparative Example 4 (Preparation of solid titanium catalyst component) The solid slurry obtained in the same manner as in Example 2, except that the third step was omitted, was filtered at room temperature and washed successively with toluene at room temperature, decane at room temperature, and hexane at room temperature to obtain a solid titanium catalyst component (CC-4) from which no free titanium compound was detected. No change in the liquid volume was observed during the reaction at 115°C. The results are shown in Table 1.

[0152] [Table 1]

[0153] [Table 2]

[0154] [Table 3]

[0155] The results of the above examples and comparative examples show that the solid titanium catalyst component obtained by the production method of the present invention has a high pore volume value, and the propylene-based block copolymer particles obtained by the production method of the present invention have excellent particle fluidity. These results suggest that the block copolymer particles obtained by the production method of the present invention exhibit good particle fluidity, with particle stickiness and other issues being suppressed, even when subjected to thermal history.

[0156] [Example 5] (Preparation of solid titanium catalyst component) A solid titanium catalyst component (C-5) was obtained by carrying out the same operations as in Example 2, except that in the third step, paraxylene was used instead of toluene under a normal pressure nitrogen environment, the holding temperature was 110°C in the first and second steps, the temperature rise time in the first step was 100 minutes, washing with paraxylene at room temperature was carried out after completion of the second step, and the holding temperature was 125°C in the third step.

[0157] (Production of propylene homopolymer) A propylene homopolymer (HP-5) was obtained in the same manner as in Example 1, except that the solid titanium catalyst component (C-5) was used. The results are shown in Tables 4 and 5.

[0158] [Example 6] (Preparation of solid titanium catalyst component) A solid titanium catalyst component (C-6) was obtained in the same manner as in Example 1, except that the initial temperature in the first step was 10°C, the temperature rise time was 105 minutes, paraxylene was changed to toluene in the first and second steps, 250 ml of paraxylene was used in the third step, decane was not used, and the holding temperature was 130°C. No change in the liquid volume was observed during the reaction at 115°C.

[0159] (Production of propylene homopolymer) A propylene homopolymer (HP-6) was obtained in the same manner as in Example 1, except that the solid titanium catalyst component (C-6) was used. The results are shown in Tables 4 and 5.

[0160] [Example 7] (Preparation of solid titanium catalyst component) A solid titanium catalyst component (C-7) was obtained in the same manner as in Example 1, except that the initial temperature in the first step was 10°C, the temperature rise time was 105 minutes, and toluene was used instead of paraxylene in the first and second steps. No change in the liquid volume was observed during the reaction at 115°C.

[0161] (Production of propylene homopolymer) A propylene homopolymer (HP-7) was obtained in the same manner as in Example 1, except that the solid titanium catalyst component (C-7) was used. The results are shown in Tables 4 and 5.

[0162] [Example 8] (Preparation of solid titanium catalyst component) (1st step) Dry nitrogen was continuously supplied to a 400 mL glass reactor equipped with a gas supply line, a gas vent line, and a stirrer under atmospheric pressure to dry the vessel, and the reaction was then carried out under a dry nitrogen atmosphere. 80 mL of titanium tetrachloride was charged into the reactor, and the temperature was lowered to -24°C with stirring. Next, the diethoxymagnesium (pore volume: 830 mm) suspended in 35 mL of decane was added. 311 g of ethanol (1 / g) was slowly (over 10 minutes) charged into the reactor. The temperature was then raised to -20°C, then raised to 110°C over 205 minutes, and then maintained at that temperature for 120 minutes. During this time, 2.9 mL of di-n-butyl phthalate (DNBP) was added at 90°C. Next, the solid portion was collected by hot filtration at 100°C and washed five times with decane at 100°C (this completes the first step).

[0163] (2nd process) The solid was suspended in a mixed solution of 110 mL of titanium tetrachloride, collected, and returned to the 400 mL glass reactor, and the temperature was maintained at 110° C. for 120 minutes while stirring. Thereafter, in the same manner as in the first step, the solid portion was collected by hot filtration at 100°C and washed three times with decane at 100°C and twice with decane at room temperature (this completes the second step).

[0164] (3rd step) The solid portion was suspended in 110 ml of paraxylene and 5.4 ml of titanium tetrachloride at room temperature, returned to the 400 ml glass reactor, and 0.7 ml of diisobutyl phthalate was added with stirring. The mixture was then heated to 130°C and maintained at that temperature for 72 minutes. Thereafter, in the same manner as in the first step, the mixture was hot filtered at 100°C and washed successively with decane at 100°C, decane at room temperature, and hexane at room temperature to obtain a solid titanium catalyst component (C-8) in which no free titanium compounds were detected (this completes the third step).

[0165] During the decane washing at room temperature, part of the solid titanium catalyst component (C-8) was collected as a decane slurry for polymerization, and the remainder was washed with hexane and then dried to examine the catalyst composition and pore volume. The results are shown in Table 1.

[0166] (Production of propylene homopolymer) A propylene homopolymer (HP-8) was obtained in the same manner as in Example 1, except that the solid titanium catalyst component (C-8) was used. The results are shown in Tables 4 and 5.

[0167] [Table 4]

[0168] [Table 5]

[0169] As described above, the catalysts produced in Examples 5 to 8 have high pore volumes, high propylene homopolymerization activity, and produce propylene homopolymers with high stereoregularity, high bulk density, and little fine powder. Therefore, if a propylene-based block copolymer is produced using the catalysts obtained by the methods of Examples 5 to 8, it is expected that block copolymer particles will be obtained that exhibit good particle fluidity and that will be free from particle stickiness even after thermal history.

Claims

1. (a) Pore volume is 200 to 1200 mm ３ / g of an alkoxymagnesium compound is contacted with (b) a halogen-containing titanium compound three or more times; A method for producing a solid titanium catalyst component, which satisfies the relationship of the following formula (α): (T3)≧(T2)+5 (α) (wherein (T2) is the temperature in degrees Celsius at the second contact step, and (T3) is the temperature in degrees Celsius at any contact step from the third time onwards.)

2. 2. The method for producing a solid titanium catalyst component according to claim 1, wherein the temperature (T1) in the first contact step and the temperature (T2) in the first contact step satisfy the relationship of the following formula (β): (T2)≧(T1)-30 (β)

3. 2. The method for producing a solid titanium catalyst component according to claim 1, wherein the temperature (T3) is 120° C. or higher.

4. 2. The method for producing a solid titanium catalyst component according to claim 1, wherein the alkoxy magnesium compound (a), the halogen-containing titanium compound (b), and (c) an electron donor are contacted with each other in at least one of the contact steps.

5. A solid titanium catalyst component (A) is produced by the method of claim 1, A method for producing an olefin polymer, comprising polymerizing an olefin in the presence of the solid titanium catalyst component (A) and an organometallic compound (B).

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