Method for manufacturing resin compositions, method for manufacturing pellets

Abstract

The objective is to provide a method for producing a resin composition, a method for producing pellets, and a resin composition that can yield a molded article with relatively excellent surface impact strength. [Solution] The present invention relates to a method for producing a resin composition, comprising a melt-kneading step of melt-kneading raw materials for a resin composition, and a filtration step of filtering the melt-kneaded mixture using a filtration device, wherein the filtration device comprises a supply port for supplying the mixture and a filter having a filtration surface, wherein the filtration step comprises a primary filtration step of first filtering the mixture and a secondary filtration step of filtering the mixture after primary filtration using a filter with a finer mesh opening than that used in the primary filtration step, wherein at least one of the filtration devices performing the secondary filtration step has a flow path that widens from the supply port toward the filtration surface.

Description

[Technical Field]

[0001] The present invention relates to a method for producing a resin composition, a method for producing pellets, and a resin composition. [Background technology]

[0002] Molded articles containing resin compositions such as polypropylene are used in industrial parts such as automobile parts and electrical components, as well as in daily necessities and general merchandise. Such molded articles are obtained by using pellets as raw materials, supplying the pellets to an extrusion molding apparatus, melting and kneading them, and then extruding them.

[0003] Conventionally, when manufacturing pellets, the raw materials for the resin composition are melted and kneaded, and then the molten raw materials are filtered to remove foreign matter contained in the raw materials (for example, Patent Document 1). [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] Special Publication No. 2019-527618 [Overview of the project] [Problems that the invention aims to solve]

[0005] However, pellets produced by conventional methods have the problem of low surface impact strength in the resulting molded products. This problem is particularly pronounced when the molded products are used in cold climates, and improvement is desired.

[0006] This invention has been made in view of the above problems, and aims to provide a method for producing a resin composition, a method for producing pellets, and a resin composition that can produce a molded article with relatively excellent surface impact strength. [Means for solving the problem]

[0007] The manufacturing method of the resin composition according to the present invention includes a melt kneading step of melt kneading the raw materials of the resin composition, and a filtering step of filtering the melt kneaded kneaded material using a filtering device. The filtering device includes a supply port for supplying the kneaded material and a filter having a filtering surface. The filtering step includes a primary filtering step of first filtering the kneaded material, and a secondary filtering step of filtering the kneaded material that has undergone the primary filtering using a filter with a finer mesh size than that of the primary filtering step. At least one of the filtering devices for performing the secondary filtering step has a flow path that expands from the supply port toward the filtering surface.

[0008] The manufacturing method of the pellet according to the present invention includes a pelletizing step of extruding the resin composition obtained by the above-described manufacturing method of the resin composition using an extruder to obtain pellets.

[0009] The resin composition according to the present invention is obtained by the above-described manufacturing method of the resin composition.

Effects of the Invention

[0010] According to the present invention, it is possible to provide a manufacturing method of a resin composition, a manufacturing method of a pellet, and a resin composition capable of obtaining a molded body having relatively excellent surface impact strength.

Embodiments for Carrying Out the Invention

[0011] Hereinafter, embodiments of the present invention will be described, but the present invention is not limited to the following embodiments.

[0012] [Manufacturing Method of Resin Composition] The manufacturing method of the resin composition according to the present embodiment includes a melt kneading step of melt kneading the raw materials of the resin composition, and a filtering step of filtering the melt kneaded kneaded material using a filtering device.

[0013] <Melt Kneading Step> The raw materials for the resin composition include, for example, polyolefin resins such as ethylene polymers and propylene polymers, polyamide resins, polyester resins, polystyrene resins, and polycarbonate resins. From the viewpoint of improving the rigidity and impact resistance of the molded article, the raw materials for the resin composition preferably include propylene polymers.

[0014] A propylene polymer is a polymer containing 50% by mass or more monomer units derived from propylene. Examples of propylene polymers include propylene homopolymers, random copolymers of propylene and monomers other than propylene, and heterophagic propylene polymerization materials. From the viewpoint of improving the rigidity and impact resistance of the molded article, the raw materials of the resin composition preferably include a heterophagic propylene polymerization material as the propylene polymer. The raw materials of the resin composition may contain only one type of propylene polymer, or two or more types.

[0015] The isotactic pentad fraction of the propylene polymer is preferably 0.961 or higher, more preferably 0.965 or higher, and even more preferably 0.968 or higher. Furthermore, the isotactic pentad fraction of the propylene polymer is preferably 1.000 or lower, and more preferably 0.995 or lower.

[0016] The isotactic pentad fraction refers to the isotactic fraction in pentad units. In other words, the isotactic pentad fraction indicates the proportion of structures in which five monomer units derived from propylene are consecutively linked by mesobonding, when viewed in pentad units. If the component in question is a copolymer, it refers to the value measured for the chain of monomer units derived from propylene.

[0017] The isotactic pentad fraction is, 13 This is a value measured by a 1C-NMR spectrum. Specifically, 13 The ratio of the area of ​​the mmmm peak to the area of ​​the total absorption peak in the methyl carbon region obtained by 13C-NMR spectroscopy is defined as the isotactic pentad fraction.13 A method for measuring the isotactic pentad fraction using 1C-NMR spectroscopy is described, for example, in Macromolecules, 6, 925 (1973) by A. Zambelli et al. However, 13 The assignment of absorption peaks obtained by C-spectroscopy shall be based on the description in Macromolecules, 8, 687 (1975).

[0018] The isotactic pentad fraction of propylene polymers can be adjusted to the above range by appropriately selecting the catalyst, donor, polymerization conditions, etc. Furthermore, propylene polymers with the desired isotactic pentad fraction can be obtained from commercially available products.

[0019] The propylene polymer content may be 40% to 99% by mass, or 50% to 95% by mass, based on 100% by mass of the total mass of the raw materials of the resin composition.

[0020] (Propylene homopolymer) The propylene homopolymer preferably has an intrinsic viscosity number ([η]) of 0.10 dL / g or more and 4.00 dL / g or less, more preferably 0.50 dL / g or more and 3.00 dL / g or less, and even more preferably 0.70 dL / g or more and 2.00 dL / g or less, from the viewpoint of improving the fluidity of the resin composition when melted and the toughness of the molded article.

[0021] In this specification, the intrinsic viscosity number (unit: dL / g) is a value measured at a temperature of 135°C using tetralin as the solvent by the following method.

[0022] The reduced viscosity is measured at three points using an Ubbelohde viscometer at concentrations of 0.1 g / dL, 0.2 g / dL, and 0.5 g / dL. The reduced viscosity is plotted against the concentration, and the intrinsic viscosity number is determined by extrapolation, where the concentration is extrapolated to zero. The method for calculating the intrinsic viscosity number by extrapolation is described, for example, on page 491 of "Polymer Solutions, Polymer Experiments 11" (Kyoritsu Shuppan Co., Ltd., 1982).

[0023] The molecular weight distribution (Mw / Mn) of the propylene homopolymer is preferably 3.0 or higher, and more preferably 4.0 or higher. The molecular weight distribution of the propylene homopolymer is preferably 15.0 or lower, and more preferably 10.0 or lower. The molecular weight distribution of the propylene homopolymer is preferably 3.0 or higher and 15.0 or lower, and more preferably 4.0 or higher and 10.0 or lower.

[0024] In this specification, the molecular weight distribution refers to the ratio of the weight-average molecular weight (Mw) to the number-average molecular weight (Mn) (Mw / Mn), calculated using the weight-average molecular weight (Mw) and number-average molecular weight (Mn) measured by gel permeation chromatography (GPC) under the following conditions. Equipment: Tosoh Corporation HLC-8121 GPC / HT Separation columns: 3 GMHHR-H(S)HT columns manufactured by Tosoh Corporation. Measurement temperature: 140℃ Carrier: Orthodichlorobenzene Flow rate: 1.0mL / min Sample concentration: approximately 1 mg / mL Sample injection volume: 400 μL Detector: Differential refraction Calibration curve creation method: Standard polystyrene is used.

[0025] Propylene homopolymers can be produced, for example, by carrying out a polymerization process in which propylene is polymerized using a polymerization catalyst.

[0026] Examples of polymerization catalysts include Ziegler-type catalysts; Ziegler-Natta-type catalysts; catalysts containing compounds of Group 4 transition metals having a cyclopentadienyl ring and alkylaluminoxanes; catalysts containing compounds of Group 4 transition metals having a cyclopentadienyl ring, compounds that react with said transition metal compounds to form ionic complexes, and organoaluminum compounds; and catalysts modified by supporting catalyst components (compounds of Group 4 transition metals having a cyclopentadienyl ring, compounds that form ionic complexes, organoaluminum compounds, etc.) on inorganic particles (silica, clay minerals, etc.).

[0027] Examples of the polymerization catalyst include catalysts described in Japanese Patent Publication No. 61-218606, Japanese Patent Publication No. 5-194685, Japanese Patent Publication No. 7-216017, Japanese Patent Publication No. 9-316147, Japanese Patent Publication No. 10-212319, Japanese Patent Publication No. 2004-182981, Japanese Patent Publication No. 2010-168545, Japanese Patent Publication No. 2011-246699, and the like.

[0028] Furthermore, a polymer obtained by prepolymerizing propylene in the presence of the polymerization catalyst can also be used as the polymerization catalyst.

[0029] Polymerization methods include, for example, bulk polymerization, solution polymerization, and gas-phase polymerization. Here, bulk polymerization refers to a method in which polymerization is carried out using liquid olefins at the polymerization temperature as a medium. Solution polymerization refers to a method in which polymerization is carried out in an inert hydrocarbon solvent such as propane, butane, isobutane, pentane, hexane, heptane, and octane. Gas-phase polymerization refers to a method in which a monomer in a gaseous state is used as a medium to polymerize a monomer in a gaseous state within that medium.

[0030] Polymerization methods include, for example, batch, continuous, and combinations thereof. The polymerization method may also be a multi-stage system in which multiple polymerization reactors are connected in series.

[0031] From an industrial and economically superior viewpoint, the polymerization method is preferably a continuous gas-phase polymerization method, or a bulk-gas-phase polymerization method that sequentially performs bulk polymerization and gas-phase polymerization.

[0032] The various conditions in the polymerization process (polymerization temperature, polymerization pressure, monomer concentration, catalyst input amount, polymerization time, etc.) should be appropriately determined according to the molecular structure of the target polymer.

[0033] In the method for producing a propylene homopolymer, other steps may be performed before or after the polymerization step. For example, after the polymerization step, the polymer may be dried at a temperature below the melting point of the polymer, if necessary, in order to remove residual solvents contained in the polymer, ultra-low molecular weight oligomers produced as by-products during manufacturing, etc. Examples of drying methods include those described in Japanese Patent Publication No. 55-75410 and Japanese Patent No. 2565753.

[0034] (Random copolymer of propylene and other monomers) A random copolymer of propylene and a monomer other than propylene contains monomer units derived from propylene and monomer units derived from the monomer other than propylene. The random copolymer preferably contains 0.01% to 20% by mass of monomer units derived from the monomer other than propylene, based on 100% by mass of the total mass of the copolymer.

[0035] Examples of monomers other than propylene include ethylene and α-olefins having 4 to 12 carbon atoms. In this specification, α-olefins are aliphatic unsaturated hydrocarbons having a carbon-carbon unsaturated double bond at the α-position. Examples of α-olefins having 4 to 12 carbon atoms include 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 1-nonene, 1-decene, 1-dodecene, 4-methyl-1-pentene, and 4-methyl-1-hexene.

[0036] The monomer other than propylene is preferably at least one selected from the group consisting of ethylene and α-olefins having 4 to 10 carbon atoms, more preferably at least one selected from the group consisting of ethylene, 1-butene, 1-hexene and 1-octene, and even more preferably at least one selected from the group consisting of ethylene and 1-butene.

[0037] Examples of random copolymers of propylene and monomers other than propylene include propylene-ethylene random copolymer, propylene-1-butene random copolymer, propylene-1-hexene random copolymer, propylene-1-octene random copolymer, propylene-ethylene-1-butene random copolymer, propylene-ethylene-1-hexene random copolymer, and propylene-ethylene-1-octene random copolymer.

[0038] A random copolymer of propylene and a monomer other than propylene has an intrinsic viscosity number ([η]) of 0.10 dL / g to 4.00 dL / g, more preferably 0.50 dL / g to 3.00 dL / g, and even more preferably 0.70 dL / g to 2.00 dL / g, from the viewpoint of improving the fluidity of the propylene resin composition when melted.

[0039] The molecular weight distribution (Mw / Mn) of a random polymer of propylene and a monomer other than propylene is preferably 3.0 or higher, and more preferably 4.0 or higher. The molecular weight distribution of a random polymer of propylene and a monomer other than propylene is preferably 10.0 or lower, and more preferably 7.0 or lower. The molecular weight distribution of a random polymer of propylene and a monomer other than propylene is preferably 3.0 or higher and 10.0 or lower, and more preferably 4.0 or higher and 7.0 or lower.

[0040] Random copolymers of propylene and monomers other than propylene can be produced, for example, by polymerizing propylene and monomers other than propylene according to the polymerization catalyst, polymerization method, polymerization scheme, and polymerization conditions that can be used in the production of the propylene homopolymer described above.

[0041] (Heterophagic propylene polymerization material) The heterophagic propylene polymerization material is a mixture comprising polymer I containing 80% by mass or more monomer units derived from propylene (provided that the total mass of polymer I is 100% by mass), and polymer II containing monomer units derived from ethylene and at least one α-olefin selected from the group consisting of α-olefins having 4 to 12 carbon atoms, and monomer units derived from propylene.

[0042] A heterophagic propylene polymerization material can be produced, for example, by carrying out a first polymerization step of polymer I and a second polymerization step of polymer II. These polymerization steps can be carried out according to the polymerization catalyst, polymerization method, polymerization scheme, and polymerization conditions that can be used in the production of the propylene homopolymer described above.

[0043] The heterophagic propylene polymerization material may be such that the sum of polymer I and polymer II contained in the heterophagic propylene polymerization material is 100% by mass, relative to 100% by mass of the total mass of the heterophagic propylene polymerization material.

[0044] As described above, polymer I contains 80% by mass or more of monomer units derived from propylene (where the total mass of polymer I is 100% by mass). Polymer I may be, for example, a propylene homopolymer, or it may contain monomer units derived from monomers other than propylene. If polymer I contains monomer units derived from monomers other than propylene, the content may be, for example, 0.01% by mass or more and less than 20% by mass, relative to 100% by mass of the total mass of polymer I.

[0045] Examples of monomers other than propylene include ethylene and α-olefins having four or more carbon atoms. Examples of α-olefins having four or more carbon atoms include 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 1-nonene, 1-decene, 1-dodecene, 4-methyl-1-pentene, and 4-methyl-1-hexene.

[0046] The monomer other than propylene is preferably at least one selected from the group consisting of ethylene and α-olefins having 4 to 10 carbon atoms, more preferably at least one selected from the group consisting of ethylene, 1-butene, 1-hexene and 1-octene, and even more preferably at least one selected from the group consisting of ethylene and 1-butene.

[0047] Examples of polymer I containing monomer units derived from monomers other than propylene include propylene-ethylene copolymer, propylene-1-butene copolymer, propylene-1-hexene copolymer, propylene-1-octene copolymer, propylene-ethylene-1-butene copolymer, propylene-ethylene-1-hexene copolymer, and propylene-ethylene-1-octene copolymer.

[0048] From the viewpoint of improving the dimensional stability of the molded article, polymer I is preferably a propylene homopolymer, a propylene-ethylene copolymer, a propylene-1-butene copolymer, or a propylene-ethylene-1-butene copolymer, and more preferably a propylene homopolymer.

[0049] The isotactic pentad fraction of polymer I is preferably 1.000 or less, and may be, for example, 0.998 or less, 0.995 or less, 0.990 or less, or 0.985 or less. The lower limit of the isotactic pentad fraction is not particularly limited, but may be, for example, 0.900 or more, 0.925 or more, 0.930 or more, 0.961 or more, 0.965 or more, or 0.968 or more.

[0050] The content of polymer I is preferably 50% to 99% by mass, and more preferably 60% to 95% by mass, based on 100% by mass of the total mass of the heterophagic propylene polymerization material.

[0051] As described above, polymer II contains monomer units derived from ethylene and at least one α-olefin selected from the group consisting of α-olefins having 4 to 12 carbon atoms, and monomer units derived from propylene. Examples of α-olefins having 4 to 12 carbon atoms include 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 1-nonene, 1-decene, 1-dodecene, 4-methyl-1-pentene, and 4-methyl-1-hexene.

[0052] Polymer II preferably contains 30% by mass or more monomer units derived from ethylene and at least one α-olefin selected from the group consisting of α-olefins having 4 to 12 carbon atoms, and also contains monomer units derived from propylene (provided the total mass of Polymer II is 100% by mass).

[0053] In polymer II, the content of monomer units derived from ethylene and at least one α-olefin selected from the group consisting of α-olefins having 4 to 12 carbon atoms may be 30% by mass or more and 70% by mass or less, or 35% by mass or more and 60% by mass or less (provided that the total mass of polymer II is 100% by mass).

[0054] In polymer II, the at least one α-olefin selected from the group consisting of ethylene and α-olefins having 4 to 12 carbon atoms is preferably at least one selected from the group consisting of ethylene and α-olefins having 4 to 10 carbon atoms, more preferably at least one selected from the group consisting of ethylene, 1-butene, 1-hexene, 1-octene and 1-decene, and even more preferably at least one selected from the group consisting of ethylene and 1-butene.

[0055] Examples of polymer II include propylene-ethylene copolymer, propylene-ethylene-1-butene copolymer, propylene-ethylene-1-hexene copolymer, propylene-ethylene-1-octene copolymer, propylene-ethylene-1-decene copolymer, propylene-1-butene copolymer, propylene-1-hexene copolymer, propylene-1-octene copolymer, and propylene-1-decene copolymer. Among these, polymer II is preferably propylene-ethylene copolymer, propylene-1-butene copolymer, or propylene-ethylene-1-butene copolymer, and more preferably propylene-ethylene copolymer.

[0056] The content of polymer II is preferably 1% to 50% by mass, and more preferably 5% to 40% by mass, based on 100% by mass of the total mass of the heterophagic propylene polymerization material.

[0057] In the heterophagic propylene polymerization material, the content of monomer units derived from ethylene and at least one α-olefin selected from the group consisting of α-olefins having 4 to 12 carbon atoms may be 0.3% by mass or more and 35% by mass or less, or 0.7% by mass or more and 24% by mass or less (provided that the total mass of the heterophagic propylene polymerization material is 100% by mass).

[0058] The content of xylene-insoluble components (CXIS components) in the heterophagic propylene polymerization material is preferably 50% to 99% by mass, and more preferably 60% to 95% by mass, based on 100% by mass of the total mass of the heterophagic propylene polymerization material.

[0059] The content of xylene-soluble components (CXS components) in the heterophagic propylene polymerization material is preferably 1% to 50% by mass, and more preferably 5% to 40% by mass, based on 100% by mass of the total mass of the heterophagic propylene polymerization material.

[0060] In this specification, xylene-insoluble components (CXIS components) refer to components insoluble in p-xylene contained in the polymer, and are solids obtained by the following method: A method for precipitating solid material by dissolving approximately 2 g of polymer in boiling p-xylene for 2 hours to obtain a solution, and then cooling the solution to 20°C.

[0061] Furthermore, in this specification, xylene-soluble components (CXS components) refer to components in the polymer other than the "CXIS components".

[0062] In this embodiment, the CXIS component in the heterophagic propylene polymerization material is considered to be mainly composed of polymer I, and the CXS component in the heterophagic propylene polymerization material is considered to be mainly composed of polymer II.

[0063] Examples of heterophagic propylene polymerization materials include (propylene)-(propylene-ethylene) polymerization materials, (propylene)-(propylene-ethylene-1-butene) polymerization materials, (propylene)-(propylene-ethylene-1-hexene) polymerization materials, (propylene)-(propylene-ethylene-1-octene) polymerization materials, (propylene)-(propylene-1-butene) polymerization materials, (propylene)-(propylene-1-hexene) polymerization materials, (propylene)-(propylene-1-octene) polymerization materials, and (propylene)-(propylene-1-decene) polymerization materials. Polymerization material, (propylene-ethylene)-(propylene-ethylene) polymerization material, (propylene-ethylene)-(propylene-ethylene-1-butene) polymerization material, (propylene-ethylene)-(propylene-ethylene-1-hexene) polymerization material, (propylene-ethylene)-(propylene-ethylene-1-octene) polymerization material, (propylene-ethylene)-(propylene-ethylene-1-decene) polymerization material, (propylene-ethylene)-(propylene-1-butene) polymerization material, (propylene-ethylene)-(propylene-1-hexene) polymerization material, (propylene-ethylene (propylene-1-octene) polymerization material, (propylene-ethylene)-(propylene-1-decene) polymerization material, (propylene-1-butene)-(propylene-ethylene) polymerization material, (propylene-1-butene)-(propylene-ethylene-1-butene) polymerization material, (propylene-1-butene)-(propylene-ethylene-1-hexene) polymerization material, (propylene-1-butene)-(propylene-ethylene-1-octene) polymerization material, (propylene-1-butene)-(propylene-ethylene-1-decene) polymerization material, (propylene-1-butene)-( (Propylene-1-butene) polymerization material, (Propylene-1-butene)-(Propylene-1-hexene) polymerization material, (Propylene-1-butene)-(Propylene-1-octene) polymerization material, (Propylene-1-butene)-(Propylene-1-decene) polymerization material, (Propylene-1-hexene)-(Propylene-1-hexene) polymerization material, (Propylene-1-hexene)-(Propylene-1-octene) polymerization material, (Propylene-1-hexene)-(Propylene-1-decene) polymerization material, (Propylene-1-octene)-(Propylene-1-octene) polymerization material,Examples include (propylene-1-octene)-(propylene-1-decene) polymerization materials.

[0064] Here, the description "(propylene)-(propylene-ethylene) polymerization material" means "a heterophagous propylene polymerization material in which polymer I is a propylene homopolymer and polymer II is a propylene-ethylene copolymer." The same applies to other similar expressions.

[0065] The heterophagic propylene polymerization material is preferably a (propylene)-(propylene-ethylene) polymerization material, a (propylene)-(propylene-ethylene-1-butene) polymerization material, a (propylene-ethylene)-(propylene-ethylene) polymerization material, a (propylene-ethylene)-(propylene-ethylene-1-butene) polymerization material, or a (propylene-1-butene)-(propylene-1-butene) polymerization material, and more preferably a (propylene)-(propylene-ethylene) polymerization material.

[0066] The intrinsic viscosity number ([η]I) of polymer I is preferably 0.10 dL / g or more and 4.00 dL / g or less, more preferably 0.50 dL / g or more and 3.00 dL / g or less, and even more preferably 0.70 dL / g or more and 2.00 dL / g or less.

[0067] The intrinsic viscosity number ([η]II) of polymer II is preferably 1.00 dL / g or more and 10.00 dL / g or less, more preferably 2.00 dL / g or more and 10.00 dL / g or less, and even more preferably 2.00 dL / g or more and 9.00 dL / g or less.

[0068] Furthermore, the ratio of the intrinsic viscosity number of polymer II ([η]II) to the intrinsic viscosity number of polymer I ([η]I) ([η]II / [η]I) is preferably 1 to 20, and more preferably 1 to 10.

[0069] One method for measuring the intrinsic viscosity number ([η]I) of polymer I is to extract the polymerized polymer I from the reactor in which it is polymerized and measure the intrinsic viscosity number of the polymer.

[0070] The intrinsic viscosity number of polymer II ([η]II) can be calculated, for example, using the intrinsic viscosity number of the heterophagic propylene polymerization material ([η]Total), the intrinsic viscosity number of polymer I ([η]I), and the content of polymer II and polymer I, by the following formula (i).

[0071] [η]II=([η]Total-[η]I×XI) / XII ···(i) [η] Total: Intrinsic viscosity number (dL / g) of heterophagic propylene polymerization material [η]I: Intrinsic viscosity number of polymer I (dL / g) XI: Ratio of the mass of polymer I to the total mass of heterophagic propylene polymerization material (mass of polymer I / mass of heterophagic propylene polymerization material) XII: Ratio of the mass of polymer II to the total mass of heterophagic propylene polymerization material (mass of polymer II / mass of heterophagic propylene polymerization material)

[0072] Here, XI and XII can be determined from the mass balance during polymerization.

[0073] Furthermore, XII may be calculated by measuring the heat of fusion of polymer I and the heat of fusion of the heterophagic propylene polymerization material and using the following formula. XII = 1 - (ΔHf)T / (ΔHf)P (ΔHf)T: Heat of fusion of heterophagic propylene polymerization material (J / g) (ΔHf)P: Heat of fusion of polymer I (J / g)

[0074] The intrinsic viscosity number ([η]CXIS) of the CXIS component is preferably 0.10 dL / g or more and 4.00 dL / g or less, more preferably 0.50 dL / g or more and 3.00 dL / g or less, and even more preferably 0.70 dL / g or more and 2.00 dL / g or less.

[0075] The intrinsic viscosity number ([η]CXS) of the CXS component is preferably 1.00 dL / g or more and 10.00 dL / g or less, more preferably 2.00 dL / g or more and 10.00 dL / g or less, and even more preferably 2.00 dL / g or more and 9.00 dL / g or less.

[0076] The ratio of the intrinsic viscosity number of the CXS component ([η]CXS) to the intrinsic viscosity number of the CXIS component ([η]CXIS) ([η]CXS / [η]CXIS) is preferably 1 to 20, and more preferably 1 to 10.

[0077] The molecular weight distribution (Mw(I) / Mn(I)) of polymer I is preferably 3.0 or higher, and more preferably 4.0 or higher.

[0078] The molecular weight distribution of the CXIS component (Mw(CXIS) / Mn(CXIS)) is preferably 3.0 or higher, and more preferably 4.0 or higher.

[0079] The melt flow rate (MFR) of the propylene polymer is preferably 0.1 g / 10 min or more, and more preferably 1 g / 10 min or more and 300 g / 10 min or less, from the viewpoint of improving the moldability of the resin composition. The melt flow rate (MFR) of the propylene polymer may be 5 g / 10 min or more and 100 g / 10 min or less, or 10 g / 10 min or more and 50 g / 10 min or less.

[0080] In this specification, the melt flow rate (MFR) of propylene polymers is measured by Method A, under the conditions of a temperature of 230°C and a load of 2.16 kg, in accordance with the method specified in JIS K7210-1995.

[0081] The raw materials for the resin composition may be crushed material. Crushed material is obtained by crushing a molded body. The molded body may be one that has been recovered from the market. Examples of raw materials for recovered crushed material include automotive parts, packaging containers (food retort pouches, refill pouches, detergent bottles, etc.), housings for household electrical appliances, office supplies (trays, etc.), and household daily necessities (contact lens cases, etc.). Examples of automotive parts include interior parts of automobiles (instrument panels, door trims, etc.), exterior parts of automobiles (bumpers, pillars, etc.), and other automotive parts (battery cases, etc.).

[0082] When the raw material for the resin composition is crushed material, the raw material for the resin composition preferably further comprises a virgin propylene polymer from the viewpoint of improving the rigidity and impact resistance of the molded article. A virgin propylene polymer means a propylene polymer that has not been molded into products or parts such as automobiles after being produced by a process including a polymerization step, and has not been used for any end use.

[0083] The content of virgin propylene polymer is preferably 15% by mass or more, and more preferably 30% by mass or more, based on 100% by mass of the total mass of the raw materials of the resin composition. The content of virgin propylene polymer is preferably 85% by mass or less, and more preferably 70% by mass or less, based on 100% by mass of the total mass of the raw materials of the resin composition.

[0084] Furthermore, if the raw material of the resin composition is crushed material, the raw material of the resin composition preferably further contains an ethylene-α-olefin copolymer from the viewpoint of improving impact resistance. The raw material of the resin composition may also contain recycled ethylene-α-olefin copolymer as the ethylene-α-olefin copolymer. Recycled ethylene-α-olefin copolymer refers to an ethylene-α-olefin copolymer that has been processed such as molding, or used for some final purpose, and then reused after going through a recovery process.

[0085] The ethylene-α-olefin copolymer may also be an ethylene-α-olefin random copolymer. Note that the ethylene-α-olefin copolymer is a copolymer containing monomer units derived from ethylene and monomer units derived from α-olefins having 4 or more carbon atoms, and substantially free of monomer units derived from propylene.

[0086] The ethylene-α-olefin copolymer may have a total content of monomer units derived from ethylene and monomer units derived from α-olefins having 4 or more carbon atoms, which may be 100% by mass, based on 100% by mass of the total mass of the copolymer.

[0087] Examples of α-olefins having 4 or more carbon atoms include α-olefins having 4 to 12 carbon atoms. Examples of α-olefins having 4 to 12 carbon atoms include 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 1-octene, and 1-decene. The α-olefin having 4 to 12 carbon atoms is preferably 1-butene, 1-hexene, or 1-octene. The α-olefin having 4 to 12 carbon atoms may also be an α-olefin having a cyclic structure, such as vinylcyclopropane or vinylcyclobutane.

[0088] Examples of ethylene-α-olefin copolymers include ethylene-1-butene copolymer, ethylene-1-hexene copolymer, ethylene-1-octene copolymer, ethylene-1-decene copolymer, ethylene-(3-methyl-1-butene) copolymer, and copolymers of ethylene and α-olefins having a cyclic structure.

[0089] In the ethylene-α-olefin copolymer, the content of monomer units derived from α-olefins having 4 or more carbon atoms is preferably 1% to 49% by mass, more preferably 5% to 49% by mass, and even more preferably 24% to 49% by mass, based on 100% by mass of the total mass of the ethylene-α-olefin copolymer.

[0090] From the viewpoint of the impact resistance of the molded article, the density of the ethylene-α-olefin copolymer is preferably 0.850 g / cm 3 or more and 0.890 g / cm 3 or less, more preferably 0.850 g / cm 3 or more and 0.880 g / cm 3 or less, still more preferably 0.850 g / cm 3 or more and 0.870 g / cm 3 or less.

[0091] The melt flow rate of the ethylene-α-olefin copolymer at a temperature of 190 °C and a load of 2.16 kg is preferably 0.1 g / 10 min or more and 80 g / 10 min or less. The melt flow rate of the ethylene-α-olefin copolymer can be measured by Method A under the conditions of a temperature of 190 °C and a load of 2.16 kg in accordance with the method specified in JIS K7210-1995.

[0092] The content of the ethylene-α-olefin copolymer is preferably 1% by mass or more, more preferably 5% by mass or more, based on 100% by mass of the total mass of the raw materials of the resin composition. Also, the content of the ethylene-α-olefin copolymer is preferably 40% by mass or less, more preferably 30% by mass or less, based on 100% by mass of the total mass of the raw materials of the resin composition.

[0093] The ethylene-α-olefin copolymer can be produced by polymerizing ethylene and an α-olefin having 4 or more carbon atoms using a polymerization catalyst.

[0094] Examples of the polymerization catalyst include homogeneous catalysts typified by metallocene catalysts, Ziegler-Natta type catalysts, and the like.

[0095] Examples of homogeneous catalysts include catalysts containing compounds of Group 4 transition metals having a cyclopentadienyl ring and alkylaluminoxanes; catalysts containing compounds of Group 4 transition metals having a cyclopentadienyl ring, compounds that react with the transition metal compounds to form ionic complexes, and organoaluminum compounds; and catalysts modified by supporting catalyst components (compounds of Group 4 transition metals having a cyclopentadienyl ring, compounds that form ionic complexes, organoaluminum compounds, etc.) on inorganic particles (silica, clay minerals, etc.).

[0096] Examples of Ziegler-Natta type catalysts include catalysts that combine a titanium-containing solid transition metal component with an organometallic component.

[0097] Commercially available ethylene-α-olefin copolymers may be used. Examples of commercially available ethylene-α-olefin copolymers include Engage® manufactured by Dow Chemical Japan Ltd., Tuffmer® manufactured by Mitsui Chemicals, Inc., Neozex® and Ultzex® manufactured by Prime Polymer Co., Ltd., and Excellen FX®, Sumikasen®, and Esprene SPO® manufactured by Sumitomo Chemical Co., Ltd.

[0098] The raw materials of the resin composition may further contain other components. Examples of other components include neutralizing agents, antioxidants, ultraviolet absorbers, nucleating agents, lubricants, antistatic agents, antiblocking agents, processing aids, organic peroxides, colorants (inorganic pigments, organic pigments, pigment dispersants, etc.), foaming agents, foaming nucleating agents, plasticizers, flame retardants, crosslinking agents, crosslinking aids, brightness enhancers, antibacterial agents, light diffusing agents, and the like.

[0099] In the melt-mixing process, the temperature during melt-mixing may be 180°C or higher, 180°C to 300°C, or 180°C to 250°C.

[0100] For melt mixing, a Banbury mixer, a single-screw extruder, a twin-screw co-rotating extruder, etc., can be used. The raw materials for the resin composition are, for example, fed in from a hopper, weighed in a weighing section, and then sent to the extruder, etc., via a feeder. If the raw materials for the resin composition are crushed material, a mechanism may be provided to feed the crushed material, which has been crushed using a crushing device such as a cutter compactor, into the hopper, or the crushed material may be crushed at another location and then fed into the hopper. The crushed material is, for example, crushed to 15 mm or less.

[0101] The order in which each raw material component is mixed is not particularly limited. For example, all components may be mixed together at once, or some components may be mixed first, and then the resulting mixture may be mixed with the other components.

[0102] <Filtration process> The filtration process includes a primary filtration step in which the kneaded material is first filtered, and a secondary filtration step in which the kneaded material that has undergone primary filtration is filtered using a filter with a finer mesh than that used in the primary filtration step.

[0103] The filtration apparatus used in the filtration process comprises a supply port for supplying the kneaded material and a filter having a filtration surface. More specifically, the supply port is located opposite the filtration surface, and a space is provided between the supply port and the filtration surface.

[0104] In at least one of the filtration devices performing the secondary filtration process, the flow path is widened from the supply port toward the filtration surface. With this configuration, most of the fibrous foreign matter contained in the kneaded material enters the filtration surface at an angle, making it difficult for it to pass through the filter. As a result, a large amount of fibrous foreign matter contained in the kneaded material can be removed, and a molded body with excellent surface impact strength can be obtained. Note that there may be multiple filtration devices performing the secondary filtration process, and it is sufficient that at least one of them has a widened flow path from the supply port toward the filtration surface.

[0105] Preferably, at least one of the filtration devices performing the secondary filtration step has a V / S of less than 1 cm and an S / A of 20 or more. By having an enlarged flow path in at least one of the filtration devices performing the secondary filtration step such that the V / S is less than 1 cm and the S / A is 20 or more, more fibrous foreign matter contained in the kneaded material can be removed, thus enabling the production of a molded product with superior surface impact strength. The V / S is more preferably 0.01 cm to 0.7 cm, and even more preferably 0.1 cm to 0.5 cm. Furthermore, the S / A is more preferably 22 to 150, and even more preferably 25 to 100.

[0106] Here, V is the volume of the space from the supply port to the filtration surface, for example, 10 cm³. 3 More than 40000cm 3 The following is possible: S is the area of ​​the filtration surface, for example, 10 cm². 2 More than 2000cm 2 The following is possible: A is the area of ​​the supply port, that is, the area projected onto a plane parallel to the filtration surface of the supply port, for example, 10 cm². 2 More than 2000cm 2 The following is possible:

[0107] In at least one of the filtration devices performing the secondary filtration step, the ratio of the area of ​​the filtration surface to the amount of kneaded material supplied is preferably 0.1 cm². 2 ·hr / kg or more 0.4cm 2 • Less than or equal to hr / kg, more preferably 0.2cm 2 ·hr / kg or more 0.3cm 2 • Less than hr / kg

[0108] The filtration apparatus for the secondary filtration process can consist of, for example, one to five units, and preferably one to two units.

[0109] The filtration device performing the primary filtration step has a S / A ratio of preferably 1 to 10, and more preferably 1. That is, the filtration device performing the primary filtration step preferably does not have a flow path that widens from the supply port toward the filtration surface. With this configuration, the filtration device performing the primary filtration step can remove relatively large foreign matter, and therefore the filtration device performing the subsequent secondary filtration step can efficiently remove fibrous foreign matter.

[0110] In a filtration system that performs the primary filtration process, for example, V is set to 50 cm 3 More than 40000cm 3 Below, S is 10cm 2 More than 2000cm 2 Below, A is 10cm 2 More than 2000cm 2 The following is possible:

[0111] The mesh size of the filter in the filtration device performing the primary filtration step is preferably 70 μm or more, and more preferably 80 μm to 200 μm. The mesh size of the filter in the filtration device performing the secondary filtration step is preferably 10 μm to 60 μm, and more preferably 20 μm to 40 μm. In one embodiment, the method for producing the resin composition according to this embodiment yields a molded article with excellent surface impact strength, so the mesh size of the filter in the filtration device performing the primary filtration step is 70 μm or more, and the mesh size of the filter in the filtration device performing the secondary filtration step is 10 μm to 60 μm.

[0112] The material of the filter is not particularly limited; for example, stainless steel, copper, nickel, polypropylene, polyethylene, polyethylene terephthalate, etc., can be used.

[0113] In the resin composition manufacturing method according to this embodiment, a booster pump may be provided between the filtration device that performs the primary filtration step and the filtration device that performs the secondary filtration step in the filtration step. With this configuration, the resin composition manufacturing method can perform the primary filtration step and the secondary filtration step continuously and efficiently.

[0114] The method for producing a resin composition according to this embodiment includes a melt-kneading step of melt-kneading the raw materials of the resin composition, and a filtration step of filtering the melt-kneaded mixture using a filtration device, wherein the filtration device comprises a supply port for supplying the mixture and a filter having a filtration surface, wherein the filtration step includes a primary filtration step of first filtering the mixture and a secondary filtration step of filtering the mixture that has undergone primary filtration using a filter with a finer mesh opening than that of the primary filtration step, wherein at least one of the filtration devices performing the secondary filtration step has a flow path that expands from the supply port toward the filtration surface, thereby enabling the production of a molded body with relatively excellent surface impact strength.

[0115] [Pellet manufacturing method] The pellet manufacturing method according to this embodiment includes a pelletizing step in which the resin composition obtained by the resin composition manufacturing method described above is extruded using an extruder to obtain pellets. More specifically, in the pellet manufacturing method, the resin composition described above may be extruded from the die holes of an extruder to form strands. Alternatively, the obtained strands may be guided to a cooling water tank for cooling. Furthermore, pellets may be obtained by cutting the cooled strands with a strand cutter.

[0116] The method for producing the pellets includes a pelletizing step in which the resin composition obtained by the above-described method for producing the resin composition is extruded by an extruder to obtain pellets, thereby enabling the production of a molded article with excellent surface impact strength using the obtained pellets.

[0117] [Resin composition] The resin composition according to this embodiment is obtained by the method for manufacturing the resin composition described above. By obtaining the resin composition by the method for manufacturing the resin composition described above, a molded article with excellent surface impact strength can be obtained using the resin composition.

[0118] The resin composition obtained by the above-described method for producing the resin composition can be molded, for example, by injection molding to obtain a molded article.

[0119] Examples of injection molding methods include general injection molding, injection foam molding, supercritical injection foam molding, ultra-high-speed injection molding, injection compression molding, gas-assisted injection molding, sandwich molding, sandwich foam molding, and insert / outsert molding. The shape of the injection-molded article is not particularly limited. The injection-molded article can be used for applications such as automotive materials, home appliance materials, and containers, and is preferably used for automotive interior and exterior applications.

[0120] The present invention includes the following embodiments. [1] A melt-kneading step in which the raw materials of the resin composition are melt-kneaded, The process includes a filtration step in which the melted and kneaded mixture is filtered using a filtration device, The filtration device comprises a supply port for supplying the kneaded material and a filter having a filtration surface. The filtration process includes a primary filtration step in which the kneaded material is first filtered, and a secondary filtration step in which the kneaded material that has undergone primary filtration is filtered using a filter with a finer mesh size than that used in the primary filtration step. A method for manufacturing a resin composition, wherein at least one of the filtration devices that perform the secondary filtration step has a flow path that expands from the supply port toward the filtration surface. [2] In the filtration device, when the volume of the space from the supply port to the filtration surface is V, the area of ​​the filtration surface is S, and the area of ​​the supply port is A, The method for producing a resin composition according to [1], wherein at least one of the filtration devices that perform the secondary filtration step has a V / S of less than 1 cm and an S / A of 20 or more. [3] A method for producing the resin composition according to [1] or [2], wherein the raw material of the resin composition comprises a propylene polymer. [4] A method for producing the resin composition according to [3], wherein the raw materials for the resin composition include a heterophagic propylene polymerization material as the propylene polymer. [5] A method for producing a resin composition according to any one of [1] to [4], wherein a booster pump is provided between the filtration device that performs the primary filtration step and the filtration device that performs the secondary filtration step in the filtration step. [6] A method for producing a resin composition according to any one of [1] to [5], wherein the mesh size of the filter in the filtration device that performs the primary filtration step is 70 μm or larger, and the mesh size of the filter in the filtration device that performs the secondary filtration step is 10 μm or larger and 60 μm or smaller. [7] In at least one of the filtration devices that perform the secondary filtration step, the ratio of the area of ​​the filtration surface to the amount of kneaded material supplied is 0.1 cm 2 ·hr / kg or more 0.4cm 2 A method for producing the resin composition described in any one of [1] to [6], wherein the concentration is hr / kg or less. [8] A method for producing a resin composition according to any one of [1] to [7], wherein the raw material of the resin composition is crushed material. [9] A method for producing the resin composition according to [8], wherein the raw material for the resin composition further comprises a virgin propylene polymer.

[10] A method for producing the resin composition according to [8], wherein the raw material for the resin composition further comprises an ethylene-α-olefin copolymer.

[11] A method for producing the resin composition according to

[10] , wherein the raw materials for the resin composition include a recycled ethylene-α-olefin copolymer as an ethylene-α-olefin copolymer. A method for producing pellets, comprising a pelletizing step of extruding a resin composition obtained by any one of the methods for producing a resin composition described in

[12] [1] to

[11] using an extruder to obtain pellets. A resin composition obtained by a method for producing a resin composition described in any one of

[13] [1] to

[11] . [Examples]

[0121] The present invention will be described in more detail below with reference to examples. However, the present invention is not limited to these examples.

[0122] The following raw materials were used in the examples and comparative examples. Sample 1 (Examples 1, 2, Comparative Example 1): Automotive pillar material crushed to less than 15 mm (resin composition containing a propylene polymer) Sample 2 (Examples 3, 4, Comparative Example 2): Automotive bumper material crushed to less than 15 mm (resin composition containing a propylene polymer)

[0123] (Examples 1, 3, 4) The sample was supplied to a single-screw extruder at a total feed rate of 450 kg / hr and melted at a cylinder temperature of 200°C. Next, the molten sample was filtered through a first-stage filter (set temperature 200°C) connected to the tip of the extruder (primary filtration step), then filtered through a second-stage filter via a screw pump (secondary filtration step), and finally filtered through a diverter valve. From a die connected downstream of the diverter valve, the sample was granulated and cooled to solidify through an underwater cut type granulation unit.

[0124] Details of each filter are shown below. Note that S is the area of ​​the filtration surface, A is the area of ​​the supply port, and V is the volume of the space from the supply port to the filtration surface. First filter stage: S=1200cm 2 A = 1200 cm 2 V = 37000 cm 3 , filter mesh opening 80μm Second filter: S=1480cm 2 A = 19.6 cm 2 V=560cm 3 , filter mesh opening 20 or 40 μm

[0125] (Example 2) The sample filtered using the first-stage filter (primary filtration process) described above was supplied to a 35 mm single-screw extruder at a total feed rate of 20 kg / hr and melted at a cylinder temperature of 200°C. Next, the molten sample was fed through a filter (S=100 cm) connected to the tip of the extruder. 2 A = 4.9 cm 2 V=30cm 3 The mixture was filtered through a filter with a mesh size of 20 μm (secondary filtration step), and then the stranded resin was cooled in a strand bath and atomized using a pelletizer.

[0126] (Comparative Examples 1 and 2) The sample was fed into a 40mm single-screw extruder at a total feed rate of 10 kg / hr and melted at a cylinder temperature of 200°C. Next, the molten sample was passed through a mesh filter (S=12.5cm) connected to the tip of the extruder. 2 A = 12.5 cm 2 V=50cm 3 The first filtration was performed using a filter with a mesh opening of 80 μm, and the resulting stranded resin was cooled in a strand bath and then atomized using a pelletizer. Subsequently, the mesh opening of the aforementioned mesh filter was changed to 10 μm, and a second filtration was performed.

[0127] <Manufacturing of injection-molded parts for puncture impact testing and evaluation> The pelletized resin compositions obtained in each example and comparative example were injection-molded under the following conditions within the range described in JIS K7152 to produce injection-molded articles for puncture impact test evaluation. The resin composition molten in the injection molding machine was supplied from the gate into the mold cavity by the injection molding machine using a small rectangular plate type D12 mold described in JIS K7139. Injection molding machine: SE130DU manufactured by Sumitomo Heavy Industries, Ltd. Cylinder temperature: 197℃ Mold temperature: 40℃ Injection speed: 13.5mm / sec Cooling time: 8 seconds Molding cycle: 60 seconds Injection molded part: Type D12 flat plate (60mm long x 60mm wide x 2mm thick)

[0128] <Evaluation of puncture impact test> The puncture energy (in J) of the obtained flat molded body was measured using a HITS-P10 manufactured by Shimadzu Science East Japan Co., Ltd. under the following conditions. Stracker diameter: 1 / 2 inch Holder diameter: 1.5 inches Measurement speed: 2.8m / sec Measurement temperature: 23℃, -30℃ Measurements: Calculate the average value for N=6.

[0129] [Table 1]

[0130] As can be seen from the results in Table 1, the molded articles obtained by the manufacturing methods of each embodiment that satisfy all the constituent requirements of the present invention exhibit excellent surface impact strength, and in particular, excellent surface impact strength in an environment of -30°C, which is assumed to be a cold region.

Claims

1. A melt-kneading step in which the raw materials of the resin composition are melt-kneaded, The process includes a filtration step in which the melted and kneaded mixture is filtered using a filtration device, The filtration device comprises a supply port for supplying the kneaded material and a filter having a filtration surface. The filtration process includes a primary filtration step in which the kneaded material is first filtered, and a secondary filtration step in which the kneaded material that has undergone primary filtration is filtered using a filter with a finer mesh size than that used in the primary filtration step. A method for manufacturing a resin composition, wherein at least one of the filtration devices that perform the secondary filtration step has a flow path that expands from the supply port toward the filtration surface.

2. In the filtration device described above, when the volume of the space from the supply port to the filtration surface is V, the area of ​​the filtration surface is S, and the area of ​​the supply port is A, The method for producing a resin composition according to claim 1, wherein at least one of the filtration devices performing the secondary filtration step has a V / S of less than 1 cm and an S / A of 20 or more.

3. A method for producing the resin composition according to claim 1, wherein the raw material of the resin composition includes a propylene polymer.

4. The method for producing the resin composition according to claim 3, wherein the raw materials for the resin composition include a heterophagic propylene polymerization material as the propylene polymer.

5. A method for producing a resin composition according to claim 1, wherein a booster pump is provided between the filtration device that performs the primary filtration step and the filtration device that performs the secondary filtration step in the filtration step.

6. A method for producing a resin composition according to claim 1, wherein the mesh size of the filter in the filtration device that performs the primary filtration step is 70 μm or larger, and the mesh size of the filter in the filtration device that performs the secondary filtration step is 10 μm or larger and 60 μm or smaller.

7. In at least one of the filtration devices that perform the secondary filtration step, the ratio of the area of ​​the filtration surface to the amount of kneaded material supplied is 0.1 cm². ２ ・HR / kg or more 0.4cm ２ A method for producing the resin composition according to claim 1, wherein the hr / kg is 1 or less.

8. A method for producing a resin composition according to claim 1, wherein the raw material for the resin composition is a crushed material.

9. A method for producing a resin composition according to claim 8, wherein the raw materials for the resin composition further comprise a virgin propylene polymer.

10. A method for producing a resin composition according to claim 8, wherein the raw material for the resin composition further comprises an ethylene-α-olefin copolymer.

11. A method for producing a resin composition according to claim 10, wherein the raw materials for the resin composition include a recycled ethylene-α-olefin copolymer as an ethylene-α-olefin copolymer.

12. A method for producing pellets, comprising a pelletizing step of extruding a resin composition obtained by a method for producing a resin composition according to any one of claims 1 to 11 using an extruder to obtain pellets.

13. A resin composition obtained by a method for producing a resin composition according to any one of claims 1 to 11.

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