Polyolefin polymer compositions and molded articles

Abstract

The present invention provides a polyolefin polymer composition that maintains excellent moldability while meeting the explosion resistance performance requirements of the UL2596 BETR test, and a molded article containing the same. [Solution] A polyolefin polymer composition comprising (A) a polyolefin polymer, (B) a flame retardant, and (C) glass fibers, wherein the mass ratio of the content of (B) flame retardant to the content of (C) glass fibers [(B) flame retardant content / (C) glass fiber content] is 0.5 or less, and a molded article containing this polyolefin polymer composition.

Description

[Technical Field]

[0001] This invention relates to polyolefin-based polymer compositions and molded articles. [Background technology]

[0002] Polymer compositions such as resin compositions and elastomer compositions, which offer excellent moldability, are widely used in molded articles for vehicle parts such as automobiles, home appliances, and industrial products. On the other hand, these molded articles are required to be flame-retardant from the standpoint of safety and reliability. In particular, in recent years, electric vehicles (EVs), plug-in hybrid vehicles (PHVs), induction heating (IH) systems in home appliances, and miniaturization and performance improvements in industrial products have been rapidly progressing, requiring high levels of flame retardancy. For example, various products equipped with or incorporating lithium-ion batteries, especially components and peripheral parts that make up high-performance (high-capacity) batteries installed in EVs and PHVs, require a high degree of flame retardancy. As a polymer composition exhibiting high flame retardancy, for example, Patent Document 1 describes a polypropylene resin composition characterized by containing a polypropylene resin (A) having a long-chain branched structure having specific properties (X), a filler (B), a halogen-based flame retardant (C) having a melting point of 250°C or higher, and a flame retardant aid (E), and satisfying specific conditions (a). According to Patent Document 1, the above-mentioned polypropylene resin composition exhibits extremely high flame retardancy, which was difficult to achieve with conventional flame-retardant polypropylene resin compositions containing halogen-based flame retardants and antimony compounds, and can also impart mechanical properties (especially rigidity) and moldability. [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2015-078276 [Overview of the Initiative] [Problems that the invention aims to solve]

[0004] Incidentally, with the rapid progress in the development and practical application of EVs and PHVs, the batteries installed in them are becoming increasingly high-capacity and high-performance in terms of charging capabilities. However, high-performance batteries carry the risk of serious accidents such as abnormal heat generation and thermal runaway, which can lead to fire and explosion, and serious accidents due to thermal runaway have actually occurred. Therefore, technologies to improve the safety performance of batteries are being considered, and in 2023, the UL2596 standard: Test methods for thermal and mechanical performance of battery enclosure materials (2nd edition) was published, which includes a thermal runaway (BETR) test for battery enclosure materials. As mentioned above, this standard and test are designed to prevent serious accidents due to thermal runaway, etc., taking into account recent development trends and improvements in safety performance, and evaluate a high level of explosion resistance (flame retardancy). However, the UL2596 standard was established only recently, and measures to address it are still in their early stages and not yet fully implemented.

[0005] The present invention aims to provide a polyolefin polymer composition that maintains excellent moldability while meeting the explosion resistance performance requirements of the UL2596 BETR test, and a molded article containing the same. [Means for solving the problem]

[0006] The inventors of the present invention diligently conducted research to solve the above problems and found that in a polymer composition containing (A) a polyolefin polymer and (B) a flame retardant, by using (C) glass fibers in combination with these two components, and setting the mass ratio of the content of (B) flame retardant to the content of (C) glass fibers [(B) flame retardant content / (C) glass fiber content] to 0.5 or less, it is possible to obtain a predetermined molded product using various molding methods while also satisfying the explosion resistance performance in the BETR test of the UL2596 standard. The present invention was completed after further research based on these findings.

[0007] In other words, the objectives of the present invention were achieved by the following means. [1] (A) a polyolefin polymer, (B) a flame retardant, and (C) glass fiber, A polyolefin polymer composition in which the mass ratio of the content of the flame retardant (B) to the content of the glass fiber (C) [content of flame retardant (B) / content of glass fiber (C)] is 0.5 or less. [2] The polyolefin polymer composition according to [1], wherein the mass ratio [(B) content of flame retardant / (C) content of glass fiber] is 0.35 or less. [3] The polyolefin polymer composition according to [1] or [2], wherein the mass ratio [(B) content of flame retardant / (C) content of glass fiber] is 0.20 or more. [4] The polyolefin polymer composition according to any one of [1] to [3], wherein the (A) polyolefin polymer comprises a (A1-P) polypropylene polymer. [5] The polyolefin polymer composition according to any one of [1] to [4], wherein the flame retardant (B) contains a phosphorus-containing flame retardant. [6] The polyolefin polymer composition according to any one of [1] to [5], wherein the (C) glass fibers include short fibers. [7] The polyolefin polymer composition according to any one of [1] to [6], wherein the (A) polyolefin polymer comprises (A2) an acid-modified polyolefin polymer. [8] When the total content of (A) polyolefin polymer, (B) flame retardant and (C) glass fiber is 100% by mass, The content of the aforementioned (A) polyolefin polymer is 20 to 49% by mass, The content of the flame retardant (B) is 10 to 18% by mass, The polyolefin polymer composition according to any one of [1] to [7], wherein the content of (C) glass fibers is 41% by mass or more. [9] When the total content of the (A) polyolefin polymer, the (B) flame retardant, and the (C) glass fiber is 100% by mass, the content of the (A1-P) polypropylene polymer is 25 to 42% by mass. The polyolefin polymer composition according to any one of [4] to [8].

[10] When the total content of the (A) polyolefin polymer, the (B) flame retardant, and the (C) glass fiber is 100% by mass, the content of the (A2) acid-modified polyolefin polymer is 0.1 to 5.0% by mass. The polyolefin polymer composition according to any one of [7] to [9].

[11] It shows self-extinguishing properties corresponding to the V-0 judgment criterion in the vertical burning test defined in UL94 when it is a test piece with a thickness of 3 mm. The polyolefin polymer composition according to any one of [1] to

[10] .

[12] A molded body containing the polyolefin polymer composition according to any one of [1] to

[11] above.

[13] The molded body according to

[12] , which is an injection molded body.

[14] The molded body according to

[12] or

[13] , having a thickness of less than 10 mm.

[15] It shows self-extinguishing properties corresponding to the V-0 judgment criterion in the vertical burning test defined in UL94 when it is a test piece with a thickness of 3 mm. The molded body according to any one of

[12] to

[14] .

[16] The molded body according to any one of

[12] to

[15] , which is used for battery parts or their peripheral parts.

Advantages of the Invention

[0008] The present invention can provide a polyolefin polymer composition that satisfies the explosion resistance performance in the BETR test of UL2596 standard while maintaining excellent moldability, and a molded body containing the same.

Modes for Carrying Out the Invention

[0010] [[Explanation of Terms]] In describing the present invention, we will first explain the terms commonly used. In the present invention and this specification, "monomer unit" means a monomer-derived constituent unit (also called a structural unit or residue) contained in a polymer obtained by polymerizing monomers. In the present invention and this specification, "α-olefin" means an olefin having a carbon-carbon double bond at its terminal (α-position). In the present invention and this specification, the bonding mode (arrangement of constituent units) of two or more constituent units in a copolymer that becomes a resin or elastomer is not particularly limited, and unless otherwise specified, any bonding mode such as random bonding (random copolymer), block bonding (block copolymer), alternating bonding (alternating copolymer), or graft bonding (graft copolymer) may be used.

[0011] In the present invention and this specification, unless otherwise specified, "%" means mass percent and "parts" means "parts by mass".

[0012] In the present invention and this specification, when describing content, physical properties, etc., by indicating numerical ranges, if the upper and lower limits of the numerical range are described separately, either upper or lower limit can be appropriately combined to form a specific numerical range. On the other hand, when multiple numerical ranges represented by "~" are set and described, the upper and lower limits forming the numerical range are not limited to the specific combinations written before and after "~" as a specific numerical range, but can be a numerical range formed by appropriately combining the upper and lower limits of each numerical range. In the present invention and this specification, a numerical range represented by "~" means a range that includes the numbers written before and after "~" as the lower and upper limits.

[0013] In the present invention and this specification, "melt flow rate (MFR)" means "melt mass flow rate," and unless otherwise specified, it is the melt flow rate (unit: g / 10 min) measured in accordance with JIS K 7210-1:2014 and JIS K 7210-2:2014 under conditions of a temperature of 230°C and a load of 2.16 kgf.

[0014] In the present invention and this specification, "intrinsic viscosity (unit: dL / g)" is a value measured at a temperature of 135°C using tetralin as a solvent by the following method. Using an Ubbelohde viscometer, the reduced viscosity is measured at multiple concentrations, the reduced viscosity is plotted against the concentration, and the intrinsic viscosity is determined by the "extrapolation method," which involves extrapolating the concentration to zero. More specifically, the intrinsic viscosity is determined using the method described on page 491 of "Polymer Solutions, Polymer Experiments 11" (Kyoritsu Shuppansha, 1982), by measuring the reduced viscosity at three points with concentrations of 0.1 g / dL, 0.2 g / dL, and 0.5 g / dL, plotting the reduced viscosity against the concentration, and extrapolating the concentration to zero.

[0015] [[Polyolefin polymer composition]] The polyolefin polymer composition of the present invention contains (A) a polyolefin polymer, (B) a flame retardant, and (C) glass fibers. The mass ratio of the flame retardant content (B) to the glass fiber content [(B) flame retardant content / (C) glass fiber content] is 0.5 or less. This polyolefin polymer composition exhibits excellent moldability. Furthermore, the polyolefin polymer composition of the present invention meets the blast resistance performance requirements of the UL2596 BETR test. In the present invention, meeting the blast resistance performance requirements of the UL2596 BETR test means that after performing the BETR test on a plate-shaped test piece with a thickness of 1.0 mm or more and less than 10 mm up to 5 minutes after the occurrence of thermal runaway, the plate-shaped test piece shows no spread of fire, destruction, etc., and is in a state where there is no visible external damage, such as no holes. Therefore, the polyolefin polymer composition of the present invention can meet the blast resistance performance requirements of the BETR test while maintaining excellent moldability, and can provide a high level of safety and reliability to parts having its molded body. Furthermore, the polyolefin polymer composition of the invention preferably exhibits high thermal insulation properties, with a large temperature difference between the inner and outer surface temperatures of the plate-shaped test specimen in the BETR test according to the UL2596 standard. In the present invention, the above temperature difference is not particularly limited, but is preferably 110°C or higher, and more preferably 130 to 500°C. Moreover, the polyolefin polymer composition of the present invention preferably has the properties described later, exhibiting high rigidity and high flame retardancy (self-extinguishing properties). Therefore, the above-mentioned preferred polyolefin polymer composition of the present invention can provide even higher safety and reliability to parts having its molded articles.

[0016] First, the components contained in the polyolefin polymer composition of the present invention will be described. Each component contained in the polyolefin polymer composition of the present invention may be one or two or more.

[0017] [(A) Polyolefin polymers] (A) Polyolefin polymers are polymers obtained by homopolymerizing or copolymerizing α-olefins, and preferably contain units derived from α-olefins (also called "α-olefin units") in amounts greater than 50% by mass relative to the total constituent units of the polymer (100% by mass). (A) The α-olefin units in polyolefin polymers are usually 100% by mass or less. (A) The polyolefin polymer includes an acid-unmodified olefin polymer that has not been modified with acid (sometimes simply called (A1) polyolefin polymer) and an acid-modified polyolefin polymer (A2) obtained by modifying the (A1) polyolefin polymer with acid. (A) The polyolefin polymer preferably contains the (A1) polyolefin polymer or the (A2) acid-modified polyolefin polymer in terms of moldability, explosion resistance, and furthermore, heat insulation, high flame retardancy, and bending rigidity, and more preferably contains the (A1) polyolefin polymer and the (A2) acid-modified polyolefin polymer.

[0018] <(A1) Polyolefin polymer> (A1) The α-olefins that form the polyolefin polymer are not particularly limited, and examples include α-olefins having 2 to 10 carbon atoms (hereinafter also referred to as "carbon number"). The chain structure of the α-olefin is not particularly limited, and may be a linear structure, a branched chain structure, or a cyclic structure. Examples of α-olefins having 2 to 10 carbon atoms include ethylene, propylene, 1-butene, 4-methyl-1-pentene, 1-hexene, 1-octene, and 1-decene.

[0019] (A1) Polyolefin polymers may have units derived from polymerizable compounds other than α-olefins. The polymerizable compounds can be any compounds copolymerizable with α-olefins, and examples include vinyl ester compounds (e.g., vinyl acetate, vinyl propionate), (meth)acrylic monomers (e.g., (meth)acrylic acid compounds, alkyl (meth)acrylate compounds, vinyl cyanide compounds such as (meth)acrylonitrile), diene compounds (e.g., butadiene), unsaturated polycarboxylic acids or their acid anhydrides (e.g., maleic acid, itaconic acid, citraconic acid or their acid anhydrides), and imide compounds (e.g., maleimide, N-substituted maleimides such as N-alkylmaleimide).

[0020] Such (A1) polyolefin polymers are not particularly limited and include polyethylene polymers and polypropylene polymers (A1-P). Examples of polyethylene polymers include high-density polyethylene, low-density polyethylene, linear low-density polyethylene, and ultra-low-density polyethylene.

[0021] In the present invention, (A) the weight-average molecular weight Mw of the polyolefin polymer in terms of polystyrene is typically 1.0 × 10⁻⁶, from the viewpoint of improving the appearance and elongation properties of the molded article. 5 ~1.0×10 6 Preferably 5.0 × 10 5 ~1.0×10 6 That is the case.

[0022] From the viewpoint of improving moldability and mechanical properties, polyolefin polymers are preferably characterized by a molecular weight distribution (Mw / Mn) of 10 or less, and more preferably between 3 and 8. Here, Mw represents the weight-average molecular weight, and Mn represents the number-average molecular weight. The weight-average molecular weight, number-average molecular weight, and molecular weight distribution can be measured by gel permeation chromatography (GPC) and calculated in polystyrene equivalents.

[0023] Polyolefin polymers, especially polypropylene polymers, are preferred from the viewpoint of the rigidity of molded articles, 13 The isotactic pentad fraction (also called the [mmmm] fraction), measured by 13C-NMR, is preferably 0.97 or higher, and more preferably 0.98 or higher. The closer the isotactic pentad fraction is to 1, the higher the stereoregularity of the molecular structure and the higher the crystallinity. When the polyolefin polymer is a copolymer, the isotactic pentad fraction can be measured for the chain of propylene units in the copolymer.

[0024] From the viewpoint of improving the processability of the polyolefin polymer composition of the present invention in molding, the melt flow rate (MFR) of the polyolefin polymer, measured under conditions of a temperature of 230°C and a load of 2.16 kgf, is preferably 0.1 g / 10 min or more, more preferably 0.5 g / 10 min or more, while preferably 500 g / 10 min or less, more preferably 400 g / 10 min or less, and even more preferably 0.1 g / 10 min to 500 g / 10 min.

[0025] (Polyethylene polymer) A polyethylene polymer is a polymer that contains 50% by mass or more of ethylene-derived constituent units (also called "ethylene units") relative to the total constituent units of the polymer (100% by mass). The ethylene unit content in polyethylene polymers is usually 100% by mass or less. When a polyethylene polymer contains propylene-derived constituent units (also called "propylene units"), the propylene unit content is usually 50% by mass or less. In this invention, when referring to a polyethylene polymer, unless otherwise specified, it does not include acid-modified polyethylene polymers. Examples of polyethylene polymers include ethylene homopolymers, copolymers of ethylene and α-olefins, and copolymers of ethylene and α-olefins substituted with alicyclic compounds.

[0026] As an ethylene homopolymer, it is formed by high-pressure radical polymerization using a radical initiator, in which repeating ethylene units are randomly linked in a branched structure, with a density of 910-935 kg / m³. 3 High-pressure low-density polyethylene (LDPE) is a preferred example.

[0027] Examples of copolymers of ethylene and α-olefins include crystalline linear low-density polyethylene (LLDPE) and elastomers of copolymers of ethylene and α-olefins that have low crystallinity and rubbery elastic properties.

[0028] The density of linear low-density polyethylene is 900-940 kg / m³. 3 This can be achieved, and the density of the ethylene-α-olefin copolymer elastomer is 860-900 kg / m³. 3 It can be done this way.

[0029] Examples of α-olefins copolymerized with ethylene are not particularly limited, but include, for example, α-olefins having 3 to 10 carbon atoms, with α-olefins having 4 to 10 carbon atoms being preferred. Examples of α-olefins having 3 to 10 carbon atoms include propylene, 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 1-octene, 1-decene, and 3-methyl-1-butene, while preferred α-olefins having 4 to 10 carbon atoms are 1-butene, 1-hexene, or 1-octene.

[0030] Examples of α-olefins substituted with the above-mentioned alicyclic compounds include vinylcyclopropane, vinylcyclobutane, and vinylcyclohexane.

[0031] The content of α-olefin-derived structural units in the total structural units (100% by mass) of the polyethylene polymer is not particularly limited, and can be, for example, 4.0 to 20% by mass.

[0032] Examples of copolymers of ethylene and α-olefins include ethylene-1-butene copolymer, ethylene-1-hexene copolymer, ethylene-1-octene copolymer, ethylene-1-decene copolymer, and ethylene-(3-methyl-1-butene) copolymer.

[0033] The melt flow rate (MFR) of the polyethylene polymer, measured at a temperature of 190°C and under a load of 2.16 kg, is not particularly limited, but in terms of the MFR and moldability of the polyolefin polymer composition of the present invention, it can be 0.5 to 50 g / 10 min, preferably 1 to 30 g / 10 min, and more preferably 1 to 20 g / 10 min.

[0034] The polyethylene polymer contained in the polyolefin polymer composition of the present invention may be one type or two or more types. When two or more polyethylene polymers are contained, an ethylene homopolymer and a copolymer of ethylene and α-olefin may be included.

[0035] Polyethylene polymers can be produced using known polymerization catalysts and known polymerization methods. Examples of polymerization catalysts include homogeneous catalyst systems, such as metallocene catalysts, Ziegler-type catalyst systems, and Ziegler-Natta-type catalyst systems. Examples of homogeneous catalyst systems include catalyst systems consisting of a transition metal compound of Group 4 of the periodic table having a cyclopentadienyl ring and an alkylaluminoxane, or catalyst systems consisting of a transition metal compound of Group 4 of the periodic table having a cyclopentadienyl ring, a compound that reacts with it to form an ionic complex, and an organoaluminum compound, or catalyst systems in which catalyst components such as a transition metal compound of Group 4 of the periodic table having a cyclopentadienyl ring, a compound that forms an ionic complex, and an organoaluminum compound are supported and modified on inorganic particles such as silica and clay minerals, and also prepolymerization catalyst systems prepared by prepolymerizing ethylene or α-olefins in the presence of the above catalyst systems. Furthermore, high-pressure low-density polyethylene (LDPE) can be produced using a radical initiator as a polymerization catalyst.

[0036] ((A1-P) Polypropylene polymer) (A1-P) Polypropylene polymers are polymers that contain more than 50% by mass of propylene units relative to the total constituent units (100% by mass). The propylene unit content in polypropylene polymers is usually 100% by mass or less. If these polypropylene polymers contain ethylene units, the ethylene unit content is usually less than 50% by mass. In this invention, when referring to polypropylene polymers, unless otherwise specified, it means that acid-modified polypropylene polymers are not included.

[0037] Examples of polypropylene polymers include propylene homopolymers and copolymers obtained by polymerizing propylene with one or more other monomers copolymerizable with propylene in any ratio. The copolymer may be a random copolymer or a block copolymer.

[0038] Other monomers that can copolymerize with propylene are not particularly limited, but include, for example, α-olefins other than propylene, specifically ethylene and α-olefins having 4 or more carbon atoms. The number of carbon atoms in the α-olefin may be 12 or less. α-olefins having four or more carbon atoms may be linear or branched. α-olefins having four or more carbon atoms may also be cyclic α-olefins, such as vinylcyclopropane, vinylcyclobutane, and vinylcyclohexane. Examples of α-olefins other than propylene include ethylene, 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 1-octene, and 1-decene. Among these, ethylene, 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 1-octene, and 1-decene are preferred, and ethylene, 1-butene, 1-hexene, and 1-octene are more preferred.

[0039] The polyolefin polymer composition of the present invention may contain one polypropylene polymer, or it may contain two or more polypropylene polymers in any combination of proportions.

[0040] Examples of single polypropylene polymers include propylene homopolymers and random copolymers of propylene with the other monomers mentioned above (hereinafter also referred to as polypropylene random copolymers). Examples of combinations of two or more polypropylene polymers include combinations of two or more propylene homopolymers with different weight-average molecular weights, combinations of propylene homopolymers and polypropylene random copolymers, and combinations of polymer (I) and polymer (II) described below.

[0041] The polyolefin polymer composition may contain a heterophagic propylene polymerization material as the polypropylene polymer. Here, "heterophagic propylene polymerization material" means a material that contains two or more polypropylene polymers, in which the two or more polypropylene polymers are miscible and form separate phases from each other. Examples of heterophagic propylene polymerization materials include the following combinations of polymer (I) and polymer (II). Here, polymer (I) is a polymer having propylene units in an amount greater than 80% by mass and less than or equal to 100% by mass relative to the total amount of constituent units, and may be a propylene homopolymer or a copolymer of propylene and the above-mentioned other monomers. Polymer (II) is a copolymer of propylene units and at least one monomer unit selected from the group consisting of ethylene units and α-olefin units having 4 or more carbon atoms. Polymer (I) and polymer (II) may each be a single polymer or a combination of two or more polymers.

[0042] The polypropylene polymer is preferably one or more selected from the group consisting of propylene homopolymers and heterophagic propylene polymerization materials, and more preferably a propylene homopolymer, from the viewpoint of moldability, explosion resistance, as well as heat insulation, bending rigidity, flame retardancy, and impact resistance.

[0043] Polypropylene polymers can be produced, for example, by the following polymerization method using a polymerization catalyst. Examples of polymerization catalysts include Ziegler-type catalyst systems, Ziegler-Natta-type catalyst systems, catalyst systems containing transition metal compounds of Group 4 of the periodic table having a cyclopentadienyl ring and alkylaluminoxanes, catalyst systems containing transition metal compounds of Group 4 of the periodic table having a cyclopentadienyl ring, compounds that react with them to form ionic complexes, and organoaluminum compounds, and catalyst systems in which catalyst components (e.g., transition metal compounds of Group 4 of the periodic table having a cyclopentadienyl ring, compounds that form ionic complexes, organoaluminum compounds, etc.) are supported on inorganic particles (e.g., silica, clay minerals, etc.) and modified. Alternatively, prepolymerization catalysts prepared by prepolymerizing monomers such as ethylene and α-olefins in the presence of such catalyst systems may be used. Examples of Ziegler-Natta-type catalyst systems include catalyst systems that use a combination of titanium-containing solid transition metal components and organometallic components.

[0044] Examples of such catalyst systems include those 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, and Japanese Patent Publication No. 2004-182981. In this specification, the contents described in the above patent documents may be referenced as appropriate, and their contents will be incorporated as part of this specification.

[0045] Polymerization methods include bulk polymerization, solution polymerization (liquid-phase 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.

[0046] When carrying out the polymerization method, the polymerization method can be a batch method, a continuous method, or a combination thereof. The polymerization method may also be a multi-stage method using multiple polymerization reactors connected in series.

[0047] Various conditions in the polymerization method (polymerization temperature, polymerization pressure, monomer concentration, catalyst input amount, polymerization time, etc.) can be appropriately determined according to the target polypropylene polymer.

[0048] In the production of polypropylene polymers, in order to remove residual solvents contained in the obtained polypropylene polymer and ultra-low molecular weight oligomers produced as by-products during production, the obtained polypropylene polymer may be held at a temperature at which the residual solvents and other impurities such as oligomers can volatilize, and at a temperature lower than the melting temperature of the polypropylene polymer. Examples of methods for removing residual solvents and other impurities such as oligomers include the methods described in Japanese Patent Publication No. 55-75410 and Japanese Patent No. 2565753, and the contents described in these patent documents may be appropriately referenced in this specification, and their contents will be incorporated as part of this specification.

[0049] - Propylene homopolymer - From the viewpoint of improving the fluidity of the polyolefin polymer composition of the present invention during melting and the toughness of the molded article containing the polyolefin polymer composition, the propylene homopolymer preferably has an intrinsic viscosity [η] of 0.1 to 5 dL / g, more preferably 0.5 to 4 dL / g, and even more preferably 0.6 to 3 dL / g.

[0050] From the viewpoint of improving the fluidity of the polyolefin polymer composition of the present invention during melting and the toughness of the molded article containing the polyolefin polymer composition of the present invention, the propylene homopolymer preferably has a molecular weight distribution Mw / Mn of 2 or more and less than 10, more preferably 3 to 8, and even more preferably 3 to 6. Here, Mw represents the weight-average molecular weight, and Mn represents the number-average molecular weight. The molecular weight distribution can be measured by gel permeation chromatography (also known as GPC).

[0051] - Polypropylene-based random copolymer - Examples of polypropylene-based random copolymers include random copolymers containing propylene units and ethylene units (hereinafter also referred to as "random copolymer (1)"), random copolymers containing propylene units and units derived from α-olefins having 4 or more carbon atoms (hereinafter also referred to as "olefin units") (hereinafter also referred to as "random polymer (2)"), and random copolymers containing propylene units, ethylene units, and olefin units (hereinafter also referred to as "random polymer (3)").

[0052] The α-olefins having 4 or more carbon atoms that can constitute a polypropylene-based random copolymer may be linear, branched, or cyclic olefins. Preferably, the α-olefin has 4 to 10 carbon atoms. Examples of α-olefins having 4 to 10 carbon atoms include 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 1-octene, and 1-decene, with 1-butene, 1-hexene, and 1-octene being preferred. Examples of cyclic olefins include vinylcyclopropane and vinylcyclobutane.

[0053] Examples of random copolymers (2) include propylene-1-butene random copolymer, propylene-1-hexene random copolymer, propylene-1-octene random copolymer, and propylene-1-decene random copolymer.

[0054] Examples of random copolymers (3) include propylene-ethylene-1-butene copolymer, propylene-ethylene-1-hexene copolymer, propylene-ethylene-1-octene copolymer, and propylene-ethylene-1-decene copolymer.

[0055] The content of ethylene units in the random copolymer (1) is not particularly limited, but is preferably 0.1 to 40% by mass, more preferably 0.1 to 30% by mass, and even more preferably 2 to 15% by mass. The content of olefin units in the random copolymer (2) is not particularly limited, but is preferably 0.1 to 40% by mass, more preferably 0.1 to 30% by mass, and even more preferably 2 to 15% by mass. The total content of ethylene units and olefin units in the random copolymer (3) is not particularly limited, but is preferably 0.1 to 40% by mass, more preferably 0.1 to 30% by mass, and even more preferably 2 to 15% by mass.

[0056] The propylene unit content in these random copolymers (1) to (3) is not particularly limited, but is preferably 60 to 99.9% by mass, more preferably 70 to 99.9% by mass, and even more preferably 85 to 98% by mass.

[0057] From the viewpoint of improving the fluidity and processability of the polyolefin polymer composition of the present invention when melted, the propylene-based random copolymer has an intrinsic viscosity [η] that is usually less than 5 dL / g, 0.1 dL / g or more, preferably 0.5 dL / g or more, more preferably 0.7 dL / g or more and less than 4 dL / g, and even more preferably 0.8 dL / g or more and less than 3 dL / g.

[0058] - Heterophagic propylene polymerization materials - Polymer (I) is a polymer having propylene units in an amount greater than 80% by mass and less than or equal to 100% by mass relative to the total amount of constituent units, as described above. The total content of monomer units other than propylene units in polymer (I) is usually 0% by mass or more and less than 20% by mass, with the mass of polymer (I) being 100% by mass, and may be 0% by mass or 0.01% by mass or more.

[0059] Other monomer units besides propylene units that polymer (I) may have include ethylene units and α-olefin units having 4 or more carbon atoms. The α-olefin having 4 or more carbon atoms that can constitute polymer (I) may be a linear olefin, a branched olefin, or a cyclic olefin. The α-olefin is the same as the α-olefin having 4 or more carbon atoms in the polypropylene-based random copolymer described above, preferably an α-olefin having 4 to 10 carbon atoms, more preferably 1-butene, 1-hexene, 1-octene, and 1-decene, and even more preferably 1-butene.

[0060] Examples of polymers (I) include propylene homopolymer, 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.

[0061] Among these, the polymer (I) is preferably a propylene homopolymer, a propylene-ethylene copolymer, a propylene-1-butene copolymer, and a propylene-ethylene-1-butene copolymer, and from the viewpoint of rigidity of the molded article containing the polyolefin polymer composition of the present invention, a propylene homopolymer is particularly preferred.

[0062] Polymer (II), as described above, is a copolymer of a propylene unit and at least one other monomer unit selected from the group consisting of ethylene units and α-olefin units having 4 or more carbon atoms.

[0063] Polymer (II) is preferably a polymer having propylene units in an amount greater than 0% by mass and less than or equal to 90% by mass relative to the total mass of constituent units, and more preferably a polymer having propylene units greater than 0% by mass and less than or equal to 80% by mass. Polymer (II) may be a random copolymer or a block copolymer. The total content of ethylene units and α-olefin units having 4 or more carbon atoms in polymer (II) is preferably 20 to 80% by mass, and more preferably 20 to 60% by mass, relative to the total mass of all constituent units of polymer (II).

[0064] The α-olefins having 4 or more carbon atoms that can constitute polymer (II) are preferably α-olefins having 4 to 10 carbon atoms, and are the same as the α-olefins that can constitute polymer (I).

[0065] 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. Preferably, polymer (II) is propylene-ethylene copolymer, propylene-1-butene copolymer, and propylene-ethylene-1-butene copolymer, and more preferably propylene-ethylene copolymer.

[0066] The content of polymer (II) in the heterophagic propylene polymerization material is not particularly limited, but is preferably 1 to 50% by mass, more preferably 1 to 45% by mass, even more preferably 5 to 40% by mass, and particularly preferably 7 to 35% by mass, with the total mass of polymer (I) and polymer (II) being 100% by mass.

[0067] Examples of heterophagic propylene polymerization materials include the following polymer combinations in which polymer (I) is a propylene homopolymer. Combinations of propylene homopolymer and (propylene-ethylene) copolymer, combinations of propylene homopolymer and (propylene-ethylene-1-butene) copolymer, combinations of propylene homopolymer and (propylene-ethylene-1-hexene) copolymer, combinations of propylene homopolymer and (propylene-ethylene-1-octene) copolymer, combinations of propylene homopolymer and (propylene-1-butene) copolymer, combinations of propylene homopolymer and (propylene-1-hexene) copolymer, combinations of propylene homopolymer and (propylene-1-octene) copolymer, and combinations of propylene homopolymer and (propylene-1-decene) copolymer

[0068] Furthermore, examples of heterophagic propylene polymerization materials include the following combinations of polymers in which polymer (I) contains propylene units and other monomer units other than propylene units. Here, the type of polymer (I) is described first, followed by the type of polymer (II). A combination of (propylene-ethylene) copolymer and (propylene-ethylene) copolymer, a combination of (propylene-ethylene) copolymer and (propylene-ethylene-1-butene) copolymer, a combination of (propylene-ethylene) copolymer and (propylene-ethylene-1-hexene) copolymer, a combination of (propylene-ethylene) copolymer and (propylene-ethylene-1-octene) copolymer, a combination of (propylene-ethylene) copolymer and (propylene-ethylene-1-decene) copolymer, a combination of (propylene-ethylene) copolymer and Combinations with (propylene-1-butene) copolymer, combinations with (propylene-ethylene) copolymer and (propylene-1-hexene) copolymer, combinations with (propylene-ethylene) copolymer and (propylene-1-octene) copolymer, combinations with (propylene-ethylene) copolymer and (propylene-1-decene) copolymer, combinations with (propylene-1-butene) copolymer and (propylene-ethylene) copolymer, combinations with (propylene-1-butene) copolymer and (propylene-ethylene-1-butene) copolymer, (propylene A combination of (propylene-1-butene) copolymer and (propylene-ethylene-1-hexene) copolymer, a combination of (propylene-1-butene) copolymer and (propylene-ethylene-1-octene) copolymer, a combination of (propylene-1-butene) copolymer and (propylene-ethylene-1-decene) copolymer, a combination of (propylene-1-butene) copolymer and (propylene-1-butene) copolymer, a combination of (propylene-1-butene) copolymer and (propylene-1-hexene) copolymer, a combination of (propylene-1-butene) copolymer and (propylene-1-hexene) copolymer Combinations with pyrene-1-octene copolymer, combinations of (propylene-1-butene) copolymer and (propylene-1-decene) copolymer, combinations of (propylene-1-hexene) copolymer and (propylene-1-hexene) copolymer, combinations of (propylene-1-hexene) copolymer and (propylene-1-octene) copolymer, combinations of (propylene-1-hexene) copolymer and (propylene-1-decene) copolymer, combinations of (propylene-1-octene) copolymer and (propylene-1-octene) copolymer, andA combination of (propylene-1-octene) copolymer and (propylene-1-decene) copolymer,

[0069] The heterophagic propylene polymerization materials that can be included in the polyolefin polymer composition of the present invention are preferably a combination of propylene homopolymer and (propylene-ethylene) copolymer, a combination of propylene homopolymer and (propylene-ethylene-1-butene) copolymer, a combination of (propylene-ethylene) copolymer and (propylene-ethylene) copolymer, a combination of (propylene-ethylene) copolymer and (propylene-ethylene-1-butene) copolymer, and a combination of (propylene-1-butene) copolymer and (propylene-1-butene) copolymer, and more preferably a combination of propylene homopolymer and (propylene-ethylene) copolymer.

[0070] Heterophasic propylene polymerization materials can be produced by multi-stage polymerization, which includes a polymerization step to produce polymer (I) and a polymerization step to produce polymer (II) in the presence of polymer (I) produced in the preceding step. Polymerization can be carried out using the catalyst system exemplified as a catalyst usable for the production of the above polypropylene polymer.

[0071] The intrinsic viscosity of polymer (I) (hereinafter referred to as [η]I) is preferably 0.1 to 5 dL / g, more preferably 0.5 to 4 dL / g, and even more preferably 0.6 to 3 dL / g.

[0072] The intrinsic viscosity of polymer (II) (hereinafter referred to as [η]II) is preferably 1 to 10 dL / g, more preferably 1.5 to 9 dL / g, and even more preferably 2 to 8 dL / g.

[0073] Furthermore, the ratio of [η]II to [η]I ([η]II / [η]I) is preferably 1 to 20, and more preferably 1 to 10.

[0074] When a polypropylene polymer is a polymer material consisting of polymer (I) and polymer (II) formed by multi-stage polymerization, the intrinsic viscosity of polymer (I) formed in the first stage of polymerization can be partially withdrawn from the polymerization tank and determined. The intrinsic viscosity of the polymer material finally obtained by multi-stage polymerization (hereinafter referred to as [η]Total) can then be determined. Using these intrinsic viscosity values ​​and the content of each polymer, the intrinsic viscosity of the polymer formed in the second stage of polymerization can be calculated.

[0075] Furthermore, if the polymer material consisting of polymer (I) and polymer (II) is manufactured by a method in which polymer (I) is obtained in a preceding polymerization step and polymer (II) is obtained in a subsequent polymerization step, the procedure for measuring and calculating the respective contents of polymer (I) and polymer (II), and the intrinsic viscosity ([η]Total, [η]I, [η]II) is as follows.

[0076] The intrinsic viscosity [η]II of polymer (II) can be calculated using the following formula, based on the intrinsic viscosity ([η]I) of polymer (I) obtained in the preceding polymerization step, the intrinsic viscosity ([η]Total) of the final polymer after the subsequent polymerization step (i.e., the polymerization material consisting of polymer (I) and polymer (II)) measured by the method described above, and the content of polymer (II) in the final polymer. [η]II=([η]Total-[η]I×XI) / XII In the above formula, [η] Total: Intrinsic viscosity of the final polymer (unit: dL / g) [η]I: Intrinsic viscosity of polymer (I) (unit: dL / g) XI: Mass ratio of polymer (I) to the final polymer XII: Mass ratio of polymer (II) to final polymer Furthermore, XI and XII can be determined from the mass balance during polymerization.

[0077] The mass ratio XII of polymer (II) to the final polymer may be calculated using the following formula, based on the respective heats of fusion of polymer (I) and the final polymer. XII = 1 - (ΔHf)T / (ΔHf)P In the above formula, (ΔHf)T: Heat of fusion of the final polymer (polymer (I) and polymer (II)) (unit: cal / g) (ΔHf)P: Heat of fusion of polymer (I) (unit: cal / g)

[0078] Also, the molecular weight distribution (Mw / Mn) of the above polymer (I) measured by GPC is preferably 1 or more and less than 10, more preferably 2 or more and less than 7, and even more preferably 3 or more and less than 5.

[0079] In the present invention and this specification, the "polyolefin-based polymer" may be, for example, a polymer containing carbon 14 ( 14 C) as the carbon element constituting the main carbon chain, or a polymer containing a carbon element (monomer) recycled (mechanically recycled).

[0080] The concentration of carbon 14 ( 14 C) contained in the polyolefin-based polymer is determined as pMC (percentage of modern carbon: unit %) by the AMS (Accelerator mass spectrometry) method specified in ISO 16620-2:2019. Since carbon dioxide in the atmosphere contains carbon 14 ( 14 C) at a certain ratio, plants that grow by incorporating carbon dioxide in the atmosphere, such as corn and trees, contain 14 C. On the other hand, it is also known that fossil resources such as petroleum, which are considered to have been stored underground for a long time, contain almost no carbon 14 ( 14 C). Therefore, by using plant-derived substances as raw materials for monomers used in the production of polyolefin-based polymers, carbon 14 ( 14 C) can be contained in the constituent elements of the polyolefin-based polymer.

[0081] (A) In the production of polyolefin polymers, monomers derived from fossil resources (hereinafter referred to as "fossil resource-derived monomers"; for example, fossil resource-derived ethylene, fossil resource-derived propylene, fossil resource-derived 1-butene, fossil resource-derived 1-hexene, etc.), monomers derived from plants (hereinafter referred to as "plant-derived monomers"; for example, plant-derived ethylene, plant-derived propylene, plant-derived 1-butene, plant-derived 1-hexene, etc.), monomers obtained by chemical recycling (hereinafter referred to as "chemically recycled monomers"; for example, chemically recycled ethylene, chemically recycled propylene, chemically recycled 1-butene, chemically recycled 1-hexene, etc.) can be used, and two or more of these can be used in combination. The specific combinations of monomers that can be used in the production of polyolefin polymers are not particularly limited, and include combinations of two or more monomers appropriately selected from fossil resource-derived monomers, plant-derived monomers, and chemically recycled monomers. For example, combinations of fossil resource-derived monomers and plant-derived monomers, combinations of fossil resource-derived monomers and chemically recycled monomers, combinations of plant-derived monomers and chemically recycled monomers, and combinations of fossil resource-derived monomers, plant-derived monomers, and chemically recycled monomers are possible.

[0082] Specific combinations of monomers that can be used in the production of polyolefin polymers include, for example, the following combinations (E1) to (E3) for polyethylene polymers, and the following combinations (P1) to (P3) for (A1-P) polypropylene polymers. (E1) A combination of two or three types of ethylene selected from fossil fuel-derived ethylene, plant-derived ethylene, and chemically recycled ethylene. (E2) A combination of one or more types of ethylene selected from fossil resource-derived ethylene, plant-derived ethylene, and chemically recycled ethylene, and one or more types of 1-butene selected from fossil resource-derived 1-butene, plant-derived 1-butene, and chemically recycled 1-butene. (E3) Combinations of one or more ethylenes selected from fossil resource-derived ethylene, plant-derived ethylene, and chemically recycled ethylene, and one or more 1-hexenes selected from fossil resource-derived 1-hexene, plant-derived 1-hexene, and chemically recycled 1-hexene. (P1) A combination of two or three propylenes selected from fossil fuel-derived propylene, plant-derived propylene, and chemically recycled propylene. (P2) A combination of one or more propylenes selected from fossil resource-derived propylene, plant-derived propylene, and chemically recycled propylene, and one or more ethylenes selected from fossil resource-derived ethylene, plant-derived ethylene, and chemically recycled ethylene. (P3) A combination of one or more propylenes selected from fossil resource-derived propylene, plant-derived propylene, and chemically recycled propylene, and one or more 1-butenes selected from fossil resource-derived 1-butene, plant-derived 1-butene, and chemically recycled 1-butene.

[0083] Fossil fuel-derived monomers are derived from carbon compounds that make up fossil resources (underground resources) such as petroleum, coal, and natural gas, and are generally carbon-14. 14 It contains almost no C). Methods for producing monomers derived from fossil resources include known methods, such as cracking of petroleum-derived naphtha and ethane, and dehydrogenation of ethane and propane to produce olefins.

[0084] As described above, the (A) polyolefin polymer used in the present invention may contain one or more plant-derived monomers (also called biomass-derived monomers). Plant-derived monomers are derived from carbon that circulates on the Earth's surface as plants and animals, and are monomers obtained from any renewable natural raw materials and their residues, such as fungi, yeasts, algae, and bacteria, which are plant-derived or animal-derived. Plant-derived monomers generally contain a certain proportion of carbon, for example, 10 -12 To a certain extent, carbon-14 ( 14It contains C). The monomers of the same type that make up the polymer may consist only of biomass-derived monomers, or it may contain both biomass-derived monomers and fossil resource-derived monomers. Plant-derived monomers can be obtained by conventionally known methods. Methods for producing plant-derived monomers include known methods such as cracking of bionaphtha, vegetable oil, and animal oil; dehydrogenation of biopropane; separation of alcohol from fermented products such as sugars extracted from plant raw materials such as sugarcane and corn, followed by a dehydration reaction (see, for example, Japanese Patent Publication No. 2010-511634, Japanese Patent Publication No. 2011-506628, and Japanese Patent Publication No. 2013-503647); and a metathesis reaction of ethylene obtained from plant-derived ethanol with n-butene (see, for example, International Publication No. 2007 / 055361). It is preferable from the viewpoint of reducing environmental impact that the (A) polyolefin polymer used in the present invention contains plant-derived monomers. If the polymer production conditions such as polymerization catalyst and polymerization temperature are equivalent, even if the raw material olefin contains biomass-derived olefins, 14 10 C isotopes -12 Aside from the small proportions it contains, its molecular structure is equivalent to that of polyolefin polymers composed of fossil fuel-derived monomers. Therefore, its performance is considered to be the same.

[0085] Furthermore, as described above, the (A) polyolefin polymer used in the present invention may contain one or more chemically recycled monomers. The propylene constituting the polymer may consist solely of chemically recycled monomers, or it may contain chemically recycled monomers and fossil resource-derived monomers and / or biomass-derived monomers. Chemical recycled monomers are derived from carbon generated by the decomposition and combustion of waste, and their carbon-14 ( 14C) The content varies depending on the waste. Chemical recycled monomers can be obtained by conventionally known methods. Methods for producing chemical recycled monomers include known methods, such as the thermal decomposition of waste plastics (see, for example, Japanese Patent Publication No. 2017-512246), the cracking of waste vegetable oils, waste animal oils, etc. (see, for example, Japanese Patent Publication No. 2018-522087), and the gasification, alcohol conversion, and dehydration reaction of waste such as food waste, biomass waste, food waste, waste oil, waste wood, paper waste, and waste plastics (see, for example, Japanese Patent Publication No. 2019-167424, International Publication No. 2021 / 006245). It is preferable from the viewpoint of reducing environmental impact (mainly waste reduction) that the (A) polyolefin polymer used in the present invention contains chemically recycled monomers. Even if the raw material monomers include chemically recycled monomers, as mentioned above, chemically recycled monomers are monomers obtained by depolymerizing polymers such as waste plastics, thermally decomposing them, etc., back to monomer units such as propylene, as well as monomers produced using such monomers as raw materials. Therefore, if the polymer production conditions such as polymerization catalysts, polymerization processes, and polymerization temperatures are the same, the molecular structure is equivalent to that of polyolefin polymers made from fossil resource-derived monomers. Consequently, the performance is also considered to be the same.

[0086] When using two or more monomers derived from fossil resources, plant-derived monomers, and chemically recycled monomers in the production of polyolefin polymers, the monomers produced individually can be combined as appropriate, and specific combinations of monomers are as described above. Furthermore, in the raw materials and intermediates of the monomer (olefin) production process, mixtures of fossil resource-derived compounds and plant-derived compounds, mixtures of fossil resource-derived compounds and chemically recycled compounds, mixtures of plant-derived compounds and chemically recycled compounds, and mixtures of fossil resource-derived compounds, plant-derived compounds, and chemically recycled compounds can be used instead of the above-mentioned combinations of monomers.

[0087] Carbon-14 ( 14 As the polyethylene polymer containing C), commercially available polyethylene polymers can be used. Examples include the "I'M GREEN" series from Braskem, the "TRUCIRCLE" series from SABIC, and the "CirculenRenew" series from LyondellBasell.

[0088] Carbon-14 ( 14 As the polypropylene polymer containing C), commercially available polypropylene polymers can be used. Examples include the "Bornewables" series from Borealis, the "TRUCIRCLE" series from SABIC, and the "CirculenRenew" series from LyondellBasell.

[0089] Carbon 14 of polyolefin polymers 14 C) The concentration (content) is not particularly limited, but for example, from the viewpoint of reducing environmental impact, it is preferably 0.2 pMC (%) or more, more preferably 0.5 pMC (%) or more, even more preferably 1 pMC (%) or more, particularly preferably 5 pMC (%) or more, and most preferably 10 pMC (%) or more, as measured by the above method. On the other hand, carbon-14 ( 14 C) There is no particular upper limit to the concentration, but for example, from the viewpoint of cost, the pMC(%) measured by the above measurement method is preferably 99 pMC(%) or less, more preferably 95 pMC(%) or less, even more preferably 90 pMC(%) or less, particularly preferably 70 pMC(%) or less, and most preferably 50 pMC(%) or less.

[0090] Carbon 14 of polyolefin polymers 14 C) The concentration can be adjusted by changing the ratio of fossil resource-derived monomers, plant-derived monomers, and chemically recycled monomers used in the production of polyolefin polymers.

[0091] <(A2) Acid-modified polyolefin polymer> The polyolefin polymer composition of the present invention preferably contains (A2) an acid-modified polyolefin polymer as (A) a polyolefin polymer. When the polyolefin polymer composition of the present invention contains (A2) an acid-modified polyolefin polymer, the compatibility between (A) the polyolefin polymer and (C) glass fibers is improved when it is formed into a molded article, thereby strengthening rigidity while maintaining excellent moldability and high explosion resistance. The polyolefin polymer composition of the present invention may contain (A) a polyolefin polymer, or (A2) an acid-modified polyolefin polymer alone, but it is more preferable to contain (A1) a polyolefin polymer and (A2) an acid-modified polyolefin polymer in terms of moldability, explosion resistance, as well as heat insulation, bending rigidity, and flame retardancy, and it is even more preferable to contain (A1-P) a polypropylene polymer and (A2-P) an acid-modified polypropylene polymer.

[0092] In the present invention, (A2) acid-modified polyolefin polymer means a polymer obtained by modifying (A1) polyolefin polymer with an unsaturated carboxylic acid and / or an unsaturated carboxylic acid derivative. The acid-modified (unmodified) polyolefin polymer is not particularly limited and may be a homopolymer of one type of olefin or a copolymer of two or more types of olefins. Examples include the polymers described above in (A1) Polyolefin Polymers. For example, acid-modified polyethylene polymers and (A2-P) Acid-modified polypropylene polymers are preferred as acid-modified polyolefin polymers. Acid-modified polyethylene polymers refer to polymers obtained by modifying the above-mentioned polyethylene polymers with unsaturated carboxylic acids and / or unsaturated carboxylic acid derivatives. Furthermore, (A2-P) acid-modified polypropylene polymers refer to polymers obtained by modifying the above-mentioned (A1-P) polypropylene polymers with unsaturated carboxylic acids and / or unsaturated carboxylic acid derivatives.

[0093] (A2) Acid-modified polyolefin polymers are typically polymers having a substructure of a polyolefin polymer and a substructure derived from an unsaturated carboxylic acid and / or an unsaturated carboxylic acid derivative. Examples of acid-modified polyolefin polymers include (a) polymers obtained by graft polymerization of an unsaturated carboxylic acid and / or an unsaturated carboxylic acid derivative onto a homopolymer of an α-olefin having 2 or more carbon atoms, (b) polymers obtained by graft polymerization of an unsaturated carboxylic acid and / or an unsaturated carboxylic acid derivative onto a random copolymer obtained by copolymerizing two or more α-olefins having 2 or more carbon atoms, and (c) polymers obtained by graft polymerization of an unsaturated carboxylic acid and / or an unsaturated carboxylic acid derivative onto a block copolymer obtained by copolymerizing two or more α-olefins having 2 or more carbon atoms. (A2-P) Acid-modified polypropylene polymers include (a1) polymers obtained by graft polymerization of an unsaturated carboxylic acid and / or an unsaturated carboxylic acid derivative to a propylene homopolymer, (b1) polymers obtained by graft polymerization of an unsaturated carboxylic acid and / or an unsaturated carboxylic acid derivative to a copolymer obtained by copolymerizing propylene with ethylene and one or more other monomers selected from the group consisting of α-olefins having 4 or more carbon atoms, and (c1) modified polypropylene polymers obtained by graft polymerization of an unsaturated carboxylic acid and / or an unsaturated carboxylic acid derivative to a block copolymer obtained by homopolymerizing propylene and then copolymerizing with ethylene and one or more other monomers selected from the group consisting of α-olefins having 4 or more carbon atoms. Examples of acid-modified polyethylene polymers include polymers obtained by replacing propylene with ethylene in the above-mentioned acid-modified polypropylene polymers, and replacing the ethylene in the other monomers with propylene.

[0094] The (A1) polyolefin polymer subjected to acid modification may be a single polymer or a combination of two or more polymers in any ratio. Therefore, the polyolefin polymer subjected to acid modification may also be the heterophagic propylene polymerization material described above.

[0095] Examples of the above-mentioned unsaturated carboxylic acids include maleic acid, fumaric acid, itaconic acid, acrylic acid, and methacrylic acid.

[0096] Examples of the above unsaturated carboxylic acid derivatives include acid anhydrides, ester compounds, amide compounds, imide compounds, and metal salts of unsaturated carboxylic acids. Examples of unsaturated carboxylic acid derivatives include maleic anhydride, itaconic anhydride, methyl acrylate, ethyl acrylate, butyl acrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate, 2-hydroxyethyl methacrylate, monoethyl maleate, diethyl maleate, monomethyl fumarate, dimethyl fumarate, acrylamide, methacrylamide, monoamide maleate, diamide maleate, monoamide fumarate, maleimide, N-butylmaleimide, and sodium methacrylate.

[0097] As unsaturated carboxylic acids, maleic acid and acrylic acid are preferred, and as unsaturated carboxylic acid derivatives, maleic anhydride and 2-hydroxyethyl methacrylate are preferred.

[0098] (A2) As the acid-modified polyolefin polymer, the polymers described in (b) and (c) above are preferred. In the present invention, the (A2-P) acid-modified polypropylene polymer is preferably the polymer described in (b1) and (c1) above, and a modified polypropylene polymer obtained by graft polymerization of maleic anhydride to a polypropylene polymer containing more than 50% by mass of propylene units in the total constituent units is preferred.

[0099] The total content of unsaturated carboxylic acid units and unsaturated carboxylic acid derivative units in the acid-modified polyolefin polymer (also called the "graft rate") is preferably 0.1 to 20% by mass, and more preferably 0.1 to 10% by mass, with the amount of the acid-modified polyolefin polymer being 100% by mass, from the viewpoint of rigidity and hardness of the molded article obtained from the polyolefin polymer composition of the present invention. Here, if the acid-modified polyolefin polymer contains only one of either unsaturated carboxylic acid units or unsaturated carboxylic acid derivative units, the total content refers to the content of that one type of unit.

[0100] The content of unsaturated carboxylic acid units and unsaturated carboxylic acid derivative units is calculated by quantifying the absorption based on unsaturated carboxylic acids and unsaturated carboxylic acid derivatives using infrared absorption spectroscopy or NMR spectroscopy.

[0101] The graft efficiency of the unsaturated carboxylic acid and / or unsaturated carboxylic acid derivative of the acid-modified polyolefin polymer is preferably 0.51 or higher, from the viewpoint of the rigidity and impact strength of the molded article obtained from the polyolefin polymer composition of the present invention.

[0102] "Graft efficiency of acid-modified polyolefin polymers" means "the ratio of the amount of unsaturated carboxylic acid and / or unsaturated carboxylic acid derivatives chemically bonded to the polymer to the total amount of unsaturated carboxylic acid and / or unsaturated carboxylic acid derivatives not chemically bonded to the polymer." The graft efficiency in the graft polymerization of unsaturated carboxylic acid and / or unsaturated carboxylic acid derivatives can be determined by the following procedure (1) to (9).

[0103] (1) Dissolve 1.0 g of acid-modified polyolefin polymer in 100 ml of xylene. (2) Add the xylene solution dropwise to 1000 ml of methanol while stirring to reprecipitate the acid-modified polyolefin polymer. (3) The reprecipitated acid-modified polyolefin polymer is recovered. (4) The recovered acid-modified polyolefin polymer is vacuum-dried at 80°C for 8 hours to obtain a purified acid-modified polyolefin polymer. (5) The purified acid-modified polyolefin polymer is heat-pressed to produce a film with a thickness of 100 μm. (6) Measure the infrared absorption spectrum of the film. (7) From the infrared absorption spectrum, the absorption based on the unsaturated carboxylic acid and / or unsaturated carboxylic acid derivative is quantified, and the content (X1) of the unsaturated carboxylic acid and / or unsaturated carboxylic acid derivative that has reacted with the polyolefin polymer in the acid-modified polyolefin polymer is calculated. (8) Separately, the above procedure (5) to (6) is performed on an acid-modified polyolefin polymer that has not undergone purification, and the content of unsaturated carboxylic acids and / or unsaturated carboxylic acid derivatives (X2) in the acid-modified polyolefin polymer that has not undergone purification is calculated from its infrared absorption spectrum (X2 is the sum of the content of unsaturated carboxylic acids and / or unsaturated carboxylic acid derivatives that have reacted with the polyolefin polymer (X1) and the content of unsaturated carboxylic acids and / or unsaturated carboxylic acid derivatives that have not reacted with the polyolefin polymer (i.e., free)). (9) Equation: Calculate the graft efficiency from graft efficiency = X1 / X2.

[0104] The MFR of acid-modified polyolefin polymers, particularly acid-modified polypropylene polymers, is preferably 5 to 400 g / 10 min, more preferably 10 to 200 g / 10 min, and most preferably 20 to 200 g / 10 min, from the viewpoint of mechanical strength and production stability.

[0105] [(B) Flame retardant] The polyolefin polymer composition of the present invention contains (B) a flame retardant. The polyolefin polymer composition of the present invention may contain one flame retardant alone, or two or more flame retardants in any combination of proportions.

[0106] Examples of flame retardants include halogenated flame retardants, guanidine-based flame retardants, phosphorus-containing flame retardants, metal oxides, and polyhydric hydroxyl group-containing compounds, with phosphorus-containing flame retardants being preferred. The polyolefin polymer composition of the present invention includes both embodiments in which a halogen-based flame retardant is contained in a concentration that exhibits flame retardancy, and embodiments in which a halogen-based flame retardant is not contained in a concentration that exhibits flame retardancy. In the present invention, "not containing a halogen-based flame retardant" means that the polyolefin polymer composition may contain a halogen-based flame retardant in a concentration that does not exhibit flame retardancy, for example, a form in which it is contained in less than 15% by mass of the polyolefin polymer composition.

[0107] Examples of halogenated flame retardants include organic halogenated aromatic compounds. Examples of organic halogenated aromatic compounds include halogenated diphenyl compounds, halogenated bisphenol compounds, halogenated bisphenol bis(alkyl ether) compounds, and halogenated phthalimide compounds.

[0108] Examples of halogenated diphenyl compounds include halogenated diphenyl ether compounds, halogenated diphenyl ketone compounds, and halogenated diphenyl alkane compounds.

[0109] Examples of halogenated bisphenol compounds include halogenated bisphenylalkanes, halogenated bisphenyl ethers, halogenated bisphenyl thioethers, and halogenated bisphenyl sulfones.

[0110] Examples of halogenated bisphenol bis(alkyl ether) compounds include brominated bisphenol A (brominated aliphatic ether), brominated bisphenol S (brominated aliphatic ether), chlorinated bisphenol A (chlorinated aliphatic ether), and chlorinated bisphenol S (chlorinated aliphatic ether), as well as etherified tetrabromobisphenol A and etherified tetrabromobisphenol S.

[0111] Examples of guanidine-based flame retardants include guanidine compounds such as guanidine nitride.

[0112] A phosphorus-containing flame retardant is a flame retardant that contains phosphorus atoms. The polyolefin polymer composition of the present invention preferably contains a phosphorus-containing flame retardant. The polyolefin polymer composition of the present invention may contain a single phosphorus-containing flame retardant, or it may contain two or more in any combination of proportions.

[0113] Examples of phosphorus-containing flame retardants include phosphates, polyphosphates, and phosphate esters.

[0114] Examples of phosphates include melamine orthophosphate, piperazine orthophosphate, melamine pyrophosphate, piperazine pyrophosphate, calcium phosphate, and magnesium phosphate. Specific examples of polyphosphates include ammonium polyphosphate, piperazine polyphosphate, and melamine polyphosphate.

[0115] Examples of phosphates and polyphosphates include salts of orthophosphate with the following bases, salts of pyrophosphate with the following bases, and salts of polyphosphate with the following bases. Examples of bases that can be included in phosphates include N,N,N',N'-tetramethyldiaminomethane, ethylenediamine, N,N'-dimethylethylenediamine, N,N'-diethylethylenediamine, N,N-dimethylethylenediamine, N,N-diethylethylenediamine, N,N,N',N'-tetramethylethylenediamine, N,N'-diethylethylenediamine, 1,2-propanediamine, 1,3-propanediamine, tetramethylenediamine, pentamethylenediamine, hexamethylenediamine, 1,7-diaminoheptane, 1,8-diaminooctane, 1,9-diaminononane, 1,10-diaminodecane, trans-2,5-dimethylpiperazine, 1,4-bis(2-aminoethyl)piperazine, 1,4-bis(3-aminopropyl)piperazine, acetoguanamine, benzoguanamine, acrylicguanamine, 2,4-diamino- 6-nonyl-1,3,5-triazine, 2,4-diamino-6-hydroxy-1,3,5-triazine, 2-amino-4,6-dihydroxy-1,3,5-triazine, 2,4-diamino-6-methoxy-1,3,5-triazine, 2,4-diamino-6-ethoxy-1,3,5-triazine, 2,4-diamino-6-propoxy-1,3,5-triazine, 2,4-diamino-6-isopropoxy-1,3,5-triazine Examples include din, 2,4-diamino-6-mercapto-1,3,5-triazine, 2-amino-4,6-dimercapto-1,3,5-triazine, ammeline, phthalodiguanamine, melamine cyanurate, butylenediguanamine, norbornenediguanamine, methylenediguanamine, ethylenedimelamine, trimethylenedimelamine, tetramethylenedimelamine, hexamethylenedimelamine, and 1,3-hexylenedimelamine.

[0116] The phosphorus-containing flame retardant is preferably one or more selected from the group consisting of melamine pyrophosphate salts, piperazine pyrophosphate salts, and ammonium polyphosphate salts.

[0117] In the present invention, among phosphorus-containing flame retardants, an intomescent flame retardant is preferred. An intomescent flame retardant is a substance that contains phosphorus and nitrogen as its constituent components and can impart flame retardancy to a molded body containing the intomescent flame retardant. When a molded body containing an intomescent flame retardant is burned, the burning heats the body, forming a foamed expansion layer consisting of a foamy film on its surface, thereby exhibiting a high degree of flame retardancy. An intomescent flame retardant can also be described as a substance that has the effect of forming a foamed expansion layer consisting of a foamy film when a molded body containing an intomescent flame retardant is burned.

[0118] Intomessent flame retardants may be compounds containing both phosphorus and nitrogen atoms in their molecules, combinations of compounds containing phosphorus and nitrogen atoms, or combinations of two or more of these. Among these, compounds containing both phosphorus and nitrogen atoms in their molecules, or combinations of compounds containing phosphorus and nitrogen atoms, are preferred in terms of exhibiting a high level of flame retardancy.

[0119] Compounds containing both phosphorus and nitrogen atoms in their molecules include those compounds described above as phosphorus-containing flame retardants, such as polyphosphates including ammonium polyphosphate and melamine polyphosphate, phosphates including melamine phosphate and phosphate ester amides, and pyrophosphates including piperazine pyrophosphate and melamine pyrophosphate. These may be used individually or in combination of two or more.

[0120] In the case of a combination of a compound containing a phosphorus atom and a compound containing a nitrogen atom, examples of compounds containing a phosphorus atom include organophosphorus compounds and red phosphorus. Examples of compounds containing a nitrogen atom include hindered amines, melamine, ammonium borate, and ammonium carbonate. Among these, in terms of flame retardancy, organophosphorus compounds are preferred as the compound containing a phosphorus atom, and hindered amines are preferred as the compound containing a nitrogen atom. That is, it is preferable for an intomescent flame retardant to contain organophosphorus compounds and hindered amines, and it is more preferable to contain only organophosphorus compounds and hindered amines. Note that in the combination of a compound containing a phosphorus atom and a compound containing a nitrogen atom, the "compound containing a phosphorus atom" contains a phosphorus atom but does not include the compound containing a nitrogen atom, and the "compound containing a nitrogen atom" contains a nitrogen atom but does not include the compound containing a phosphorus atom. Examples of organophosphorus compounds include phosphonates, organic phosphites, organic phosphinites, metal salts of phosphinic acid, metal salts of diphosphinic acid, phosphinates, and polyol phosphate alcohols. Among these, phosphonates are preferred because they provide a foamed molded article with superior ignition-proof and self-extinguishing properties. Furthermore, with respect to intomescent flame retardants and organophosphorus compounds, the contents described in International Publication No. 2023 / 181879 may be referenced as appropriate, and those contents are incorporated as part of this specification.

[0121] As phosphorus-containing flame retardants and intomessent flame retardants, those containing both piperazine pyrophosphate and melamine pyrophosphate are preferred, and more preferred flame retardants contain both piperazine pyrophosphate and melamine pyrophosphate, and the mass ratio of the melamine pyrophosphate content to the piperazine pyrophosphate content in the polyolefin polymer composition of the present invention (melamine pyrophosphate / piperazine pyrophosphate) is preferably 0.25 or more and 1.0 or less.

[0122] The molar ratio of pyrophosphate to melamine in melamine pyrophosphate salt is preferably 1:2. The molar ratio of pyrophosphate to piperazine in piperazine pyrophosphate is preferably 1:1.

[0123] Melamine phosphate salts and melamine polyphosphate salts can be obtained by reacting melamine with the corresponding phosphoric acid or polyphosphate or salts thereof. As the melamine pyrophosphate and melamine polyphosphate salts, melamine pyrophosphate and melamine polyphosphate salts obtained by a method of heating and condensing orthophosphate monomelamine may be used, and melamine pyrophosphate and melamine polyphosphate salts obtained by these methods are preferred.

[0124] Piperazine phosphate salts and piperazine polyphosphate salts can be obtained by reacting the corresponding phosphoric acid or polyphosphate, or salts thereof, with piperazine. As the piperazine pyrophosphate and piperazine polyphosphate salts, piperazine pyrophosphate and piperazine polyphosphate salts obtained by a method of heating and condensing mono-orthophosphate of melanin may be used, and piperazine pyrophosphate and piperazine polyphosphate salts obtained by these methods are preferred.

[0125] Commercial phosphates can also be used. Examples of commercially available phosphates include ADEKA's "ADEKA Stab FP-2100J," "ADEKA Stab FP-2200S," "ADEKA Stab FP-2300S," and "ADEKA Stab FP-2500S," Suzuyu Chemical's "FCP-796," Clariant Japan's "EXOLIT AP422" and "EXOLIT AP462," SULI's "Phlamoon-1090A," Chempia's "FR133L," "FR220," and "MPP-D," Xusen's "XS-FR-8300," "XS-FR-8310," "XS-FR-8330," "XS-FR-8340," and "XS-FR-8370," BASF's "Melapur200," and Presafer's "EPFR-110DN."

[0126] Examples of phosphate esters include aromatic phosphate esters, aliphatic phosphate esters, and oligomers or polymers obtained from the aromatic phosphate esters and the aliphatic phosphate esters.

[0127] Examples of aromatic phosphate esters include trixylenyl phosphate, tris(phenyl) phosphate, trinaphthyl phosphate, cresyldiphenyl phosphate, xylenyldiphenyl phosphate, diphenyl-2-methacryloyloxyethyl phosphate, resorcinolbis(diphenyl phosphate), resorcinolbis(dixylenyl phosphate), resorcinolbis(dicresyl phosphate), hydroquinonebis(dixylenyl phosphate), bisphenol Abis(diphenyl phosphate), and tetrakis(2,6-dimethylphenyl)1,3-phenylenebisphosphate.

[0128] Examples of aliphatic phosphate esters include trimethyl phosphate, tributyl phosphate, tri(2-ethylhexyl) phosphate, tributoxyethyl phosphate, monoisodecyl phosphate, and 2-acryloyloxyethyl phosphate.

[0129] Phosphate esters can be commercially available. Examples of commercially available products include "ADEKA Stab FP-600" and "ADEKA Stab FP-800" manufactured by ADEKA Corporation.

[0130] Examples of metal oxides include zinc oxide, magnesium oxide, calcium oxide, silicon dioxide, titanium oxide, manganese oxide (MnO, MnO2), iron oxide (FeO, Fe2O3, Fe3O4), copper oxide, nickel oxide, tin oxide, aluminum oxide, and calcium aluminate. Zinc oxide, magnesium oxide, or calcium oxide are preferred metal oxides, with zinc oxide being more preferred.

[0131] The metal oxide may be surface-treated. Examples of commercially available zinc oxide include Type 2 zinc oxide manufactured by Seido Chemical Industry Co., Ltd., Type 1 zinc oxide manufactured by Mitsui Mining & Smelting Co., Ltd., partially coated zinc oxide manufactured by Mitsui Mining & Smelting Co., Ltd., Nanofine 50 (ultrafine zinc oxide with an average particle size of 0.02 μm: manufactured by Sakai Chemical Industry Co., Ltd.), and Nanofine K (ultrafine zinc oxide coated with zinc silicate with an average particle size of 0.02 μm: manufactured by Sakai Chemical Industry Co., Ltd.).

[0132] A polyhydric hydroxyl group-containing compound is a compound having two or more hydroxyl groups. Examples of polyhydric hydroxyl group-containing compounds include pentaerythritol, dipentaerythritol, tripentaerythritol, polypentaerythritol with a condensation degree of 4 or higher, trishydroxyethyl isocyanate, polyethylene glycol, glycerin, starch, glucose, cellulose, and sorbitol. As a polyhydric hydroxyl group-containing compound, polyhydric alcohol compounds are preferred due to their low water solubility and low hygroscopicity, with pentaerythritol, dipentaerythritol, tripentaerythritol, or polypentaerythritol being more preferred, and pentaerythritol being even more preferred.

[0133] In the present invention, the flame retardant may be used in combination with a flame retardant additive, but it is preferable to use it alone without a flame retardant additive. When a flame retardant additive is used in combination, the content of the flame retardant additive in the polyolefin polymer composition of the present invention is preferably less than 5.0% by mass when the total content of (A) polyolefin polymer, (B) flame retardant, (C) glass fiber and flame retardant additive is taken as 100% by mass.

[0134] [(C) Glass Fiber] The polyolefin polymer composition of the present invention contains (C) glass fibers. The polyolefin polymer composition of the present invention may contain glass fibers alone, or may contain two or more in any combination of proportions.

[0135] (C) The material of the glass fiber is not particularly limited, and any glass can be used. Examples of glass fiber materials include E glass (alkali-free glass), A glass, C glass, S glass, and D glass, with E glass being preferred. As for the glass fiber, any material manufactured by any method can be used.

[0136] As the glass fiber, so-called chopped strands obtained by cutting glass strands may be used. It is preferable to use chopped strands from the viewpoint of further enhancing the rigidity and impact strength of the molded product containing the polyolefin polymer composition while maintaining excellent moldability and high explosion resistance. While long fibers can be used as glass fibers, short fibers are preferable in terms of moldability, explosion resistance, as well as heat insulation, high flame retardancy, and bending rigidity.

[0137] The average diameter of the glass fibers is not particularly limited and may be, for example, 1 μm or more and 50 μm or less. Preferably, the average diameter of the glass fibers is 3 μm or more, more preferably 6 μm or more, preferably 30 μm or less, and more preferably 20 μm or less.

[0138] Weight-average glass fiber length L of glass fibers contained in the molded product G The weight-average glass fiber length L of the glass fiber is not particularly limited, but is preferably 300 μm or more, may be 400 μm or more, and may be 600 μm or less. G Preferably, the particle size is between 300 μm and 550 μm. The weight-average glass fiber length L in glass fibers contained in pellets used for injection molding. GW The above weight-average glass fiber length L is not particularly limited, but for example, G Within this range, the particle size can be 2000 μm or less, and preferably 1000 μm or less.

[0139] Aspect ratio of glass fibers (weight-average glass fiber length L) GThe average glass fiber diameter may be 20 or more, and may be 60 or less. The aspect ratio is preferably 25 or more, more preferably 30 or more, preferably 58 or less, and more preferably 55 or less.

[0140] (C) The average glass fiber diameter, weight-average glass fiber length, and aspect ratio of glass fibers can be measured by the following method. Two g of the polyolefin polymer composition or molded article of the present invention is dissolved in boiling p-xylene for two hours to obtain a xylene-insoluble component containing (C) glass fibers. Next, the (C) glass fibers in the xylene-insoluble component are observed using a microscope, and the length and diameter of 200 (C) glass fibers are measured. The weight-average glass fiber length and average glass fiber diameter for the 200 (C) glass fibers are calculated, and the ratio of the weight-average glass fiber length to the average glass fiber diameter is taken as the aspect ratio of the (C) glass fibers contained in the polyolefin polymer composition or molded article of the present invention. Here, the weight-average glass fiber length can be calculated according to the following formula. Weight-average glass fiber length (Lw) = (Σqi × Li 2 ) / (Σqi×Li) In the above formula, Li is the length of the glass fiber (glass fiber length), and qi is the number of glass fibers having glass fiber length Li.

[0141] A method for adjusting the (C) glass fibers contained in the polyolefin polymer composition or molded article of the present invention to within the above aspect ratio range includes appropriately adjusting the supply position of the (C) glass fibers to the extruder, the temperature of the extruder, the screw rotation speed, the melt flow rate of the polyolefin polymer used as raw material, the length (glass fiber length) and glass fiber diameter of the (C) glass fibers used as raw material when the raw materials are kneaded in the extruder. For example, increasing the extruder temperature when producing the polyolefin polymer composition of the present invention can usually increase the aspect ratio and glass fiber length. The extruder temperature is preferably 180°C or higher, more preferably 190°C or higher, even more preferably 200°C or higher, and preferably 250°C or lower. In addition, increasing the melt flow rate of the raw material (A) polyolefin polymer can usually increase the aspect ratio and glass fiber length.

[0142] In the preparation of the polyolefin polymer composition of the present invention, glass fiber-containing resin pellets (glass fiber-containing resin pellets) may be used as glass fibers. In glass fiber-containing pellets, the length of the glass fibers (glass fiber length) usually coincides with the length in the extrusion direction of the resin pellet.

[0143] Glass fiber-containing resin pellets can be manufactured by any method. For example, glass fiber-containing resin pellets can be manufactured by pultrusion. Pultrusion is a method in which multiple continuous glass fibers are drawn out while molten resin is extruded from a resin extruder to impregnate the bundle of glass fibers and integrate the bundles of glass fibers into one. The resin-impregnated bundles of glass fibers are usually cooled and cut with a pelletizer to obtain glass fiber-containing resin pellets.

[0144] The glass fiber content in the glass fiber-containing resin pellets is preferably 50 to 99.9% by mass.

[0145] <Surface treatment of glass fibers> The glass fibers may be treated with a sizing agent and / or a surface treatment agent.

[0146] (A) Glass fibers are preferably surface-treated with a surface treatment agent, from the viewpoint of improving dispersibility in polyolefin polymers. Examples of surface treatment agents include organosilane coupling agents, titanate coupling agents, aluminate coupling agents, zirconate coupling agents, silicone compounds, higher fatty acids, higher fatty acid metal salts, and fatty acid esters.

[0147] Examples of organosilane coupling agents include vinyltrimethoxysilane, γ-chloropropyltrimethoxysilane, γ-methacryloxypropyltrimethoxysilane, γ-aminopropyltrimethoxysilane, and 3-acryloxypropyltrimethoxysilane.

[0148] Examples of titanate coupling agents include isopropyltriisostearoyl titanate, isopropyltris(dioctyl pyrophosphate) titanate, and isopropyltri(N-aminoethyl) titanate.

[0149] Examples of aluminate coupling agents include acetalkoxyaluminum diisopropylate. Examples of zirconate coupling agents include tetra(2,2-diallyloxymethyl)butyl, di(tridecyl)phosphite zirconate, and neopentyl(diallyl)oxytrineodecanoyl zirconate. Examples of the silicone compounds mentioned above include silicone oil and silicone resin.

[0150] Examples of higher fatty acids include oleic acid, capric acid, lauric acid, palmitic acid, stearic acid, montanic acid, linoleic acid, rosinic acid, linolenic acid, undecanoic acid, and undecenoic acid.

[0151] Examples of higher fatty acid metal salts include sodium salts, lithium salts, calcium salts, magnesium salts, zinc salts, and aluminum salts of fatty acids with 9 or more carbon atoms (e.g., stearic acid, montanic acid). Among these, calcium stearate, aluminum stearate, calcium montanate, and sodium montanate are preferred.

[0152] Examples of fatty acid esters include polyhydric alcohol fatty acid esters such as glycerin fatty acid esters, alpha-sulfo fatty acid esters, polyoxyethylene sorbitan fatty acid esters, sorbitan fatty acid esters, polyethylene fatty acid esters, and sucrose fatty acid esters.

[0153] The amount of the above surface treatment agent used is not particularly limited, but is preferably 0.01 to 5 parts by mass, and more preferably 0.1 to 3 parts by mass, per 100 parts by mass of glass fiber.

[0154] When the glass fibers are long fibers, it is preferable that they be treated with a sizing agent. Glass fibers treated with a sizing agent are bound together. Examples of sizing agents include epoxy sizing agents, aromatic urethane sizing agents, aliphatic urethane sizing agents, acrylic sizing agents, and maleic anhydride-modified polyolefin sizing agents. The sizing agent is preferably one that melts at the melt kneading temperature with (A) the polyolefin polymer, and more preferably one that melts at 200°C or below.

[0155] Commercially available glass fibers can be used.

[0156] [Other ingredients] In addition to the components (A) to (C) described above, the polyolefin polymer composition of the present invention may also contain other components (hereinafter sometimes referred to as "other components") as optional components. Other components include elastomers, neutralizing agents, antioxidants, UV absorbers, lubricants, antistatic agents, antiblocking agents, processing aids, organic peroxides, colorants (inorganic pigments, organic pigments, etc.), pigment dispersants, foaming agents, foaming nucleating agents, plasticizers, crosslinking agents, crosslinking aids, brightness enhancers, antibacterial agents, light diffusing agents, and molecular weight modifiers. The polyolefin polymer composition of the present invention may contain the other components individually or in any combination of two or more components in any ratio.

[0157] Examples of elastomers include random copolymers having ethylene units and α-olefin units having 4 to 10 carbon atoms. Preferably, the random copolymer has an MFR of 0.1 to 50 g / 10 min.

[0158] Examples of α-olefins having 4 to 10 carbon atoms that constitute the above-mentioned random copolymer, which is an elastomer, include α-olefins similar to those that can constitute polyethylene polymers, such as linear or branched α-olefins like 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 1-octene, and 1-decene, and cyclic α-olefins like vinylcyclopropane, vinylcyclobutane, and vinylcyclohexane, with 1-butene, 1-hexene, and 1-octene being preferred.

[0159] Examples of the above-mentioned random copolymers that are elastomers include ethylene-1-butene random copolymer, ethylene-1-hexene random copolymer, ethylene-1-octene random copolymer, ethylene-1-decene random copolymer, ethylene-(3-methyl-1-butene) random copolymer, and copolymers of ethylene and α-olefins having a cyclic structure.

[0160] The α-olefin content in the above random copolymer is preferably 1 to 49% by mass, more preferably 5 to 49% by mass, and even more preferably 24 to 49% by mass, with the mass of the random copolymer being 100% by mass.

[0161] Furthermore, from the viewpoint of improving the impact resistance of molded articles containing the polyolefin polymer composition of the present invention, the density of the random copolymer is preferably 0.850 to 0.890 g / cm³. 3 And more preferably 0.850~0.880 g / cm³ 3 And more preferably 0.855~0.867 g / cm³ 3 That is the case.

[0162] The above-mentioned random copolymer, which is an elastomer, can be produced by polymerizing monomers using a polymerization catalyst. Examples of polymerization catalysts include those listed as polymerization catalysts for producing the above-mentioned polypropylene polymer.

[0163] Commercially available products may be used as the above random copolymer. Examples of commercially available products that are elastomers and are random copolymers include Engage® manufactured by Dow Chemical Japan, Tuffmer® manufactured by Mitsui Chemicals, Neozex® and Ultzex® manufactured by Prime Polymer, and Excellen FX®, Sumikasen® and Esprene SPO® manufactured by Sumitomo Chemical.

[0164] At least one of the various components used as raw materials in the production of the polyolefin polymer of the present invention, such as (A) a polyolefin polymer, (B) a flame retardant, and (C) glass fibers, may include in-process scraps, crushed market recovered products, melt-kneaded products, and recycled products.

[0165] [Content of each component in the polyolefin polymer composition] <(A) Content of polyolefin polymer> The total content of (A) polyolefin polymer in the polyolefin polymer composition of the present invention is not particularly limited, but in terms of moldability, explosion resistance, as well as heat insulation, bending rigidity, and flame retardancy, when the total content of (A) polyolefin polymer, (B) flame retardant, and (C) glass fiber is taken as 100% by mass, it is preferably 10 parts by mass or more, more preferably 15 parts by mass or more, even more preferably 20 parts by mass or more, particularly preferably 25 parts by mass or more, on the other hand, it is preferably 60 parts by mass or less, more preferably 55 parts by mass or less, even more preferably 49 parts by mass or less, and particularly preferably 42 parts by mass or less.

[0166] ((A1) Polyolefin polymer content) The content of (A1) polyolefin polymer in the polyolefin polymer composition of the present invention can be appropriately set considering the total content of (A) polyolefin polymer. For example, in terms of moldability and explosion resistance, as well as heat insulation, bending rigidity and flame retardancy, when the total content of (A) polyolefin polymer, (B) flame retardant and (C) glass fiber is 100% by mass, it is preferably 10 parts by mass or more, more preferably 15 parts by mass or more, even more preferably 20 parts by mass or more, particularly preferably 25 parts by mass or more, on the other hand, it is preferably 60 parts by mass or less, more preferably 55 parts by mass or less, even more preferably 49 parts by mass or less, and particularly preferably 42 parts by mass or less. When (A1) the polyolefin polymer includes (A1-P) the polypropylene polymer, the content of (A1-P) the polypropylene polymer in the polyolefin polymer composition of the present invention can be appropriately set considering the total content of (A) the polyolefin polymer and the content of (A1) the polyolefin polymer. For example, the content of (A1-P) the polypropylene polymer can be in the same range as the content of (A1) the polyolefin polymer.

[0167] ((A2) Content of acid-modified polyolefin polymers) The content of (A2) acid-modified polyolefin polymer in the polyolefin polymer composition of the present invention can be appropriately set considering the total content of (A) polyolefin polymer. For example, in terms of moldability and explosion resistance, as well as heat insulation, bending rigidity and flame retardancy, when the total content of (A) polyolefin polymer, (B) flame retardant and (C) glass fiber is 100% by mass, the content is preferably 0.1% by mass or more, more preferably 0.2% by mass or more, even more preferably 0.5% by mass or more, preferably 5.0% by mass or less, more preferably 3.0% by mass or less, and even more preferably 2.5% by mass or less. When (A2) acid-modified polyolefin polymers include (A2-P) acid-modified polypropylene polymers, the content of (A2-P) polypropylene polymers in the polyolefin polymer composition of the present invention can be appropriately set considering the total content of (A) polyolefin polymers and the content of (A2) polyolefin polymers. For example, the content of (A2-P) acid-modified polypropylene polymers can be in the same range as the content of (A2) acid-modified polyolefin polymers.

[0168] <(B) Flame retardant content> The content of (B) flame retardant in the polyolefin polymer composition of the present invention is preferably 5% by mass or more, more preferably 10% by mass or more, even more preferably 12% by mass or more, preferably 25% by mass or less, more preferably 18% by mass or less, and even more preferably 15% by mass or less, when the total content of (A) polyolefin polymer, (B) flame retardant and (C) glass fiber is taken as 100% by mass, in terms of moldability, explosion resistance, flame retardancy, and furthermore, heat insulation and bending rigidity.

[0169] (Content of phosphorus-containing flame retardant) If the polyolefin polymer composition of the present invention contains a phosphorus-containing flame retardant, the amount of phosphorus-containing flame retardant that may be included in the polyolefin polymer composition of the present invention can be appropriately determined considering the amount of the flame retardant (B) above. For example, when the total amount of (A) polyolefin polymer, (B) flame retardant, and (C) glass fiber is 100% by mass, the amount of phosphorus-containing flame retardant can be more than 4% by mass, and preferably the same as the amount of the flame retardant (B) above. If the polyolefin polymer composition of the present invention contains a phosphorus-containing flame retardant, the content of flame retardants other than the phosphorus-containing flame retardant that may be included in the polyolefin polymer composition of the present invention can be appropriately set considering the content of the above-mentioned (B) flame retardant. The content of flame retardants other than the phosphorus-containing flame retardant is preferably 0 to 15% by mass, more preferably 0 to 10% by mass, even more preferably 0 to 5% by mass, and may be 0% by mass, when the total content of (A) polyolefin polymer, (B) flame retardant and (C) glass fiber is taken as 100% by mass.

[0170] <(C) Glass fiber content> The content of (C) glass fibers in the polyolefin polymer composition of the present invention is not particularly limited, but in terms of moldability, explosion resistance, as well as heat insulation, flame retardancy, and bending rigidity, when the total content of (A) polyolefin polymer, (B) flame retardant and (C) glass fibers described later is taken as 100% by mass, it is preferably 30% by mass or more, more preferably 41% by mass or more, even more preferably 44% by mass or more, preferably 70% by mass or less, more preferably 65% ​​by mass or less, and even more preferably 58% by mass or less.

[0171] In the polyolefin polymer composition of the present invention, the mass ratio of the content of (B) flame retardant to the content of (C) glass fibers [(B) flame retardant content / (C) glass fiber content] is 0.5 or less. When the above mass ratio [(B) flame retardant content / (C) glass fiber content] is 0.5 or less, high explosion resistance can be achieved while maintaining excellent moldability. The above mass ratio [(B) flame retardant content / (C) glass fiber content] is preferably 0.35 or less, and more preferably 0.33 or less, in order to achieve a high level of both moldability and explosion resistance, and further excel in heat insulation, bending rigidity, and flame retardancy. The lower limit of the above mass ratio [(B) flame retardant content / (C) glass fiber content] is not particularly limited, but in terms of flame retardancy it can be 0.1 or more, and in terms of moldability, explosion resistance, and further in terms of heat insulation, flame retardancy, and bending rigidity it is preferably 0.20 or more, and more preferably 0.25 or more.

[0172] In the polyolefin polymer composition of the present invention, the total content of other components is not particularly limited and can be set as appropriate. For example, it can be 0 to 30 parts by mass per 100 parts by mass of the total content of (A) polyolefin polymer, (B) flame retardant, and (C) glass fiber. In the polyolefin polymer composition of the present invention, the elastomer content can be appropriately set considering the total content of the other components. For example, the elastomer content is preferably 0 to 30 parts by mass, and more preferably 0 to 10 parts by mass, based on 100 parts by mass of the total content of (A) polyolefin polymer, (B) flame retardant, and (C) glass fiber. In the present invention, the elastomer content in the polyolefin polymer composition of the present invention can also be 5 to 30% by mass.

[0173] [Physical properties of polyolefin polymer compositions] The polyolefin polymer composition of the present invention preferably has a melt flow rate (230°C, 2.16 kgf) of 0.1 g / 10 min or more, more preferably 1 g / 10 min or more, preferably 400 g / 10 min or less, more preferably 300 g / 10 min or less, and even more preferably 200 g / 10 min or less. When the MFR of the polyolefin polymer composition of the present invention is within the above range, it exhibits excellent moldability. Furthermore, by having an MFR below the upper limit of the above range, the flame retardancy of the polyolefin polymer composition of the present invention can be effectively improved, and by having an MFR above the lower limit of the above range, the weld strength of the molded article containing the polyolefin polymer composition of the present invention can be improved.

[0174] The polyolefin polymer composition of the present invention preferably has a specific gravity of 1.0 or higher, more preferably 1.2 or higher, more preferably 1.8 or lower, and more preferably 1.6 or lower, as measured by the method described in the examples below.

[0175] In the present invention, the polyolefin polymer composition of the present invention is not particularly limited in its properties or form, as long as it contains (A) a polyolefin polymer, (B) a flame retardant, and (C) glass fibers. It includes mixtures of each component (molten kneaded product), such as strands and pellets, as well as molded products. The pellet shape is not particularly limited and examples include granular and tablet shapes. For example, it can be produced by preparing a strand-shaped polyolefin polymer composition and then cutting it to an appropriate length. In the present invention, "unmolded product" refers to a product that has not been molded into a shape and dimensions suitable for various applications and is used as a molding material, while "molded product" refers to a product that has been molded into a shape and dimensions suitable for various applications.

[0176] [Method for producing polyolefin polymer compositions] The polyolefin polymer composition of the present invention can be produced by known methods, and can usually be produced by melt-kneading each of the components already described. The order in which the components are kneaded is not particularly limited. For example, all components may be put into a melt-kneading apparatus all at once and kneaded, or a mixture obtained by kneading some of the components may be kneaded with the remaining components. Here, the kneading method and timing of (C) glass fibers are not particularly limited, but it is preferable to use the kneading method and timing described in the preferred production method described later.

[0177] The melt-mixing temperature is not particularly limited and can be determined as appropriate. The melt-mixing temperature is usually preferably 170°C or higher, more preferably 180°C or higher, even more preferably 200°C or higher, and preferably 250°C or lower. The melt-mixing time is also not particularly limited and can be determined as appropriate.

[0178] Conventional known melt kneading apparatus can be used as the melt kneading apparatus for the production of the polyolefin polymer composition of the present invention. Suitable melt kneading apparatuses include, for example, Banbury mixers, single-screw extruders, twin-screw co-rotating extruders, and twin-screw anomalous rotating extruders. Examples of melt kneading apparatuses include ZSK (registered trademark) from Coperion, TEM (registered trademark) from Toshiba Machine Co., Ltd., TEX (registered trademark) from Japan Steel Works Ltd., KZW (registered trademark) from Technovel Co., Ltd., CMP (registered trademark) and TEX (registered trademark) from Japan Steel Works Ltd., and FCM (registered trademark), NCM (registered trademark), and LCM (registered trademark) from Kobe Steel, Ltd.

[0179] A preferred method for producing the polyolefin polymer composition of the present invention is to supply a raw material (1) containing (A) a polyolefin polymer and (B) a flame retardant into the cylinder of a twin-screw kneading extruder equipped with a cylinder and two screws, at a distance L1 from the upstream end of the two screws, and to supply (C) glass fibers into the cylinder at a distance L2 from the upstream end of the two screws, and then melt-knead the mixture. Here, L1 / L is preferably in the range of 0 or more and less than 0.3, L2 / L is preferably in the range of 0.3 to 0.9, more preferably 0.5 or more, even more preferably 0.6 or more, particularly preferably 0.5 to 0.9, and most preferably 0.6 to 0.9. Generally, reducing L2 / L can reduce the aspect ratio of the (C) glass fibers contained in the polyolefin polymer composition of the present invention, and increasing L2 / L can increase the aspect ratio. Here, L is the length of the screw from the upstream end to the downstream end in the direction of the resin flow being mixed (i.e., the total length of the screw). The above preferred manufacturing method is particularly suitable when producing a polyolefin polymer composition containing glass fibers as (C) glass fibers.

[0180] The raw material (1) may optionally contain a molecular weight modifier for adjusting the molecular weight of the polyolefin polymer. Examples of molecular weight modifiers include organic peroxides. The molecular weight modifier may be included in the raw material (1) in the form of a masterbatch diluted with any resin.

[0181] The polyolefin polymer composition of the present invention preferably has an MFR within the above range and exhibits excellent moldability, allowing it to be molded into desired shapes and dimensions in various molding methods, particularly injection molding. Furthermore, the polyolefin polymer composition of the present invention also satisfies the explosion resistance performance (test specimen thickness: 1 to 10 mm) in the BETR test of the UL2596 standard and preferably exhibits high thermal insulation properties. Moreover, when a test specimen with a thickness of 3 mm is used, the polyolefin polymer composition of the present invention exhibits self-extinguishing properties equivalent to the V-0 judgment criterion in the vertical combustion test specified in UL94, demonstrating a high degree of flame retardancy. In addition, the polyolefin polymer composition of the present invention can form molded articles with excellent bending rigidity. The polyolefin polymer composition of the present invention, exhibiting such excellent performance, is suitable as a material for forming molded articles, particularly molded articles capable of achieving high explosion resistance, and is suitable as a material for forming injection molded articles, focusing on the molding method.

[0182] [[Molded body]] The molded article of the present invention is a molded article comprising the polyolefin polymer composition of the present invention. The molded article of the present invention is a molded article obtained by molding a molten mixture of the above components or the polyolefin polymer composition of the present invention by a known molding method.

[0183] The polyolefin polymer composition of the present invention contained in the molded article is the same as that described above in [Polyolefin Polymer Composition of the Present Invention].

[0184] The molded article can be molded simultaneously with or continuously with the preparation (melt mixing) of the polyolefin polymer composition of the present invention, or it can be obtained by preparing the polyolefin polymer composition of the present invention and then molding the polyolefin polymer composition again using various molding methods. The molding method is not particularly limited, and known molding methods can be applied. For example, injection molding, extrusion molding, compression molding, mold molding, vacuum molding, sheet molding, roll molding, hot press molding, foam molding, injection press molding, blow molding, gas injection molding, etc., can be applied, with injection molding being preferred. In addition to 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 can be applied as injection molding methods. The molded article of the present invention is preferably an injection-molded article formed by injection molding.

[0185] The molding conditions in each molding method are not particularly limited as long as the molten mixture of the above components or the polyolefin polymer composition of the present invention can be molded in a molten state. They can be appropriately set according to the composition and physical properties of the molten mixture of the above components or the polyolefin polymer composition of the present invention, and the kneading method and kneading conditions (kneading temperature) used in the preparation of the polyolefin polymer composition of the present invention can be preferably applied. The shape and size of the molded body of the present invention are determined appropriately according to the application. For example, the thickness of the molded body can be 1 mm or more and less than 10 mm, and preferably 2 mm or more and less than 4 mm. In the present invention, the thickness of the molded body refers to the thickness at any measurement point or the average thickness in the case of a molded body having substantially the same thickness, such as a plate-shaped molded body, and refers to the maximum thickness in the case of a molded body having different thicknesses, such as a housing. The shape of the molded body is determined appropriately according to the application, and examples include plate-shaped and hollow box-shaped (housing shape).

[0186] The molded article of the present invention may consist solely of a molded article of the polyolefin polymer composition of the present invention, or it may consist of the above-mentioned molded article and other components. Examples of other components include a surface layer (coating layer), a colored layer, and a reinforcing layer. Furthermore, the molded article of the present invention may be subjected to surface treatments such as hard coating, water-repellent treatment, and antibacterial treatment as needed.

[0187] The molded article of the present invention contains the polyolefin polymer composition of the present invention, satisfies the explosion resistance performance in the BETR test of the UL2596 standard, and preferably also exhibits high thermal insulation properties. Furthermore, when the molded article of the present invention is a 3 mm thick test piece, it exhibits self-extinguishing properties corresponding to the V-0 judgment criterion in the vertical combustion test specified in UL94, and also exhibits high flame retardancy. In addition, the molded article of the present invention has excellent bending rigidity. The molded article of the present invention preferably has a bending modulus of 9 to 20 GPa as described in the examples below. Furthermore, although the molding article of the present invention is not unique to its thickness, for example, when the thickness is 1 to 10 mm, the bending rigidity as described in the examples below is 300 to 10000 GPa·mm 3 It is preferable that this is the case. The specific gravity of the molded article of the present invention, as measured by the method described later in the examples, is not particularly limited, but it is preferable that it is the same as the specific gravity of the polyolefin polymer composition of the present invention.

[0188] Examples of molded articles of the present invention include injection molded articles, extruded articles, compression molded articles, irregularly shaped molded articles, vacuum molded articles, sheet molded articles, roll molded articles, hot press molded articles, foam molded articles, injection press molded articles, blow molded articles, and gas-injected molded articles, and it is preferable that the injection molded article is molded taking advantage of the excellent moldability of the polyolefin polymer composition of the present invention.

[0189] The molded articles of the present invention can be used as various parts for vehicles, home appliances, industrial products, etc., and are particularly suitable for use as vehicle parts for electric vehicles and plug-in hybrid vehicles, and especially suitable for use as battery parts, peripheral parts, or charging stations for electric vehicles, plug-in hybrid vehicles, electric trucks, electric buses, electric motorcycles, etc. Examples of industrial products include batteries and peripheral components for AGVs and AMRs. Examples of vehicle parts include interior and exterior parts, engine compartment parts, and battery parts. Examples of interior and exterior parts of automobiles include instrument panels, door trims, pillars, side protectors, console boxes, column covers, bumpers, fenders, and wheel covers. Examples of engine compartment parts of vehicles include engine covers. Examples of battery parts or related parts include battery cases (battery enclosures), charger connectors, and high-capacity charger connectors. [Examples]

[0190] The present invention will be described in more detail below with reference to examples. However, the present invention is not limited to these examples.

[0191] In the following explanation, "%" and "parts" represent quantities based on mass unless otherwise specified. Furthermore, the operations described below were performed under normal temperature and pressure conditions unless otherwise specified.

[0192] The components used in the examples and comparative examples are shown below. 1. (A1) Production of polyolefin polymers <(A1-P) Propylene Homopolymer Production> (A1-P)propylene homopolymer was produced by gas-phase polymerization under conditions that yielded a polypropylene polymer with the following properties, using a polymerization catalyst obtained by the method described in Example 1 of Japanese Patent Publication No. 2004-182981. (A1-P)Propylene Homopolymer MFR (230℃, load 2.16kgf) is 120g / 10min

[0193] <(A2-P) Acid-Modified Polypropylene Polymer Production> (A2) As an acid-modified polyolefin polymer, maleic anhydride-modified polypropylene (hereinafter sometimes referred to as "acid-modified PP") was produced as follows. Specifically, 100 parts by mass of polypropylene resin powder (intrinsic viscosity [η] = 3.0 dl / g, ethylene content 0.2% by mass) were mixed with 1.0 part by mass of maleic anhydride, 0.14 parts by mass of di-(tert-butylperoxy)diisopropylbenzene (product name: Perbutyl P, manufactured by NOF Corporation), 0.05 parts by mass of dicetyl peroxydicarbonate (product name: Percadox 24FL, manufactured by Kayaku Akzo Co., Ltd.), 0.05 parts by mass of calcium stearate (product name: AR-2, manufactured by Sakai Chemical Industry Co., Ltd.), and 0.3 parts by mass of the antioxidant pentaerythritol tetrakis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] (product name: Songnox 1010, manufactured by SONGWON Corporation). After thorough pre-mixing, the mixture was fed through the feed port of a twin-screw extruder and kneaded to obtain (A2-P) acid-modified PP. The resulting acid-modified PP had an MFR (at 230°C and a load of 2.16 kgf) of 170 g / 10 min and a grafting rate of 0.32%.

[0194] 2. (B) Flame retardants The following flame retardants were prepared. (B-1) Flame retardant (phosphorus-containing flame retardant: Intomescent flame retardant) Product Name: ADEKA Stub FP-2300S (Manufactured by ADEKA Corporation) Main components: Melamine phosphate, piperazine phosphate (B-2) Flame retardant (phosphorus-containing flame retardant: Intomescent flame retardant) Product name: HP-FR-8300 (manufactured by Xusen) Main component: Ammonium polyphosphate

[0195] 3. (C) Fiberglass The following glass fibers were prepared. (C-1) Glass fiber (short fibers, chopped strands) Product name: ESC03T-480H (manufactured by Nippon Electric Glass Co., Ltd.) Diameter: 10.5 μm (catalog value) Glass fiber length: 3.0 mm (catalog value)

[0196] [evaluation] The evaluation was conducted according to the test methods described below. <Melt Flow Rate (MFR) (Unit: g / 10 min)> The measurement was performed according to the method specified in JIS K7210, at a temperature of 230°C and a load of 2.16 kgf.

[0197] <Explosion resistance and thermal insulation according to UL2596-BETR standard> Each polypropylene polymer composition prepared in the examples and comparative examples was supplied to an injection molding machine, Japan Steel Works Ltd. "JSW280EII-SP," and injection molding was performed under conditions of a molding temperature of 240°C and a mold cooling temperature of 85°C to produce a 300 mm (length) × 210 mm (width) flat plate (thickness as shown in Table 1). A 200 mm (length) × 200 mm (width) test specimen (thickness as shown in Table 1) was cut from the center of the obtained flat plate. Here, the length of the flat plate coincides with the MD direction (Machine Direction: the direction parallel to the flow direction of the polyolefin polymer composition during injection molding), and the length of the test specimen coincides with the length of the flat plate. Using the obtained test specimen, the explosion resistance and thermal insulation performance of the test specimen were evaluated according to the UL2596-BETR standard. In Reference Example 1, a 200 mm (length) × 200 mm (width) × 1.4 mm (thickness) steel plate was used as the test specimen. Specifically, in accordance with the UL2596-BETR standard, 25 18650-type cylindrical lithium-ion batteries (Panasonic NCR18650B) were placed in a steel test box with a 16mm diameter opening (orifice). After covering the box with a test specimen, the batteries were subjected to thermal runaway, and the combustion state of the test specimen was evaluated. The opening (orifice) was adjusted to achieve a predetermined target pressure, for example, a diameter of 16mm. The explosion resistance performance was evaluated by visually inspecting the test specimen for any visible damage 5 minutes after the battery's thermal runaway occurred. As a result, specimens that did not develop holes (no damage) were classified as "no holes," while specimens with holes (damage) were classified as "had holes." Specimens classified as "no holes" demonstrate high resistance to combustion (ignition) and explosion caused by thermal runaway of the battery, and can be said to achieve high safety as battery components. Note that Comparative Example 3 did not exhibit self-extinguishing properties (passed the judgment criterion V-0) according to UL94-V, which will be described later, and it was considered that the fire would not be extinguished and the specimen would burn completely according to the standard UL2596-BETR, so this evaluation was not performed (indicated as "-" in Table 1). The thermal insulation performance was evaluated by measuring the temperature difference between the inner and outer surfaces of a test specimen (without holes) over a 5-minute period, from the onset of battery thermal runaway to 5 minutes afterward. For each test specimen, the highest surface temperature on the inner side (facing the inside of the test box and directly receiving flames from the battery's thermal runaway) was defined as the "inside temperature," and the highest surface temperature on the opposite side was defined as the "top temperature." The difference between these two temperatures was defined as the "inside-top temperature." A larger "inside-top temperature" indicates that the heat generated by the battery's thermal runaway is less likely to be transmitted to the surroundings (outside the battery), resulting in higher thermal insulation performance and greater safety as a battery component.

[0198] <Moldability> The moldability of each polypropylene polymer composition was evaluated in the above-mentioned evaluation of <explosion resistance and thermal insulation performance according to standard UL2596-BETR> by determining whether or not a molded body of the specified dimensions and shape could be injection molded. The evaluation was marked as "○" if a flat plate of 300 mm (length) x 210 mm (width) (thickness as shown in Table 1) could be produced, and "×" if injection molding was not possible.

[0199] <Self-extinguishing property> The self-extinguishing properties of each polypropylene polymer composition prepared in the examples and comparative examples, as well as the steel plate in the reference example, were evaluated by a flammability test according to the UL94-V standard. Specifically, each polypropylene polymer composition was supplied to an injection molding machine, "IS100EN" manufactured by Toshiba Machine Co., Ltd., and injection molding was performed under conditions of a molding temperature of 220°C and a mold cooling temperature of 50°C to produce a test plate measuring 160 mm (length) × 160 mm (width) × 3.0 mm (thickness). From the obtained 3.0 mm thick test plate, a test specimen measuring 127 mm (length) × 13 mm (width) × 3.0 mm (thickness) was cut in the MD direction. For reference example 1, a steel plate measuring 127 mm (length) × 13 mm (width) × 1.4 mm (thickness) was used as the test specimen. The flame retardancy of the obtained test specimens was evaluated according to the UL94-V standard. The evaluation followed the UL94-V standard, with a "○" indicating self-extinguishing properties if it passed the V-0 standard, and a "×" indicating non-self-extinguishing properties if it failed the V-0 standard. The results of the flammability test according to the UL94-V standard are listed in the "UL94" column of Table 1.

[0200] <Specific gravity> Type A1 dumbbell test specimens (with thicknesses as shown in Table 1) were prepared by injection molding using each polypropylene polymer composition, in accordance with JIS K 7139. The specific gravity at 23°C was measured according to the liquid weighing method specified in JIS Z 8807. Reference Example 1 used a Type A1 dumbbell test specimen made from steel plate.

[0201] <Flexural modulus and bending stiffness> Type A1 dumbbell test specimens (with thicknesses as shown in Table 1) were prepared by injection molding using each polypropylene polymer composition, in accordance with JIS K 7139, and the flexural modulus was measured according to JIS K 7171. The longitudinal direction of each Type A1 dumbbell test specimen coincides with the MD direction. Note that Reference Example 1 used a Type A1 dumbbell test specimen made from steel plate. The bending stiffness was calculated from the measured bending modulus of elasticity according to the following formula. In addition, the "Ratio to Iron" column in Table 1 shows the ratio of the bending stiffness of each test specimen to the bending stiffness of the steel plate in Reference Example 1. Bending stiffness = Bending modulus × (Thickness of the specimen cubed) (Unit: GPa·mm) 3 )

[0202] [Example 1] (A1-P) 39.5 parts by mass of polypropylene, (A2-P) 1.5 parts by mass of acid-modified PP, (B-1) flame retardant 14.0 parts by mass of flame retardant, and 100 parts by mass of components (A), (B) and (C) described later, to which 0.05 parts by mass of neutralizing agent, 0.55 parts by mass of antioxidant, and 0.2 parts by mass of organic peroxide masterbatch were melt-kneaded in a twin-screw kneading extruder at a temperature of 200-230°C and a screw rotation speed of 400 rpm. Furthermore, 45.0 parts by mass of (C-1) glass fiber were side-fed from a position midway through the extruder, specifically about 70% of the total screw length (L2 / L=0.7), passed through a chilled water bath, and then the strands were cut with a strand cutter to obtain pellets (corresponding to a polypropylene polymer composition). The obtained pellets were dried in a hot air dryer at 100°C for 2 hours, and then molded using each of the molding machines used in the above evaluation to produce injection-molded articles.

[0203] [Examples 2-3 and Comparative Examples 1-3] Except for changing components (A) to (C) in Example 1 to the components and their respective contents shown in Table 1, pellets of the polypropylene polymer compositions of Examples 2-3 and Comparative Examples 1-3 were obtained in the same manner as in Example 1, and injection molded articles of Examples 2-3 and Comparative Examples 1-3 were manufactured.

[0204] [Reference example 1] A 1.4mm thick steel plate was used.

[0205] Each obtained polypropylene polymer composition was evaluated using pellets or steel plates according to the evaluation method described above. The results are shown in Table 1. The average glass fiber diameter and weight-average glass fiber length L of the (C-1) glass fibers present in each of the polypropylene polymer compositions and injection-molded articles of Examples 1 to 3 are as follows: G The aspect ratios were all confirmed to be within the aforementioned ranges (1–50 μm, 300–600 μm, and 20–60, respectively).

[0206] [Table 1]

[0207] In Table 1, blank spaces in the content columns for components (A) to (C) indicate a content of 0 parts by mass. Furthermore, "Mass ratio [(B) / (C)]" represents the mass ratio of the content of (B) flame retardant to the content of (C) glass fiber [(B) flame retardant content / (C) glass fiber content].

[0208] The results shown in Table 1 reveal the following: In other words, even though Comparative Examples 1 and 2 contain (A) a polyolefin polymer, (B) a flame retardant, and (C) glass fibers, the mass ratio [(B) flame retardant content / (C) glass fiber content] is too high, causing the test specimens to break in the UL2596-BETR test and failing to demonstrate sufficient explosion-proof performance. Similarly, Comparative Example 3 does not exhibit self-extinguishing properties (passes the V-0 criterion) and is inferior in flame retardancy. These comparative examples of polypropylene polymer compositions cannot realize highly safe molded articles (battery components). Although Reference Example 1, which uses steel plates, has sufficient explosion-proof performance, it is inferior in moldability and also does not have sufficient heat insulation. In contrast, Examples 1-3, which contain (A) a polyolefin polymer, (B) a flame retardant, and (C) glass fibers, and have a mass ratio [(B) flame retardant content / (C) glass fiber content] of 0.5 or less, exhibited excellent moldability, allowing for the production of specified molded articles by various molding methods, not just injection molding, while demonstrating high explosion resistance in the UL2596 BETR test, with no damage to the test specimens. Moreover, they also exhibit high thermal insulation and self-extinguishing properties. Therefore, it can be seen that the polyolefin polymer compositions of Examples 1-3 can be used to manufacture molded articles (especially battery components) that exhibit high safety and reliability.

Claims

1. (A) a polyolefin polymer, (B) a flame retardant, and (C) glass fiber, A polyolefin polymer composition in which the mass ratio of the content of (B) flame retardant to the content of (C) glass fibers [(B) flame retardant content / (C) glass fiber content] is 0.5 or less.

2. The polyolefin polymer composition according to claim 1, wherein the mass ratio [(B) content of flame retardant / (C) content of glass fiber] is 0.35 or less.

3. The polyolefin polymer composition according to claim 1, wherein the mass ratio [(B) content of flame retardant / (C) content of glass fiber] is 0.20 or more.

4. The polyolefin polymer composition according to claim 1, wherein the (A) polyolefin polymer comprises (A1-P) polypropylene polymer.

5. The polyolefin polymer composition according to claim 1, wherein the flame retardant (B) contains a phosphorus-containing flame retardant.

6. The polyolefin polymer composition according to claim 1, wherein the (C) glass fibers include short fibers.

7. The polyolefin polymer composition according to claim 1, wherein the (A) polyolefin polymer comprises (A2) an acid-modified polyolefin polymer.

8. When the total content of (A) polyolefin polymer, (B) flame retardant, and (C) glass fiber is 100% by mass, The content of the polyolefin polymer (A) is 20 to 49% by mass, The content of the flame retardant (B) is 10 to 18% by mass, The polyolefin polymer composition according to claim 1, wherein the content of (C) glass fibers is 41% by mass or more.

9. The polyolefin polymer composition according to claim 4, wherein when the total content of (A) polyolefin polymer, (B) flame retardant, and (C) glass fiber is 100% by mass, the content of (A1-P) polypropylene polymer is 25 to 42% by mass.

10. The polyolefin polymer composition according to claim 7, wherein when the total content of (A) polyolefin polymer, (B) flame retardant, and (C) glass fiber is 100% by mass, the content of (A2) acid-modified polyolefin polymer is 0.1 to 5.0% by mass.

11. The polyolefin polymer composition according to claim 1, which exhibits self-extinguishing properties equivalent to the V-0 judgment criterion in the vertical combustion test specified in UL94 when used as a test specimen with a thickness of 3 mm.

12. A molded article comprising the polyolefin polymer composition according to any one of claims 1 to 11.

13. The molded article according to claim 12, which is an injection-molded article.

14. The molded article according to claim 12, wherein the thickness is less than 10 mm.

15. The molded body according to claim 12, which, when used as a test specimen with a thickness of 3 mm, exhibits self-extinguishing properties equivalent to the V-0 judgment criterion in the vertical combustion test specified in UL94.

16. A molded body according to claim 12, used in a battery component or a peripheral component thereof.

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