Resin composition and molded article thereof

Abstract

This resin composition contains an olefin polymer A, fibers B, and 2,4-di-tert-butylphenol, wherein the ratio of the mass of 2,4-di-tert-butylphenol to the mass of the fibers B is 0.002% to 2.8%.

Description

Resin composition and its molded article

[0001] The present invention relates to a resin composition and its molded article.

[0002] Conventionally, resin compositions containing polyolefin polymers such as polypropylene and fibers such as glass fibers are known.

[0003] WO2014 / 157391

[0004] However, there is still room for improvement in the compatibility between the appearance and the fatigue strength after heat aging of the molded article obtained from the resin composition.

[0005] The present invention has been made in view of the above problems, and an object thereof is to provide a resin composition capable of achieving both good appearance and high fatigue strength after heat aging in a molded article.

[0006] [1] A resin composition comprising an olefin polymer A, a fiber B, and 2,4-di-tert-butylphenol, wherein the ratio of the mass of 2,4-di-tert-butylphenol to the mass of the fiber B is 0.002 to 2.8%. [2] The resin composition according to [1], wherein the olefin polymer A is a propylene polymer. [3] The resin composition according to [1], wherein the olefin polymer A is a propylene homopolymer and / or a heterophagic propylene polymer material. [4] The resin composition according to any one of [1] to [3], comprising 20 parts by mass or more of the olefin polymer A per 100 parts by mass of the resin composition. [5] The resin composition according to any one of [1] to [4], wherein the fiber B is a glass fiber. [6] The resin composition according to any one of [1] to [5], wherein the weight-average fiber length of the fiber B is 200 μm or more. [7] The resin composition according to any one of [1] to [6], comprising 20 to 50 parts by mass of the fiber B per 100 parts by mass of the resin composition. [8] The resin composition according to any one of [1] to [7], comprising 0.001 to 0.85 parts by mass of 2,4-di-tert-butylphenol per 100 parts by mass of the resin composition. [9] The resin composition according to any one of [1] to [8], further comprising an acid-modified olefin polymer D.

[10] A molded article of the resin composition according to any one of [1] to [9].

[0007] The present invention provides a resin composition that can achieve both a good appearance and high fatigue strength after thermal aging in a molded article.

[0008] Figure 1 is a schematic cross-sectional view showing an example of a twin-screw compounding extruder used for preparing resin compositions.

[0009] The embodiments of the present invention will be described in detail below. The present invention is not limited to the specific embodiments shown below.

[0010] Explanation of Terminology: In describing embodiments of the present invention, we will first explain the terms commonly used.

[0011] In this specification, "monomer unit" means a monomer-derived constituent unit (residue) contained in a polymer obtained by polymerizing monomers.

[0012] In this specification, "α-olefin" means an olefin containing a carbon chain consisting of three or more carbon atoms having a carbon-carbon double bond at the terminal end (α position).

[0013] In 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.

[0014] Intrinsic viscosity can be determined specifically by the "extrapolation method," which involves measuring the reduced viscosity at multiple concentrations using an Ubbelohde viscometer, plotting the reduced viscosity against the concentration, and extrapolating the concentration to zero. More specifically, intrinsic viscosity can be determined using the method described on page 491 of "Polymer Solutions, Polymer Experiments 11" (Kyoritsu Shuppan Co., Ltd., 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] In this specification, "melt flow rate (MFR)" means "melt mass flow rate," which is the melt flow rate measured in accordance with JIS K7210-1:2014 and K7210-2:2014 under conditions of a temperature of 230°C and a load of 2.16 kgf.

[0016] In this specification, unless otherwise specified, "%" means mass percentage and "parts" means "parts by mass".

[0017] (Resin Composition) The resin composition according to an embodiment of the present invention is a resin composition containing an olefin polymer A, a fiber B, and 2,4-di-tert-butylphenol, wherein the ratio of the mass of 2,4-di-tert-butylphenol to the mass of fiber B is 0.002 to 2.8%.

[0018] The following describes the components that may be included in the resin composition of this embodiment.

[0019] (Olefin Polymer A) Olefin polymer A is a polymer that, when the total amount of the polymer is 100% by mass, contains 50% by mass or more of structural units derived from olefins having 2 to 10 carbon atoms. Examples of olefins having 2 to 10 carbon atoms are ethylene, propylene, 1-butene, 4-methyl-1-pentene, 1-hexene, 1-octene, and 1-decene. Examples of olefin polymer A are ethylene polymers and propylene polymers, with propylene polymers being preferred.

[0020] (Ethylene-based polymers) Ethylene-based polymers are polymers that contain 50% by mass or more of structural units derived from ethylene when the total amount of the polymer is considered to be 100% by mass. Examples of ethylene-based polymers include ethylene homopolymers, copolymers of ethylene and α-olefins, and copolymers of ethylene and α-olefins substituted with alicyclic compounds.

[0021] An example of an ethylene homopolymer is one in which repeating ethylene units are randomly linked in a branched structure by high-pressure radical polymerization using a radical initiator, with a density of 910–935 kg / m³. ３ This is high-pressure low-density polyethylene (LDPE).

[0022] Examples of copolymers of ethylene and α-olefins include crystalline linear low-density polyethylene and elastomers of copolymers of ethylene and α-olefins that have low crystallinity and rubbery elastic properties.

[0023] The density of linear low-density polyethylene is 900–940 kg / m³. ３ The density of the ethylene-α-olefin copolymer elastomer can be 860-900 kg / m³. ３ It can be.

[0024] Examples of α-olefins are α-olefins having 3 to 10 carbon atoms. 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. Preferably, the α-olefin has 4 to 10 carbon atoms, and more preferably, 1-butene, 1-hexene, or 1-octene.

[0025] An example of an α-olefin substituted with an alicyclic compound is vinylcyclohexane.

[0026] The amount of structural units derived from α-olefins in the ethylene polymer can be 4.0 to 20% by mass.

[0027] Specific 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. These may be used individually or as mixtures of two or more types. Furthermore, the ethylene-based polymer may be a mixture of an ethylene homopolymer and a copolymer of ethylene and α-olefins.

[0028] The melt flow rate of the ethylene polymer, measured at a measurement temperature of 190°C and under a load of 2.16 kg, 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.

[0029] Ethylene-based polymers can be produced using known polymerization catalysts and known polymerization methods.

[0030] 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. Furthermore, prepolymerization catalyst systems prepared by prepolymerizing ethylene or α-olefins in the presence of the above catalyst systems are also included. In addition, high-pressure low-density polyethylene (LDPE) can be produced using a radical initiator as a polymerization catalyst.

[0031] (Propylene polymers) Propylene polymers are polymers that contain more than 50% by mass of propylene units relative to the total constituent units (100% by mass). The amount of propylene units in propylene polymers is usually 100% by mass or less.

[0032] Examples of propylene-based 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.

[0033] Other monomers that can copolymerize with propylene include olefins other than propylene (e.g., ethylene, olefins with four or more carbon atoms). The number of carbon atoms in the olefin may be 12 or less.

[0034] Olefins having four or more carbon atoms may be linear or branched. Olefins having four or more carbon atoms may also be cyclic olefins, such as α-olefins having a cyclic structure, such as vinylcyclopropane and vinylcyclobutane.

[0035] Examples of olefins other than propylene that can copolymerize with propylene include α-olefins other than propylene (e.g., ethylene, 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 1-octene, and 1-decene). Preferably, the olefins other than propylene that can copolymerize with propylene are ethylene, propylene, 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 1-octene, and 1-decene, and more preferably ethylene, propylene, 1-butene, 1-hexene, and 1-octene.

[0036] (Propylene-based random copolymers) Examples of propylene-based random copolymers include random copolymers containing propylene units and ethylene units (hereinafter also referred to as random polymer (1)); random copolymers containing propylene units and α-olefin units having 4 or more carbon atoms (hereinafter also referred to as random polymer (2)); and random copolymers containing propylene units, ethylene units, and α-olefin units having 4 or more carbon atoms (hereinafter also referred to as random polymer (3)).

[0037] α-olefins having four or more carbon atoms that can constitute a propylene-based random copolymer are preferably α-olefins having four to ten carbon atoms. Examples of α-olefins having four to ten 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.

[0038] 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.

[0039] Examples of the random copolymer (3) include a propylene-ethylene-1-butene copolymer, a propylene-ethylene-1-hexene copolymer, a propylene-ethylene-1-octene copolymer, and a propylene-ethylene-1-decene copolymer.

[0040] The content of ethylene units in the random copolymer (1) is preferably 0.1 to 40% by mass.

[0041] The content of α-olefin units having 4 or more carbon atoms in the random copolymer (2) is preferably 0.1 to 40% by mass, more preferably 0.1 to 30% by mass, and still more preferably 2 to 15% by mass.

[0042] The total content of ethylene units and α-olefin units having 4 or more carbon atoms in the random copolymer (3) is preferably 0.1 to 40% by mass, more preferably 0.1 to 30% by mass, and still more preferably 2 to 15% by mass.

[0043] The content of propylene units in these random copolymers (1) to (3) is preferably 60 to 99.9% by mass, respectively.

[0044] The propylene-based polymer can be produced, for example, by the following polymerization method using a polymerization catalyst.

[0045] 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 or α-olefins in the presence of such catalyst systems may be used. An example of a Ziegler-Natta-type catalyst system is a catalyst system that uses a combination of a titanium-containing solid transition metal component and an organometallic component.

[0046] 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, and Japanese Patent Publication No. 10-212319, and for heterophagic propylene polymer materials, the catalyst system described in Japanese Patent Publication No. 2004-182981.

[0047] Examples of polymerization methods include bulk polymerization, solution polymerization, and gas-phase polymerization. Here, bulk polymerization refers to a method in which polymerization is carried out using liquid olefins at the polymerization temperature as a medium. Solution polymerization refers to a method in which polymerization is carried out in an inert hydrocarbon solvent such as propane, butane, isobutane, pentane, hexane, heptane, and octane. Gas-phase polymerization refers to a method in which a monomer in a gaseous state is used as a medium to polymerize a monomer in a gaseous state within that medium.

[0048] Examples of polymerization methods include batch, continuous, and combinations thereof. The polymerization method may also be a multi-stage method using multiple polymerization reactors connected in series.

[0049] 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 propylene polymer.

[0050] In the production of propylene polymers, the obtained propylene polymer may be treated to remove residual solvents and ultra-low molecular weight oligomers produced as by-products during production by holding it at a temperature at which residual solvents and impurities such as oligomers can volatilize, and at a temperature lower than the melting point of the propylene polymer. Examples of methods for removing residual solvents and impurities such as oligomers are described in Japanese Patent Publication No. 55-75410 and Japanese Patent No. 2565753.

[0051] From the viewpoint of improving the fluidity of the resin composition when melted and the toughness of the molded article formed from the resin 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.

[0052] Furthermore, the molecular weight distribution Mw / Mn of the propylene homopolymer is preferably 2 or more and less than 10, more preferably 3 to 8, and even more preferably 3 to 6, from the viewpoint of improving the fluidity of the resin composition during melting and the toughness of the molded article containing the resin composition. 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 (GPC).

[0053] The resin composition of this embodiment may contain two or more propylene polymers as the olefin polymer A.

[0054] Examples of combinations of two or more propylene polymers when two or more propylene polymers are included include combinations of two or more propylene homopolymers with different weight-average molecular weights, and heterophagic propylene polymer materials. The olefin polymer A is preferably a propylene homopolymer and / or a heterophagic propylene polymer material.

[0055] (Heterophasic propylene polymer material) Here, "heterophasic propylene polymer material" means a material that contains two or more propylene polymers, in which the two or more propylene polymers are miscible and form separate phases from each other.

[0056] Examples of heterophagic propylene polymer materials include materials containing combinations of polymer (I) and polymer (II) described below.

[0057] Here, polymer (I) is a polymer having propylene units in an amount exceeding 80% by mass and not exceeding 100% by mass relative to the total amount of constituent units. Polymer (I) may be a propylene homopolymer or a copolymer of propylene and other monomers. 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, when the mass of polymer (I) is taken as 100% by mass, and may be 0% by mass or 0.01% by mass or more.

[0058] Examples of monomer units other than propylene units that polymer (I) may have include ethylene units and α-olefin units having four or more carbon atoms.

[0059] The α-olefin having four or more carbon atoms that can constitute polymer (I) is preferably an α-olefin having four to ten carbon atoms, more preferably 1-butene, 1-hexene, and 1-octene, 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, propylene homopolymer, propylene-ethylene copolymer, propylene-1-butene copolymer, and propylene-ethylene-1-butene copolymer are preferred as polymer (I), and propylene homopolymer is more preferred from the viewpoint of improving the rigidity of the molded article formed from the resin composition.

[0062] Furthermore, 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 (II) is preferably a polymer having propylene units in an amount greater than 0% by mass and less than 90% by mass relative to the total amount of constituent units, and more preferably a polymer having propylene units greater than 0% by mass and less than 80% by mass. Polymer (II) may be a random copolymer or a block copolymer.

[0063] 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, when the mass of polymer (II) is 100% by mass.

[0064] The α-olefins having four or more carbon atoms that can constitute polymer (II) are preferably α-olefins having four to ten carbon atoms, and examples similar to those of α-olefins that can constitute polymer (I) described above can be given.

[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. Polymer (II) is preferably 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 polymer material 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, when the total mass of polymer (I) and polymer (II) is 100% by mass.

[0067] Polymer (I) and polymer (II) may each consist of only one type of polymer or may contain two or more types of polymers.

[0068] Examples of heterophagous propylene polymer materials include combinations of polymer (I) being a propylene homopolymer, such as a propylene homopolymer and a (propylene-ethylene) copolymer, a propylene homopolymer and a (propylene-ethylene-1-butene) copolymer, a propylene homopolymer and a (propylene-ethylene-1-hexene) copolymer, a propylene homopolymer and a (propylene-ethylene-1-octene) copolymer, a propylene homopolymer and a (propylene-1-butene) copolymer, a propylene homopolymer and a (propylene-1-hexene) copolymer, a propylene homopolymer and a (propylene-1-octene) copolymer, and a propylene homopolymer and a (propylene-1-decene) copolymer.

[0069] Furthermore, the heterophagic propylene polymer material may be a combination in which polymer (I) contains both propylene units and monomer units other than propylene units. If we describe the types of polymer (I) first and the types of polymer (II) second, specific examples of such heterophagic propylene polymer materials include: combinations of (propylene-ethylene) copolymer and (propylene-ethylene) copolymer, combinations of (propylene-ethylene) copolymer and (propylene-ethylene-1-butene) copolymer, combinations of (propylene-ethylene) copolymer and (propylene-ethylene-1-hexene) copolymer, combinations of (propylene-ethylene) copolymer and (propylene-ethylene-1-octene) copolymer, combinations of (propylene-ethylene) copolymer and (propylene-ethylene-1-decene) copolymer, combinations of (propylene-ethylene) copolymer and (propylene-1-butene) copolymer, combinations of (propylene-ethylene) copolymer and (propylene-1-hexene) copolymer, combinations of (propylene-ethylene) copolymer and (propylene-1-octene) copolymer, and (propylene-ethylene) copolymer. Combination of (propylene-1-decene) copolymer, combination of (propylene-1-butene) copolymer and (propylene-ethylene) copolymer, combination of (propylene-1-butene) copolymer and (propylene-ethylene-1-butene) copolymer, combination of (propylene-1-butene) copolymer and (propylene-ethylene-1-hexene) copolymer, combination of (propylene-1-butene) copolymer and (propylene-ethylene-1-octene) copolymer, (Pro Combinations of (propylene-1-butene) copolymer and (propylene-ethylene-1-decene) copolymer, combinations of (propylene-1-butene) copolymer and (propylene-1-butene) copolymer, combinations of (propylene-1-butene) copolymer and (propylene-1-hexene) copolymer, combinations of (propylene-1-butene) copolymer and (propylene-1-octene) copolymer, combinations of (propylene-1-butene) copolymer and (propylene-1-decene) copolymer,Examples include 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, and combinations of (propylene-1-octene) copolymer and (propylene-1-decene) copolymer.

[0070] The heterophagic propylene polymer materials that can be included in the resin composition of this embodiment are preferably combinations of propylene homopolymer and (propylene-ethylene) copolymer, propylene homopolymer and (propylene-ethylene-1-butene) copolymer, (propylene-ethylene) copolymer and (propylene-ethylene) copolymer, (propylene-ethylene) copolymer and (propylene-ethylene-1-butene) copolymer, and (propylene-1-butene) copolymer and (propylene-1-butene) copolymer, with the combination of propylene homopolymer and (propylene-ethylene) copolymer being more preferred.

[0071] Heterophasic propylene polymer materials can be produced by multi-stage polymerization, which includes a polymerization step to produce polymer (I) and a polymerization step to further produce polymer (II) while polymer (I) is still present. Polymerization can be carried out using the catalyst system exemplified as a catalyst usable for the production of the propylene polymer.

[0072] The olefin polymer A preferably contains one or more materials selected from the group consisting of propylene homopolymers and heterophagic propylene polymer materials.

[0073] Propylene polymers are １３The 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 of a propylene polymer is to 1, the higher the stereoregularity of the molecular structure of the propylene polymer and the higher the crystallinity of the propylene polymer. If the propylene polymer is a copolymer, the isotactic pentad fraction can be measured for the chain of propylene units in the copolymer.

[0074] From the viewpoint of improving the processability of the resin composition during molding, the propylene polymer preferably has a melt flow rate (MFR) of 0.1 g / 10 min or more, more preferably 0.5 g / 10 min or more, more preferably 500 g / 10 min or less, more preferably 400 g / 10 min or less, and preferably 0.1 g / 10 min to 500 g / 10 min, measured under conditions of a temperature of 230°C and a load of 2.16 kgf.

[0075] Furthermore, the intrinsic viscosity of the propylene polymer is typically 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, from the viewpoint of improving the fluidity and processability of the resin composition.

[0076] In this embodiment, the weight-average molecular weight of the propylene polymer in terms of polystyrene is usually 100,000 to 1,000,000, and preferably 500,000 to 1,000,000, from the viewpoint of improving the appearance and elongation properties of the molded article.

[0077] From the viewpoint of improving moldability and mechanical properties, the propylene polymer may have a molecular weight distribution (Mw / Mn) of 10 or less, and preferably 3 to 8.

[0078] 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.

[0079] When a propylene-based polymer is a polymer material consisting of polymer (I) and polymer (II) formed by multi-stage polymerization, a portion of polymer (I) prepared in the preceding polymerization can be withdrawn from the polymerization reactor to determine its intrinsic viscosity. The intrinsic viscosity (hereinafter referred to as ([η]Total)) of the propylene-based polymer finally obtained by multi-stage polymerization can then be determined. Using these intrinsic viscosity values ​​and the content of each polymer, the intrinsic viscosity of the polymer formed in the subsequent polymerization can be calculated.

[0080] Furthermore, if the polymer material consisting of polymer (I) and polymer (II) is manufactured by a method in which polymer (I) is obtained in the preceding polymerization step and polymer (II) is obtained in the subsequent polymerization step, the procedure for measuring and calculating the respective content of polymer (I) and polymer (II) and the intrinsic viscosity numbers ([η]Total, [η]I, [η]II) is as follows.

[0081] The intrinsic viscosity [η]II of polymer (II) can be calculated using the following formula from 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 polymer consisting of polymer (I) and polymer (II)) measured by the method described above, and the content of polymer (II) contained in the final polymer.

[0082] [η]II = ([η]Total - [η]I × XI) / XII [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 the final polymer Note that XI and XII can be determined from the mass balance during polymerization.

[0083] 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.

[0084] 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.

[0085] Furthermore, the ratio of [η]II to [η]I ([η]II / [η]I) is preferably 1 to 20, and more preferably 1 to 10.

[0086] The mass ratio XII of polymer (II) to the final polymer may also 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 (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)

[0087] Furthermore, the molecular weight distribution (Mw / Mn) of 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.

[0088] The olefin polymer A used in the present invention may contain one or more biomass-derived monomers. The polymer may consist solely of biomass-derived monomers, or it may contain both biomass-derived monomers and fossil fuel-derived monomers. Biomass-derived monomers are monomers made from any renewable natural raw materials and their residues, including fungi, yeasts, algae, and bacteria, which are plant-derived or animal-derived, and which contain carbon １４ 10 C isotopes －１２ If it is contained in a certain proportion and measured in accordance with ASTM D 6866, and the polymer production conditions such as the catalyst used and polymerization temperature are equivalent, then even if the raw material olefin contains biomass-derived olefin, １４ 10 C isotopes －１２ Aside from the small proportions it contains, its molecular structure is equivalent to that of olefin polymers composed of fossil fuel-derived monomers. Therefore, its performance is considered to be the same.

[0089] Furthermore, the olefin polymer A according to the present invention may also contain monomers derived from chemical recycling. The monomers constituting the polymer may consist solely of monomers derived from chemical recycling, or they may contain monomers derived from chemical recycling, monomers derived from fossil fuels, and / or monomers derived from biomass. Monomers derived from chemical recycling can be obtained by conventionally known methods. It is preferable for the olefin polymer A according to the present invention to contain monomers derived from chemical recycling from the viewpoint of reducing environmental impact (mainly waste reduction). Even if the raw material monomers contain monomers derived from chemical recycling, since monomers derived from chemical recycling are monomers obtained by depolymerizing polymers such as waste plastics, thermal decomposition, etc., back to monomer units such as propylene, and monomers produced using such monomers as raw materials, 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 an olefin polymer consisting of monomers derived from fossil fuels. Therefore, the performance is also considered to be unchanged.

[0090] (Content of olefin polymer A) The content of olefin polymer A in the resin composition of this embodiment is preferably 20 parts by mass or more, may be 30 parts by mass or more, may be 40 parts by mass or more, may be 50 parts by mass or more, may be 95 parts by mass or less, may be 90 parts by mass or less, may be 85 parts by mass or less, or may be 80 parts by mass or less, when the total mass of the resin composition is 100 parts by mass.

[0091] (Fiber B) There are no particular limitations on the material of fiber B. Examples of fiber B include glass fiber, carbon fiber, polyester fiber, polyamide fiber, polyurethane fiber, polyimide fiber, polyolefin fiber, polyacrylonitrile fiber, kenaf, cellulose fiber, etc. Among these, fiber B is preferably glass fiber. Glass fiber will be described first below.

[0092] (Glass Fibers) The material of the glass fibers 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 fibers, those manufactured by any manufacturing method can be used.

[0093] As the glass fiber, glass fiber obtained by cutting glass strands, known as chopped strands, may be used. Using chopped strands is preferable from the viewpoint of further enhancing the rigidity and impact strength of the molded product containing the resin composition. Commercially available glass fibers can be used.

[0094] The weight-average fiber diameter of the glass fiber may be 1 μm or more, and may be 50 μm or less. Preferably, the weight-average fiber diameter of the glass fiber is 3 μm or more, more preferably 6 μm or more, preferably 30 μm or less, and more preferably 20 μm or less.

[0095] The weight-average fiber length of the glass fiber is preferably 200 μm or more, may be 300 μm or more, may be 400 μm or more, and may be 500 μm or more. The weight-average fiber length of the glass fiber may be 10 mm or less, preferably 5 mm or less, more preferably 1.5 mm or less, even more preferably 1 mm or less, and particularly preferably 900 μm or less.

[0096] The aspect ratio (weight-average fiber length / weight-average fiber diameter) of the glass fiber may be 20 or more, and may be 120 or less. Preferably, the aspect ratio is 30 or more, more preferably 40 or more, preferably 100 or less, and more preferably 90 or less.

[0097] The weight-average fiber diameter, weight-average fiber length, and aspect ratio of glass fibers contained in a resin composition can be measured by the following method. 5 g of the resin composition is placed in a crucible and heated in an electric furnace under air at 600°C for 1 hour to obtain ash. Next, the glass fibers in the ash are observed using a microscope, and the length and diameter of 200 or more glass fibers are measured. The weight-average fiber length and weight-average fiber diameter are calculated using the measurement results, and the ratio of the weight-average fiber length to the weight-average fiber diameter is taken as the aspect ratio of the glass fibers contained in the resin composition. Here, the weight-average fiber length is the average value weighted by the measured individual fiber lengths, and is calculated by the following formula: (Weight-average fiber length) = Σ{Li × Li} / Σ{Li} where Li is the measured individual fiber length, and Σ indicates that the sum is taken over all measured fibers. The weight-average fiber length is also called the length-average fiber length because, for fibers with a constant fiber diameter, its length and weight are proportional. Weight-average fiber diameter, like weight-average fiber length, is a weighted average value based on the diameter of individual fibers. Weight-average fiber diameter, weight-average fiber length, and aspect ratio may also be determined from frequency distributions obtained by methods such as image analysis.

[0098] The glass fibers contained in the resin composition may be a combination of two or more types in any ratio. Therefore, as the glass fibers used as raw materials for the resin composition, one type of glass fiber may be used, or a combination of two or more types in any ratio may be used.

[0099] (Adjustment of glass fiber length and aspect ratio) Examples of methods for adjusting the glass fibers contained in a resin composition to a specific aspect ratio or weight-average fiber length range include appropriately adjusting the supply position of the glass fibers to the extruder when the raw materials are kneaded in the extruder; the temperature of the extruder; the screw rotation speed; the melt flow rate of the olefin polymer used as a raw material; and the length (fiber length) and fiber diameter of the glass fibers used as a raw material.

[0100] The following is an example of a specific adjustment method. Figure 1 is a schematic cross-sectional view showing an example of a twin-screw compounding extruder for producing the resin composition of this embodiment.

[0101] The twin-screw compounding extruder 100 comprises a cylinder 101 and a screw 110 located inside the cylinder 101. The length of the screw 110 from the upstream end 111 to the downstream end 112 in the direction F1 of the resin flow to be compounded (i.e., the total length of the screw 110) is L.

[0102] The twin-screw compounding extruder 100 includes a main hopper 130 and a side feeder 140 for supplying raw materials into the cylinder 101. The main hopper 130 is attached to the cylinder 101 so as to supply the raw material M1 into the cylinder 101 at a distance L1 from the upstream end 111 of the screw 110. The side feeder 140 is attached to the cylinder 101 so as to supply glass fibers GF into the cylinder 101 at a distance L2 from the upstream end 111 of the screw 110. Preferably, the supply position of the glass fibers is adjusted so that L2 / L is in the range of 0.3 to 0.9.

[0103] Here, typically, the components of the resin composition, excluding the glass fibers, are supplied into the cylinder 101 at a distance L1 from the end 111 on the upstream side of the screw 110. L1 is preferably 0 or greater and less than 0.3.

[0104] L2 / L is more preferably 0.5 or more, even more preferably 0.6 or more, even more preferably 0.5 to 0.9, and even more preferably 0.6 to 0.9. Generally, decreasing L2 / L can decrease the aspect ratio of the glass fibers contained in the resin composition, and increasing L2 / L can increase the aspect ratio.

[0105] Generally, increasing the extruder temperature during the production of the resin composition can increase the aspect ratio and 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. Generally, increasing the melt flow rate of the olefin polymer used as a raw material can increase the aspect ratio and fiber length.

[0106] Resin pellets containing glass fibers (glass fiber-containing resin pellets) may be used as the raw material for glass fibers supplied to the extruder. In such glass fiber-containing pellets, the length of the glass fibers (fiber length) usually roughly matches the length in the extrusion direction of the resin pellet. Glass fiber-containing resin pellets can be manufactured by any known method.

[0107] 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 bundle of glass fibers. The resin-impregnated bundle of glass fibers is usually cooled and cut with a pelletizer to obtain glass fiber-containing resin pellets. The glass fiber content in the glass fiber-containing resin pellets is preferably 50 to 99.9% by weight.

[0108] (Surface treatment of glass fibers) Glass fibers may be treated with a sizing agent and / or a surface treatment agent. From the viewpoint of improving dispersibility in olefin polymers (A), it is preferable that the glass fibers are surface-treated with a surface treatment agent. Examples of surface treatment agents include organosilane coupling agents, titanate coupling agents, aluminate coupling agents, zirconate coupling agents, silicone compounds, higher fatty acids, fatty acid metal salts, and fatty acid esters.

[0109] Examples of organosilane coupling agents include vinyltrimethoxysilane, γ-chloropropyltrimethoxysilane, γ-methacryloxypropyltrimethoxysilane, γ-aminopropyltrimethoxysilane, and 3-acryloxypropyltrimethoxysilane.

[0110] Examples of titanate coupling agents include isopropyltriisostearoyl titanate, isopropyltris(dioctyl pyrophosphate) titanate, and isopropyltri(N-aminoethyl) titanate.

[0111] An example of an aluminate coupling agent is acetalkoxyaluminum diisopropylate.

[0112] Examples of zirconate coupling agents include tetra(2,2-diallyloxymethyl)butyl, di(tridecyl)phosphite zirconate, and neopentyl(diallyl)oxytrineodecanoyl zirconate.

[0113] Examples of the silicone compounds include silicone oils and silicone resins. 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.

[0114] 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 nine or more carbon atoms (e.g., stearic acid, montanic acid). Among these, calcium stearate, aluminum stearate, calcium montanate, and sodium montanate are preferred.

[0115] 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. The amount of the surface treatment agent used is not particularly limited, but is preferably 0.01 to 5 parts by weight, more preferably 0.1 to 3 parts by weight, per 100 parts by weight of glass fiber.

[0116] The glass fibers may be treated with a sizing agent. Treatment with a sizing agent can cause the glass fibers to be 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 temperature of melt mixing with the olefin polymer A, and more preferably one that melts at 200°C or below.

[0117] (Content of Fiber B) The content of fiber B in the resin composition is preferably 20 parts by mass or more, and preferably 50 parts by mass or less, based on 100 parts by mass of the total amount of the resin composition. It may be 25 parts by mass or more, 30 parts by mass or more, 45 parts by mass or less, or 40 parts by mass or less.

[0118] The content of fiber B in the resin composition may be 20 parts by mass or more, 150 parts by mass or less, 25 parts by mass or more, 30 parts by mass or more, 120 parts by mass or less, or 100 parts by mass or less, per 100 parts by mass of olefin polymer A.

[0119] (2,4-di-tert-butylphenol) The resin composition of this embodiment contains 2,4-di-tert-butylphenol. The structural formula of 2,4-di-tert-butylphenol is shown below.

[0120]

[0121] In the resin composition, the ratio R of the mass of 2,4-di-tert-butylphenol to the mass of fiber B is 0.002 to 2.8%. This ratio R may be 0.005% or more, 0.01% or more, 0.02% or more, 0.05% or more, 0.1% or more, 0.2% or more, 0.5% or more, or 1.0% or more. This ratio R may be 2.7% or less, 2.6% or less, 2.5% or less, or 2.0% or less.

[0122] In the resin composition, the content of 2,4-di-tert-butylphenol when the total mass is 100 parts by mass may be 0.001 parts by mass or more, 0.002 parts by mass or more, 0.005 parts by mass or more, 0.01 parts by mass or more, 0.02 parts by mass or more, 0.05 parts by mass or more, 0.1 parts by mass or more, 0.2 parts by mass or more, 1.0 part by mass or less, 0.9 parts by mass or less, 0.85 parts by mass or less, 0.8 parts by mass or less, 0.7 parts by mass or less, or 0.5 parts by mass or less.

[0123] In this embodiment, the content of 2,4-di-tert-butylphenol is calculated based on the amount of raw materials used in the production of the resin composition. However, if the amount of raw materials used is unknown, it may be measured from the resin composition, for example, pellets or molded articles.

[0124] When measuring the 2,4-di-tert-butylphenol content from a resin composition, the content can be determined by the amount of 2,4-di-tert-butylphenol generated when a molded article, formed from the resin composition under the following injection molding conditions, is heated at 100°C for 15 minutes. Injection molding conditions: Cylinder temperature: 200°C, Mold temperature: 40°C, Filling pressure: 15 MPa, Holding pressure: 4.3 MPa, Holding pressure time: 40 seconds

[0125] More specifically, for example, the resin composition of this embodiment can be quantified by forming a 2g piece of a molded body by injection molding it using a conventionally known and suitable injection molding machine under the above injection molding conditions, and then heating the piece at 100°C for 15 minutes to generate 2,4-di-tert-butylphenol, which is then detected by gas chromatography using a conventionally known and suitable gas chromatograph measuring device.

[0126] (Acid-modified olefin polymer D) The resin composition of this embodiment may also contain acid-modified olefin polymer D in addition to olefin polymer A, fiber B, and 2,4-di-tert-butylphenol.

[0127] Here, acid-modified olefin polymer D refers to a polymer obtained by modifying a polyolefin polymer with an unsaturated carboxylic acid and / or an unsaturated carboxylic acid derivative.

[0128] Examples of acid-modified olefin polymers include acid-modified ethylene polymers and acid-modified propylene polymers.

[0129] Acid-modified ethylene polymers refer to polymers obtained by modifying ethylene polymers with unsaturated carboxylic acids and / or unsaturated carboxylic acid derivatives.

[0130] Acid-modified propylene polymers refer to polymers obtained by modifying propylene polymers with unsaturated carboxylic acids and / or unsaturated carboxylic acid derivatives.

[0131] The olefin polymers to be modified are homopolymers of one type of olefin or copolymers of two or more types of olefins. Examples of olefin polymers to be modified include ethylene polymers and propylene polymers.

[0132] The modified ethylene polymer is a polymer that contains more than 50% by weight of ethylene units relative to the total constituent units of the polymer, and the ethylene units in an ethylene polymer are usually 100% by weight or less.

[0133] The propylene polymer to be modified is a polymer containing more than 50% by weight of propylene units relative to the total constituent units of the polymer, and the amount of propylene units in a propylene polymer is usually 100% by weight or less. An example of a propylene polymer to be acid-modified is the propylene polymer exemplified in olefin polymer A.

[0134] Acid-modified propylene polymers are typically polymers having a substructure of a propylene polymer and a substructure derived from an unsaturated carboxylic acid and / or an unsaturated carboxylic acid derivative. Examples of acid-modified propylene polymers include (a) polymers obtained by graft polymerization of an unsaturated carboxylic acid and / or an unsaturated carboxylic acid derivative onto a propylene homopolymer; (b) polymers obtained by graft polymerization of an unsaturated carboxylic acid and / or an unsaturated carboxylic acid derivative onto a copolymer obtained by copolymerizing propylene with ethylene and one or more monomers selected from the group consisting of α-olefins having four or more carbon atoms; and (c) modified propylene polymers obtained by graft polymerization of an unsaturated carboxylic acid and / or an unsaturated carboxylic acid derivative onto a block copolymer obtained by homopolymerizing propylene and then copolymerizing with ethylene and one or more monomers selected from the group consisting of α-olefins having four or more carbon atoms.

[0135] The propylene polymer subjected to acid modification may be a single polymer or a combination of two or more polymers in any ratio. Therefore, the propylene polymer subjected to acid modification may be the aforementioned heterophagic propylene polymer material.

[0136] Examples of the aforementioned unsaturated carboxylic acids include maleic acid, fumaric acid, itaconic acid, acrylic acid, and methacrylic acid.

[0137] Examples of the aforementioned unsaturated carboxylic acid derivatives include acid anhydrides, ester compounds, amide compounds, imide compounds, and metal salts of unsaturated carboxylic acids. Specific 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.

[0138] Preferred unsaturated carboxylic acids are maleic acid and acrylic acid, and preferred unsaturated carboxylic acid derivatives are maleic anhydride and 2-hydroxyethyl methacrylate.

[0139] As acid-modified propylene polymers, polymers (b) and (c) described above are preferred. In one embodiment, the acid-modified propylene polymer is preferably a modified olefin polymer obtained by graft polymerization of maleic anhydride onto an olefin polymer containing more than 50% by weight of propylene units in the total constituent units.

[0140] The total content of unsaturated carboxylic acid units and unsaturated carboxylic acid derivative units in the acid-modified olefin polymer is preferably 0.1% to 20% by weight, and more preferably 0.1% to 10% by weight, based on 100% by weight of the acid-modified olefin polymer, from the viewpoint of rigidity and hardness of the molded article obtained from the resin composition. Here, if the acid-modified olefin 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.

[0141] 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.

[0142] The graft efficiency of the unsaturated carboxylic acid and / or unsaturated carboxylic acid derivative of the acid-modified olefin polymer is preferably 0.51 or higher, from the viewpoint of the rigidity and impact strength of the molded article obtained from the resin composition.

[0143] "Graft efficiency of acid-modified olefin 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 graft polymerization of unsaturated carboxylic acid and / or unsaturated carboxylic acid derivatives can be determined by the following procedure (1) to (9). (1) Dissolve 1.0 g of acid-modified olefin polymer in 100 ml of xylene; (2) Add the xylene solution dropwise to 1000 ml of methanol with stirring to reprecipitate the acid-modified olefin polymer; (3) Collect the reprecipitated acid-modified olefin polymer; (4) Vacuum dry the collected acid-modified olefin polymer at 80°C for 8 hours to obtain a purified acid-modified olefin polymer; (5) Hot press the purified acid-modified olefin polymer to prepare a film with a thickness of 100 μm; (6) Measure the infrared absorption spectrum of the film; (7) From the infrared absorption spectrum, quantify the absorption based on unsaturated carboxylic acid and / or unsaturated carboxylic acid derivatives and calculate the content (X1) of unsaturated carboxylic acid and / or unsaturated carboxylic acid derivatives that reacted with the olefin polymer in the acid-modified olefin polymer. (8) Separately, the acid-modified olefin polymer that has not undergone purification treatment is subjected to the above procedures (5) to (6), and the content of unsaturated carboxylic acid and / or unsaturated carboxylic acid derivatives (X2) in the acid-modified olefin polymer that has not undergone purification treatment is calculated from its infrared absorption spectrum. (X2) is the sum of the content of unsaturated carboxylic acid and / or unsaturated carboxylic acid derivatives that have reacted with the olefin polymer (X1) and the content of unsaturated carboxylic acid and / or unsaturated carboxylic acid derivatives that have not reacted with the olefin polymer (i.e., free); (9) The graft efficiency is calculated from the formula: graft efficiency = X1 / X2.

[0144] The MFR of the acid-modified propylene polymer is preferably 5 to 400 g / 10 min, more preferably 10 to 200 g / 10 min, and particularly preferably 20 to 200 g / 10 min, from the viewpoint of mechanical strength and production stability. The MFR is the value measured at 230°C and a load of 2.16 kgf in accordance with JIS K7210-1:2014 and K7210-2:2014.

[0145] (Additives) In addition to the components described above, the resin composition of this embodiment may also contain various additives as further optional components.

[0146] Examples of such optional additives include antioxidants, neutralizing agents, UV absorbers, light stabilizers, lubricants, antistatic agents, colorants (e.g., inorganic pigments, organic pigments), flame retardants, elastomers, antiblocking agents, processing aids, organic peroxides, pigment dispersants, foaming agents, foaming nucleating agents, plasticizers, crosslinking agents, crosslinking aids, brightness enhancers, antibacterial agents, light diffusing agents, and molecular weight modifiers.

[0147] The resin composition of this embodiment may contain these additives individually, or it may contain two or more arbitrary components in any ratio.

[0148] Among the additives, antioxidants, neutralizing agents, ultraviolet absorbers, light stabilizers, and colorants are particularly suitable. These will be explained in detail below. The resin composition of this embodiment preferably contains, in addition to the above components, one or more selected from the group consisting of organic peroxides, neutralizing agents, antioxidants, ultraviolet absorbers, light stabilizers, and colorants.

[0149] The resin composition may also contain other additives besides those already described, such as resins and rubber.

[0150] Examples of additives include polystyrenes (e.g., polystyrene, poly(p-methylstyrene), poly(α-methylstyrene), AS (acrylonitrile / styrene copolymer) resin), ABS (acrylonitrile / butadiene / styrene copolymer) resin, AAS (special acrylic rubber / acrylonitrile / styrene copolymer) resin, ACS (acrylonitrile / chlorinated polyethylene / styrene copolymer) resin, polychloroprene, chlorinated rubber, polyvinyl chloride, polyvinylidene chloride, acrylic resins, ethylene / vinyl alcohol copolymer resins, fluororesins, polyacetals, grafted polyphenylene ether resins and polyphenylene sulfide resins, poly Examples include thermoplastic resins such as urethane, polyamide, polyester resins (e.g., polyethylene terephthalate, polybutylene terephthalate), polycarbonate, polysulfone, polyether ether ketone, polyether sulfone, aromatic polyester resin, epoxy resin, diallyl phthalate prepolymer, silicone resin, silicone rubber, polybutadiene, 1,2-polybutadiene, polyisoprene, styrene / butadiene copolymer, butadiene / acrylonitrile copolymer, epichlorohydrin rubber, acrylic rubber, natural rubber, and PLA resin (polylactic acid) produced by polymerizing plant-derived monomers extracted from bio-raw materials.

[0151] (Modes of the resin composition) There are no particular limitations on the modes of the resin composition. For example, the resin composition may be in the form of a single pellet having the above composition, or in the form of a pulverized material, or in the form of flakes. The resin composition may also be a mixture of particles having different compositions. For example, it may be a mixture (dry blend) of pellet 1 containing olefin polymer A and 2,4-di-tert-butylphenol and pellet 2 containing olefin polymer A and fiber B.

[0152] (Method for producing the resin composition) The resin composition of this embodiment can be produced, for example, by melt-kneading the components already described. The temperature during melt-kneading may be 180°C or higher, 180 to 300°C, or 180 to 250°C.

[0153] Examples of melt kneading apparatus for the production of the resin composition of this embodiment include conventionally known and suitable Banbury mixers, single-screw extruders, twin-screw coaxial extruders, and twin-screw anomalous-direction extruders.

[0154] Specific examples of melting and mixing equipment include ZSK (registered trademark) manufactured by Coperion, TEM (registered trademark) manufactured by Toshiba Machine Co., Ltd., TEX (registered trademark) manufactured by Japan Steel Works, Ltd., KZW (registered trademark) manufactured by Technovel Co., Ltd., CMP (registered trademark) and TEX (registered trademark) manufactured by Japan Steel Works, Ltd., and FCM (registered trademark), NCM (registered trademark), and LCM (registered trademark) manufactured by Kobe Steel, Ltd.

[0155] The order in which the raw materials are mixed is not particularly limited. For example, all raw materials may be mixed together by putting them into the manufacturing apparatus at once, or some of the selected components may be mixed first, and then the resulting mixture may be mixed with the other components.

[0156] Alternatively, a resin composition may be produced by melt-kneading an intermediate composition α containing at least two components with other raw materials. For example, an intermediate composition α containing olefin polymer A1 and 2,4-di-tert-butylphenol may be melt-kneaded with an olefin polymer A2 that does not contain 2,4-di-tert-butylphenol. Here, olefin polymer A1 and olefin polymer A2 may be the same or different from each other. The intermediate composition α may further contain at least one of acid-modified olefin polymer D and an inorganic filler.

[0157] Intermediate composition α contains olefin polymer A and 2,4-di-tert-butylphenol, and the content of 2,4-di-tert-butylphenol may be greater than 1800 ppm by mass when the total mass of the intermediate composition is 100 parts by mass, and such material can be used as a masterbatch. Furthermore, at least one of the various components used as raw materials in the production of the olefin resin composition, such as olefin polymer A, fiber B, acid-modified olefin polymer D, and additives, may be recycled.

[0158] The properties of the olefin resin composition of this embodiment are not particularly limited. The olefin resin composition of this embodiment can be, for example, in the form of strands (filaments), sheets, plates, or pellets. The pellet shape can be produced, for example, by preparing a strand-shaped olefin resin composition and then cutting it to an appropriate length.

[0159] (Molded Article) The present invention also relates to a molded article obtained by molding the above-described resin composition. That is, the resin composition of this embodiment can be suitably used as a material for forming a molded article. The molded article can be obtained by molding the above-described resin composition by various molding methods. The shape and size of the molded article may be determined as appropriate.

[0160] The resin composition of this embodiment can be used, for example, as a material for molded articles such as automotive materials, home appliance materials, monitor materials, office automation equipment materials, medical materials, drain pans, toiletry materials, food packaging containers, bottles, containers, sheets, and films. The resin composition of this embodiment is less prone to static electricity and can suppress the adhesion of, for example, dirt, so it can preferably be applied to materials for vehicle-related components, home appliance materials, and food packaging containers such as retort pouches and microwaveable pouches.

[0161] The resin composition of this embodiment is particularly preferred for use as an injection molding material.

[0162] The following describes an example of using the resin composition of this embodiment as an injection molding material to produce an injection-molded article.

[0163] The injection-molded article is a molded article formed from the resin composition of this embodiment. Injection-molded articles generally exhibit excellent dimensional stability.

[0164] Injection-molded articles can be manufactured by any suitable conventional injection molding method. Examples of injection molding methods include 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.

[0165] The molded article (injection molded article) of this embodiment can be manufactured by the above method in any suitable shape and dimensions corresponding to the application.

[0166] Examples of material applications for injection-molded vehicle-related components include interior parts such as door trims, pillars, instrument panels, consoles, rocker panels, armrests, door panels, and spare tire covers; exterior parts such as bumpers, spoilers, fenders, and side steps; other components such as air intake ducts, coolant reserve tanks, fender liners, fans, and under deflectors; and integrally molded parts such as front end panels.

[0167] Examples of home appliance materials include materials for washing machines (outer tub, inner tub, lid, pulsator, balancer, etc.), dryers, vacuum cleaners, rice cookers, kettles, warmers, dishwashers, and air purifiers.

[0168] (Mechanism of Action) The resin composition according to this embodiment makes it possible to achieve both a good appearance and high fatigue strength after thermal aging in a molded article. The reason for this is not clear, but the following circumstances are considered possible. In this embodiment, since 2,4-di-tert-butylphenol is added to fiber B in a specific ratio, the adhesion between the fiber and the olefin polymer A is improved, and it is thought that high fatigue strength is achieved even after thermal aging. In addition, since there is not too much 2,4-di-tert-butylphenol, defects such as 2,4-di-tert-butylphenol bleeding on the surface of the molded article are suppressed.

[0169] The present invention will be described in more detail below with reference to examples. However, the present invention is not limited to these examples.

[0170] 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.

[0171] The components used in the examples and comparative examples are as follows: (1) Olefin polymer A (propylene homopolymer (A-1) and (A-x)) Using a polymerization catalyst obtained by the method described in Example 1 of Japanese Patent Application Publication No. 2004-182981, propylene homopolymers (A-1) and (A-x) were produced by gas-phase polymerization under conditions that yielded the following physical properties. (A-1) MFR: (230°C, load 2.16 kgf): 18 g / 10 min (A-x) MFR: (230°C, load 2.16 kgf): 100 g / 10 min

[0172] (Heterophasic propylene polymer material (A-2)) A heterophasic propylene polymer material (A-2) as an olefin polymer A was produced by liquid-phase-gas-phase polymerization using a polymerization catalyst obtained by the method described in Example 1 of Japanese Patent Application Publication No. 2004-182981, containing 79 parts by mass of (a) propylene homopolymer component as polymer (I) and 21 parts by mass of (b) propylene-ethylene random copolymer component as polymer (II). The physical properties were as follows: Melt flow rate (230°C, load 2.16 kgf): 27 g / 10 min (a) Intrinsic viscosity of propylene homopolymer component: 1.06 dL / g (b) Intrinsic viscosity of propylene-ethylene random copolymer: 2.8 dL / g Content of constituent units derived from ethylene: 33% by mass

[0173] (b) The content of ethylene-derived constituent units in the propylene-ethylene random copolymer was determined from the 13C-NMR spectrum measured under the following conditions, based on the report by Kakugo et al. (Macromolecules, 15, 1150-1152 (1982)). The 13C-NMR spectrum was measured using a sample prepared by uniformly dissolving approximately 200 mg of heterophagic propylene polymer material (A-2) in 3 mL of orthodichlorobenzene in a 10 mm diameter test tube, under the following conditions: Measurement temperature: 135°C Pulse repetition time: 10 seconds Pulse width: 45° Number of integrations: 2500

[0174] (2) Fiber B The following fibers were prepared.

[0175] Glass fiber (chopped strand) (B-1) Product name: CS-249A-10C (manufactured by Owens Corning) Weight-average fiber diameter: 10.5 μm Weight-average fiber length: 3.0 mm

[0176] (Glass fiber (B-2) (blended as glass long fiber PP pellets)) Product name: PG5003-3 (manufactured by Sumitomo Chemical Co., Ltd.) (Homo PP (A-x) / glass fiber = 50 / 50 parts by mass) Weight-average fiber diameter: 17 μm Weight-average fiber length: 9 mm

[0177] (Carbon Fiber (B-3)) Product Name: CFRIUT8S103CD0E (Manufactured by Carbon Fiber Recycling Industry Co., Ltd.) Weight-average fiber diameter: 6.0 μm Weight-average fiber length: 3.0 mm

[0178] (3) 2,4-di-tert-butylphenol 2,4-di-tert-butylphenol manufactured by Kanto Chemical Co., Ltd. was prepared.

[0179] (4) Acid-modified olefin polymer D (maleic anhydride-modified polypropylene (D-1)) Maleic anhydride-modified polypropylene (D-1) (hereinafter sometimes referred to as "acid-modified PP") was produced as acid-modified olefin polymer D in the following manner. 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). After thorough pre-mixing, the mixture was fed through the feed port of a twin-screw extruder and kneaded to obtain acid-modified PP (D-1). 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%.

[0180] [Evaluation] The evaluation was carried out according to the test method shown below. (1) Charpy impact test (unit: kJ / m2) Injection molding machine: A "M70" manufactured by Meiki Seisakusho Co., Ltd. was used, and injection molding was performed under the conditions of a molding temperature of 197°C and a mold cooling temperature of 38°C. A test piece with an ISO mold type A mold cavity shape was prepared, and the test piece was processed to a notch of 10 mm (width) x 80 mm (length) x 4 mm (thickness), and measured at a temperature of 23°C according to JIS K7111.

[0181] (2) Vibration fatigue characteristics after thermal aging (unit: cycles) Injection molding machine: An injection molding machine, "SE180DUZ" manufactured by Sumitomo Heavy Industries, Ltd., was used, and injection molding was performed under the conditions of a molding temperature of 210°C and a mold cooling temperature of 50°C to produce a JIS K7118 Type III test specimen. The prepared test specimen was placed in an oven at 150°C and removed after 25 hours. The test specimen removed from the oven was measured in accordance with the cantilever bending test method JIS K7119 under the following conditions, and evaluated based on the number of cycles until fracture. The more cycles until fracture, the better the fatigue strength. Test machine: Repeated vibration fatigue test machine (model B70TH) manufactured by Toyo Seiki Seisakusho Measurement temperature: 23°C Repetition rate: 30 Hz Load stress: 45 MPa

[0182] (3) Appearance (Appearance of injection-molded product) An injection molding machine: Using a Sumitomo Heavy Industries "SE130DU" injection molding machine, injection molding was performed using a resin composition obtained under the conditions of a molding temperature of 210°C and a mold cooling temperature of 50°C to produce a test plate measuring 150 mm (length) x 90 mm (width) x 2.0 mm (thickness). The appearance of the obtained test plate was observed visually and evaluated according to the following criteria. Good (○): No bleed or bubbles are observed on the surface of the test plate. Poor (×: Bleed): Bleed is observed on the surface of the test plate. Poor (×: Bubbles): Bubbles are observed on the surface of the test plate.

[0183] (4) Weight-average fiber diameter, weight-average fiber length, and aspect ratio of fibers in pellets 5 g of resin composition pellets were placed in a crucible and heated in an electric furnace at 600°C for 1 hour under air conditions to obtain ash. Next, the glass fibers in the ash were observed using a microscope, and the length and diameter of 200 or more glass fibers were measured. The weight-average fiber length and weight-average fiber diameter were calculated using the measurement results, and the ratio of the weight-average fiber length to the weight-average fiber diameter was defined as the aspect ratio of the glass fibers contained in the resin composition.

[0184] [Example 1] 69.0 parts by mass of propylene homopolymer (A-1), 1.0 part by mass of maleic anhydride-modified polypropylene (D-1), and 0.2 parts by mass of 2,4-di-tert-butylphenol were melt-kneaded in a twin-screw kneading extruder at a temperature of 200-230°C and a screw rotation speed of 400 rpm. Then, 30 parts by mass of glass fiber (B-1) were side-fed into the extruder midway, specifically at a position approximately 70% of the total screw length (L2 / L = 0.7). After passing through a chilled water bath, the strands were cut with a strand cutter to obtain pellets (corresponding to the resin composition). The obtained pellets were molded using each molding machine used in the above evaluation to produce injection-molded articles. Table 1 shows the mixing ratio of each component in the obtained resin composition.

[0185] [Examples 2, 3, 5, 8-11, Comparative Examples 1-5] Except for changing the blending materials and amounts of olefin polymer A, fiber B, 2,4-di-tert-butylphenol, and acid-modified olefin polymer D as shown in Table 1, pellets of the resin compositions of Examples 2-4, Example 6, Comparative Examples 1-4, and Reference Example 1 were obtained in the same manner as in Example 1, and injection molded articles of Examples 2, 3, 5, 8-11, Comparative Examples 1-5, and Reference Example 1 were manufactured.

[0186] [Example 4] In Example 4, a resin composition was obtained by dry blending 40.0 parts by mass of pellets of the resin composition obtained in Comparative Example 3 with 60.0 parts by mass of glass fiber pellets containing glass fiber (B-2). Table 1 shows the composition of each component of the resin composition of Example 4, which includes components derived from the resin composition of Comparative Example 3. The obtained pellets were molded using the molding machines used in the above evaluation to produce injection molded articles.

[0187] [Example 6]

[0188] [Preparation of Recycled Material α (Powdered Material from Example 2)] A test plate measuring 150 mm (length) x 90 mm (width) x 2.0 mm (thickness), obtained by molding the pellets obtained in Example 2, was crushed using a plastic crusher manufactured by Morita Seiki Kogyo Co., Ltd. to obtain Recycled Material α (Powdered Material from Example 2). Recycled Material α has the same composition as the resin composition of Example 2. Mesh size: φ6 mm

[0189] In Example 1, pellets of the resin composition of Example 6 were obtained in the same manner as in Example 1, except that 69 parts by mass of recycled material α, 30 parts by mass of glass fiber (B-1), 0.2 parts by mass of 2,4-di-tert-butylphenol, and 1 part by mass of maleic acid-modified polypropylene (D-1) were added, and injection molded articles of Example 6 were manufactured. The composition of each component of the resin composition of Example 6, including the component derived from recycled material α, is shown in Table 1. The composition and results are shown in Tables 1 and 2.

[0190]

[0191]

Claims

1. A resin composition comprising an olefin polymer A, a fiber B, and 2,4-di-tert-butylphenol, wherein the ratio of the mass of 2,4-di-tert-butylphenol to the mass of fiber B is 0.002 to 2.8%.

2. The resin composition according to claim 1, wherein the olefin polymer A is a propylene polymer.

3. The resin composition according to claim 1, wherein the olefin polymer A is a propylene homopolymer and / or a heterophagic propylene polymer material.

4. The resin composition according to claim 1, comprising 20 parts by mass or more of the olefin polymer A per 100 parts by mass of the resin composition.

5. The resin composition according to claim 1 or 2, wherein the fiber B is a glass fiber.

6. The resin composition according to claim 1 or 2, wherein the weight-average fiber length of fiber B is 200 μm or more.

7. The resin composition according to claim 1 or 2, comprising 20 to 50 parts by mass of the fiber B per 100 parts by mass of the resin composition.

8. The resin composition according to claim 1 or 2, comprising 0.001 to 0.85 parts by mass of 2,4-di-tert-butylphenol per 100 parts by mass of the resin composition.

9. The resin composition according to claim 1 or 2, further comprising an acid-modified olefin polymer D.

10. A molded article of the resin composition according to claim 1 or 2.

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