Polypropylene resin composition

Abstract

Provided is a polypropylene-based resin composition capable of improving the moist-heat resistance of a molded product.　The polypropylene-based resin composition includes: component (A) of a polypropylene-based polymer that is contained in an amount of 40-90 mass%; component (B) of an acid-modified polypropylene that is contained in an amount of 0.1-10 mass%; and component (C) of a glass fiber which has a water-soluble base component amount of at most 0.1 mmol / g, and a water-soluble weak acid salt content of at most 0.1 mmоl / g and which is contained in an amount of 10-60 mass%.

Description

Technical Field

[0001] The present invention relates to a polypropylene-based resin composition and a molded article thereof.

Background Art

[0002] Polyolefin-based resins obtained by polymerizing monomers mainly composed of olefins are excellent in molding processability and the like, and are thus used, for example, as materials for interior and exterior members for automobiles.

[0003] As a polyolefin-based resin composition assumed to be used as a material for interior and exterior members for automobiles and the like, for example, a polypropylene-based resin composition containing a polypropylene-based polymer and glass fibers is known (see Patent Document 1).

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] In recent years, there has been a study on applying resin parts to automobile parts, particularly parts inside an engine room, which are exposed to a high-temperature and high-humidity environment. However, the conventional polypropylene-based resin composition according to Patent Document 1 does not have sufficient moisture and heat resistance.

Means for Solving the Problems

[0006] As a result of intensive studies to solve the above problems, the present inventors have found that the above problems can be solved by including glass fibers satisfying predetermined parameters in a polypropylene-based resin composition, and have thus completed the present invention.

[0007] Therefore, the present invention provides the following [1] to [5]. [1] Component (A) Polypropylene polymer in 40-90% by mass, Component (B) Acid-modified polypropylene polymer in an amount of 0.1 to 10% by mass, Component (C) Glass fiber having a water-soluble base component content of 0.1 mmol / g or less and a water-soluble weak acid component content of 0.1 mmol / g or less, comprising 10 to 60% by mass. A polypropylene resin composition containing the following: [2] The polypropylene resin composition according to [1], wherein component (C) is a glass fiber having a total nitrogen content of 70 ppm or more as measured by chemiluminescence. [3] The polypropylene resin composition according to [1] or [2], wherein the melt flow rate measured under conditions of a temperature of 230°C and a load of 2.16 kgf is 1 to 20 g / 10 min. [4] The polypropylene resin composition according to any one of [1] to [3], wherein component (B) is an acid-modified polypropylene polymer in which the total amount of grafts of unsaturated carboxylic acid units and unsaturated carboxylic acid derivative units is 0.3% by mass or more, and the melt flow rate measured at a temperature of 230°C and a load of 2.16 kgf is 300 g / 10 min or less. [5] A polypropylene resin composition according to any one of [1] to [4], comprising 100 parts by mass of the total amount of component (A), component (B), and component (C), and further comprising 0.01 to 1 part by mass of component (D), a nucleating agent. A molded article containing a polypropylene resin composition as described in any one of [6][1] to [5]. An air intake manifold comprising a polypropylene resin composition described in any one of [7][1] to [5]. [Effects of the Invention]

[0008] The present invention provides a polypropylene resin composition that can improve the moisture-heat resistance (moisture-heat strength retention rate) of a molded article, and a molded article with improved moisture-heat resistance (moisture-heat strength retention rate). [Modes for carrying out the invention]

[0009] 1. Explanation of Terms In describing embodiments of the present invention, we will first explain the terms commonly used.

[0010] In this specification, "monomer unit" means a monomer-derived constituent unit (residue) contained in a polymer obtained by polymerizing monomers.

[0011] 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).

[0012] In this specification, the "intrinsic viscosity number (unit: dL / g)" is a value measured at a temperature of 135°C using tetralin as a solvent by the following method. The intrinsic viscosity can be determined 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, the intrinsic viscosity can be determined by using the method described on page 491 of "Polymer Solutions, Polymer Experiments 11" (Kyoritsu Shuppan Co., Ltd., 1982), 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.

[0013] In this specification, "melt flow rate (MFR)" means "melt mass flow rate" as defined in JIS K7210:1999.

[0014] In this specification, unless otherwise specified, "%" means mass%, and "parts" means parts by weight.

[0015] 2. Polypropylene resin composition The polypropylene resin composition of this embodiment will be described in detail below. The polypropylene-based resin composition of this embodiment contains 40 to 90% by mass of component (A) polypropylene-based polymer 0.1 to 10% by mass of component (B) acid-modified polypropylene-based polymer and 10 to 60% by mass of component (C) glass fiber with the amount of water-soluble basic component being 0.1 mmol / g or less and the amount of water-soluble weak acid salt being 0.1 mmol / g or less . The content of each of the above components is the value when the total amount of the polypropylene-based resin composition is 100% by mass

[0016] (Melt flow rate of polypropylene-based resin composition) The polypropylene-based resin composition of this embodiment preferably has a melt flow rate (at 230°C, load 2.16 kgf) of 1 g / 10 min or more, more preferably 2 g / 10 min or more, preferably 20 g / 10 min or less, more preferably 12 g / 10 min or less, and even more preferably 10 g / 10 min or less

[0017] If the melt flow rate of the polypropylene-based resin composition of this embodiment is as described above, the properties of the molded body formed from the polypropylene-based resin composition of this embodiment can be further improved, and in particular, both the strength (weld strength) and the wet heat resistance (wet heat strength retention rate) of the molded body can be achieved

[0018] (Use of polypropylene-based resin composition) By using the polypropylene-based resin composition of this embodiment, a molded body (particularly, an injection molded body) with excellent wet heat resistance can be produced

[0019] Therefore, the polypropylene-based resin composition (and its molded body) of this embodiment can be suitably applied, for example, as materials for interior and exterior parts for automobiles and engine room interior parts, parts for motorcycles, parts for electric products, various containers and their parts, furniture and their parts

[0020] The polypropylene resin composition of this embodiment is particularly suitable as a material for interior and exterior automotive parts and engine compartment parts that require excellent moisture and heat resistance and weather resistance. Examples of automotive interior and exterior parts include instrument panels, door trims, pillars, side protectors, console boxes, column covers, bumpers, fenders, and wheel covers. Examples of automotive engine compartment parts include battery cases, engine covers, and air intake manifolds. Examples of motorcycle parts include cowlings and muffler covers. Among these, the polypropylene resin composition of this embodiment is particularly suitable as a material for air intake manifolds used in the engine compartment of automobiles.

[0021] Here, we will specifically describe the components that the polypropylene resin composition of this embodiment may contain. (1) Component (A) Polypropylene polymer The amount of propylene units, which are monomer units, in polypropylene polymers is usually 100% by mass or less. A polypropylene polymer is a polymer in which, when the total amount of constituent units in a polypropylene polymer is taken as 100% by mass, propylene units make up more than 50% by mass.

[0022] Examples of polypropylene polymers include propylene homopolymers and copolymers of propylene and other monomers copolymerizable with propylene. Such copolymers may be random copolymers (hereinafter also referred to as polypropylene random copolymers) or block copolymers.

[0023] The polypropylene resin composition may contain one polypropylene polymer by itself, or it may contain two or more polypropylene polymers in any combination and proportion.

[0024] Examples of combinations of two or more polypropylene polymers include combinations of two or more propylene homopolymers with different weight-average molecular weights, and combinations of polymer (I) and polymer (II) described below.

[0025] The polypropylene resin composition may contain a heterophagic propylene polymerization material as the polypropylene polymer. Here, the heterophagic propylene polymerization material means a polypropylene polymer (composition) that contains the following polymer (I) and polymer (II), and in which polymer (I) and polymer (II) are miscible and form different phases from each other.

[0026] Here, polymer (I) is a polypropylene polymer containing more than 80% by mass and less than or equal to 100% by mass of propylene units, when the total amount of constituent units is taken as 100% by mass. Polymer (I) may be a propylene homopolymer or a copolymer of propylene and other monomers.

[0027] Furthermore, polymer (II) is a polypropylene polymer that 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.

[0028] Polymer (I) and polymer (II) may each be a single polymer or a combination of two or more polymers.

[0029] From the viewpoint of improving the rigidity and impact resistance of a molded article containing a resin composition, i.e., a molded article formed from a polypropylene resin composition, 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.

[0030] Polypropylene polymers are used to further improve the rigidity of molded articles containing polypropylene resin compositions. 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.

[0031] The closer the isotactic pentad fraction of a polypropylene polymer is to 1, the higher the stereoregularity of the molecular structure of the polypropylene polymer and the higher its crystallinity.

[0032] If the polypropylene polymer is a copolymer, the isotactic pentad fraction of the propylene unit chain in the copolymer can be measured.

[0033] From the viewpoint of improving the moldability of the polypropylene resin composition, the melt flow rate (MFR) of the polypropylene polymer, measured in accordance with JIS K7210 at 230°C and a load of 2.16 kgf, is preferably 1 g / 10 min or more, and more preferably 2 g / 10 min or more. The melt flow rate of the polypropylene polymer is preferably 200 g / 10 min or less, and more preferably 20 g / 10 min or less. In one embodiment, the melt flow rate of the polypropylene polymer is preferably 2 g / 10 min to 10 g / 10 min.

[0034] Polypropylene polymers can be produced, for example, by polymerization methods using polymerization catalysts.

[0035] Examples of polymerization catalysts include Ziegler-type catalysts, Ziegler-Natta-type catalysts, catalysts containing compounds having a cyclopentadienyl ring and a cyclopentadienyl ring that include a transition metal element from Group 4 of the periodic table, and alkylaluminoxanes, compounds having a cyclopentadienyl ring that include a transition metal element from Group 4 of the periodic table, compounds that react with such compounds to form ionic complexes, and catalysts containing organoaluminum compounds, as well as catalysts obtained by supporting and modifying catalyst components (e.g., compounds having a cyclopentadienyl ring that include a transition metal element from Group 4 of the periodic table, compounds that form ionic complexes, organoaluminum compounds, etc.) on inorganic particles (e.g., silica, clay minerals, etc.).

[0036] Furthermore, as a polymerization catalyst, a prepolymerization catalyst prepared by prepolymerizing monomers such as ethylene or α-olefins in the presence of the catalyst already described may be used.

[0037] An example of a Ziegler-Natta type catalyst is a catalyst that combines a titanium-containing solid transition metal component with an organometallic component.

[0038] Specific examples of the polymerization catalysts mentioned above include conventionally known catalysts described in Japanese Patent Publication No. 61-218606, Japanese Patent Publication No. 5-194685, Japanese Patent Publication No. 7-216017, Japanese Patent Publication No. 9-316147, Japanese Patent Publication No. 10-212319, and Japanese Patent Publication No. 2004-182981.

[0039] 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.

[0040] Examples of polymerization methods (polymerization schemes) in the above polymerization method include batch, continuous, and combinations thereof. The polymerization scheme may also be a multi-stage scheme using multiple polymerization reactors connected in series.

[0041] The various conditions in the polymerization process of the above polymerization method (polymerization temperature, polymerization pressure, monomer concentration, catalyst input amount, polymerization time, etc.) can be appropriately determined according to the target polypropylene polymer.

[0042] In producing polypropylene polymers, in order to remove residual solvents contained in the polypropylene polymer polymerized by the above polymerization method and impurities such as oligomers produced as by-products in the polymerization process, the polypropylene polymer polymerized by the above polymerization method may be held at a temperature at which residual solvents and other impurities such as oligomers can volatilize, and at a temperature at which the polypropylene polymer cannot melt, denature, etc. Examples of such impurity removal methods include conventionally known methods described in Japanese Patent Publication No. 55-75410, Japanese Patent No. 2565753, and others.

[0043] The following describes polypropylene-based polymers, including propylene homopolymers, polypropylene random copolymers, and heterophagic propylene polymerization materials.

[0044] (Propylene homopolymer) From the viewpoint of improving the fluidity of the polypropylene resin composition and the toughness of the molded article containing the polypropylene resin composition, the propylene homopolymer preferably has an intrinsic viscosity number [η] of 0.1 to 2 dL / g, more preferably 0.5 to 1.9 dL / g, and even more preferably 0.7 to 1.8 dL / g.

[0045] Furthermore, from the viewpoint of improving the fluidity of the polypropylene resin composition and the toughness of the molded article containing the polypropylene resin composition, the molecular weight distribution Mw / Mn of the propylene homopolymer is preferably 3 or more and less than 7, and more preferably 3 to 5. Here, Mw represents the weight-average molecular weight, and Mn represents the number-average molecular weight. The molecular weight distribution is a value measured by gel permeation chromatography (GPC).

[0046] (Polypropylene random copolymer) Examples of polypropylene-based random copolymers include random copolymers containing propylene units and ethylene units (hereinafter referred to as random copolymer (1)), random copolymers containing propylene units and α-olefin units having 4 or more carbon atoms (hereinafter referred to as random copolymer (2)), and random copolymers containing propylene units, ethylene units, and α-olefin units having 4 or more carbon atoms (hereinafter referred to as random copolymer (3)).

[0047] The α-olefins having 4 or more carbon atoms that can constitute a polypropylene-based random copolymer are preferably α-olefins having 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.

[0048] 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.

[0049] 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.

[0050] The ethylene unit content in the random copolymer (1) 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.

[0051] 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 even more preferably 2 to 15% by mass.

[0052] 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 even more preferably 2 to 15% by mass.

[0053] The propylene unit content in the random copolymers (1) to (3) 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.

[0054] (Heterophagic propylene polymerization material) As previously explained, the polymer (I) that may be included in the heterophagic propylene polymerization material is a polymer containing propylene units in amounts greater than 80% by mass and less than or equal to 100% by mass. 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, and may be 0% by mass or 0.01% by mass or more.

[0055] Examples of monomer units other than propylene units that polymer (I) may have include ethylene units and α-olefin units having 4 or more carbon atoms.

[0056] The α-olefins having 4 or more carbon atoms that can constitute polymer (I) are preferably α-olefins having 4 to 10 carbon atoms, more preferably 1-butene, 1-hexene, and 1-octene, and even more preferably 1-butene.

[0057] 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.

[0058] Among these, polymer (I) is preferably a propylene homopolymer, a propylene-ethylene copolymer, a propylene-1-butene copolymer, and a propylene-ethylene-1-butene copolymer, and more preferably a propylene homopolymer from the viewpoint of the rigidity of the molded article containing the polypropylene resin composition.

[0059] The molecular weight distribution (Mw / Mn) of polymer (I), as measured by GPC, is preferably 3 or more and less than 7, and more preferably 3 to 5.

[0060] As previously explained, polymer (II) is a copolymer of a propylene unit and at least one monomer unit selected from the group consisting of ethylene units and α-olefin units having 4 or more carbon atoms.

[0061] 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.

[0062] The α-olefins having 4 or more carbon atoms that can constitute polymer (II) are preferably α-olefins having 4 to 10 carbon atoms. Examples of α-olefins that can constitute polymer (II) are the same as those described above for α-olefins that can constitute polymer (I).

[0063] 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 propylene-ethylene copolymer, propylene-1-butene copolymer, and propylene-ethylene copolymer.

[0064] The content of polymer (II) in the heterophagic propylene polymerization material is preferably 1 to 50% by mass, more preferably 1 to 40% by mass, even more preferably 5 to 30% by mass, and particularly preferably 8 to 15% by mass, when the total of polymer (I) and polymer (II) is taken as 100% by mass.

[0065] Examples of heterophagous propylene polymerization 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.

[0066] Another example of a heterophagic propylene polymerization material is a polymer in which polymer (I) contains propylene units and monomer units other than propylene units, such as 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 (propylene-1-butene) copolymer, a combination of (propylene-ethylene) copolymer and (propylene-1-hexene) copolymer, a combination of (propylene-ethylene) copolymer and (propylene-1-octene) copolymer, and (propylene-ethylene A combination of (propylene-1-decene) copolymer and (propylene-1-decene) copolymer, a combination of (propylene-1-butene) copolymer and (propylene-ethylene) copolymer, a combination of (propylene-1-butene) copolymer and (propylene-ethylene-1-butene) copolymer, 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, ( 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. In the above examples of combinations, polymer (I) is listed first, followed by polymer (II).

[0067] The heterophagic propylene polymerization material that may be included in the polypropylene resin composition is 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.

[0068] The heterophagic propylene polymerization material can be produced by a multi-stage polymerization process that includes a first polymerization step for producing polymer (I) and a second polymerization step for producing polymer (II) in the presence of polymer (I) produced in the first polymerization step. The polymerization of the heterophagic propylene polymerization material can be carried out using catalysts exemplified as catalysts that can be used for the production of polypropylene-based polymers as described above.

[0069] The intrinsic viscosity number of polymer (I) (hereinafter referred to as [η]I) is preferably 0.1 to 2 dL / g, more preferably 0.5 to 1.5 dL / g, and even more preferably 0.7 to 1.3 dL / g.

[0070] The intrinsic viscosity number of polymer (II) (hereinafter referred to as [η]II) is preferably 1 to 10 dL / g, more preferably 2 to 10 dL / g, and even more preferably 5 to 8 dL / g.

[0071] Furthermore, the ratio of [η]II to [η]I ([η]II / [η]I) is preferably 1 to 20, more preferably 2 to 10, and even more preferably 2 to 9.

[0072] If the polypropylene polymer is a heterophagic propylene polymerization material consisting of polymer (I) and polymer (II) formed by the multi-stage polymerization process described above, the intrinsic viscosity number of polymer (I) produced in the first polymerization process is determined by taking a portion of it from the polymerization tank in which the first polymerization process was carried out. The intrinsic viscosity number (hereinafter referred to as ([η]Total)) of the heterophagic propylene polymerization material finally produced in the second polymerization process is then determined. Using these intrinsic viscosity numbers and their content, the intrinsic viscosity number of polymer (II) produced in the second polymerization process is calculated.

[0073] Furthermore, when a heterophagic propylene polymerization material consisting of polymer (I) and polymer (II) is produced by a manufacturing method in which polymer (I) is obtained in the first polymerization step and polymer (II) is obtained in the second polymerization step, the procedures for measuring and calculating the respective contents of polymer (I) and polymer (II), and the intrinsic viscosity numbers ([η]Total, [η]I, [η]II) are as follows.

[0074] The intrinsic viscosity number [η]II of polymer (II) is calculated using the following formula, based on the intrinsic viscosity number ([η]I) of polymer (I) obtained in the first polymerization step, the intrinsic viscosity number ([η]Total) of the final polymer obtained in the second polymerization step (i.e., the heterophagic propylene polymerization material consisting of polymer (I) and polymer (II)) measured by the method already described, and the content of polymer (II) contained in the final polymer. Formula: [η]II=([η]Total-[η]I×XI) / XII

[0075] During the ceremony, [η]Total represents the intrinsic viscosity number of the final polymer (unit: dL / g), [η]I represents the intrinsic viscosity number (unit: dL / g) of polymer (I), XI represents the weight ratio of polymer (I) to the final polymer. XII represents the weight ratio of polymer (II) to the final polymer. Furthermore, XI and XII can be determined from the mass balance in the polymerization process.

[0076] Here, the weight ratio XII of polymer (II) to the final polymer may be calculated using the following formula with the respective heats of fusion of polymer (I) and the final polymer. Equation: XII = 1 - (ΔHf)T / (ΔHf)P

[0077] During the ceremony, (ΔHf)T represents the heat of fusion (unit: cal / g) of the final polymer (polymer (I) and polymer (II)). (ΔHf)P represents the heat of fusion of polymer (I) (unit: cal / g).

[0078] (Content of component (A) polypropylene polymer) The content of component (A) polypropylene polymer in the polypropylene resin composition is 40 to 90% by mass, preferably 50% by mass or more, and preferably 80% by mass or less, when the total amount of the polypropylene resin composition is considered as 100% by mass.

[0079] (2) Component (B) Acid-modified polypropylene polymer The polypropylene resin composition of this embodiment includes, in addition to component (A) a polypropylene polymer, component (B) an acid-modified polypropylene polymer.

[0080] Here, an acid-modified polypropylene polymer refers to a polymer obtained by modifying a polypropylene polymer with an unsaturated carboxylic acid and / or an unsaturated carboxylic acid derivative.

[0081] The modified polypropylene polymer is a polymer containing propylene units in an amount greater than 50% by mass relative to the total constituent units of the polypropylene polymer. The amount of propylene units in a polypropylene polymer is usually 100% by mass or less. Examples of polypropylene polymers that are acid-modified include those already described in the explanation of component (A) polypropylene polymer.

[0082] Acid-modified polypropylene polymers are typically polymers that have a substructure of a polypropylene polymer and a substructure derived from an unsaturated carboxylic acid and / or an unsaturated carboxylic acid derivative.

[0083] Examples of acid-modified polypropylene polymers include (a) acid-modified polypropylene polymers obtained by graft polymerization of an unsaturated carboxylic acid and / or an unsaturated carboxylic acid derivative to a propylene homopolymer; (b) acid-modified polypropylene 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 monomers selected from the group consisting of α-olefins having 4 or more carbon atoms; and (c) acid-modified polypropylene polymers obtained by graft polymerization of an unsaturated carboxylic acid and / or an unsaturated carboxylic acid derivative to a heterophagic propylene polymerization material.

[0084] Acid-modified polypropylene polymers may be used as a single polymer or as a combination of two or more polymers in any ratio.

[0085] Examples of unsaturated carboxylic acids include maleic acid, fumaric acid, itaconic acid, acrylic acid, and methacrylic acid.

[0086] Examples of unsaturated carboxylic acid derivatives include acid anhydrides, ester compounds, amide compounds, imide compounds, and metal salts of unsaturated carboxylic acids.

[0087] 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.

[0088] Preferred unsaturated carboxylic acids are maleic acid and acrylic acid. Preferred unsaturated carboxylic acid derivatives are maleic anhydride and 2-hydroxyethyl methacrylate, with maleic anhydride being more preferred.

[0089] In other words, component (B) acid-modified polypropylene is preferably maleic acid-modified polypropylene, acrylic acid-modified polypropylene, maleic anhydride-modified polypropylene, or 2-hydroxyethyl methacrylate polypropylene.

[0090] The melt flow rate of the acid-modified polypropylene polymer is preferably 300 g / 10 min or less, more preferably 5 to 300 g / 10 min, even more preferably 10 to 200 g / 10 min, and even more preferably 20 to 170 g / 10 min, from the viewpoint of improving the heat resistance (heat resistance retention rate) of the molded article, as well as improving its strength (weld strength) and further improving the stability of the molded article's production.

[0091] As the acid-modified polypropylene polymer, the acid-modified polypropylene polymer described in (a) above is preferred.

[0092] The acid-modified polypropylene polymer is preferably an acid-modified polyolefin polymer obtained by graft polymerization of maleic anhydride onto a polyolefin polymer containing more than 50% by mass of propylene units in total constituent units.

[0093] From the viewpoint of improving the strength of the molded article formed from the polypropylene resin composition of this embodiment, the total amount of unsaturated carboxylic acid units and unsaturated carboxylic acid derivative units grafted into the acid-modified polypropylene polymer is preferably 0.1% to 20% by mass, more preferably 0.1% to 10% by mass, and even more preferably 0.3% to 10% by mass, when the amount of the acid-modified polypropylene polymer is 100% by mass. In one embodiment, the total amount of unsaturated carboxylic acid units and unsaturated carboxylic acid derivative units grafted into the acid-modified polypropylene polymer is preferably 0.2% to 1% by mass, and more preferably 0.3% to 0.6% by mass.

[0094] Here, if the acid-modified polypropylene polymer contains only one of either unsaturated carboxylic acid units or unsaturated carboxylic acid derivative units, the total graft amount of unsaturated carboxylic acid units and unsaturated carboxylic acid derivative units refers to the graft amount of only one of them.

[0095] Note that the graft amounts of unsaturated carboxylic acid units and unsaturated carboxylic acid derivative units refer to X1 as described later.

[0096] From the viewpoint of the strength (weld strength) of the molded article, it is preferable that the acid-modified polypropylene polymer has a total graft amount of unsaturated carboxylic acid units and unsaturated carboxylic acid derivative units of 0.3% by mass or more, and a melt flow rate of 300 g / 10 min or less, measured at a temperature of 230°C and a load of 2.16 kgf. In one embodiment, an acid-modified polypropylene is provided in which the graft amount of maleic anhydride units is 0.3% by mass or more, and a melt flow rate of 300 g / 10 min or less, measured at a temperature of 230°C and a load of 2.16 kgf.

[0097] The graft efficiency of the unsaturated carboxylic acid and / or unsaturated carboxylic acid derivative of the acid-modified polypropylene polymer is preferably 51% or higher, from the viewpoint of improving the rigidity and impact strength of the molded article formed from the polypropylene resin composition of this embodiment. The upper limit of the graft efficiency is 90% or less in one embodiment and 75% or less in another embodiment.

[0098] "Graft efficiency of acid-modified polypropylene polymers" refers to "the ratio of the amount of unsaturated carboxylic acids and / or unsaturated carboxylic acid derivatives chemically bonded to the acid-modified polypropylene polymer to the total amount of unsaturated carboxylic acids and / or unsaturated carboxylic acid derivatives not chemically bonded to the acid-modified polypropylene polymer."

[0099] The total amount X1 of unsaturated carboxylic acids and / or unsaturated carboxylic acid derivatives grafted into an acid-modified polypropylene polymer, and the graft efficiency, can be determined by the following procedure. (1) Mix 1.0 g of acid-modified polypropylene polymer with 100 mL of xylene and dissolve under reflux. (2) The obtained xylene solution is added dropwise to 300 mL of acetone while stirring to reprecipitate the acid-modified polypropylene polymer. (3) The reprecipitated acid-modified polypropylene polymer is recovered. (4) The recovered acid-modified polypropylene polymer is vacuum-dried at 70°C for 4 hours or more to obtain a purified acid-modified polypropylene polymer. (5) The purified acid-modified polypropylene polymer is heat-pressed to form a film with a thickness of approximately 100 μm. (6) Place 0.5 g of the formed film into 100 mL of xylene and dissolve under reflux. (7) Immediately add 1 to 2 drops of phenolphthalein indicator to the obtained xylene solution and titrate with a methanol solution of sodium hydroxide adjusted to 0.01 mol / L. The equivalence point A is defined as the midpoint between the light pink and dark pink of the solution.

[0100] Next, perform the blank test according to the following procedure. (8) Place 100 mL of xylene in a reflux apparatus and reflux for 1 hour. (9) Immediately add 1 to 2 drops of phenolphthalein indicator to the obtained xylene solution and titrate with the same sodium hydroxide methanol solution (0.01 mol / L) as above, and define the equivalence point A' as the midpoint between the light pink and dark pink of the solution.

[0101] Next, the amount X1 of unsaturated carboxylic acid and / or unsaturated carboxylic acid derivatives contained in the purified acid-modified polypropylene polymer is calculated according to the following formula (1) (the calculated X1 represents the content of unsaturated carboxylic acid and / or unsaturated carboxylic acid derivatives that have reacted with the polypropylene polymer, and is therefore referred to as the graft amount). Equation (1): Graft amount of unsaturated carboxylic acid and / or unsaturated carboxylic acid derivative X1 (mass%) = (0.00049 × (a - a') / W) × 100 In formula (1), 'a' represents the amount of liquid dispensed at equivalence point A (mL), a' represents the amount of liquid dispensed (mL) at the equivalence point A'. W represents the mass (g) of the film in step (6) above.

[0102] Next, the unpurified polypropylene polymer is subjected to the same treatment as in steps (5) to (9) above, and the content X2 of unsaturated carboxylic acids and / or unsaturated carboxylic acid derivatives in the unpurified acid-modified polypropylene polymer is calculated (X2 is the sum of the content of unsaturated carboxylic acids and / or unsaturated carboxylic acid derivatives that reacted with the polypropylene polymer (X1) and the content of unsaturated carboxylic acids and / or unsaturated carboxylic acid derivatives that did not react with the polypropylene polymer, i.e., free unsaturated carboxylic acids and / or unsaturated carboxylic acid derivatives).

[0103] (10) Apply the calculated X1 and X2 to the following formula to calculate the graft efficiency. Formula: Graft efficiency (%) = X1 / X2 × 100

[0104] (Content of component (B) acid-modified polypropylene polymer) The content of component (B) acid-modified polypropylene polymer in the polypropylene resin composition is 0.1 to 10% by mass, preferably 0.5% by mass or more, and preferably 5% by mass or less, when the total amount of the polypropylene resin composition is considered as 100% by mass.

[0105] (3) Component (C) Glass fiber In this embodiment, the amount of acidic functional groups in component (C) glass fiber is preferably less than 0.01 mmol / g from the viewpoint of improving the moisture-heat resistance (moisture-heat strength retention rate) of the molded article.

[0106] Here, we will explain the method for measuring the amount of acidic functional groups in glass fibers. The amount of acidic functional groups in glass fibers can be determined by conventionally known acid-base titration methods.

[0107] Specifically, for example, by first treating a sample of glass fibers that have been freeze-dried and pulverized with an aqueous sodium hydroxide solution, and then adding an aqueous hydrochloric acid solution dropwise to the supernatant liquid, the amount of acidic functional groups (mmol / g) in the sample can be calculated by performing a titration to detect the equivalence point based on the change in potential per drop (ΔE / ΔV).

[0108] More specifically, 1 g of freeze-dried and pulverized sample is mixed with 30 mL of sodium hydroxide aqueous solution (0.05 mol / L), shaken up and down for 4 hours using a shaker, and then left to stand for a while.

[0109] Subsequently, the obtained supernatant is filtered using a syringe filter, and 15 mL of the resulting filtrate is titrated by adding a 0.05 mol / L hydrochloric acid standard solution dropwise. The point at which the potential change per unit volume added (ΔE / ΔV) is maximum is defined as equivalence point A.

[0110] As a blank test, a 0.05 mol / L hydrochloric acid standard solution is added dropwise to 15 mL of sodium hydroxide aqueous solution (0.05 mol / L), and the point where the potential change per drop (ΔE / ΔV) is maximum is defined as equivalence point B.

[0111] The values ​​obtained as described above were calculated as the amount of acidic functional groups (mmol / g) using the following formula (2). Formula (2): Acidic functional group amount (mmоl / g) =(BA)×0.05×(30 / 15) / S In formula (2), A represents the titration volume (mL) of hydrochloric acid at equivalence point A. B represents the titration volume (mL) of hydrochloric acid at equivalence point B. S represents the mass (g) of the sample.

[0112] In this embodiment, component (C) glass fiber is a glass fiber having a water-soluble basic component content of 0.1 mmol / g or less and a water-soluble weak acid content of 0.1 mmol / g or less, from the viewpoint of improving the moisture and heat resistance of the molded article.

[0113] The amount of water-soluble basic component in the glass fiber is preferably 0.08 mmol / g or less, more preferably 0.05 mmol / g or less, and even more preferably 0.04 mmol / g or less.

[0114] Furthermore, the amount of water-soluble weak acid in the glass fiber is preferably 0.06 mmol / g or less, and more preferably 0.04 mmol / g or less.

[0115] Here, we will explain the method for measuring the amount of water-soluble basic components and water-soluble weak salts in glass fibers. The amount of water-soluble basic components and water-soluble weak acid salts in glass fibers can be measured in essentially the same way as the method for measuring the amount of acidic functional groups already described.

[0116] Specifically, first, the sample is prepared in the same manner as the method for measuring the amount of acidic functional groups. Next, the supernatant obtained by treating the sample with an aqueous hydrochloric acid solution is titrated by adding an aqueous sodium hydroxide solution dropwise, and the equivalence point is detected based on the change in potential per drop (ΔE / ΔV). This allows the amount of water-soluble basic components or water-soluble weak salts (mmol / g) in the sample to be calculated.

[0117] More specifically, 1 g of the freeze-dried and pulverized sample is mixed with 30 mL of hydrochloric acid solution (0.05 mol / L), shaken up and down for 4 hours using a shaker, and then left to stand for a while.

[0118] Subsequently, the obtained supernatant is filtered using a syringe filter, and a 0.05 mol / L sodium hydroxide aqueous solution is added dropwise to 15 mL of the resulting filtrate. The points where the potential change per drop (ΔE / ΔV) is maximum are designated as equivalence point C1 and equivalence point C2, starting from the point with the largest drop.

[0119] Furthermore, as a blank test, 0.05 mol / L sodium hydroxide solution is added dropwise to 15 mL of hydrochloric acid solution (0.05 mol / L), and the point where the potential change per drop (ΔE / ΔV) is maximum is defined as the equivalence point D.

[0120] Then, the amount of water-soluble basic component (mmol / g) was calculated using the following formula (3). Formula (3): Amount of water-soluble base component (mmol / g) =(d-c1)×0.05×(30 / 15) / S In formula (3), d represents the titration volume (mL) of the sodium hydroxide solution at the equivalence point D. c1 represents the titration volume (mL) of the sodium hydroxide aqueous solution at the equivalence point C1. S represents the mass (g) of the sample.

[0121] If only one equivalence point C appears in the titration procedure described above, the amount of water-soluble weak salt is 0 mmol / g. If two equivalence points C (equivalence points C1 and C2) appear, the amount of water-soluble weak salt (mmol / g) is calculated using the following formula (4). Formula (4): Amount of water-soluble weak acid salt (mmol / g) =(c1-c2)×0.05×(30 / 15) / S In formula (4), c1 represents the titration volume (mL) of the sodium hydroxide aqueous solution at the equivalence point C1. c2 represents the titration volume (mL) of the sodium hydroxide solution at the equivalence point C2 (where c1 > c2). S represents the mass (g) of the sample.

[0122] The amount of acidic functional groups, water-soluble basic components, and water-soluble weak salts in glass fibers can be measured, for example, using any suitable potentiometric automatic titrator known to date.

[0123] In this embodiment, the component (C) glass fiber is preferably a glass fiber having a total nitrogen content of 70 ppm or more, as measured by chemiluminescence, in order to further improve the strength (weld strength) of the molded article in addition to improving its moisture-heat resistance (moisture-heat strength retention rate).

[0124] Specifically, the total nitrogen content measured by the chemiluminescence method of glass fibers is preferably 70 ppm or more, more preferably 100 ppm or more, even more preferably 120 ppm or more, and particularly preferably 130 ppm or more.

[0125] Here, we will briefly explain the method for measuring the total nitrogen content of glass fibers using the chemiluminescence method. The total nitrogen content of glass fibers can be measured using any suitable analytical instrument that is conventionally known, in accordance with the method specified in JIS K 2609.

[0126] Specifically, the glass fiber sample is first heated under an inert gas atmosphere. This causes the nitrogen compounds in the sample to decompose thermally, generating nitric oxide gas. When this generated nitric oxide gas reacts with ozone, chemiluminescence occurs, and the intensity of this chemiluminescence is detected. The detected intensity of chemiluminescence is proportional to the nitric oxide concentration. Therefore, the total amount of nitrogen (ppm) in the sample can be calculated using a calibration curve based on a pre-prepared standard sample.

[0127] An example of an analytical instrument that can be used to measure the total nitrogen content of glass fibers is the TN-2100H trace total nitrogen analyzer (product name, manufactured by Nitto Seikou Analytech Co., Ltd.).

[0128] The fiber diameter of component (C) glass fiber contained in the polypropylene resin composition of this embodiment is not particularly limited, but is usually 3 to 25 μm. The fiber length of component (C) glass fiber is not particularly limited, but is usually 0.1 to 20 mm.

[0129] The component (C) glass fiber contained in the polypropylene resin composition may be a single type of glass fiber, or two or more types of glass fibers may be combined in any ratio.

[0130] The material for the glass fibers is not particularly limited, and any suitable glass known conventionally can be used as the material. Examples of glass fiber materials include E glass (alkali-free glass), A glass, C glass, S glass, and D glass. Among these, E glass is preferred as the material for the glass fibers. The method for manufacturing the glass fibers is not particularly limited, and glass fibers manufactured by any suitable manufacturing method known conventionally can be used as the glass fibers.

[0131] The glass fibers may be treated with a sizing agent and / or a surface treatment agent.

[0132] Glass fibers are preferably surface-treated with a surface treatment agent, from the viewpoint of improving dispersibility with component (A) polypropylene polymer. 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.

[0133] Examples of organosilane coupling agents include vinyltrimethoxysilane, γ-chloropropyltrimethoxysilane, γ-methacryloxypropyltrimethoxysilane, γ-aminopropyltrimethoxysilane, and 3-acryloxypropyltrimethoxysilane.

[0134] Examples of titanate coupling agents include isopropyltriisostearoyl titanate, isopropyltris(dioctyl pyrophosphate) titanate, and isopropyltri(N-aminoethyl) titanate.

[0135] An example of an aluminate coupling agent is acetalkoxyaluminum diisopropylate.

[0136] Examples of zirconate coupling agents include tetra(2,2-diallyloxymethyl)butyl, di(tridecyl)phosphite zirconate, and neopentyl(diallyl)oxytrineodecanoyl zirconate.

[0137] Examples of silicone compounds include silicone oils and silicone resins.

[0138] 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.

[0139] 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.

[0140] Examples of fatty acid esters include polyhydric alcohol fatty acid esters such as glycerol 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.

[0141] The amount of surface treatment agent used is not particularly limited. The amount of surface treatment agent used 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.

[0142] The glass fibers may be treated with a sizing agent. Treatment with a sizing agent can be used to bind the glass fibers together.

[0143] 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.

[0144] The sizing agent is preferably one that melts at the temperature during the manufacturing process of the polypropylene resin composition, and more preferably one that melts at 200°C or below.

[0145] As the glass fiber, so-called chopped strands obtained by cutting glass strands may be used. From the viewpoint of further improving the rigidity and impact strength of the molded article containing the polypropylene resin composition, it is preferable to use chopped strands as the glass fiber.

[0146] As glass fibers, resin pellets containing glass fibers (glass fiber-containing resin pellets) may be used. In such glass fiber-containing pellets, the length of the glass fibers (fiber length) usually roughly coincides with the length in the extrusion direction of the glass fiber-containing resin pellet.

[0147] Glass fiber-containing resin pellets can be manufactured using a conventionally known and suitable resin selected considering the composition of the polypropylene-based resin composition to be manufactured, and by a conventionally known and suitable manufacturing method.

[0148] Glass fiber-containing resin pellets can be manufactured, for example, by pultrusion. Pultrusion is a method in which bundles of glass fibers are impregnated into a resin by melt-extruding a conventionally known and suitable resin, which is the material for glass fiber-containing resin pellets, from an extruder while drawing out multiple continuous glass fibers, the impregnated bundles of glass fibers are cooled, and then cut by a pelletizer to integrate multiple bundles of glass fibers.

[0149] The glass fiber content in the glass fiber-containing resin pellets is preferably 50 to 99.9% by mass.

[0150] As for the glass fibers, commercially available glass fibers can be selected and used that have a water-soluble base component content of 0.1 mmol / g or less and a water-soluble weak acid content of 0.1 mmol / g or less. Specific examples of commercially available products include "CS-249A-10C" (product name, manufactured by Owens Corning Co., Ltd.) and "ECS10-03-508H" (product name, manufactured by Kyoseki JAPAN Co., Ltd.).

[0151] The content of component (C) glass fiber in the polypropylene resin composition is 10 to 60% by mass, preferably 15% by mass or more, more preferably 25% by mass or more, and preferably 55% by mass or less, when the total amount of the polypropylene resin composition is considered as 100% by mass.

[0152] (4) Component (D) Nucleoforming agent The polypropylene resin composition of this embodiment may further contain component (D), a nucleating agent, in addition to the above components (A) to (C). By including component (D), a nucleating agent, the polypropylene resin composition can increase its weld strength.

[0153] Any conventionally known and suitable nucleating agent can be used. Examples of nucleating agents include sorbitol-based nucleating agents, phosphate ester metal salt-based nucleating agents, carboxylate metal salt-based nucleating agents, and rosin-based nucleating agents. An example of a carboxylate metal salt-based nucleating agent is aluminum hydroxy-di(p-tert-butylbenzoate).

[0154] As a nucleating agent, aluminum hydroxy-di(p-tert-butylbenzoate) can be used, for example, the commercially available "AL-PTBBA" manufactured by Japan Chemtec Co., Ltd. can be used.

[0155] The amount of component (D) nucleating agent added is preferably 0.01 parts by mass or more, more preferably 0.05 parts by mass or more, preferably 3 parts by mass or less, more preferably 1 part by mass or less, and preferably 0.05 to 1 part by mass, relative to 100 parts by mass of the total amount of components (A) to (C) described above.

[0156] (5) Optional ingredients The polypropylene resin composition of this embodiment may contain further optional components in addition to the components (A) to (C) already described and the optional component (D).

[0157] Examples of such optional components include flame retardants, 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.

[0158] The polypropylene resin composition of this embodiment may contain one of these optional components alone, or it may contain two or more optional components in any ratio.

[0159] Examples of optional flame retardants that may be included in polypropylene resin compositions include metal oxides, polyvalent hydroxyl group-containing compounds, and phosphorus-containing flame retardants.

[0160] 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, and calcium oxide are preferred metal oxides, with zinc oxide being more preferred. The metal oxides may be surface-treated.

[0161] 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.).

[0162] 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 degree of condensation of 4 or more, 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.

[0163] Examples of elastomers that may be included in polypropylene resin compositions include random copolymers having ethylene units and α-olefin units with 4 to 10 carbon atoms. The melt flow rate of such random copolymers, measured in accordance with JIS K7210 at 230°C and a load of 2.16 kgf, is preferably 0.1 to 50 g / 10 min.

[0164] Examples of α-olefins having 4 to 10 carbon atoms that constitute the random copolymer, which is an elastomer, include α-olefins having 4 to 10 carbon atoms similar to those that can constitute the polypropylene polymer (component A). Specific examples of α-olefins include α-olefins having a chain structure such as 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 1-octene, and 1-decene, and α-olefins having a cyclic structure such as vinylcyclopropane and vinylcyclobutane. 1-butene, 1-hexene, and 1-octene are preferred as α-olefins.

[0165] Examples of 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 with α-olefins having a cyclic structure.

[0166] The α-olefin content in the 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, when the weight of the random copolymer is 100% by mass.

[0167] From the viewpoint of improving the impact resistance of the molded product, 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.

[0168] Random copolymers, which are elastomers, can be produced by polymerizing monomers using a polymerization catalyst. Examples of polymerization catalysts include those previously described as examples of polymerization catalysts for producing polypropylene polymers.

[0169] Commercially available products may be used as random copolymers. Examples of commercially available elastomer random copolymers include Engage® manufactured by Dow Chemical Japan Ltd., Tuffmer® manufactured by Mitsui Chemicals, Inc., Neozex® and Ultzex® manufactured by Prime Polymer Co., Ltd., and Excellen FX®, Sumikasen® and Esprene SPO® manufactured by Sumitomo Chemical Co., Ltd.

[0170] The amount of elastomer added is preferably 0 to 100 parts by mass, and more preferably 0 to 50 parts by mass, relative to 100 parts by mass of the total amount of components (A) to (C) described above.

[0171] A molecular weight modifier is a component that can adjust the molecular weight of component (A) polypropylene polymer in a polypropylene resin composition. Examples of molecular weight modifiers include organic peroxides. As the molecular weight modifier, a molecular weight modifier in the form of a so-called masterbatch, diluted with any conventionally known resin, may be used.

[0172] 3. Method for producing polypropylene resin composition The polypropylene resin composition of this embodiment can be manufactured by any suitable conventional manufacturing method.

[0173] The polypropylene resin composition of this embodiment can be produced by kneading the previously described components (A) polypropylene polymer, component (B) acid-modified polypropylene polymer, and component (C) glass fiber, as well as any other previously described components that may be added as needed, using a conventionally known and suitable commercially available twin-screw kneading extruder equipped with a cylinder and two screws.

[0174] An example of a twin-screw extruder that can be used is a twin-screw extruder equipped with a side feeder.

[0175] In manufacturing the polypropylene resin composition of this embodiment, if a component is used that is easily deformed (easily broken) by kneading, such as component (B) glass fibers, and such deformation is undesirable, such component may be added to the twin-screw kneading extruder at a delayed timing by separately feeding it using a side feeder. In this way, for example, the breakage of glass fibers contained in the polypropylene resin composition can be suppressed, and good performance can be achieved.

[0176] 4. Molded articles (injection molded articles) and methods for manufacturing molded articles The molded article of this embodiment is preferably an injection-molded article, and contains the polypropylene resin composition of this embodiment as described above, and is a molded article formed from the polypropylene resin composition of this embodiment.

[0177] Since the molded article of this embodiment contains the polypropylene resin composition described above, it has excellent moisture and heat resistance (moisture and heat strength retention rate), and as previously described, it can be suitably used as a material for interior and exterior parts and engine compartment parts for automobiles.

[0178] Examples of methods for manufacturing the molded article according to this embodiment include, 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.

[0179] The shape and dimensions of the molded article in this embodiment are not particularly limited. The molded article (injection molded article) in this embodiment can be manufactured by the above manufacturing method in any suitable shape and dimensions corresponding to the applications already described.

[0180] 5. Physical properties of the molded product (1) Tensile strength The tensile strength of the molded article in this embodiment can be measured by a method compliant with JIS K7161 (details of the measurement method will be described later).

[0181] (2) Moisture-resistant heat strength retention The moisture and heat resistance retention rate of the molded article in this embodiment can be calculated by performing an accelerated degradation test in which the molded article is held under predetermined harsh conditions for a predetermined time, and comparing the initial tensile strength of the molded article with the tensile strength after the accelerated degradation test (details of the calculation method will be described later).

[0182] The moisture-resistant heat strength retention rate of the molded article of this embodiment is preferably 95% or more, and more preferably 98% or more.

[0183] (3) Weld tensile strength The weld tensile strength of the molded article in this embodiment can be measured using an evaluation dumbbell molded according to ASTM D635 (details of the measurement method will be described later).

[0184] [Examples] The present invention will be described in more detail below with reference to examples and comparative examples. The present invention is not limited in any way by the examples.

[0185] First, we will explain the components used in the examples (components (A), (B), (C), and (D)).

[0186] (1) Component (A) Polypropylene polymer The following components (A-1) and (A-2) were used as component (A). Ingredient (A-1): Propylene homopolymer "Sumitomo Noblen W101" (product name, manufactured by Sumitomo Chemical Co., Ltd.) (MFR (230℃, load 2.16kgf); 9g / 10min) Ingredient (A-2): Propylene homopolymer "Sumitomo Noblen U501E1" (product name, manufactured by Sumitomo Chemical Co., Ltd.) (MFR (230℃, load 2.16kgf); 100g / 10min)

[0187] (2) Component (B) Acid-modified polypropylene The following components (B-1) and (B-2) were used as component (B). Component (B-1): Acid-modified polypropylene polymer (maleic anhydride-modified polypropylene polymer) produced using a propylene homopolymer by the method described in Japanese Patent Publication No. 2002-256023. MFR (230°C, load 2.16 kgf): 170 (g / 10 min), maleic anhydride graft amount: 0.32 (mass%), graft efficiency: 64 (%) Ingredients (B-2) "Bondyram1001" (product name, manufactured by BYK Co., Ltd.), MFR (230℃, load 2.16kgf): 320 (g / 10 min), Maleic anhydride graft amount: 0.41 (mass%), Graft efficiency: 60 (%)

[0188] (3) Component (C) Glass fiber The components used as component (C) were (C-1), (C-2), and (C-3) listed below. The amount of acidic functional groups, water-soluble basic components, water-soluble weak acid salts, and total nitrogen of component (C) are also shown in Table 1 below. Ingredients (C-1): "CS-249A-10C" (product name, manufactured by Owens Corning Co., Ltd., chopped strand, fiber diameter: 10.5 μm, amount of acidic functional groups measured by the above acid-base titration method: less than 0.01 mmol / g, amount of water-soluble basic component: 0.04 mmol / g, amount of water-soluble weak acid salt: 0.04 mmol / g, total nitrogen amount measured by chemiluminescence: 140 ppm) Ingredients (C-2): "ECS10-03-508H" (product name, manufactured by Kyoseki JAPAN Co., Ltd., chopped strand, fiber diameter: 10.5 μm, amount of acidic functional groups measured by acid-base titration: less than 0.01 mmol / g, amount of water-soluble basic component: 0.03 mmol / g, amount of water-soluble weak acid salt: 0.02 mmol / g, total nitrogen amount measured by chemiluminescence: 70 ppm) Ingredients (C-3): "T480H" (product name, manufactured by Nippon Electric Glass Co., Ltd., chopped strand, fiber diameter: 10.5 μm, amount of acidic functional groups measured by acid-base titration: less than 0.01 mmol / g, amount of water-soluble basic component: 0.81 mmol / g, amount of water-soluble weak acid salt: 0.55 mmol / g, total nitrogen amount measured by chemiluminescence: 120 ppm)

[0189] [Table 1]

[0190] (4) Component (D) Nucleoforming agent As component (D), aluminum hydroxy-di(p-tert-butylbenzoate) (AL-PTBBA, manufactured by Japan Chemtech Co., Ltd.) was used.

[0191] The physical properties shown in the examples were measured as follows. (i) 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.

[0192] (ii) Tensile strength The tensile strength was measured in accordance with JIS K7161 at a measurement ambient temperature of 23°C and a tensile speed of 5 mm / min. The test specimens were formed by injection molding of ISO multipurpose test specimen type A, and then conditioned by standing in an atmosphere of 23°C and 50% humidity for 48 hours before use. Here, "tensile strength" is used as "initial tensile strength" in the calculation of formula (10) for the moisture and heat strength retention rate in (iii) below.

[0193] (iii) Moisture-resistant thermal strength retention ISO multipurpose test specimens of type A, molded by injection molding, were exposed to constant temperature conditions at 80°C and 95% humidity for 2000 hours. After removal, they were allowed to settle at 23°C and 50% humidity for 24 hours for conditioning. Subsequently, according to the method specified in JIS K7161, the tensile strength after treatment (after 2000 hours) was measured at a measurement ambient temperature of 23°C and a tensile speed of 5 mm / min, and the moisture and heat resistance retention rate was calculated using the following formula (10). Formula (10): Moisture and heat resistance retention rate (%) = 100 × Tensile strength after treatment (after 2000 hours) / Initial tensile strength

[0194] (iv) Weld tensile strength During the molding of the ASTMD635Type1 dumbbell, the polypropylene resin composition of the present invention was filled from two points on both ends of the dumbbell shape. Using a test piece formed by injection molding so that a weld line was created in the center of the parallel section of the molded ASTMD635Type1 dumbbell, the weld tensile strength was measured at a tensile speed of 10 mm / min in a measurement ambient temperature of 23°C.

[0195] (v) Acidic functional group amount The amount of acidic functional groups in component (C) glass fiber was determined by the following acid-base titration method. Specifically, 1 g of the freeze-dried sample (component (C-1), component (C-2), or component (C-3)) was first mixed with 30 mL of sodium hydroxide aqueous solution (0.05 mol / L), shaken up and down for 4 hours using a shaker, and then left to stand for a while.

[0196] Subsequently, the obtained supernatant was filtered using a syringe filter, and 15 mL of the resulting filtrate was titrated by adding a 0.05 mol / L hydrochloric acid standard solution dropwise. The point at which the potential change per unit volume added (ΔE / ΔV) was maximum was defined as equivalence point A.

[0197] As a blank test, a 0.05 mol / L hydrochloric acid standard solution was added dropwise to 15 mL of sodium hydroxide aqueous solution (0.05 mol / L), and the point where the potential change per drop (ΔE / ΔV) was maximum was defined as equivalence point B.

[0198] The values ​​obtained as described above were used to calculate the amount of acidic functional groups (mmol / g) using the following formula (2). Formula (2): Acidic functional group amount (mmоl / g) =(BA)×0.05×(30 / 15) / S

[0199] In formula (2), A represents the titration volume (mL) of hydrochloric acid at equivalence point A. B represents the titration volume (mL) of hydrochloric acid at equivalence point B. S represents the mass (g) of the sample.

[0200] (vi) Amount of water-soluble base component and amount of water-soluble weak salt The amounts of water-soluble basic components and water-soluble weak salts were determined by the titration method described below. Specifically, 1 g of freeze-dried sample (component (C-1), component (C-2), or component (C-3)) was mixed with 30 mL of hydrochloric acid aqueous solution (0.05 mol / L), shaken up and down for 4 hours using a shaker, and then left to stand for a while.

[0201] Subsequently, the obtained supernatant was filtered using a syringe filter, and a 0.05 mol / L sodium hydroxide aqueous solution was added dropwise to 15 mL of the resulting filtrate. The points where the potential change per drop (ΔE / ΔV) was maximum were designated as equivalence point C1 and equivalence point C2, starting from the point with the largest drop.

[0202] Furthermore, as a blank test, 0.05 mol / L sodium hydroxide solution was added dropwise to 15 mL of hydrochloric acid solution (0.05 mol / L), and the point where the potential change per drop (ΔE / ΔV) was maximum was defined as the equivalence point D.

[0203] Then, the amount of water-soluble basic component (mmol / g) was calculated using the following formula (3). Formula (3): Amount of water-soluble base component (mmol / g) =(d-c1)×0.05×(30 / 15) / S

[0204] In formula (3), d represents the titration volume (mL) of the sodium hydroxide solution at the equivalence point D. c1 represents the titration volume (mL) of the sodium hydroxide aqueous solution at the equivalence point C1. S represents the mass (g) of the sample.

[0205] In the titration procedure described above, if only one equivalence point C appears, the amount of water-soluble weak salt is 0 mmol / g. If two equivalence points C (equivalence points C1 and C2) appear, the amount of water-soluble weak salt (mmol / g) was calculated using the following formula (4). Formula (4): Amount of water-soluble weak acid salt (mmol / g) =(c1-c2)×0.05×(30 / 15) / S

[0206] In formula (4), c1 represents the titration volume (mL) of the sodium hydroxide aqueous solution at the equivalence point C1. c2 represents the titration volume (mL) of the sodium hydroxide solution at the equivalence point C2 (where c1 > c2). S represents the mass (g) of the sample.

[0207] (vii) Total nitrogen content The total nitrogen was measured by chemiluminescence using a trace total nitrogen analyzer TN-2100H (product name, manufactured by Nitto Seikou Analytech Co., Ltd.) in accordance with the method specified in JIS K 2609.

[0208] <Example 1> (1) Production of propylene resin compositions For 61.5 parts by mass of component (A-1), 1.5 parts by mass of component (B-1), and 37 parts by mass of component (C-1), that is, for a total of 100 parts by mass of components (A), (B), and (C), Songnox 6260 (trade name, Songwon International) is added as an antioxidant. A mixture was obtained by adding and mixing 0.1 parts by weight of AG's bis-2,4-di-t-butylphenylpentaerythritol diphosphite, 0.2 parts by weight of Sumirizer GA-80 (trade name, manufactured by Sumitomo Chemical Co., Ltd., 3,9-bis[1,1-dimethyl-2-(β-(3-t-butyl-4-hydroxy-5-methylphenyl)propionyloxy)ethyl]-2,4,8,10-tetraoxaspiro[5,5]undecane), 0.2 parts by weight of Sumirizer TPM (trade name, manufactured by Sumitomo Chemical Co., Ltd., dimyristylthiodipropionate), 0.1 parts by weight of AL-PTBBA (hydroxy-di(p-tert-butylbenzoate)aluminum) as a nucleating agent, and 0.7 parts by weight of pigment MB containing acetylene black as a pigment.

[0209] Subsequently, the obtained mixture was melt-kneaded using a twin-screw compounding extruder at an extrusion rate of 50 kg / hr, 230°C, and a screw rotation speed of 200 rpm to produce a pelletized propylene-based resin composition. In the production of the propylene-based resin composition, component (C-1) was added separately by side-feeding from the side feeder of the twin-screw compounding extruder.

[0210] (2) Production of molded articles of propylene resin composition Using the obtained propylene resin composition pellets, injection molding was performed using an injection molding machine (M70, manufactured by Meiki Seisakusho Co., Ltd.) at a cylinder temperature of 230°C and a mold temperature of 50°C to obtain ISO multipurpose test specimens.

[0211] Furthermore, using the obtained propylene resin composition pellets, an ASTM Type 1 dumbbell with a weld formed in the center of the parallel section was obtained as a test specimen by injection molding using an injection molding machine (Toshiba Machine IS100EN) at a cylinder temperature of 240°C and a mold temperature of 50°C.

[0212] (3) Evaluation The physical properties of the obtained test specimens were evaluated as described above. The evaluation results are shown in Tables 2 and 3 below.

[0213] <Examples 2-7> A propylene-based resin composition and molded article were manufactured and evaluated in the same manner as in Example 1, except that components (A) to (D) were as shown in Tables 2 and 3 below. The results are shown in Tables 2 and 3 below.

[0214] <Comparative Examples 1-3> A propylene-based resin composition and molded article were manufactured and evaluated in the same manner as in Example 1, except that components (A) to (D) were as shown in Tables 2 and 3 below. The results are shown in Tables 2 and 3 below.

[0215] [Table 2]

[0216] [Table 3]

Claims

1. In a polypropylene resin composition comprising component (A) a polypropylene polymer, component (B) an acid-modified polypropylene polymer, and component (C) glass fibers, when the total amount of the polypropylene resin composition is 100% by mass, Component (A) Polypropylene polymer in an amount of 40 to 80% by mass, Component (B) Acid-modified polypropylene polymer in an amount of 0.1 to 10% by mass, Component (C) Glass fiber having a water-soluble base component content of 0.1 mmol / g or less and a water-soluble weak acid component content of 0.1 mmol / g or less, comprising 10 to 55% by mass. A polypropylene resin composition containing the following:

2. The polypropylene resin composition according to claim 1, wherein the component (C) is a glass fiber having a total nitrogen content of 70 ppm or more as measured by chemiluminescence.

3. The polypropylene resin composition according to claim 1 or 2, wherein the melt flow rate measured under conditions of a temperature of 230°C and a load of 2.16 kgf is 1 to 20 g / 10 min.

4. The polypropylene resin composition according to any one of claims 1 to 3, wherein component (B) is an acid-modified polypropylene polymer in which the total amount of grafts of unsaturated carboxylic acid units and unsaturated carboxylic acid derivative units is 0.3% by mass or more, and the melt flow rate measured at a temperature of 230°C and a load of 2.16 kgf is 300 g / 10 min or less.

5. The polypropylene resin composition according to any one of claims 1 to 4, wherein the total amount of component (A), component (B), and component (C) is 100 parts by mass, and further comprising 0.01 to 1 part by mass of component (D), a nucleating agent.

6. A molded article comprising the polypropylene resin composition according to any one of claims 1 to 5.

7. An air intake manifold comprising the polypropylene resin composition according to any one of claims 1 to 5.

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