Polypropylene-based resin composition

Abstract

To provide a material which can achieve both fire resistance and flame shielding properties that are durable against flame contact for a long time, and good flowability excellent in moldability.SOLUTION: A propylene-based resin composition contains a polypropylene-based resin (A) satisfying a requirement (A1), a flame retardant (B) satisfying a requirement (B1), and a fiber (C) satisfying a requirement (C1), and satisfies Condition 1 and Condition 2.

Description

[Technical Field]

[0001] The present invention relates to a polypropylene resin composition, and more particularly to a polypropylene resin composition containing a phosphorus-based flame retardant and glass fibers and having excellent fire resistance and flame barrier properties. [Background technology]

[0002] Taking advantage of their superior chemical and mechanical properties, polyolefin resins are widely used in a variety of fields, including building materials, automobile parts, packaging materials, and home appliances, and their applications are expanding. However, many polyolefin resins are flammable, and flame retardancy is required for some applications. A widely used flame retardant method has traditionally been a combination of a bromine-based flame retardant and antimony trioxide, a flame retardant promoter.

[0003] However, flame retardant methods using bromine-based flame retardants have poor shape retention when the material softens due to heat, making it difficult to withstand prolonged flame contact.In contrast, flame retardant methods using phosphorus-based flame retardants, especially those that form carbonaceous char after combustion, carbonize the flame-contact surface and retain their shape, making them fire-resistant and flame-blocking, and are expected to be able to withstand relatively long periods of flame contact.

[0004] On the other hand, in the case of materials using phosphorus-based flame retardants, as exemplified by Patent Documents 1 and 2, although many studies have been conducted on self-extinguishing properties such as oxygen index and UL94 V tests, there have been few examples of in-depth studies on fire resistance and flame retardancy, and there has been a long awaited demand for materials that clearly possess the fire resistance and flame retardancy that society demands.

[0005] In recent years, a study has been reported in Patent Document 3, in which the fire resistance of a test piece in which a phosphorus-based flame retardant and glass fiber are combined is studied.

[0006] However, the technology disclosed in Patent Document 3 does not have a sufficient flame exposure time. For example, China's GB / T 38031-2020 standard assumes the occurrence of an EV fire and requires that "after a battery cell ignites in the battery pack, no smoke or fire should be emitted outside the battery pack for five minutes." However, the invention in Patent Document 3 does not take into consideration fire resistance performance of more than five minutes, and does not discuss materials with the fire resistance and flame blocking properties that society actually requires. In other words, the problem of providing materials with the performance to withstand long-term flame exposure, which will be required in the future, remains. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Japanese Patent Application Laid-Open No. 2003-026935 [Patent Document 2] JP 2011-088970 A [Patent Document 3] International Publication No. 2020-071420 Brochure Summary of the Invention [Problem to be solved by the invention]

[0008] In view of the above problems, the object of the present invention is to provide a material that combines a phosphorus-based flame retardant, glass fiber, and polypropylene, and that has both fire resistance and flame barrier properties that can withstand long-term flame contact and good fluidity that is excellent in moldability. [Means for solving the problem]

[0009] As a result of extensive research conducted to solve the above-mentioned problems, the inventors have found that the above-mentioned problems can be solved by blending a flame retardant and fiber in a specific ratio with a polypropylene resin and optimizing the melt flow rate (hereinafter sometimes abbreviated as MFR) of the resin portion relative to the amount of flame retardant in the resulting polypropylene resin composition. Based on these findings, the present invention has been completed.

[0010] That is, the present invention has the following configuration. [1] A propylene-based resin composition comprising a polypropylene-based resin (A) that satisfies the following requirement (A1), a flame retardant (B) that satisfies the following requirement (B1), and a fiber (C) that satisfies the following requirement (C1), and characterized in that the composition satisfies the following conditions 1 and 2: Requirement (A1) The polypropylene resin (A) contains at least one propylene polymer selected from the group consisting of propylene homopolymers, propylene random copolymers, and propylene block copolymers. Requirement (B1) The flame retardant (B) is an organic flame retardant. Requirement (C1) The fiber (C) is a glass fiber. Condition 1 The propylene-based resin composition contains 24 to 65% by weight of a polypropylene-based resin (A), 5 to 26% by weight of a flame retardant (B), and 30 to 50% by weight of fibers (C) (wherein the total of the polypropylene-based resin (A), the flame retardant (B), and the fibers (C) is 100% by weight). Condition 2 The melt flow rate (MFR, 230°C, 2.16 kg load) of the polypropylene resin (A) and the content of the flame retardant (B) (where the total of the polypropylene resin (A), the flame retardant (B), and the fiber (C) is taken as 100% by weight) satisfy either (Condition 2-1) or (Condition 2-2) below. (Condition 2-1) The content of the flame retardant (B) (unit: weight %, where the total of the polypropylene-based resin (A), the flame retardant (B), and the fiber (C) is 100 weight %) is 5 weight % or more and less than 18 weight %, and the melt flow rate (MFR, 230°C, 2.16 kg load) of the polypropylene-based resin (A) is 75 g / 10 min or less. (Condition 2-2) The content of the flame retardant (B) (unit: weight %, where the total of the polypropylene-based resin (A), the flame retardant (B), and the fiber (C) is 100 weight %) is 18 weight % or more and 26 weight % or less, and the melt flow rate (MFR, 230°C, 2.16 kg load) of the polypropylene-based resin (A) is 105 g / 10 min or less. [2] The propylene-based resin composition according to [1], wherein the polypropylene-based resin (A) further satisfies the following requirement (A2): Requirements (A2) The polypropylene resin (A) contains at least two types of polypropylene resins (Aa) and (Ab), and the melt flow rate (MFR, 230°C, 2.16 kg load) of the polypropylene resin (Aa) is in the range of 60 to 2000 / 10 min. [3] The propylene-based resin composition according to [1] or [2], wherein the fibers (C) further satisfy the following requirement (C2): Requirement (C2) As the fiber (C), glass fiber having a fiber length of 1 to 20 mm is used. [4] The propylene-based resin composition according to any one of [1] to [3], wherein the flame retardant (B) is a phosphorus-based flame retardant. [5] The propylene-based resin composition according to [4], wherein the flame retardant (B) is a polyphosphate. [6] A molded article obtained from the propylene-based resin composition according to any one of [1] to [5]. [Effects of the Invention]

[0011] The present invention makes it possible to provide a material that has both fire resistance and flame barrier properties that can withstand long-term flame contact, and good flowability that allows for excellent moldability.

[0012] The present invention provides a propylene-based resin composition comprising a polypropylene-based resin (A) that satisfies the following requirement (A1), a flame retardant (B) that satisfies the following requirement (B1), and a fiber (C) that satisfies the following requirement (C1), and characterized by satisfying the following conditions 1 and 2: Requirement (A1) The polypropylene resin (A) contains at least one propylene polymer selected from the group consisting of propylene homopolymers, propylene random copolymers, and propylene block copolymers. Requirement (B1) The flame retardant (B) is an organic flame retardant. Requirement (C1) The fiber (C) is a glass fiber. Condition 1 The propylene-based resin composition contains 24 to 65% by weight of a polypropylene-based resin (A), 5 to 26% by weight of a flame retardant (B), and 30 to 50% by weight of fibers (C) (wherein the total of the polypropylene-based resin (A), the flame retardant (B), and the fibers (C) is 100% by weight). Condition 2 The melt flow rate (MFR, 230°C, 2.16 kg load) of the polypropylene resin (A) and the content of the flame retardant (B) (where the total of the polypropylene resin (A), the flame retardant (B), and the fiber (C) is taken as 100% by weight) satisfy either (Condition 2-1) or (Condition 2-2) below. (Condition 2-1) The content of the flame retardant (B) (unit: weight %, where the total of the polypropylene-based resin (A), the flame retardant (B), and the fiber (C) is 100 weight %) is 5 weight % or more and less than 18 weight %, and the melt flow rate (MFR, 230°C, 2.16 kg load) of the polypropylene-based resin (A) is 75 g / 10 min or less. (Condition 2-2) The content of the flame retardant (B) (unit: weight %, where the total of the polypropylene-based resin (A), the flame retardant (B), and the fiber (C) is 100 weight %) is 18 weight % or more and 26 weight % or less, and the melt flow rate (MFR, 230°C, 2.16 kg load) of the polypropylene-based resin (A) is 105 g / 10 min or less.

[0013] Each item of the propylene-based resin composition of the present invention will be described in detail below.

[0014] 1. Propylene-based resin composition The propylene-based resin composition of the present invention satisfies the following condition 1.

[0015] Condition 1 The propylene resin composition contains 24 to 65% by weight of a polypropylene resin (A), 5 to 26% by weight of a flame retardant (B), and 30 to 50% by weight of fibers (C) (wherein the total of the polypropylene resin (A), the flame retardant (B), and the fibers (C) is 100% by weight). Details of the polypropylene resin (A), the flame retardant (B), and the fibers (C) will be described later.

[0016] The propylene resin composition must contain 24 to 65% by weight of polypropylene resin (A), preferably 29 to 59% by weight, more preferably 34 to 54% by weight, and more preferably 40 to 49% by weight. The flame retardant (B) must be contained in an amount of 5 to 26% by weight, preferably 10 to 25% by weight, more preferably 14 to 24% by weight, and more preferably 18 to 23% by weight. The fiber (C) must be contained in an amount of 30 to 50% by weight, preferably 31 to 46% by weight, more preferably 32 to 42% by weight, and more preferably 33 to 38% by weight. By setting the contents of the polypropylene-based resin (A), the flame retardant (B), and the fiber (C) within these ranges, it is possible to provide a material that can achieve both fire resistance and flame barrier properties that can withstand long-term flame contact, and fluidity that allows excellent moldability.

[0017] The propylene-based resin composition of the present invention further satisfies the following condition 2.

[0018] Condition 2 The melt flow rate (MFR, 230°C, 2.16 kg load) of the polypropylene resin (A) and the content of the flame retardant (B) (where the total of the polypropylene resin (A), the flame retardant (B), and the fiber (C) is taken as 100% by weight) satisfy either (Condition 2-1) or (Condition 2-2) below. (Condition 2-1) The content of the flame retardant (B) (unit: weight %, where the total of the polypropylene-based resin (A), the flame retardant (B), and the fiber (C) is 100 weight %) is 5 weight % or more and less than 18 weight %, and the melt flow rate (MFR, 230°C, 2.16 kg load) of the polypropylene-based resin (A) is 75 g / 10 min or less. (Condition 2-2) The content of the flame retardant (B) (unit: weight %, where the total of the polypropylene-based resin (A), the flame retardant (B), and the fiber (C) is 100 weight %) is 18 weight % or more and 26 weight % or less, and the melt flow rate (MFR, 230°C, 2.16 kg load) of the polypropylene-based resin (A) is 105 g / 10 min or less.

[0019] Generally, polypropylene resins (A) with a lower melt flow rate tend to have better shape retention when softened by heat, such as exposure to flame, and have good fire resistance and flame barrier properties even when the content of flame retardant (B) is low. On the other hand, even when the melt flow rate of polypropylene resins (A) is high, if the content of flame retardant (B) is high, in addition to the flame retardant effect of flame retardant (B), the melt flow rate of the mixture of polypropylene resins (A) and flame retardant (B) will decrease, so by increasing the content of flame retardant (B), it is possible to improve shape retention and achieve good fire resistance and flame barrier properties. In the present invention, in the region where the content of the flame retardant (B) is low, i.e., the region where the content of the flame retardant (B) (unit: weight %, where the total of the polypropylene resin (A), the flame retardant (B), and the fiber (C) is 100 weight %) is 5 weight % or more and less than 18 weight %, as defined in (Condition 2-1), sufficient fire resistance and flame protection can be achieved by setting the melt flow rate of the polypropylene resin (A) to 75 g / 10 min or less. Here, if the melt flow rate of the polypropylene resin (A) exceeds 75 g / 10 min, sufficient shape retention may not be achieved, and it may be difficult to achieve sufficient fire resistance and flame protection. Within this range, the melt flow rate is preferably 74 g / 10 min or less, more preferably 73 g / 10 min or less, even more preferably 72 g / 10 min or less, particularly preferably 71 g / 10 min or less, and especially preferably 70 g / 10 min or less. Furthermore, in the region where the content of flame retardant (B) is high, i.e., the region where the content of flame retardant (B) (unit: weight %, where the total of polypropylene resin (A), flame retardant (B), and fiber (C) is 100 weight %) specified in (Condition 2-2) is 18 weight % or more and 26 weight % or less, good fire resistance and flame protection performance can be obtained even if the melt flow rate of polypropylene resin (A) exceeds 75 g / 10 min, as long as it is 105 g / 10 min or less. However, even in the region where the content of flame retardant (B) is high (Condition 2-2), if the melt flow rate of polypropylene resin (A) exceeds 105 g / 10 min, sufficient fire resistance and flame protection may not be achieved. Within this range, the melt flow rate is preferably 104 g / 10 min or less, more preferably 103 g / 10 min or less, even more preferably 102 g / 10 min or less, particularly preferably 101 g / 10 min or less, and especially preferably 100 g / 10 min or less. In both (Condition 2-1) and (Condition 2-2), the lower limit of the melt flow rate of the polypropylene resin (A) is usually 0.5 g / 10 min, preferably 0.8 g / 10 min, more preferably 1.0 g / 10 min, and even more preferably 1.5 g / 10 min. By setting the lower limit of the melt flow rate of the polypropylene resin (A) within this range, sufficient shape retention can be obtained, sufficient fire resistance and sufficient flame retardancy can be exhibited, and good moldability can be obtained. In other words, if the lower limit of the melt flow rate of the polypropylene resin (A) is lower than the above range, there is a high risk of deterioration in moldability.

[0020] (1) Polypropylene resin (A) The polypropylene resin (A) used in the present invention will be described in detail below.

[0021] Requirement (A1) The polypropylene resin (A) used in the present invention contains at least one propylene polymer selected from the group consisting of propylene homopolymers, propylene random copolymers, and propylene block copolymers. The propylene random copolymer is preferably a propylene-α-olefin random copolymer. Furthermore, the propylene block copolymer is preferably a propylene-α-olefin block copolymer. Hereinafter, in this specification, the propylene-α-olefin block copolymer and the propylene-α-olefin random copolymer may be simply referred to as "propylene-α-olefin copolymer." The propylene-α-olefin copolymer preferably used is a copolymer containing propylene and an α-olefin other than propylene having 2 to 8 carbon atoms as a comonomer, a random copolymer or block copolymer of propylene and an α-olefin having a propylene content of 70 to 99.99% by weight (i.e., a comonomer content of 0.01 to 30% by weight), more preferably a random copolymer or block copolymer of propylene and an α-olefin having a propylene content of 90% by weight or more. Also, it may be a mixture of random copolymers or block copolymers containing different α-olefins.

[0022] The comonomer, which is an α-olefin having 2 to 8 carbon atoms other than propylene and is copolymerized with propylene, may be used alone or in combination of two or more. Specific examples of the propylene-α-olefin copolymer include binary copolymers such as propylene-ethylene copolymer, propylene-butene-1 copolymer, propylene-pentene-1 copolymer, propylene-hexene-1 copolymer, and propylene-octene-1 copolymer, and ternary copolymers such as propylene-ethylene-butene-1 copolymer and propylene-ethylene-hexene-1 copolymer, with propylene-ethylene random copolymer and propylene-ethylene-butene-1 random copolymer being preferred. The content of the α-olefin monomer in the propylene-α-olefin copolymer is usually about 0.01 to 30% by weight, preferably 1 to 20% by weight, and more preferably about 1 to 10% by weight.

[0023] Examples of the α-olefins having 2 to 8 carbon atoms other than propylene include ethylene, 1-butene, 2-methyl-1-propene, 1-pentene, 2-methyl-1-butene, 3-methyl-1-butene, 1-hexene, 2-ethyl-1-butene, 2,3-dimethyl-1-butene, 2-methyl-1-pentene, 3-methyl-1-pentene, 4-methyl-1-pentene, 3,3-dimethyl-1-butene, 1-heptene, methyl-1-hexene, dimethyl-1-pentene, ethyl-1-pentene, trimethyl-1-butene, and 1-octene.

[0024] From the viewpoint of moldability, the polypropylene resin (A) preferably has a melting point of 100 to 170°C, more preferably 150 to 165°C. The melting point of the polypropylene resin can be appropriately controlled mainly by the types of propylene and α-olefins other than propylene used as raw materials, the copolymerization ratio, the melt flow rate (MFR), etc. The "melting point" referred to in this specification is the melting peak temperature measured by a differential scanning calorimeter (DSC).

[0025] The polypropylene resin (A) used in the present invention must satisfy either the above-mentioned (Condition 2-1) or (Condition 2-2) with respect to the melt flow rate (MFR) according to JIS K7210 [measurement temperature 230°C, load 2.16 kg (21.18 N)]. Therefore, the melt flow rate (MFR) is usually 0.5 to 105 g / 10 min, preferably 1.0 to 100 g / 10 min, more preferably 5.0 to 90 g / 10 min, and even more preferably 10 to 75 g / 10 min. By setting the melt flow rate (MFR) within this range, the propylene resin composition of the present invention and molded articles obtained by molding it can maintain good flame retardancy, i.e., fire resistance, flame blocking, and moldability, while also exhibiting good scratch resistance and flexural strength. That is, if the melt flow rate (MFR) is less than 0.5 g / 10 min, the load when molding the propylene-based resin composition of the present invention increases, resulting in poor moldability and the possibility of discoloration of the molded article and a poor appearance. Conversely, if the MFR exceeds 105 g / 10 min, scratch resistance and bending strength may be impaired, and sufficient shape retention may not be achieved, resulting in the possibility that sufficient fire resistance and flame barrier properties may not be achieved. When the polypropylene-based resin (A) contains two or more types of propylene polymers, all of these two or more types of propylene polymers may have a melt flow rate (MFR) within the above-mentioned range, or some or all of the two or more types of propylene polymers may have a melt flow rate (MFR) outside the above-mentioned range, but the polypropylene-based resin (A) as a whole may have a melt flow rate (MFR) within the above-mentioned range.

[0026] Furthermore, the polypropylene resin (A) preferably used in the present invention has an isotactic pentad fraction (mmmm fraction), which indicates the degree of crystallinity, of 96% or more, and more preferably an isotactic pentad fraction of 97% or more. An isotactic pentad fraction of 96% or more is preferred because it provides good scratch resistance and bending strength. This is due to the effect of the crystal orientation of the polypropylene resin (A) on the surface layer of the molded article. The degree of crystallinity of the polypropylene resin (A) can be adjusted by controlling the copolymerization ratio of the raw materials and the molecular weight distribution by using the catalyst used. The isotactic pentad fraction (mmmm) is 13 It is a value measured using C-NMR (nuclear magnetic resonance method), and is a nuclear magnetic resonance spectrum ( 13 The isotactic pentad fraction is the isotactic fraction of pentad units in a polypropylene molecular chain measured using C-NMR. That is, the isotactic pentad fraction is the fraction of propylene units in which five consecutive propylene monomer units are isotactically bonded. Specifically, 13 The isotactic pentad unit is measured by the intensity fraction of the mmmm peak among all absorption peaks in the methyl carbon region of the C-NMR spectrum, and for example, a 270 MHz FT-NMR device manufactured by JEOL Ltd. is used.

[0027] The catalyst used to obtain the polypropylene resin (A) used in the present invention is not particularly limited, and known catalysts can be used. For example, so-called Ziegler-Natta catalysts, which combine a titanium compound and an organoaluminum compound (e.g., as described in Polypropylene Handbook (first edition, first printing published May 15, 1998)), or metallocene catalysts (e.g., as described in JP-A-5-295022) can be used.

[0028] The polymerization process used to obtain the polypropylene resin (A) used in the present invention is not particularly limited, and any known polymerization process can be used. For example, a slurry polymerization method, a bulk polymerization method, a gas phase polymerization method, etc. can be used. Furthermore, either a batch polymerization method or a continuous polymerization method can be used, and if desired, a multi-stage continuous polymerization method such as a two-stage or three-stage method can also be used. Furthermore, the polypropylene resin (A) can also be produced by mechanically melt-kneading two or more types of propylene polymers. Various polypropylene resins that can be used as the polypropylene-based resin (A) are commercially available from many companies, such as the Novatec series manufactured by Japan Polypropylene Corp. It is also possible to purchase and use a product having the desired physical properties from these commercially available products.

[0029] The polypropylene resin (A) used in the present invention preferably further satisfies the following requirement (A2). Requirements (A2) The polypropylene resin (A) contains at least two types of polypropylene resins (Aa) and (Ab), and the melt flow rate (MFR, 230°C, 2.16 kg load) of the polypropylene resin (Aa) is in the range of 60 to 2000 / 10 min. In one embodiment of the present invention, a masterbatch is produced by kneading the flame retardant (B) and the fiber (C) into different polypropylene-based resins (carrier resins), and then, if necessary, kneading the masterbatch with another polypropylene resin in a molding machine. In this case, a low melt flow rate (MFR) of the carrier resin for the fiber masterbatch results in poor dispersion of the fiber (C), so a resin with a high MFR must be used as the carrier resin. On the other hand, in this invention, a polypropylene-based resin with a low MFR must be used to adjust the overall MFR of the polypropylene-based resin (A), because a too high MFR of the polypropylene-based resin (A) reduces fire resistance and flame retardancy. Therefore, in an embodiment using a masterbatch in which fiber (C) is kneaded into a polypropylene-based resin (carrier resin), at least two polypropylene-based resins are required. In this case, using the other polypropylene-based resin as the carrier resin in the masterbatch for the flame retardant (B) is preferable because it simplifies the kneading process. The melt flow rates (MFR) of the two or more polypropylene resins (Aa) may be the same or different, but it is preferable that the melt flow rate (MFR) of (Aa) is larger than the melt flow rate (MFR) of (Ab), since this makes it easier to adjust the melt flow rate (MFR) of the polypropylene resin (A) to fall within a desired range.

[0030] Here, the melt flow rate (MFR) of the polypropylene resin (Aa) is preferably 60 to 2000 g / 10 min, more preferably 70 to 1000 g / 10 min, even more preferably 80 to 900 g / 10 min, particularly preferably 100 to 800 g / 10 min, and most preferably 100 to 700 g / 10 min. The melt flow rate (MFR) of the polypropylene resin (A) as a whole, which contains at least two types of polypropylene resins (Aa) and (Ab), is the same as the melt flow rate (MFR) of the polypropylene resin (A) described above. In this specification, the melt flow rate (MFR) is a value measured in accordance with JIS K7210 at a test temperature of 230°C and a load of 2.16 kg. When a mixture of multiple polypropylene resins is used as the polypropylene resin (A), it is preferable to use the melt flow rate (MFR) value calculated by the logarithmic additivity rule (see, for example, the following formula (1)) described in Japanese Patent No. 6331720. A ) represents the melt flow rate of the resin obtained by calculation, hereafter referred to as MFR A It is sometimes abbreviated as: log(MFR A ) = {(% by weight of component (PP-A) × log (MFR of component (PP-A)) + (% by weight of component (PP-B) × log (MFR of component (PP-B)) + (% by weight of component (PP-C) × log (MFR of component (PP-C))} / 100 Formula (1)

[0031] The types of polypropylene resin (Aa) and polypropylene resin (Ab) (ie, types of propylene polymers), the preferred melting points, and the preferred isotactic pentad fractions are as described in detail for polypropylene resin (A). In addition, two or more types of polypropylene resins (Ab) may be contained.

[0032] The ratio of the total content of the polypropylene resins (Aa) to the total content of the polypropylene resins (Ab) in the polypropylene resin (A) can be set arbitrarily, taking into consideration the melt flow rate (MFR) of the entire polypropylene resin (A). That is, as described above, in the present invention, it is important to set the melt flow rate (MFR) of the polypropylene resin (A) within a desired range and, within that desired range, to adjust the content of the flame retardant (B) within a specific range.

[0033] (2) Flame retardant (B) The flame retardant (B) used in the present invention will be described in detail below.

[0034] Requirement (B1) The flame retardant (B) used in the present invention is an organic flame retardant. Generally, a larger amount of inorganic flame retardant is required to achieve the required flame retardancy, and the specific gravity increases when a high level of flame retardancy is desired. In contrast, organic flame retardants can achieve flame retardancy with a relatively low addition amount, making it possible to achieve high flame retardancy with a relatively low specific gravity. Therefore, in the present invention, it is necessary to use an organic flame retardant as the flame retardant (B).

[0035] The organic flame retardant used in the present invention is not particularly limited, and various organic flame retardants such as halogen-based, phosphorus-based, and nitrogen compounds such as guanidine-based can be used, but phosphorus-based flame retardants are preferred.

[0036] Any phosphorus-based flame retardant generally used for polyolefins can be used, including compounds modified with various substituents such as trimethyl phosphate, triethyl phosphate, tripropyl phosphate, tributyl phosphate, tripentyl phosphate, trihexyl phosphate, tricyclohexyl phosphate, trixyl phosphate, cresyl diphenyl phosphate, dicresyl phenyl phosphate, dimethyl ethyl phosphate, trixyl phosphate, methyl dibutyl phosphate, ethyl dipropyl phosphate, and hydroxyphenyl diphenyl phosphate, phosphate compounds, and compounds or mixtures of phosphazene derivatives containing phosphorus and nitrogen. These phosphorus-based flame retardants may be used alone or in combination of two or more.

[0037] In a preferred embodiment of the present invention, the phosphorus-based flame retardant is a polyphosphate. When a polyphosphate is used as an organic flame retardant, it forms an intumescent layer during a reaction during combustion, which is suitable for improving fire resistance and flame protection. Examples of polyphosphates include the phosphates described in [Patent Document 1] JP-A-2003-026935, paragraphs

[0015] to

[0021] .

[0038] In addition to the phosphorus-based flame retardant, other organic flame retardants that do not fall under the category of phosphorus-based flame retardants, such as halogen-based and nitrogen compounds, can also be used.

[0039] Preferred examples of halogen-based flame retardants include organic halogenated aromatic compounds such as halogenated diphenyl compounds, halogenated bisphenol compounds, halogenated bisphenol-bis(alkyl ether) compounds, and halogenated phthalimide compounds, and halogenated bisphenol-bis(alkyl ether) compounds are particularly preferred. Examples of the halogenated diphenyl compound include halogenated diphenyl ether compounds, halogenated diphenyl ketone compounds, and halogenated diphenyl alkane compounds, and among these, halogenated diphenyl alkane compounds such as decabromodiphenylethane are preferred.

[0040] Examples of the halogenated bisphenol compounds include halogenated bisphenylalkanes, halogenated bisphenyl ethers, halogenated bisphenyl thioethers, and halogenated bisphenyl sulfones. Among these, halogenated bisphenyl thioethers such as bis(3,5-dibromo-4-hydroxyphenyl) sulfone are preferred.

[0041] Examples of the halogenated bisphenol bis(alkyl ether) compounds include (3,5-dibromo-4-2,3-dibromopropoxyphenyl)-(3-bromo-4-2,3-dibromopropoxyphenyl)methane, 1-(3,5-dibromo-4-2,3-dibromopropoxyphenyl)-2-(3-bromo-4-2,3-dibromopropoxyphenyl)ethane, 1-(3,5-dibromo-4-2,3-dibromopropoxyphenyl)-3-(3-bromo-4-2,3-dibromopropoxyphenyl)propane, 2,2-bis(3,5- Dibromo-4-2,3-dibromopropoxyphenyl)propane, (3,5-dichloro-4-2,3-dibromopropoxyphenyl)-(3-chloro-4-2,3-dibromopropoxyphenyl)methane, 1-(3,5-dichloro-4-2,3-dibromopropoxyphenyl)-2-(3-chloro-4-2,3-dibromopropoxyphenyl)ethane, 1-(3,5-dichloro-4-2,3-dibromopropoxyphenyl)-3-(3-chloro-4-2,3-dibromopropoxyphenyl)propane, bis(3,5-dibromo-4-2,3-dibromopropoxyphenyl) 1,2-bis(3,5-dibromo-4-2,3-dibromopropoxyphenyl)methane, 1,2-bis(3,5-dibromo-4-2,3-dibromopropoxyphenyl)ethane, 1,3-bis(3,5-dibromo-4-2,3-dibromopropoxyphenyl)propane, bis(3,5-dichloro-4-2,3-dibromopropoxyphenyl)methane, 1,2-bis(3,5-dichloro-4-2,3-dibromopropoxyphenyl)ethane, 1,3-bis(3,5-dichloro-4-2,3-dibromopropoxyphenyl)propane, 2-bis(3,5-dichloro-4-2,3-dibromopropoxyphenyl) nyl)propane, (3,5-dibromo-4-2,3-dibromopropoxyphenyl)-(3-bromo-4-2,3-dibromopropoxyphenyl) ketone, (3,5-dichloro-4-2,3-dibromopropoxyphenyl)-(3-chloro-4-2,3-dibromopropoxyphenyl) ketone, bis(3,5-dibromo-4-2,3-dibromopropoxyphenyl) ketone, bis(3,5-dichloro-4-2,3-dibromopropoxyphenyl) ketone, (3,5-dibromo-4-2,3-dibromopropoxyphenyl)-(3-bromo-4-2,3-dibromopropoxyphenyl) ether, (3,5-dichloro-4-2,3-dibromopropoxyphenyl)-(3-chloro-4-2,3-dibromopropoxyphenyl) ether, bis(3,5-dibromo-4-2,3-dibromopropoxyphenyl) ether, bis(3,5-dichloro-4-2,3-dibromopropoxyphenyl) ether, (3,5-dibromo-4-2,3-dibromopropoxyphenyl) bis(3,5-dibromo-4-2,3-dibromopropoxyphenyl)-(3-bromo-4-2,3-dibromopropoxyphenyl)thioether, (3,5-dichloro-4-2,3-dibromopropoxyphenyl)-(3-chloro-4-2,3-dibromopropoxyphenyl)thioether, bis(3,5-dibromo-4-2,3-dibromopropoxyphenyl)thioether, bis(3,5-dichloro-4-2,3-dibromopropoxyphenyl)thioether ether, (3,5-dibromo-4-2,3-dibromopropoxyphenyl)-(3-bromo-4-2,3-dibromopropoxyphenyl)sulfone, (3,5-dichloro-4-2,3-dibromopropoxyphenyl)-(3-chloro-4-2,3-dibromopropoxyphenyl)sulfone, bis(3,5-dibromo-4-2,3-dibromopropoxyphenyl)sulfone, bis(3,5-dichloro-4-2,3-dibromopropoxyphenyl)sulfone, among which brominated bisphenol A (brominated aliphatic ether), brominated bisphenol S (brominated aliphatic ether), chlorinated bisphenol A (chlorinated aliphatic ether), chlorinated bisphenol S (chlorinated aliphatic ether), especially etherified tetrabromobisphenol A and etherified tetrabromobisphenol S are preferred.

[0042] Examples of etherified tetrabromobisphenol A include tetrabromobisphenol A-bis(2,3-dibromopropyl ether) and 2,2-bis(3,5-dibromo-4-2,3-dibromopropoxyphenyl)propane. Examples of etherified tetrabromobisphenol S include bis(3,5-dibromo-4-2,3-dibromopropoxyphenyl)sulfone. Among these halogen-based flame retardants, bromine-based flame retardants are preferred because they have a high flame retarding effect and are less likely to decompose even when subjected to heat history during the production and molding of the polypropylene-based resin composition of the present invention.

[0043] Examples of the nitrogen compounds include melamine, piperazine, N,N,N',N'-tetramethyldiaminomethane, ethylenediamine, N,N'-dimethylethylenediamine, N,N'-diethylethylenediamine, N,N-dimethylethylenediamine, N,N-diethylethylenediamine, N,N,N',N'-tetramethylethylenediamine, N,N,N',N'-diethylethylenediamine, 1,2-propanediamine, and 1,3-propanediamine. , tetramethylenediamine, pentamethylenediamine, hexamethylenediamine, 1,7-diaminoheptane, 1,8-diaminooctane, 1,9-diaminononane, 1,10-diaminodecane, trans-2,5-dimethylpiperazine, 1,4-bis(2-aminoethyl)piperazine, 1,4-bis(3-aminopropyl)piperazine, acetoguanamine, benzoguanamine, acrylguanamine, 2,4-diamino-6-nonyl-1,3,5-trimethylguanamine Azine, 2,4-diamino-6-hydroxy-1,3,5-triazine, 2-amino-4,6-dihydroxy-1,3,5-triazine, 2,4-diamino-6-methoxy-1,3,5-triazine, 2,4-diamino-6-ethoxy-1,3,5-triazine, 2,4-diamino-6-propoxy-1,3,5-triazine, 2,4-diamino-6-isopropoxy-1,3,5-triazine, 2,4-diamino-6-mercapto-1,3,5-triazine Examples include compounds in which methyltriazine, 2-amino-4,6-dimercapto-1,3,5-triazine, ammeline, benzguanamine, acetoguanamine, phthalodiguanamine, melamine cyanurate, melamine pyrophosphate, butylenediguanamine, norbornenediguanamine, methylenediguanamine, ethylenedimelamine, trimethylenedimelamine, tetramethylenedimelamine, hexamethylenedimelamine, and 1,3-hexylenedimelamine are substituted. Commercially available products include ADEKA Corporation's ADK STAB FP2000, FP2100, FP2200, and FP2500S, as well as ammonium polyphosphate.

[0044] When a phosphorus-based flame retardant is used in combination with various organic flame retardants such as halogen-based and nitrogen-based compounds, the organic flame retardants may be used alone or in combination of two or more. For example, a phosphorus-based flame retardant may be used in combination with an organic halogen-based flame retardant and a nitrogen-based compound.

[0045] (3) Fiber (C) The fibers (C) used in the present invention will be described in detail below.

[0046] Requirement (C1) The fiber (C) is a glass fiber. The fibers (C) not only improve the physical properties such as rigidity and impact strength of the propylene-based resin composition of the present invention and the molded article obtained therefrom, but also contribute to the improvement of additional physical properties such as heat resistance, dimensional stability (e.g., reduction in the linear expansion coefficient), low shrinkage, and scratch resistance.

[0047] (3-1) Types of glass fibers and manufacturing methods The fiber (C) is a glass fiber as described above. The use of glass fiber as the fiber (C) is preferred from the standpoint of ease and economy in producing the propylene-based resin composition of the present invention and the molded article obtained therefrom. In order to further improve the effects of the present invention, two or more types of the fiber (C) may be used in combination, or the fiber (C) may be used in the form of a so-called masterbatch in which the fiber (C) is previously incorporated into the polypropylene-based resin (A) or the like at a relatively high concentration. In addition, materials that do not fall under the category of fiber (C), such as glass beads, glass balloons, mica, and various inorganic or organic fillers that do not fall under the category of fiber (C), can also be used in combination within a range that does not significantly impair the effects of the present invention.

[0048] The glass fiber can be used without any particular limitation, and examples of the type of glass used for the fiber include E glass, C glass, A glass, and S glass, with E glass being preferred among them. The method for producing the glass fiber is not particularly limited, and the glass fiber can be produced by various known production methods.

[0049] The fiber diameter of the glass fiber is preferably 3 μm to 25 μm, and more preferably 6 μm to 20 μm. By setting the fiber diameter of the glass fiber within this range, the glass fiber is less likely to break during the production and molding of the propylene-based resin composition of the present invention and the molded article obtained therefrom, and the aspect ratio of the fiber can be set within a favorable range, making it possible to effectively improve the rigidity and impact strength of the propylene-based resin composition of the present invention and the molded article obtained therefrom. That is, if the fiber diameter is less than 3 μm, the glass fiber may be more likely to break during the production and molding of the propylene-based resin composition of the present invention and the molded article obtained therefrom. On the other hand, if the fiber diameter exceeds 25 μm, the aspect ratio of the fiber decreases, and the effect of improving the rigidity and impact strength of the propylene-based resin composition of the present invention and the molded article obtained therefrom may be reduced.

[0050] Furthermore, it is preferable that the glass fiber as the fiber (C) further satisfies the following requirement (C2). Requirement (C2) As the fiber (C), glass fiber having a fiber length of 1 to 20 mm is used. This fiber length is determined from values ​​measured using a microscope, calipers, etc. Furthermore, when glass fiber-containing pellets are obtained using a method such as the so-called pultrusion method, the glass fiber length in the pellets is substantially the same as the length of one side of the pellets (in the extrusion direction), resulting in "glass fiber-containing pellets," and the length of the pellets may be used as the glass fiber length. Furthermore, the fiber diameter is determined from values ​​measured using a microscope, calipers, etc.

[0051] The glass fiber can also be used in the form of so-called chopped strand glass fiber, which is obtained by cutting the fiber yarn to a desired length. When using so-called chopped strand glass fibers as the glass fibers, shorter glass fiber lengths facilitate easier handling and kneading, and are therefore preferably 2 mm to 15 mm, more preferably 3 mm to 10 mm, and even more preferably 4 mm to 8 mm. By controlling the length of the glass fibers within this range, the propylene-based resin composition of the present invention and the molded articles obtained therefrom can have good physical properties such as rigidity and impact strength, as well as good moldability (fluidity). Specifically, if fiber (C) is glass fiber and its fiber length is less than 1 mm, the propylene-based resin composition of the present invention and the molded articles obtained therefrom may have poor physical properties such as rigidity and impact strength. On the other hand, if it exceeds 20 mm, the moldability (fluidity) may be poor. In this case, the fiber length can also be expressed as the length when the glass fiber is used as a raw material as is. However, this does not apply to glass fiber-containing pellets, which are formed by aggregating and integrating a large number of continuous glass fibers by melt extrusion, as described below; roving-like fibers are usually used. Two or more types of glass fibers can also be used in combination.

[0052] The glass fibers may be either surface-treated or untreated. However, in order to improve dispersibility in the polypropylene resin (A), it is preferable to use glass fibers that have been surface-treated with an organic silane coupling agent, a titanate coupling agent, an aluminate coupling agent, a zirconate coupling agent, a silicone compound, a higher fatty acid, a fatty acid metal salt, a fatty acid ester, or the like. Examples of organic silane coupling agents used in surface treatment include vinyltrimethoxysilane, γ-chloropropyltrimethoxysilane, γ-methacryloxypropyltrimethoxysilane, γ-aminopropyltrimethoxysilane, and 3-acryloxypropyltrimethoxysilane. Examples of titanate coupling agents include isopropyl triisostearoyl titanate, isopropyl tris(dioctylpyrophosphate)titanate, and isopropyl tri(N-aminoethyl)titanate. Examples of aluminate coupling agents include acetoalkoxyaluminum diisopropylate. Examples of zirconate coupling agents include tetra(2,2-diallyloxymethyl)butyl, di(tridecyl)phosphitozirconate, neopentyl(diallyl)oxy, and trineodecanoyl zirconate. Examples of silicone compounds include silicone oils and silicone resins.

[0053] Furthermore, examples of higher fatty acids used in surface treatment include oleic acid, capric acid, lauric acid, palmitic acid, stearic acid, montanic acid, caraic acid, linoleic acid, rosin acid, linolenic acid, undecanoic acid, and undecenoic acid. Examples of higher fatty acid metal salts include sodium salts, lithium salts, calcium salts, magnesium salts, zinc salts, and aluminum salts of fatty acids having 9 or more carbon atoms, such as stearic acid and montanic acid. Among these, calcium stearate, aluminum stearate, calcium montanate, and sodium montanate are preferred. Examples of fatty acid esters include polyhydric alcohol fatty acid esters such as glycerin fatty acid esters, alpha sulfone 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 the glass fibers.

[0054] The glass fibers may be subjected to a bundling (surface) treatment with a sizing agent. Examples of the sizing agent include epoxy-based sizing agents, aromatic urethane-based sizing agents, aliphatic urethane-based sizing agents, acrylic-based sizing agents, and maleic anhydride-modified polyolefin-based sizing agents. These sizing agents must be melted during melt-kneading with the polypropylene resin (A), and therefore, they preferably melt at 200° C. or less.

[0055] A specific example of the so-called chopped strand glass fiber is T480H manufactured by Nippon Electric Glass Co., Ltd.

[0056] These glass fibers may also be used as "glass fiber-containing pellets" prepared by melt-extruding a given amount of, for example, polypropylene resin (A) using a method such as the so-called pultrusion process to form pellets in which a large number of continuous glass fibers are aggregated and integrated, and the length of the glass fibers in the pellets is substantially the same as the length of one side of the pellets (in the extrusion direction), which is preferred from the viewpoint of further improving the physical properties, such as rigidity and impact strength, of the propylene resin composition of the present invention and molded articles obtained therefrom. In this case, "substantially" specifically means that 50% or more, preferably 90% or more of the glass fibers in the glass fiber-containing pellets have the same length (in the extrusion direction) as the length of the glass fiber-containing pellets, based on the total number of the glass fibers, and that the fibers are hardly broken during the preparation of the pellets.

[0057] The method for producing such glass fiber-containing pellets is not particularly limited, but for example, a method (pultrusion method, pultrusion method) in which a resin extruder is used to pull a large number of continuous glass fibers from a fiber rack through a crosshead die, and an arbitrary amount of polypropylene resin is melt-extruded (impregnated) in a molten state to aggregate and integrate the large number of glass fibers is preferred because it causes almost no fiber breakage.

[0058] The length (in the extrusion direction) of the glass fiber-containing pellets varies depending on the glass fiber used, but is, as mentioned above, 1 mm to 20 mm. When glass fiber-containing pellets are used as the glass fiber, a longer glass fiber length (length of the glass fiber-containing pellets) facilitates pellet production and handling, and is therefore preferably 3 mm to 18 mm, more preferably 4 mm to 15 mm, and particularly preferably 5 mm to 12 mm. By setting the length of the glass fiber, i.e., the length of the glass fiber-containing pellets, within this range, the propylene-based resin composition of the present invention and the molded articles obtained therefrom can have good physical properties such as rigidity and impact strength, as well as moldability (fluidity). That is, if the length is less than 1 mm, the propylene-based resin composition of the present invention and the molded articles obtained therefrom may have poor physical properties such as rigidity and impact strength, while if the length exceeds 20 mm, the moldability (fluidity), etc. may be poor. The fiber diameter of the glass fiber is usually 3 to 25 μm, preferably 5 to 23 μm, further preferably 7 to 21 μm, and even more preferably 9 to 19 μm. By setting the fiber diameter of the glass fiber within this range, dispersion of the glass fiber in the polypropylene-based resin is improved, and it becomes possible to maintain the flowability and mechanical properties of the resulting polypropylene-based resin composition within good ranges while simultaneously exhibiting good flame retardancy. The glass fiber content in the glass fiber-containing pellets is preferably 20% by weight to 70% by weight, based on 100% by weight of the entire pellets. When glass fiber-containing pellets having a glass fiber content in this range are used in the present invention, the propylene-based resin composition of the present invention and the molded article obtained therefrom can have good physical properties such as rigidity and impact strength, as well as moldability (fluidity). That is, when glass fiber-containing pellets having a glass fiber content of less than 20% by weight are used in the present invention, the propylene-based resin composition of the present invention and the molded article obtained therefrom may have poor physical properties such as rigidity and impact strength, while when glass fiber-containing pellets having a glass fiber content of 70% by weight or more are used, moldability (fluidity) may be poor.

[0059] (4) Additives (D) In addition to the polypropylene resin (A), the flame retardant (B), and the fiber (C), the propylene resin composition of the present invention may contain, as needed, an optional additive (D) that is usually used in polypropylene resins, within a range that does not impair the object of the present invention. Examples of additives (D) include nucleating agents, molecular weight regulators, foaming agents, pigments, ultraviolet absorbers, antioxidants, antistatic agents, neutralizing agents, metal deactivators, stabilizers, antibacterial agents, inorganic fillers, and rubber-like components.

[0060] As the molecular weight lowering agent, for example, various organic peroxides and so-called decomposition (oxidation) accelerators can be used, with organic peroxides being preferred. Specific examples of organic peroxides include benzoyl peroxide, t-butyl perbenzoate, t-butyl peracetate, t-butylperoxyisopropyl carbonate, 2,5-dimethyl-2,5-di(benzoylperoxy)hexane, 2,5-dimethyl-2,5-di(benzoylperoxy)hexyne-3, t-butyl-diperadipate, t-butylperoxy-3,5,5-trimethylhexanoate, methyl-ethyl ketone peroxide, cyclohexanone peroxide, di-t-butyl peroxide, dicumyl peroxide, 2,5-dimethyl-2,5-di(t-butylperoxy)hexane, 2,5-dimethyl-2,5-di(t-butylperoxy)hexyne-3, 1,3-bis-(t-butylperoxyisopropyl)benzene, t-butyl cumyl peroxide, 1,1-bis- Examples of the peroxyl groups include, but are not limited to, one or more peroxyl groups selected from the group consisting of (t-butylperoxy)-3,3,5-trimethylcyclohexane, 1,1-bis-(t-butylperoxy)cyclohexane, 2,2-bis-t-butylperoxybutane, p-menthane hydroperoxide, diisopropylbenzene hydroperoxide, cumene hydroperoxide, t-butyl hydroperoxide, p-cymene hydroperoxide, 1,1,3,3-tetramethylbutyl hydroperoxide, and 2,5-dimethyl-2,5-di(hydroperoxy)hexane.

[0061] The type of blowing agent that can be used in the present invention is not particularly limited, and known blowing agents used in plastics, rubber, etc. can be used. Also, any blowing agent used in various foam molding processes can be used, including physical blowing agents, decomposable blowing agents (chemical blowing agents), and microcapsules containing a thermal expansion agent. Specific examples of physical blowing agents include aliphatic hydrocarbons such as propane, butane, pentane, and hexane; alicyclic hydrocarbons such as cyclopentane and cyclohexane; halogenated hydrocarbons such as chlorodifluoromethane, difluoromethane, trifluoromethane, trichlorofluoromethane, dichlorodifluoromethane, chloromethane, dichloromethane, chloroethane, dichlorotrifluoroethane, dichlorofluoroethane, chlorodifluoroethane, dichloropentafluoroethane, tetrafluoroethane, difluoroethane, pentafluoroethane, trifluoroethane, trichlorotrifluoroethane, dichlorotetrafluoroethane, chloropentafluoroethane, and perfluorocyclobutane; and inorganic gases such as water, carbon dioxide, and nitrogen. These compounds may be used alone or in combination. Among these, aliphatic hydrocarbons such as propane, butane, and pentane, and carbon dioxide gas are preferred because they are inexpensive and have high solubility in polypropylene-based resins. In particular, when carbon dioxide gas is used, it is more preferred to use it under supercritical conditions of 7.4 MPa or higher and 31°C or higher, because this results in excellent diffusion and solubility in the propylene-based resin composition.

[0062] When using a physical foaming agent, a foam regulator can be used as needed. Examples of foam regulators include inorganic decomposable foaming agents such as ammonium carbonate, sodium bicarbonate (sodium bicarbonate), ammonium bicarbonate, and ammonium nitrite; azo compounds such as azodicarbonamide, azobisisobutyronitrile, and diazoaminobenzene; nitroso compounds such as N,N'-dinitrosopentanmethylenetetramine and N,N'-dimethyl-N,N'-dinitrosoterephthalamide; organic decomposable foaming agents such as benzenesulfonyl hydrazide, p-toluenesulfonyl hydrazide, p,p'-oxybisbenzenesulfonylsemicarbazide, p-toluenesulfonylsemicarbazide, trihydrazinotriazine, and barium azodicarboxylate; inorganic powders (inorganic powders) such as talc and silica; acid salts of polycarboxylic acids; and reaction mixtures of polycarboxylic acids with sodium carbonate or sodium bicarbonate. These foam regulators can be used alone or in combination. When a cell regulator is used, the blending amount of the cell regulator is preferably in the range of 0.01 to 5 parts by weight in pure form relative to 100 parts by weight of the propylene-based resin composition. Specific examples of decomposable blowing agents (chemical blowing agents) include mixtures of organic acids such as sodium bicarbonate and citric acid, azo-based blowing agents such as azodicarbonamide and barium azodicarboxylate, nitroso-based blowing agents such as N,N'-dinitrosopentamethylenetetramine and N,N'-dimethyl-N,N'-dinitrosoterephthalamide, sulfohydrazide-based blowing agents such as p,p'-oxybisbenzenesulfonylhydrazide and p-toluenesulfonylsemicarbazide, and trihydrazinotriazine. The amount of the foaming agent to be added is preferably in the range of 0.05 to 6.0 parts by weight, more preferably 0.05 to 3.0 parts by weight, even more preferably 0.5 to 2.5 parts by weight, and particularly preferably 1.0 to 2.0 parts by weight, relative to 100 parts by weight of the propylene-based resin composition.

[0063] The pigment may be any of known organic or inorganic pigments, including organic pigments such as azo, anthraquinone, phthalocyanine, quinacridone, isoindolinone, diosadin, perinone, quinophthalone, and perylene pigments, and inorganic pigments such as ultramarine, titanium oxide, titanium yellow, iron oxide (red oxide), chromium oxide, zinc white, and carbon black.

[0064] Examples of light stabilizers and ultraviolet absorbers include hindered amine compounds, benzotriazoles, benzophenones, and salicylates, which are effective in imparting and improving the weather resistance and durability of the propylene-based resin composition of the present invention and the molded articles produced therefrom. Specific examples of hindered amine compounds include condensates of dimethyl succinate and 1-(2-hydroxyethyl)-4-hydroxy-2,2,6,6-tetramethylpiperidine; poly[[6-(1,1,3,3-tetramethylbutyl)imino-1,3,5-triazine-2,4-diyl][(2,2,6,6-tetramethyl-4-piperidyl)imino]hexamethylene[(2,2,6,6-tetramethyl-4-piperidyl)imino]]; tetrakis(2,2,6,6-tetramethyl-4-piperidyl)1,2,3,4-butanetetracarboxylate; Examples of the benzotriazoles include 2-(2'-hydroxy-3',5'-di-t-butylphenyl)-5-chlorobenzotriazole and 2-(2'-hydroxy-3'-t-butyl-5'-methylphenyl)-5-chlorobenzotriazole. Examples of the benzophenones include 2-hydroxy-4-methoxybenzophenone and 2-hydroxy-4-n-octoxybenzophenone. Examples of the salicylate compounds include 4-t-butylphenyl salicylate and 2,4-di-t-butylphenyl 3',5'-di-t-butyl-4'-hydroxybenzoate. Here, the method of using the light stabilizer and the ultraviolet absorber in combination is preferable because it has a significant effect of improving weather resistance, durability, etc. Two or more of these may be used in combination.

[0065] As the antioxidant, for example, phenol-based, phosphorus-based, or sulfur-based antioxidants are effective in imparting or improving the heat resistance, processing stability, heat aging resistance, etc. of the polypropylene resin composition of the present invention and the molded articles obtained by molding it.

[0066] As the antistatic agent, for example, a nonionic or ionic antistatic agent is effective in imparting or improving the antistatic properties of the propylene-based resin composition of the present invention and the molded article obtained by molding it.

[0067] In particular, as the antistatic agent, ionic agents such as cationic, anionic, nonionic and amphoteric agents, and fatty acid partial esters such as glycerin fatty acid monoesters can be used. Specifically, alkyltrimethylammonium salts, dialkyldimethylammonium salts, benzalkonium salts, N,N-bis(2-hydroxyethyl)-N-(3-dodecyloxy-2-hydroxypropyl)methylammonium methosulfate, (3-laurylamidopropyl)trimethylammonium methylsulfate, stearamidopropyldimethyl-2-hydroxyethylammonium nitrate, stearamidopropyldimethyl-2-hydroxyethylammonium phosphate, cationic polymers, alkyl sulfonates, alkylbenzene sulfonates, sodium alkyl diphenyl ether disulfonate, alkyl nitrate ester salts, phosphorus Acid alkyl ester salts, alkyl phosphate amine salts, stearic acid monoglyceride, pentaerythritol fatty acid esters, sorbitan monopalmitate, sorbitan monostearate, diglycerin fatty acid esters, alkyldiethanolamines, alkyldiethanolamine fatty acid monoesters, alkyldiethanolamides, polyoxyethylene dodecyl ethers, polyoxyethylene alkylphenyl ethers, polyethylene glycol monolaurate, polyoxyethylene alkylamines, polyoxyethylene alkylamides, polyether block copolymers, cetyl betaine, hydroxyethyl imidazoline sulfate, etc. These may be used in combination of two or more.

[0068] Examples of nucleating agents that can be used include aromatic aluminum salt-based nucleating agents, aromatic sodium salt-based nucleating agents, phosphorus-based nucleating agents such as aromatic metal phosphate-based nucleating agents, sorbitol-based nucleating agents, rosin-based nucleating agents, petroleum resins, and talc. Examples of sorbitols, such as alkyl-substituted benzylidene sorbitol, include 1,3,2,4-dibenzylidene sorbitol, 1,3,2,4-di-(p-methylbenzylidene) sorbitol, 1,3-o-methylbenzylidene 2,4-p-methylbenzylidene sorbitol, 1,3,2,4-di-(p-ethylbenzylidene) sorbitol, and 1,3,2,4-di-(2',4'-dimethylbenzylidene) sorbitol. Phosphorus-based sorbitols include sodium bis(4-t-butylphenyl) phosphate, sodium 2,2'-ethylidene-bis(4,6-di-t-butylphenyl) phosphate, and organic phosphate complexes. Other sorbitols include sodium benzoate, aluminum pt-butylbenzoate, sodium montanate, calcium montanate, aluminum oxide, kaolin clay, talc, rosins, and petroleum resins. These may be used in combination of two or more.

[0069] As the metal deactivator, triazines, phosphones, epoxies, triazoles, hydrazides, oxamides, etc. can be used. Specific examples include N,N'-bis[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionyl]hydrazine, isophthalic acid bis(2-phenoxypropionylhydrazide), decanedicarboxylic acid disalicyloyl hydrazide, oxalic acid bisbenzylidenehydrazide, N,N'-bis{2-[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionyloxyl]ethyl}oxamide, 3-(N-salicyloyl)amino-1,2,4-triazole, acid amides, melamine, tris[2-t-butyl-4-thio(2'-methyl-4'-hydroxy-5-t-butyl)phenyl-5-methyl]phosphite, etc. These may be used in combination of two or more.

[0070] As a neutralizing agent, various fatty acid metal salts can be used. Specific examples include saturated or unsaturated fatty acids with a molecular weight of about 26 to 300, such as oleic acid (unsaturated C18), stearic acid (C18), palmitic acid (C18), myristic acid (C14), lauric acid (C12), erucic acid (unsaturated C22), and behenic acid (C22), and salts of metals such as lithium, sodium, calcium, magnesium, aluminum, and zinc. Two or more of these may be used in combination.

[0071] The antibacterial agent may be either an organic or inorganic antibacterial agent. Examples of organic antibacterial agents include chlorine-based, phenol-based, imidazole-based, or thiazole-based compounds, and quaternary ammonium compounds. Examples of inorganic antibacterial agents include zeolite-based, apatite-based, silica alumina-based, ceramic-based, zirconium phosphate-based, silica gel-based, hydroxyapatite-based, or calcium silicate-based antibacterial agents containing metals such as silver and zinc.

[0072] Furthermore, specific examples of inorganic fillers include talc, barium sulfate, clay, silica, calcium carbonate, magnesium carbonate, aluminum hydroxide, magnesium hydroxide, glass fiber, whiskers, and the like.

[0073] The rubber component may be a so-called elastomer or plastomer, such as ethylene-propylene rubber, ethylene-butene-1 rubber, ethylene-hexene rubber, ethylene-octene rubber, or styrene-butadiene rubber. Any commercially available rubber may be used as long as it does not impair the effects of the present invention.

[0074] 2. Method for preparing propylene-based resin composition Examples of methods for preparing the propylene-based resin composition of the present invention include a method in which a predetermined amount of flame retardant (B), fiber (C), and optional additive (D) are added directly to powder or pellets of polypropylene-based resin (A); a method in which a masterbatch containing powder of polypropylene-based resin (A), flame retardant (B), fiber (C), and optional additive (D) is prepared in advance and added to pellets of polypropylene-based resin; and a method in which flame retardant (B) and optional additive (D) are added to powder or pellets of polypropylene-based resin (A) to first prepare a masterbatch of flame retardant (B), and further fiber (C) and optional additive (D) are added to powder or pellets of polypropylene-based resin (A) to prepare a masterbatch of fiber (C), and then the obtained masterbatch of flame retardant (B) and the masterbatch of fiber (C) are melt-kneaded.

[0075] The polypropylene resin composition of the present invention can be obtained by any of the above methods. When these methods are used, known methods such as a tumbler mixer, a super mixer, a Henschel mixer, a screw blender, a ribbon blender, etc. Melt kneading is not particularly limited as long as it is a method in which melt kneading is carried out at a temperature equal to or higher than the melting point of the polypropylene resin (A) using, for example, a melt extruder, a Banbury mixer, etc.

[0076] The propylene-based resin composition of the present invention has an overall melt flow rate (MFR, 230°C, 2.16 kg load) of usually 1 to 60 g / 10 min, preferably 2 to 50 g / 10 min, more preferably 5 to 40 g / 10 min, and particularly preferably 10 to 30 g / 10 min. By setting the overall MFR within this range, good moldability can be maintained while at the same time good flame retardancy can be obtained.

[0077] 3. Molding and applications of propylene-based resin compositions (1) Molding Another aspect of the present invention is a molded article obtained from the propylene-based resin composition of the present invention. The propylene-based resin composition of the present invention can be molded by injection molding (including gas injection molding) or injection compression molding (including press injection, hot flow stamping molding, and gas injection compression molding). Among these, the effects of the present invention can be more effectively obtained by injection molding other than gas injection molding or injection compression molding (press injection), and it is preferable to obtain a molded article by such a molding method. The propylene-based resin composition of the present invention can be molded, as needed, by various molding methods such as blow molding, extrusion molding, compression (press) molding, foam (expansion) molding, sheet molding, thermoforming, stamping molding, and powder molding, thereby obtaining a desired molded product (e.g., an extrusion molded product). Among these, molding methods other than foam (expansion) molding are preferred.

[0078] (2)Applications Applications of injection-molded articles obtained from the propylene-based resin composition of the present invention include, for example, parts for home appliances such as rice cookers, vacuum cleaners, washing machines, refrigerators, electric fans, and air conditioners; parts for housing facilities such as vanities, ventilation fans, toilet seats, toilet covers, and housings for devices used as accessories; general batteries and battery peripheral parts; and battery peripheral parts for electric vehicles. [Example]

[0079] The present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples. The evaluation methods and materials used in the examples are as follows.

[0080] 1. Evaluation Method 1) MFR of the resin part The melt flow rate (MFR) of the resin portion was measured in accordance with JIS K7210 at a test temperature of 230°C and a load of 2.16 kg. In this example, when a plurality of polypropylene resins were mixed and used as the polypropylene resin (A), the melt flow rate (MFR A ) was calculated according to the logarithmic additivity rule using the following formula (1). log(MFR A ) = {(% by weight of component (PP-A) × log (MFR of component (PP-A)) + (% by weight of component (PP-B) × log (MFR of component (PP-B)) + (% by weight of component (PP-C) × log (MFR of component (PP-C))} / 100 Formula (1)

[0081] 2) Flame retardancy test (fire resistance evaluation) 2)-1. Flame-resistant time evaluation Using an injection molding machine (Toshiba EC180, equipped with a long fiber screw), a 170 x 170 mm test piece (thickness: 3.0 mm) was molded under the following conditions: cylinder temperature: 200°C, mold temperature: 40°C, injection pressure: 60 MPa, injection speed: 60 mm / sec, and a flame retardancy test was conducted. The details of the flame retardancy test are as follows: A 125mm flame, as used in UL94 5VA, was applied to the flat surface of the test piece from below. At this time, the distance between the test piece and the burner nozzle was 100mm. In this state, the flame was applied for 15 minutes, and the time until the flame penetrated was measured and recorded as the flame resistance time in the flame protection test. If the flame did not penetrate after 15 minutes of continued flame application, the flame was stopped at that point. The evaluation of the flame resistance time is as follows. ◎: The flame did not penetrate within 15 minutes of exposure to flame (denoted as >900) 〇: The flame penetrated between 10 and 15 minutes △: The flame penetrated within 5 to 10 minutes ×: Flame penetrated in less than 5 minutes

[0082] 2)-2. Shape retention evaluation For samples that were not penetrated by flame for 15 minutes in the flame-proofing test, the shape retention of the sample was evaluated 15 minutes after exposure to flame in the flame-proofing test. The shape retention was evaluated as follows. ◎: No cracks or fissures were found on the flame-contact surface ○: Cracks less than 1 cm in size are observed in the vertical direction of the flame contact surface (below the flame contact surface) △: Cracks of 1cm or more but less than 8cm in the vertical direction (below the flame surface) of the flame surface are observed ×: Cracks of 8 cm or more in the vertical direction (below the flame surface) of the flame surface are observed -: In the flame-proofing test, the flame penetrated in less than 15 minutes, so it was not included in the evaluation of shape retention.

[0083] 2)-3. Overall evaluation of flame retardancy Based on the above evaluation of flame-proofing time and shape retention, a comprehensive evaluation was made as follows. ◎: When both judgments are judged as ◎ 〇: When flame resistance time is judged as ◎ and shape retention is judged as 〇 or △ △: When the flame resistance time is judged as 〇 ×: Flame-resistant time is judged as △ or ×, or shape retention is judged as ×

[0084] 3) Fluidity (spiral flow) evaluation Using an injection molding machine (Toshiba EC180, long fiber screw installed), injection molding was performed using a 20mm wide x 2.5mm thick spiral flow mold under the following conditions: cylinder temperature: 200°C, mold temperature: 40°C, injection pressure: 60MPa, injection speed: 50mm / sec. The length of the molded specimen was measured, and the longer the length, the higher the fluidity. The fluidity was evaluated as follows: ◎: 420mm or more 〇: 370mm or more and less than 420mm △: 320mm or more and less than 370mm ×: Less than 320mm

[0085] 4) Mechanical properties (bending strength) Measurements were made at 23°C in accordance with JIS K7203. The molded product dimensions were 90 x 10 x 4 mm, and the unit was MPa. The mechanical properties were evaluated as follows: ◎: When the bending strength is 190 MPa or more ○: When the bending strength is 180 MPa or more but less than 190 MPa △: When the bending strength is 170 MPa or more and less than 180 MPa ×: When the bending strength is less than 170 MPa

[0086] 5) Overall rating Based on the overall evaluation of flame retardancy, the evaluation of fluidity, and the judgment of mechanical properties, the overall evaluation was carried out as follows. ◎: No × or △ in all judgments, only 〇 and ◎ judgments ○: No × in all judgments, all judgments are △ or higher, and at least one judgment is ○ or higher △: If all judgments are △ ×: At least one of the judgments is × In the comparative examples, if any of the above evaluations was judged to be "x", the overall evaluation was also determined to be "x", so there were cases in which other evaluations were not performed.

[0087] 2.Material Polypropylene resin (A) (A-1) Novatec PP series, MA1B (propylene homopolymer, MFR: 20g / 10min), manufactured by Japan Polypropylene Corporation (A-2) Novatec PP series, SA08A (propylene homopolymer, MFR: 75g / 10min), manufactured by Japan Polypropylene Corporation (A-3) Novatec PP series, MA3 (propylene homopolymer, MFR: 11 g / 10 min), manufactured by Japan Polypropylene Corporation (A-4) Novatec PP series, MA04C (propylene homopolymer, MFR: 40g / 10min), manufactured by Japan Polypropylene Corporation (A-5) Novatec PP series, FY6H (propylene homopolymer, MFR: 2g / 10min), manufactured by Japan Polypropylene Corporation (A-6) The above (A-3) was mixed with an organic peroxide to adjust the MFR of (A-3), and used as (A-6) (propylene homopolymer, MFR: 150 g / 10 min). (A-7) The above (A-3) was mixed with an organic peroxide to adjust the MFR of (A-3), and used as (A-7) (propylene homopolymer, MFR: 650 g / 10 min). Organic flame retardant (B) (B-1) ADEKA Corporation, FP2500S (a phosphorus-based flame retardant containing polyphosphate) Fiber (C) (C-1) Glass fiber: manufactured by Nittobo Co., Ltd., RS2300, 2300TEX, fiber diameter 17 μm Other additives (D) Other additives (D) used included antioxidants (D-1: BASF's Irganox 1010), (D-2: ADEKA's Irgafos 168), and maleic anhydride-modified polypropylene (D-3: Arkema's OREVAC CA100).

[0088] 3. Preparation of various master batches (MB) 1) Flame-retardant masterbatch: Preparation of flame-retardant MB-I and MB-II Polypropylene resin (A), phosphorus-based flame retardant (B), and other additives (D) were blended in the proportions shown in Table 1 and mixed at room temperature for 3 minutes using a high-speed agitator mixer (Henschel Mixer, product name). The mixture was then melt-kneaded and extruded using a twin-screw extruder, passed through a cold water bath, and then the strands were cut using a strand cutter to obtain pellets of the flame-retardant masterbatch.

[0089] [Table 1]

[0090] 2) Fiber Masterbatch: Preparation of Fiber MB-I and II Fibers MB-I and MB-II were prepared by transferring glass fibers (C) from a fiber rack to a resin impregnation bath containing polypropylene-based resin (A-6) or (A-7) heated to 270°C. The glass fiber bundles were impregnated with the polypropylene-based resin (A-6) or (A-7). The impregnation bath then pulled the bundles through a circular nozzle, cooled, and cut them into pellets of fiber MB-I (10 mm long) and fiber MB-II (6 mm long). The MFR of the polypropylene-based resin (A-6) or (A-7) in the impregnation bath and the weight ratio of the polypropylene-based resin (A-6) or (A-7) to the glass fibers in each fiber MB were as shown in Table 2. The additives D-1, D-2, and D-3 were blended in amounts of 0.1 part by weight, 0.05 part by weight, and 0.4 part by weight per 100 parts by weight of the polypropylene-based resin (A-6) or (A-7) in the impregnation bath.

[0091] [Table 2]

[0092] 3. Preparation of test specimens 1) Examples 1 to 16 and Comparative Examples 1 to 8 The obtained masterbatches and polypropylene resins were mixed in the ratios shown in the dry blend ratio column in Tables 3 and 4, and then molded in an injection molding machine and evaluated according to the above evaluation methods. The final compositions of the propylene resin compositions and the obtained evaluation results are shown in Tables 3 and 4.

[0093] [Table 3]

[0094] [Table 4]

[0095] 4. Evaluation Results From the results shown in Tables 3 and 4, the melt flow rate (MFR AIt can be seen that the lower the value of MFR ) of the resin part is, the more improved the fire resistance and flame retardancy are. A It can be seen that the fire resistance and flame retardancy improve as the melt flow rate (MFR A ) is at the same level, but increasing the proportion of flame retardant improves the fire resistance and flame blocking properties. A It is clear that controlling both parameters is important for fire resistance and flame retardancy. On the other hand, the melt flow rate (MFR) of the resin part for a given amount of flame retardant A If the melt flow rate (MFR) of the resin is reduced to a certain level, the fluidity will decrease, which will hinder the production of actual products. Therefore, in this invention, the melt flow rate (MFR) of the resin part is set by taking into consideration the balance between fire resistance, flame retardancy, and fluidity. A ) needs to be optimized by adjusting the amount of fiber and the amount of flame retardant. In other words, Comparative Example 1 has good fire resistance and flame retardancy, but its fluidity is low, and for practical use, the melt flow rate (MFR A ) needs to be increased. Furthermore, the present invention proposes a composition that is excellent not only in fire resistance, flame protection, and fluidity but also in mechanical strength, and when the concentration of fiber (C) is reduced, for example, as in Comparative Example 8, the mechanical strength decreases. Therefore, in order to propose a composition that is excellent in balance between fire resistance, flame protection, fluidity, and mechanical properties, the concentration of fiber (C) needs to be 30% by weight or more.

[0096] These examples and comparative examples demonstrate that the composition defined in the present application can achieve both high levels of fire resistance and flame retardancy and good fluidity.

Claims

1. A propylene-based resin composition comprising a polypropylene-based resin (A) that satisfies the following requirement (A1), a flame retardant (B) that satisfies the following requirement (B1), and a fiber (C) that satisfies the following requirement (C1), and characterized in that the composition satisfies the following conditions 1 and 2: Requirement (A1) The polypropylene resin (A) contains at least one propylene polymer selected from the group consisting of propylene homopolymers, propylene random copolymers, and propylene block copolymers. Requirement (B1) The flame retardant (B) is an organic flame retardant. Requirement (C1) The fiber (C) is a glass fiber. Condition 1 The propylene-based resin composition contains 24 to 65% by weight of a polypropylene-based resin (A), 5 to 26% by weight of a flame retardant (B), and 30 to 50% by weight of fibers (C) (wherein the total of the polypropylene-based resin (A), the flame retardant (B), and the fibers (C) is 100% by weight). Condition 2 The melt flow rate (MFR, 230°C, 2.16 kg load) of the polypropylene resin (A) and the content of the flame retardant (B) (where the total of the polypropylene resin (A), the flame retardant (B), and the fiber (C) is taken as 100% by weight) satisfy either (Condition 2-1) or (Condition 2-2) below. (Condition 2-1) The content of the flame retardant (B) (unit: weight %, where the total of the polypropylene-based resin (A), the flame retardant (B), and the fiber (C) is 100 weight %) is 5 weight % or more and less than 18 weight %, and the melt flow rate (MFR, 230°C, 2.16 kg load) of the polypropylene-based resin (A) is 75 g / 10 min or less. (Condition 2-2) The content of the flame retardant (B) (unit: weight %, where the total of the polypropylene-based resin (A), the flame retardant (B), and the fiber (C) is 100 weight %) is 18 weight % or more and 26 weight % or less, and the melt flow rate (MFR, 230°C, 2.16 kg load) of the polypropylene-based resin (A) is 105 g / 10 min or less.

2. The propylene-based resin composition according to claim 1, wherein the polypropylene-based resin (A) further satisfies the following requirement (A2): Requirements (A2) The polypropylene resin (A) contains at least two types of polypropylene resins (Aa) and (Ab), and the melt flow rate (MFR, 230°C, 2.16 kg load) of the polypropylene resin (Aa) is in the range of 60 to 2000 / 10 min.

3. The propylene-based resin composition according to claim 1, wherein the fibers (C) further satisfy the following requirement (C2): Requirement (C2) As the fiber (C), glass fiber having a fiber length of 1 to 20 mm is used.

4. 2. The propylene-based resin composition according to claim 1, wherein the flame retardant (B) is a phosphorus-based flame retardant.

5. 5. The propylene-based resin composition according to claim 4, wherein the flame retardant (B) is a polyphosphate.

6. A molded article obtained from the propylene-based resin composition according to any one of claims 1 to 5.

Images