Resin composition and method for producing the same

Abstract

To provide a resin composition of a polyolefin resin excellent in flame resistance in spite of halogen-free, and excellent in mechanical characteristics such as toughness and rigidity of an obtained molded product, and a production method of the same.SOLUTION: A resin composition of the present invention is a halogen-free resin composition containing a polyolefin resin containing 0.05-2.5 mass% of a phosphorous compound as a content of phosphorus, 0.05-5 mass% of a NOR-type hindered amine, and 5-50 mass% of an inorganic filler to a total amount of the resin composition, respectively, where the DTA curve obtained by differential thermal analysis of the inorganic filler has a part indicating endotherm in a temperature range of 180-500°C, and the ratio of a particle number of particles having a maximum diameter of 300 μm or larger to a particle number of particles having a maximum diameter of 100 μm or larger in the inorganic filler is 1 / 5 or less, or there is no particle having a maximum diameter of 100 μm or larger.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a resin composition and a method for producing the same. More specifically, the present invention relates to a polyolefin resin resin composition that is halogen-free, yet has excellent flame retardancy, and the resulting molded article has excellent mechanical properties in terms of toughness and rigidity, and to a method for producing the same. [Background technology]

[0002] Polyolefin resins, such as polypropylene, are used in a variety of applications because they produce little carbon dioxide during manufacturing, are lightweight, have excellent chemical resistance, possess high elongation, and are inexpensive.

[0003] On the other hand, because polyolefin resins are highly flammable, when flame retardancy is required for molded products, a resin composition for molding containing a large amount of flame retardant is used. However, the addition of flame retardants can sometimes impair the aforementioned characteristics of polyolefin resins. Conventionally, various flame retardants such as halogen compounds, phosphorus compounds, and metal hydrates have been known.

[0004] However, since halogenated compounds are harmful, there is a need for halogen-free flame retardancy technologies. For example, a known technology uses metal hydroxides as flame retardants to achieve halogen-free flame retardancy. However, in this case, a large amount of metal hydroxide must be added to obtain sufficient flame retardancy, which leads to a decrease in the mechanical strength of the resulting molded product.

[0005] Among hindered amine light stabilizers known as light stabilizers, a NOR-type hindered amine compound (hereinafter sometimes referred to as "NOR-type HALS") is used as a flame retardant. For example, Patent Document 1 describes a technique for suppressing a decrease in the toughness of a molded product obtained by blending an elastomer while achieving flame retardancy by using a combination of a phosphorus compound and NOR-type HALS. However, the technique described in Patent Document 1 has a problem in that sufficient rigidity cannot be imparted to the molded product.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0007] The present invention has been made in view of the above problems and situations, and the problem to be solved is to provide a resin composition of a polyolefin resin that is halogen-free, has excellent flame retardancy, and the obtained molded product has excellent mechanical properties of toughness and rigidity, and a method for producing the same.

Means for Solving the Problems

[0008] In order to solve the above problems, the present inventor has found that by containing a phosphorus compound, a NOR-type hindered amine, and an inorganic filler having a predetermined heat absorption property and particle size characteristics in a specific ratio in a halogen-free resin composition containing a polyolefin resin, a molded product excellent in mechanical properties of toughness and rigidity and flame retardancy can be produced, and thus the present invention has been achieved. That is, the above problems according to the present invention are solved by the following means.

[0009] 1. A halogen-free resin composition containing a polyolefin resin, The inorganic filler includes an endothermic inorganic filler and a non-endothermic inorganic filler. The aforementioned endothermic inorganic filler has a DTA curve obtained by differential thermal analysis that shows an endothermic portion in the temperature range of 180 to 500°C. The aforementioned non-endothermic inorganic filler does not have a portion of the DTA curve obtained by differential thermal analysis that shows endothermic activity in the temperature range of 180 to 500°C. The aforementioned endothermic inorganic filler is at least one selected from aluminum hydroxide particles and magnesium hydroxide particles. The non-heat-absorbing inorganic filler is at least one selected from wollastonite particles, calcium carbonate particles, mica particles, talc particles, kaolin particles, and glass particles. With respect to the total amount of the aforementioned resin composition, The phosphorus compound is present in a phosphorus content of 0.05 to 2.5% by mass. NOR-type hindered amine in 0.05 to 5% by mass, and The inorganic filler is 15-50% by mass ,So Each contains, Of the inorganic fillers, the endothermic inorganic filler is contained in an amount of 5 to 25% by mass relative to the total amount of the resin composition. and 、 before A resin composition characterized in that, in the inorganic filler, the ratio of the number of particles with a maximum diameter of 300 μm or more to the number of particles with a maximum diameter of 100 μm or more is 1 / 5 or less, or no particles with a maximum diameter of 100 μm or more are present.

[0011] 2 The first is characterized in that the polyolefin resin is a polypropylene-based resin. In the section The resin composition described.

[0012] 3 The first claim is characterized in that the phosphorus compound includes a phosphate ester compound. or The In item 2 The resin composition described.

[0013] 4 The DTA curve obtained by differential thermal analysis under a heating condition of 0.10°C / min has a portion exhibiting endothermic activity within the temperature range of 180 to 350°C, as described in the first to third paragraphs. 3 A resin composition as described in any one of the items up to item number.

[0014] 5 With respect to the total amount of the resin composition, The phosphorus compound is present in an amount of 0.1 to 1.5% by mass as the phosphorus content. The aforementioned NOR-type hindered amine is added in an amount of 0.1 to 2% by mass. The inorganic filler is 1 5 Each contains approximately 30% by mass, and 、 before The inorganic filler described is characterized in that it satisfies either (a) or (b) below. 4 A resin composition as described in any one of the items up to item number. (a) The ratio of the number of particles with a maximum diameter of 200 μm or more to the number of particles with a maximum diameter of 100 μm or more is 1 / 10 or less, or there are no particles with a maximum diameter of 100 μm or more, The ratio of the number of particles with a maximum diameter of less than 5 μm to the number of particles with a maximum diameter of 5 μm or more is 10 or greater. (b) No particles with a maximum diameter of 5 μm or more are present.

[0015] 6 Furthermore, the first to third paragraphs are characterized by containing fatty acids or salts thereof. 5 A resin composition as described in any one of the items up to item number.

[0016] 7 Articles 1 through 1 6 A method for producing a resin composition described in any one of the items up to item, A method for producing a resin composition, characterized by comprising the step of kneading raw material components, including the polyolefin resin, the phosphorus compound, the NOR-type hindered amine, and the inorganic filler, using a twin-screw extruder. [Effects of the Invention]

[0017] The present invention provides a polyolefin resin composition that is halogen-free, yet exhibits excellent flame retardancy, and the resulting molded article has excellent mechanical properties in terms of toughness and rigidity, as well as a method for producing the same. The mechanism by which the effects of this invention manifest or act is presumed to be as follows.

[0018] The combustion of plastics involves multiple processes, but it is difficult to achieve high flame retardancy by completely blocking one of these processes while maintaining mechanical strength such as toughness and rigidity. The inventors have found that by suppressing multiple processes through multiple flame retardant mechanisms, high flame retardancy can be imparted to molded articles of halogen-free polyolefin resin compositions, and that this method also improves the mechanical strength such as toughness and rigidity of the molded articles.

[0019] Specifically, phosphorus compounds have flame-retardant effects through radical trapping and plasticization, while NOR-type HALS have flame-retardant effects through radical trapping and reduction of molecular weight during combustion. On the other hand, increasing the content of these compounds in the polyolefin resin composition to obtain sufficient flame retardancy leads to a decrease in the mechanical properties of molded products and an increase in costs.

[0020] By incorporating an endothermic inorganic filler into a polyolefin resin composition, a flame-retardant effect due to endothermic properties, which is not present in phosphorus compounds and NOR-type HALS, can be imparted. Furthermore, as described below, by adjusting the particle size distribution of the inorganic filler, the drip characteristics during combustion of the molded product can be adjusted, thereby further improving flame retardancy.

[0021] Inorganic fillers are heavier than polyolefin resins and possess both the effect of increasing melt tension, thus creating crack sources for fracture and promoting dripping, and the effect of increasing melt viscosity, thereby suppressing dripping. By adjusting the particle size of the inorganic filler within a predetermined range, the number of crack sources and melt viscosity can be balanced, thereby imparting a drip-promoting effect to the molded product. Specifically, promoting dripping makes it easier for ignition sources to fall, thus aiding in fire extinguishing. Furthermore, within the above range, mechanical strength can also be provided.

[0022] In this invention, by incorporating specific amounts of a phosphorus compound, NOR-type HALS, and an inorganic filler having predetermined endothermic properties and particle size characteristics, it is possible to provide a polyolefin resin composition that is halogen-free yet highly flame-retardant, and in which the resulting molded article exhibits excellent mechanical properties in terms of toughness and rigidity. [Brief explanation of the drawing]

[0023] [Figure 1] Image of a cross-section of the resin composition obtained in Example 1, taken with an electron microscope (300x magnification). [Figure 2] Image of a cross-section of the resin composition obtained in Example 1, taken with an electron microscope (5000x magnification). [Figure 3] DTA curve obtained by differential thermal analysis of aluminum hydroxide particles (KH-101) [Figure 4] DTA curve obtained by differential thermal analysis of calcium carbonate particles (Calcium P) [Figure 5] DTA curve obtained by differential thermal analysis of the resin composition obtained in Example 1 [Modes for carrying out the invention]

[0024] The resin composition of the present invention is a halogen-free resin composition containing a polyolefin resin, wherein the total amount of the resin composition contains 0.05 to 2.5% by mass of a phosphorus compound, 0.05 to 5% by mass of a NOR-type hindered amine, and 5 to 50% by mass of an inorganic filler, and the DTA curve obtained by differential thermal analysis of the inorganic filler has an endothermic portion in the temperature range of 180 to 500°C, and the ratio of the number of particles with a maximum diameter of 300 μm or more to the number of particles with a maximum diameter of 100 μm or more in the inorganic filler is 1 / 5 or less, or there are no particles with a maximum diameter of 100 μm or more. This feature is a technical feature common to each of the embodiments described below.

[0025] As an embodiment of the resin composition of the present invention, from the viewpoint of exhibiting the effects of the present invention, it is preferable that the inorganic filler comprises at least one selected from aluminum hydroxide particles, boehmite particles, magnesium hydroxide particles, and hydromagnesite particles, and at least one selected from wollastonite particles, talc particles, mica particles, glass particles, kaolin particles, magnesium sulfate particles, calcium carbonate particles, and silica particles.

[0026] In embodiments of the resin composition of the present invention, it is preferable that the polyolefin resin is a polypropylene-based resin, as this more pronounced effect of the present invention is exhibited.

[0027] As an embodiment of the resin composition of the present invention, from the viewpoint of exhibiting the effects of the present invention, it is preferable that the phosphorus compound includes a phosphate ester compound.

[0028] As an embodiment of the resin composition of the present invention, from the viewpoint of exhibiting the effects of the present invention, it is preferable that the DTA curve obtained by differential thermal analysis of the resin composition under a heating condition of 10°C / min has a portion that exhibits endothermic activity within the temperature range of 180 to 350°C.

[0029] As an embodiment of the resin composition of the present invention, from the viewpoint of exhibiting the effects of the present invention, it is preferable that the resin composition contains 0.1 to 1.5% by mass of the phosphorus compound as a phosphorus content, 0.1 to 2% by mass of the NOR-type hindered amine, and 10 to 30% by mass of the inorganic filler, wherein the inorganic filler contains 5% by mass or more of an endothermic inorganic filler, the DTA curve obtained by differential thermal analysis having an endothermic portion in the temperature range of 180 to 500°C, and the inorganic filler satisfies either (a) or (b) below.

[0030] (a) The ratio of the number of particles with a maximum diameter of 200 μm or more to the number of particles with a maximum diameter of 100 μm or more is 1 / 10 or less, or there are no particles with a maximum diameter of 100 μm or more, The ratio of the number of particles with a maximum diameter of less than 5 μm to the number of particles with a maximum diameter of 5 μm or more is 10 or greater. (b) No particles with a maximum diameter of 5 μm or more are present.

[0031] The inorganic filler contained in the resin composition of the present invention contains at least the above-mentioned endothermic inorganic filler. The inorganic filler contained in the resin composition of the present invention contains the above-mentioned endothermic inorganic filler, so that the DTA curve obtained by differential thermal analysis has a portion that shows endothermic activity in the temperature range of 180 to 500°C. The inorganic filler may further contain a non-endothermic inorganic filler that does not have a portion that shows endothermic activity in the temperature range of 180 to 500°C in the DTA curve obtained by differential thermal analysis, in order to set the particle size of the inorganic filler within a predetermined range.

[0032] As an embodiment of the resin composition of the present invention, it is preferable that it further contains a fatty acid or a salt thereof, from the viewpoint of exhibiting the effects of the present invention.

[0033] The present invention relates to a method for producing a resin composition, comprising the step of kneading raw material components, including the polyolefin resin, the phosphorus compound, the NOR-type hindered amine, and the inorganic filler, using a twin-screw extruder.

[0034] The present invention, its components, and embodiments and models for carrying out the present invention will be described in detail below. In this application, "~" is used to mean that the numerical values ​​before and after it are included as the lower limit and upper limit.

[0035] [Resin composition] The resin composition of the present invention is a halogen-free resin composition containing a polyolefin resin, wherein the resin composition contains 0.05 to 2.5% by mass of a phosphorus compound, 0.05 to 5% by mass of a NOR-type hindered amine, and 5 to 50% by mass of an inorganic filler, respectively, based on the total amount of the resin composition, and the DTA curve obtained by differential thermal analysis of the inorganic filler has a portion that shows endothermic activity in the temperature range of 180 to 500°C, and the ratio of the number of particles with a maximum diameter of 300 μm or more to the number of particles with a maximum diameter of 100 μm or more in the inorganic filler is 1 / 5 or less, or there are no particles with a maximum diameter of 100 μm or more.

[0036] In the following explanation, phosphorus compounds may be referred to as component (A), NOR-type hindered amines as component (B), and inorganic fillers that satisfy the requirements of (1) and (2) below as component (C). (1) The DTA curve obtained by differential thermal analysis has a portion that shows endothermic activity in the temperature range of 180 to 500°C. (2) The ratio of the number of particles with a maximum diameter of 300 μm or more to the number of particles with a maximum diameter of 100 μm or more is 1 / 5 or less, or there are no particles with a maximum diameter of 100 μm or more.

[0037] The resin composition of the present invention is a halogen-free resin composition. In the present invention, a resin composition is "halogen-free" to mean, for example, that the chlorine content is 900 ppm by mass or less, the bromine content is 900 ppm by mass or less, and the total content of chlorine and bromine is 1500 ppm by mass or less, based on the total amount of the resin composition.

[0038] The halogen element content in a resin composition can be quantified, for example, by flask combustion ion chromatography, wavelength-dispersive X-ray analysis, or inductively coupled plasma emission spectroscopy.

[0039] The resin composition of the present invention may optionally contain fatty acids or their salts in addition to the above-mentioned components, as long as it does not impair the effects of the present invention. Furthermore, the resin composition of the present invention may optionally contain other resins other than polyolefin resins, and various additives commonly found in resin compositions, as long as it does not impair the effects of the present invention. The components of the resin composition of the present invention will be described below.

[0040] (Polyolefin resin) Polyolefin resins are homopolymers or copolymers polymerized with olefins as the main monomer component. In this specification, "olefin" refers to an aliphatic chain unsaturated hydrocarbon having one double bond.

[0041] Here, the main component constituting the resin (polymer) refers to the component that makes up 50% by mass or more of the total monomer components constituting the polymer. Polyolefin resin is a homopolymer or copolymer containing olefin in an amount of 60 to 100% by mass, more preferably 70 to 100% by mass, and even more preferably 80 to 100% by mass of the total monomer components.

[0042] Olefin copolymers include copolymers of olefins with other olefins, or copolymers of olefins with other monomers copolymerizable to olefins. The content of the above other monomers in the polyolefin resin is preferably 30% by mass or less, more preferably 0 to 20% by mass, of the total monomer components.

[0043] As the olefin, α-olefins having 2 to 12 carbon atoms are preferred. Examples of olefins include ethylene, propylene, 1-butene, isobutene, 1-pentene, 3-methyl-1-butene, 1-hexene, 1-octene, and 1-decene. When polymerizing polyolefin resins, one type of olefin may be used alone, or two or more types may be used in combination.

[0044] Other monomers copolymerizable with olefins include, for example, elastomer components having unsaturated bonds. Specific examples of other monomers include cyclic olefins such as cyclopentene and norbornene, and dienes such as 1,4-hexadiene and 5-ethylidene-2-norbornene. Furthermore, monomers such as vinyl acetate, styrene, (meth)acrylic acid and its derivatives, vinyl ethers, maleic anhydride, carbon monoxide, and N-vinylcarbazole may also be used. These other monomers may be used individually or in combination of two or more during the polymerization of the polyolefin resin. Note that "(meth)acrylic acid" refers to at least one of acrylic acid and methacrylic acid.

[0045] Specific examples of polyolefin resins include polyethylene resins mainly composed of ethylene, such as high-density polyethylene (HDPE), low-density polyethylene (LDPE), and linear low-density polyethylene (LLDPE); polypropylene resins mainly composed of propylene, such as polypropylene (propylene homopolymer), ethylene-propylene copolymer, propylene-butene copolymer, ethylene-propylene-butene copolymer, and ethylene-propylene-diene copolymer; polybutene; and polypentene.

[0046] Specific examples of polyolefin resins include ethylene-vinyl acetate copolymers (EVA), ethylene-ethyl acrylate copolymers, polyketones, and copolymers produced with metallocene catalysts. Furthermore, these polymers are also included if they are chemically reacted or modified, specifically ionomer resins, saponified EVA, and olefin-based elastomers produced using dynamic vulcanization in an extruder.

[0047] As the polyolefin resin, polyethylene-based resins and polypropylene-based resins are preferred, with polypropylene-based resins being more preferred. The stereoregularity of the structure derived from propylene in the polypropylene-based resin may be isotactic, syndiotactic, or atactic. As the polypropylene-based resin, isotactic polypropylene or its block type is even more preferred.

[0048] The resin composition of the present invention may contain one polyolefin resin or two or more polyolefin resins. Commercially available polyolefin resins may be used.

[0049] The polyolefin resin content in the resin composition of the present invention is the amount obtained by subtracting the content of component (A), component (B), component (C), and any other components optionally included in the resin composition. The polyolefin resin content relative to the total amount of the resin composition can be, for example, in the range of 20 to 90% by mass, and more preferably in the range of 30 to 80% by mass.

[0050] (Other resins) The resin composition of the present invention may contain resins other than polyolefin resins. Examples of these other resins include thermoplastic resins, specifically, polyester resins such as polystyrene resin, acrylonitrile-butadiene-styrene copolymer (ABS resin), polycarbonate resin, and polyethylene terephthalate. These may be used individually or in combination of two or more. Commercially available resins may also be used.

[0051] Furthermore, other resins that function as toughening agents may be used. Toughening agents are used to improve the flexibility, processability, and impact resistance of the resin composition, and are, for example, resins with rubber elasticity. As described above, it is expected that adding toughening agents will reduce rigidity as a side effect. Therefore, when using them, care should be taken to adjust the content so as not to impair the effects of the present invention.

[0052] The resin used as a toughening agent is preferably an elastomer mainly composed of olefin-derived structural units, such as ethylene propylene diene rubber (EPDM).

[0053] In addition to the above, thermoplastic elastomers can also be used, and it is particularly preferable that they contain constituent units derived from olefins. Examples of thermoplastic elastomers include methyl methacrylate-butadiene-styrene copolymer (MBS), acrylonitrile-butadiene-styrene copolymer (ABS), styrene-butadiene-styrene copolymer (SBS), styrene-ethylene-butylene-styrene block copolymer (SEBS), ethylene-octene copolymer (EOR), and butyl acrylate-methyl methacrylate copolymer. Among these, it is preferable that the toughening agent is one or more selected from the group consisting of SEBS and EOR, from the viewpoint of compatibility and flame retardancy of the resin composition and the dispersibility of the thermoplastic elastomer in the resin composition. Toughening agents that have the effect of imparting compatibility to the resin composition can also be used as compatibilizers as described later. Toughening agents may be used alone or in combination of two or more.

[0054] The content of other resins in the resin composition of the present invention can be in the range of 0 to 20 parts by mass per 100 parts by mass of polyolefin resin, more preferably in the range of 0 to 10 parts by mass, and it is particularly preferable that no other resins are included.

[0055] (Component (A)) Component (A) is a phosphorus compound. In the resin composition of the present invention, component (A) primarily acts as a flame retardant. As described above, phosphorus compounds have flame retardant effects through radical trapping and plasticization. In addition, component (A) has the effect of reducing the melt viscosity of the resin composition during molding, thereby improving moldability.

[0056] The content of component (A) is 0.05 to 2.5% by mass as the phosphorus content relative to the total amount of the resin composition of the present invention. If the content of component (A) is less than 0.05% by mass as the phosphorus content, the flame retardancy of the molded article will not be sufficient, and if it is greater than 2.5% by mass, the mechanical strength (toughness and rigidity) of the molded article will not be sufficient. The content of component (A) relative to the total amount of the resin composition is preferably in the range of 0.1 to 1.5% by mass as the phosphorus content, and more preferably in the range of 0.15 to 0.65% by mass.

[0057] Component (A), a phosphorus compound, has poor compatibility with polyolefin resin, making it prone to separation during melting. The separated component bleeds out and remains on the surface of the molded product, often leading to a deterioration in appearance. If the phosphorus content relative to the total amount of the resin composition is 2.5% by mass or less, the deterioration in appearance caused by the bleed-out of component (A) can be suppressed.

[0058] The phosphorus content (mass%) relative to the total amount of the above resin composition can be measured, for example, using an energy-dispersive X-ray fluorescence spectrometer (e.g., JSX-1000S (manufactured by JEOL Ltd.)), wavelength-dispersive X-ray spectroscopy (ZSX PrimusIV (Rigaku)), or inductively coupled plasma emission spectroscopy.

[0059] Examples of phosphorus compounds include phosphinic acid, phosphonic acid, salts with metals such as phosphoric acid and ammonium, and ester compounds of phosphinic acid, phosphonic acid, and phosphoric acid. Among these, phosphate ester compounds (described in detail later) are preferred as component (A2) from the viewpoint of flame retardancy.

[0060] Specifically, the above-mentioned salts include phosphinate metal salts, particularly aluminum phosphinate and zinc phosphinate; phosphonate metal salts, particularly aluminum phosphonate, calcium phosphonate, and zinc phosphonate; and hydrates of equivalent phosphonate metal salts, ammonium phosphate, and ammonium polyphosphate.

[0061] Examples of phosphinic acid ester compounds include dimethylphosphinic acid, methylethylphosphinic acid, methylpropylphosphinic acid, diethylphosphinic acid, dioctylphosphinic acid, phenylphosphinic acid, diethylphenylphosphinic acid, diphenylphosphinic acid, and bis(4-methoxyphenyl)phosphinic acid.

[0062] Examples of phosphonic acid ester compounds include methylphosphonic acid, dimethyl methylphosphonic acid, diethyl methylphosphonic acid, ethylphosphonic acid, propylphosphonic acid, butylphosphonic acid, 2-methyl-propylphosphonic acid, t-butylphosphonic acid, 2,3-dimethylbutylphosphonic acid, octylphosphonic acid, phenylphosphonic acid, and dioctylphenylphosphonate.

[0063] In addition, as phosphorus compounds other than those mentioned above, derivatives of 9,10-dihydro-9-oxa-10-phosphaphenanthrene 10-oxide (DOPO), polyphosphonates (e.g., Nofia® HM1100 (manufactured by FRXPolymers (Chelmsford, USA))), zinc bis(diethylphosphinate), aluminum tris(diethylphosphinate), melamine phosphate, melamine pyrophosphate, melamine polyphosphate, melamine poly(aluminum phosphate), melamine poly(zinc phosphate), methylphosphonic acid melamine salt, guanylurea phosphate, guanidine phosphate, ethylenediamine phosphate, and phosphazene compounds, such as phenoxyphosphazene oligomers, may be used as component (A).

[0064] The phosphorus compounds may be used as component (A) either individually or in combination of two or more.

[0065] [Phosphate ester compounds] The phosphate ester compound may be either an aliphatic phosphate ester compound or an aromatic phosphate ester compound, with aromatic phosphate ester compounds being preferred. Using an aromatic phosphate ester compound as component (A) allows for mixing and molding at lower temperatures and with lower shear, which is thought to suppress the thermal decomposition of the endothermic inorganic filler during mixing and molding, thereby reducing the endothermic effect during combustion and making it easier to exhibit flame retardant properties.

[0066] Examples of phosphate ester compounds include monomeric phosphate ester compounds obtained by reacting phosphoric acid with aliphatic or aromatic alcohols, and aromatic condensed phosphate ester compounds which are reaction products of phosphorus oxychloride with divalent phenolic compounds and phenol (or alkylphenol).

[0067] Phosphate ester compounds specifically include trimethyl phosphate (TMP), triethyl phosphate (TEP), tributyl phosphate, triphenyl phosphate (TPP), tricresyl phosphate (TCP), trixylenyl phosphate (TXP), cresyl diphenyl phosphate (CDP), tris(2,4-di-t-butylphenyl) phosphate, distearyl pentaerythritol diphosphate, bis(2,6-di-t-butyl-4-methylphenyl) pentaerythritol diphosphate, bis(2,4-di-t-butylphenyl) pentaerythritol diphosphate, resorcinol bis-dixylenyl phosphate, resorcinol bis-diphenyl phosphate, bisphenol A bis-diphenyl phosphate (BADP), bisphenol A bis-dicresyl phosphate, biphenol A bis-diphenyl phosphate, and biphenol A bis-dixylenyl phosphate.

[0068] Furthermore, from the viewpoint of heat resistance and other factors, the phosphate ester compound is preferably a condensed phosphate ester compound. Examples of condensed phosphate ester compounds include aromatic condensed phosphate ester compounds represented by the following chemical formula (A2).

[0069] [Chemical formula]

[0070] In the above formula (A2), R 1 ~R 5 are each independently a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, a cycloalkyl group having 3 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, or an alkoxy group having 1 to 10 carbon atoms, and R 1 ~R 5 may be the same or different. When there are a plurality (5) of R 1 they may be the same as or different from each other. When there are a plurality (4 to 5) of each of R 2 , R 3 , R 4 and R 5 the same applies. n is an integer from 1 to 30, preferably an integer from 1 to 10.

[0071] Examples of the above alkyl group include methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, sec-butyl group, tert-butyl group, amyl group, tert-amyl group, hexyl group, 2-ethylhexyl group, n-octyl group, nonyl group, decyl group, etc.

[0072] Examples of the above cycloalkyl group include cyclohexyl group, etc. Examples of the above aryl group include phenyl group, cresyl group, xylyl group, 2,6-xylyl group, 2,4,6-trimethylphenyl group, butylphenyl group, nonylphenyl group, etc.

[0073] Examples of the above alkoxy group include methoxy group, ethoxy group, propoxy group, butoxy group, etc.

[0074] Aromatic condensed phosphate compounds are reaction products of phosphorus oxychloride, a divalent phenolic compound, and phenol (or alkylphenol), as described above. The aromatic condensed phosphate compound represented by formula (A2) is a compound in which the divalent phenolic compound is resocinol (hereinafter also referred to as "resosinol compound") which may have substituents. The aromatic condensed phosphate compound may also be a compound obtained by using 4,4'-biphenol or bisphenol A (each of which may have substituents) instead of the resocinol compound. Specifically, in formula (A2), aromatic condensed phosphate compounds having a 4,4'-biphenol residue or a bisphenol A residue, each of which may have substituents, instead of the resocinol compound residue can be used in the present invention.

[0075] Commercially available phosphate ester compounds may be used. Examples of commercially available phosphate ester compounds that can be used include PX-200 (resorcinol bis-dixylenyl phosphate), CR-733S (resorcinol bis-diphenyl phosphate), and CR-741 (bisphenol A bis(diphenyl phosphate)), all manufactured by Daihachi Chemical Industry Co., Ltd.

[0076] (Component (B)) Component (B) is a NOR-type HALS. The content of component (B) is 0.05 to 5% by mass of the total amount of the resin composition of the present invention. As described above, component (B) has flame retardant effects such as radical trapping and low molecular weight during combustion.

[0077] If the content of component (B) is less than 0.05% by mass, the flame retardancy of the molded product will not be sufficient, and if it exceeds 5% by mass, the cost will increase significantly. The content of component (B) relative to the total amount of the resin composition is preferably in the range of 0.1 to 2% by mass, and more preferably in the range of 0.2 to 1% by mass.

[0078] Furthermore, component (B), NOR-type HALS, is a well-known light stabilizer, and its addition can impart light resistance to molded products.

[0079] NOR-type HALS are HALS having an alkoxyimino group (>N-OR). An alkoxyimino group is a structure in which the H in the NH portion of an imino group (>NH) remains H, while an NR type has H replaced by an alkyl group (R, which has the same meaning as R in alkoxy group), typically a methyl group, and typically an N-methyl group. This N-alkoxy group easily captures alkyl peroxy radicals (RO2·) and becomes a radical, exhibiting a flame retardant effect. Furthermore, in the resin composition of the present invention, it also functions as the above-mentioned light stabilizer.

[0080] On the other hand, N-methyl type hindered amine compounds or NH type hindered amine compounds exhibit low flame retardancy.

[0081] In the above alkoxy group (-OR), R represents a substituted or unsubstituted saturated or unsaturated hydrocarbon group. Examples of R include alkyl groups, aralkyl groups, and aryl groups. Alkyl groups may be linear, branched, or cyclic, or they may be combinations of these.

[0082] The NOR-type HALS used in the present invention is not particularly limited as long as it has an alkoxyimino group (>N-OR) structure. Specific examples include, for instance, the NOR-type HALS described in Japanese Patent Publication No. 2002-507238, International Publication No. 2005 / 082852, International Publication No. 2008 / 003605, etc., which are preferred examples.

[0083] Examples of NOR-type HALS include compounds whose structure is represented by the following formula (B). Note that if halogen-containing substances remain as impurities, they can be purified as appropriate before use.

[0084] [ka]

[0085] [In formula (B), G1 and G 2 The characters independently represent an alkyl group having 1 to 4 carbon atoms, or together represent a pentamethylene group. Z 1 and Z 2 Each represents a methyl group, or Z 1 and Z 2 These groups together form a crosslinked portion. This crosslinked portion can be further bonded to an organic group via an ester group, ether group, amide group, amino group, carbonyl group, or urethane group. E represents an alkoxy group with 1 to 18 carbon atoms, a cycloalkoxy group with 5 to 12 carbon atoms, an aralkoxy group with 7 to 25 carbon atoms, or an aryloxy group with 6 to 12 carbon atoms.

[0086] As for the NOR-type HALS represented by formula (B), a structure containing many alkoxyimino groups is preferred from the viewpoint of flame retardancy and heat resistance.

[0087] Furthermore, as the NOR-type HALS represented by formula (B), for example, the compound represented by the following formula (1) can be used.

[0088] [ka]

[0089] In the above equation (1), R 1 ~R 4 Each represents either a hydrogen atom or an organic group of the following formula (2). 1 ~R 4 At least one of them is an organic group of formula (2) below.

[0090] [ka]

[0091] In the formula, R 5 R represents an alkyl group having 1 to 17 carbon atoms, a cycloalkyl group having 5 to 10 carbon atoms, a phenyl group, or a phenylalkyl group having 7 to 15 carbon atoms. 6 , R 7 , R8 and R 9 Each of these represents an alkyl group with 1 to 4 carbon atoms. 10 represents a hydrogen atom, or a linear or branched alkyl group having 1 to 12 carbon atoms.

[0092] R 5 Of the C1-C17 alkyl groups, methyl, propyl, or octyl groups are preferred. Of the C5-C10 cycloalkyl groups, cyclohexyl groups are preferred. Of the phenyl or C7-C15 phenylalkyl groups, phenyl groups are preferred. R 6 ~R 9 Among the alkyl groups having 1 to 4 carbon atoms, a methyl group is preferred. R 10 Among linear or branched alkyl groups having 1 to 12 carbon atoms, an n-butyl group is preferred.

[0093] In formula (1), R 1 , R 2 , and R 3 is an organic group of formula (2), or R 1 , R 2 , and R 4 It is preferable that the group is an organic group of formula (2).

[0094] Specific examples of NOR-type HALS include the following compounds. 1-Cyclohexyloxy-2,2,6,6-tetramethyl-4-octadecylaminopiperidine; bis(1-octyloxy-2,2,6,6-tetramethylpiperidine-4-yl)sebacate; 2,4-bis[(1-cyclohexyloxy-2,2,6,6-tetramethylpiperidine-4-yl)butylamino]-6-(2-hydroxyethylamino)-s-triazine; bis(1-cyclohexyloxy-2,2,6,6-tetramethylpiperidine-4-yl)adipate; 4,4'-hexamethylenebis(amino- An oligomeric compound formed by the condensation of 2,2,6,6-tetramethylpiperidine) and 2,4-dichloro-6-[(1-octyloxy-2,2,6,6-tetramethylpiperidine-4-yl)butylamino]-s-triazine, which is terminally capped with 2-chloro-4,6-bis(dibutylamino)-s-triazine; 4,4'-hexamethylenebis(amino-2,2,6,6-tetramethylpiperidine) and 2,4-dichloro-6-[ An oligomeric compound that is a condensation product with (1-cyclohexyloxy-2,2,6,6-tetramethylpiperidine-4-yl)butylamino]-s-triazine; 2,4-bis[(1-cyclohexyloxy-2,2,6,6-piperidine-4-yl)-6-chloro-s-triazine; reaction product of peroxidized 4-butylamino-2,2,6,6-tetramethylpiperidine, 2,4,6-trichloro-s-triazine, cyclohexane, and N,N'-ethane-1,2-diylbis(1,3-propanediamine) (N,N',N'''-Tris{2,4-bis[(1-cyclohexyloxy-2,2,6,6-tetramethylpiperidine-4-yl)n-butylamino]-s-triazine-6-yl}-3,3'-ethylenediiminodipropylamine); bis(1-undecanoxy-2,2,6,6-tetramethylpiperidine-4-yl) carbonate; 1-undecyloxy-2,2,6,6-tetramethylpiperidine-4-one; bis(1-stearyloxy-2,2,6,6-tetramethylpiperidine-4-yl) carbonate.

[0095] Commercially available NOR-type HALS may be used. Examples of commercially available NOR-type HALS include BASF's Flamestab NOR116FF, TINUVIN NOR371FF, TINUVIN XT850FF, TINUVIN XT855FF, TINUVIN PA123, and ADEKA's LA-81, FP-T80, etc. NOR-type HALS may be used individually or in combination of two or more types.

[0096] (Component (C)) Component (C) is an inorganic filler that satisfies the requirements of (1) and (2). (1) The DTA curve obtained by differential thermal analysis has a portion that shows endothermic activity in the temperature range of 180 to 500°C. (2) The ratio of the number of particles with a maximum diameter of 300 μm or more to the number of particles with a maximum diameter of 100 μm or more is 1 / 5 or less, or there are no particles with a maximum diameter of 100 μm or more.

[0097] In (1), "having an endothermic portion" means that, using the baseline of the DTA curve as a reference, if a region where the DTA curve is on the endothermic side is observed in the temperature range of 180 to 500°C, then it is considered to "have an endothermic portion." For example, if the onset region of the endothermic peak is near 500°C on the lower end of the temperature range above 500°C, then it is considered to "have an endothermic portion." Also, if the termination region of the endothermic peak is near 180°C on the higher end of the temperature range above 180°C, then it is considered to "have an endothermic portion."

[0098] Figure 3 shows a DTA curve that satisfies (1). Figure 3 is the DTA curve for aluminum hydroxide particles (KH-101) used in the example. In Figure 3, the endothermic portion (the entire endothermic peak) is shown between 220 and 320°C.

[0099] Figure 4 shows a DTA curve that does not satisfy (1). Figure 4 is the DTA curve for calcium carbonate particles (Calcizu P) used in the example. In Figure 4, it can be seen that there is no endothermic portion between 180 and 500°C. Note that Calsizu P is calcium carbonate particles whose surface has been modified with fatty acids, and the DTA curve in Figure 4 has an exothermic peak with a maximum value around 370°C. This exothermic peak is presumed to be due to the thermal decomposition of the surface modifier in Calsizu P. In the absence of surface modification, the DTA curve of calcium carbonate particles typically does not have either an endothermic or exothermic portion between 180 and 500°C.

[0100] Differential thermal analysis is performed using a differential thermal analyzer such as the DTG-60A (Shimadzu Corporation, simultaneous differential thermal / thermogravimetric analyzer), for example, under heating conditions of 10°C / min in an N2 gas atmosphere.

[0101] Furthermore, even in the case of a mixture of an endothermic inorganic filler (component (C1)) and a non-endothermic inorganic filler (component (C2)) described below, the DTA curve will have an endothermic portion originating from component (C1).

[0102] Furthermore, in (2), the maximum diameter of the inorganic filler is the maximum diameter of the inorganic filler particles measured by observing the resin composition with a scanning electron microscope, for example, JSM-7401F (manufactured by JEOL Ltd.), with the magnification adjusted as appropriate. Here, "maximum particle diameter" is the maximum diameter of the primary particles if the inorganic filler exists in the resin composition as primary particles, and the maximum diameter of the aggregated particles if it exists as aggregated particles. Specifically, in the image of the particle to be measured (primary particle or aggregated particle) observed with a scanning electron microscope, the maximum length obtained by connecting two points on the contour of the particle with a straight line is defined as the maximum diameter of the particle.

[0103] The number of particles with a maximum diameter of 100 μm or more, and the number of particles with a maximum diameter of 300 μm or more, can be counted, for example, in a field of view of a predetermined size, for example, 480 μm × 360 μm, when the resin composition is photographed at a magnification of 300x using a scanning electron microscope. A field of view of 480 μm × 360 μm is four times the size (twice the vertical and horizontal dimensions) of the size that can be obtained in one image (240 μm × 180 μm) when photographed at a magnification of 300x. The field of view is divided into four images (two vertical × two horizontal = four images), and the number of particles of each maximum diameter is counted in the final field of view of the above size.

[0104] Furthermore, for example, the average values ​​of the number of particles with a maximum diameter of 100 μm or more and the number of particles with a maximum diameter of 300 μm or more, measured from images taken by randomly selecting 10 locations within the above-mentioned field of view, can be used. In addition, the image analysis in (2) above can be performed using the image analysis software ImageJ.

[0105] Figure 1 shows an image (240 μm × 180 μm) of a cross-section of the resin composition obtained in Example 1, taken with an electron microscope (300x magnification). The image in Figure 1 is one of four images taken from a 480 μm × 360 μm field of view, where the number of particles of each maximum diameter is counted, which was divided into four sections. Here, it can be seen that there are no particles with a maximum diameter of 300 μm or more or 100 μm or more in the image shown in Figure 1. Similarly, the number of particles with a maximum diameter of 300 μm or more and 100 μm or more are counted for the remaining three images, and the ratio of the number of particles with a maximum diameter of 300 μm or more to the number of particles with a maximum diameter of 100 μm or more is obtained from the total of the four images.

[0106] In the above method, ten randomly selected fields of view measuring 480 μm × 360 μm are divided into four sections and photographed using an electron microscope (300x magnification). The number of particles is counted in the same manner as above, and the ratio of the number of particles with a maximum diameter of 300 μm or more to the number of particles with a maximum diameter of 100 μm or more in the 480 μm × 360 μm field of view is determined. The average of these ratio values ​​from the ten locations becomes the ratio value in (2). The presence or absence of particles with a maximum diameter of 100 μm or more can also be confirmed using the same method.

[0107] Furthermore, the field of view used to count the number of particles with a maximum diameter of 100 μm or more, and the number of particles with a maximum diameter of 300 μm or more, is not limited to the aforementioned 480 μm × 360 μm, as long as it is a field of view that can count the number of particles of these sizes. The size of the field of view can be changed as appropriate.

[0108] For the photographs, the resin composition was observed at any point on a pellet of the resin composition obtained by melt-mixing, or on the fracture surface of a molded body, specifically in an area at a distance of 1 mm or more from the outermost surface to the center. The size, shape, and dispersion state of the inorganic filler particles in the resin composition are maintained even after the molded body is formed.

[0109] Component (C), by satisfying (1), can impart a flame-retardant effect to the molded product through endothermic properties that components (A) and (B) do not possess. Furthermore, by satisfying (2), component (C) can improve the mechanical strength of the molded product while keeping its effect of suppressing drip during combustion to a minimum.

[0110] The content of component (C) is 5 to 50% by mass relative to the total amount of the resin composition of the present invention. If the content of component (C) is less than 5%, the flame retardancy of the molded article will be insufficient, and if it exceeds 50% by mass, the content of polyolefin resin will be relatively low, and the characteristics of the polyolefin resin will be impaired. The content of component (C) relative to the total amount of the resin composition is preferably in the range of 10 to 30% by mass, and more preferably in the range of 15 to 25% by mass.

[0111] Component (C) contains at least an endothermic inorganic filler that satisfies the requirements of (1) (hereinafter also referred to as "endothermic inorganic filler (C1)"). Component (C) may further contain a non-endothermic inorganic filler (hereinafter also referred to as "non-endothermic inorganic filler (C2)") in which the DTA curve obtained by differential thermal analysis does not have a portion showing endothermic activity in the temperature range of 180 to 500°C, in order to set the particle size of the inorganic filler within a predetermined range.

[0112] The endothermic inorganic filler (C1) is not particularly limited as long as it consists of particles made of a material that satisfies the requirements of (1). Specifically, examples include aluminum hydroxide particles, boehmite particles, magnesium hydroxide particles, and hydromagnesite particles. These may be used individually or in combination of two or more.

[0113] Examples of non-absorptive inorganic fillers (C2) include wollastonite particles, talc particles, mica particles, glass particles, kaolin particles, magnesium sulfate particles, calcium carbonate particles, and silica particles. These may be used individually or in combination of two or more types.

[0114] In the endothermic inorganic filler (C1) and the non-endothermic inorganic filler (C2), the particle shape is not particularly limited and can be spherical, spindle-shaped, plate-shaped, flake-shaped, needle-shaped, fibrous, etc.

[0115] In the endothermic inorganic filler (C1) and the non-endothermic inorganic filler (C2), the particles may be surface-modified with a surface modifier as needed. Suitable surface modifiers include alkylsilazane compounds such as hexamethyldisilazane (HMDS), alkylalkoxysilane compounds such as dimethyldimethoxysilane, dimethyldiethoxysilane, trimethylmethoxysilane, methyltrimethoxysilane, and butyltrimethoxysilane, silicone oils, silicone varnishes, and various fatty acids. These surface modifiers may be used individually or in combination of two or more.

[0116] Furthermore, as described above, if the particles of the inorganic filler are surface-modified with organic compounds as exemplified above, an exothermic peak attributable to the organic compound may be observed in the DTA curve within the range of 180 to 500°C. In the case of particles made of various inorganic materials as exemplified in the endothermic inorganic filler (C1), even if there is an exothermic portion (exothermic peak) attributable to surface modification, for example, within the 180 to 500°C range of the DTA curve, the inorganic filler can be classified as an endothermic inorganic filler (C1) if even a small portion of it is endothermic.

[0117] The content of the endothermic inorganic filler (C1) in component (C) is preferably in the range of 10 to 100% by mass, more preferably in the range of 50 to 100% by mass, and even more preferably in the range of 80 to 100% by mass, relative to the total amount of component (C). Furthermore, the content of the endothermic inorganic filler (C1) relative to the total amount of the resin composition of the present invention is preferably 5% by mass or more. The content of the non-endothermic inorganic filler (C2) is the remainder after subtracting the content of the endothermic inorganic filler (C1) from the total amount of component (C).

[0118] The requirement in (2) for component (C) is a requirement that specifies the maximum particle size, and is a requirement for component (C) as a mixture of an endothermic inorganic filler (C1) and a non-endothermic inorganic filler (C2).

[0119] Component (C) preferably further satisfies either requirement (a) or (b) below. (a) The ratio of the number of particles with a maximum diameter of 200 μm or more to the number of particles with a maximum diameter of 100 μm or more is 1 / 10 or less, or there are no particles with a maximum diameter of 100 μm or more, The ratio of the number of particles with a maximum diameter of less than 5 μm to the number of particles with a maximum diameter of 5 μm or more is 10 or greater. (b) No particles with a maximum diameter of 5 μm or more are present.

[0120] Here, requirement (a) can be explained by dividing it into the following requirements (3) and (4). (3) The ratio of the number of particles with a maximum diameter of 200 μm or more to the number of particles with a maximum diameter of 100 μm or more is 1 / 10 or less, or there are no particles with a maximum diameter of 100 μm or more. (4) The ratio of the number of particles with a maximum diameter of less than 5 μm to the number of particles with a maximum diameter of 5 μm or more is 10 or more.

[0121] For (3) above, the same measurement method as in (2) can be applied. For (4) and (b) above, the following methods can be applied.

[0122] The number of particles with a maximum diameter of less than 5 μm and the number of particles with a maximum diameter of 5 μm or more can be counted, for example, in a field of view of a predetermined size, for example, 20 μm × 15 μm, obtained by scanning electron microscopy at a magnification of 5000x of the resin composition. A field of view of 20 μm × 15 μm is the size that can be obtained in one image when photographed at a magnification of 5000x. To obtain the ratio value in (4), 10 locations are randomly selected from the cross-section of the resin composition, and the number of particles of each maximum diameter is counted using an image (24 μm × 18 μm) at a magnification of 5000x. The average value of the 10 locations is then taken as the number of particles with a maximum diameter of less than 5 μm and the number of particles with a maximum diameter of 5 μm or more.

[0123] Figure 2 shows an image of a cross-section of the resin composition obtained in Example 1, taken with an electron microscope (5000x magnification). In this image, 141 particles with a maximum diameter of less than 5 μm are counted. In addition, 3 particles with a maximum diameter of 5 μm or more are counted. Here, for particles with a maximum diameter of 5 μm or more, in addition to particles whose entire image is captured in a 24 μm × 18 μm image, particles that are partially captured are also counted as particles with a maximum diameter of 5 μm or more. In the above method, the number of particles is counted similarly using 10 images of the same magnification, the average value is calculated, and the ratio value in (4) is calculated using that value. The presence or absence of particles with a maximum diameter of 5 μm or more in (b) can also be confirmed using the same method.

[0124] Furthermore, the field of view for counting the number of particles with a maximum diameter of less than 5 μm and the number of particles with a maximum diameter of 5 μm or more is not limited to the 24 μm × 18 μm size mentioned above, as long as the number of particles of these sizes can be counted within that field of view. The size of the field of view can be changed as appropriate.

[0125] The image analysis described in (3) and (4) above can be performed using the image analysis software ImageJ.

[0126] In requirement (2) above, the ratio value is more preferably 1 / 10 or less, and even more preferably 1 / 50 or less. Also, if there are no particles with a maximum diameter of 100 μm or more, both the numerator and denominator become "0", and the ratio value is set to "0".

[0127] In requirement (3) above, the ratio value is more preferably 1 / 50 or less, and even more preferably 1 / 80 or less. Also, if there are no particles with a maximum diameter of 100 μm or more, both the numerator and denominator become "0", and the ratio value is set to "0".

[0128] In requirement (4) above, the ratio value is more preferably 30 or greater, and even more preferably 50 or greater. Furthermore, if there are particles with a maximum diameter of less than 5 μm and no particles with a maximum diameter of 5 μm or greater, only the denominator becomes "0", so the ratio value is considered to be infinite.

[0129] By satisfying the requirements of (3) in addition to (2), rigidity can be improved by using inorganic fillers with a large maximum diameter. While inorganic fillers with a large maximum diameter may reduce flame retardancy and toughness, by satisfying (2) or (3), flame retardancy can be compensated for to a practical level by using endothermic inorganic fillers, NOR-type hindered amines, or phosphorus compounds. Furthermore, the reduction in toughness can be kept within a practical range. Moreover, by satisfying the requirements of (4), the toughness improvement effect of inorganic fillers with a small maximum diameter can be obtained, and the balance between flame retardancy, rigidity, and toughness can be improved.

[0130] Furthermore, satisfying requirement (b) yields the same effect as satisfying requirements (3) and (4) above.

[0131] (Other additives) The resin composition of the present invention may contain known additives in addition to the resin containing the polyolefin resin, component (A), component (B), and component (C) described above, as long as they do not impair the effects of the present invention. Other additives include other flame retardants, nucleating agents, dispersants, antioxidants, lubricants, compatibilizers, etc., other than components (A), (B), and (C).

[0132] <Other flame retardants> Other flame retardants include organic or inorganic flame retardants other than components (A), (B), and (C) that do not contain halogen atoms. Examples of inorganic flame retardants include silicone compounds.

[0133] <Crystallizing agent> Examples of crystal nucleating agents include sorbitols, rosins, and petroleum resins, although these are not particularly limited.

[0134] Specifically, examples include sorbitols such as alkyl-substituted benzylidene sorbitol (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, 1,3,2,4-di-(2',4'-dimethylbenzylidene) sorbitol, sodium benzoate, pt-butylbenzoate aluminum, sodium montana, calcium montana, etc. These may be used individually or in combination of two or more.

[0135] A commercially available crystal nucleating agent may be used. Examples of commercially available crystal nucleating agents include NJester NU-100 (product name, manufactured by Shin Nippon Rika Co., Ltd.).

[0136] <Antioxidant> Examples of antioxidants include hindered phenols.

[0137] <Dispersant> Examples of dispersants include fatty acids or their salts, fatty acid esters, fatty acid amides, higher alcohols, hydrogenated oils, silane coupling agents, and alcohol phosphate esters, with fatty acids or their salts being preferred. One of these dispersants may be used alone, or two or more may be used in combination. The inclusion of a dispersant improves the dispersibility of component (C) in the polyolefin resin within the resin composition. Many dispersants also function as lubricants.

[0138] As fatty acids, higher fatty acids are preferred, such as stearic acid, oleic acid, palmitic acid, linoleic acid, lauric acid, caprylic acid, behenic acid, and montanic acid. As salts of fatty acids, metal salts of the above higher fatty acids are preferred, such as stearate, oleate, palmitate, linoleate, laurate, caprylate, behenic acid, and montanate, and examples of metals include Li, Na, K, Al, Ca, Mg, Zn, and Ba.

[0139] <Lubricant> Examples of lubricants include one or more selected from the group consisting of fatty acid salts, fatty acid amides, silane polymers, solid paraffins, liquid paraffins, calcium stearate, zinc stearate, stearic acid amides, silicone powders, methylenebisstearate, and N,N'-ethylenebisstearate.

[0140] <Compatibilizer> Compatibilizers are used to adjust the interfacial strength between the polyolefin resin and component (C). Specifically, preferred compatibilizers have the same or a compatible structure as the polyolefin resin and contain a moiety within the molecule that has affinity for component (C). Examples of moieties that have affinity for component (C) include carboxyl groups, carboxylic acid anhydride residues, and carboxylic acid ester residues. From the viewpoint of the upper limit temperature during molding, it is preferable that the moiety that has affinity for component (C) includes a carboxylic acid anhydride residue. Examples of carboxylic acid anhydride residues include maleic anhydride residues and citric acid anhydride residues, with maleic anhydride residues being particularly preferred.

[0141] The compatibilizer is preferably a maleic anhydride-modified polyolefin resin. Examples of compatibilizers include SEBS (styrene-ethylene-butylene-styrene block copolymer), MAH-PP (maleic anhydride-grafted polypropylene), and CEBC (ethylene-ethylene-butylene-ethylene block copolymer).

[0142] Commercially available compatibilizers may be used. Examples of commercially available maleic anhydride modified polyolefin resins include MG-441P (product name, manufactured by Riken Vitamin Co., Ltd.) as a maleic anhydride modified polypropylene resin, and HE810 (product name, manufactured by Mitsui Chemicals, Inc.) as a maleic anhydride modified polyethylene resin. Examples of SEBS include ToughTec M1911 (product name, manufactured by Asahi Kasei Corporation).

[0143] The content of other additives in the resin composition of the present invention is within a range that does not impair the effects of the present invention, and for example, is within a range of about 0.1 to 30% by mass of the total amount of the resin composition, preferably within a range of 0.1 to 20% by mass. Furthermore, a total of 30% by mass or less is preferred.

[0144] [Method for producing resin compositions] The resin composition of the present invention can be obtained by melt-kneading the raw material components of the resin containing the polyolefin resin, component (A), component (B), component (C), and other additives that may be optionally contained, to form the resin composition of the present invention. The method of melt-kneading is not particularly limited, and known melt-kneading methods can be used.

[0145] Melt mixing is carried out using mixing equipment such as a Banbury mixer, rolls, plastograph, extruder (single-screw extruder, multi-screw extruder (e.g., twin-screw extruder), etc.), and kneader. Among these, it is preferable to use an extruder for melt mixing because it offers good production efficiency. Furthermore, it is preferable to use a multi-screw extruder for melt mixing, and more preferably a twin-screw extruder, because it can impart high shear strength. Here, the term extruder is used in a category that includes extruder mixers.

[0146] The temperature during melt mixing (melt mixing temperature) shall be equal to or higher than the melting temperature of the polyolefin resin. The melt mixing temperature is preferably, for example, 150 to 280°C and is appropriately selected depending on the polyolefin resin used. When a polypropylene resin is used as the polyolefin resin, the melt mixing temperature is preferably 170 to 250°C, and more preferably 170 to 230°C. When an extruder is used for melt mixing, the mixing melting temperature corresponds to the cylinder temperature.

[0147] When using an extruder for melt mixing, the screw rotation speed is preferably in the range of 50 to 300 rpm. Furthermore, the discharge rate of the resin composition from the extruder is preferably in the range of 1 to 50 kg / hr.

[0148] In the present invention, if necessary, components other than the resin, including polyolefin resin, may be added during the melt-mixing process, and the time required for melt-mixing may be adjusted for each component. For example, when component (C) is added during the process, the resin composition can be manufactured by using a twin-screw extruder, supplying the raw material components other than component (C) from a hopper installed at the rear of the twin-screw extruder's cylinder, and supplying component (C) from a side feeder installed at the front of the cylinder, for example, in the center. The frontmost end of the cylinder is the discharge section for the resin composition, and the rearmost end corresponds to the vicinity of the cylinder end opposite the discharge section. Component (A) or component (B) may be supplied during the process instead of component (C).

[0149] Furthermore, by adding components other than the resin, including polyolefin resin, during the melt-mixing process, for example, in the case of component (C), it is possible to suppress particle breakage and maintain the particle shape. In particular, in the case of fibrous particles, it is possible to suppress the breakage of fibrous particles and maintain a large fiber length.

[0150] Furthermore, before melting and kneading, the components may be pre-mixed (dry-blended) using various mixing machines, such as tumblers or high-speed mixers known as Henschel mixers.

[0151] In the above configuration, after the molten mixture is extruded in a strand shape from the discharge section of the extruder, the extruded strand-shaped molten mixture can be processed into pellet-like or flake-like forms.

[0152] The resin composition of the present invention can take various forms, such as powder, granules, tablets, pellets, flakes, fibers, and liquid.

[0153] <Physical properties of resin compositions> The resin composition of the present invention preferably has a portion exhibiting endothermic properties within the temperature range of 180 to 350°C in the DTA curve obtained by differential thermal analysis under a heating condition of 10°C / min. The presence of an endothermic portion is preferable because it allows for an endothermic effect by the endothermic inorganic filler (C1) that exceeds the heat generated by the thermal decomposition of the matrix polyolefin resin before or during combustion.

[0154] Figure 5 shows the DTA curve obtained by differential thermal analysis of the resin composition obtained in Example 1. Differential thermal analysis is performed using a differential thermal analyzer such as the DTG-60A (Shimadzu Corporation, simultaneous differential thermal / thermogravimetric analyzer), for example, under heating conditions of 10°C / min in an N2 gas atmosphere.

[0155] The DTA curve shown in Figure 5 exhibits endothermic peaks around 160-180°C and 295-330°C. The endothermic peak around 160-180°C is presumed to originate from the polyolefin resin of the matrix. The endothermic peak around 295-330°C is thought to be due to the endothermic inorganic filler (C1) mentioned above.

[0156] (molded product) Molded articles can be produced using the resin composition of the present invention. These molded articles provide resin products that are flame-retardant and possess excellent mechanical properties in terms of toughness and rigidity. When manufacturing molded articles, the resin composition can be melted and molded in various molding machines. The molding method can be appropriately selected depending on the form and application of the molded article, and examples include injection molding, extrusion molding, compression molding, blow molding, calendering, and inflation molding. Furthermore, sheet-like or film-like molded articles obtained by extrusion molding and calendering can be subjected to secondary molding such as vacuum forming or pressure forming.

[0157] The molded article formed from the resin composition of the present invention preferably has a flexural modulus of 1.2 GPa or higher, more preferably 1.5 GPa or higher, and even more preferably 1.8 GPa or higher, as measured in a bending test conducted in accordance with JIS-K7171 (ISO178). If the flexural modulus is 1.2 GPa or higher, the rigidity of the molded article can be evaluated as being practically acceptable.

[0158] A molded article formed from the resin composition of the present invention will, for example, have a notched Charpy impact strength of 6 kJ / m² as measured in a notched Charpy impact test conducted in accordance with JIS-K7111-1 (ISO 179-1). 2 Preferably, it is 8 kJ / m³ or higher. 2 It is more preferable that it be greater than or equal to 10 kJ / m 2 It is even more preferable that the notched Charpy impact strength is 6 kJ / m 2 Based on the above, the toughness of the molded product can be evaluated as being practically acceptable.

[0159] A molded article formed from the resin composition of the present invention will, for example, have a notched Charpy impact strength of 60 kJ / m² as measured in a notched Charpy impact test conducted in accordance with JIS-K7111-1 (ISO 179-1). 2 Preferably, it is 80 kJ / m³ or more. 2 It is more preferable that it be greater than or equal to 90kJ / m³ 2 It is even more preferable that the material is above or does not break (hereinafter also referred to as "NB"). The notched Charpy impact strength is 60 kJ / m 2 Based on the above, the toughness of the molded product can be evaluated as being practically acceptable.

[0160] The flame retardancy of molded articles formed from the resin composition of the present invention can be evaluated using, for example, the following indicators. Here, "flame retardancy" refers to resistance to fire caused by external sources. While there are various standards for evaluating flame retardancy, such as JIS and ASTM, the UL standard is generally considered particularly important. The UL standard is established and evaluated by the American company Underwriters Laboratories.

[0161] In molded articles formed from the resin composition of the present invention, when a test piece of a predetermined size is evaluated according to the above UL standard, it is preferable that the combustion test in accordance with the UL94V test is judged to be V-2 or higher, more preferably V-1 or higher, and even more preferably V-0.

[0162] Alternatively, the average burn time in the UL94V test may be used as an indicator. The average burn time can be measured by the following method. When a test is performed on a molded article formed from the resin composition of the present invention using a test piece of a predetermined size, the average burn time is preferably less than 30 seconds, more preferably 20 seconds or less, and even more preferably 10 seconds or less.

[0163] [Method for measuring average burning time] In the UL94V test (vertical combustion test), the lower end of the test specimen is exposed to a flame for 10 seconds, and the time until the flame extinguishes (burning time) is measured. The same test is repeated twice on the same test specimen, with the burning time during the first exposure being designated as T1 and the burning time during the second exposure as T2. The average value (T1 + T2) / 2 is calculated and used as the burning time for the test specimen. Five test specimens are prepared, and the same test is performed on all five specimens. The average burning time of the five test specimens is used as the average burning time.

[0164] The molded articles formed from the resin composition of the present invention are not particularly limited and include, for example, electrical and electronic components, electrical components, exterior parts, and interior parts in fields such as information equipment, home appliances, and automobiles, as well as various packaging materials, household goods, office supplies, piping, and agricultural materials. [Examples]

[0165] The present invention will be described in detail below with reference to examples, but the present invention is not limited to these examples. In the examples, the units "parts" or "%" are used, and unless otherwise specified, they refer to "parts by mass" or "mass%".

[0166] [Resin compositions; Examples 1-18, Comparative Examples 1-6] The following commercially available products were prepared as raw material components to be included in the resin compositions of each example and comparative example.

[0167] <Resin> • Polypropylene resin: Prime PolyPro J715M (product name, manufactured by Prime Polymer Co., Ltd.) • Polyethylene resin: HJ560 (product name, manufactured by Nippon Polyethylene Co., Ltd.)

[0168] <Ingredient (A)> • Phosphate ester compound 1: PX-200 (product name, manufactured by Daihachi Chemical Industry Co., Ltd., resorcinol bis-dixylenyl phosphate) • Phosphate ester compound 2: CR-741 (product name, manufactured by Daihachi Chemical Industry Co., Ltd., bisphenol A bis(diphenyl phosphate))

[0169] <Ingredient (B)> • NOR-type hindered amine 1: Flamestab NOR116FF (product name, manufactured by BASF, N,N',N'''-tris{2,4-bis[(1-cyclohexyloxy-2,2,6,6-tetramethylpiperidine-4-yl)n-butylamino]-s-triazine-6-yl}-3,3'-ethylenediiminodipropylamine) • NOR-type hindered amine 2: TINUVIN NOR371FF (product name, manufactured by BASF, 1,6-Hexanediamine, N1,N6-bis(2,2,6,6-tetramethyl-4-piperidinyl)-, polymer with 2,4,6-trichloro-1,3,5-triazine, reaction products with 3-bromo-1-propene, N-butyl-1-butanamine and N-butyl-2,2,6,6-tetramethyl-4-piperidinamine, oxidized, hydrogenated)

[0170] <Ingredient (C)> <Component (C1): Endothermic inorganic filler> • Aluminum hydroxide particles: KH-101 (product name, manufactured by KC Corporation, particles with an average primary particle size of 1.0 μm). Figure 3 shows the DTA curve for KH-101 measured by differential thermal analysis (DTG-60A, manufactured by Shimadzu Corporation, under N2 gas atmosphere, heating conditions: 10°C / min). • Magnesium hydroxide particles: Magsies N-6 (product name, manufactured by Kamishima Chemical Industry Co., Ltd., average primary particle size of 1.2 μm, surface-modified with higher fatty acids)

[0171] Furthermore, it has been confirmed that each of the inorganic fillers listed above as component (C1) has a portion of the DTA curve obtained by differential thermal analysis that shows endothermic activity in the temperature range of 180 to 500°C, similar to the example shown in Figure 3.

[0172] <Component (C2); Non-absorbent inorganic filler> • Wollastonite particles 1: NYGLOS8 (product name, manufactured by IMERYS, average primary particle size; fiber length 156 μm × fiber diameter 12 μm), • Wollastonite particles 2: NYGLOS4W (product name, manufactured by IMERYS, average primary particle size; fiber length 63 μm × fiber diameter 7 μm) • Calcium carbonate particles: Calciz P (product name, manufactured by Kamishima Chemical Industry Co., Ltd., average primary particle size: 0.2 μm, surface modified with fatty acids) Figure 4 shows the DTA curve for Calciz P measured by differential thermal analysis (DTG-60A, manufactured by Shimadzu Corporation, under N2 gas atmosphere, heating conditions: 10°C / min). • Mica particles: Suzorite 350-P0 (product name, manufactured by IMERYS, average primary particle size; median diameter 25 μm) • Talc particles: Microace P3-RC (product name, manufactured by Nippon Talc Co., Ltd., average primary particle size; median diameter 5.0 μm) • Kaolin particles: Hydrite SB100 (product name, manufactured by IMERYS, average primary particle size: 1.2 μm) • Glass particles (fibrous particles): CSF 3PE-957 (product name, manufactured by Nitto Boseki Co., Ltd., average primary particle size; fiber length 3000 μm × fiber diameter 13 μm)

[0173] Furthermore, it has been confirmed that each of the inorganic fillers listed above as component (C2) does not have a portion of the DTA curve obtained by differential thermal analysis that shows endothermic activity in the temperature range of 180 to 500°C, for example, as shown in Figure 4.

[0174] As for component (C), the DTA curve obtained by differential thermal analysis will have an endothermic portion in the temperature range of 180 to 500°C if component (C) contains component (C1).

[0175] <Other ingredients> • Magnesium stearate: Daiwax M (product name, manufactured by Dainichi Chemical Industry Co., Ltd.) • Nucleating agent: NJester NU-100 (product name, manufactured by Shin Nippon Rika Co., Ltd.) • SEBS: ToughTec M1911 (product name, manufactured by Asahi Kasei Corporation)

[0176] (Manufacturing of resin compositions) In each example and comparative example, each component was used in the amounts (mass%) shown in Tables I, II, and III. In the composition section of Tables I, II, and III, a blank space indicates that the content of that component is "0".

[0177] A twin-screw extruder (HYPERKTX-30, manufactured by Kobe Steel, Ltd.) was used for melting and mixing at a maximum cylinder temperature of 180°C, a die temperature of 170°C, and a screw rotation speed of 150 rpm. The discharge rate was 10 kg / hr.

[0178] For Examples 9, 10, 12 and Comparative Example 3, the raw material components other than the side-feed components were pre-dry-blended and then supplied from a hopper installed at the rear of the twin-screw extruder cylinder, while the side-feed components were supplied from a side feeder installed in the center of the cylinder. For the other examples and comparative examples, all raw material components were pre-dry-blended and then supplied from a hopper installed at the rear of the twin-screw extruder cylinder.

[0179] The side-feed components in Examples 9, 10, 12 and Comparative Example 3 were wollastonite particles 1, glass particles (fibrous particles), phosphate ester 2, and glass particles (fibrous particles), respectively.

[0180] The strands extruded from the extruder were cut by a pelletizer and processed into pellets approximately 3 mm in diameter and 5 mm in length to obtain the resin composition.

[0181] [Physical properties of resin compositions] The resin compositions of Examples 1 to 18 and Comparative Examples 1 to 6 obtained above underwent the following physical property measurements (i) to (iv). The results are shown in Tables I, II, and III.

[0182] (i) Relationship of the maximum particle size of component (C) For each resin composition pellet obtained above, we observed the region located at a distance of 1 mm or more from the outermost surface to the center.

[0183] The number of particles with a maximum diameter of 100 μm or more, the number of particles with a maximum diameter of 200 μm or more, and the number of particles with a maximum diameter of 300 μm or more were counted in a 480 μm × 360 μm field of view area, obtained by imaging the resin composition at 300x magnification using a scanning electron microscope: JSM-7401F (manufactured by JEOL Ltd.). The 480 μm × 360 μm field of view area is four times the size (twice the vertical and horizontal dimensions) of the image obtainable in one image (240 μm × 180 μm) when imaging at 300x magnification. The field of view area was divided into four images (2 vertical × 2 horizontal = 4 images), and the number of particles of each maximum diameter was counted in the final field of view area of ​​the above size.

[0184] Figure 1 shows an image (240 μm × 180 μm) of a cross-section of the resin composition obtained in Example 1, taken with an electron microscope (300x magnification). The image in Figure 1 is one of four images taken from a 480 μm × 360 μm field of view, where the number of particles of each maximum diameter is counted, divided into four sections. Here, it can be seen that there are no particles with a maximum diameter of 300 μm or more or 100 μm or more in the image shown in Figure 1. Similarly, the number of particles with a maximum diameter of 300 μm or more and 100 μm or more were counted for the remaining three images, and the ratio of the number of particles with a maximum diameter of 300 μm or more to the number of particles with a maximum diameter of 100 μm or more was obtained from the total of the four images. The ratio of the number of particles with a maximum diameter of 200 μm or more to the number of particles with a maximum diameter of 100 μm or more was also obtained.

[0185] Using images taken from 10 randomly selected fields of view of the above size, the ratio of the number of particles with a maximum diameter of 300 μm or more to the number of particles with a maximum diameter of 100 μm or more, and the ratio of the number of particles with a maximum diameter of 200 μm or more to the number of particles with a maximum diameter of 100 μm or more were obtained at each measurement site. These were averaged to calculate the ratio values ​​related to requirement (2) and requirement (3).

[0186] The number of particles with a maximum diameter of less than 5 μm and the number of particles with a maximum diameter of 5 μm or more were counted using a scanning electron microscope: JSM-7401F (manufactured by JEOL Ltd.) at a magnification of 5000x (field of view of 24 μm × 18 μm) at 10 randomly selected locations. Figure 2 shows one image of a cross-section of the resin composition obtained in Example 1, taken with an electron microscope (5000x).

[0187] Ten randomly selected locations within the field of view of the above size were captured, and the number of particles with a maximum diameter of less than 5 μm and the number of particles with a maximum diameter of 5 μm or more were measured from the images. At each measurement location, the ratio of the number of particles with a maximum diameter of less than 5 μm to the number of particles with a maximum diameter of 5 μm or more was obtained. These were averaged to calculate the ratio value related to the requirement of (4).

[0188] (2) The ratio value related to the requirement of (2); the ratio of the number of particles with a maximum diameter of 300 μm or more to the number of particles with a maximum diameter of 100 μm or more (indicated as "300 μm or more / 100 μm or more" in the table). (3) The ratio value related to requirement (3); the ratio of the number of particles with a maximum diameter of 200 μm or more to the number of particles with a maximum diameter of 100 μm or more (indicated as "200 μm or more / 100 μm or more" in the table). (4) The ratio value related to requirement (4); the ratio of the number of particles with a maximum diameter of less than 5 μm to the number of particles with a maximum diameter of 5 μm or more (indicated as "less than 5 μm / 5 μm or more" in the table).

[0189] (ii) Measurement of phosphorus concentration (mass%) The phosphorus content was measured using pellets of each resin composition obtained above. The phosphorus content (mass%) was measured using an energy-dispersive X-ray fluorescence spectrometer (JEOL JSX-1000S).

[0190] (iii) DTA measurement Using pellets of each resin composition obtained above, differential thermal analysis (DTG-60A, Shimadzu Corporation, under N2 gas atmosphere, heating condition: 10°C / min) was performed to obtain DTA curves. The presence or absence of an endothermic portion within the temperature range of 180 to 350°C was checked for the DTA curves. The results for Example 1 are shown in Figure 5. The table also indicates the presence or absence of an endothermic portion within the temperature range of 180 to 350°C in the DTA curves for each example and comparative example.

[0191] Although the resin compositions obtained in Examples 6 and 10 contain an endothermic inorganic filler (C1), these resin compositions do not have an endothermic portion in the temperature range of 180 to 350°C of the DTA curve. This is thought to be due to the influence of components other than the endothermic inorganic filler (C1).

[0192] (iv) Measurement of halogen content Using pellets of each resin composition obtained above, the halogen element content in the resin composition was measured by flask combustion ion chromatography. The results showed that in all resin compositions, the chlorine content was 900 ppm by mass or less, the bromine content was 900 ppm by mass or less, and the total content of chlorine and bromine was 1500 ppm by mass or less.

[0193] <Rating> The resin compositions of Examples 1 to 18 and Comparative Examples 1 to 6 obtained above were evaluated for their mechanical strength (flexural modulus and impact strength) and flame retardancy. The results are shown in Tables I, II, and III. Note that Example 8 is for reference only.

[0194] (Conditions for manufacturing test specimens) After drying the resin composition pellets of each example and comparative example at 80°C for 4 hours, evaluation molded products were produced using an injection molding machine (Roboshot S-2000i 50Bp, manufactured by Fanuc). The maximum cylinder temperature during molding was 200°C, and the mold temperature was 80°C.

[0195] (1) Measurement of the flexural modulus Under the molding conditions described above, rectangular test specimens measuring 80 mm x 10 mm x 4 mm were molded, and bending tests were conducted in accordance with JIS-K7171 (ISO178). The flexural modulus [GPa] was measured and evaluated according to the following criteria. A flexural modulus of 1.2 GPa or higher was considered sufficient for practical use, indicating that the strength of the molded product was acceptable.

[0196] (Evaluation Criteria) ◎: 1.8 GPa or higher ○: 1.5 GPa or higher, less than 1.8 GPa △: 1.2 GPa or higher, less than 1.5 GPa ×: Less than 1.2 GPa

[0197] (2-1) Measurement of Charpy impact strength with notch Under the molding conditions described above, 80mm x 10mm x 4mm strip-shaped test specimens (with notches) were prepared in accordance with JIS-K7111-1 (ISO 179-1), and a notched Charpy impact test was performed. Notched Charpy impact strength [kJ / m 2 The following criteria were used to measure and evaluate the Charpy impact strength with a notch: 6 kJ / m². 2 Based on the above, we determined that the toughness of the molded product is not a practical problem.

[0198] (Evaluation Criteria) ◎: 10kJ / m 2 That's all. ○: 8kJ / m 2 More than 10kJ / m 2 less than △: 6kJ / m 2 More than 8kJ / m 2 less than ×: 6kJ / m 2 less than

[0199] (2-2) Measurement of Charpy impact strength without notches Under the molding conditions described above, a strip-shaped test specimen (without notches) measuring 80 mm × 10 mm × 4 mm was prepared in accordance with JIS-K7111-1 (ISO 179-1), and a Charpy impact test without notches was performed. Charpy impact strength without notches [kJ / m 2 The following criteria were used to measure and evaluate the Charpy impact strength without notches: 60 kJ / m². 2 Based on the above, we determined that the toughness of the molded product is not a practical problem.

[0200] (Evaluation Criteria) ◎: 90kJ / m 2 Above or NB (Not Broken) ○: 80kJ / m 2 More than 90kJ / m 2 less than △: 60kJ / m 2 More than 80kJ / m 2 less than ×: 60kJ / m 2 less than

[0201] (3-1) Combustion test (flame retardancy evaluation) Under the molding conditions described above, five rectangular test specimens measuring 125 mm x 12.5 mm x 1.6 mm were prepared and subjected to combustion tests in accordance with UL94V, and evaluated according to the following criteria. Specimens that received a combustion test rating of V-2 or higher were deemed to be practically acceptable.

[0202] (Evaluation Criteria) ◎: Cases where the result was V-0, V-1, or V-2. ×: The result was not V (it did not meet the V-2 requirement).

[0203] (3-2) Combustion test (average burning time) In the UL94V-compliant vertical combustion test described above, the lower end of the test specimen was exposed to a flame for 10 seconds, and the time until extinguishing (burning time) was measured. The same test specimen was repeated twice, with the burning time during the first exposure being designated as T1 and the burning time during the second exposure as T2. The average value (T1 + T2) / 2 was calculated and used as the burning time for the test specimen. The same test was performed on five test specimens, and the average burning time of the five test specimens was taken as the average burning time (sec), which was evaluated according to the following criteria. It was determined that an average burning time of less than 30 seconds was acceptable for practical use.

[0204] (Evaluation Criteria) ◎: 10 seconds or less 〇: More than 10 seconds, less than 20 seconds △: Over 20 seconds, under 30 seconds ×: 30 seconds or more, or burn out

[0205] [Table 1]

[0206] [Table 2]

[0207] [Table 3]

[0208] Tables I, II, and III show that using the resin composition of the present invention, molded articles with excellent mechanical strength and flame retardancy can be produced economically with stable quality.

Claims

1. A halogen-free resin composition containing a polyolefin resin, The inorganic filler includes an endothermic inorganic filler and a non-endothermic inorganic filler. The aforementioned endothermic inorganic filler has a portion of the DTA curve obtained by differential thermal analysis that shows endothermic activity in the temperature range of 180 to 500°C. The non-endothermic inorganic filler does not have a portion of the DTA curve obtained by differential thermal analysis that shows endothermic activity in the temperature range of 180 to 500°C. The aforementioned endothermic inorganic filler is at least one selected from aluminum hydroxide particles and magnesium hydroxide particles. The non-heat-absorbing inorganic filler is at least one selected from wollastonite particles, calcium carbonate particles, mica particles, talc particles, kaolin particles, and glass particles. With respect to the total amount of the aforementioned resin composition, The phosphorus compound is present in a phosphorus content of 0.05 to 2.5% by mass. NOR-type hindered amine in an amount of 0.05 to 5% by mass, and Each of the inorganic fillers contains 15 to 50% by mass, Of the inorganic fillers, the endothermic inorganic filler is contained in an amount of 5 to 25% by mass relative to the total amount of the resin composition, The resin composition is characterized in that, in the inorganic filler, the ratio of the number of particles with a maximum diameter of 300 μm or more to the number of particles with a maximum diameter of 100 μm or more is 1 / 5 or less, or no particles with a maximum diameter of 100 μm or more are present.

2. The resin composition according to claim 1, characterized in that the polyolefin resin is a polypropylene-based resin.

3. The resin composition according to claim 1 or 2, characterized in that the phosphorus compound includes a phosphate ester compound.

4. In the DTA curve obtained by differential thermal analysis under a heating condition of 10°C / min, The resin composition according to any one of claims 1 to 3, characterized in that it has a portion that exhibits heat absorption within a temperature range of 180 to 350°C.

5. With respect to the total amount of the aforementioned resin composition, The phosphorus compound is present in an amount of 0.1 to 1.5% by mass as a phosphorus content. The aforementioned NOR-type hindered amine is present in an amount of 0.1 to 2% by mass. Each of the inorganic fillers contains 15 to 30% by mass, and The resin composition according to any one of claims 1 to 4, characterized in that the inorganic filler satisfies either (a) or (b) below. (a) The ratio of the number of particles with a maximum diameter of 200 μm or more to the number of particles with a maximum diameter of 100 μm or more is 1 / 10 or less, or there are no particles with a maximum diameter of 100 μm or more, The ratio of the number of particles with a maximum diameter of less than 5 μm to the number of particles with a maximum diameter of 5 μm or more is 10 or more. (b) No particles with a maximum diameter of 5 μm or more are present.

6. Furthermore, the resin composition according to any one of claims 1 to 5, characterized in that it contains a fatty acid or a salt thereof.

7. A method for producing a resin composition according to any one of claims 1 to 6, A method for producing a resin composition, characterized by comprising the step of kneading raw material components, including the polyolefin resin, the phosphorus compound, the NOR-type hindered amine, and the inorganic filler, using a twin-screw extruder.

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