Resin composition and method for producing same

Abstract

To provide a resin composition for injection molding which enables economical production of an injection molding having excellent mechanical strength, flame retardancy and appearance with stable quality, and a method for producing the same.SOLUTION: A resin composition is a resin composition for injection molding containing a polyolefin resin, contains 10-60 mass% of at least one selected from aluminum hydroxide, magnesium hydroxide and a phosphorus compound, 0.05-5 mass% of an NOR type hindered amine compound, and 1-20 mass% of a fibrous filler having an aspect ratio of 10 or more, with respect to the total amount of the resin composition, and has a phosphorus content of 5 mass% or less with respect to the total amount of the resin composition.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a resin composition and a method for producing the same. More particularly, the present invention relates to a resin composition for injection molding that can economically produce injection-molded articles with stable quality and excellent mechanical strength, flame retardancy, and appearance, and to a method for producing the same. [Background technology]

[0002] Polyolefin resins, such as polypropylene, are used in a variety of applications due to their light weight, excellent chemical resistance, high elongation, and low cost. Because polyolefin resins are flammable, molding resin compositions containing a large amount of flame retardant added to the resin are used when flame retardancy is required for molded products. However, the addition of flame retardants can sometimes impair the above-mentioned characteristics of polyolefin resins. Conventionally, various flame retardants, such as halogen-based compounds, phosphorus-based compounds, and metal hydrates, have been known. It is also known to add fillers, such as glass fibers, to polyolefin resins to improve the strength of molded products.

[0003] As a technique for improving both flame retardancy and strength, Patent Document 1 describes a long glass fiber-containing resin composition in which a flame retardant containing ammonium polyphosphate and a nitrogen compound, and long glass fibers are added to a polyolefin resin, resulting in an excellent balance between rigidity and impact resistance, good flame retardancy, elongation properties, and dimensional stability, and an anti-drip effect during combustion.

[0004] Patent Document 2 describes a method for obtaining a molded article by dry-blending pellets of long glass fibers impregnated with polyolefin resin and pellets of a composition of polyolefin resin and a specific phosphate, and directly molding the mixture as a long glass fiber-containing flame-retardant resin composition. Patent Document 2 also describes that when polyolefin resin-impregnated long glass fiber pellets of 2 to 50 mm in length are used, the average length of the glass fibers in the molded article is 1 to 6 mm, and that glass fibers of this length improve the oxygen index.

[0005] However, these techniques have posed a problem of mold wear during injection molding because polyolefin resin compositions contain fillers such as glass fibers, which have a relatively high hardness. This problem is particularly pronounced at the gate of the mold, where the resin composition flows at high shear rates and pressures. Furthermore, flame retardants that generate acidic gases, such as those containing phosphorus-based compounds, promote mold wear due to corrosion, and when flame retardants such as metal hydroxides are used, the amount of high-hardness fillers increases, which leads to the problem of accelerated mold wear. Mold wear ultimately leads to reduced yields of molded products and increased production costs due to mold replacement, which are problematic.

[0006] Furthermore, hindered amine light stabilizers are used in various fields as light resistance stabilizers that prevent deterioration due to light, and it is known that NOR-type hindered amine compounds (hereinafter sometimes referred to as "NOR-type HALS") act as flame retardants and can efficiently improve flame retardancy (see, for example, Patent Documents 3 and 4). These patent documents show that the flame retardancy and weather resistance of films, sheets, and fibers are improved, but do not mention other effects, such as the effect of suppressing wear and corrosion of molds during injection molding. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Japanese Patent Application Publication No. 10-338774 [Patent Document 2] Japanese Patent Application Laid-Open No. 2011-88970 [Patent Document 3] Special Publication No. 2002-507238 [Patent Document 4] Japanese Patent Application Laid-Open No. 2015-189785 Summary of the Invention [Problem to be solved by the invention]

[0008] The present invention has been made in view of the above problems and circumstances, and an object of the present invention is to provide a resin composition for injection molding that can economically produce injection-molded articles having excellent mechanical strength, flame retardancy, and appearance with stable quality, and a method for producing the same. [Means for solving the problem]

[0009] In the course of investigating the causes of the above problems in order to solve the above problems, the present inventors discovered that a resin composition for injection molding containing a polyolefin resin can be provided that allows for the economical production of injection-molded articles with excellent mechanical strength, flame retardancy, and appearance with stable quality, by incorporating at least one compound selected from aluminum hydroxide, magnesium hydroxide, and a phosphorus compound, a NOR-type hindered amine compound, and a fibrous filler having an aspect ratio of 10 or more, each in specific proportions, and by controlling the phosphorus content in the resin composition to a specific amount or less. This discovery led to the present invention. That is, the above-mentioned problems of the present invention are solved by the following means.

[0010] 1. A resin composition for injection molding containing a polyolefin resin, Relative to the total amount of the resin composition 10 to 60 mass% of at least one selected from aluminum hydroxide, magnesium hydroxide, and phosphorus compounds, 0.05 to 5% by mass of a NOR type hindered amine compound, and Aspect ratio of 10 or more , 60 or less, and the average fiber length is 0.01 to 1 mm Each of the fibrous fillers is contained in an amount of 1 to 20 mass %, The phosphorus content of the resin composition is 5% by mass or less relative to the total amount of the resin composition. the law of nature, The fibrous filler is At least one of glass fiber, wollastonite, potassium titanate, and halloysite A resin composition comprising:

[0011] 2. The resin composition according to item 1, wherein the polyolefin resin is a polypropylene-based resin.

[0012] 3. The resin composition according to item 1 or 2, wherein the phosphorus compound includes a phosphoric acid ester compound.

[0013] 4. A resin composition described in any one of items 1 to 3, characterized in that the mass ratio of the total content of the aluminum hydroxide and the magnesium hydroxide to the content of the phosphorus compound is within the range of 100:0 to 75:25.

[0014] 5. The aspect ratio of the fibrous filler is 50 or more. , 60 or less 5. The resin composition according to any one of items 1 to 4, wherein

[0015] 6. A resin composition according to any one of items 1 to 5, characterized in that the fibrous filler contains halloysite.

[0016] 7. A method for producing the resin composition according to any one of items 1 to 6, comprising the steps of: a first step of melt-kneading the polyolefin resin, at least one compound selected from the group consisting of aluminum hydroxide, magnesium hydroxide, and a phosphorus compound, and the NOR-type hindered amine compound to obtain a resin mixture; and a second step of melt-kneading the resin mixture and the polyolefin resin having an aspect ratio of 10 or more. , 60 or less, and the average fiber length is 0.01 to 1 mm A second step of melt-kneading the raw material components of the fibrous filler; The fibrous filler is at least one of glass fiber, wollastonite, potassium titanate, and halloysite. A method for producing a resin composition, comprising: [Effects of the Invention]

[0017] According to the above-mentioned means of the present invention, it is possible to provide a resin composition for injection molding that can economically produce injection-molded articles of stable quality that are excellent in mechanical strength, flame retardancy and appearance, and a method for producing the same. The mechanism by which the effects of the present invention are manifested or the mechanism of action is presumed as follows.

[0018] The present inventors considered that in order to obtain mechanical strength in injection-molded articles, it was necessary to incorporate a specific amount of fibrous filler with an aspect ratio of 10 or more into a resin composition containing a polyolefin resin. However, when fibrous filler with an aspect ratio of 10 or more passes through the gate of a mold at high speed and pressure during injection molding, mold wear occurs. In the present invention, by blending a specific amount of NOR-type HALS, the melt viscosity of the resin composition at this time is reduced, thereby suppressing mold wear.

[0019] It is generally known that NOR-type HALS has a radical trapping effect (for example, Patent Document 3). JP-A-2004-263033 also discloses that NOR-type HALS has a drip-promoting effect. The drip-promoting effect of NOR-type HALS is presumed to reflect the phenomenon in which melt viscosity drops suddenly when the temperature rises suddenly due to combustion.

[0020] When a resin composition containing the above-mentioned fibrous filler is injection molded, shear heat is generated at the gate where the resin composition flows at high pressure and speed, and it is assumed that NOR-type HALS has the effect of reducing the melt viscosity at this time.In this way, it is believed that by blending a specific amount of NOR-type HALS into a resin composition containing the above-mentioned fibrous filler, it is possible to suppress mold wear.

[0021] The resin composition of the present invention further contains a specific amount of at least one flame retardant selected from aluminum hydroxide, magnesium hydroxide, and a phosphorus compound, provided that the phosphorus content is 5% by mass or less, thereby imparting flame retardancy while maintaining the effect of suppressing mold wear. Here, NOR-type HALS also functions as a flame retardant, but in the present invention, the combination of at least one selected from aluminum hydroxide, magnesium hydroxide, and a phosphorus compound ensures sufficient flame retardancy in the molded product.

[0022] Although there are concerns that aluminum hydroxide, magnesium hydroxide, and phosphorus compounds may also promote mold wear as described above, their content can be reduced by combining them with NOR-type HALS. Furthermore, by using the resin composition of the present invention in injection molding, the load on the equipment during injection molding, such as mold wear, is reduced, thereby improving the yield of molded products and reducing the production costs associated with replacing molds, etc.

[0023] As described above, the resin composition of the present invention, when configured as described above, allows for the economical production of injection-molded articles of stable quality that are excellent in mechanical strength, flame retardancy, and appearance. DETAILED DESCRIPTION OF THE INVENTION

[0024] The resin composition of the present invention is a resin composition for injection molding containing a polyolefin resin, characterized in that it contains, relative to the total amount of the resin composition, 10 to 60 mass% of at least one selected from aluminum hydroxide, magnesium hydroxide, and a phosphorus compound, 0.05 to 5 mass% of a NOR-type hindered amine compound, and 1 to 20 mass% of a fibrous filler having an aspect ratio of 10 or more, and that the phosphorus content relative to the total amount of the resin composition is 5 mass% or less. This feature is a technical feature common to each of the following embodiments.

[0025] In one embodiment of the resin composition of the present invention, the polyolefin resin is a polypropylene-based resin, which is preferable since the effects of the present invention are more significantly exhibited.

[0026] In an embodiment of the resin composition of the present invention, from the viewpoint of exhibiting the effects of the present invention, the phosphorus compound preferably includes a phosphate ester compound.

[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 mass ratio of the total content of the aluminum hydroxide and the magnesium hydroxide to the content of the phosphorus compound is within the range of 100:0 to 75:25.

[0028] In an embodiment of the resin composition of the present invention, the aspect ratio of the fibrous filler is preferably 50 or more, from the viewpoint of exerting the effects of the present invention.

[0029] In an embodiment of the resin composition of the present invention, from the viewpoint of exerting the effects of the present invention, the fibrous filler preferably contains halloysite.

[0030] The method for producing a resin composition of the present invention is a method for producing a resin composition of the present invention, and is characterized by comprising: a first step of melt-kneading the polyolefin resin, at least one compound selected from the group consisting of aluminum hydroxide, magnesium hydroxide, and a phosphorus compound, and the NOR-type hindered amine compound to obtain a resin mixture; and a second step of melt-kneading the resin mixture and raw material components of the fibrous filler having an aspect ratio of 10 or more.

[0031] By using the above manufacturing method, even when a material that is prone to changes in aspect ratio due to cutting or the like when melt-kneaded is used as a raw material component of a fibrous filler having an aspect ratio of 10 or more, an aspect ratio of 10 or more can be achieved in the resulting resin composition.

[0032] The present invention, its components, and embodiments for carrying out the present invention will be described in detail below. In this application, the symbol "to" is used to mean that the numerical values ​​before and after it are included as lower and upper limits.

[0033] [Resin composition] The resin composition of the present invention is a resin composition for injection molding containing a polyolefin resin, and is characterized in that it contains, relative to the total amount of the resin composition, 10 to 60 mass% of at least one compound selected from aluminum hydroxide, magnesium hydroxide, and a phosphorus compound (hereinafter also referred to as component (A)), 0.05 to 5 mass% of a NOR-type hindered amine compound (hereinafter also referred to as component (B)), and 1 to 20 mass% of a fibrous filler having an aspect ratio of 10 or more (hereinafter also referred to as component (C)), and that the phosphorus content relative to the total amount of the resin composition is 5 mass% or less.

[0034] The resin composition of the present invention may optionally contain, in addition to the above-mentioned components, other resins other than polyolefin resins and various additives generally contained in resin compositions, within the scope of not impairing the effects of the present invention. Each component in the resin composition of the present invention will be described below.

[0035] (Polyolefin resin) Polyolefin resins are homopolymers or copolymers polymerized using olefins as the main monomer component. In this specification, "olefin" refers to an aliphatic chain unsaturated hydrocarbon having one double bond.

[0036] Here, the main component constituting the resin (polymer) refers to a component that accounts for 50% by mass or more of all the monomer components constituting the polymer. Polyolefin-based resins are homopolymers or copolymers containing olefins in an amount of preferably 60 to 100% by mass, more preferably 70 to 100% by mass, and even more preferably 80 to 100% by mass of all the monomer components.

[0037] The olefin copolymer includes a copolymer of an olefin with another olefin, or a copolymer of an olefin with another monomer copolymerizable with the olefin. The content of the other monomer in the polyolefin resin is preferably 30% by mass or less, more preferably 0 to 20% by mass, of the total monomer components.

[0038] The olefin is preferably an α-olefin having 2 to 12 carbon atoms. Examples of the olefin include ethylene, propylene, 1-butene, isobutene, 1-pentene, 3-methyl-1-butene, 1-hexene, 1-octene, and 1-decene. When polymerizing the polyolefin resin, one type of olefin may be used alone, or two or more types may be used in combination.

[0039] Examples of other monomers copolymerizable with olefins 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 ether, maleic anhydride, carbon monoxide, and N-vinylcarbazole may also be used. When polymerizing polyolefin-based resins, the above-mentioned other monomers may be used alone or in combination of two or more. Note that "(meth)acrylic acid" refers to at least one of acrylic acid and methacrylic acid.

[0040] Specific examples of polyolefin-based resins include polyethylene resins whose main component is ethylene, such as high-density polyethylene (HDPE), low-density polyethylene (LDPE), and linear low-density polyethylene (LLDPE); polypropylene-based resins whose main component is propylene, such as polypropylene (propylene homopolymer), ethylene-propylene copolymer, propylene-butene copolymer, ethylene-propylene-butene copolymer, and ethylene-propylene-diene copolymer; polybutene; and polypentene.

[0041] Specific examples of polyolefin resins include ethylene-vinyl acetate copolymer (EVA), ethylene-ethyl acrylate copolymer, polyketone, and copolymers produced with metallocene catalysts. Also included are chemically modified versions of these polymers, such as ionomer resins, saponified EVA, and olefin elastomers produced by dynamic vulcanization in an extruder.

[0042] As the polyolefin-based resin, polyethylene-based resin and polypropylene-based resin are preferred, and polypropylene-based resin is more preferred. The stereoregularity of the propylene-derived structure in the polypropylene-based resin may be any of isotactic, syndiotactic, and atactic. As the polypropylene-based resin, polypropylene is more preferred.

[0043] The polyolefin resin contained in the resin composition of the present invention may be one type or two or more types. Commercially available polyolefin resins may be used.

[0044] The content of the polyolefin resin in the resin composition of the present invention is the amount obtained by subtracting the contents of the above-mentioned components (A), (B), and (C) from the total amount of the resin composition, and any other components that may be optionally contained. The content of the polyolefin resin relative to the total amount of the resin composition can be, for example, in the range of 20 to 90 mass%, and more preferably in the range of 30 to 80 mass%.

[0045] (Other resins) The resin composition of the present invention may contain other resins besides polyolefin-based resins. The other resins may be, for example, thermoplastic resins, specifically, polyester resins such as polystyrene resin, acrylonitrile-butadiene-styrene copolymer (ABS resin), polycarbonate resin, and polyethylene terephthalate. These may be used alone or in combination of two or more. Commercially available products may be used as the other resins.

[0046] Furthermore, as the other resin, a resin that functions as a toughener may be used. A toughener is, for example, a resin having rubber elasticity, used for the purpose of improving the flexibility, processability, impact resistance, etc. of a resin composition. As described above, when a toughener is added, it is expected that the rigidity will decrease as a side effect. Therefore, when using a toughener, the content should be adjusted carefully so as not to impair the effects of the present invention.

[0047] The resin used as a toughener is preferably a thermoplastic elastomer containing a soft segment formed from a polymer of a monomer containing butadiene and a hard segment formed from a polymer of a monomer having an aromatic group, such as styrene. Examples of such thermoplastic elastomers include methyl methacrylate-butadiene-styrene copolymer (MBS), acrylonitrile-butadiene-styrene copolymer (ABS), styrene-butadiene-styrene copolymer (SBS), and butyl acrylate-methyl methacrylate copolymer. Among these, it is preferable that the toughener be one or more selected from the group consisting of MBS and ABS, from the viewpoints of the compatibility and flame retardancy of the resin composition and the dispersibility of the thermoplastic elastomer in the resin composition. Tougheners may be used alone or in combination.

[0048] The content of the other resin in the resin composition of the present invention can be, for example, in the range of 0 to 20 parts by mass per 100 parts by mass of the polyolefin resin, and more preferably in the range of 0 to 10 parts by mass, and it is particularly preferable that no other resin is contained.

[0049] (Component (A)) Component (A) is at least one selected from aluminum hydroxide, magnesium hydroxide, and a phosphorus compound. Hereinafter, aluminum hydroxide and magnesium hydroxide may be referred to as component (A1), and the phosphorus compound may be referred to as component (A2). In the resin composition of the present invention, component (A) primarily functions as a flame retardant.

[0050] The content of component (A) is 10 to 60% by mass relative to the total amount of the resin composition of the present invention. If the content of component (A) is less than 10% by mass, the flame retardancy of the injection-molded article will be insufficient, and if it exceeds 60% by mass, the mechanical strength, particularly impact strength, of the injection-molded article will be insufficient. The content of component (A) relative to the total amount of the resin composition is preferably in the range of 10 to 45% by mass, more preferably 10 to 25% by mass.

[0051] The phosphorus content of the resin composition of the present invention is 5% by mass or less relative to the total amount. It is essential that the content of component (A) be within the above range and that the phosphorus content be 5% by mass or less relative to the total amount of the resin composition. The phosphorus content of the resin composition is preferably 2% by mass or less, more preferably 1% by mass or less, and even more preferably 0% by mass.

[0052] The phosphorus content (mass %) relative to the total amount of the resin composition can be measured, for example, using an energy dispersive X-ray fluorescence analyzer (for example, JSX-1000S (manufactured by JEOL Ltd.)).

[0053] The phosphorus compound of component (A2) has poor compatibility with polyolefin resins and therefore tends to separate during melting, and the separated compound bleeds out and remains on the surface of the molded article, which tends to deteriorate the appearance. If the phosphorus content of the resin composition is 5 mass% or less, deterioration of the appearance due to the bleed-out of component (A2) can be suppressed.

[0054] In component (A), the mass ratio of the contents of components (A1) and (A2) is preferably in the range of 100:0 to 30:70, more preferably 100:0 to 50:50, and even more preferably 100:0 to 75:25. When the mass ratio of the contents of components (A1) and (A2) is in the above range, the occurrence of flash and the like during continuous production in injection molding is suppressed, and it is easy to maintain good quality of molded products.

[0055] The resin composition of the present invention is a resin composition for injection molding. During injection molding, as the molten resin composition fills the mold cavity, air originally present in the cavity, decomposition gases of organic components in the resin composition generated while the resin composition is stagnating in the cylinder, and decomposition gases generated by shear heating as the resin composition passes through a gate in the mold are adiabatically compressed in the final filling section, resulting in significant heat generation and associated decomposition. To prevent this, an air vent is provided in the final filling section of the mold to allow gas escape. In particular, since the decomposition products of phosphorus compounds are acidic, when a resin composition contains phosphorus compounds, the air vent, which becomes hot, is prone to corrosion. As corrosion of the air vent progresses, the thickness of the air vent gradually increases, leading to the formation of flash in the molded product.

[0056] By setting the mass ratio of the contents of component (A1) and component (A2) within the above range, the content of the phosphorus compound in the resin composition can be relatively low, and as a result, corrosion of the air vent portion can be suppressed and the effect of suppressing the occurrence of burrs and the like in the injection-molded article can be particularly remarkable.

[0057] <Ingredient (A1)> Component (A1) is aluminum hydroxide or magnesium hydroxide. Component (A1) may contain only aluminum hydroxide or only magnesium hydroxide, or both. As described above, the proportion of component (A1) in component (A) is preferably 30 to 100 mass%, more preferably 50 to 100 mass%, and even more preferably 75 to 100 mass%.

[0058] The form of component (A1) is preferably particulate. The shape of the particles is not particularly limited, and examples include spherical, spindle-like, plate-like, scale-like, needle-like, and fibrous shapes. When component (A1) is particulate, the aspect ratio measured in the same manner as for component (C) is less than 10.

[0059] In the resin composition, component (A1) preferably has an average particle size in the range of 0.01 to 100 μm, more preferably 0.1 to 10 μm, and even more preferably 0.2 to 2 μm. The average particle size of component (A1) can be considered to be the same as the primary particle size of aluminum hydroxide or magnesium hydroxide particles (hereinafter also referred to as "raw material particles") used in producing the resin composition. The primary particle size of the raw material particles measured by laser diffraction / scattering can be measured as the volume-based median diameter (D50).

[0060] The raw material particles of component (A1) may be surface-modified with a surface modifier as needed. Examples of surface modifiers that can be used for surface modification include alkylsilazane compounds such as hexamethyldisilazane (HMDS), alkylalkoxysilane compounds such as dimethyldimethoxysilane, dimethyldiethoxysilane, trimethylmethoxysilane, methyltrimethoxysilane, and butyltrimethoxysilane, chlorosilane compounds such as dimethyldichlorosilane and trimethylchlorosilane, silicone oil, silicone varnish, and various fatty acids. These surface modifiers may be used alone or in combination.

[0061] <Ingredient (A2)> Component (A2) is a phosphorus compound. Component (A2) can be any compound containing phosphorus without any particular limitation. When component (A2) is used as component (A) as described above, it is used so that the phosphorus content relative to the total amount of the resin composition is 5% by mass or less. As described above, the phosphorus content relative to the total amount of the resin composition is preferably 2% by mass or less, more preferably 1% by mass or less, and even more preferably 0% by mass. From this perspective, the proportion of component (A2) in component (A) is preferably 0 to 70% by mass, more preferably 0 to 50% by mass, and even more preferably 0 to 25% by mass.

[0062] Examples of phosphorus compounds include salts of phosphinic acid, phosphonic acid, phosphoric acid, etc. with metals, ammonium, etc., and ester compounds of phosphinic acid, phosphonic acid, phosphoric acid, etc. Among these, phosphate ester compounds (described in detail later) are preferred as component (A2) from the viewpoint of flame retardancy.

[0063] Specific examples of the salts include metal phosphinates, particularly aluminum phosphinate and zinc phosphinate, metal phosphonates, particularly aluminum phosphonate, calcium phosphonate, and zinc phosphonate, as well as hydrates of the corresponding metal phosphonates, ammonium phosphate, and ammonium polyphosphate.

[0064] 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.

[0065] Examples of phosphonate compounds include methylphosphonic acid, dimethyl methylphosphonate, diethyl methylphosphonate, ethylphosphonic acid, propylphosphonic acid, butylphosphonic acid, 2-methyl-propylphosphonic acid, t-butylphosphonic acid, 2,3-dimethylbutylphosphonic acid, octylphosphonic acid, phenylphosphonic acid, and dioctylphenylphosphonate.

[0066] 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 FRX Polymers, Chelmsford, USA)), zinc bis(diethylphosphinate), aluminum tris(diethylphosphinate), melamine phosphate, melamine pyrophosphate, melamine polyphosphate, melamine poly(aluminum phosphate), melamine poly(zinc phosphate), melamine methylphosphonate, guanylurea phosphate, guanidine phosphate, ethylenediamine phosphate, and phosphazene compounds such as phenoxyphosphazene oligomers may also be used as component (A2).

[0067] As the phosphorus compound, one of these may be used alone or two or more may be used in combination as the component (A2).

[0068] [Phosphate ester compounds] The phosphate ester compound may be an aliphatic phosphate ester compound or an aromatic phosphate ester compound, and is preferably an aromatic phosphate ester compound. When an aromatic phosphate ester compound is used as component (A), it is thought that the NOR type HALS generates radicals more stably, making it easier to exhibit flame retardant effects.

[0069] Examples of the phosphate ester compound include a monomeric phosphate ester compound obtained by reacting phosphoric acid with an aliphatic or aromatic alcohol, and an aromatic condensed phosphate ester compound which is a reaction product of phosphorus oxychloride, a dihydric phenolic compound, and phenol (or an alkylphenol).

[0070] Specific examples of the phosphate ester compound 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.

[0071] Moreover, the phosphate ester compound is preferably a condensed phosphate ester compound, which is a condensed type, from the viewpoint of heat resistance, etc. Examples of the condensed phosphate ester compound include aromatic condensed phosphate ester compounds represented by the following chemical formula (A2).

[0072] [ka]

[0073] 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, an alkoxy group having 1 to 10 carbon atoms, or a halogen atom; R 1 ~R 5 may be the same or different. Multiple (5) R 1 may be the same or different. 2 , R 3 , R 4 and R 5The same applies to n. n is an integer of 1 to 30, and preferably an integer of 1 to 10.

[0074] Examples of the alkyl group include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, an amyl group, a tert-amyl group, a hexyl group, a 2-ethylhexyl group, an n-octyl group, a nonyl group, and a decyl group.

[0075] Examples of the cycloalkyl group include a cyclohexyl group, etc. Examples of the aryl group include a phenyl group, a cresyl group, a xylyl group, a 2,6-xylyl group, a 2,4,6-trimethylphenyl group, a butylphenyl group, and a nonylphenyl group.

[0076] Examples of the alkoxy group include a methoxy group, an ethoxy group, a propoxy group, a butoxy group, etc. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, etc.

[0077] As described above, the aromatic condensed phosphate ester compound is a reaction product of phosphorus oxychloride, a dihydric phenolic compound, and phenol (or an alkylphenol). The aromatic condensed phosphate ester compound represented by the structure of formula (A2) is a compound in which the dihydric phenolic compound is a resorcinol (hereinafter also referred to as a "resorcinol compound") which may have a substituent. The aromatic condensed phosphate ester compound may be a compound obtained by using 4,4'-biphenol or bisphenol A (each of which may have a substituent) instead of the resorcinol compound. Specifically, an aromatic condensed phosphate ester compound having a 4,4'-biphenol residue or a bisphenol A residue, each of which may have a substituent, instead of the resorcinol compound residue in formula (A2) can be used in the present invention.

[0078] Commercially available phosphate ester compounds may be used, such as PX-200 (resorcinol bis-dixylenyl phosphate) and CR-733S (resorcinol bis-diphenyl phosphate), both manufactured by Daihachi Chemical Industry Co., Ltd.

[0079] (Component (B)) Component (B) is a NOR-type HALS. The content of component (B) is 0.05 to 5 mass% relative to the total amount of the resin composition of the present invention. As described above, component (B) has the effect of reducing the melt viscosity of the resin composition during injection molding, and thereby the resin composition of the present invention is said to have the effect of suppressing mold wear. If the content of component (B) is less than 0.05 mass%, the effect of suppressing mold wear when used in injection molding is not sufficiently obtained. If the content of component (B) is more than 5 mass%, the mechanical strength, particularly bending strength, of the injection-molded product is insufficient. The content of component (B) relative to the total amount of the resin composition is preferably in the range of 0.1 to 2 mass%, more preferably in the range of 0.2 to 1 mass%.

[0080] In addition to the above-mentioned functions, component (B) also has the function of imparting flame retardancy to injection-molded articles. Furthermore, NOR-type HALS is well known as a light stabilizer, and its addition can also impart light resistance.

[0081] NOR-type HALS is HALS with an alkoxyimino group (>N-OR). An alkoxyimino group is an imino group (>NH) with an alkoxy group structure, where the H in the NH portion of the imino group (>NH) remains as H, an NR-type where the H is replaced by an alkyl group (R (which has the same meaning as the R in alkoxy group), typically a methyl group), or an N-methyl type where the H is replaced by an alkoxy group. This N-alkoxy group easily captures alkylperoxy radicals (RO2·) to form radicals and exerts a flame-retardant effect. In addition, in the resin composition of the present invention, it functions to suppress the above-mentioned mold wear.

[0082] On the other hand, N-methyl type hindered amine compounds or NH type hindered amine compounds are poor in the function of suppressing mold wear, and furthermore, have low flame retardant effects.

[0083] In the alkoxy group (-OR), R represents a substituted or unsubstituted, saturated or unsaturated hydrocarbon group. Examples of R include an alkyl group, an aralkyl group, and an aryl group. The alkyl group may be linear, branched, or cyclic, or may be a combination of these.

[0084] 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 NOR-type HALS described in JP-A-2002-507238, WO-A-2005 / 082852, WO-A-2008 / 003605, etc.

[0085] An example of the NOR type HALS is a compound represented by the structure of the following formula (B).

[0086] [ka]

[0087] [In formula (B), G 1 and G 2 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 together form a bridging moiety, which can be further attached to the organic group via an ester group, an ether group, an amide group, an amino group, a carbonyl group, or a urethane group. E represents an alkoxy group having 1 to 18 carbon atoms, a cycloalkoxy group having 5 to 12 carbon atoms, an aralkoxy group having 7 to 25 carbon atoms, or an aryloxy group having 6 to 12 carbon atoms.]

[0088] The NOR type HALS represented by formula (B) is preferably a polymer type. The polymer type is generally an oligomeric or polymeric compound. The polymer type is excellent in flame retardancy and heat resistance. The number of repeating units of the polymer type oligomeric or polymeric compound is preferably 2 to 100, more preferably 5 to 80.

[0089] Furthermore, as the NOR type HALS represented by formula (B), for example, a compound represented by the following formula (1) can be used.

[0090] [ka]

[0091] In the above formula (1), R 1 ~R 4 R represents a hydrogen atom or an organic group of the following formula (2). 1 ~R 4 At least one of the groups is an organic group represented by the following formula (2).

[0092] [ka]

[0093] In the formula, R 5 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; R 6 , R 7 , R 8 and R 9 R represents an alkyl group having 1 to 4 carbon atoms. 10 represents a hydrogen atom or a linear or branched alkyl group having 1 to 12 carbon atoms.

[0094] R 5Of the alkyl groups having 1 to 17 carbon atoms, methyl, propyl, or octyl is preferred. Of the cycloalkyl groups having 5 to 10 carbon atoms, cyclohexyl is preferred. Of the phenyl groups or phenylalkyl groups having 7 to 15 carbon atoms, phenyl is preferred. R 6 ~R 9 Among the alkyl groups having 1 to 4 carbon atoms, a methyl group is preferred. R 10 Among the linear or branched alkyl groups having 1 to 12 carbon atoms, an n-butyl group is preferred.

[0095] 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 is preferably an organic group of formula (2).

[0096] 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-tetramethylpiperidin-4-yl)sebacate;2,4-Bis[(1-cyclohexyloxy-2,2,6,6-tetramethylpiperidin-4-yl)butylamino]-6-(2-hydroxyethylamino)-s-triazine;Bis(1-cyclohexyloxy-2,2,6,6-tetramethylpiperidin-4-yl)adipate;4,4´-Hexamethylenebis(amino- oligomeric compounds which are condensation products of 4,4'-hexamethylenebis(amino-2,2,6,6-tetramethylpiperidine) and 2,4-dichloro-6-[(1-octyloxy-2,2,6,6-tetramethylpiperidin-4-yl)butylamino]-s-triazine end-capped with 2-chloro-4,6-bis(dibutylamino)-s-triazine; Oligomeric compounds that are condensation products of 2,4-bis[(1-cyclohexyloxy-2,2,6,6-tetramethylpiperidin-4-yl)butylamino]-s-triazine with 2,4-bis[(1-cyclohexyloxy-2,2,6,6-piperidin-4-yl)-6-chloro-s-triazine]; and products of the reaction of peroxidized 4-butylamino-2,2,6,6-tetramethylpiperidine with 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-tetramethylpiperidin-4-yl)n-butylamino]-s-triazin-6-yl}-3,3'-ethylenediiminodipropylamine; bis(1-undecanoxy-2,2,6,6-tetramethylpiperidin-4-yl)carbonate; 1-undecyloxy-2,2,6,6-tetramethylpiperidin-4-one; bis(1-stearyloxy-2,2,6,6-tetramethylpiperidin-4-yl)carbonate.

[0097] Commercially available NOR-type HALS may be used. Examples of commercially available NOR-type HALS include Flamestat NOR116FF, TINUVIN NOR371, TINUVIN XT850FF, TINUVIN XT855FF, and TINUVIN PA123 manufactured by BASF, and LA-81 and FP-T80 manufactured by ADEKA. One type of NOR-type HALS may be used alone, or two or more types may be used in combination.

[0098] (Component (C)) Component (C) is a fibrous filler with an aspect ratio of 10 or more. The aspect ratio of component (C) is an average aspect ratio determined by the following method. Note that hereinafter, a fibrous filler with an aspect ratio of 10 or more may also be referred to as fibrous filler (C).

[0099] <Method for measuring aspect ratio> The aspect ratio of a fibrous filler is expressed as the value obtained by dividing the fiber length (length of the fiber) of the fibrous filler by the fiber diameter (the smallest diameter among the diameters of the cross section perpendicular to the longitudinal direction of the fiber, i.e., the smallest value of the fiber thickness). In the present invention, for the fibrous filler in the resin composition, the fiber length and fiber diameter of 100 fibrous fillers are measured, the aspect ratio of each fibrous filler is determined, and the average value of the 100 fibrous fillers (average aspect ratio) is calculated as the aspect ratio.

[0100] The shape of the fibrous filler used as a raw material in producing a resin composition changes as the resin composition undergoes production processes such as kneading, pulverization, and molding. For example, the raw fibrous filler often breaks during the production process, causing the fiber length to change. Therefore, in the present invention, the fiber length and fiber diameter of the fibrous filler present in the resin composition are measured, and the aspect ratio of the fibrous filler is calculated.

[0101] Specifically, the resin composition is heated in an electric furnace or the like to burn and remove the resins including polyolefin resins, the organic components in component (A), and the organic components in component (B), and the fibrous filler is extracted from the inorganic residue. The heating temperature is set to a temperature at which the organic components can be burned, for example, 500°C or higher. The inorganic residue includes the inorganic components in component (A) and the fibrous filler. The inorganic components in component (A) are not fibrous in shape and can be distinguished from the fibrous filler. 100 fibrous fillers are selected randomly from the inorganic residue. The constituent material of component (C), the fibrous filler (C), is an inorganic material.

[0102] The predetermined number of fibrous fillers in the resin composition thus obtained are observed with a scanning electron microscope, a transmission electron microscope, an atomic force microscope or the like to measure the fiber length and fiber diameter.

[0103] The aspect ratio of the fibrous filler (C) is 10 or more. The aspect ratio is preferably 20 or more, more preferably 50 or more. When a fibrous filler with an aspect ratio of less than 10 is used, an injection-molded article of the resin composition does not have sufficient mechanical strength, particularly bending strength. From the viewpoint of the fluidity of the resin during injection molding, the aspect ratio of the fibrous filler (C) is preferably, for example, 500 or less, and more preferably 100 or less.

[0104] The average fiber length of the fibrous filler (C) determined by the above method is, for example, preferably 0.01 to 1 mm, more preferably 0.02 to 0.5 mm, and the average fiber diameter of the fibrous filler (C) is, for example, preferably 0.001 to 0.05 mm, more preferably 0.005 to 0.02 mm.

[0105] The content of component (C) is 1 to 20% by mass relative to the total amount of the resin composition of the present invention. If the content of component (C) is less than 1%, the mechanical strength, particularly the bending strength, of the injection-molded article will be insufficient, while if it exceeds 20% by mass, the effect of suppressing mold wear when used in injection molding will not be sufficiently obtained. The content of component (C) relative to the total amount of the resin composition is preferably in the range of 2 to 15% by mass, more preferably in the range of 5 to 10% by mass.

[0106] Examples of the fibrous filler (C) include glass fiber, carbon fiber, carbon nanotube, metal fiber, mineral fiber, ceramic fiber, rock wool, wollastonite, potassium titanate, barium titanate, sepiolite, halloysite, imogolite, etc., which have an aspect ratio of 10 or more. These fibrous fillers (C) may be used alone or in combination of two or more.

[0107] As the fibrous filler (C), halloysite with an aspect ratio of 10 or more is preferred from the viewpoint of suppressing mold wear. Halloysite is represented by the composition formula Al2Si2O5(OH)4 and is typically available as a tubular nanofiller with a fiber diameter of several tens of nanometers and a fiber length of several hundred to several thousand nanometers. Halloysite is known for its unique characteristics, such as its high gas adsorption ability, due to its nano-sized structure and the highly active Al(OH) structure inside.

[0108] When halloysite is used as the fibrous filler (C), the effects of suppressing corrosion of the air vent portion of the injection molding mold described above and suppressing the occurrence of burrs and the like in the injection molded product are particularly remarkable.

[0109] The fibrous filler used in producing the resin composition (hereinafter also referred to as "raw fiber filler" to distinguish it from the fibrous filler (C) in the resin composition) has an aspect ratio larger than that of the fibrous filler (C), taking into account breakage during the production process, for example, depending on the constituent material of the fibrous filler. For example, when the raw fiber filler is made of a constituent material that is expected to break during the production process, the aspect ratio of the raw fiber filler is preferably 20 or more, more preferably 100 or more, depending on the type of material.

[0110] It is preferable to pre-treat the raw fibrous filler with a coupling agent such as an isocyanate compound, an organic silane compound, an organic titanate compound, an organic borane compound, or an epoxy compound in order to obtain better mechanical strength.

[0111] (Other additives) The resin composition of the present invention may contain known additives in addition to the polyolefin resin-containing resin, component (A), component (B), and component (C) to the extent that the effects of the present invention are not impaired. Examples of other additives include flame retardants other than component (A) and component (B), anti-drip agents, antioxidants, lubricants, etc.

[0112] <Other flame retardants> The other flame retardant may be an organic flame retardant or an inorganic flame retardant. Examples of organic flame retardants include bromine compounds. Examples of inorganic flame retardants include antimony compounds and metal hydroxides other than component (A1).

[0113] <Anti-drip agent> Anti-drip agents are added to prevent the resin material from dripping during combustion and to improve flame retardancy, and examples of the anti-drip agent include fluorine-based anti-drip agents, silicone rubbers, layered silicates, etc. Anti-drip agents may be used alone or in combination of two or more.

[0114] <Antioxidants> Examples of the antioxidant include hindered phenols.

[0115] <Lubricant> The lubricant may be one or more selected from the group consisting of fatty acid salts, fatty acid amides, silane polymers, solid paraffin, liquid paraffin, calcium stearate, zinc stearate, stearic acid amide, silicone powder, methylene bisstearic acid amide, and N,N'-ethylene bisstearic acid amide.

[0116] 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, for example, within a range of about 0.1 to 30% by mass, preferably within a range of 0.1 to 20% by mass, based on the total amount of the resin composition, and preferably 30% by mass or less in total.

[0117] [Method of producing resin composition] The resin composition of the present invention can be obtained by melt-kneading raw materials, such as a resin containing the polyolefin resin, component (A), component (B), component (C), and other additives that may be contained as needed, to obtain the resin composition of the present invention. In particular, the aspect ratio of component (C) may change (decrease) from that of the raw fiber filler to that of the fibrous filler (C) during the manufacturing process.

[0118] It is preferable to apply a manufacturing method for the resin composition of the present invention, which includes, for example, a first step of melt-kneading the polyolefin resin, component (A), and component (B) to obtain a resin mixture, taking into account the change in aspect ratio and depending on the constituent materials of the raw fiber filler, and a second step of melt-kneading the resin mixture and the raw fiber filler of the fibrous filler having an aspect ratio of 10 or more.

[0119] When the resin composition of the present invention contains other resins or other additives, the other resins or other additives may be melt-kneaded in the first step or in the second step.

[0120] In addition, pellets obtained by melt-kneading the raw material fibrous filler with a resin such as a polyolefin resin may be used. At least a portion of the polyolefin resin contained in the resin composition may be melt-kneaded in the first step, and the remainder may be added and melt-kneaded in the second step, if necessary. The same applies to component (A) and component (B).

[0121] In the production method of the present invention, the melt-kneading in the first and second steps is carried out using kneading devices such as a Banbury mixer, a roll, a plastograph, an extruder (such as a single-screw extruder or a multi-screw extruder (e.g., a twin-screw extruder)), and a kneader. Among these, it is preferable to carry out the melt-kneading using an extruder because of its high production efficiency. Furthermore, it is preferable to use a multi-screw extruder for the melt-kneading because it can impart high shear strength, and it is more preferable to use a twin-screw extruder. Here, the term extruder is used in a category that includes an extrusion kneader.

[0122] In the production method of the present invention, different kneading devices may be used in the first and second steps, but it is preferable to use an extruder, particularly a twin-screw extruder, in both steps.

[0123] The temperature during melt-kneading (melt-kneading temperature) is set to be equal to or higher than the melting temperature of the polyolefin resin in both the first and second steps. The melt-kneading 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-kneading temperature is preferably 180 to 270°C, more preferably 180 to 230°C. Within the above temperature range, the melt-kneading temperatures in the first and second steps may be the same or different. When an extruder is used for melt-kneading, the kneading melt temperature corresponds to the cylinder temperature.

[0124] When an extruder is used for melt-kneading, the screw rotation speed is preferably in the range of 50 to 300 rpm in both Step 1 and Step 2. The screw rotation speeds in Step 1 and Step 2 may be the same or different. The discharge rate of the resin mixture or resin composition from the extruder in Step 1 and Step 2 is preferably in the range of 1 to 50 kg / hr, respectively.

[0125] In the present invention, the first and second steps can be carried out continuously using the same extruder, which is preferable from the viewpoint of productivity. For example, the first and second steps can be carried out continuously by using a twin-screw extruder, supplying raw material components other than the raw material fibrous filler from a hopper installed at the rear end of the cylinder of the twin-screw extruder, and supplying the raw material fibrous filler from a side feeder installed at the front, for example, center, of the cylinder. Note that the front end of the cylinder is the discharge port for the resin composition, and the rear end corresponds to the vicinity of the end of the cylinder opposite to the discharge port.

[0126] Before the melt-kneading in the first step, the components may be mixed (dry blended) in advance using various mixers such as a tumbler or a high-speed mixer known as a Henschel mixer.

[0127] In the production method of the present invention, the kneaded mixture is extruded into a strand shape in the second step, and then the kneaded mixture extruded into a strand shape can be processed into a pellet shape, a flake shape, or the like.

[0128] The resin composition of the present invention can be in various forms such as powder, granules, tablets, pellets, flakes, fibers, and liquid.

[0129] The use of the resin composition of the present invention enables economical production of injection-molded articles with stable quality, for example, by suppressing wear of the gate portion of the mold and corrosion of the air vent portion during long-term continuous production. Furthermore, the injection-molded articles obtained using the resin composition of the present invention have excellent appearance, mechanical strength (rigidity and toughness), and flame retardancy.

[0130] For example, the flexural strength of an injection-molded article formed from the resin composition of the present invention, as measured in a bending test according to JIS-K 7171, is preferably 25 MPa or more, more preferably 35 MPa or more, and even more preferably 50 MPa or more. If the flexural strength is 25 MPa or more, the rigidity of the molded article can be evaluated as being sufficient for practical use.

[0131] For example, an injection-molded article molded from the resin composition of the present invention has a Charpy impact strength of 8 kJ / m or less as measured in a Charpy impact test (notched) performed in accordance with JIS-K7110. 2 It is preferable that the concentration is 15 kJ / m or more. 2 More preferably, it is 20 kJ / m or more. 2 It is more preferable that the Charpy impact strength is 8 kJ / m or more. 2 If the toughness is equal to or greater than this, the molded product can be evaluated as having no practical problems.

[0132] Here, flame retardancy is a type of flame resistance, and refers to the property of burning slowly but continuing to burn to a certain extent. Flame resistance is evaluated by standards such as JIS and ASTM, but the UL standard is generally given particular importance. The UL standard is established by the American company Underwriters Laboratories and is evaluated by the same company.

[0133] When an injection-molded article molded from the resin composition of the present invention is evaluated using a test piece of a predetermined size according to the above-mentioned UL standard, it is preferably judged as V-2 or higher, more preferably V-1 or higher, and even more preferably V-0, in a combustion test in accordance with UL-94.

[0134] (molded product) The resin composition of the present invention can be used to produce an injection-molded article, which, as described above, can provide a product with excellent appearance, mechanical strength (rigidity and toughness), and flame retardancy.

[0135] When producing an injection-molded product, a conventionally known injection molding machine can be used. An injection-molded product can be produced, for example, by melting a resin composition in a cylinder, injecting the molten resin composition into a mold, and then cooling the mold. The injection speed and pressure are adjusted appropriately. Injection molding conditions include, for example, a cylinder temperature (melt temperature) of 180 to 230°C, an injection speed of 30 to 200 mm / sec, and a pressure of 500 to 1000 kgf / cm. 2 The mold temperature is preferably 40 to 80°C.

[0136] The fiber length, fiber diameter, and aspect ratio of the fiber filler in the injection-molded product can be measured or calculated using the same method as for the fiber filler in the resin composition. The fiber length, fiber diameter, and aspect ratio of the fiber filler in the injection-molded product obtained using the resin composition of the present invention are preferably within ranges that can fully exhibit the effects of the present invention. Specifically, the average fiber length of the fiber filler is preferably 0.01 to 1 mm, the average fiber diameter is preferably 0.001 to 0.05 mm, and the average aspect ratio is preferably within the ranges of 10 to 100.

[0137] The injection-molded article obtained by injection molding from the resin composition of the present invention is not particularly limited, and examples thereof include electric and electronic parts, electrical components, exterior parts, and interior parts in the fields of home appliances and automobiles, as well as various packaging materials, household goods, office supplies, piping, and agricultural materials. [Example]

[0138] The present invention will be specifically described below with reference to examples, but the present invention is not limited to these. In the examples, the terms "parts" and "%" are used, but unless otherwise specified, they represent "parts by mass" or "% by mass."

[0139] [Resin Composition: Examples 1 to 18, Comparative Examples 1 to 8] The following commercially available products were prepared as raw material components to be contained in the resin compositions of the Examples and Comparative Examples.

[0140] <Resin> Polypropylene resin: Prime Polypro J715M (product name, manufactured by Prime Polymer Co., Ltd.) Polyethylene resin: HJ560 (product name, manufactured by Japan Polyethylene Corporation)

[0141] <Ingredient (A1)> Aluminum hydroxide: KH-101 (product name, manufactured by KC Corporation, particles with an average primary particle size of 1.0 μm) Magnesium hydroxide: Magseeds N-6 (product name, manufactured by Konoshima Chemical Co., Ltd., particles with an average primary particle size of 1.2 μm and surface-modified with higher fatty acids)

[0142] <Ingredient (A2)> Phosphate ester compound: PX-200 (product name, Daihachi Chemical Industry Co., Ltd., resorcinol bis-dixylenyl phosphate) Ammonium polyphosphate: Taien K (product name, manufactured by Taihei Chemical Industry Co., Ltd.) Metal phosphonate: calcium phosphonate (Kanto Chemical Co., Ltd.)

[0143] <Ingredient (B)> NOR-type HALS: Flamestat NOR116FF (product name, manufactured by BASF, N,N',N'''-tris{2,4-bis[(1-cyclohexyloxy-2,2,6,6-tetramethylpiperidin-4-yl)n-butylamino]-s-triazin-6-yl}-3,3'-ethylenediiminodipropylamine)

[0144] <HALS other than ingredient (B)> NH-type HALS: Tinuvin 770DF (BASF, bis(2,2,6,6-tetramethyl-4-piperidyl) sebacate) NR (methyl) type HALS: Tinuvin 765 (BASF, a mixture of bis(1,2,2,6,6-pentamethyl-4-piperidyl) sebacate and methyl-1,2,2,6,6-pentamethyl-4-piperidyl sebacate)

[0145] <Raw fibrous filler for component (C)> Glass fiber: ECS03T-430 (manufactured by Nippon Electric Glass Co., Ltd.; average fiber diameter 13 μm, average fiber length 3 mm) Long glass fiber: Funcster LR-24A (manufactured by Japan Polypropylene Corporation; polypropylene masterbatch pellets containing 40% by mass of long glass fiber; pellet length: 10 mm) was used. In Tables I and II, the long glass fiber content in the pellets (Funcster LR-24A) blended into the resin composition is shown in the column for component (C), and the amount of polypropylene content, including the amount of J715M, is shown in the column for resin components. Halloysite: Doragonite APA:M (manufactured by Fimatec; average aspect ratio 18) Wollastonite: WFC10 (Nippon Talc Co., Ltd.; average aspect ratio 14) Potassium titanate: Tismo D (Otsuka Chemical Co., Ltd.; average aspect ratio 30) Carbon fiber: Chopped carbon fiber HT C413 (Teijin, average fiber diameter 7 μm, average fiber length 6 mm)

[0146] (Production of Resin Composition) In each example and comparative example, each component was used in the content (mass%) shown in Tables I and II. In the column for the content (mass%) of each component, a blank indicates that the component was not contained.

[0147] Melt mixing was performed using a twin-screw extruder ("TEX30α" manufactured by Japan Steel Works) at a cylinder temperature of 200°C and a screw rotation speed of 150 rpm. For all but Comparative Example 1, the raw material components except the fibrous filler were dry-blended in advance and then fed from a hopper installed at the rear end of the twin-screw extruder cylinder, and the fibrous filler was fed from a side feeder installed in the center of the cylinder. For Comparative Example 1, all raw material components including the fibrous filler were dry-blended in advance and then fed from a hopper installed at the rear end of the twin-screw extruder cylinder. In the column for the resin composition production method in Tables I and II, Comparative Example 1 is listed as "all at once," and all but Comparative Example 1 are listed as "separately."

[0148] The strands discharged from the extruder were cut by a pelletizer and processed into pellets of 2 mm diameter x 3 mm length to prepare a resin composition.

[0149] [Analysis of components in resin composition] (1) Aspect ratio measurement of fibrous filler The pellets of each resin composition obtained above were heated in an electric furnace at 600°C for 4 hours, and the organic matter was incinerated to obtain a residue. 100 fibrous fillers were randomly selected from the residue and observed with a scanning electron microscope (SEM) to measure the fiber length and fiber diameter of each fibrous filler. The aspect ratio of each fibrous filler was calculated, and the average value was calculated to obtain the average aspect ratio.

[0150] (2) Phosphorus concentration (mass%) measurement The phosphorus content (mass%) of the pellets of each resin composition obtained above was measured using an energy dispersive X-ray fluorescence analyzer (JSX-1000S manufactured by JEOL Ltd.).

[0151] <Evaluation> The resin compositions of Examples 1 to 18 and Comparative Examples 1 to 8 obtained above were evaluated for mechanical strength (flexural strength and impact strength), flame retardancy, continuous moldability, and molded product appearance. The results are shown in Tables I and II.

[0152] (Test piece manufacturing conditions) Pellets of the resin compositions of each Example and Comparative Example were dried at 80°C for 4 hours and then molded into evaluation articles using an injection molding machine (J140AD-110H, manufactured by The Japan Steel Works, Ltd.) The cylinder temperature during molding was 200°C, and the primary injection pressure was 1000 kgf / cm. 2 , secondary pressure 500kgf / cm 2 The injection speed was 50 mm / sec and the mold temperature was 50°C.

[0153] (1) Bending strength measurement Using the above molding conditions, rectangular test pieces measuring 80 mm x 10 mm x 4 mm were molded, and a bending test was carried out in accordance with JIS-K7171 to measure the bending strength [MPa] and evaluate it according to the following criteria: If the bending strength was 25 MPa or more, it was determined that the strength of the molded product was sufficient for practical use.

[0154] (Evaluation criteria) ◎: 50MPa or more 〇: 35MPa or more, less than 50MPa △: 25 MPa or more, less than 35 MPa ×: Less than 25 MPa

[0155] (2) Impact strength measurement Under the above molding conditions, rectangular test pieces (notched) of 80 mm x 10 mm x 4 mm were prepared in accordance with JIS-K7110 and subjected to Charpy impact tests (notched). Charpy impact strength [kJ / m 2 ] was measured and evaluated according to the following criteria. 2 If the toughness of the molded product was equal to or greater than this, it was determined that there was no problem in practical use.

[0156] (Evaluation criteria) ◎: 20kJ / m 2 End 〇: 15kJ / m 2 More than 20kJ / m 2 less than △:8kJ / m 2 More than 15kJ / m 2 less than ×:8kJ / m 2 less than

[0157] (3) Combustion test (flame retardancy evaluation) Using the molding conditions described above, rectangular test pieces measuring 125mm x 12.5mm x 1.6mm were prepared and subjected to a flammability test in accordance with UL-94. They were evaluated according to the following criteria. Note that products that achieved a flammability test rating of V-2 or higher were deemed to be suitable for practical use.

[0158] (Evaluation criteria) 〇: The judgment was V-0, V-1, or V-2. ×: The evaluation was below V-2.

[0159] (4) Continuous molding (Continuous molding test) In the mold used to prepare the bending test pieces used to evaluate bending strength, a nested gate section was provided at the longitudinal end. The material of the nest was S50C carbon steel for mechanical structures. The gate size was 4 mm wide x 1.5 mm thick, and the land length was 4 mm. Furthermore, a nested air vent section was provided at the end opposite the gate section. The material of the nest was S50C carbon steel for mechanical structures. The air vent size was 4 mm wide x 0.02 mm thick, and the land length was 1 mm. A 2 mm thick air guide groove was provided from the end of the land toward the outer periphery of the mold.

[0160] Under the above molding conditions, a continuous molding test was conducted for each resin composition of the Examples and Comparative Examples, in which bending test pieces were molded continuously for 5,000 shots. For each resin composition of the Examples and Comparative Examples, the gate and air vent inserts were replaced with new ones before the start of molding, and then the same test was conducted. If the cross-sectional area of ​​the gate increases due to wear, the filling amount of the molded product changes, leading to problems such as inconsistent quality and increased likelihood of burrs.

[0161] (4-1) Change in gate cross-sectional area after continuous molding test After the continuous molding test, the nest at the gate was removed and the width and thickness of the gate were measured using an optical microscope to determine the cross-sectional area ratio of the gate before molding began and after 5,000 shots (continuous molding test).

[0162] Gate cross-sectional area = gate width x gate thickness Gate cross-sectional area ratio (AR) = Gate cross-sectional area after 5,000 molding shots / Gate cross-sectional area before molding begins

[0163] (Evaluation criteria) ○: Gate cross-sectional area ratio (AR) < 1.002 (a practically desirable level) △: 1.002≦gate cross-sectional area ratio (AR)<1.01 (not desirable, but not problematic in practice) ×: 1.01≦gate cross-sectional area ratio (AR); (Level at which practical problems occur)

[0164] (4-2) Evaluation of flash at the air vent after continuous molding test After the continuous molding test, the insert in the air vent section was removed and the appearance was visually inspected, and the state of burrs on the molded product at the 5,000th shot was observed using an optical microscope.

[0165] (Evaluation criteria) ⊚: No discoloration was observed in the air vent part of the mold, and no burrs were observed in the air vent processed part of the molded product (a level that is very desirable for practical use). Good: Slight discoloration was observed in the air vent area of ​​the mold, but no burrs were observed in the air vent processed area of ​​the molded product (a level that is acceptable for practical use). Δ: Discoloration was observed at the air vent portion of the mold, and slight burrs were observed at the air vent processing portion of the molded product (not desirable, but at a level that does not cause any problems in practical use).

[0166] (5) Appearance of molded product In the molding of the bending test pieces described above, the appearance of the molded product was visually inspected and evaluated according to the following evaluation criteria.

[0167] (Evaluation criteria) ◯: No liquid deposits were observed on the surface of the molded article (a level that is preferable for practical use). ×: Liquid deposits were observed on the surface of the molded product (to a level that would cause practical problems).

[0168] [Table 1]

[0169] [Table 2]

[0170] It is clear from Tables I and II that by using the resin composition of the present invention, injection molded articles excellent in mechanical strength, flame retardancy and appearance can be produced economically with stable quality.

Claims

1. A resin composition for injection molding containing a polyolefin resin, Relative to the total amount of the resin composition 10 to 60% by mass of at least one selected from aluminum hydroxide, magnesium hydroxide, and phosphorus compounds, 0.05 to 5% by mass of a NOR-type hindered amine compound, and The composite material contains 1 to 20 mass% of a fibrous filler having an aspect ratio of 10 or more and 60 or less and an average fiber length of 0.01 to 1 mm, and the phosphorus content relative to the total amount of the resin composition is 5% by mass or less; The fibrous filler is A resin composition comprising at least one of glass fiber, wollastonite, potassium titanate, and halloysite.

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

3. 3. The resin composition according to claim 1, wherein the phosphorus compound includes a phosphate ester compound.

4. The resin composition according to any one of claims 1 to 3, characterized in that a mass ratio of a total content of the aluminum hydroxide and the magnesium hydroxide to a content of the phosphorus compound is within a range of 100:0 to 75:

25.

5. 5. The resin composition according to claim 1, wherein the aspect ratio of the fibrous filler is 50 or more and 60 or less.

6. The resin composition according to any one of claims 1 to 5, wherein the fibrous filler contains halloysite.

7. A method for producing a resin composition according to any one of claims 1 to 6, comprising: a first step of melt-kneading the polyolefin resin, at least one compound selected from the group consisting of aluminum hydroxide, magnesium hydroxide, and a phosphorus compound, and the NOR-type hindered amine compound to obtain a resin mixture; a second step of melt-kneading the resin mixture and raw material components of a fibrous filler having an aspect ratio of 10 or more and 60 or less and an average fiber length of 0.01 to 1 mm, wherein the fibrous filler is at least one of glass fiber, wollastonite, potassium titanate, and halloysite.

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