Reinforced polypropylene resin composition

Abstract

The present invention addresses the problem of providing a molded body which is produced from a reinforced polypropylene resin composition in which a glass fiber, a flame retardant, and an acid-modified polypropylene resin are blended, and which has a high commercial value in terms of appearance, while maintaining the flame retardancy and mechanical properties of the molded body. Provided is a reinforced polypropylene resin composition which is characterized by containing a polypropylene resin (A), a phosphorus-based flame retardant (B), and a glass fiber (C), the polypropylene resin (A) contains: an unmodified polypropylene resin (A-1) having an MFR of 100-400 g / 10 minutes under the conditions of 230 DEG C and 2.16 kg load; and an acid-modified polypropylene resin (A-2) having an MFR of 100-1000 g / 10 minutes under the conditions of 190 DEG C and 2.16 kg load, an acid-modified monomer grafting amount of 0.5-3.0 mass%, and an acid-modified monomer grafting efficiency of more than 60%.

Description

Technical Field

[0001] The present invention relates to a reinforced polypropylene resin composition capable of obtaining a molded body having excellent mechanical properties and flame retardancy. Background Art

[0002] Glass fiber-reinforced polypropylene resin molded articles are lightweight, have excellent rigidity and heat resistance, and are therefore used in a variety of fields including electrical equipment, automobiles, housing equipment, and medical devices.

[0003] Furthermore, when glass fibers are incorporated into polypropylene resins, there is a known method of using acid-modified polypropylene obtained by grafting an acid-modified monomer such as maleic anhydride onto the polypropylene resin to improve the dispersibility of the glass fibers in the polypropylene resin and the adhesion between the polypropylene resin and the glass fibers, thereby improving the mechanical properties of the resulting molded article.

[0004] Furthermore, molded articles made of glass fiber-reinforced polypropylene resin containing a flame retardant are expected to be used in a wide range of applications requiring flame retardancy. However, such molded articles sometimes have inclusions such as glass fiber and flame retardant on the surface of the molded article, making them less attractive for commercial purposes. Therefore, improvements are needed.

[0005] Patent Document 1 discloses a reinforced polypropylene resin composition in which glass fiber, a flame retardant, and acid-modified polypropylene are blended into a polypropylene resin. The purpose of the invention is to provide a molded article thereof that complies with UL94 V-0, maintains high mechanical properties, and has little warpage.

[0006] Patent Document 2 discloses a reinforced polypropylene resin composition in which glass fiber, two flame retardants, and maleic anhydride-modified polypropylene are blended into a polypropylene resin. The purpose of the invention is to provide a resin composition having excellent flame retardancy, mechanical properties, and fluidity.

[0007] However, none of the patent documents discloses the commercial value of the surface and appearance of the molded article.

[0008] Prior art literature

[0009] Patent Literature

[0010] Patent Document 1: WO2022 / 189647

[0011] Patent Document 2: WO2020 / 064752 Summary of the Invention

[0012] Problems to be solved by the invention

[0013] The present invention provides a molded article made of a reinforced polypropylene resin composition comprising a polypropylene resin blended with glass fiber, a flame retardant, and an acid-modified polypropylene resin, which maintains the flame retardancy and mechanical properties of the molded article and has a high commercial value in terms of appearance.

[0014] Technical solutions to problems

[0015] That is, the gist of the present invention is as follows.

[0016] (I) A reinforced polypropylene resin composition, characterized in that it comprises:

[0017] Polypropylene resin (A) 10-70 mass%,

[0018] 15-40% by mass of phosphorus-based flame retardant (B), and

[0019] Glass fiber (C) 15-60% by mass

[0020] The total weight of the polypropylene resin (A), the phosphorus-based flame retardant (B) and the glass fiber (C) is 100% by mass.

[0021] The polypropylene resin (A) comprises:

[0022] An unmodified polypropylene resin (A-1) having an MFR of 100 to 400 g / 10 min at 230°C and a load of 2.16 kg, and

[0023] An acid-modified polypropylene resin (A-2) having an MFR of 100 to 1000 g / 10 minutes at 190°C and a load of 2.16 kg, a grafting amount of the acid-modified monomer of 0.5 to 3.0 mass %, and a grafting efficiency of the acid-modified monomer exceeding 60%.

[0024] (II) The reinforced polypropylene resin composition according to (I), comprising:

[0025] Polypropylene resin (A) 20-60 mass%,

[0026] 20-35% by mass of phosphorus-based flame retardant (B), and

[0027] Glass fiber (C) 20-50% by mass,

[0028] The total amount of the polypropylene resin (A), the phosphorus-based flame retardant (B), and the glass fiber (C) is 100% by mass.

[0029] (III) The reinforced polypropylene resin composition according to (I) or (II), wherein the acid-modified polypropylene resin (A-2) has a melting point of 150 to 170°C.

[0030] (IV) The reinforced polypropylene resin composition according to any one of (I) to (III), wherein the polypropylene resin (A) contains the acid-modified polypropylene resin (A-2) in a ratio of 0.1 to 3% by mass.

[0031] (V) The reinforced polypropylene resin composition according to any one of (I) to (IV), wherein the phosphorus-based flame retardant (B) is a phosphate compound.

[0032] (VI) The reinforced polypropylene resin composition according to any one of (I) to (V), further comprising 0.1 to 2 parts by mass of carbon black per 100 parts by mass of the total of the polypropylene resin (A), the phosphorus-based flame retardant (B) and the glass fiber (C).

[0033] (VII) A molded article comprising the reinforced polypropylene resin composition according to any one of (I) to (VI).

[0034] Effects of the Invention

[0035] The present invention can provide a molded article produced from a reinforced polypropylene resin composition comprising a polypropylene resin blended with glass fiber, a flame retardant, and an acid-modified polypropylene resin, which maintains the flame retardancy and mechanical properties of the molded article and has a high commercial value in terms of appearance. DETAILED DESCRIPTION

[0036] The polypropylene resin (A), the phosphorus-based flame retardant (B), and the glass fiber (C) constituting the reinforced polypropylene resin composition of the present invention are described below.

[0037] <Polypropylene resin (A)>

[0038] The polypropylene resin (A) contains an unmodified polypropylene resin (A-1) and an acid-modified polypropylene resin (A-2).

[0039] <Unmodified polypropylene resin (A-1)>

[0040] Unmodified polypropylene resin (A-1) (sometimes referred to as unmodified PP (A-1)) includes polypropylene homopolymers, copolymers of propylene with α-olefins such as ethylene and butene, and the like. Examples of copolymers include random copolymers or block copolymers of propylene with at least one α-olefin selected from ethylene and α-olefins having 4 to 20 carbon atoms. The content of the propylene backbone in the random copolymer is generally 90 to 99 mol%, preferably 92 to 98 mol%. The content of the propylene backbone in the block copolymer is generally 70 to 99 mol%, preferably 75 to 98 mol%. As the unmodified polypropylene resin (A-1), two or more polypropylene-based resins (e.g., a polypropylene homopolymer and a propylene-based copolymer) may be used in combination.

[0041] When the unmodified polypropylene resin (A-1) contains a propylene copolymer, specific examples of monomers other than propylene used in the propylene copolymer include ethylene, 1-butene, 2-methyl-1-propylene, 2-methyl-1-butene, 3-methyl-1-butene, 1-pentene, 1-hexene, 2-ethyl-1-butene, 2,3-dimethyl-1-butene, 2-methyl-1-pentene, 3-methyl-1-pentene, 4-methyl-1-pentene, 3-hexene, 2-ethyl-1-butene. ,3-dimethyl-1-butene, 1-heptene, methyl-1-hexene, dimethyl-1-pentene, ethyl-1-pentene, trimethyl-1-butene, methylethyl-1-butene, 1-octene, methyl-1-pentene, ethyl-1-hexene, dimethyl-1-hexene, propyl-1-heptene, methylethyl-1-heptene, trimethyl-1-pentene, propyl-1-pentene, diethyl-1-butene, 1-nonene, 1-decene, 1-undecene, 1-dodecene.

[0042] Propylene monomer derived from biomass or from chemical recycling

[0043] The unmodified polypropylene resin (A-1) may contain biomass-derived propylene as a monomer constituting the polymer. The propylene constituting the polymer may contain only biomass-derived propylene or both biomass-derived propylene and fossil fuel-derived propylene. Biomass-derived propylene refers to propylene formed from all renewable natural raw materials, including fungi, yeast, algae, and bacteria, derived from plants or animals, and their residues, as carbon, with a carbon content of 10 ﹣12 The ratio of about 14 C isotope, the biomass carbon concentration (pMC) measured according to ASTM D 6866 is around 100 (pMC).

[0044] In addition, the unmodified polypropylene resin (A-1) may also contain chemically recovered propylene as a monomer constituting the polymer. The propylene constituting the polymer may contain only chemically recovered propylene, or may contain chemically recovered propylene and propylene derived from fossil fuels and / or biomass. Chemically recovered propylene can be obtained by conventional methods.

[0045] The melt flow rate (MFR) of the unmodified polypropylene resin (A-1), measured at 230°C and a load of 2.16 kg according to ASTM D1238, is 100 to 400 g / 10 min, preferably 150 to 350 g / 10 min, more preferably 200 to 300 g / 10 min.

[0046] When the melt flow rate (MFR) is less than 100, the dispersion of the glass fiber and flame retardant deteriorates, resulting in reduced strength and poor appearance of the molded article obtained from the reinforced polypropylene resin composition, and thus a product with high commercial value cannot be obtained. When the melt flow rate (MFR) exceeds 400, the toughness of the reinforced polypropylene resin composition decreases, and pelletization during production may be impossible. When the MFR of the unmodified PP (A-1) is within the range of the present invention, the flame retardancy, strength such as impact strength, and appearance are also excellent. Although the reason for this is not yet determined, the inventors of the present invention speculate that this is due to improved impregnation of the glass fiber and flame retardant, resulting in improved dispersibility in the unmodified PP. The inventors of the present invention have also discovered that when the MFR of the unmodified PP is within the range of the present invention, even when the flame retardant (B) is added to the system of unmodified PP (A-1) / modified PP (A-2) / glass fiber (C), the Charpy impact performance tends to be maintained (or less likely to be reduced).

[0047] Furthermore, when the MFR of the unmodified polypropylene resin (A-1) is within this range, it can be molded and processed at a low temperature, and thus flame retardancy can be easily maintained during recycling or reuse, which is advantageous.

[0048] The unmodified polypropylene resin (A-1) is preferably an isotactic polypropylene resin. An isotactic polypropylene resin refers to a polypropylene resin having an isotactic pentad fraction as determined by NMR of 0.9 or greater, preferably 0.95 or greater. The unmodified polypropylene resin (A-1) is typically produced using a Ziegler-Natta catalyst, a metallocene catalyst, or the like.

[0049] <Acid-modified polypropylene resin (A-2)>

[0050] The acid-modified polypropylene resin (A-2) used in the present invention (sometimes referred to as modified PP (A-2)) is a resin obtained by reacting an acid-modified monomer with a polypropylene resin, and has a monomer unit derived from the acid-modified monomer in the molecule.

[0051] Examples of the polypropylene resin used for acid modification include the polymers exemplified as the unmodified polypropylene resin (A-1). The melt flow rate (MFR) of the polypropylene resin used can be appropriately determined by considering that the average molecular weight of the resin polymer changes (usually decreases) due to the acid modification reaction.

[0052] Examples of the acid-modified monomer used for acid modification include unsaturated carboxylic acids such as maleic acid, fumaric acid, itaconic acid, acrylic acid, methacrylic acid, citraconic acid, crotonic acid, isocrotonic acid, endo-cis-bicyclo[2.2.1]hept-2,3-dicarboxylic acid (NADIC acid, trademark), and methyl-endo-cis-bicyclo[2.2.1]hept-5-ene-2,3-dicarboxylic acid (methylNADIC acid, trademark).

[0053] Examples of unsaturated carboxylic acid derivatives include anhydrides, ester compounds, amide compounds, imide compounds, and metal salts of unsaturated carboxylic acids. Specific examples of unsaturated carboxylic acid derivatives include maleic anhydride, itaconic anhydride, methyl acrylate, ethyl acrylate, butyl acrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate, 2-hydroxyethyl methacrylate, monoethyl maleate, diethyl maleate, monomethyl fumarate, dimethyl fumarate, acrylamide, methacrylamide, maleic acid monoamide, maleic acid diamide, fumaric acid monoamide, maleimide, n-butylmaleimide, and sodium methacrylate. Among these, maleic acid and acrylic acid are preferred as unsaturated carboxylic acids, and maleic anhydride and 2-hydroxyethyl methacrylate are preferred as unsaturated carboxylic acid derivatives.

[0054] Acid modification can be performed by conventionally known methods, for example, grafting an acid-modified monomer onto a polypropylene resin. Specifically, grafting an acid-modified monomer onto a polypropylene resin serving as a graft backbone in the presence of a radical polymerization initiator is an example.

[0055] As the grafting method, a conventionally known method can be used, and examples thereof include a melt-kneading method and a solution method.

[0056] When the acid modification is performed by a melt kneading method, for example, the polypropylene resin and the acid-modified monomer are kneaded together with a radical polymerization initiator in an extruder to graft-copolymerize the acid-modified monomer for modification.

[0057] Examples of the radical polymerization initiator include organic peroxides and azo compounds. Examples of the organic peroxide include benzoyl peroxide, 2,4-dichlorobenzoyl peroxide, m-trioyl peroxide, di-t-butyl peroxide, dicumyl peroxide, 2,5-dimethyl-2,5-di(t-butylperoxide)hexane, 2,5-dimethyl-2,5-di(t-butylperoxide)hexyne-3, lauroyl peroxide, t-butyl peroxyacetate, 2,5-dimethyl-2,5-di(benzoylperoxide)hexane, t-butyl peroxybenzoate, t-butyl peroxyisobutyrate, t-butyl peroxyphenylacetate, t-butyl peroxysec-octanoate, t-butyl peroxypivalate, cumyl peroxypivalate, and t-butyl peroxyethylacetate.

[0058] Examples of the azo compound include azoisobutyronitrile and dimethyl azoisobutyrate. One or more radical polymerization initiators may be used.

[0059] When acid modification is performed by a solution method, the polypropylene resin is suspended or dissolved in a solvent, and an acid-modified monomer and a radical polymerization initiator are added and mixed at a temperature of usually 80 to 200° C. to carry out graft polymerization.

[0060] Examples of solvents used in the solution method include aromatic hydrocarbon solvents such as toluene and xylene; aliphatic hydrocarbon solvents such as hexane, heptane, octane, and decane; alicyclic hydrocarbon solvents such as cyclohexane and methylcyclohexane; chlorinated hydrocarbon solvents such as trichloroethylene, perchloroethylene, dichloroethylene, dichloroethane, and chlorobenzene; aliphatic alcohol solvents such as ethanol and isopropyl alcohol; ketone solvents such as acetone, methyl isobutyl ketone, and methyl ethyl ketone; and ester solvents such as methyl acetate, ethyl acetate, and butyl acetate. One or more solvents may be used.

[0061] As specific examples of the radical polymerization initiator, the same peroxides as those described above can be used.

[0062] The melt flow rate (MFR) (190°C, 2.16 kg load) of the acid-modified polypropylene resin (A-2) is 100 to 1000 g / 10 min, preferably 100 to 750 g / 10 min, and particularly preferably 100 to 500 g / 10 min.

[0063] When the melt flow rate (MFR) of the acid-modified polypropylene resin (A-2) is less than 100, the appearance of a molded article obtained from the reinforced polypropylene resin composition cannot be considered satisfactory, and a product with high commercial value tends not to be obtained.

[0064] The graft amount of the acid-modified monomer in the acid-modified polypropylene resin (A-2) is 0.5 to 3.0% by mass, preferably 0.3 to 2.0% by mass, and particularly preferably 0.5 to 1.5% by mass.

[0065] The graft amount (mass %) of the acid-modified monomer is the ratio of the monomer derived from the acid-modified monomer in the acid-modified polypropylene resin (A-2), that is, the ratio of the monomer not removed by the solvent (reflecting the monomer chemically bonded to the main chain of the polypropylene resin) expressed as a ratio (mass %) in the acid-modified polypropylene resin (A-2).

[0066] For example, the acid-modified polypropylene resin (A-2) is completely dissolved in boiling p-xylene by heating. The p-xylene solution containing the acid-modified polypropylene resin (A-2) is cooled, and then acetone is added and stirred to precipitate a polymer. The precipitated polymer is filtered and dried to obtain a purified polymer. The proportion (mass %) of the monomer derived from the acid-modified monomer in the purified polymer is taken as the graft amount (mass %) of the acid-modified monomer.

[0067] The grafted amount (mass %) can be measured and calculated by infrared absorption spectroscopy, NMR spectroscopy, or the like.

[0068] The grafting efficiency (%) of the acid-modified monomer of the acid-modified polypropylene resin (A-2) when used to reinforce the polypropylene resin composition exceeds 60%.

[0069] That is, the grafting efficiency (%) of the acid-modified polypropylene resin (A-2) is a value measured when it is used to prepare a reinforced polypropylene resin composition, or a value measured when it is used as a component in molding a molded article of the reinforced polypropylene resin composition.

[0070] The grafting efficiency (%) is preferably more than 60%, and particularly preferably more than 65%.

[0071] When the grafting efficiency (%) of the acid-modified monomer of the acid-modified polypropylene resin (A-2) is less than 60%, the strength of the molded product obtained from the reinforced polypropylene resin composition is reduced and the appearance is not good enough, and there is a tendency that a product with high commercial value cannot be obtained.

[0072] The grafting efficiency (%) of the acid-modified monomer can be determined as follows.

[0073] That is, the mass X (g / 100 g of sample polymer) of the monomers derived from the acid-modified monomer contained in the acid-modified polypropylene resin (A-2) sample (including the monomers chemically bonded to the polymer main chain of the polypropylene resin and the monomers remaining in the resin that are not chemically bonded to the polymer main chain during the grafting reaction and are eluted with the solvent) is determined.

[0074] Then, the mass Y (g / 100 g of sample polymer) of the monomer derived from the acid-modified monomer that has not been removed by the solvent (reflecting the monomer chemically bonded to the polymer main chain) in the sample polymer after the operation of removing the acid-modified monomer from the acid-modified polypropylene resin (A-2) with a solvent is determined.

[0075] The grafting efficiency (%) is a value obtained from these by the following formula.

[0076] [Y / X]×100=grafting efficiency (%)

[0077] For example, when the acid-modified monomer is maleic anhydride, the mass X (g) of the acid-modified monomer contained in the acid-modified polypropylene resin (A-2) (including monomers derived from the acid-modified monomer chemically bonded to the polymer main chain and monomers remaining in the resin that are not chemically bonded to the polymer main chain and eluted with the solvent during the grafting reaction) can be determined by Fourier transform infrared spectroscopy (FT-IR) of a film formed by pressing the acid-modified polypropylene resin (A-2) based on the wavelength of 1780 cm ﹣1 、974cm ﹣1 The intensity ratio of the infrared absorption peak is calculated.

[0078] In addition, the mass Y (g) of the acid-modified monomer after the acid-modified monomer is removed from the acid-modified polypropylene resin (A-2) with a solvent, that is, the mass Y (g) of the acid-modified monomer that is not removed by the solvent (reflecting the monomer derived from the acid-modified monomer that is chemically bonded to the polymer main chain) can be determined as follows: about 2 g of the acid-modified polypropylene resin is collected, completely dissolved by heating in 500 ml of boiling p-xylene, cooled, and then added to 1200 ml of acetone. The precipitate is filtered to remove maleic anhydride that does not participate in the grafting reaction in the resin. A film is prepared from the polymer precipitate by pressing and the Fourier transform infrared spectroscopy (FT-IR) is also performed based on 1780 cm ﹣1 、974cm ﹣1 The intensity ratio of the infrared absorption peak is calculated.

[0079] The grafting efficiency (%) is a value obtained from these by the following formula.

[0080] [Y / X]×100=grafting efficiency (%)

[0081] Furthermore, the melting point of the acid-modified polypropylene resin (A-2) is preferably 150 to 170°C.

[0082] <Phosphorus flame retardant (B)>

[0083] Examples of the phosphorus-based flame retardant (B) include red phosphorus-based compounds, phosphate compounds, phosphate esters, phosphonates, and phosphazene compounds. Among them, phosphate compounds are preferred.

[0084] <Phosphate compounds>

[0085] Phosphate compounds include not only phosphates but also salts of polyphosphoric acids such as diphosphoric acid (pyrophosphoric acid) and triphosphoric acid, and salts of phosphorous acid, hypophosphorous acid, and the like.

[0086] Phosphate Examples of the salts of the various phosphoric acids include salts with ammonium and nitrogen-containing compounds such as piperazine and melamine.

[0087] Specific examples of these ammonium salts include ammonium phosphate, ammonium dihydrogen phosphate, and diammonium hydrogen phosphate.

[0088] Examples of the polyphosphate include ammonium polyphosphate and ammonium polyphosphate amide.

[0089] In the present invention, preferred among phosphates are salts of phosphoric acid, diphosphoric acid (pyrophosphoric acid), triphosphoric acid, etc., and nitrogen-containing compounds such as piperazine and melamine. Examples of such nitrogen-containing compounds are as follows.

[0090] Examples of the aliphatic diamine include N,N,N',N'-tetramethyldiaminomethane, ethylenediamine, N,N'-dimethylethylenediamine, N,N'-diethylethylenediamine, N,N,N',N'-tetramethylethylenediamine, N,N,N',N'-tetraethylethylenediamine, 1,2-propylenediamine, 1,3-propylenediamine, tetramethylenediamine, and pentamethylenediamine.

[0091] Examples of the piperazine ring-containing amine compound include piperazine, trans-2,5-dimethylpiperazine, and 4-bis(2-aminoethyl)piperazine.

[0092] Examples of the triazine ring-containing amine compound include melamine, acetoguanamine, benzoguanamine, acrylguanamine, 2,4-diamino-6-nonyl-1,3,5-triazine, and 2,4-diamino-6-hydroxy-1,3,5-triazine.

[0093] Among them, salts of nitrogen-containing compounds such as piperazine and melamine are suitable, and at least one compound selected from piperazine phosphate, piperazine pyrophosphate, and piperazine polyphosphate is preferred.

[0094] <Phosphazene Compounds>

[0095] Examples of the phosphazene compound include phenoxyphosphazene, (poly)tolyloxyphosphazene (e.g., o-tolyloxyphosphazene, o-p-tolyloxyphosphazene, etc.), (poly)xylyloxyphosphazene, (poly)phenoxytolyloxyphosphazene (e.g., phenoxyo-tolyloxyphosphazene, phenoxym-tolyloxyphosphazene, etc.), (poly)phenoxyxylyloxyphosphazene, and (poly)phenoxytolyloxyxyloxyphosphazene.

[0096] The content of the phosphorus-based flame retardant (B) in the reinforced polypropylene resin composition is 15 to 40% by mass.

[0097] (The total amount of the polypropylene resin (A), the phosphorus-based flame retardant (B), and the glass fiber (C) is 100% by mass.)

[0098] The content of the phosphorus-based flame retardant (B) is preferably within a range of 20 to 35% by mass.

[0099] When the phosphorus-based flame retardant (B) is too low, the molded article of the reinforced polypropylene resin cannot obtain appropriate flame retardancy, while when the amount of the phosphorus-based flame retardant (B) is too high, the molded article tends to fail to obtain sufficient commercial value in terms of appearance.

[0100] Furthermore, since the phosphorus-based flame retardant is a halogen-free flame retardant, it is also excellent in environmental suitability.

[0101] <Glass Fiber (C)>

[0102] The type of glass fiber (C) is not particularly limited and may be any of E glass, S glass, C glass, and A glass. The fiber diameter is also not particularly limited and is usually 5 to 25 μm, preferably 6 to 20 μm.

[0103] The glass fiber (C) is preferably in the form of chopped strands. Typically, the chopped strands have a length of 1.5 to 10 mm and a fiber diameter of 5 to 25 μm, preferably 3 to 6 mm in length and 6 to 17 μm in diameter. Alternatively, continuous fiber bundles may be used. Continuous fiber bundles are commercially available, for example, as rovings. Their fiber diameters are typically 5 to 25 μm, preferably 10 to 20 μm.

[0104] While the glass fiber (C) can be used as is, it is preferably surface-treated with a treatment agent such as an organic titanate coupling agent, an organic silane coupling agent, a modified polyolefin grafted with an unsaturated carboxylic acid or its anhydride, a fatty acid, a fatty acid metal salt, or a fatty acid ester. More preferably, the compound used in the surface treatment agent contains an amino group. Alternatively, the surface may be treated with a thermosetting or thermoplastic resin component.

[0105] The reinforced polypropylene resin composition of the present invention may be formulated with additives such as other resins, heat stabilizers, antistatic agents, weathering stabilizers, light stabilizers, anti-aging agents, antioxidants, anti-copper aging agents, fatty acid metal salts, softeners, dispersants, fillers, colorants, pigments, and foaming agents as needed, within the scope of not impairing the purpose of the present invention. The additives may be mixed in any order, and may be mixed simultaneously or in a multi-step mixing method in which a portion of the components are mixed and then the remaining components are mixed. Among these, carbon black, phenolic antioxidants, and / or sulfur-based antioxidants are preferably formulated.

[0106] The reinforced polypropylene resin composition of the present invention preferably contains 0.1 to 2 parts by mass of carbon black based on 100 parts by mass of the total of the polypropylene resin (A), the phosphorus flame retardant (B) and the glass fiber (C).

[0107] <Reinforced Polypropylene Resin Composition>

[0108] The reinforced polypropylene resin composition of the present invention comprises the following composition:

[0109] Polypropylene resin (A) 10-70 mass%,

[0110] 15-40% by mass of phosphorus-based flame retardant (B), and

[0111] Glass fiber (C) 15 to 60 mass %.

[0112] Among them, preferably its composition is:

[0113] Polypropylene resin (A) 20-60 mass%,

[0114] 20-35% by mass of phosphorus-based flame retardant (B), and

[0115] Glass fiber (C) 20 to 50 mass %.

[0116] More preferably:

[0117] Polypropylene resin (A) 23-49 mass%,

[0118] Phosphorus flame retardant (B) 20-32 mass%,

[0119] Glass fiber (C) 25-45 mass %.

[0120] Within this range, the effect of adding the polypropylene resin (A) component is particularly significant.

[0121] (The total amount of the polypropylene resin (A), the phosphorus-based flame retardant (B), and the glass fiber (C) is 100% by mass.)

[0122] The reinforced polypropylene resin composition preferably contains the acid-modified polypropylene resin (A-2) in a ratio of 0.1 to 3% by mass, and more preferably in a ratio of 0.5 to 2% by mass.

[0123] (The total amount of the unmodified polypropylene resin (A-1), the acid-modified polypropylene resin (A-2), the phosphorus-based flame retardant (B), and the glass fiber (C) is 100% by mass.)

[0124] <Preparation of Reinforced Polypropylene Resin Composition>

[0125] The reinforced polypropylene resin composition of the present invention has high impact resistance and can be made into pellets, which can be short glass fiber pellets containing short fibers as glass fibers (C) or long glass fiber pellets containing long fibers as glass fibers (C).

[0126] The reinforced polypropylene resin composition of the present invention can be produced by melt-kneading a polypropylene resin (A), a phosphorus-based flame retardant (B), glass fibers (C), and, if necessary, other components. The melt-kneading temperature is, for example, 5 to 100°C higher than the melting temperature of the polymer components, and preferably 10 to 60°C higher than the melting point of the polymer with the highest melting point among the polymer components. The melt-kneading treatment time is, for example, 30 seconds to 15 minutes, preferably 1 to 10 minutes.

[0127] When the glass fiber (C) of the reinforced polypropylene resin composition of the present invention is a short fiber, it can be produced by fully melt-mixing and dispersing the various components in an extruder, etc. using a roll mill, Banbury mixer, kneader, etc. It is also possible to dry-blend using a drum blender, Henschel mixer, ribbon mixer, etc., and melt-mix using a single-screw extruder, twin-screw extruder, etc. to form a pelletized molding material. In this method, the glass fiber (C) can be added from either the top or side of the extruder. In addition, in this method, all or part of the various components other than the glass fiber (C) can also be melt-mixed separately and then melt-mixed with the glass fiber (C).

[0128] The reinforced polypropylene resin composition of the present invention can be processed into a molded body by conventional molding methods such as injection molding, extrusion molding, and compression molding. In the case of injection molding, for example, the above-mentioned short glass fiber pellets or long glass fiber pellets can be used for injection molding. In this case, when the short glass fiber pellets or long glass fiber pellets are added from the hopper of the injection molding machine, other resins can also be added. In addition, the short glass fiber pellets or long glass fiber pellets can also be side-fed from the vent of the injection molding machine, and other resins can be added from the hopper to mix and shape in the injection molding machine.

[0129] Alternatively, the polypropylene resin (A) may be melt-kneaded in an injection molding machine to form the product without passing through the short glass fiber pellets or long glass fiber pellets. In this case, the glass fiber (C) may be fed from the hopper of the injection molding machine or from the side through a vent or the like.

[0130] The entire molded article may be formed from the reinforced polypropylene resin composition of the present invention, or a portion of the molded article may include a portion formed from the reinforced polypropylene resin composition of the present invention. The molded article can be used in a wide range of applications, from household goods such as daily necessities and entertainment products to general industrial applications and industrial products. Examples include household appliance parts, communication equipment parts, electrical components, electronic components, automotive parts, parts for vehicles other than automobiles, ships and aircraft materials, mechanical parts, building materials, civil engineering parts, agricultural materials, power tool parts, food containers, films, sheets, and fibers.

[0131] Examples of home appliance parts, communication equipment parts, electrical parts, and electronic parts include battery pack parts (covers, trays, module cases), printers, computers, word processors, keyboards, small information terminals (PDAs), portable music players, mobile phones, telephones, fax machines, copiers, cards, stands, stationery, and other office / OA equipment; and home appliances such as washing machines, refrigerators, vacuum cleaners, microwave ovens, lighting fixtures, and game consoles.

[0132] Example

[0133] Hereinafter, the present invention will be described in more detail based on Examples and Comparative Examples.

[0134] However, the present invention is not limited to these Examples.

[0135] The measurement methods and evaluation methods related to the compositions used in Examples and Comparative Examples are as follows.

[0136] (1) Melt flow rate (MFR) (g / 10 min)

[0137] The melt flow rate (MFR) of the unmodified polypropylene resin (A-1) was measured at 230°C and under a load of 2.16 kg in accordance with ISO 1133.

[0138] The melt flow rate (MFR) of the acid-modified polypropylene resin (A-2) was measured at 190° C. and a load of 2.16 kg in accordance with ISO 1133.

[0139] (2a) Grafting amount of maleic anhydride (mass %)

[0140] About 2 g of the acid-modified polypropylene resin modified with maleic anhydride was collected and completely dissolved in 500 ml of boiling p-xylene by heating.

[0141] After cooling, the mixture was poured into 1200 ml of acetone, and the polymer precipitate was filtered and dried to obtain a purified polymer, which was then hot-pressed into a film having a thickness of 20 μm.

[0142] The infrared absorption spectrum of the prepared film was measured at 1780 cm ﹣1 The absorption near the pore size was used to quantify the grafting amount of maleic anhydride.

[0143] (2b) Grafting efficiency of maleic anhydride (%)

[0144] The mass X (g / 100 g of sample polymer) of the acid-modified monomer contained in the acid-modified polypropylene resin (A-2) is determined by pressing a sample polymer of the acid-modified polypropylene resin (A-2) used for the reinforced polypropylene resin of the present invention into a film and analyzing the film by Fourier transform infrared spectroscopy (FT-IR) at 1780 cm ﹣1 、974cm ﹣1 The intensity ratio of the infrared absorption peak is calculated.

[0145] In addition, the mass Y (g / 100g of sample polymer) of the acid-modified monomer of the sample polymer after the acid-modified monomer is removed with a solvent from the acid-modified polypropylene resin (A-2) used in the reinforced polypropylene resin of the present invention is determined as follows: about 2g of the acid-modified polypropylene resin is collected, completely dissolved by heating in 500ml of boiling p-xylene, cooled, and then added to 1200ml of acetone. The precipitate is filtered to remove maleic anhydride that has not participated in the grafting reaction in the resin. The polymer precipitate is pressed into a film, and Fourier transform infrared spectroscopy (FT-IR) is similarly used to analyze the molecular weight of the sample polymer based on the wavelength of 1780cm ﹣1 、974cm ﹣1 The intensity ratio of the infrared absorption peak is calculated.

[0146] The grafting efficiency (%) was determined from these by the following formula.

[0147] [Y / X]×100=grafting efficiency (%)

[0148] (3) Tensile breaking stress (MPa)

[0149] The samples were molded into ISO 1A dumbbells using a FANUC α-100iA injection molding machine at a barrel temperature of 220°C and a mold temperature of 40°C. The tensile stress at break was measured in accordance with ISO 527 at a tensile speed of 5 mm / min.

[0150] (4) Charpy impact strength (kJ / m 2 )

[0151] ISO 1A dumbbell pieces were molded using a FANUC α-100iA injection molding machine at a barrel temperature of 220°C and a mold temperature of 40°C, and the Charpy impact strength was measured in accordance with ISO 179.

[0152] (5) Flame retardancy UL94-V

[0153] Test pieces with a thickness of 1.6 mm were molded using a FANUC α-100iA injection molding machine at a cylinder temperature of 220°C and a mold temperature of 40°C. Flame retardancy was evaluated according to the UL94-V standard. If the test piece failed to meet the UL94-V standard, it was marked "Not Suitable." The total burning time (sec) was measured as the total burning time.

[0154] (6) Appearance of the test piece

[0155] ISO 1A dumbbell pieces were molded using an injection molding machine FANUC α-100iA at a barrel temperature of 220°C and a mold temperature of 40°C, and the surface appearance of the dumbbell pieces was visually evaluated.

[0156] The cases where the flame retardant and / or glass fiber were uniformly dispersed and had a good appearance were recorded as “○”;

[0157] The case where the flame retardant and / or glass fiber were unevenly dispersed and had a mottled appearance was marked as "×".

[0158] The components used in Examples and Comparative Examples are shown below.

[0159] <Polypropylene resin (A)>

[0160] <Unmodified polypropylene resin (A-1)>

[0161] (A-1-1): A polypropylene homopolymer manufactured by Prime Polymer Co., Ltd., having an MFR of 200 g / 10 min as measured at 230°C and a load of 2.16 kg.

[0162] (A-1-2) Polypropylene homopolymer manufactured by Prime Polymer Co., Ltd., having an MFR of 30 g / 10 min as measured at 230°C and a load of 2.16 kg.

[0163] (A-1-3) Polypropylene homopolymer manufactured by Primen Polymer Co., Ltd., having an MFR of 500 g / 10 min as measured at 230°C and a load of 2.16 kg.

[0164] (A-1-4) Polypropylene homopolymer manufactured by Prime Polymer Co., Ltd., having an MFR of 60 g / 10 min as measured at 230°C and a load of 2.16 kg.

[0165] (A-1-5) A propylene-ethylene block copolymer manufactured by Primen Polymer Co., Ltd. having an MFR of 90 g / 10 min as measured at 230°C and a load of 2.16 kg.

[0166] <Acid-modified polypropylene resin (A-2)>

[0167] (A-2-1) Maleic anhydride-modified polypropylene manufactured by Polymer Asia Co., Ltd., having an MFR of 180 g / 10 min as measured at 190°C and a load of 2.16 kg, a melting point of 158°C as measured by differential scanning calorimetry, and a maleic anhydride grafting amount of 0.7% by mass (trade name: PA-Bond 700ZV).

[0168] (A-2-2) Maleic anhydride-modified polypropylene manufactured by SI Corporation (trade name: Polybond 3200), having an MFR of 110 g / 10 min as measured at 190°C and a load of 2.16 kg, a melting point of 158°C as measured by a differential scanning calorimeter, and a maleic anhydride grafting amount of 0.5% by mass.

[0169] (A-2-3) Maleic anhydride-modified polypropylene manufactured by Primen Polymer Co., Ltd., having an MFR of 30 g / 10 min as measured at 190°C and a load of 2.16 kg, a melting point of 156°C as measured by a differential scanning calorimeter, and a maleic anhydride grafting amount of 0.3% by mass (trade name: ZP648).

[0170] (A-2-4) Maleic anhydride-modified polypropylene manufactured by The Dow Chemical Company, having an MFR of 400 g / 10 min as measured at 190°C and a load of 2.16 kg, a melting point of 134°C as measured by differential scanning calorimetry, and a maleic anhydride grafting amount of 0.9 mass% (trade name: Fusabond P353)

[0171] <Phosphorus flame retardant (B)>

[0172] “FP-2300S”: A phosphate-based flame retardant containing piperazine phosphate as a main component (manufactured by ADEKA Corporation, trade name: FP-2300S).

[0173] <Glass Fiber (C)>

[0174] “T-480”: Glass fiber (manufactured by Nippon Electric Glass Co., Ltd., trade name: T-480).

[0175] <Carbon Black Masterbatch>

[0176] "PPM01143": Polypropylene as the carrier resin, containing 30% by mass of carbon black.

[0177] (Toyochem Co., Ltd., trade name: PPM01143)

[0178] "PPM0127A": Polypropylene as the carrier resin, containing 40% by mass of carbon black.

[0179] (Manufactured by Toyochem Co., Ltd., trade name: PPM0127A)

[0180] <Antioxidants>

[0181] “Irg1010”: a phenolic antioxidant (manufactured by BASF, trade name: Irganox (registered trademark) 1010).

[0182] “DMTP”: Sulfur-based antioxidant (manufactured by Mitsubishi Chemical Corporation, trade name: DMTP).

[0183] Examples 1 to 8 and Comparative Examples 1 to 5

[0184] The unmodified polypropylene resin (A-1), acid-modified polypropylene resin (A-2), phosphorus-based flame retardant (B), carbon black masterbatch, and other components shown in Table 1 were uniformly mixed in a drum mixer, and the mixture was fed to a co-rotating twin-screw kneader (TEX (registered trademark) 30α manufactured by The Nippon Steel Works, Ltd.). Next, glass fiber (C) was side-fed into the twin-screw kneader midway, and the mixture was heated and kneaded at 210°C to obtain pellets of a fiber-reinforced reinforced polypropylene resin composition.

[0185] Each pellet was molded into an ISO No. 1 dumbbell test piece using an injection molding machine (FANUC) at a molding temperature of 220° C. and a mold temperature of 40° C. The tensile breaking stress and Charpy impact strength were measured using the test piece. The results are shown in Table 1.

[0186] The mixing ratio of the carbon black masterbatch and the antioxidant is expressed as a mixing ratio (phr) relative to 100 parts by mass of the total of the unmodified polypropylene resin (A-1), the acid-modified polypropylene resin (A-2), the phosphorus-based flame retardant (B) and the glass fiber (C).

[0187] The amount of carbon black is expressed as a blending ratio (phr) relative to 100 parts by mass of the total of the polypropylene resin (A), the phosphorus-based flame retardant (B), and the glass fiber (C).

[0188] [Table 1]

[0189]

[0190] Industrial applicability

[0191] The glass fiber-reinforced polypropylene resin composition of the present invention can be suitably used as a material for molded articles having excellent appearance, high commercial value, and excellent mechanical properties under high-temperature and high-humidity environments in various fields.

Claims

1. A reinforced polypropylene resin composition, characterized in that Include: Polypropylene resin (A) 10-70 mass%, 15-40% by mass of phosphorus-based flame retardant (B), and Glass fiber (C) 15-60% by mass The total weight of the polypropylene resin (A), the phosphorus-based flame retardant (B) and the glass fiber (C) is 100% by mass. The polypropylene resin (A) comprises: An unmodified polypropylene resin (A-1) having an MFR of 100 to 400 g / 10 min at 230°C and a load of 2.16 kg, and An acid-modified polypropylene resin (A-2) having an MFR of 100 to 1000 g / 10 minutes at 190°C and a load of 2.16 kg, a grafting amount of an acid-modified monomer of 0.5 to 3.0 mass %, and a grafting efficiency of the acid-modified monomer exceeding 60%.

2. The reinforced polypropylene resin composition according to claim 1, wherein Include: Polypropylene resin (A) 20-60 mass%, 20-35% by mass of phosphorus-based flame retardant (B), and Glass fiber (C) 20-50% by mass, The total amount of the polypropylene resin (A), the phosphorus-based flame retardant (B), and the glass fiber (C) is 100% by mass.

3. The reinforced polypropylene resin composition according to claim 1, wherein: The melting point of the acid-modified polypropylene resin (A-2) is 150 to 170°C.

4. The reinforced polypropylene resin composition according to claim 1, wherein: The polypropylene resin (A) contains the acid-modified polypropylene resin (A-2) in a ratio of 0.1 to 3% by mass.

5. The reinforced polypropylene resin composition according to claim 1, wherein: The phosphorus-based flame retardant (B) is a phosphate compound.

6. The reinforced polypropylene resin composition according to claim 1, wherein: The reinforced polypropylene resin composition further contains 0.1 to 2 parts by mass of carbon black based on 100 parts by mass of the total of the polypropylene resin (A), the phosphorus-based flame retardant (B) and the glass fiber (C).

7. A molded body, characterized in that: The molded body is formed from the reinforced polypropylene resin composition according to claim 1.

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