Filler-containing polypropylene resin composition

Abstract

Provided is a polypropylene resin composition which achieves an excellent balance of rigidity and shock-resistance and comprises a propylene polymer composition comprising a filler, and comprises a polyamide resin and a modified elastomer.　Provided is a polypropylene resin composition containing a propylene polymer composition (a), a polyolefin composition (b), and an acid-modified polypropylene (c), wherein: the propylene polymer composition (a) comprises a propylene polymer (a1) and a filler (a2); the polyolefin composition (b) comprises a polyolefin (b1), an aliphatic polyamide resin (b2), and a modified elastomer (b3), and has a specific phase structure; and the modified elastomer (b3) is an elastomer in which a moiety comprising a group reactive with the aliphatic polyamide resin (b2) is added to a specific unmodified elastomer (b3').

Description

[Technical Field]

[0001] The present invention relates to a filler-containing propylene polymer composition and a polypropylene resin composition containing a polyamide resin. [Background technology]

[0002] Resin compositions containing a propylene polymer, a polyamide resin, and a modified elastomer having an acid group such as an acid anhydride group introduced therein, which acts as a compatibilizer, have been investigated as resins with improved impact resistance, and it has been revealed that a specific phase structure is formed (see, for example, Patent Documents 1 to 4). Furthermore, with the aim of improving impact resistance and rigidity, a resin composition containing a propylene-based polymer, a polyamide resin containing a filler (e.g., an inorganic filler, a natural fiber, etc.), and a modified elastomer having a group reactive with the polyamide resin has been investigated. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2013 / 094763 Brochure [Patent Document 2] International Publication No. 2013 / 094764 Brochure [Patent Document 3] International Publication No. 2018 / 139378 Brochure [Patent Document 4] International Publication No. 2018 / 135648 Brochure Summary of the Invention [Problem to be solved by the invention]

[0004]

[0005] For the purpose of further improving the physical properties (e.g., impact resistance) of a resin composition containing a propylene-based polymer, a polyamide resin, and a modified elastomer, it may be possible to consider a resin composition containing a filler, i.e., a propylene-based polymer composition containing a filler, a polyamide resin, and a modified elastomer. However, according to the studies of the present inventors, it was found that even a resin composition containing a filler-added propylene-based polymer, a polyamide resin, and a modified elastomer would significantly reduce rigidity, and it became clear that further improvement would be necessary for practical use.

[0005] An object of the present invention is to provide a propylene-based polymer composition containing a filler (e.g., inorganic filler, natural fiber, etc.), a polyamide resin, and a polypropylene resin composition containing a modified elastomer, which has an excellent balance between rigidity and impact resistance. [Means for solving the problem]

[0006] As a result of investigations conducted by the present inventors under these circumstances, they found that the above-mentioned problems can be solved by a propylene-based polymer composition having a specific phase structure, which comprises a propylene-based polymer composition containing a filler, a polyolefin composition containing a polyolefin, an aliphatic polyamide resin, and a modified elastomer, and further contains acid-modified propylene, and thus completed the present invention.

[0007] That is, the present invention relates to, for example, the following [1] to

[11] . [1] A polypropylene resin composition comprising a propylene polymer composition (a), a polyolefin composition (b), and an acid-modified polypropylene (c), The propylene polymer composition (a) contains a propylene polymer (a1) and a filler (a2), The polyolefin composition (b) comprises a polyolefin (b1), an aliphatic polyamide resin (b2), and a modified elastomer (b3), and A continuous phase (α) containing a polyolefin (b1) and a dispersed phase (β) containing an aliphatic polyamide resin (b2) and a modified elastomer (b3) dispersed in the continuous phase (α), the dispersed phase (β) is composed of a melt-kneaded mixture of the aliphatic polyamide resin (b2) and the modified elastomer (b3), the modified elastomer (b3) is an elastomer in which a moiety containing a group reactive with the aliphatic polyamide resin (b2) is added to an unmodified elastomer (b3'), and the unmodified elastomer (b3') is an olefin-based thermoplastic elastomer containing a structural unit derived from ethylene and a structural unit derived from an α-olefin having 3 to 8 carbon atoms, or a styrene-based thermoplastic elastomer containing a structural unit derived from a styrene-based compound; A polypropylene resin composition characterized in that the dispersed phase (β) accounts for 80% by mass or less when the total of the continuous phase (α) and the dispersed phase (β) is taken as 100% by mass. [2] The polypropylene resin composition according to [1], wherein the filler (a2) is an inorganic filler (a2-1). [3] The polypropylene resin composition according to [1], wherein the filler (a2) is a natural fiber (a2-2). [4] The polypropylene resin composition according to any one of [1] to [3], wherein the propylene polymer (a1) is a propylene-ethylene block copolymer having a dispersed phase of an ethylene polymer block. [5] The polypropylene resin composition according to [2] or [4], wherein the inorganic filler (a2-1) is one or more inorganic fillers selected from the group consisting of talc, mica, glass fiber, and calcium carbonate. [6] The polypropylene resin composition according to [3] or [4], wherein the natural fibers (a2-2) are one or more natural fibers selected from the group consisting of cellulose fibers, wood flour, and wood flour fibers. [7] The polypropylene resin composition according to any one of [1] to [6], wherein the polyolefin (b1) is a propylene homopolymer. [8] The polypropylene resin composition according to any one of [1] to [7], wherein the aliphatic polyamide resin (b2) is one or more aliphatic polyamide resins selected from the group consisting of polyamide 6, polyamide 11, polyamide 12, polyamide 612, polyamide 610, and polyamide 1010. [9] The polypropylene resin composition according to any one of [1] to [8], wherein the dispersed phase (β) has a continuous phase (β1) containing the aliphatic polyamide resin (b2) and a finely dispersed phase (β2) containing the modified elastomer (b3) dispersed in the continuous phase (β1).

[10] The polypropylene resin composition according to any one of [1] to [9], wherein the content of the propylene polymer composition (a) is 50 to 94.9 parts by mass, the content of the polyolefin composition (b) is 5 to 49.9 parts by mass, and the content of the modified polypropylene (c) is 0.1 to 15 parts by mass (wherein the total content of the propylene polymer composition (a), the polyolefin composition (b), and the modified polypropylene (c) is 100 parts by mass).

[11] The polypropylene resin composition according to any one of [1] to [9], wherein the content of the propylene polymer composition (a) is 50 to 94.9 parts by mass, the content of the polyolefin composition (b) is 5 to 49.9 parts by mass, and the content of the modified polypropylene (c) is 0.1 to 5 parts by mass (wherein the total content of the propylene polymer composition (a), the polyolefin composition (b), and the modified polypropylene (c) is 100 parts by mass). [Effects of the Invention]

[0008] According to the present invention, there is provided a polypropylene resin composition which has an excellent balance between rigidity and impact resistance and which comprises a propylene polymer composition containing a filler, a polyamide resin, and a modified elastomer. DETAILED DESCRIPTION OF THE INVENTION

[0009] The present invention will be described below. <Polypropylene resin composition> The polypropylene resin composition according to the present invention contains a propylene polymer composition (a), a polyolefin composition (b), and an acid-modified polypropylene (c).

[0010] <Propylene-Based Polymer Composition (a)> The propylene polymer composition (a) used in the present invention contains a propylene polymer (a1) and a filler (a2).

[0011] [Propylene polymer (a1)] The propylene polymer (a1) is not particularly limited as long as it contains structural units derived from propylene as the main component (typically containing more than 50 mol% of structural units derived from propylene), and may be a propylene homopolymer or a copolymer of propylene and an α-olefin other than propylene (hereinafter also referred to as "other α-olefin") (hereinafter also referred to as "propylene-α-olefin copolymer"). The propylene-α-olefin copolymer may be a propylene-α-olefin block copolymer or a propylene-α-olefin random copolymer.

[0012] Examples of the other α-olefins include ethylene and α-olefins having 4 to 20 carbon atoms, such as ethylene, 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene, 1-eicosene, 4-methyl-1-pentene, 2-methyl-1-butene, 3-methyl-1-butene, 3-methyl-1-butene, 3,3-dimethyl-1-butene, 3-methyl-1-pentene, 3-methyl-1-hexene, and 3,5,5-trimethyl-1-hexene. Among these, the other α-olefins are preferably ethylene and 1-butene, and more preferably ethylene.

[0013] Suitable specific examples of the propylene-α-olefin copolymer include a propylene-ethylene copolymer and a propylene-1-butene copolymer, with a propylene-ethylene copolymer being preferred.

[0014] From the viewpoint of obtaining a polypropylene resin composition with a better balance between rigidity and impact resistance, the propylene polymer (a1) is preferably a propylene-ethylene block copolymer having a dispersed phase of an ethylene polymer block. The monomers used as raw materials for the propylene polymer (a1) may be, for example, monomers derived from fossil fuels, monomers derived from biomass, or a combination of monomers derived from fossil fuels and monomers derived from biomass. These monomers may be used alone or in combination of two or more.

[0015] The amount of the propylene polymer (a1) that is soluble in decane at room temperature (23° C.) is preferably 5% by mass to 30% by mass based on the total mass of the propylene polymer (a1). The room temperature (23°C) decane soluble fraction refers to a component soluble in n-decane at 23°C (hereinafter also referred to as "decane soluble fraction") when the propylene polymer (a1) is fractionated with n-decane solvent. The room temperature (23°C) decane insoluble fraction refers to a component insoluble in n-decane at 23°C (hereinafter also referred to as "decane insoluble fraction") when the propylene polymer (a1) is fractionated with n-decane solvent. The decane soluble content and the decane insoluble content are measured by the following method.

[0016] (Ratio of n-decane soluble (insoluble) components at 23°C) Approximately 3 g of a propylene polymer, 500 ml of n-decane, and a small amount of a heat-resistant stabilizer soluble in n-decane were placed in a glass measuring vessel, and the vessel was heated to 150°C over 2 hours while stirring with a stirrer under a nitrogen atmosphere to dissolve the propylene polymer. The vessel was then maintained at 150°C for 2 hours and then slowly cooled to 23°C over 8 hours. The resulting liquid containing a precipitate of the propylene polymer was filtered under reduced pressure using a 25G-4 glass filter manufactured by Iwata Glass Co., Ltd. 100 ml of the filtrate was collected and dried under reduced pressure to obtain a portion of the n-decane-soluble component. After this operation, the proportion (mass%) of the n-decane-soluble component and the proportion (mass%) of the insoluble component at 23°C were determined using the following formula. The mass of the propylene polymer was 10 -4 The mass was measured to the unit of g, and this mass was expressed as b(g) in the following formula. -4 The mass was measured to the unit of g, and this mass was expressed as a(g) in the formula below. Proportion of n-decane soluble components at 23°C (mass%) = 100 × (500 × a) / (100 × b) Proportion of n-decane insoluble components at 23°C (mass%) = 100 - 100 × (500 × a) / (100 × b)

[0017] The amount of the decane-soluble portion is preferably 5 to 30 mass%, more preferably 7 to 25 mass%, and even more preferably 10 to 20 mass%, relative to the total mass of the propylene polymer (a1), and the amount of the decane-insoluble portion is preferably 70 to 95 mass%, more preferably 75 to 93 mass%, and even more preferably 80 to 90 mass%. When the contents of the decane-soluble and decane-insoluble parts are within the above ranges, molded articles (for example, automobile interior and exterior materials) formed from the composition have excellent mechanical properties such as rigidity and impact resistance.

[0018] When the propylene polymer (a1) is mainly a copolymer, the decane-soluble portion preferably comprises a propylene-α-olefin copolymer such as a propylene-ethylene random copolymer, and may also contain a portion of a propylene homopolymer, such as a by-product generated during polymerization of low molecular weight substances. When the propylene polymer (a1) is a copolymer of propylene and another α-olefin, the other α-olefin contained in the decane-soluble portion may be ethylene and / or an α-olefin having 4 to 12 carbon atoms. Specific examples of such other α-olefins include ethylene, 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 3-methyl-1-pentene, 1-heptene, 1-octene, 1-nonene, 1-decene, and 1-dodecene. Among these, ethylene is preferred as the other α-olefin.

[0019] The decane-insoluble portion usually consists only of structural units derived from propylene. However, when the propylene-based polymer (a1) is a copolymer of the above-mentioned propylene and other α-olefin, it may contain a small amount, for example, 10 mol % or less, preferably 5 mol % or less, of structural units derived from monomers other than propylene. Examples of the monomer other than propylene include α-olefins other than propylene, such as ethylene, 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 3-methyl-1-pentene, 1-heptene, 1-octene, 1-nonene, 1-decene, and 1-dodecene. Among these, ethylene and α-olefins having 4 to 10 carbon atoms are preferred. These may be copolymerized singly or in combination of two or more.

[0020] The intrinsic viscosity ([η]) of the decane-soluble portion of the propylene polymer (a1) measured in decalin at 135°C is preferably 0.1 to 10.0 dl / g, more preferably 1.0 to 9.8 dl / g, even more preferably 1.5 to 9.5 dl / g, and particularly preferably 2.0 to 9.0 dl / g.

[0021] When the intrinsic viscosity ([η]) of the decane-soluble portion is within the above range, the automobile interior and exterior materials formed from the composition have an excellent balance between rigidity and impact resistance. When further mechanical properties are required for the automobile interior and exterior materials formed from the composition, the intrinsic viscosity ([η]) of the decane-soluble portion is preferably 4.0 to 9.0 dl / g, more preferably 4.5 to 8.7 dl / g, and even more preferably 5.0 to 8.4 dl / g.

[0022] The MFR (ASTM D1238, 230° C., 2.16 kg load) of the propylene polymer (a1) is preferably 1 to 200 g / 10 min, more preferably 10 to 100 g / 10 min, and even more preferably 20 to 70 g / 10 min. When the propylene polymer (a1) having an MFR within the above range is used, the resulting polypropylene resin composition has a better balance between fluidity and impact resistance.

[0023] [Filler (a2)] The filler (a2) is not particularly limited, and various conventionally known inorganic fillers (a2-1) and natural fibers (a2-2) can be used without restriction as long as the effects of the present invention are not impaired. The inorganic filler (a2-1) is not particularly limited as long as it is a filler made of an inorganic compound, and for example, known fillers can be used. Examples of the inorganic filler (a2-1) include carbon black or carbon black surface-treated with graphite or a silane coupling agent; oxide-based fillers including finely powdered silicic acid, silica (including fumed silica, precipitated silica, diatomaceous earth, and quartz), alumina, iron oxide, ferrite, magnesium oxide, titanium oxide, antimony trioxide, zirconium oxide, barium oxide, and calcium oxide; hydroxide-based fillers including aluminum hydroxide and magnesium hydroxide; silicate-based fillers including aluminum silicate (clay), magnesium silicate (talc), mica, kaolin, calcium silicate, glass fiber, glass flakes, and glass beads; sedimentary rock-based fillers including diatomaceous earth and limestone; montmorillonite, magnesian montmorillonite, and tetsu-montmorillonite. Clay mineral-based fillers including arsenite, tetramagnesian montmorillonite, beidellite, aluminian beidellite, nontronite, aluminian nontronite, saponite, aluminian saponite, hectorite, sauconite, stevensite, and bentonite; magnetic-based fillers including ferrite, iron, and cobalt; conductive fillers including silver, gold, copper, and alloys thereof; thermally conductive fillers including aluminum nitride, boron nitride, and silicone carbide; sulfate-based fillers including aluminum sulfate, magnesium sulfate, barium sulfate, and calcium sulfate; sulfite-based fillers including calcium sulfite; carbonate-based fillers including calcium carbonate, basic magnesium carbonate, and dolomite; titanate-based fillers including barium titanate and potassium titanate; and the like.

[0024] From the viewpoint of obtaining a polypropylene resin composition with a better balance between rigidity and impact resistance, the inorganic filler (a2-1) is preferably talc, mica, glass fiber, or calcium carbonate, and more preferably talc.

[0025] These inorganic fillers (a2-1) may be used alone or in combination of two or more.

[0026] The particle size of the inorganic filler (a2-1) is preferably 0.01 μm to 100 μm, more preferably 0.1 μm to 80 μm, and even more preferably 1 μm to 50 μm, from the viewpoint of improving dispersibility in the propylene polymer composition (a). The particle size (average particle size) of the inorganic filler is the 50% particle size (d50) obtained from the cumulative % distribution curve measured with a laser diffraction particle size distribution analyzer.

[0027] The natural fiber (a2-2) is not particularly limited as long as it can be used as a filler, and known natural fibers can be used. Examples of natural fibers (a2-2) include wood flour (processed by peeling wood and grinding it), wood fiber, bamboo flour, bamboo fiber, isolated cellulose fiber, wool, agricultural fiber, wood pulp (pulp made from wood, obtained by removing the bark from the trunk of a tree and then chipping it, which is then subjected to mechanical, chemical, or combined processing), other natural pulps, rayon, cotton, etc. Examples of agricultural fibers include wheat straw, rice straw, hemp, flax, kenaf, kapok, jute, ramie, sisal, henequen, corn fiber, coir, nut shells, and rice husks. Examples of wood pulp include NBKP (softwood bleached kraft pulp) and LBKP (hardwood bleached kraft pulp). Examples of the other natural pulps include Manila hemp, paper mulberry, mitsumata, and gampi. Of these, wood flour, wood fiber, bamboo, bamboo fiber, cotton, and isolated cellulose fiber are preferred, and isolated cellulose fiber is more preferred from the viewpoints of suppressing variations in the mechanical strength of the molded body and improving the predictability of the strength of the obtained molded body.

[0028] The origin of the cellulose fibers is not particularly limited, and they may be cellulose fibers obtained from any material, such as wood, grass, pulp, and paper. Cellulose fibers obtained from trees may be cellulose fibers obtained from any woody raw material, including conifers and broad-leaved trees. Cellulose fibers obtained from grasses may be cellulose fibers obtained from non-woody raw materials, such as grasses, mallows, legumes, and palms. Cellulose fibers obtained from pulp may be cellulose fibers obtained from any pulp, such as cotton linter pulp obtained from the fibers surrounding cotton seeds. Cellulose fibers obtained from paper may be cellulose fibers obtained from any paper, such as newspaper, cardboard, magazines, and fine paper. Among these, cellulose fibers obtained from trees or grasses are preferred because they are easily available and inexpensive, and cellulose fibers obtained from trees are more preferred.

[0029] From the viewpoint of improving the mechanical strength and impact resistance of the resulting polypropylene resin composition, the cellulose fibers preferably have an average degree of polymerization of 50 or more and 2000 or less, and more preferably 100 or more and 1500 or less. The average degree of polymerization of the cellulose fibers can be measured according to the reduced specific viscosity method using a copper ethylenediamine solution described in Verification Test (3) of the "Commentary on the Japanese Pharmacopoeia, 15th Edition (published by Hirokawa Shoten)."

[0030] The cellulose fibers may be unmodified or unamorphized, or may be modified or amorphized. The modified cellulose fibers may be those obtained by reacting hydroxyl groups of cellulose with an ether compound, alkyl chloride, alkyl acid anhydride, alkyl acid chloride, or the like. The amorphized cellulose fibers may be those obtained by reducing the crystallinity of cellulose using a known method.

[0031] The cellulose fibers have hydroxyl groups, and polar functional groups such as hydroxyl groups, carboxyl groups, amino groups, and quaternary ammonium groups that have been introduced by modification.

[0032] Examples of commercially available cellulose fibers include KC Flock GK series cellulose fibers manufactured by Nippon Paper Industries Co., Ltd. ("KC Flock" is a registered trademark of the company).

[0033] These natural fibers (a2-2) may be used alone or in combination of two or more kinds.

[0034] The mass ratio of the propylene polymer (a1) to the filler (a2) contained in the propylene polymer composition (a) (mass of the propylene polymer (a1) / mass of the filler (a2), hereinafter simply referred to as "(a1) / (a2)") is preferably 65 / 35 to 99 / 1. In other words, in the propylene polymer composition (a) of the present invention, when the total amount of the propylene polymer (a1) and the filler (a2) is 100 parts by mass, the amount of the propylene polymer (a1) is 65 to 99 parts by mass, and the amount of the filler (a2) is 1 to 35 parts by mass.

[0035] From the viewpoint of more suitably achieving the effects of the present invention, the content of the propylene polymer (a1) in the propylene polymer composition (a) is preferably 70 parts by mass or more, more preferably 75 parts by mass or more, even more preferably 80 parts by mass or more, and is preferably 97 parts by mass or less, more preferably 95 parts by mass or less, and even more preferably 93 parts by mass or less. In particular, when the content of the propylene polymer (a1) in the propylene polymer composition (a) is within the above range, the rigidity of the resulting polypropylene resin composition is more likely to be improved, and a significant decrease in impact resistance is unlikely to occur.

[0036] The content of the filler (a2) in the propylene polymer composition (a) is preferably 3 parts by mass or more, more preferably 5 parts by mass or more, even more preferably 7 parts by mass or more, and is preferably 30 parts by mass or less, more preferably 25 parts by mass or less, even more preferably 20 parts by mass or less. When two or more kinds of propylene polymers (a1) are used, the total amount of the propylene polymers (a1) is the "content of the propylene polymer (a1)." When two or more kinds of fillers (a2) are used, the total amount of the fillers (a2) is the "content of the filler (a2)."

[0037] In addition to the propylene polymer (a1) and the filler (a2), the propylene polymer composition (a) may contain, as necessary, additives such as a heat stabilizer, an antistatic agent, a weather stabilizer, a light stabilizer, an antioxidant, an antioxidant, a fatty acid metal salt, a softener, a dispersant, a filler, a colorant, a lubricant, and a pigment, within the range that does not impair the effects of the present invention.

[0038] The propylene polymer composition (a) can be produced by mixing the above-mentioned components by a conventionally known method. For example, the propylene polymer (a1), the filler (a2), and optional additives can be mixed in a Henschel mixer, V-blender, ribbon blender, tumbler blender, or the like, and the resulting mixture can be melt-kneaded in an extruder to produce pellets of the propylene polymer composition (a).

[0039] <Polyolefin composition (b)> The polyolefin composition (b) used in the present invention contains a polyolefin (b1), an aliphatic polyamide resin (b2), and a modified elastomer (b3).

[0040] [Polyolefin (b1)] The polyolefin (b1) is a polymer mainly composed of an α-olefin, such as a homopolymer of an α-olefin (including ethylene), such as ethylene, propylene, 1-butene, or 4-methyl-1-pentene, a copolymer of the above α-olefin with another α-olefin, or a copolymer of the above α-olefin with a monomer other than an α-olefin. Specific examples of the polyolefin (b1) include the following ethylene polymers, propylene polymers, and 1-butene polymers.

[0041] <Ethylene-based polymer> The ethylene polymers are homopolymers of ethylene and copolymers of ethylene and α-olefins having 3 to 20 carbon atoms, and examples thereof include polymers that are generally called high-density polyethylene (HDPE), medium-density polyethylene (MDPE), low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE), and ethylene-α-olefin copolymers, and are composed primarily of structural units derived from ethylene (typically containing more than 50 mol% of structural units derived from ethylene). Specific examples of the α-olefin having 3 to 20 carbon atoms to be copolymerized with ethylene include α-olefins having 4 to 20 carbon atoms, such as propylene, 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene, 1-eicosene, 2-methyl-1-butene, 3-methyl-1-butene, 3,3-dimethyl-1-butene, 3-methyl-1-pentene, and 3-methyl-1-hexene. Among these, α-olefins having 3 to 10 carbon atoms are preferred, and α-olefins having 3 to 8 carbon atoms are more preferred, with ethylene, 1-butene, 1-hexene, 4-methyl-1-pentene, and 1-octene being even more preferred. The molar ratio of ethylene to α-olefin (ethylene / α-olefin) is preferably from 99 / 1 to 60 / 40, more preferably from 95 / 5 to 70 / 30, and even more preferably from 90 / 10 to 60 / 25.

[0042] Specific preferred examples of the ethylene-α-olefin copolymer include ethylene-propylene copolymer, ethylene-1-butene copolymer, ethylene-1-hexene copolymer, ethylene-4-methyl-1-pentene copolymer, ethylene-1-octene copolymer, and ethylene-propylene-1-butene copolymer.

[0043] <Propylene-based polymer> The propylene-based polymer is a polymer mainly composed of structural units derived from propylene (typically containing more than 50 mol% of structural units derived from propylene), such as a homopolymer of propylene (homo PP), a copolymer of propylene and ethylene and / or an α-olefin having 4 to 20 carbon atoms (random copolymer: random PP), or a composition of a homopolymer of propylene and an ethylene-propylene copolymer (block copolymer: block PP), and the like. Specific examples of the α-olefin in the copolymer include ethylene and α-olefins having 4 to 20 carbon atoms, such as ethylene, 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene, 1-eicosene, 2-methyl-1-butene, 3-methyl-1-butene, 3,3-dimethyl-1-butene, 3-methyl-1-pentene, and 3-methyl-1-hexene. Among these, ethylene and α-olefins having 4 to 10 carbon atoms are preferred, ethylene and α-olefins having 4 to 8 carbon atoms are more preferred, and ethylene, 1-butene, 1-hexene, 4-methyl-1-pentene, and 1-octene are even more preferred. The molar ratio of propylene to α-olefin (propylene / α-olefin) is preferably 99 / 1 to 60 / 40, more preferably 95 / 5 to 70 / 30, and even more preferably 90 / 10 to 60 / 25.

[0044] Specific examples of suitable propylene-α-olefin copolymers (random PP) include propylene-ethylene copolymers, propylene-1-butene copolymers, propylene-1-hexene copolymers, propylene-4-methyl-1-pentene copolymers, propylene-1-octene copolymers, and propylene-ethylene-1-butene copolymers. Among these, propylene-ethylene copolymers are particularly preferred.

[0045] When the propylene-based polymer is a propylene-ethylene block copolymer (block PP), the propylene-ethylene block copolymer preferably has a room temperature (23°C) decane soluble content of 8 to 35% by mass, more preferably 8 to 28% by mass. The room temperature (23°C) decane soluble content has an intrinsic viscosity [η] measured in decalin at 135°C of 1.0 to 10.0 dL / g. The room temperature (23°C) decane soluble content (the content of structural units derived from ethylene) is preferably 33 to 48 mol%, more preferably 37 to 43 mol%.

[0046] When the propylene polymer is a propylene homopolymer, the melting point is preferably 155 to 170°C, more preferably 158 to 165°C. When the propylene polymer is a propylene-ethylene random copolymer, the ethylene content of the propylene-ethylene random copolymer is preferably 1.9 to 5.4 mass%, more preferably 2.0 to 4.8 mass%. The crystalline melting point of the propylene-ethylene random copolymer measured by differential scanning calorimetry (DSC) according to JIS K7121 is preferably 130 to 150°C, more preferably 130 to 145°C, and particularly preferably 135 to 145°C.

[0047] The propylene-ethylene block copolymer and the propylene-ethylene random copolymer may be used alone or in combination of two or more copolymers, for example, to adjust the MFR.

[0048] <1-butene polymer> The 1-butene polymer is a polymer mainly composed of structural units derived from 1-butene (typically containing more than 50 mol% of structural units derived from 1-butene), such as a homopolymer of 1-butene (polybutene) or a copolymer of 1-butene with ethylene, propylene, and an α-olefin having 5 to 20 carbon atoms (1-butene-α-olefin copolymer).

[0049] Among these polyolefins (b1), propylene polymers are preferred, and propylene homopolymers are more preferred, from the viewpoint of providing a polypropylene resin composition having a better balance between rigidity and impact resistance. The polyolefin (b1) may be used alone or in the form of a mixture of two or more copolymers.

[0050] The MFR (ASTM D1238, 230° C., 2.16 kg load) of the polyolefin (b1) is preferably 1 to 200 g / 10 min, more preferably 5 to 100 g / 10 min, and even more preferably 10 to 70 g / 10 min. When the polyolefin (b1) having an MFR within the above range is used, the phase structure of the polyolefin composition (b) described below is easily formed, and the resulting polypropylene resin composition can have a better balance between rigidity and impact resistance. The monomers used as raw materials for the polyolefin (b1) may be, for example, monomers derived from fossil fuels, monomers derived from biomass, or a combination of monomers derived from fossil fuels and monomers derived from biomass. These monomers may be used alone or in combination of two or more.

[0051] [Aliphatic polyamide resin (b2)] The aliphatic polyamide resin (b2) is not particularly limited, and various known aliphatic polyamide resins can be used without limitation as long as the effects of the present invention are not impaired. For example, a melt-moldable aliphatic polyamide resin obtained by polycondensation reaction of amino acid lactam or diamine and dicarboxylic acid can be used. Specific examples of the aliphatic polyamide resin (b2) include the following resins:

[0052] (1) Polycondensates of organic dicarboxylic acids having 4 to 12 carbon atoms and organic diamines having 2 to 13 carbon atoms, such as polyhexamethylene adipamide [polyamide 66], which is a polycondensate of hexamethylene diamine and adipic acid; polyhexamethylene azelamide [polyamide 69], which is a polycondensate of hexamethylene diamine and azelaic acid; polyhexamethylene sebacamide [polyamide 610], which is a polycondensate of hexamethylene diamine and sebacic acid; polyhexamethylene dodecanoamide [polyamide 612], which is a polycondensate of hexamethylene diamine and dodecanedioic acid; and polyamide 1010, which is a polycondensate of a diamine having 10 carbon atoms (1,10-decanediamine (decamethylenediamine) derived from castor oil) and a dicarboxylic acid having 10 carbon atoms (sebacic acid). Examples of the organic dicarboxylic acid include adipic acid, pimelic acid, suberic acid, sebacic acid, dodecanedioic acid, etc. Examples of the organic diamine include hexamethylenediamine, octamethylenediamine, nonanediamine, octanediamine, decanediamine, undecanediamine, dodecanediamine, etc. (2) Polycondensation products of ω-amino acids, such as polyundecaneamide [polyamide 11], which is a polycondensation product of ω-aminoundecanoic acid. (3) Ring-opening polymers of lactams, such as polycapramide [polyamide 6], which is a ring-opening polymer of ε-aminocaprolactam, and polylauric lactam [polyamide 12], which is a ring-opening polymer of ε-aminolaurolactam.

[0053] Among the aliphatic polyamide resins (b2), polyamide 6, polyamide 11, polyamide 12, polyamide 612, polyamide 610 and polyamide 1010 are preferred, from the viewpoint of providing a polypropylene resin composition having a better balance between rigidity and impact resistance.

[0054] The aliphatic polyamide resin (b2) may be used alone or in combination of two or more. The raw material for the aliphatic polyamide resin (b2) may be either a fossil fuel-derived raw material or a biomass-derived raw material. Alternatively, a fossil fuel-derived raw material and a biomass-derived raw material may be used in combination.

[0055] The melt volume rate (MVR) of the aliphatic polyamide resin (b2) measured at 275°C under a load of 2.16 kg is preferably 50 to 300 cm 3 / 10 min, preferably 100-250 cm 3 / 10 min, and particularly preferably 125 to 200 cm 3 By using such an aliphatic polyamide resin, the impact resistance inherent to the polyamide resin tends to be fully exhibited, and even when the resin is used in combination with the modified elastomer (b3), the impact resistance is not significantly impaired.

[0056] [Modified elastomer (b3)] The modified elastomer (b3) is an elastomer in which a moiety containing a group reactive with the aliphatic polyamide resin (b2) is added to the unmodified elastomer (b3').

[0057] The unmodified elastomer (b3') used as the raw material for the modified elastomer (b3) is an olefin-based thermoplastic elastomer (b3'-1) containing structural units derived from ethylene and structural units derived from an α-olefin having 3 to 8 carbon atoms, or a styrene-based thermoplastic elastomer (b3'-2) containing structural units derived from a styrene-based compound.

[0058] The olefin-based thermoplastic elastomer (b3'-1) is an elastomer containing structural units derived from ethylene and structural units derived from an α-olefin having 3 to 8 carbon atoms, and preferably contains 75 to 95 mol %, more preferably 75 to 90 mol %, of structural units derived from ethylene, and preferably contains 5 to 25 mol %, more preferably 10 to 25 mol %, of structural units derived from an α-olefin having 3 to 8 carbon atoms. Examples of the α-olefins having 3 to 8 carbon atoms include propylene, 1-butene, 1-pentene, 1-hexene, 1-heptene, and 1-octene. Among these α-olefins having 3 to 8 carbon atoms, 1-butene, 1-hexene, and 1-octene are preferred. The α-olefins having 3 to 8 carbon atoms may be used alone or in combination of two or more kinds. The ethylene and α-olefins having 3 to 8 carbon atoms, which are monomers constituting the olefin-based thermoplastic elastomer (b3'-1), may be, for example, monomers derived from fossil fuels and / or monomers derived from biomass, and these monomers may be used alone or in combination of two or more.

[0059] The content of structural units derived from an α-olefin having 3 to 8 carbon atoms in the olefin-based thermoplastic elastomer (b3'-1) is preferably 5 to 25 mol%, more preferably 10 to 25 mol%, even more preferably 11 to 22 mol%, and particularly preferably 12 to 20 mol%. When the content of structural units derived from an α-olefin having 3 to 8 carbon atoms is within the above range, a modified elastomer having good flexibility and easy handling can be obtained. In addition, a polypropylene resin composition having excellent impact resistance can be obtained.

[0060] The melt flow rate (MFR) of the olefinic thermoplastic elastomer (b3'-1), measured at 230°C under a load of 2.16 kg, is preferably 0.1 to 30 g / 10 min, more preferably 0.3 to 20 g / 10 min, and even more preferably 0.5 to 10 (g / 10 min). When the melt flow rate is within the above range, the miscibility of the modified elastomer (b3) in which a reactive group is added to the olefinic thermoplastic elastomer (b3'-1) with the aliphatic polyamide resin (b2) is improved, and a polypropylene resin composition with excellent impact resistance can be obtained.

[0061] The olefin-based thermoplastic elastomer (b3'-1) can be prepared, for example, by randomly copolymerizing ethylene and an α-olefin having 3 to 8 carbon atoms in the presence of a vanadium-based catalyst consisting of a soluble vanadium compound and an alkylaluminum halide compound, or a zirconium-based catalyst consisting of a zirconium metallocene compound and an organoaluminum oxy compound.

[0062] Examples of the styrene-based thermoplastic elastomer (b3'-2) include block copolymers of styrene-based compounds and conjugated diene compounds, and hydrogenated products thereof.

[0063] Examples of the styrene-based compound include styrene, alkylstyrenes such as α-methylstyrene, p-methylstyrene, and pt-butylstyrene, p-methoxystyrene, and vinylnaphthalene. These styrene compounds may be used alone or in combination of two or more. Examples of the conjugated diene compound include butadiene, isoprene, piperylene, methylpentadiene, phenylbutadiene, 3,4-dimethyl-1,3-hexadiene, and 4,5-diethyl-1,3-octadiene. These conjugated diene compounds may be used alone or in combination of two or more.

[0064] Specific examples of the styrene-based thermoplastic elastomer (b3'-2) include styrene-butadiene-styrene copolymer (SBS), styrene-isoprene-styrene copolymer (SIS), styrene-ethylene / butylene-styrene copolymer (SEBS), styrene-ethylene / propylene-styrene copolymer (SEPS), etc. Among these styrene-based thermoplastic elastomers (b3'-2), SEBS is preferred. These styrene-based thermoplastic elastomers (b3'-2) may be used alone or in combination of two or more.

[0065] Examples of the group reactive with the aliphatic polyamide resin (b2) (the group reactive with the aliphatic polyamide resin (b2) that will be contained in the modified elastomer (b3), hereinafter simply referred to as the "reactive group") include an acid anhydride group (-CO-O-OC-), a carboxyl group (-COOH), an epoxy group {-COC- (a three-membered ring structure consisting of two carbon atoms and one oxygen atom)}, an oxazoline group (-C3H4NO), and an isocyanate group (-NCO). The modified elastomer (b3) may contain only one type of these reactive groups, or may contain two or more types.

[0066] The amount of graft modification in the modified elastomer (b3) (the content of the portion derived from the monomer containing a reactive group) is not particularly limited as long as the effects of the present invention are exhibited, but is preferably 0.1 to 5 mass%, more preferably 0.5 to 2 mass%, and even more preferably 0.8 to 1.4 mass%, based on the mass of the modified elastomer (b3).

[0067] There are no particular limitations on the method for adding a moiety containing a reactive group to the unmodified elastomer (b3'), and examples include a method of adding a reactive group by chemically reacting a specific group contained in the unmodified elastomer (b3') (for example, if a carbon-carbon double bond is present in the unmodified elastomer (b3'), an epoxy group is introduced by oxidizing this carbon-carbon double bond), and a method of graft-modifying the unmodified elastomer (b3') with a monomer containing a reactive group and adding it.

[0068] Examples of the monomer having a reactive group used for graft modification include a monomer having a polymerizable unsaturated bond and an acid anhydride group, a monomer having a polymerizable unsaturated bond and a carboxyl group, and a monomer having a polymerizable unsaturated bond and an epoxy group. Specific examples include acid anhydrides such as maleic anhydride, itaconic anhydride, succinic anhydride, glutaric anhydride, adipic anhydride, citraconic anhydride, tetrahydrophthalic anhydride, and butenylsuccinic anhydride; and carboxylic acids such as maleic acid, itaconic acid, fumaric acid, acrylic acid, and methacrylic acid. Among these reactive group-containing monomers, acid anhydrides are preferred, maleic anhydride and itaconic anhydride are more preferred, and maleic anhydride is even more preferred. These reactive group-containing monomers may be used alone or in combination of two or more. The monomer containing a reactive group (e.g., maleic acid or its anhydride) used for graft modification may be a fossil fuel-derived monomer, a biomass-derived monomer, or a combination of a fossil fuel-derived monomer and a biomass-derived monomer.

[0069] When the modified elastomer (b3) is prepared by graft-modifying an unmodified elastomer (b3') with a monomer containing a reactive group, the graft-modification amount of the modified elastomer (b3) is preferably 0.1 to 5 mass%, more preferably 0.5 to 2 mass%, and even more preferably 0.8 to 1.4 mass%. If the modification amount is too small, the impact resistance of the resulting polypropylene resin composition may decrease. If the modification amount is too large, foreign matter such as gel may be mixed into the modified elastomer (b3).

[0070] When the modified elastomer (b3) is produced by graft modification, it can be produced, for example, by graft-modifying the unmodified elastomer (b3') with the above-mentioned carboxylic acid (e.g., maleic acid) or acid anhydride (e.g., maleic anhydride) in the presence of a radical initiator.

[0071] The amount of the carboxylic acid or acid anhydride charged is usually 0.010 to 15 parts by mass, and preferably 0.010 to 5.0 parts by mass, based on 100 parts by mass of the unmodified elastomer (b3'). The amount of the radical initiator used is usually 0.0010 to 1.0 part by mass, and preferably 0.0010 to 0.30 part by mass, based on 100 parts by mass of the unmodified elastomer (b3').

[0072] Examples of the radical initiator include organic peroxides, azo compounds, and metal hydrides. The radical initiator can be used by directly mixing it with the carboxylic acid or acid anhydride and the unmodified elastomer (b3'), or it can be used after dissolving it in a small amount of organic solvent. The organic solvent can be any organic solvent capable of dissolving the radical initiator.

[0073] Graft modification with a carboxylic acid or an acid anhydride can be carried out by a conventionally known method. For example, unmodified elastomer (b3') is dissolved in an organic solvent, and then a carboxylic acid or an acid anhydride and a radical initiator are added to the solution, followed by reaction at a temperature of 70 to 200°C, preferably 80 to 190°C, for 0.5 to 15 hours, preferably 1 to 10 hours, to produce modified elastomer (b3).

[0074] Alternatively, the modified elastomer (b3) can be produced by reacting the unmodified elastomer (b3') with a carboxylic acid or an acid anhydride in the presence of a radical initiator without using a solvent, using an extruder, etc. This reaction is preferably carried out for 0.5 to 10 minutes at a temperature at which the unmodified elastomer (b3') is in a molten state or higher.

[0075] The modified elastomer (b3) has a melt flow rate (MFR) measured at 230°C under a load of 2.16 kg of 0.1 to 50 g / 10 min, preferably 0.5 to 10 g / 10 min. By controlling the MFR within this range, the resulting polypropylene resin composition has excellent impact resistance.

[0076] [Phase structure of polyolefin composition (b)] The polyolefin composition (b) has a continuous phase (α) containing a polyolefin (b1) and a dispersed phase (β) containing an aliphatic polyamide resin (b2) and a modified elastomer (b3) dispersed in the continuous phase (α), and the dispersed phase (β) is made of a melt-kneaded mixture of the aliphatic polyamide resin (b2) and the modified elastomer (b3). When the polyolefin composition (b) having such a phase structure is contained in the polypropylene resin composition, a polypropylene resin composition having an excellent balance between rigidity and impact resistance can be obtained.

[0077] The dispersed phase (β) preferably has a continuous phase (β1) containing the aliphatic polyamide resin (b2) and a finely dispersed phase (β2) containing the modified elastomer (b3) dispersed in the continuous phase (β1). When the dispersed phase (β) has such a phase structure, a polypropylene resin composition having excellent impact resistance can be obtained.

[0078] In the polyolefin composition (b), when a propylene-ethylene block copolymer having a dispersed phase of ethylene blocks is used as the propylene polymer (a1) contained in the propylene polymer composition (a), at least a portion of the ethylene blocks can be aggregated at the interface between the continuous phase (α) and the dispersed phase (β). By having such a phase structure, the impact resistance of the resulting polypropylene resin composition tends to be superior.

[0079] The size of the dispersed phase (β) in the continuous phase (α) of the polyolefin composition (b) is not particularly limited as long as the effects of the present invention are achieved, but its average diameter (average particle diameter) is preferably 10,000 nm or less, more preferably 50 nm or more and 8,000 nm or less, and even more preferably 100 nm or more and 4,000 nm or less. The average diameter of the dispersed phase (β) is the average value (nm) of the maximum lengths of 50 dispersed phases (β) randomly selected in an image obtained during electron microscope observation.

[0080] When the dispersed phase (β) of the polyolefin composition (b) has the continuous phase (β1) and the finely dispersed phase (β2) dispersed in the continuous phase (β1), the size of the finely dispersed phase (β2) is not particularly limited as long as the effects of the present invention are exhibited, but its average diameter (average particle diameter) is preferably 5 nm or more and 1000 nm or less, more preferably 5 nm or more and 600 nm or less, even more preferably 10 nm or more and 400 nm or less, and particularly preferably 15 nm or more and 350 nm or less. The average diameter of the finely dispersed phase (β2) is the average value (nm) of the maximum length of 100 randomly selected finely dispersed phases (β2) in an image obtained using an electron microscope.

[0081] In the polyolefin composition (b), when the total of the continuous phase (α) and the dispersed phase (β) is 100 mass %, the dispersed phase (β) is preferably 80 mass % or less. b1 The total amount of the aliphatic polyamide resin (b2) and the modified elastomer (b3) is W b2+b3 In this case, W b1 and W b2+b3 If the total of these is 100 mass%, then W b2+b3 The proportion is preferably 80% by mass or less (usually 0.5% by mass or more). By setting the amount ratio within the above range, the obtained polypropylene resin composition can be made superior in all of impact resistance, rigidity, and moldability. From this viewpoint, the proportion is preferably 5% by mass or more and 78% by mass or less, more preferably 10% by mass or more and 77% by mass or less, even more preferably 23% by mass or more and 76% by mass or less, even more preferably 30% by mass or more and 75% by mass or less, particularly preferably 33% by mass or more and 72% by mass or less, more particularly preferably 35% by mass or more and 67% by mass or less, and especially preferably 37% by mass or more and 63% by mass or less.

[0082] When the total of the aliphatic polyamide resin (b2) and the modified elastomer (b3) is taken as 100% by mass, the content of the aliphatic polyamide resin (b2) is preferably 10% by mass or more and 80% by mass or less. By setting the content of the aliphatic polyamide resin (b2) within this range, it becomes easier to form a phase structure in which the polyolefin (b1) is the continuous phase (α) and the phase containing the aliphatic polyamide resin (b2) is the dispersed phase (β). This makes it easier to obtain a polypropylene resin composition having excellent impact resistance and excellent rigidity. From this viewpoint, the content of the aliphatic polyamide resin (b2) is preferably 12% by mass or more and 78% by mass or less, more preferably 14% by mass or more and 75% by mass or less, even more preferably 25% by mass or more and 73% by mass or less, even more preferably 30% by mass or more and 71% by mass or less, particularly preferably 34% by mass or more and 68% by mass or less, and even more preferably 40% by mass or more and 64% by mass or less. By setting the content of the aliphatic polyamide resin (b2) within the above range, the dispersed phase (β) obtained from the aliphatic polyamide resin (b2) and the modified elastomer (b3) can be dispersed more finely. Furthermore, the amount of the aliphatic polyamide resin (b2) with a high specific gravity used can be reduced, thereby lowering the specific gravity of the polypropylene resin composition. This allows for a lightweight polypropylene resin composition with excellent impact resistance and rigidity.

[0083] The polyolefin composition (b) used in the present invention can be produced, for example, as follows. First, the aliphatic polyamide resin (b2) and the modified elastomer (b3) are melt-kneaded to obtain a melt-kneaded mixture thereof, for example, in the above-mentioned proportions. The resulting melt-kneaded mixture of the aliphatic polyamide resin (b2) and the modified elastomer (b3) is then melt-kneaded with polyolefin (b1), for example, in the above-mentioned proportions, to obtain the polyolefin composition (b). The melt-kneading method is not particularly limited, and examples thereof include a method of melt-kneading each component using a kneading device such as an extruder (single-screw extruder, twin-screw extruder, etc.), a kneader, or a mixer (high-speed fluid mixer, paddle mixer, ribbon mixer, etc.). These devices may be used alone or in combination of two or more. When preparing the polyolefin composition (b) by melt-kneading, the aliphatic polyamide resin (b2) and the modified elastomer (b3) may be melt-kneaded to prepare a melt-kneaded product, and then this melt-kneaded product may be continuously kneaded with the polyolefin (b1) to prepare the polyolefin composition (b). Alternatively, the aliphatic polyamide resin (b2) and the modified elastomer (b3) may be melt-kneaded to prepare a melt-kneaded product, and pellets of this melt-kneaded product may be prepared, and then the pellets of this melt-kneaded product may be melt-kneaded with the polyolefin (b1) to prepare the polyolefin composition (b). In addition, when melt-kneading, the components may be added all at once and melt-kneaded, or the components may be added in several batches and melt-kneaded. The melt-kneading temperature can be set appropriately depending on the type of resin used, but it is desirable to knead each component in a molten state, and the temperature is usually 190 to 350°C, preferably 200 to 330°C, and more preferably 205 to 310°C.

[0084] <Acid-modified polypropylene (c)> The acid-modified polypropylene (c) is an acid-modified product of unmodified polypropylene. The acid-modified polypropylene (c) can be obtained by acid-modifying unmodified polypropylene with a compound selected from unsaturated carboxylic acids and their derivatives, preferably by modifying unmodified polypropylene with maleic acid or its anhydride. The acid-modified polypropylene (c) may be prepared using a single unmodified polypropylene or a combination of two or more unmodified polypropylenes. The monomers used as raw materials for the acid-modified polypropylene (c) may be, for example, fossil fuel-derived monomers, biomass-derived monomers, or a combination of fossil fuel-derived monomers and biomass-derived monomers. These monomers may be used alone or in combination of two or more.

[0085] The acid-modified polypropylene (c) can be produced, for example, by graft-modifying unmodified polypropylene with a compound selected from unsaturated carboxylic acids and their derivatives. When producing the acid-modified polypropylene (c) by graft-modification, for example, the unmodified polypropylene can be graft-modified with an unsaturated carboxylic acid (e.g., maleic acid) or an unsaturated carboxylic acid derivative (e.g., an acid anhydride such as maleic anhydride) in the presence of a radical initiator. The conditions for graft-modification are the same as those for producing the modified elastomer (b3) by graft-modification. Examples of radical initiators that can be used in producing the acid-modified polypropylene (c) by graft modification include 1,1-di(t-butylperoxy)cyclohexane, 2,2-di(4,4-di-(t-butylperoxy)cyclohexyl)propane, t-hexylperoxyisopropyl monocarbonate, t-butylperoxymaleic acid, t-butylperoxy-3,5,5-trimethylhexanoate, t-butylperoxylaurate, t-butylperoxyisopropyl monocarbonate, t-butylperoxy-2-ethylhexyl monocarbonate, t-hexylperoxybenzoate, 2,5-dimethyl-2,5-di(benzoylperoxy)hexane, t-butylperoxyacetate, 2,2-di(t-butylperoxy)butane, t-butylperoxybenzoate, n-butyl-4,4- Examples of suitable peroxides include di(t-butylperoxy)valerate, di(2-t-butylperoxyisopropyl)benzene, dicumyl peroxide, di-t-hexyl peroxide, 2,5-dimethyl-2,5-di(t-butylperoxy)hexane, t-butylcumyl peroxide, di-t-butyl peroxide, and 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane. Among these, 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane is preferred.

[0086] The acid-modified polypropylene (c) preferably satisfies at least one of the following requirements (ci) and (c-ii), and more preferably satisfies both of the following requirements (ci) and (c-ii).

[0087] Requirements (CI) The acid-modified polypropylene (c) has a melt flow rate (MFR) of 100 to 300 g / 10 min at 230°C under a load of 2.16 kg. The melt flow rate of the acid-modified polypropylene (c) can be measured in accordance with ASTM D1238 under conditions of 230°C under a load of 2.16 kg. The melt flow rate of the acid-modified polypropylene (c) is preferably 120 to 280 g / 10 min, more preferably 140 to 260 g / 10 min, and even more preferably 160 to 240 g / 10 min. When the acid-modified polypropylene (c) has a melt flow rate within the above range, the strength of the resulting polypropylene resin composition tends to be superior.

[0088] Requirement (c-ii) Density: 895-920 kg / m 3 The density of the acid-modified polypropylene (c) can be measured in accordance with ASTM D1505. The density of the acid-modified polyolefin (c) is preferably 896 to 915 kg / m 3 , more preferably 897 to 910 kg / m 3 The range is. When the density of the acid-modified polyolefin (c) is within the above range, the handleability of the pellets of the acid-modified polyolefin (c) is excellent, and the decrease in rigidity of the resulting polypropylene resin composition tends to be further suppressed.

[0089] The polypropylene resin composition of the present invention may further contain the following ethylene copolymer (d).

[0090] <Ethylene copolymer (d)> The ethylene copolymer (d) is a copolymer consisting of only ethylene and an α-olefin having 3 to 20 carbon atoms, and is preferably a copolymer of ethylene and an α-olefin having 3 to 10 carbon atoms. That is, the ethylene copolymer (d) according to the present invention is a copolymer consisting of structural units derived from ethylene and structural units derived from an α-olefin having 3 to 20 carbon atoms.

[0091] Examples of the α-olefin having 3 to 20 carbon atoms as a copolymerization component include propylene, 1-butene, 1-pentene, 3-methyl-1-butene, 4-methyl-1-pentene, 1-hexene, 1-octene, 1-decene, 1-dodecene, and 1-tetradecene. The α-olefin having 3 to 20 carbon atoms is preferably an α-olefin having 3 to 10 carbon atoms. The α-olefin having 3 to 20 carbon atoms as a copolymerization component may be used alone or in combination of two or more. The ethylene and α-olefins having 3 to 20 carbon atoms, which are monomers constituting the ethylene copolymer (d), may be, for example, monomers derived from fossil fuels and / or monomers derived from biomass, and these monomers may be used alone or in combination of two or more.

[0092] Of these, the ethylene copolymer (d) is particularly preferably an ethylene-1-butene copolymer. The type of α-olefin constituting the ethylene copolymer (d) is clear depending on the type of copolymerization monomer used in producing the ethylene copolymer (d). However, the type of α-olefin in the ethylene copolymer can be determined by, for example, dissolving approximately 200 mg of the ethylene copolymer uniformly in 1 ml of hexachlorobutadiene in a 10 mm diameter sample tube. 13 The C-NMR spectrum can be measured and identified under the following measurement conditions: temperature 120°C, frequency 25.05 MHz, spectrum width 1500 Hz, pulse repetition time 4.2 seconds, 45° pulse width 6 μsec.

[0093] The content of structural units derived from ethylene in the ethylene copolymer (d) (ethylene content) is not particularly limited, but is usually 50 to 99 mol%, preferably 60 to 98 mol%, more preferably 75 to 97 mol% of the total structural units in the ethylene copolymer (d). The content of structural units derived from an α-olefin having 3 to 20 carbon atoms in the ethylene copolymer (d) (α-olefin content) is usually 1 to 50 mol%, preferably 2 to 40 mol%, more preferably 3 to 25 mol% of the total structural units in the ethylene copolymer (d).

[0094] The ethylene copolymer (d) preferably satisfies at least one of the following requirements (di) and (d-ii), and more preferably satisfies both of the following requirements (di) and (d-ii).

[0095] (di) Melt flow rate The ethylene copolymer (d) has a melt flow rate (MFR) of 0.1 to 50 g / 10 min, measured at 190°C under a load of 2.16 kg. The melt flow rate (MFR) of the ethylene copolymer (d) can be measured in accordance with ASTM D1238 under conditions of 190°C under a load of 2.16 kg. The melt flow rate of the ethylene copolymer (d) is preferably in the range of 0.2 to 25 g / 10 min, more preferably 0.3 to 10 g / 10 min. When the ethylene copolymer (d) has a melt flow rate within the above range, the strength of the resulting polypropylene resin composition tends to be high, dispersibility in the polypropylene resin composition tends to be good, and the impact resistance of the resulting polypropylene resin composition is superior.

[0096] (d-ii) Density The density of the ethylene copolymer (d) is 850 to 890 kg / m 3 The density of the ethylene copolymer (d) can be measured in accordance with ASTM D1505. The density of the ethylene copolymer (d) is preferably 853 to 880 kg / m 3 and more preferably 855 to 870 kg / m 3When the density of the ethylene copolymer (d) is within the above range, the pellets of the ethylene copolymer (d) are easy to handle, and the polypropylene resin composition has excellent impact resistance at room temperature and low temperature.

[0097] In the polypropylene resin composition of the present invention, when the ethylene copolymer (d) is contained, it is preferable that the content of the propylene polymer composition (a) is 50 to 89.9 parts by mass, the content of the polyolefin composition (b) is 5 to 44.9 parts by mass, the content of the modified polypropylene (c) is 0.1 to 15 parts by mass, and the content of the ethylene copolymer (d) is 5 to 30 parts by mass, where the total content of the propylene polymer composition (a), the polyolefin composition (b), the modified polypropylene (c), and the ethylene copolymer (d) is 100 parts by mass. More preferably, the content of the propylene polymer composition (a) is 55 to 85.5 parts by mass, the content of the polyolefin composition (b) is 8 to 30 parts by mass, the content of the modified polypropylene (c) is 1 to 12 parts by mass, and the content of the ethylene copolymer (d) is 5 to 25 parts by mass, and even more preferably, the content of the propylene polymer composition (a) is 60 to 80 parts by mass, the content of the polyolefin composition (b) is 10 to 25 parts by mass, the content of the modified polypropylene (c) is 2.5 to 11 parts by mass, and the content of the ethylene copolymer (d) is 8 to 20 parts by mass. By including each component in such a blending ratio, the resulting polypropylene resin composition tends to have a better balance between rigidity and heat resistance. Furthermore, in the polypropylene resin composition of the present invention, when the ethylene copolymer (d) is contained, it is preferable that, when the total content of the propylene polymer composition (a), the polyolefin composition (b), the modified polypropylene (c), and the ethylene copolymer (d) is taken as 100 parts by mass, the content of the propylene polymer composition (a) is 50 to 89.9 parts by mass, the content of the polyolefin composition (b) is 5 to 44.9 parts by mass, the content of the modified polypropylene (c) is 0.1 to 5 parts by mass, and the content of the ethylene copolymer (d) is 5 to 30 parts by mass. More preferably, the content of the propylene polymer composition (a) is 55 to 85 parts by mass, the content of the polyolefin composition (b) is 8 to 30 parts by mass, the content of the modified polypropylene (c) is 0.5 to 4 parts by mass, and the content of the ethylene copolymer (d) is 5 to 25 parts by mass, and even more preferably, the content of the propylene polymer composition (a) is 60 to 80 parts by mass, the content of the polyolefin composition (b) is 10 to 25 parts by mass, the content of the modified polypropylene (c) is 1 to 3 parts by mass, and the content of the ethylene copolymer (d) is 8 to 20 parts by mass. When the components are contained in such a blending ratio, the resulting polypropylene resin composition tends to have a better balance between rigidity and impact resistance.

[0098] The polypropylene resin composition of the present invention may contain, in addition to the propylene polymer composition (a), the polyolefin composition (b), and the acid-modified polypropylene (c), other polymers such as the above-mentioned ethylene copolymer (d) within the range that does not impair the effects of the present invention. The other polymers may be used alone or in combination of two or more. The polypropylene resin composition of the present invention may contain additives within the range that does not impair the effects of the present invention. Examples of such additives include flame retardants, flame retardant auxiliaries, fillers, colorants, antibacterial agents, antistatic agents, etc. The additives may be used alone or in combination of two or more.

[0099] In the polypropylene resin composition of the present invention, the propylene polymer (a1) contained in the propylene polymer composition (a), the polyolefin (b1) contained in the polyolefin composition (b), and the acid-modified polypropylene (c) are integrated to form a continuous phase (α'). Furthermore, a dispersed phase (β) formed of a filler (a2) and a polyolefin composition (b) is usually dispersed in this continuous phase (α'). Furthermore, in the polyolefin composition (b), when the dispersed phase (β) has a continuous phase (β1) containing an aliphatic polyamide resin (b2) and a finely dispersed phase (β2) containing a modified elastomer (b3) dispersed in the continuous phase (β1), the dispersed phase (β) is usually dispersed in this continuous phase (α') in a state where the continuous phase (β1) and the finely dispersed phase (β2) dispersed in the continuous phase (β1) are formed in the dispersed phase (β). By having such a multiple dispersed phase structure, a polypropylene resin composition having better impact resistance can be obtained.

[0100] When a propylene-ethylene block copolymer having a dispersed phase of ethylene polymer blocks is used as the propylene polymer (a1), at least a portion of the ethylene polymer blocks contained in the block copolymer can be aggregated at the interface between the continuous phase (α') and the dispersed phase (β). Such a phase structure allows the production of a polypropylene resin composition with superior impact resistance.

[0101] The size of the dispersed phase (β) contained in the continuous phase (α') of the polypropylene resin composition is not particularly limited as long as the effects of the present invention are achieved, but is usually the same as the preferred embodiment of the size of the dispersed phase (β) of the above-mentioned polyolefin composition (b). Furthermore, when a finely dispersed phase (β2) is formed within the dispersed phase (β) of the polypropylene resin composition of the present invention, its size is not particularly limited as long as the effects of the present invention are achieved, but it is usually the same as the preferred embodiment of the size of the finely dispersed phase (β2) of the polyolefin composition (b) above. In the polypropylene resin composition of the present invention, the acid-modified polypropylene (c) is thought to be localized around the filler (a2). On the other hand, in a polypropylene resin composition that does not contain the acid-modified polypropylene (c), the dispersed phase (β) in the polyolefin composition (b) tends to be localized around the filler (a2). Due to such differences in phase structure, the polypropylene resin composition of the present invention has a higher rigidity than a polypropylene resin composition that does not contain the acid-modified polypropylene (c).

[0102] When the polypropylene resin composition of the present invention contains an ethylene-based copolymer (d), the ethylene-based copolymer (d) preferably forms a dispersed phase (γ) in the continuous phase (α'). This dispersed phase (γ) is formed. The formation of this phase structure tends to result in a better balance between rigidity and impact resistance of the resulting polypropylene resin composition. When a dispersed phase (γ) of the ethylene-based copolymer (d) is formed in the polypropylene resin composition of the present invention, the size of the dispersed phase (γ) is not particularly limited as long as the effects of the present invention are achieved, but the average diameter (average particle diameter) is preferably 100 nm or more and 1,000 nm or less, more preferably 100 nm or more and 500 nm or less, and even more preferably 100 nm or more and 300 nm or less. The average diameter of the dispersed phase (γ) is the average value (nm) of the maximum lengths of 100 randomly selected fine dispersed phases (γ) in an image obtained using an electron microscope.

[0103] In the polypropylene resin composition of the present invention, when the total of the continuous phase (α') and the dispersed phase (β) is 100 mass%, the dispersed phase (β) is 80 mass% or less. Therefore, the total amount of the propylene polymer (a1) and the polyolefin (b1) is usually set to W a1+b1 The total amount of the aliphatic polyamide resin (b2) and the modified elastomer (b3) is W b2+b3 In this case, W a1+b1 and W b2+b3 and 100% by mass of the total, W b2+b3The proportion is 80% by mass or less (usually 0.5% by mass or more). By setting the amount ratio within the above range, the obtained polypropylene resin composition can be made superior in all of impact resistance, rigidity, and moldability. From this viewpoint, the proportion is preferably 1% by mass or more and 78% by mass or less, more preferably 3% by mass or more and 77% by mass or less, even more preferably 5% by mass or more and 76% by mass or less, even more preferably 8% by mass or more and 75% by mass or less, particularly preferably 10% by mass or more and 72% by mass or less, more particularly preferably 15% by mass or more and 67% by mass or less, and especially preferably 25% by mass or more and 63% by mass or less.

[0104] In the polypropylene resin composition of the present invention, the respective contents of the propylene polymer (a1) and the polyolefin (b1) are not particularly limited as long as the effects of the present invention are achieved. However, the content of the polyolefin (b1) relative to the total of the propylene polymer (a1) and the polyolefin (b1) (100% by mass) is usually 80% by mass or less, preferably 1% by mass or more and 60% by mass or less, more preferably 3% by mass or more and 40% by mass or less, even more preferably 5% by mass or more and 30% by mass or less, and still more preferably 10% by mass or more and 25% by mass or less.

[0105] The specific gravity of the polypropylene resin composition of the present invention is not particularly limited, but is usually 1.05 or less, preferably 0.89 or more and 1.05 or less, more preferably 0.92 or more and 0.98 or less. Although the polypropylene resin composition of the present invention has such a specific gravity, it has better impact resistance and rigidity than polyethylene resin alone or polypropylene resin alone.

[0106] In the polypropylene resin composition of the present invention, when the total content of the propylene polymer composition (a), the polyolefin composition (b), and the modified polypropylene (c) is taken as 100 parts by mass, the content of the propylene polymer composition (a) is preferably 50 to 94.9 parts by mass, the content of the polyolefin composition (b) is 5 to 49.9 parts by mass, and the content of the modified polypropylene (c) is 0.1 to 15 parts by mass, more preferably the content of the propylene polymer composition (a) is 55 to 90.5 parts by mass, the content of the polyolefin composition (b) is 8 to 40 parts by mass, and the content of the modified polypropylene (c) is 1 to 12 parts by mass, and even more preferably the content of the propylene polymer composition (a) is 60 to 80 parts by mass, the content of the polyolefin composition (b) is 10 to 29 parts by mass, and the content of the modified polypropylene (c) is 2.5 to 11 parts by mass. By including each component in such a blending ratio, the resulting polypropylene resin composition tends to have a better balance between rigidity and impact resistance. In the polypropylene resin composition of the present invention, when the total content of the propylene polymer composition (a), the polyolefin composition (b), and the modified polypropylene (c) is taken as 100 parts by mass, it is preferred that the content of the propylene polymer composition (a) is 50 to 94.9 parts by mass, the content of the polyolefin composition (b) is 4 to 49.9 parts by mass, and the content of the modified polypropylene (c) is 0.1 to 5 parts by mass. It is more preferable that the content of the propylene polymer composition (a) is 60 to 90 parts by mass, the content of the polyolefin composition (b) is 6 to 35 parts by mass, and the content of the modified polypropylene (c) is 0.5 to 4 parts by mass, and it is even more preferable that the content of the propylene polymer composition (a) is 65 to 88 parts by mass, the content of the polyolefin composition (b) is 8 to 30 parts by mass, and the content of the modified polypropylene (c) is 1 to 3.5 parts by mass. When the components are contained in such a blending ratio, the resulting polypropylene resin composition tends to have a better balance between rigidity and impact resistance.

[0107] The polypropylene resin composition of the present invention can be produced, for example, as follows. For example, the propylene polymer composition (a) and the polyolefin composition (b) are prepared by the method described above. The propylene polymer composition (a), the polyolefin composition (b), and the acid-modified polypropylene (c) are then melt-kneaded with other polymers, such as an ethylene copolymer (d), and additives, if necessary. Alternatively, the propylene polymer composition (a1) and the filler (a2) may be added instead of the propylene polymer composition (a), i.e., the propylene polymer (a1), the filler (a2), the polyolefin composition (b), and the acid-modified polypropylene (c) may be melt-kneaded with other polymers, such as an ethylene copolymer (d), and additives, if necessary. The melt-kneading method is not particularly limited, and examples thereof include a method of melt-kneading each component using a kneading device such as an extruder (single-screw extruder, twin-screw extruder, etc.), a kneader, or a mixer (high-speed fluid mixer, paddle mixer, ribbon mixer, etc.). These devices may be used alone or in combination of two or more. In addition, when melt-kneading, the components may be added all at once and melt-kneaded, or the components may be added in several batches and melt-kneaded. The melt-kneading temperature can be set appropriately depending on the type of resin used, but it is desirable to knead each component in a molten state, and the temperature is usually 190 to 350°C, preferably 200 to 330°C, and more preferably 205 to 310°C.

[0108] The polypropylene resin composition of the present invention can be molded into a molded article by various thermoforming processes. The molded article thus obtained usually has a phase structure formed by the above-mentioned polypropylene resin composition. Therefore, the molded article obtained has an excellent balance between rigidity and impact resistance. Examples of the above-mentioned thermoforming methods include injection molding, extrusion molding, blow molding, injection blow molding, inflation molding, hollow molding, vacuum molding, compression molding, press molding, stamping molding, and transfer molding. The molded article may be produced by only one molding method, or may be produced by a combination of two or more molding methods.

[0109] The polypropylene resin composition of the present invention can be used for various purposes. For example, the polypropylene resin composition of the present invention is used as various parts for vehicles such as automobiles, railway vehicles (vehicles in general), aircraft bodies (aircraft bodies in general), ships and hulls (hulls in general), and bicycles (car bodies in general). Examples of automotive parts include exterior parts, interior parts, engine parts, and electrical parts. [Example]

[0110] The present invention will be explained in more detail below based on examples, but the present invention is not limited to these examples.

[0111] [Manufacturing example] <Production Example 1> Preparation of maleic anhydride grafted ethylene-1-butene copolymer (modified elastomer (b3-1)) The ethylene-1-butene copolymers shown in Table 1 below were used to produce maleic anhydride-grafted modified ethylene-1-butene copolymers (modified elastomers (b3-1)).

[0112] [Table 1]

[0113] 10 kg of the ethylene-1-butene copolymer was blended in a Henschel mixer with a solution of 110 g of maleic anhydride and 6 g of 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexene-3 in 80 g of acetone. The resulting blend was fed into a twin-screw melt-kneading extruder (Nippon Steel Works, Ltd., screw diameter 30 mm, L / D = 42) and extruded into strands at a resin temperature of 260°C and an extrusion rate of 7 kg / h. The resulting mixture was then water-cooled and pelletized to obtain a maleic anhydride-grafted ethylene-1-butene copolymer (hereinafter also referred to as the "modified elastomer"). The resulting modified elastomer had an MFR (190°C, 2.16 kg load) of 0.6 g / 10 min, an MFR (230°C, 2.16 kg load) of 1.2 g / 10 min, and a density of 866 kg / m 3 The amount of grafted maleic anhydride was measured after extracting unreacted maleic anhydride with acetone, and was found to be 0.99% by mass.

[0114] <Production Example 2> Preparation of polyolefin composition (b-1) PA6 (nylon 6 resin, manufactured by Toray Industries, Inc., product name "Amilan CM1007", melting point 225°C) was used as the aliphatic polyamide resin (b2), and the modified elastomer (b3-1) obtained in Production Example 1 was used as the modified elastomer (b3). These pellets were dry-blended so that the PA6 / modified elastomer (b3-1) ratio was 44.4 / 55.6% by mass, and then charged into a twin-screw melt-kneading extruder (manufactured by Nippon Steel Works, Ltd., screw diameter 30 mm, L / D = 42). Next, mixing was carried out under conditions of a kneading temperature of 245°C, an extrusion rate of 15 kg / hour, and a screw rotation speed of 200 rpm. The extruded mixed resin was further cut using a pelletizer to produce mixed resin pellets. Next, polypropylene resin (homopolypropylene, manufactured by Prime Polymer Co., Ltd., product name "Prime Polypro J106G", melting point 163 ° C.) (hereinafter also referred to as "hPP") was used as polyolefin (b1), and the mixed resin pellets obtained earlier were dry-blended to a ratio of hPP / mixed resin pellets = 55 / 45% by mass, and then charged into a twin-screw melt kneading extruder (manufactured by Nippon Steel Works, Ltd., screw diameter 30 mm, L / D = 42). Next, mixing was carried out under conditions of a kneading temperature of 245 ° C., an extrusion rate of 15 kg / hour, and a screw rotation speed of 200 rpm, and the extruded polyolefin composition was further cut using a pelletizer to produce pellets of polyolefin composition (b-1).

[0115] <Production Example 3> Preparation of propylene polymer composition (a-1) A propylene-ethylene block copolymer (a1) having an ethylene block dispersed phase (Prime Polypro J739E, manufactured by Prime Polymer Co., Ltd.; n-decane-insoluble component at 23°C: 89% by mass, n-decane-soluble component at 23°C: 11% by mass, [η] of n-decane-soluble component at 23°C: 6.2 dl / g, MFR: 54 g / 10 min (230°C, 2.16 kg load)) (hereinafter also referred to as "bPP") and a talc-containing polypropylene resin (HG-170, manufactured by Asada Flour Milling Co., Ltd.; talc content: 70 wt%) (hereinafter also referred to as "Talc MB") (a2-1) were dry-blended to a bPP / Talc MB ratio of 80 / 20 by mass, and then charged into a twin-screw melt-kneading extruder (Japan Steel Works, Ltd.; screw diameter: 30 mm; L / D = 42). Next, mixing was carried out under conditions of a kneading temperature of 200°C, an extrusion rate of 15 kg / hour, and a screw rotation rate of 200 rpm, and the extruded mixed resin was cut using a pelletizer to prepare pellets of a propylene polymer composition (a-1).

[0116] <Production Example 4> Preparation of propylene polymer compositions (a-2-1) and (a-2-2) Pellets of propylene-based polymer compositions (a-2-1) and (a-2-2) were prepared in the same manner as in Production Example 3, except that talc was replaced with cellulose fiber (manufactured by Nippon Paper Industries Co., Ltd., product name "KC Flock W-50GK"), which is a natural fiber (a-2-2), and the cellulose fibers were dry-blended to a bPP / cellulose fiber ratio of 90 / 10% by mass (propylene-based polymer composition (a-2-1)) or 80 / 20% by mass (propylene-based polymer composition (a-2-2)).

[0117] [Examples 1 to 3] (1) Preparation of polypropylene resin composition The propylene polymer composition (a) was the propylene polymer composition (a-1) obtained in Production Example 3, the polyolefin composition (b) was the polyolefin composition (b-1) obtained in Production Example 2, and the acid-modified polypropylene (c) was maleic anhydride-modified polypropylene (c-1) (manufactured by Mitsui Chemicals, Inc., product name "Admer AT2606", MFR: 220 g / 10 min (230°C, 2.16 kg load), density: 900 kg / m 3 ) to obtain the composition shown in Table 2, and then the mixture was charged into a twin-screw melt kneading extruder (manufactured by Nippon Steel Works, Ltd., screw diameter 30 mm, L / D = 42). Next, mixing was carried out under conditions of a kneading temperature of 200°C, an extrusion rate of 15 kg / hour, and a screw rotation speed of 200 rpm, and the extruded polypropylene resin composition was further cut using a pelletizer to prepare pellets of the polypropylene resin composition.

[0118] (2) Preparation of test specimens for measuring physical properties The pellets of the polypropylene resin composition obtained in (1) were placed in the hopper of a 50-ton injection molding machine (manufactured by Meiki Seisakusho Co., Ltd.), and test pieces for bending tests, tensile tests, Charpy impact tests, and load deflection temperature measurements were injection molded under injection conditions of a set temperature of 200°C and a mold temperature of 40°C. Similarly, using a 70-ton injection molding machine (manufactured by Meiki Seisakusho Co., Ltd.), square plates for puncture impact tests and Rockwell hardness measurements were injection molded under injection conditions of a set temperature of 200°C and a mold temperature of 40°C.

[0119] (3) Charpy impact strength Under the following test conditions, a hammer was swung down from the back of the notch of the fixed test piece, and the impact strength was determined from the angle at which the hammer swung up after the test piece broke and the angle at which the hammer was lifted up before the test. (Test conditions) Test temperature: 23℃ / -30℃, hammer capacity: 4J, lifting angle: 149.9, test piece: notched, remaining width 8mm, width 4mm

[0120] (4) Deflection temperature under load Under the following test conditions, a specified test load (0.45 MPa) was applied to the test piece, and the temperature was raised in the heat transfer medium, and the temperature at which the deflection reached 0.34 mm was determined. (Test conditions) Test start temperature: 35.0°C, heating rate: 120°C / h, test piece: length 80mm x width 10mm x thickness 4mm, test piece direction: flatwise, test load: 0.45MPa

[0121] (5) Rockwell hardness The test load was applied to the test piece for 15 seconds under the following test conditions, and then the test load was removed. The hardness was calculated based on the indentation depth 15 seconds after the test load was removed. (Test conditions) Test temperature: 23°C, Test load: 60 kg, Scale: HRR, Test piece: 2 stacked 3 mm thick injection square plates

[0122] (6) Evaluation of rigidity (measurement of bending modulus) The test piece obtained in (2) above was used to measure the flexural modulus in accordance with JIS K7171. The results are shown in Table 2. The flexural modulus was measured by supporting the test piece at two supports (with a radius of curvature of 5 mm) with a distance (L) between the supports of 64 mm, and applying a load at a rate of 2 mm / min from a point of application (with a radius of curvature of 5 mm) located at the center between the supports.

[0123] (7) Tensile test Measurements were carried out under the following test conditions to determine the tensile elongation at break (between chucks) and the tensile modulus of elasticity. (Test conditions) Measurement temperature: 23°C, Test speed: 50mm / min, Test piece: ISO527 1A, Chuck distance: 115mm Tensile modulus calculation formula: Et=(σ2-σ1) / (ε2-ε1) Et: Tensile modulus (MPa) σ1: Stress (MPa) at strain ε1 = 0.0005 (0.05%) σ2: Stress (MPa) at strain ε2 = 0.0025 (0.25%) (The strain used was the strain between the chucks.)

[0124] (8) Puncture impact test Measurements were carried out under the following test conditions to determine the displacement / energy at the maximum impact force point and the displacement / energy at the puncture point. (Test conditions) Test temperature: 23℃ / -30℃, test speed: 5m / sec, striker diameter: 0.5 inches, support diameter: 3 inches, test piece: approximately 1mm thick injection square plate The displacement at the point where the stress was greatest on the stress-displacement curve obtained in the test was defined as the maximum impact point displacement, and the integral value of the curve from the test start point to that point was defined as the maximum impact point energy.The point where the displacement was greater than the maximum impact point and the stress was half that of the maximum impact point was defined as the puncture point, and the displacement at that point was defined as the puncture point displacement, and the integral value of the curve from the test start point to that point was defined as the puncture point energy.

[0125] [Examples 4 to 7] In addition to the propylene-based polymer composition (a-1), polyolefin composition (b-1), and maleic anhydride-modified polypropylene used in Examples 1 to 3, an ethylene-1-butene copolymer (manufactured by Mitsui Chemicals, Inc., product name "Tafmer DF610", density = 862 kg / m) was used as the ethylene-based copolymer (d). 3 ) were dry-blended to obtain the formulation shown in Table 2, and pellets of the polypropylene resin composition were prepared in the same manner as in Examples 1 to 3, and test pieces for measuring physical properties were injection-molded and evaluated. The results are shown in Table 2.

[0126] [Examples 8 to 10] Pellets of the polypropylene resin composition were prepared in the same manner as in Examples 1 to 3, except that the propylene polymer composition (a-1) of the propylene polymer composition (a) was changed to the propylene polymer composition (a-2-1) or (a-2-2) prepared in Production Example 4, and the components were blended in the proportions shown in Table 3. Test pieces for measuring physical properties were injection-molded and evaluated. The results are shown in Table 3.

[0127] [Examples 11 to 12] Pellets of the polypropylene resin composition were prepared in the same manner as in Examples 1 to 3, except that the propylene polymer composition (a-1) of the propylene polymer composition (a) was changed to the propylene polymer composition (a-2-2) prepared in Production Example 4, and the components were blended in the proportions shown in Table 4. Test pieces for measuring physical properties were injection-molded and evaluated. The results are shown in Table 4.

[0128] [Examples 13 to 14] The propylene polymer composition (a-1) as the propylene polymer composition (a) was replaced with the propylene polymer composition (a-2-2) prepared in Production Example 4, and maleic anhydride-modified polypropylene (c-2) (manufactured by Mitsui Chemicals, Inc., product name "Admer AT3190", MFR: 235 g / 10 min (190°C, 2.16 kg load), density: 900 kg / m 3 ) and the blending ratio of each component was changed to Table 4, and pellets of the polypropylene resin composition were prepared in the same manner as in Examples 1 to 3, and test pieces for measuring physical properties were injection molded and evaluated. The results are shown in Table 4.

[0129] [Comparative Example 1] Test pieces for measuring physical properties were injection molded and evaluated in the same manner as in Examples 1 to 3, except that only the propylene polymer composition (a-1) obtained in Production Example 3 was used. The results are shown in Table 2.

[0130] [Comparative Examples 2 to 4] Pellets of the polypropylene resin composition were prepared in the same manner as in Examples 1 to 3, except that the propylene polymer composition (a) was the propylene polymer composition (a-1) obtained in Production Example 3, and the polyolefin composition (b-1) was the polyolefin composition (b) was dry-blended to obtain the formulation shown in Table 2. Test pieces for measuring physical properties were injection-molded and evaluated. The results are shown in Table 2.

[0131] [Comparative Examples 5 to 8] Pellets of the polypropylene resin composition were prepared in the same manner as in Examples 1 to 3, except that the propylene polymer composition (a-1) obtained in Production Example 3 was used as the propylene polymer composition (a), the polyolefin composition (b-1) obtained in Production Example 2 was used as the polyolefin composition (b), and an ethylene-based elastomer were dry-blended to obtain the formulation shown in Table 2. Test pieces for measuring physical properties were injection-molded and evaluated. The results are shown in Table 2.

[0132] [Comparative Examples 9 to 11] Pellets of the polypropylene resin composition were prepared in the same manner as in Comparative Examples 5 to 8, except that the propylene polymer composition (a-1) in the propylene polymer composition (a) was changed to the propylene polymer composition (a-2-1) or (a-2-2) prepared in Production Example 4, and the components were dry-blended to obtain the blending ratios shown in Table 3. Test pieces for measuring physical properties were injection-molded and evaluated. The results are shown in Table 3.

[0133] [Table 2]

[0134] [Table 3]

[0135] [Table 4]

Claims

1. A polypropylene resin composition comprising a propylene polymer composition (a), a polyolefin composition (b), and an acid-modified polypropylene (c), The propylene polymer composition (a) contains a propylene polymer (a1) and a filler (a2), The polyolefin composition (b) comprises a polyolefin (b1), an aliphatic polyamide resin (b2), and a modified elastomer (b3), and A continuous phase (α) containing a polyolefin (b1) and a dispersed phase (β) containing an aliphatic polyamide resin (b2) and a modified elastomer (b3) dispersed in the continuous phase (α), the dispersed phase (β) is composed of a melt-kneaded mixture of the aliphatic polyamide resin (b2) and the modified elastomer (b3), the modified elastomer (b3) is an elastomer in which a moiety containing a group reactive with the aliphatic polyamide resin (b2) is added to an unmodified elastomer (b3'), and the unmodified elastomer (b3') is an olefin-based thermoplastic elastomer containing a structural unit derived from ethylene and a structural unit derived from an α-olefin having 3 to 8 carbon atoms, or a styrene-based thermoplastic elastomer containing a structural unit derived from a styrene-based compound; the reactive group is at least one selected from the group consisting of an acid anhydride group, a carboxyl group, an epoxy group, an oxazoline group, and an isocyanate group; A polypropylene resin composition characterized in that the dispersed phase (β) accounts for 80 mass% or less when the total of the continuous phase (α) and the dispersed phase (β) is 100 mass%.

2. The polypropylene resin composition according to claim 1, wherein the filler (a2) is an inorganic filler (a2-1).

3. The polypropylene resin composition according to claim 1, wherein the filler (a2) is a natural fiber (a2-2).

4. 2. The polypropylene resin composition according to claim 1, wherein the propylene polymer (a1) is a propylene-ethylene block copolymer having a dispersed phase of an ethylene polymer block.

5. 3. The polypropylene resin composition according to claim 2, wherein the inorganic filler (a2-1) is one or more inorganic fillers selected from the group consisting of talc, mica, glass fiber, and calcium carbonate.

6. The polypropylene resin composition according to claim 3, wherein the natural fibers (a2-2) are one or more natural fibers selected from the group consisting of wood fibers, bamboo fibers, cotton, and cellulose fibers.

7. The polypropylene resin composition according to claim 1, wherein the polyolefin (b1) is a propylene homopolymer.

8. 2. The polypropylene resin composition according to claim 1, wherein the aliphatic polyamide resin (b2) is one or more aliphatic polyamide resins selected from the group consisting of polyamide 6, polyamide 11, polyamide 12, polyamide 612, polyamide 610, and polyamide 1010.

9. The polypropylene resin composition according to claim 1, wherein the dispersed phase (β) has a continuous phase (β1) containing the aliphatic polyamide resin (b2) and a finely dispersed phase (β2) containing the modified elastomer (b3) dispersed in the continuous phase (β1).

10. 10. The polypropylene resin composition according to any one of claims 1 to 9, wherein the content of the propylene polymer composition (a) is 50 to 94.9 parts by mass, the content of the polyolefin composition (b) is 5 to 49.9 parts by mass, and the content of the modified polypropylene (c) is 0.1 to 15 parts by mass (wherein the total content of the propylene polymer composition (a), the polyolefin composition (b), and the modified polypropylene (c) is 100 parts by mass).

11. 10. The polypropylene resin composition according to any one of claims 1 to 9, wherein the amount of the propylene polymer composition (a) is 50 to 94.9 parts by mass, the amount of the polyolefin composition (b) is 5 to 49.9 parts by mass, and the amount of the modified polypropylene (c) is 0.1 to 5 parts by mass (wherein the total amount of the propylene polymer composition (a), the polyolefin composition (b), and the modified polypropylene (c) is 100 parts by mass).

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