Propylene-based resin composition and its uses

Abstract

To provide a propylene-based resin composition from which a molding that contains a waste material derived from a food packaging material and is excellent in impact resistance is obtained.SOLUTION: A propylene-based resin composition contains 1-90 pts.mass of a polypropylene-based recycled resin (A) containing a waste material derived from a food packaging material, 10-99 pts.mass of a propylene-based polymer (B), 0-40 pts.mass of an ethylene-α-olefin copolymer (C), and 0-40 pts.mass of an inorganic filler (D) (provided that the total amount of the components (A), (B), (C) and (D) is 100 pts.mass.).SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a propylene-based resin composition containing waste material derived from food packaging materials. [Background technology]

[0002] In response to recent global environmental issues such as global warming, the so-called 3Rs (Reduce: reducing the amount of waste, Reuse: reusing things instead of throwing them away, and Recycle: returning used items to resources and making new products) have been proposed.

[0003] As a method for reusing waste materials (waste), various methods for reusing specific industrial waste materials have been proposed, such as a method for reusing waste materials generated from automobiles and buildings (Patent Document 1) and a method for reusing absorbent articles (Patent Document 2).

[0004] On the other hand, a method has been proposed to make it easier to reuse plastic waste, in which the plastic waste is crushed into small pieces, heated and melted to form small granules, then atomized, and the resulting granules are extruded into pellets for recycling (Patent Document 3).

[0005] With the enactment of the Containers and Packaging Recycling Law, discarded and collected plastic containers and packaging materials are attracting attention as a resource that can be used to reduce costs and ensure a stable supply of raw materials. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Publication No. 7-204619 [Patent Document 2] Patent Publication No. 2021-20437 [Patent Document 3] Japanese Patent Application Laid-Open No. 2004-25734 Summary of the Invention [Problem to be solved by the invention]

[0007] However, molded articles obtained from compositions containing waste materials derived from food packaging materials do not have sufficient impact resistance, and therefore their reuse applications are limited. An object of the present invention is to develop a propylene-based resin composition that contains waste materials derived from food packaging and that can give molded articles having excellent impact resistance. [Means for solving the problem]

[0008] The present invention relates to the following [1] to [6]. [1] A propylene-based resin composition comprising 1 to 90 parts by mass of a polypropylene-based recycled resin (A) containing waste food packaging materials, 10 to 99 parts by mass of a propylene-based polymer (B), 0 to 40 parts by mass of an ethylene-α-olefin copolymer (C), and 0 to 40 parts by mass of an inorganic filler (D) (wherein the total amount of components (A), (B), (C), and (D) is 100 parts by mass).

[0009] [2] Item [1] The propylene-based resin composition according to item [1], wherein the polypropylene-based recycled resin (A) containing waste materials derived from food packaging materials is a polypropylene-based recycled resin containing waste materials derived from logistics materials.

[0010] [3] Item [1] or [2]. The propylene resin composition according to Item [1] or [2], wherein the propylene polymer (B) comprises 70 to 100 mass% of a propylene polymer (b-1) having a melt flow rate (MFR, 230°C, load 2.16 kg) of 10 to 300 g / 10 min as measured in accordance with JIS K 7210, a content of structural units derived from propylene of 98 to 100 mol% and a content of structural units derived from at least one α-olefin selected from ethylene and an α-olefin having 4 to 8 carbon atoms of 0 to 2 mol%, and 0 to 30 mass% of a propylene-ethylene copolymer (b-2) having an intrinsic viscosity [η] of 1.5 to 8 dl / g as measured in decalin at 135°C and a content of structural units derived from ethylene of 30 to 60 mol (wherein the total amount of (b-1) and (b-2) is taken as 100 mass%).

[0011] [4] The propylene-based resin composition according to any one of items [1] to [3], wherein the propylene-based resin composition is a composition for automobile parts.

[0012] [5] A molded article made of the propylene-based resin composition according to any one of items [1] to [4]. [6] The molded article according to item [5], wherein the molded article is an automobile part. [Effects of the Invention]

[0013] The propylene-based resin composition of the present invention has excellent impact resistance and can be used in a variety of applications including automobile parts. DETAILED DESCRIPTION OF THE INVENTION

[0014] The present invention will be described in detail below. <Recycled polypropylene resin (A) containing waste materials from food packaging> One of the components contained in the propylene-based resin composition of the present invention, polypropylene-based recycled resin (A) containing waste material derived from food packaging (hereinafter, sometimes abbreviated as "recycled resin (A)"), is a polypropylene-based recycled resin containing waste material derived from food packaging, and is a composition obtained by melt-kneading a raw material obtained by recycling waste material derived from food packaging with a polypropylene resin.

[0015] The recycled resin (A) according to the present invention usually has a melt flow rate (MFR) measured in accordance with JIS K 7210 at a temperature of 230°C under a load of 2.16 kg in the range of 0.05 to 300 g / 10 min, preferably 0.1 to 250 g / 10 min, and more preferably 0.15 to 200 g / 10 min.

[0016] The recycled resin (A) according to the present invention may contain other plastic waste materials, such as waste materials derived from logistics materials, such as pallets, as long as it contains waste materials derived from food packaging.

[0017] More specifically, examples of the recycled resin (A) according to the present invention include recycled resins containing waste materials derived from food packaging, and recycled resins containing waste materials derived from food packaging and waste materials derived from logistics materials.

[0018] As the recycled resin (A) according to the present invention, for example, resins manufactured and sold by Taisei Resin Co., Ltd. under the trade names PP-N412 and PP-Z9A can be used. When these recycled resins (A) are used, a composition having excellent impact resistance can be obtained.

[0019] <Propylene polymer (B)> The propylene polymer (B), which is one of the components contained in the propylene resin composition of the present invention, is preferably a propylene polymer that satisfies the following requirement (b1). [Requirement (b1)] The melt flow rate (MFR), measured in accordance with JIS K 7210 at a temperature of 230°C and a load of 2.16 kg, is in the range of 1 to 200 g / 10 min, with the lower limit preferably being 3 g / 10 min, more preferably 5 g / 10 min, and the upper limit preferably being 150 g / 10 min, more preferably 100 g / 10 min.

[0020] The propylene polymer (B) according to the present invention is a homopolymer of propylene or a copolymer of propylene and an α-olefin. The copolymer of propylene and an α-olefin may be a random copolymer or a block copolymer.

[0021] The propylene polymer (B) according to the present invention is more preferably a so-called block copolymer comprising 70 to 100 mass% of a propylene polymer (b-1) having an MFR in the range of 10 to 300 g / 10 min, a content of propylene-derived structural units of 98 to 100 mol%, and a content of structural units derived from at least one α-olefin selected from ethylene and an α-olefin having 4 to 8 carbon atoms in the range of 0 to 2 mol%, and 0 to 30 mass% of a propylene-ethylene copolymer (b-2) having an intrinsic viscosity [η] measured in decalin at 135°C in the range of 1.5 to 8 dl / g and a content of ethylene-derived structural units of 30 to 60 mol%, preferably 30 to 50 mol%, where the total amount of (b-1) and (b-2) is taken as 100 mass%.

[0022] The propylene polymer (B) according to the present invention can be produced by various known methods. Specifically, when the propylene polymer (B) contains only the propylene polymer (b-1), a propylene homopolymer can be obtained by homopolymerizing propylene, or, if necessary, polymerizing propylene together with a small amount of an α-olefin, in the presence of a known olefin polymerization catalyst. Specific examples of the olefin polymerization catalyst include titanium catalysts and metallocene catalysts. Titanium catalysts are particularly preferred.

[0023] <Ethylene-α-olefin copolymer (C)> The ethylene-α-olefin copolymer (C), which is one of the components contained in the propylene-based resin composition of the present invention, is a copolymer mainly composed of ethylene, having a melt flow rate (MFR) measured in accordance with JIS K 7210 at a temperature of 230°C under a load of 2.16 kg in the range of 0.01 to 50 g / 10 min, preferably 0.05 to 40 g / 10 min, and more preferably 0.1 to 30 g / 10 min.

[0024] The ethylene-α-olefin copolymer (C) according to the present invention preferably has a density of 0.85 to 0.98 g / cm 3 , more preferably 0.85 to 0.95 g / cm 3 , and more preferably 0.86 to 0.90 g / cm 3 is in the range.

[0025] The ethylene-α-olefin copolymer (C) according to the present invention is a copolymer of ethylene and an α-olefin, and is generally an ethylene-based polymer known as linear low-density polyethylene (LLDPE), medium-density polyethylene (MDPE), or high-density polyethylene (HDPE), or an amorphous or low-crystalline ethylene-α-olefin copolymer, and is a copolymer mainly composed of ethylene.

[0026] The α-olefin copolymerized with ethylene is preferably an α-olefin having 3 to 20 carbon atoms, specifically propylene, 1-butene, 4-methyl-1-pentene-1, 1-hexene, 1-heptene, 1-octene, 1-nonene, 1-decene, 1-undecene, 1-dodecene, 1-tridecene, 1-tetradecene, 1-pentadecene, 1-hexadecene, 1-heptadecene, 1-nonadecene, 1-eicosene, 9-methyl-1-decene, 11-methyl-1-dodecene, and 12-ethyl-1-tetradecene. Among these α-olefins, 1-butene and 1-octene are particularly preferred. These α-olefins may be used alone or in combination of two or more.

[0027] The ethylene-α-olefin copolymer (C) according to the present invention can be used alone or in combination of two or more different ethylene copolymers. The ethylene-α-olefin copolymer (C) according to the present invention can be produced by various known production methods.

[0028] <Inorganic filler (D)> The inorganic filler (D), which is one of the components contained in the propylene-based resin composition of the present invention, is an inorganic filler known as an additive for rubber and plastics, and examples thereof include aluminum-based fillers (aluminum hydroxide, aluminum silicate), barium-based fillers (barium hydroxide, barium carbonate), calcium-based fillers (calcium carbonate, calcium silicate, calcium sulfate), magnesium-based fillers (magnesium carbonate, magnesia, magnesium silicate, talc), silica-based fillers (silica, sodium aluminum silicate), zinc-based fillers (zinc oxide), bentonite, clay, and diatomaceous earth.

[0029] <Propylene-based resin composition> The propylene-based resin composition of the present invention contains 1 to 90 parts by mass, preferably 5 to 90 parts by mass, and more preferably 10 to 90 parts by mass of the recycled resin (A), 10 to 99 parts by mass, preferably 10 to 95 parts by mass, and more preferably 10 to 90 parts by mass of the propylene-based polymer (B), 0 to 40 parts by mass, preferably 0 to 35 parts by mass, and more preferably 0 to 30 parts by mass of the ethylene-α-olefin copolymer (C), and 0 to 40 parts by mass, preferably 0 to 35 parts by mass, and more preferably 0 to 30 parts by mass of the inorganic filler (D) (wherein the total amount of components (A), (B), (C), and (D) is 100 parts by mass).

[0030] The propylene resin composition of the present invention contains the propylene polymer (B) in addition to the recycled resin (A), and therefore a molded article obtained from the composition has excellent impact resistance. The propylene-based resin composition of the present invention may contain various additives as needed, provided that the purpose of the composition is not impaired. Examples of additives include nucleating agents, antioxidants, hydrochloric acid absorbers, heat stabilizers, weather stabilizers, light stabilizers, ultraviolet absorbers, lubricants, antistatic agents, flame retardants, pigments, dyes, dispersants, copper inhibitors, neutralizing agents, plasticizers, crosslinking agents, flow improvers such as peroxides, weld strength improvers, natural oils, synthetic oils, and waxes. These additives may be used alone or in combination of two or more.

[0031] <<Method for producing propylene-based resin composition>> The propylene-based resin composition of the present invention can be produced by various known production methods, for example, by mixing the recycled resin (A), the propylene-based polymer (B), the ethylene-α-olefin copolymer (C), and the inorganic filler (D) in predetermined amounts by a conventional method such as dry blending or melt-kneading in an extruder.

[0032] <<Molded article made of propylene-based resin composition>> The molded article of the present invention is characterized by containing the above-mentioned propylene-based resin composition of the present invention. Specific examples thereof include those obtained by extrusion molding, compression molding, or injection molding of the propylene-based resin composition of the present invention. Among these molded articles, injection-molded articles are preferred.

[0033] <<Uses of the Propylene-Based Resin Composition>> The propylene-based resin composition and molded article of the present invention can be used for logistics purposes such as automobile parts, containers, home appliance parts, housing equipment, daily necessities, containers, pallets, etc.

[0034] In particular, it can be suitably used for automobile interior and exterior components such as door panels, pillar trims, door trims, door lower garnishes, instrument panels, and bumpers, and automobile parts such as engine room peripheral parts. [Example]

[0035] The present invention will be described in more detail below with reference to examples, although the present invention is not limited to these examples. The polymers used in the examples and comparative examples are shown below. (1) Polypropylene-based recycled resin containing waste materials from food packaging (A) (1-1) Polypropylene-based recycled resin made from waste food packaging (A-1): Taisei Resin Co., Ltd. Product name: PP-N412 MFR: 6g / 10min. (1-2) Polypropylene-based recycled resin (A-2) made from waste materials derived from food packaging and logistics materials: Taisei Resin Co., Ltd. Product name: PP-Z9A MFR: 6g / 10min.

[0036] (2) Propylene polymer (B) (2-1) Propylene polymer (B-1): MFR: 12 g / 10 min. Propylene polymer (b-1-1): 89 parts by mass. MFR: 18 g / 10 min. Content of structural units derived from propylene: 99.9 mol%. Propylene-ethylene copolymer (b-1-2): 11 parts by mass. Intrinsic viscosity [η]: 2.8 dl / g, content of structural units derived from ethylene: 39 mol%. (2-2) Propylene polymer (B-2): MFR: 30 g / 10 min. Propylene polymer (b-2-1): 89 parts by mass. MFR: 46 g / 10 min. Content of structural units derived from propylene: 99.9 mol%. Propylene-ethylene copolymer (b-2-2): 11 parts by mass. Intrinsic viscosity [η]: 2.8 dl / g, content of structural units derived from ethylene: 30 mol%. (2-3) Propylene polymer (B-3): MFR: 30 g / 10 min. Propylene polymer (b-3-1): >99.5 parts by mass. MFR: 30 g / 10 min. Content of structural units derived from propylene: 99.9 mol%. (2-4) Propylene polymer (B-4): MFR: 30 g / 10 min. Propylene polymer (b-4-1): 76.5 parts by mass. MFR: 93 g / 10 min. Content of structural units derived from propylene: 99.9 mol%. Propylene-ethylene copolymer (b-4-2): 23.5 parts by mass. Intrinsic viscosity [η]: 2.5 dl / g, content of structural units derived from ethylene: 39 mol%. (2-5) Propylene polymer (B-5): MFR: 50 g / 10 min. Propylene polymer (b-5-1): 76.5 parts by mass. MFR: 213 g / 10 min. Content of structural units derived from propylene: 99.9 mol%. Propylene-ethylene copolymer (b-5-2): 23.5 parts by mass. Intrinsic viscosity [η]: 2.5 dl / g, content of structural units derived from ethylene: 39 mol%. Propylene-ethylene copolymer (b-6-2): 23.5 parts by mass. Intrinsic viscosity [η]: 2.5 dl / g, content of structural units derived from ethylene: 39 mol%.

[0037] (3) Ethylene-α-olefin copolymer (C) (3-1) Ethylene-1-octene copolymer (C-1) MFR: 2.0 g / 10 min, content of structural units derived from ethylene: 80 mol% (manufactured by Dow, product name ENGAGE TM 8100

[0038] (4) Inorganic filler (D) (4-1) Talc (Asada Flour Milling Co., Ltd., trade name JM-209, D50=3.9±0.4 μm) was used (D-1). The physical properties of the propylene-based resin compositions obtained in the examples and comparative examples were measured by the following methods.

[0039] [Charpy impact test] Charpy impact strength (kJ / m) at a test temperature of 23°C in accordance with ISO 179 2 ) (with notch) was measured.

[0040] [Flexural modulus] The flexural modulus (MPa) was measured in accordance with ISO 178 at a test temperature of 23°C and a test speed of 30 mm / min.

[0041] [MFR (Melt Flow Rate)] The melt flow rate (MFR) was measured in accordance with JIS K 7210 at 230°C under a load of 2.16 kg.

[0042] [specific gravity] Measurements were made in accordance with ISO 1183.

[0043] Example 1 A polypropylene-based recycled resin (A-1) containing waste material from food packaging: 15 parts by mass, a propylene-based polymer (B-1): 55 parts by mass, and a propylene-based polymer (B-2): 30 parts by mass were dry-blended, and then melt-extruded at 200°C using an extruder to obtain a propylene-based resin composition. The physical properties of the resulting propylene-based resin composition were measured by the methods described above. The results are shown in Table 1.

[0044] Examples 2 to 8 A propylene-based resin composition was obtained in the same manner as in Example 1, except that the type and blending amount of polypropylene-based recycled resin (A) containing waste material derived from food packaging materials shown in Table 1 were used instead of the propylene-based resin composition used in Example 1. The physical properties of the obtained propylene-based resin composition were measured by the methods described above. The results are shown in Table 1.

[0045] [Reference Example 1 and Comparative Example 1] A propylene-based resin composition was obtained in the same manner as in Example 1, except that a polypropylene-based recycled resin (A) containing waste material derived from food packaging and its blending amount were used instead of the propylene-based resin composition used in Example 1. The physical properties of the obtained propylene-based resin composition were measured by the methods described above. The results are shown in Table 1.

[0046] [Table 1]

[0047] As shown in Table 1, the propylene-based resin compositions (Examples 1 to 8) containing the polypropylene-based recycled resin (A) made from waste materials derived from food packaging materials of the present invention have superior impact resistance compared to a composition (Comparative Example 1) consisting only of the polypropylene-based recycled resin (A) containing waste materials derived from food packaging materials.

[0048] Furthermore, the propylene-based resin compositions according to the present invention (Examples 1 to 8) have impact strength equivalent to or greater than that of a composition not containing the polypropylene-based recycled resin (A) (Reference Example 1), and are therefore compositions that meet the so-called 3Rs.

Claims

1. The content of polypropylene-based recycled resin (A) containing waste materials derived from food packaging is 15 to 50 parts by mass, the content of propylene-based polymer (B) (excluding recycled products) is 50 to 85 parts by mass, the content of ethylene-α-olefin copolymer (C) is 0 to 5 parts by mass, and the content of inorganic filler (D) is 0 to 10 parts by mass (where the total amount of components (A), (B), (C), and (D) is 100 parts by mass), a melt flow rate (MFR, 230°C, load 2.16 kg) measured in accordance with JIS K 7210 of 10 to 30 g / 10 min; a content of propylene polymer (b-1) having 98 to 100 mol% of structural units derived from propylene and 0 to 2 mol% of structural units derived from at least one α-olefin selected from ethylene and an α-olefin having 4 to 8 carbon atoms of 70 to 100 mass%; an intrinsic viscosity [η] measured in decalin at 135°C of 1.5 to 8 dl / g; and a content of propylene-ethylene copolymer (b-2) having 30 to 60 mol% of structural units derived from ethylene of 0 to 30 mass% (wherein the total amount of (b-1) and (b-2) is taken as 100 mass%).

2. The propylene-based resin composition according to claim 1, wherein the polypropylene-based recycled resin (A) containing waste materials derived from food packaging materials further contains waste materials derived from logistics materials.

3. The propylene resin composition according to claim 1 or 2, wherein the propylene resin composition is a composition for automotive parts.

4. A molded article comprising the propylene resin composition according to any one of claims 1 to 3.

5. The molded body according to claim 4, wherein the molded body is an automobile part.

Images