Polyolefin composition and molded article thereof

Abstract

To provide a polyolefin composition which can reduce an environmental load and can obtain a molded article having excellent mechanical properties.SOLUTION: There is provided a polyolefin composition using modified lignin obtained by acid-catalyzed solvolysis of a wood raw material using a glycol such as polyethylene glycol as a solvent and an olefin-based polymer having a hydroxyl group and a reactive moiety having reactivity. Specifically, there is provided a polyolefin composition which comprises (A) 10 to 60 mass% of glycol lignin and (B) 40 to 90 mass% of an olefin-based polymer, wherein the olefin-based polymer (B) has a hydroxyl group and a reactive moiety having reactivity.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a polyolefin composition and a molded article thereof. [Background technology]

[0002] The use of lightweight plastics and their composite materials as components of automobiles is increasing, and their usage rate in automobiles is becoming large. However, petroleum-derived plastics such as polypropylene have been problematic in that they cause environmental burdens such as waste.

[0003] Therefore, research has begun into lightweight components that use biomass materials such as lignin instead of petroleum-derived plastics (see Patent Documents 1 to 3). Lignin is a component that accounts for 20 to 30% of wood and is obtained in large quantities from thinned wood and paper manufacturing processes.

[0004] Patent Document 1 describes a thermoplastic resin composition containing (A) 99 to 50% by mass of a thermoplastic resin and (B) 50 to 1% by mass of lignin acetate. The lignin acetate described in Patent Document 1 is an acetylated lignin, and it is said that by incorporating this in a thermoplastic resin to form a composition, it is possible to obtain a composition that reduces the burden on the environment, has high flame retardancy, and is excellent in the appearance of the molded article, heat aging resistance, and weather resistance, and a molded article thereof.

[0005] Patent Document 2 describes a resin composition containing a thermoplastic resin, wood material powder, and a compatibilizer having affinity for the thermoplastic resin and the cellulose in the wood material powder, and describes that processed wood powder from which at least essential oil components have been removed and lignin remains can be used as the wood material powder. According to Patent Document 2, it is possible to use as much wood powder or processed wood powder as possible without reducing the physical properties such as strength and moldability of the resulting molded product, which promotes the effective use of unused materials (wood biomass) and provides a resin composition that ensures flame retardancy.

[0006] Patent Document 3 describes an antibacterial resin composition containing lignin and a thermoplastic resin, in which the lignin is soluble in an organic solvent and contains 0.01 to 50 mass% of lignin as a non-volatile content. According to Patent Document 3, it is said that an antibacterial resin composition can be obtained using lignin, which is a plant-derived component that is highly safe for the human body and has excellent antibacterial properties. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] International Publication No. 2016 / 104634 [Patent Document 2] JP 2014-133835 A [Patent Document 3] JP 2011-219716 A Summary of the Invention [Problem to be solved by the invention]

[0008] Conventional industrial lignins such as acetic acid lignin have low affinity with petroleum-derived resins, and may not be uniformly dispersed in the resin, but may exist as aggregates in the resin. For this reason, molded articles obtained from compositions containing industrial lignin are still insufficient in terms of mechanical properties and appearance, and further improvements are required.

[0009] The present invention has been made in consideration of the above circumstances, and aims to provide a polyolefin composition and a molded article thereof that reduce the burden on the environment by using biomass-derived lignin instead of petroleum-derived plastics, and at the same time, have sufficient mechanical properties. [Means for solving the problem]

[0010] The present inventors have conducted extensive research to solve the above problems, and have found that a polyolefin composition using modified lignin obtained by acid solvolysis of wood raw material using a glycol such as polyethylene glycol as a solvent and an olefin polymer having a reactive site reactive with a hydroxyl group can provide a composition that is excellent in mechanical properties while reducing the environmental load, thereby completing the present invention.

[0011] That is, the present invention includes the following aspects. [1] A polyolefin composition comprising (A) 10 to 60 mass% of glycol lignin and (B) 40 to 90 mass% of an olefin polymer, The polyolefin composition, wherein the (B) olefin polymer has a reactive site reactive with a hydroxyl group. [2] The polyolefin composition according to aspect [1], wherein the (A) glycol lignin is a modified lignin chemically modified with at least one glycol selected from the group consisting of ethylene glycol, propylene glycol, polyethylene glycol, polypropylene glycol, polyethylene polypropylene glycol, glycerin, and polyglycerin. [3] The polyolefin composition according to aspect [2], wherein the glycol is a polyethylene glycol having a weight average molecular weight of 100 to 2,000. [4] The polyolefin composition according to any one of aspects [1] to [3], wherein the (B) olefin-based polymer is a thermoplastic resin or a thermoplastic elastomer. [5] The polyolefin composition according to any one of aspects [1] to [4], wherein the reactive site is at least one group selected from the group consisting of a carboxy group, a carboxy anhydride group, a glycidyl group, and an acrylate ester group, and / or a modified site with an unsaturated carboxylic acid or acid anhydride. [6] The polyolefin composition according to any one of aspects [1] to [5], wherein the (B) olefin polymer is a maleic anhydride modified polyolefin resin. [7] The polyolefin composition according to any one of embodiments [1] to [6], further comprising (C) a reinforcing filler. [8] The polyolefin composition according to aspect [7], wherein the (C) reinforcing filler is at least one selected from the group consisting of glass fiber, glass flake, carbon fiber, graphite, carbon nanotube, graphene, molybdenum disulfide, wollastonite, mica, talc, pyrophyllite, smectite, imogolite, potassium titanate fiber, layered titanate, calcium silicate, aramid fiber, cellulose fiber, cellulose nanofiber, and zirconium phosphate. [9] A molded article of the polyolefin composition according to any one of aspects [1] to [8]. Effect of the Invention

[0012] According to the polyolefin composition of the present disclosure, it is possible to reduce the environmental impact and to obtain a molded article having excellent mechanical properties. [Brief description of the drawings]

[0013] [Figure 1] 1 is a scanning electron microscope photograph of the dumbbell test piece of Example 14. [Diagram 2] 1 is a scanning electron microscope photograph of a dumbbell test piece of Comparative Example 6. [Diagram 3] 1 is a stress-strain curve obtained for the dumbbell test specimen of Example 14. [Figure 4] 1 is a stress-strain curve obtained for the dumbbell test piece of Comparative Example 1. [Diagram 5] 1 is a stress-strain curve obtained for the dumbbell test piece of Comparative Example 6. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] Hereinafter, the embodiments of the present invention will be described, but the present invention is not limited to the following embodiments. Furthermore, among the components in the following embodiments, components that are not described in the claims showing the highest concept will be described as optional components.

[0015] <Polyolefin composition> The polyolefin composition of the present disclosure contains 10 to 60 mass % of (A) glycol lignin and 40 to 90 mass % of (B) an olefin polymer, and the (B) olefin polymer has a reactive site reactive with a hydroxyl group.

[0016] The polyolefin composition of the present disclosure can be produced by mixing the raw materials that make up the composition by a general mixing process using a twin-screw extruder or the like.

[0017] <(A) Glycol lignin> The (A) glycol lignin, which is an essential component of the polyolefin composition of the present disclosure, is a modified lignin obtained by solvolysis (acid solvolysis) of lignocellulose, a wood raw material, in the presence of an acid catalyst using glycol as a solvent. Lignocellulose is the main component of woody or herbaceous biomass, and is composed of polysaccharide polymers such as cellulose and hemicellulose, and lignin, a phenolic polymer.

[0018] The method for producing glycol lignin (A) from lignocellulose is not particularly limited, and any known method can be applied. For example, glycol lignin can be produced by the method disclosed in JP 2017-197517 A.

[0019] For example, cedar wood flour, which is lignocellulose, is subjected to an acid solvolysis treatment by heating in the presence of an acid catalyst using glycol as a solvent, and the solution is made alkaline. After that, the pulp residue fraction, the main components of which are cellulose and hemicellulose, is separated to obtain a soluble fraction. The obtained soluble fraction is then returned to an acidic state, and the resulting precipitate is separated, washed, and dried by a conventional method to obtain (A) glycol lignin. The (A) glycol lignin of the present disclosure is a modified lignin in which lignin is chemically modified with glycol used as a solvent in the acid solvolysis treatment.

[0020] The glycol used as a solvent in the acid solvolysis treatment is not particularly limited, and may be, for example, at least one selected from the group consisting of ethylene glycol, propylene glycol, polyethylene glycol, polypropylene glycol, polyethylene polypropylene glycol, glycerin, and polyglycerin.

[0021] When the glycol used as a solvent in the acid solvolysis treatment is polyethylene glycol, at least one ethyleneoxy group may be replaced with a propyleneoxy group, and when the glycol is polypropylene glycol, at least one propyleneoxy group may be replaced with an ethyleneoxy group.

[0022] When the glycol used as a solvent in the acid solvolysis treatment is a polymer such as polyethylene glycol, polypropylene glycol, polyethylene polypropylene glycol, or polyglycerin, the molecular weight of the polymer can be appropriately selected depending on the thermal melting property of the glycol lignin (A) to be obtained, etc. For example, in the case of polyethylene glycol, the weight average molecular weight may be 100 to 2000, and more preferably 200 to 600.

[0023] The amount of glycol used as a solvent in the acid solvolysis treatment is not particularly limited, but is, for example, preferably 2 to 10 parts by mass, more preferably 3 to 6 parts by mass, per part by mass of lignocellulose.

[0024] The content of (A) glycol lignin in the polyolefin composition of the present disclosure is 10 to 60 mass% of the entire polyolefin composition. If it is 10 mass% or more, it is possible to obtain a composition having excellent mechanical properties while exerting the effect of reducing the environmental load. On the other hand, if it is 60 mass% or less, the material containing (A) glycol lignin and (B) olefin polymer can be sufficiently kneaded by a general-purpose kneader.

[0025] The content of (A) glycol lignin in the polyolefin composition of the present disclosure may be 15 mass% or more, 20 mass% or more, 25 mass% or more, 30 mass% or more, 35 mass% or more, or 40 mass% or more, and may be 55 mass% or less, 50 mass% or less, 45 mass% or less, 40 mass% or less, 35 mass% or less, or 30 mass% or less, based on the entire polyolefin composition.

[0026] <(B) Olefin-based polymer> The olefin polymer (B), which is an essential component of the polyolefin composition of the present disclosure, is a polymer of one or more α-olefins and has a reactive site reactive with a hydroxyl group. The carbon number of the α-olefin serving as a monomer for the olefin polymer (B) is not particularly limited, but is preferably in the range of 2 to 18.

[0027] The olefin polymer (B) contained in the polyolefin composition of the present disclosure may be a thermoplastic resin or a thermoplastic elastomer. Alternatively, the polyolefin composition of the present disclosure may contain both of these.

[0028] Examples of the α-olefins constituting the (B) olefin-based polymer include ethylene, propylene, butene-1, pentene-1, 2-methylbutene-1, 3-methylbutene-1, hexene-1, 3-methylpentene-1, 4-methylpentene-1, 3,3-dimethylbutene-1, heptene-1, methylhexene-1, dimethylpentene-1, trimethylbutene-1, ethylpentene-1, octene-1, methylpentene-1, dimethylhexene-1, trimethylbutene-1, ethylpentene-1, octene-1, methylpentene-1, dimethylhexene-1, trimethylbutene-1, ethylpentene-1, octene-1, methylpentene-1, dimethylhexene-1, trimethylpent ...octene-1, methylpentene-1, ethylhexene-1, octene-1, octene-1, octene-1, Examples of the α-olefins include 1-pentene, ethylhexene, 1-methylethylpentene, 1-diethylbutene, 1-propylpentene, 1-decene, 1-methylnonene, 1-dimethyloctene, 1-trimethylheptene, 1-ethyloctene, 1-methylethylheptene, 1-diethylhexene, 1-octadecene, 1-dodecene, and 1-hexadodecene. The olefin polymer (B) may be a homopolymer or a copolymer of these α-olefins.

[0029] Preferred examples of the polymer include polymers containing ethylene as a main component, polymers containing propylene as a main component, polymers containing butene as a main component, and polymers containing 4-methylpentene-1 as a main component.

[0030] More preferred examples of the polymer include propylene homopolymer, propylene-ethylene random copolymer, propylene-butene random copolymer, propylene-ethylene-butene random copolymer, butene homopolymer, butene-ethylene random copolymer, butene-propylene random copolymer, butene-ethylene-propylene random copolymer, 4-methylpentene-1 homopolymer, 4-methylpentene-1 and propylene random copolymer, 4-methylpentene-1 and hexene-1 random copolymer, 4-methylpentene-1 and decene-1 random copolymer, 4-methylpentene-1 and tetradecene random copolymer, 4-methylpentene-1 and hexadecene-1 random copolymer, 4-methylpentene-1 and octadecene-1 random copolymer, and 4-methylpentene-1, hexadecene-1 and octadecene-1 random copolymer.

[0031] In particular, polymers containing propylene as a main component are preferred because of their excellent mechanical properties, and among these, propylene homopolymers and propylene-ethylene random copolymers are particularly preferred.

[0032] The reactive site reactive with the hydroxyl group of the (B) olefin polymer becomes a site reactive with the hydroxyl group of the (A) glycol lignin. The reaction between the hydroxyl group of the (A) glycol lignin and the reactive site reactive with the hydroxyl group of the (B) olefin polymer improves the mechanical properties of the polyolefin composition of the present disclosure, such as tensile strength and tensile modulus. In addition, when the polyolefin composition of the present disclosure contains a (C) reinforcing filler described below, the interface with the (C) reinforcing filler is reinforced by this reaction. As a result, the mechanical properties of the polyolefin composition of the present disclosure can be further improved.

[0033] The reactive site reactive with the hydroxyl group of the (B) olefin polymer is not particularly limited as long as it reacts with the hydroxyl group. For example, it may be at least one group selected from the group consisting of a carboxy group, a carboxy anhydride group, a glycidyl group, and a (meth)acrylic acid ester group, and a modified site with an unsaturated carboxylic acid or an acid anhydride. The reactive site reactive with the hydroxyl group of the (B) olefin polymer in the present disclosure may be not only one type, but also two or more types.

[0034] The content of reactive sites in the (B) olefin polymer is preferably 0.01 to 5 mass%, more preferably 0.05 to 3.5 mass%, calculated as the structural units forming the reactive sites relative to the structural units of the entire (B) olefin polymer. When the content of reactive sites is within this range, a polyolefin composition having improved mechanical strength can be obtained by reaction with the (A) glycol lignin.

[0035] The method for forming the reactive site in the olefin polymer (B) is not particularly limited. For example, a compound having a carboxy group, a carboxy anhydride group, a glycidyl group, a (meth)acrylic acid ester group, or the like may be added as a comonomer when polymerizing the olefin polymer (B) to be copolymerized.

[0036] Alternatively, when the reactive site in the (B) olefin-based polymer is an unsaturated carboxylic acid or an acid anhydride, these may be graft-polymerized onto the olefin-based polymer. The grafting method is not particularly limited, and a conventionally known graft polymerization method such as a solution method or a melt-kneading method can be adopted. For example, there is a method in which a polyolefin is melted, an unsaturated carboxylic acid and / or an acid anhydride is added thereto for graft reaction, or a method in which a polyolefin is dissolved in a solvent to prepare a solution, an unsaturated carboxylic acid and / or an acid anhydride is added thereto for graft reaction, and the like.

[0037] In order to adjust the content of reactive sites, an olefin having a reactive site and an olefin not having a reactive site may be appropriately mixed.

[0038] The unsaturated carboxylic acid or acid anhydride is not particularly limited, but may be, for example, an unsaturated compound having one or more carboxylic acid groups, an ester of a compound having a carboxylic acid group and an alkyl alcohol, or an unsaturated compound having one or more carboxylic acid anhydride groups. Examples of the unsaturated group of the unsaturated compound include a vinyl group, a vinylene group, and an unsaturated cyclic hydrocarbon group. The unsaturated carboxylic acid and / or acid anhydride may be used alone or in combination of two or more.

[0039] Among these, unsaturated dicarboxylic acids or their acid anhydrides are preferred, and maleic acid, nadic acid, or their acid anhydrides are more preferred. In particular, the olefin polymer (B) of the present disclosure is most preferably a maleic anhydride-modified polyolefin resin.

[0040] The content of the olefin polymer (B) in the polyolefin composition of the present disclosure is 40 to 90 mass% of the entire polyolefin composition. If it is 90 mass% or less, it is possible to obtain a composition having excellent mechanical properties while exerting the effect of reducing the environmental load. On the other hand, if it is 40 mass% or more, the material containing the glycol lignin (A) and the olefin polymer (B) can be sufficiently kneaded by a general-purpose kneader.

[0041] The content of the (B) olefin-based polymer in the polyolefin composition of the present disclosure may be 45 mass% or more, 50 mass% or more, 55 mass% or more, 60 mass% or more, 65 mass% or more, or 70 mass% or more, and may be 85 mass% or less, 80 mass% or less, 75 mass% or less, 70 mass% or less, 65 mass% or less, or 60 mass% or less, based on the entire polyolefin composition.

[0042] <(C) Reinforcing filler> The polyolefin composition of the present disclosure may contain a reinforcing filler (C) as an optional component. In the polyolefin composition of the present disclosure, the interface between the glycol lignin (A) and the olefin polymer (B) and the reinforcing filler (C) is reinforced due to a synergistic effect caused by the reaction between the glycol lignin and the olefin polymer (B). As a result, the polyolefin composition of the present disclosure can significantly improve mechanical properties such as tensile strength and tensile modulus by containing the reinforcing filler (C).

[0043] The (C) reinforcing filler is not particularly limited as long as it improves the tensile strength and tensile modulus of a molded article formed from the polyolefin composition of the present disclosure, and may be, for example, at least one type selected from the group consisting of glass fiber, glass flake, carbon fiber, graphite, carbon nanotube, graphene, molybdenum disulfide, wollastonite, mica, talc, pyrophyllite, smectite, imogolite, potassium titanate fiber, layered titanate, calcium silicate, aramid fiber, cellulose fiber, cellulose nanofiber, and zirconium phosphate.

[0044] The aspect ratio (x / z) of the (C) reinforcing filler is not particularly limited, but is preferably 10 or more. With an aspect ratio of 10 or more, the mechanical strength of the resulting polyolefin composition can be further increased. Here, the "x" is the average value of the maximum dimensions of the individual fillers constituting the reinforcing filler (C), and the "z" is the average value of the minimum dimensions in the direction perpendicular to the maximum dimensions.

[0045] The content of the (C) reinforcing filler is not particularly limited, but is preferably 5 to 40 mass% of the total polyolefin composition. If the (C) reinforcing filler is contained in this range, the mechanical strength of the obtained polyolefin composition can be sufficiently increased.

[0046] The content of the (C) reinforcing filler in the polyolefin composition of the present disclosure may be 10 mass% or more, 15 mass% or more, 20 mass% or more, 25 mass% or more, or 30 mass% or more, and may be 35 mass% or less, 30 mass% or less, 25 mass% or less, 20 mass% or less, or 15 mass% or less, based on the entire polyolefin composition.

[0047] <Other ingredients> The polyolefin composition of the present disclosure may contain other components for the purpose of imparting various properties to the resulting composition, within the scope of not impairing the effects of the present invention. Examples of other components include resins and elastomers other than the (B) olefin polymer, various additives, etc.

[0048] Examples of additives include inorganic fillers such as talc, calcium carbonate, metal powder, titanium oxide, zinc oxide, etc. (excluding (C) reinforcing filler), colorants such as pigments and dyes, antioxidants, ultraviolet absorbers, light stabilizers, heat stabilizers, antistatic agents, crystal nucleating agents, dispersants, flame retardants, flame retardant assistants, plasticizers, etc. The content of additives in the polyolefin composition is not particularly limited, but is, for example, 0.01 to 30% by mass with respect to the entire polyolefin composition.

[0049] <Molded body> The molded article of the present disclosure is a molded article obtained by molding the polyolefin composition of the present disclosure.

[0050] The molding method for obtaining the molded article is not particularly limited, and any method known as a molding method for polyolefins can be used, such as extrusion molding, injection molding, blow molding, extrusion blow molding, injection blow molding, press molding, vacuum molding, etc.

[0051] The molded article may be a molded article formed from the polyolefin composition of the present disclosure, or may be a molded article having a portion, such as a surface layer, formed from the polyolefin composition.

[0052] The applications of the molded article are not particularly limited, and the molded article can be used in a wide range of fields, such as home appliance material parts, communication device parts, electric parts, electronic parts, automobile parts, other vehicle parts, ship and aircraft materials, machine mechanism parts, building materials, civil engineering materials, agricultural materials, power tool parts, food containers, films, sheets, fibers, etc. EXAMPLES

[0053] The present invention will be described in detail below with reference to examples, but the present invention is not limited to these.

[0054] <Material> The materials of the polyolefin compositions used in the examples and comparative examples are as follows.

[0055] (A) Glycol lignin: derived from Japanese cedar lignin GL200: glycol lignin modified with polyethylene glycol of molecular weight 200 GL400: glycol lignin modified with polyethylene glycol of molecular weight 400 GL600: Glycol lignin modified with polyethylene glycol of molecular weight 600 (A') Industrial lignin: derived from bamboo lignin Acetic acid lignin (product name: Solvent Lignin, Guangzhou Yinnovator Biotech)

[0056] (B) Olefin polymer (B-1) Maleic anhydride-modified propylene homopolymer with a maleic anhydride content of 0.04% by mass and a MFR (melt flow rate) of 7 g / 10 min (product name: Admer (registered trademark) QE800, Mitsui Chemicals) (B-2) Maleic anhydride-modified polypropylene obtained by uniformly melt-kneading 95% by mass of a polypropylene homopolymer (trade name: PM900A, Sunallomer) with an MFR of 30 g / 10 min and 5% by mass of a maleic anhydride-modified polypropylene (trade name: UMEX 1001, Sanyo Chemical Industries) with an acid value of 26 at 200° C. using a twin-screw extruder.

[0057] (C) Reinforcement filler Carbon fiber (CF): Chopped carbon fiber with a fiber diameter of 7 μm and a length of 6 mm (aspect ratio (x / z) ≒ 850) (product name: Pyrofil (registered trademark) TR06NL, Mitsubishi Chemical) Glass fiber: Chopped glass fiber with fiber diameter of 13 μm and length of 3 mm (aspect ratio (x / z) ≒ 230) (product name: CS3PE944, Nittobo)

[0058] <Examples 1 to 22 and Comparative Examples 1 to 8> The materials having the compositions shown in Tables 1 to 3 were melt-kneaded in a twin-screw kneader (model: S1KRC, Kurimoto Iron Works) at a cylinder temperature of 230 to 250°C to produce pellets. Dumbbell test specimens (ISO 527-2) were molded from the dried pellets using a small injection molding machine (model: Mini JET II, ​​Thermo Fisher Scientific) at a cylinder temperature of 220 to 250°C and a mold temperature of 80°C.

[0059] Examples 1 to 10 are examples of compositions of (A) glycol lignin and (B) olefin-based polymer, Comparative Examples 1 and 3 are examples of only (B) olefin-based polymer, and Comparative Example 2 is an example of a composition of (A') industrial lignin and (B) olefin-based polymer. Examples 11 to 22 and Comparative Examples 4 to 8 are examples in which (C) reinforcing filler is further blended. Specifically, Examples 11 to 22 are examples of compositions of (A) glycol lignin, (B) olefin-based polymer, and (C) reinforcing filler, Comparative Example 4 is an example of a composition of (A') industrial lignin, (B) olefin-based polymer, and (C) reinforcing filler, and Comparative Examples 5 to 8 are examples of compositions of (B) olefin-based polymer and (C) reinforcing filler.

[0060] <Measurement> [Mechanical properties (tensile strength, tensile modulus)] The dumbbell test pieces prepared in Examples 1 to 22 and Comparative Examples 1 to 8 were subjected to tensile tests at a crosshead speed of 5 mm / min using an electromechanical testing machine (model: EZ-LX, Shimadzu Corporation) in accordance with ASTM D638 to evaluate the tensile strength and tensile modulus. The strain required to determine the tensile modulus was measured using a video extensometer. The tensile tests were performed for each dumbbell test piece with N=3, and the tensile strength and tensile modulus were averaged. The results are shown in Tables 1 to 3.

[0061] [Table 1]

[0062] [Table 2]

[0063] [Table 3]

[0064] Examples 1 to 10, which are compositions of (A) glycol lignin and (B) an olefin polymer, exhibited higher tensile strength and tensile modulus than Comparative Example 1 and Comparative Example 3, which consisted of only the olefin polymer (B). Moreover, Examples 2, 5, and 8, which contained 20 mass% of (A) glycol lignin, exhibited higher tensile strength and tensile modulus than Comparative Example 2, which contained 20 mass% of (A') acetic acid lignin, an industrial lignin.

[0065] Furthermore, Examples 14, 15, and 16, which contained 20 mass% of (A) glycol lignin and 20 mass% of (C) carbon fiber as a reinforcing filler, showed a significant reinforcing effect compared to Comparative Example 4, which contained 20 mass% of (A') acetic acid lignin, which is an industrial lignin, and 20 mass% of (C) carbon fiber as a reinforcing filler.

[0066] [Interface observation] For the dumbbell test pieces prepared in Example 14 and Comparative Example 6, the fracture surfaces of the dumbbell test pieces after the above-mentioned tensile tests were sputter-coated and analyzed using a scanning electron microscope (model: Quanta 600 SEM, FEI) under high vacuum with an acceleration voltage of 7.5 kV and a working distance of 10 mm. A scanning electron microscope photograph of the dumbbell test piece of Example 14 is shown in FIG. 1, and a scanning electron microscope photograph of the dumbbell test piece of Comparative Example 6 is shown in FIG. 2.

[0067] It can be seen from Fig. 1 that the interface between the (A) glycol lignin and the (C) reinforcing filler, carbon fiber, is strengthened as a result of the reaction between the hydroxyl group of the (A) glycol lignin and the reactive site of the hydroxyl group of the (B) olefin polymer. On the other hand, Fig. 2 shows that the interface between the (B) olefin polymer and the (C) reinforcing filler is not strengthened.

[0068] [Weather resistance test] The dumbbell test pieces prepared in Example 14, Comparative Example 1, and Comparative Example 6 were subjected to a 530 W / m2 test using a metal halide lamp in a metaling weather meter (model: MV2000, Suga Test Instruments Co., Ltd.). 2(300-400 nm), chamber temperature 37°C, humidity 10%, irradiation energy 100 MJ / m 2 , 300MJ / m 2 , 1000MJ / m 2 The dumbbell test pieces were irradiated for 52, 156, and 520 hours, respectively. The above-mentioned tensile tests were carried out on the dumbbell test pieces before and after irradiation. The tensile tests were carried out for each dumbbell test piece, N=3.

[0069] A typical stress-strain curve obtained for the dumbbell test piece of Example 14 is shown in Figure 3, and the stress-strain curves obtained for the dumbbell test pieces of Comparative Examples 1 and 6 are shown in Figures 4 and 5, respectively. Note that for Comparative Example 6 (Figure 5), the stress-strain curves are shown before and after irradiation with 1000 MJ / m 2 Only the results after irradiation are shown. Table 4 also shows the measurement results of the tensile strength and tensile modulus of elasticity of the dumbbell test piece of Comparative Example 6 before and after irradiation.

[0070] [Table 4]

[0071] From Fig. 3, it can be seen that the test piece of Example 14 formed from a composition containing (A) glycol lignin, (B) an olefin-based polymer, and (C) carbon fiber as a reinforcing filler maintained its mechanical strength even after the weather resistance test. On the other hand, as shown in Fig. 4, the dumbbell test piece of Comparative Example 1 not containing (A) glycol lignin showed a gradual decrease in tensile strength and tensile modulus with increasing irradiation energy. Also, as shown in Fig. 5 and Table 4, at 1000 MJ / m 2 The dumbbell test piece of Comparative Example 6 after irradiation had a slight increase in tensile strength compared to before irradiation, but the tensile modulus was clearly decreased. [Industrial Applicability]

[0072] According to the present invention, it is possible to obtain a polyolefin composition and a molded article thereof, which can reduce the environmental load and have excellent mechanical properties and weather resistance at the same time. Therefore, the polyolefin composition of the present invention can be widely used in the application fields of polyolefins, including automobile parts.

Claims

1. A polyolefin composition comprising (A) 10 to 60 mass% of glycol lignin and (B) 40 to 90 mass% of an olefin polymer, The polyolefin composition, wherein the olefin polymer (B) has a reactive site reactive with a hydroxyl group.

2. 2. The polyolefin composition according to claim 1, wherein the (A) glycol lignin is a modified lignin chemically modified with at least one glycol selected from the group consisting of ethylene glycol, propylene glycol, polyethylene glycol, polypropylene glycol, polyethylene polypropylene glycol, glycerin, and polyglycerin.

3. 3. The polyolefin composition according to claim 2, wherein the glycol is a polyethylene glycol having a weight average molecular weight of 100 to 2,000.

4. The polyolefin composition according to claim 1, wherein the olefin polymer (B) is a thermoplastic resin or a thermoplastic elastomer.

5. 2. The polyolefin composition according to claim 1, wherein the reactive site is at least one group selected from the group consisting of a carboxy group, a carboxy anhydride group, a glycidyl group, and an acrylate ester group, and / or a site modified with an unsaturated carboxylic acid or acid anhydride.

6. The polyolefin composition according to claim 1, wherein the olefin polymer (B) is a maleic anhydride-modified polyolefin resin.

7. The polyolefin composition of claim 1, further comprising (C) a reinforcing filler.

8. 8. The polyolefin composition according to claim 7, wherein the (C) reinforcing filler is at least one selected from the group consisting of glass fiber, glass flake, carbon fiber, graphite, carbon nanotube, graphene, molybdenum disulfide, wollastonite, mica, talc, pyrophyllite, smectite, imogolite, potassium titanate fiber, layered titanate, calcium silicate, aramid fiber, cellulose fiber, cellulose nanofiber, and zirconium phosphate.

9. A molded article of the polyolefin composition according to any one of claims 1 to 8.

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