Resin molding and resin composition

Abstract

To provide a resin molding which has high impact resistance and elongation, while maintaining high strength.SOLUTION: A resin molding contains polypropylene, a fine cellulose fiber and a β crystal nucleus agent. As for the resin molding, in wide-angle X-ray diffraction measurement, a diffraction peak derived from an α crystal (040) plane of polypropylene in which a scattering vector s is observed at 1.92±0.1 nm-1, and a diffraction peak area (Pβ) derived from a β crystal (300) plane of polypropylene in which the scattering vector s is observed at 1.83±0.1 nm-1 are observed. A ratio R of the diffraction peak area (Pβ) derived from a diffraction peak area (Pβ) derived from the β crystal (300) plane of the polypropylene to a diffraction peak area (Pα) derived from the α crystal (040) plane of the polypropylene is 100% or more.SELECTED DRAWING: None

Description

[Technical Field]

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

[0002] Cellulose fibers are lightweight and strong materials, and are therefore expected to be used as reinforcing materials for resin compositions.

[0003] For example, Patent Document 1 discloses a resin molded article containing polypropylene and fine cellulose fibers, in which, in wide-angle X-ray diffraction measurement, the ratio of the diffraction peak area (Pβ) derived from the β-crystal (300) plane to the diffraction peak area (Pα) derived from the α-crystal (040) plane is more than 0% and less than 50%. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] International Publication No. 2020 / 071434 Summary of the Invention [Problem to be solved by the invention]

[0005]

[0003] Resin molded articles used in particular for automobile parts are required to have not only high strength but also high impact resistance and elongation. In contrast, as described above, molded articles made of resin compositions containing polyolefins such as polypropylene and cellulose fibers have relatively high strength, but tend to have low impact resistance and elongation. Therefore, there is a demand for resin molded articles that have high impact resistance and elongation while maintaining strength as much as possible.

[0006] An object of the present invention is to provide a resin molded article and a resin composition that have high impact resistance and elongation while maintaining high strength. [Means for solving the problem]

[0007] [1] A resin molded product comprising a resin composition containing polypropylene, fine cellulose fibers, and a β-crystal nucleating agent, and in wide-angle X-ray diffraction measurement, the scattering vector s is 1.92±0.1 nm -1 The diffraction peak at 1.83±0.1nm is due to the (040) plane of the α-crystal of polypropylene. -1 and a diffraction peak area (Pβ) derived from the β-crystal (300) plane of polypropylene observed at the position (Pα), and the ratio R of the diffraction peak area (Pβ) derived from the β-crystal (300) plane to the diffraction peak area (Pα) derived from the α-crystal (040) plane is 100% or more. [2] The resin molded article according to [1], wherein the ratio R is 150% or more. [3] The resin molded article according to [1] or [2], wherein the β-crystal nucleating agent comprises a structure represented by the following general formula (1): [ka] (In general formula (1), M represents a monovalent to trivalent metal atom having a specific gravity of 4.0 or less, or a divalent or trivalent metal atom having a specific gravity of 4.0 or less and having a hydroxy group bonded thereto; a represents 1 or 2; b represents 1 or 3; x represents an integer of 1 to 3; Satisfies ax=2b. Z represents a group represented by the following general formula (2) or (3): [ka] (In the general formulas (2) and (3), * represents the position at which the group is linked to the carbonyl group in general formula (1), Y represents a direct bond or an alkylene group having 1 to 4 carbon atoms; R1~R 10 each independently represents a hydrogen atom, a hydroxy group, a halogen atom, an alkyl group having 1 to 10 carbon atoms, a halogenated alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, or an alkenyl group having 2 to 10 carbon atoms. [4] The resin molded article according to [3], wherein M is lithium, sodium, potassium, magnesium, calcium, barium, aluminum, hydroxyaluminum, or dihydroxyaluminum. [5] The resin molded product according to any one of [1] to [4], wherein the fine cellulose fibers include acylated fine cellulose fibers. [6] The resin molded article according to any one of [1] to [5], which is an injection molded article of the resin composition. [7] A resin composition used for preparing the resin molded article according to any one of [1] to [6], wherein when the resin composition is molded into the resin molded article, a scattering vector s of 1.92±0.1 nm in wide-angle X-ray diffraction measurement is -1 The diffraction peak at 1.83±0.1nm is due to the (040) plane of the α-crystal of polypropylene. -1 and a diffraction peak area (Pβ) derived from the β-crystal (300) plane of polypropylene observed at the position (Pα), and the ratio R of the diffraction peak area (Pβ) derived from the β-crystal (300) plane to the diffraction peak area (Pα) derived from the α-crystal (040) plane is 100% or more. [Effects of the Invention]

[0008] According to the present invention, it is possible to provide a resin molded article and a resin composition that have high impact resistance and elongation while maintaining high strength. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, a resin molded product according to one embodiment of the present invention and a resin composition used therein will be specifically described. In this specification, unless otherwise specified, the term "to" means a numerical range including the lower and upper limits, which are the endpoints.

[0010] 1. Resin molding A resin molded article according to one embodiment of the present invention is a resin molded article obtained by molding a resin composition containing polypropylene, fine cellulose fibers, and a β-crystal nucleating agent.

[0011] Polypropylene is known to have various crystalline structures, such as α-crystals and β-crystals. α-crystals are monoclinic, and β-crystals are hexagonal. The present inventors have discovered that, in the resin molded article, when the content ratio of β-crystals to α-crystals of polypropylene is higher than a certain level, it is possible to significantly improve impact resistance and elongation while minimizing the decrease in strength.

[0012] Specifically, it was newly discovered that when the ratio R of the peak area originating from β crystals to the diffraction peak area originating from α crystals in wide-angle X-ray diffraction is 100% or more, when a resin molded body is deformed by tension or impact, stress on the molded body does not concentrate in certain areas, but rather the deformation occurs uniformly. As a result, voids are less likely to form between the fine cellulose and the resin, and cracks themselves are less likely to occur in the resin. In other words, it was previously unknown that forming β crystals at a higher level than conventional methods makes voids and cracks less likely to occur in resin molded bodies. It was also revealed that the reduced void and crack formation makes the resin molded body less likely to break, resulting in improved impact resistance and tensile elongation. Although the reason why voids and cracks are less likely to occur in the resin molded body is unclear, it is presumed that the addition of a β-crystal nucleating agent, molding conditions, etc., causes changes in the degree of orientation and crystalline form of the polypropylene, improving the adhesion between the fine cellulose and polypropylene, or (when a rubber component is included) the adhesion between the polypropylene and the rubber component. As a result, the resin molded body deforms uniformly throughout without localized deformation, which is thought to improve impact resistance and tensile elongation.

[0013] That is, in wide-angle X-ray diffraction measurement, the resin molded body according to the present embodiment has a scattering vector s of 1.92±0.1 nm -1 Position and 1.83±0.1nm -1 Diffraction peaks are observed at the positions shown in the figure. The scattering vector s is 1.92±0.1 nm. -1 The diffraction peak at the position is a diffraction peak derived from the (040) plane of the α-crystal of polypropylene, and is 1.83±0.1 nm -1The diffraction peak at the position is a diffraction peak derived from the (300) plane of the β crystal of polypropylene. And the scattering vector s is 1.92±0.1nm -1 The area of the diffraction peak (Pα) derived from the α crystal (040) plane observed at the position of 1.83±0.1 nm -1 The ratio R of the area (Pβ) of the diffraction peak originating from the β crystal (300) plane observed at this position is 100% or more. The ratio R is expressed by the following formula. Ratio R (%) = [diffraction peak area (Pβ) derived from the β crystal (300) plane / diffraction peak area (Pα) derived from the α crystal (040) plane] × 100

[0014] As described above, when the ratio R of the resin molded article is 100% or more, voids are less likely to occur and cracks are less likely to occur when the resin molded article is subjected to tension or impact. This makes it possible to improve impact resistance and elongation while minimizing reduction in strength. From the same perspective, the ratio R is preferably 150% or more, and more preferably 200% or more. On the other hand, the upper limit of the ratio R is not particularly limited, but from the perspective of further suppressing reduction in strength, it can be set to 2000% or less. The method for measuring the ratio R will be described in detail later.

[0015] The ratio R can be adjusted mainly by the composition of the polypropylene, the type and content of the β-crystal nucleating agent, molding conditions (preferably injection molding conditions), etc. For example, when a β-crystal nucleating agent is added and the injection molding conditions are such that, taking into account the heat resistance temperature of fine cellulose, the molding temperature is set low, for example, to 180 to 200°C, and the cooling temperature is set high, for example, to 30 to 60°C, thereby maintaining high strength of the molded body while increasing impact resistance and tensile elongation.

[0016] The resin molded body according to this embodiment will be described below.

[0017] As described above, the resin molded article is obtained by molding a resin composition containing polypropylene, fine cellulose fibers, and a β-crystal nucleating agent.

[0018] 1-1.Polypropylene The polypropylene is not particularly limited, and may be a propylene homopolymer or a copolymer of propylene and a monomer copolymerizable therewith.

[0019] Examples of monomers copolymerizable with propylene include ethylene and α-olefins. Preferred examples of α-olefins include 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 1-octene, and 1-decene, with 1-butene, 1-hexene, and 1-octene being more preferred. In the case of a copolymer, the content of structural units derived from propylene may be 50 to 99.9 mass% of all structural units.

[0020] The copolymer may be a propylene random copolymer or a propylene block copolymer.

[0021] Examples of the propylene random copolymer include a propylene-ethylene random copolymer, a propylene-α-olefin random copolymer, and a propylene-ethylene-α-olefin random copolymer.

[0022] Examples of the propylene-α-olefin random copolymer include a propylene-1-butene random copolymer, a propylene-1-hexene random copolymer, a propylene-1-octene random copolymer, etc. Examples of the propylene-ethylene-α-olefin random copolymer include a propylene-ethylene-1-butene random copolymer, a propylene-ethylene-1-hexene random copolymer, a propylene-ethylene-1-octene random copolymer, etc.

[0023] The propylene block copolymer refers to a copolymer containing a propylene block and a copolymer block obtained by copolymerizing propylene with at least one monomer selected from ethylene and an α-olefin. The propylene block refers to a propylene homopolymer component or a copolymer component obtained by copolymerizing mainly propylene with ethylene or an α-olefin.

[0024] Examples of propylene block copolymers include (propylene)-(propylene-ethylene) copolymer, (propylene)-(propylene-ethylene-1-butene) copolymer, (propylene)-(propylene-ethylene-1-hexene) copolymer, (propylene)-(propylene-1-butene) copolymer, (propylene)-(propylene-1-hexene) copolymer, (propylene-ethylene)-(propylene-ethylene) copolymer, (propylene-ethylene)-(propylene-ethylene-1-butene) copolymer, (propylene-ethylene)-(propylene-ethylene-1-butene) copolymer, (propylene-ethylene)-(propylene-ethylene-1-hexene) copolymer. -hexene) copolymer, (propylene-ethylene)-(propylene-1-butene) copolymer, (propylene-ethylene)-(propylene-1-hexene) copolymer, (propylene-1-butene)-(propylene-ethylene) copolymer, (propylene-1-butene)-(propylene-ethylene-1-butene) copolymer, (propylene-1-butene)-(propylene-ethylene-1-hexene) copolymer, (propylene-1-butene)-(propylene-1-butene) copolymer, (propylene-1-butene)-(propylene-ethylene-1-hexene) copolymer, and the like are included.

[0025] The content of the component soluble in n-decane at 23°C in the copolymer is preferably 0.1 to 40% by mass, more preferably 1 to 30% by mass. When the content of the component soluble in n-decane is within the above range, the content of, for example, ethylene or α-olefin is high, which can further increase the elongation at break and impact resistance of the resin molded article.

[0026] The intrinsic viscosity [η] of the n-decane soluble portion of the copolymer at 23° C. is preferably, for example, 1.0 to 9.0 dl / g.

[0027] n-Decane solvent fractionation can be carried out, for example, by the following procedure. The copolymer is added to n-decane at 135°C and thoroughly stirred to completely dissolve the soluble components (soluble polymer). The temperature is then lowered to 23°C and the mixture is left standing for 24 hours. The resulting solution is then centrifuged, and the separated liquid phase is decanted into acetone to precipitate the polymer. The precipitate is then filtered, washed, and dried to obtain the components soluble in n-decane at 23°C.

[0028] Among these, from the viewpoints of strength and impact resistance, homopolypropylene, propylene-ethylene-1-octene copolymer, and propylene block copolymer are preferred. From the viewpoint of further improving impact resistance and elongation, propylene block copolymer is preferred, and from the viewpoint of further improving strength, homopolypropylene is preferred.

[0029] The MFR of polypropylene may be set according to the purpose, but from the viewpoint of moldability, it is preferably 0.5 to 1000 g / 10 min, more preferably 1.0 to 500 g / 10 min, and even more preferably 1.0 to 100 g / 10 min. The MFR can be measured in accordance with ASTM D1238 using a melt indexer at 230°C under a load of 2.16 kg.

[0030] The polypropylene may be used alone or in combination of two or more. For example, the polypropylene may further contain acid-modified polypropylene in addition to non-acid-modified polypropylene. The acid-modified polypropylene can improve the compatibility between the polypropylene and the fine cellulose fibers, and can further increase the strength of the resin molded body.

[0031] Acid-modified polypropylene includes the above-mentioned polypropylene modified with, for example, an unsaturated carboxylic acid or a derivative thereof. Examples of unsaturated carboxylic acids include maleic acid, fumaric acid, itaconic acid, acrylic acid, and methacrylic acid. Examples of unsaturated carboxylic acid derivatives include maleic anhydride and itaconic anhydride. Preferred examples of acid-modified polypropylene include maleic acid-modified polypropylene and maleic anhydride-modified polypropylene.

[0032] The content of polypropylene in the resin composition is preferably 20 to 99 parts by mass, more preferably 40 to 97 parts by mass, even more preferably 70 to 97 parts by mass, and may be 85 to 95 parts by mass, relative to 100 parts by mass of the total amount of polypropylene and fine cellulose fibers. When the content of polypropylene is 20 parts by mass or more, impact resistance and elongation are more likely to be improved. When the content of polypropylene is 99 parts by mass or less, the content ratio of fine cellulose fibers is above a certain level, and strength can be further improved.

[0033] When the polypropylene contains acid-modified polypropylene, the content of the acid-modified polypropylene is preferably 0.2 to 10.0 parts by mass, more preferably 0.5 to 5.0 parts by mass, per 100 parts by mass of the total amount of polypropylene. By setting the content of the acid-modified polypropylene within the above range, the strength of the resin molded article can be further increased.

[0034] The polypropylene may contain biomass-derived propylene. The propylene constituting the polymer may be only biomass-derived propylene, or may contain both biomass-derived propylene and fossil fuel-derived propylene. Biomass-derived propylene is propylene obtained from any renewable natural raw material or its residue, such as plant-derived or animal-derived, including fungi, yeast, algae, and bacteria, and contains propylene as carbon. 14 C isotope 10 -12The biomass-derived propylene may be obtained by a conventionally known method. It is preferable for polypropylene to contain biomass-derived propylene from the viewpoint of reducing environmental impact (mainly greenhouse gas emissions). If the polymer production conditions, such as the polymerization catalyst, polymerization process, and polymerization temperature, are the same, even if the raw material propylene contains biomass-derived propylene, 14 C isotope 10 -12 ~10 -14 Other than the proportion of propylene in the polymer, its molecular structure is the same as that of polypropylene, which is made from fossil fuel-derived propylene. Therefore, its performance is said to be the same.

[0035] The polypropylene may contain propylene derived from chemical recycling. The propylene constituting the polymer may be solely propylene derived from chemical recycling, or may contain propylene derived from chemical recycling and propylene derived from fossil fuels and / or propylene derived from biomass. The propylene derived from chemical recycling may be obtained by a conventionally known method. As mentioned above, it is preferable for polypropylene to contain chemically recycled propylene from the viewpoint of reducing the environmental load (mainly reducing waste). Even if the raw material monomer contains chemically recycled monomer, the chemically recycled monomer is a monomer obtained by depolymerizing or thermally decomposing polymers such as waste plastics to return them to monomer units such as propylene, or a monomer produced using such a monomer as a raw material. Therefore, if the polymer production conditions, such as the polymerization catalyst, polymerization process, and polymerization temperature, are the same, the molecular structure is equivalent to that of polypropylene made from monomers derived from fossil fuels. Therefore, the performance is also said to be the same.

[0036] The total amount of polypropylene and fine cellulose fibers in the resin composition is preferably 70 to 99.9% by mass, more preferably 80 to 99% by mass.

[0037] 1-2. Microcrystalline cellulose fiber The fine cellulose fibers are fibrous cellulose obtained from a cellulose raw material and contain at least fibers having a fiber diameter of 1000 nm or less. The fine cellulose fibers may further contain fibers having a fiber diameter of more than 1000 nm.

[0038] Cellulose raw materials refer to various forms of materials primarily composed of cellulose. Examples of cellulose raw materials that can be used include wood-based virgin pulps such as softwood bleached kraft pulp (NBKP), hardwood bleached kraft pulp (LBKP), and softwood unbleached kraft pulp (NUKP), as well as recycled paper pulp made from recycled paper. In addition to the above, wood pulp derived from softwoods or hardwoods and pulp derived from non-wood plants can also be used. Examples of non-wood plant-derived pulp include straw pulp, bagasse pulp, reed pulp, kenaf pulp, linen pulp, ramie pulp, hemp pulp, flax pulp, and bamboo pulp. Pulp may or may not contain lignin and / or lignocellulose. During the production process, pulp may be subjected to a lignin removal treatment, or lignocellulose fibers may be subjected to a lignin removal treatment. Also, plant-derived fibers that do not originally contain lignin can be used.Furthermore, for example, dissolving pulp, sulfite pulp, kraft pulp, semi-chemical pulp, chemi-ground pulp, refiner ground pulp, thermomechanical pulp, groundwood pulp, refiner ground pulp, thermomechanical pulp, and pulp for fiberboard may be used.

[0039] The number-average fiber diameter of the fine cellulose fibers is, for example, preferably 5 to 10,000 nm, more preferably 10 to 5,000 nm. The average fiber length of the fine cellulose fibers is, for example, preferably 0.1 to 5 mm, more preferably 0.5 to 1 mm. The number-average fiber diameter and average fiber length can be measured by image analysis using a scanning electron microscope (SEM).

[0040] In the resin molded product, at least a part of the fine cellulose fibers is opened and nanosized during the manufacturing process. The degree of opening of the fine cellulose fibers in the resin molded product can be confirmed by X-ray CT measurement.

[0041] The fine cellulose fibers may be fine cellulose fibers having acyl groups (also referred to as "acylated fine cellulose fibers") or fine cellulose fibers having no acyl groups. From the viewpoint of further improving compatibility with polypropylene and obtaining a resin molded product with higher strength, the fine cellulose fibers preferably include acylated fine cellulose fibers.

[0042] <Acylated microfine cellulose fiber> Acylated microfine cellulose fibers are microfine cellulose fibers into which an acyl group has been introduced (acylated).

[0043] (acylation) The acylated microfibrillated cellulose fibers are those in which at least a portion of the hydroxyl groups present in cellulose have been substituted with acyl groups. That is, the acylated microfibrillated cellulose fibers are preferably those in which the hydroxyl groups present in at least one of cellulose and hemicellulose (including lignocellulose) have been substituted with a residue obtained by removing a hydrogen atom from the carboxyl group of at least one carboxylic acid selected from the group consisting of saturated fatty acids, unsaturated carboxylic acids, monounsaturated fatty acids, diunsaturated fatty acids, triunsaturated fatty acids, tetraunsaturated fatty acids, pentaunsaturated fatty acids, hexaunsaturated fatty acids, aromatic carboxylic acids, dicarboxylic acids, amino acids, maleimide compounds, and phthalimide compounds.

[0044] Examples of saturated fatty acids include formic acid, acetic acid, propionic acid, butyric acid, valeric acid, pivalic acid, hexanoic acid (caproic acid), heptanoic acid (enanthic acid), octanoic acid (caprylic acid), pelargonic acid, decanoic acid (capric acid), undecylic acid, lauric acid, tridecylic acid, myristic acid, pentadecylic acid, palmitic acid, margaric acid, stearic acid, nonadecylic acid, and arachidic acid. Examples of aromatic-substituted saturated fatty acids include phenoxyacetic acid, 3-phenoxypropionic acid, 4-phenoxybutyric acid, and 5-phenoxyvaleric acid. Examples of unsaturated carboxylic acids include acrylic acid and methacrylic acid. Examples of monounsaturated fatty acids include crotonic acid, myristoleic acid, palmitoleic acid, oleic acid, and ricinoleic acid. Examples of diunsaturated fatty acids include sorbic acid, linoleic acid, and eicosadienoic acid. Examples of triunsaturated fatty acids include linolenic acid, pinolenic acid, and eleostearic acid. Examples of tetraunsaturated fatty acids include stearidonic acid and arachidonic acid. Examples of pentaunsaturated fatty acids include bosseopentaenoic acid and eicosapentaenoic acid. Examples of hexaunsaturated fatty acids include docosahexaenoic acid and nisinic acid. Examples of aromatic carboxylic acids include benzoic acid, phthalic acid, isophthalic acid, terephthalic acid, salicylic acid, gallic acid (3,4,5-trihydroxybenzenecarboxylic acid), and cinnamic acid (3-phenylprop-2-enoic acid). Examples of dicarboxylic acids include oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, fumaric acid, and maleic acid. Examples of amino acids include glycine, β-alanine, and ε-aminocaproic acid (6-aminohexanoic acid). Examples of the maleimide compound and the phthalimide compound include a maleimide compound represented by the following formula (a) and a phthalimide compound represented by the following formula (b).

[0045] [ka]

[0046] [ka]

[0047] Among these, the acylated microfibrillated cellulose fibers are preferably those in which at least a portion of the hydroxyl groups have been substituted with lower acyl groups. A lower acyl group refers to an acyl group having 1 to 5 carbon atoms. R in the acyl group (R-CO-) is preferably an alkyl group having 1 to 5 carbon atoms. Examples of the alkyl group having 1 to 5 carbon atoms include linear or branched alkyl groups such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tert-butyl (pivaloyl), and pentyl.

[0048] Of the above, the acylated fine cellulose fibers are preferably those in which the acyl group is an acetyl group (CH3-CO-) from the viewpoints of ease of production and production costs.

[0049] The degree of substitution of acyl groups (DS) (for example, the degree of acetyl group substitution in the case of acetylated microfibrillated cellulose fibers) is preferably 0.4 to 1.3, more preferably 0.6 to 1.1, from the viewpoint of further increasing the strength of the resin molded article. The degree of substitution of acyl groups can be measured by the method described in the Examples below.

[0050] The acylation reaction can be carried out in a short time by suspending the cellulose raw material in an anhydrous aprotic polar solvent capable of swelling the raw material, such as N-methylpyrrolidone (NMP) or N,N-dimethylformamide (DMF), and using the carboxylic acid anhydride or acid chloride in the presence of a base. However, the reaction can also be carried out without a base or an aprotic polar solvent by carrying out the reaction with stirring. The base used in this acylation reaction is preferably pyridine, N,N-dimethylaniline, sodium carbonate, sodium bicarbonate, potassium carbonate, etc., with potassium carbonate being more preferred. The acylation reaction is preferably carried out with stirring, for example, at room temperature to 100°C.

[0051] (Washing) The acylated microfibrillated cellulose fibers obtained by acylation are preferably subjected to a washing treatment using water or the like after the modification treatment.

[0052] (dehydration) In the washing treatment, dehydration may be carried out as necessary. Dehydration may be carried out, for example, by centrifugal separation. Dehydration is preferably carried out until the solid content in the solvent is about 25 to 50%.

[0053] (Dry) The acylated cellulose fiber may be used in a dried or wet state in the kneading step for producing the masterbatch. When used in a dried state, the drying can be carried out using, for example, a blower dryer or a vacuum dryer. The drying can be carried out, for example, until the moisture content of the acylated cellulose fiber reaches about 1 to 5%.

[0054] The content of the fine cellulose fibers in the resin composition is preferably 1 to 80 parts by mass, more preferably 3 to 60 parts by mass, even more preferably 3 to 30 parts by mass, and may be 5 to 15 parts by mass, relative to 100 parts by mass of the total of polypropylene and fine cellulose fibers. When the content of the fine cellulose fibers is 1 part by mass or more, the strength of the resin molded body can be further increased. When the content of the fine cellulose fibers is 80 parts by mass or less, the impact resistance and elongation of the resin molded body can be more unlikely to be impaired.

[0055] 1-3. β-crystal nucleating agent The β-crystal nucleating agent is not particularly limited as long as it is a crystallization nucleating agent that selectively forms β-crystals of polypropylene when added to a resin composition containing polypropylene and molded. Examples of such β-crystal nucleating agents include alkali or alkaline earth metal salts of carboxylic acids, aromatic sulfonic acid compounds, di- or tri-esters of di- or tribasic carboxylic acids, tetraoxaspiro compounds, imide carboxylic acid derivatives, two-component compounds consisting of component A, which is an organic dibasic acid, and component B, which is an oxide, hydroxide, or salt of a metal in Group IIA of the periodic table, iron oxides having nanoscale sizes, pigment compounds (e.g., quinacridone), and amide compounds, with amide compounds being preferred. The β-crystal nucleating agents can be used alone or in combination of two or more.

[0056] The amide compound is preferably an amide compound containing an alicyclic or aromatic ring. Examples of such amide compounds include compounds represented by the following general formula (1):

[0057] [ka]

[0058] In general formula (1), M represents a monovalent to trivalent metal atom having a specific gravity of 4.0 or less, or a divalent to trivalent metal atom having a specific gravity of 4.0 or less and having a hydroxy group bonded thereto. Examples of M include metal atoms such as lithium, sodium, potassium, magnesium, calcium, barium, and aluminum. The divalent or trivalent metal atom may be bonded to a hydroxy group. Examples of divalent or trivalent metal atoms bonded to a hydroxy group include hydroxyaluminum and dihydroxyaluminum. From the viewpoint of obtaining a nucleating agent having a superior β-crystal forming effect, M is preferably lithium, sodium, potassium, magnesium, calcium, barium, aluminum, hydroxyaluminum, or dihydroxyaluminum, more preferably lithium, sodium, potassium, calcium, or hydroxyaluminum, and particularly preferably sodium.

[0059] In the general formula (1), a represents 1 or 2.

[0060] In the general formula (1), b represents 1 or 3, and is preferably 1.

[0061] In general formula (1), x represents an integer of 1 to 3, and is preferably 1 or 2. ax=2b is satisfied.

[0062] In general formula (1), Z represents a group represented by the following general formula (2) or (3): In particular, from the viewpoint of facilitating the formation of β crystals, Z is preferably a group represented by general formula (3).

[0063] [ka]

[0064] In general formulas (2) and (3), * indicates the position at which the carbonyl group in general formula (1) is linked.

[0065] In general formulas (2) and (3), Y represents a direct bond or an alkylene group having 1 to 4 carbon atoms. Examples of the alkylene group having 1 to 4 carbon atoms include a methylene group, an ethylene group, a propylene group, a butylene group, and an isobutylene group. From the viewpoint of excellent β-crystal forming activity, Y is preferably a direct bond or a methylene group.

[0066] In general formulas (2) and (3), R to R 10 each independently represents a hydrogen atom, a hydroxy group, a halogen atom, an alkyl group having 1 to 10 carbon atoms, a halogenated alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, or an alkenyl group having 2 to 10 carbon atoms.

[0067] Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, of which a chlorine atom is particularly preferred. Examples of the alkyl group having 1 to 10 carbon atoms include a linear or branched alkyl group, and a cycloalkyl group having 3 to 10 carbon atoms. Specific examples include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, a cyclopropyl group, an n-butyl group, a sec-butyl group, a tert-butyl group, an isobutyl group, a cyclobutyl group, an n-amyl group, a tert-amyl group, a cyclopentyl group, an n-hexyl group, a cyclohexyl group, an n-heptyl group, a cycloheptyl group, an n-octyl group, an isooctyl group, a tert-octyl group, a 2-ethylhexyl group, an n-nonyl group, an isononyl group, and an n-decyl group. Examples of halogenated alkyl groups having 1 to 10 carbon atoms include those in which some or all of the hydrogen atoms of the above alkyl groups have been substituted with the above halogen atoms. Examples of the alkoxy group having 1 to 10 carbon atoms include a linear or branched alkoxy group, or a cycloalkoxy group having 5 to 10 carbon atoms. Specific examples include a methoxy group, an ethoxy group, an n-propoxy group, an n-butoxy group, an n-hexyloxy group, a 1-methylethoxy group, a 2-methylpropoxy group, a 1-methylbutoxy group, a 4-methylpentyloxy group, and a cyclohexyloxy group. Examples of alkenyl groups having 2 to 10 carbon atoms include vinyl, propenyl, butenyl, hexenyl, octenyl, decenyl, etc. The position of the double bond may be the α-position, internal position, or ω-position. Among these, R1~R 10 are each preferably a hydrogen atom or a halogen atom, and particularly preferably a hydrogen atom.

[0068] Specific examples of the compound represented by general formula (1) are listed below, but the invention is not limited to these.

[0069] [ka]

[0070] The compound represented by general formula (1) can be produced, for example, by a method in which a metal salt of aspartic acid is reacted with a carboxylic acid chloride such as benzoic acid chloride or cyclohexanecarboxylic acid chloride in the presence of a base.

[0071] Further, other examples of the amide compound include compounds represented by the following general formula (4). [ka]

[0072] In general formula (4), R 11 represents an aromatic ring, an alicyclic ring, or an aliphatic hydrocarbon having 2 to 24 carbon atoms. 11 is preferably an aromatic ring. Examples of aromatic rings include a benzene ring, a naphthalene ring, and an anthracene ring. It is preferably an alicyclic ring.

[0073] In general formula (4), R 12 and R 13 Each represents an alicyclic ring or an aromatic ring. 12 and R 13 is preferably an alicyclic ring. Examples of the alicyclic ring include cyclohexane, cycloheptane, and cyclooctane.

[0074] Examples of the amide compound represented by general formula (4) include N,N'-diphenylhexanediamide, N,N'-dicyclohexylterephthalamide, N,N'-dicyclohexyl-2,6-naphthalenedicarboxamide, etc. Among these, N,N'-dicyclohexyl-2,6-naphthalenedicarboxamide is preferred.

[0075] The content of the β-crystal nucleating agent in the resin composition is preferably 0.001 to 2 parts by mass per 100 parts by mass of the total of polypropylene and fine cellulose fibers. When the content of the β-crystal nucleating agent is 0.001 part by mass or more, a larger amount of β-crystals of polypropylene can be formed, thereby further improving the impact resistance and elongation of the resin molded body. When the content of the β-crystal nucleating agent is 2 parts by mass or less, concerns about bleeding from the resin molded body are further reduced, and strength is further less likely to be impaired. From the same viewpoint, the content of the β-crystal nucleating agent is preferably 0.005 part by mass or more and 1.0 part by mass or less, more preferably 0.05 part by mass or more and 0.5 part by mass or less, and may be more than 0.1 part by mass and 0.5 part by mass or less.

[0076] 1-4.Other ingredients The resin composition may further contain other components in addition to the polypropylene, fine cellulose fiber, and β-crystal nucleating agent described above, provided that the effects of the present invention are not impaired. Such other components include stabilizers, antioxidants, UV absorbers, colorants (dyes, organic pigments, inorganic pigments), fillers, lubricants, plasticizers, processing aids such as acrylic processing aids, foaming agents, lubricants such as paraffin wax, surface treatment agents, crystallization nucleating agents, release agents, hydrolysis inhibitors, antiblocking agents, antistatic agents, antifogging agents, antifogging agents, ion trapping agents, flame retardants, flame retardant aids, swelling agents, rubber components, etc.

[0077] Among these, the resin composition preferably contains fine particles or a stabilizer having an ultraviolet blocking function when the resin composition is used outdoors and exposed to sunlight, ultraviolet rays, and temperature changes. In particular, when the resin composition contains acylated microfibrillated cellulose fibers, the hydrolysis of the acyl groups of the acylated microfibrillated cellulose fibers, which is accelerated by long-term exposure to light, can be further suppressed, and deterioration of the surface properties of the resin molded product (whitening, which appears white due to light scattering) caused by acylation-derived acids generated by hydrolysis can be further suppressed.

[0078] (Fine particles with ultraviolet blocking properties) The fine particles having ultraviolet blocking ability (ultraviolet blocking fine particles) can further suppress the deterioration of the resin molded article due to light, thereby further suppressing the whitening phenomenon in which the surface appears white due to light scattering caused by deterioration of the surface properties.

[0079] The ultraviolet-blocking particles are not particularly limited as long as they are particles that absorb or reflect ultraviolet rays. Examples of ultraviolet-blocking particles include carbon black, titanium oxide, and calcium carbonate. From the viewpoint of ultraviolet-blocking ability, carbon black is more preferred. Furthermore, from the viewpoint of ultraviolet-blocking ability, the average particle size of the ultraviolet-blocking particles is preferably 3 to 500 nm, more preferably 10 to 100 nm.

[0080] When the resin composition contains ultraviolet-blocking particles, the content of the ultraviolet-blocking particles in the resin composition is preferably 0.5 parts by mass or more, more preferably 0.5 to 10.0 parts by mass, and even more preferably 0.7 to 3.0 parts by mass, per 10 parts by mass of fine cellulose fibers (in the case of acylated fine cellulose fibers, fine cellulose fibers with acyl groups removed), from the viewpoint of further enhancing the ultraviolet-blocking ability. The content of the ultraviolet-blocking particles is preferably greater than the content of the stabilizer and antioxidant described below.

[0081] (stabilizer) The stabilizer reacts with or captures polymer radicals. Examples of the stabilizer include hindered amine light stabilizers (HALS), phenolic antioxidants (including hindered phenolic antioxidants), etc. Among these, from the viewpoints of compatibility with polypropylene and retention, it is preferable that the stabilizer contains at least one of a hindered amine light stabilizer (HALS) and a hindered phenolic antioxidant.

[0082] The content of the stabilizer in the resin composition is not particularly limited, but from the viewpoint of further suppressing a decrease in strength due to excessive addition and further suppressing whitening, it is preferably 0.001 to 10 parts by mass, and more preferably 0.01 to 5 parts by mass, per 10 parts by mass of fine cellulose fiber (in the case of acylated fine cellulose fiber, fine cellulose fiber with the acyl groups removed).

[0083] (antioxidant) The resin composition preferably contains an antioxidant. The antioxidant can further suppress deterioration of polypropylene and acylated microfibrillated cellulose fibers during heat kneading. Examples of such antioxidants include antioxidants other than phenolic antioxidants, such as phosphorus-based antioxidants and sulfur-based antioxidants. One type of antioxidant may be used alone, or two or more types may be used.

[0084] The content of the antioxidant in the resin composition is not particularly limited, but from the viewpoint of further suppressing a decrease in strength due to excessive addition, it is preferably 0.001 to 1 part by mass, more preferably 0.01 to 1 part by mass, per 10 parts by mass of fine cellulose fiber (in the case of acylated fine cellulose fiber, fine cellulose fiber with the acyl groups removed).

[0085] (swelling agent) When the resin composition contains an acid-modified polypropylene, the resin composition may contain a swelling agent that imparts a primary amine such as urea, biuret, or triuret, from the viewpoint of further increasing compatibility with the acid-modified polypropylene and further increasing the strength of the molded body.

[0086] The content of the swelling agent in the resin composition is not particularly limited, and from the viewpoint of further increasing the strength of the molded body, it is preferably 10 to 100 parts by mass, more preferably 15 to 80 parts by mass, and even more preferably 20 to 70 parts by mass per 100 parts by mass of fine cellulose fiber (in the case of acylated fine cellulose fiber, fine cellulose fiber with the acyl groups removed).

[0087] (rubber component) The resin composition may further contain a rubber component to improve impact resistance. Examples of the rubber component include natural rubber and synthetic rubbers such as butadiene rubber, isoprene rubber, chloroprene rubber, styrene-butadiene rubber, styrene-isoprene rubber, acrylic rubber, butyl rubber, and ethylene-propylene rubber. Among these, ethylene-propylene rubber, hydrogenated styrene-butadiene rubber, and hydrogenated styrene-isoprene rubber are preferred.

[0088] When the resin composition contains a rubber component, the content of the rubber component is preferably 1 to 30.0 parts by mass per 100 parts by mass of the total amount of polypropylene. By setting the rubber content within the above range, the impact resistance of the resin molded article can be further improved.

[0089] (others) In addition, when using a fatty acid metal salt (calcium stearate, zinc stearate, etc.) used as a lubricant among the above other components, from the viewpoint of further increasing the production rate of β crystals, it is more preferable to slightly delay the timing of mixing it with the β crystal nucleating agent rather than kneading it simultaneously.

[0090] 1-5.Physical properties As described above, the resin molded body has a scattering vector s of 1.92±0.1 nm in wide-angle X-ray diffraction measurement. -1 The diffraction peak at 1.83±0.1nm is due to the (040) plane of the α-crystal of polypropylene. -1 and a diffraction peak originating from the (300) plane of the β-crystal of polypropylene located at the position (Pα). The ratio R of the area of the diffraction peak originating from the (300) plane of the β-crystal (Pβ) to the area of the diffraction peak originating from the (040) plane of the α-crystal (Pα) is set within the above-mentioned range.

[0091] (Wide-angle X-ray diffraction measurements) A two-dimensional detector is preferred for wide-angle X-ray diffraction measurements. In the case of typical resin molded bodies, an intensity distribution in the azimuthal direction due to resin orientation can occur. A one-dimensional scintillation counter may not be able to accurately capture the intensity distribution due to orientation, so a two-dimensional detector is preferred.

[0092] The X-ray source preferably uses CuKα rays and has a pinhole shape. The X-ray beam diameter is preferably 5 μm to 1500 μm, and more preferably 7 μm to 1000 μm. By setting the beam diameter to 1500 μm or less, the position resolution can be further improved, making it easier to perform detailed analysis. By setting the beam diameter to 5 μm or more, the irradiation intensity can be further increased, and the measurement time can be shortened. Specifically, this can be performed by the method described in the Examples.

[0093] (Determination of ratio R) The two-dimensional diffraction image obtained by wide-angle X-ray diffraction measurement is integrated and averaged in the circumferential direction to convert it into a one-dimensional image. The upper limit of the integration range for integrating and averaging the measurement data to convert it into a one-dimensional image is preferably 90° or more, more preferably greater than 180°, and even more preferably 360°. The one-dimensional data is then used to determine the ratio of β crystals to α crystals.

[0094] Specifically, the obtained one-dimensional data is subjected to peak separation using a Gaussian function. When measuring using CuKα radiation, the peak separation is performed when the scattering vector s is 1.35 to 2.80 nm. -1 It is preferable to carry out the measurement in the range of 2θ=12° to 25°. -1 This is not only more suitable for the region where diffraction peaks due to polypropylene crystals are observed, but also reduces the mixing of information due to small-angle scattering and information due to air scattering. -1 If the angle is equal to or less than this (lower than 25°), more diffraction peaks due to crystals are unlikely to be observed than necessary, making it easier to separate the peaks.

[0095] Scattering vector s is 1.35 to 2.80 nm -1 After separating the diffraction peaks into those derived from α crystals and those derived from β crystals within this range, the ratio of the diffraction peak area derived from the (300) plane of β crystals to the diffraction peak area derived from the (040) plane of α crystals is calculated, and this is taken as the ratio of β crystals to α crystals. Specifically, this can be done by the method described in the Examples.

[0096] Depending on the state of the observed peak, the peak separation may be arbitrary. For example, if the scattering vector s is 1.92±0.1 nm, -1 Position and 1.83±0.1nm -1 The overlapping part (1.82 nm) -1 ~1.93nm -1 ) and in this overlapping area, diffraction peaks originating from the (040) plane of the α crystal and / or the (300) plane of the β crystal may be observed. In such cases, the larger of the two diffraction peaks with the scattering vector s is 1.92±0.1 nm. -1 The diffraction peak at the position of the (040) plane of the α crystal is the peak originating from the (040) plane of the α crystal, and the scattering vector s is the smaller value of 1.83±0.1 nm. -1 The diffraction peak at the position is considered to be the diffraction peak derived from the (300) plane of the β crystal. If the diffraction peaks overlap in the overlapping area and cannot be separated into two, one of them is considered not to be included. This makes it possible to identify the assignment of the peaks in the overlapping area.

[0097] Additionally, because the diffraction angle of X-rays varies depending on the wavelength of the X-rays used, the diffraction angle is expressed using the scattering vector s, which is normalized by wavelength. The scattering vector s can be expressed as s = 2 sinθ / λ, using the X-ray diffraction angle 2θ and the X-ray wavelength λ. θ means 1 / 2 of the diffraction angle 2θ.

[0098] The shape of the resin molded body is not particularly limited, and may be any of a sheet, plate, film, three-dimensional structure, and the like.

[0099] The resin molded article can be used for various purposes, among which the resin molded article has an excellent balance between strength and impact resistance and is therefore preferably used for, for example, automobile parts (exterior parts, interior parts) and housings for various devices.

[0100] Examples of automotive exterior parts include bumpers, radiator grilles, front grilles, front panels, fenders, pillars, pillar covers, door mirror stay covers, glass run channels, door mirror housings, lamp housings, wheel covers, spoilers, air spoilers, weather strips, window moldings, belt moldings, sunroofs, front end modules, door modules, back door modules, outer panels, vehicle fuel delivery pipes, vehicle air intake pipes, etc. Examples of automotive interior parts include instrument panels, door trim panels, pillar trims, door trims, pillar garnishes, package trays, rear trays, console boxes, air conditioning ducts, etc.

[0101] 2. Manufacturing method of resin molded body The resin molded body can be produced by melt-kneading the polypropylene, fine cellulose fibers, and β-crystal nucleating agent, followed by molding the mixture into a predetermined shape. In this embodiment, the resin molded body can be produced by, for example, preparing a resin composition containing the polypropylene, fine cellulose fibers, and β-crystal nucleating agent, and molding the resin composition.

[0102] 2-1. Step of preparing a resin composition The resin composition can be obtained by heating and kneading the above-mentioned polypropylene, fine cellulose fibers, β-crystal nucleating agent, and any other components.

[0103] In this embodiment, it is preferable to open the fine cellulose fibers during this heating and kneading. As the opening of the fine cellulose fibers progresses, the fluidity of the resin composition changes, making it difficult to knead a resin composition with a high cellulose concentration. Furthermore, at low cellulose concentrations, the strength development effect is small. From these perspectives, it is preferable that the blending ratio of polypropylene and fine cellulose fibers is set so that the mass ratio of polypropylene to fine cellulose fibers in the resin composition falls within the above-mentioned range.

[0104] As the kneader, a single-screw or multi-screw kneader can be used. From the viewpoint of more reliably promoting defibration, a multi-screw kneader is preferred, and a twin-screw kneader is more preferred.

[0105] The heating temperature during kneading is preferably (Tm+10) to 200° C., where Tm (° C.) is the melting point of polypropylene. By keeping the heating temperature within this range, the polypropylene, cellulose fiber, β-crystal nucleating agent, and any other components can be mixed more uniformly.

[0106] The heating and kneading time varies depending on factors such as the production volume, but from the viewpoint of further suppressing deterioration of the resin due to heat and oxidation during heating and kneading, a shorter heating time is preferable. On the other hand, from the viewpoint of further promoting defibration and dispersion of the fine cellulose fibers, a relatively longer heating time is preferable. From these viewpoints, the heating and kneading time can be set to 5 seconds to 20 minutes. Furthermore, in heating and kneading, it is preferable to include a mechanism for strengthening kneading, such as a rotor or kneader, in the screw piece, and in particular, using rotors in multiple locations is even more preferable because it can promote nano-defibration.

[0107] Polypropylene, cellulose fibers, a β-crystal nucleating agent, and any other components may be kneaded simultaneously or sequentially. In the case of sequential kneading, for example, fine cellulose fibers and any other components may be kneaded to obtain a kneaded product (masterbatch), which may then be kneaded with polypropylene and a β-crystal nucleating agent.

[0108] When melt-kneading is performed using a melt-kneader, the polypropylene, cellulose fiber, β-crystal nucleating agent, and any other components may be fed to the kneader all at once and kneaded together, or may be fed to the kneader in multiple batches and kneaded together. When feeding in multiple batches, a side feeder or the like may be used.

[0109] The fine cellulose fibers to be used may be those obtained by dry pulverization, those obtained by wet pulverization after being in a water-containing state before pulverization, or those obtained by hydrating the cellulose fibers after dry pulverization.

[0110] Furthermore, the above components may be mixed in advance prior to heat kneading. For example, polypropylene and cellulose fibers may be mixed in advance prior to heat kneading. Specifically, dry cellulose fibers and polypropylene may be mixed and the resulting mixture may be supplied to the kneader; or dried cellulose fibers and powdered or granular polypropylene may be dispersed in a dispersion medium, mixed, and then dried and supplied to the kneader. Furthermore, when cellulose fibers and powdered or granular polypropylene are mixed in advance, other components may be further added and mixed.

[0111] As the mixing means, a bench roll, a Banbury mixer, a kneader, a planetary mixer, a Loedige mixer, a Henschel type mixer, a stirrer with stirring blades, or a revolution or rotation type stirrer can be used.

[0112] 2-2. Molding process The resin composition is then molded, thereby forming α crystals and β crystals. The degree of formation of α crystals and β crystals can also be adjusted by adjusting the molding conditions.

[0113] Molding methods include injection molding, mold molding, extrusion molding, blow molding, vacuum / compressed air molding, molding with a 3D printer, etc. Among these, injection molding is preferred.

[0114] The resin temperature (injection molding temperature) during injection molding is preferably (Tm+20) to 230°C, and more preferably (Tm+30) to 200°C, where Tm is the melting point of polypropylene (°C). The mold temperature (cooling temperature) during injection molding is preferably, for example, 30 to 60°C. The injection speed and dwell time can be adjusted as appropriate, taking into consideration the appearance of the molded product and the molding cycle.

[0115] 2-3. Other processes The method for producing the resin molded article may further include other steps as necessary.

[0116] Furthermore, when acylated cellulose fibers are used as the cellulose fibers, the α- and β-crystals of polypropylene tend to have strong interfacial interactions with the acylated cellulose fibers, and therefore, the formation of α- and β-crystals can be facilitated by adjusting the cellulose fiber content, slowing the cooling rate, or increasing the crystallization temperature to cause isothermal crystallization.

[0117] 3.Resin composition The resin composition according to the present embodiment is a resin composition used for producing the resin molded article. When the resin composition is molded, preferably injection molded, into a resin molded article, a scattering vector s of 1.92±0.1 nm is obtained by wide-angle X-ray diffraction measurement. -1 The diffraction peak at 1.83±0.1nm is due to the (040) plane of the α-crystal of polypropylene. -1 The diffraction peak area (Pβ) derived from the β-crystal (300) plane of polypropylene is observed at the position, and the ratio R of the diffraction peak area (Pβ) derived from the β-crystal (300) plane to the diffraction peak area (Pα) derived from the α-crystal (040) plane is 100% or more.

[0118] The molding conditions can be the same as those in the above-mentioned method for producing a resin molded article. In particular, the ratio R is preferably a value measured when the resin composition is injection molded under the following conditions: Injection molding temperature: 190℃ Mold temperature: 40℃ Injection time - pressure retention time: 20 seconds (primary filling time: 1 second) Cooling time: 5 seconds

[0119] That is, the components, contents, and physical properties contained in the resin composition according to this embodiment are the same as the components, contents, and physical properties contained in the resin composition for obtaining the resin molded body described above.

[0120] The shape of the resin composition is not particularly limited, and may be, for example, pellets, flakes, or powder. [Example]

[0121] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples.

[0122] 1.Material 1-1. Polypropylene (A) <Preparation of Polypropylene A-1> (1) Preparation of solid titanium catalyst component (a-1) After thoroughly replacing the air in a 2 L high-speed stirrer (manufactured by Tokushu Kika Kogyo), 700 ml of refined kerosene, 10 g of commercially available magnesium chloride, 24.2 g of ethanol, and 3 g of Emazol 320 (sorbita distearate, manufactured by Kao Atlas Corporation) were added. The system was heated with stirring and stirred at 120°C for 30 minutes at 800 rpm. With high-speed stirring, the mixture was transferred to a 2 L glass flask (equipped with a stirrer) containing 1 L of refined kerosene pre-cooled to -10°C using a 5 mm inner diameter Teflon (registered trademark) tube. The purified solid was thoroughly washed with purified n-hexane by filtration, yielding a solid adduct in which 2.8 moles of ethanol were coordinated per mole of magnesium chloride. The above solid adduct was suspended in 30 ml of decane, and 46.2 mmol in terms of magnesium atoms was introduced into 200 ml of titanium tetrachloride kept at -20°C while stirring. The mixture was heated to 80°C over 5 hours, and when it reached 80°C, 1.9 g of diisobutyl phthalate (DIBP) was added, and the mixture was heated to 120°C over 40 minutes. The temperature was maintained at 120°C for 90 minutes with stirring. After the 90-minute reaction, the solid portion was collected by hot filtration, resuspended in 200 ml of titanium tetrachloride, and then heated to 130°C, where it was maintained for 45 minutes with stirring. After the reaction was completed, the solid portion was collected by hot filtration again and thoroughly washed with decane and hexane at 100°C until no free titanium compounds were detected in the washings. The solid titanium catalyst component prepared by the above procedure was dried and stored. The solid titanium catalyst component (a-1) thus obtained had a composition of 2.4% by weight of titanium, 20% by weight of magnesium, 7.4% by weight of DIBP, and 0.5% by weight of ethanol residue. The catalyst particle size was 40 μm.

[0123] (2) Production of prepolymerization catalyst (b-1) 100.0 g of solid titanium catalyst component (a-1), 41.0 mL of triethylaluminum, and 10 L of heptane were placed in a 20 L autoclave equipped with a stirrer. The internal temperature was maintained at 15-20°C, and 600 g of propylene was added. The reaction was carried out with stirring for 100 minutes. After polymerization was completed, the solid component was allowed to settle, the supernatant liquid was removed, and the mixture was washed twice with heptane. The resulting prepolymerized catalyst was resuspended in purified heptane and adjusted with heptane to a solid catalyst component concentration of 0.7 g / L.

[0124] (3) Preparation of Polypropylene A-1 Propylene was continuously fed at 20 kg / h, hydrogen at 0.5 NL / h, prepolymerization catalyst (b-1) as a solid catalyst component at 0.48 g / h, triethylaluminum at 2.32 mL / h, and dicyclopentyldimethoxysilane at 1.46 mL / h into an 8 L tubular polymerization reactor, and polymerization was carried out in a liquid-filled state with no gas phase present. The temperature of the tubular polymerization reactor was 16°C, and the pressure was 3.4 MPa / G. The obtained slurry was sent to a tubular polymerization reactor with an internal volume of 58 L, where further polymerization was carried out. Propylene was continuously fed to the polymerization reactor at 23 kg / h and hydrogen at 55.0 NL / h, and polymerization was carried out in a liquid-filled state with no gas phase present. The temperature of the tubular polymerization reactor was 70°C, and the pressure was 3.4 MPa / G. The resulting slurry was transferred to a 70 L vessel polymerization reactor equipped with a stirrer, where further polymerization was carried out. Propylene was fed to the polymerization reactor at 45 kg / h, and hydrogen was fed to a hydrogen concentration of 2.9 mol% in the gas phase. Polymerization was carried out at a polymerization temperature of 70°C and a pressure of 3.0 MPa / G. The resulting slurry was transferred to a 2.4 L transfer tube, where it was contacted with 0.6 g / h of antistatic agent L-71 (ADEKA). The slurry was then gasified, gas-solid separation was performed, and the resulting polypropylene homopolymer powder was sent to a 480 L gas-phase polymerization reactor, where ethylene / propylene block copolymerization was carried out. Propylene, ethylene, and hydrogen were continuously supplied to the gas-phase polymerization reactor so that the gas composition within the reactor was ethylene / (ethylene + propylene) = 0.450 (molar ratio) and hydrogen / ethylene = 0.041 (molar ratio). Polymerization was carried out at a polymerization temperature of 70 °C and a pressure of 1.2 MPa / G. The resulting powder containing unreacted gas was subjected to gas-solid separation and vacuum drying at 80°C, thereby obtaining a propylene-ethylene block copolymer (A-1) having a polypropylene portion and an ethylene-propylene copolymer portion.

[0125] The properties of the resulting block copolymer (A-1) were as follows: MFR (2.16 kg load, 230°C) = 3.1 g / 10 min n-Decane solubles ratio = 19.0 wt% Ethylene content of n-decane soluble matter = 34.0 mass% Intrinsic viscosity of n-decane solubles [η] = 3.8 dl / g The MFR is a value measured in accordance with ASTM D1238, and the decane soluble content is a value measured by the method described above.

[0126] <Preparation of Polypropylene A-2> To an 8 L tubular polymerization reactor, 20 kg / h of propylene, 0.5 NL / h of hydrogen, 0.60 g / h of prepolymerization catalyst (b-1) as a solid catalyst component, 2.87 mL / h of triethylaluminum, and 1.75 mL / h of an equimolar mixture of dicyclopentyldimethoxysilane and N-butylmethyldimethoxysilane were continuously fed, and polymerization was carried out in a liquid-filled state with no gas phase present. The temperature of the tubular polymerization reactor was 16°C, and the pressure was 3.3 MPa / G. The obtained slurry was sent to a tubular polymerization reactor with an internal volume of 58 L, where further polymerization was carried out. Propylene was continuously fed to the polymerization reactor at 23 kg / h and hydrogen at 21.0 NL / h, and polymerization was carried out in a liquid-filled state with no gas phase present. The temperature of the tubular polymerization reactor was 70°C, and the pressure was 3.3 MPa / G. The obtained slurry was transferred to a 70 L vessel polymerization reactor equipped with a stirrer, where further polymerization was carried out. Propylene was fed to the polymerization reactor at 45 kg / h, and hydrogen was fed to a hydrogen concentration of 1.1 mol% in the gas phase. Polymerization was carried out at a polymerization temperature of 70°C and a pressure of 2.9 MPa / G. The obtained slurry was transferred to a transfer tube with an internal volume of 2.4 L, and the slurry was gasified, subjected to gas-solid separation, and vacuum dried at 80° C. This gave a homopolypropylene polymer (A-2). The MFR (2.16 kg load, 230° C.) of the obtained homopolypropylene polymer (A-2) was 3.0 g / 10 min.

[0127] <Acid-modified polypropylene A-3> Toyo Tack H1000P (Toyobo Co., Ltd., maleic anhydride-modified polypropylene)

[0128] 1-2. Microcrystalline cellulose fiber (B) <Preparation of acetylated fine cellulose fibers> 8.0 kg of water-containing unbleached softwood kraft pulp (NUKP) (solid content: 4.0 kg) was placed in a mixer ("FM150L" manufactured by Nippon Coke & Engineering Co., Ltd.), and stirring was started. The mixture was then dehydrated under reduced pressure at 50°C. 4.0 kg of acetic anhydride was then added, and the mixture was reacted at 80°C for 2 hours. After the reaction, the mixture was washed with water to obtain acetylated fine cellulose fibers (Ac-NUKP) as fine cellulose fibers having acyl groups. The acetylated fine cellulose fibers were then placed in a dryer and dried under reduced pressure at 60 to 70°C. The moisture content of the resulting acetylated fine cellulose fibers was measured using an infrared moisture meter. The moisture content was 2.3% by mass. The degree of acetyl substitution (DS) of the acetylated fine cellulose fibers was 0.7.

[0129] The degree of acetyl substitution (DS) was measured by the following method.

[0130] (DS measurement by back titration method) A sample of acetylated microfine cellulose fiber was dried and 0.50 g (A) was accurately weighed. 75 mL of ethanol and 50 mL (0.025 mol) of 0.5 N NaOH (B) were added and stirred for 3 to 4 hours. After filtering the solution, the sample was collected on the filter paper, washed with water, and dried. FT-IR analysis of the obtained sample confirmed that the absorption peak due to the carbonyl of the ester bond had disappeared, indicating that the ester bond had been hydrolyzed.

[0131] The filtrate was then used for the following back titration. The filtrate contained sodium acetate salt produced by hydrolysis and excess NaOH. The NaOH was neutralized by titration with 1N HCl. Phenolphthalein was used as the indicator.

[0132] Then, the number of moles (D) of the repeating unit of cellulose was calculated using the following formulas (i) and (ii). Formula (i): 0.025 mol (B) - (number of moles of HCl used for neutralization) = Number of moles of acetyl groups ester-bonded to hydroxyl groups of cellulose, etc. (C) Equation (ii): (molecular weight of cellulose repeating unit 162 × number of moles of cellulose repeating unit (unknown (D)) + (molecular weight of acetyl group 43 × (C)) = 0.5 g of weighed sample (A)

[0133] The DS was calculated by the following formula (iii). Formula (iii): DS=(C) / (D)

[0134] 1-3. β-crystal nucleating agent (C) C-1: A β-crystal nucleating agent having the same structure as the nucleating agent for polyolefin resins used in Example 1-1 of WO 2020 / 137179 was prepared (see formula below). [ka] C-2: NJ Star NU-100 (manufactured by New Japan Chemical Co., Ltd.) [ka]

[0135] 1-4. Other ingredients (D) D-1: PPM0127A (Toyocolor, carbon black formulation) D-2: Tinuvin 770 (BASF Japan, stabilizer (HALS)) D-3: Irganox 1010 (BASF Japan, stabilizer (hindered phenolic antioxidant) D-4: Irgafos 168 (BASF Japan, phosphorus-based antioxidant) D-5: Calcium stearate (manufactured by NOF Corporation, calcium stearate, lubricant) D-6: Urea (Mitsui Chemicals, swelling agent)

[0136] 2. Preparation of Resin Composition [Example 1] (1) Masterbatch manufacturing 13 parts by weight of the above acetylated fine cellulose fiber (absolutely dry matter, 3 parts by weight of acetyl groups, 10 parts by weight of cellulose), 5 parts by weight of D-6 (urea) as a swelling agent, 3 parts by weight of acid-modified polypropylene A-3 (maleic anhydride-modified polypropylene (MAPP)), and 1 part by weight of D-3 (hindered phenol-based antioxidant) as a stabilizer were placed in a polyethylene bag and mixed by shaking.

[0137] The obtained mixture was fed into a twin-screw kneader (manufactured by Technovel Corporation: screw diameter φ15 mm, L / D 45 (L / D is the ratio of screw length (L) to screw diameter (D)), rotors used in three places in the screw configuration) using a feeder attached to the kneader, and kneaded at 170°C to produce a masterbatch (hereinafter also referred to as "MB").

[0138] (2) Preparation of resin composition (pellets) 10.99 parts by mass of the obtained masterbatch was mixed with 89.01 parts by mass of polypropylene A-1, 0.3 parts by mass of C-1 (β-crystal nucleating agent) as a β-crystal nucleating agent, 2 parts by mass of D-1 as a carbon black preparation (0.8 parts by mass as carbon black), 0.01 parts by mass of D-2 (HALS) as a stabilizer, 0.1 parts by mass of D-3 (hindered phenol-based antioxidant), 0.1 parts by mass of D-4 (phosphorus-based antioxidant) as other antioxidants, and 0.1 parts by mass of D-5 (calcium stearate), and the mixture was kneaded at 170°C in a twin-screw kneader (manufactured by Technovel Co., Ltd.: screw diameter φ15 mm) to obtain a pellet-shaped resin composition.

[0139] [Example 2] 10.99 parts by mass of the obtained masterbatch was mixed with 89.01 parts by mass of polypropylene A-1, 0.1 part by mass of C-1 (β-crystal nucleating agent) as a β-crystal nucleating agent, 2 parts by mass of D-1 as a carbon black preparation (0.8 parts by mass as carbon black), 0.01 part by mass of D-2 (HALS) as a stabilizer, 0.1 part by mass of D-3 (hindered phenol-based antioxidant), and 0.1 part by mass of D-4 (phosphorus-based antioxidant) as another antioxidant, and the mixture was kneaded at 170°C in a twin-screw kneader to obtain a pellet-shaped resin composition.

[0140] [Example 3] In preparing the resin composition, polypropylene A-2 was used instead of polypropylene A-1, and the amount of the β-crystal nucleating agent C-1 was changed to 0.1 parts by mass. A resin composition was prepared in the same manner as in Example 1.

[0141] [Example 4] A resin composition was prepared in the same manner as in Example 1, except that the amount of the β-crystal nucleating agent C-1 was changed to 0.03 parts by mass.

[0142] [Example 5] In preparing the resin composition, a resin composition was prepared in the same manner as in Example 1, except that C-2 (Njester NU-100, manufactured by New Japan Chemical Co., Ltd.) was used instead of C-1, a β-crystal nucleating agent, and the blending amount was changed to 0.1 parts by mass.

[0143] [Example 6] 10.99 parts by mass of the obtained masterbatch, 89.01 parts by mass of polypropylene A-1, 2 parts by mass of D-1 as a carbon black formulation (0.8 parts by mass of carbon black), 0.01 parts by mass of D-2 (HALS) as a stabilizer, 0.1 parts by mass of D-3 (hindered phenol-based antioxidant), and 0.1 parts by mass of D-4 (phosphorus-based antioxidant) and 0.1 parts by mass of D-5 (calcium stearate) as other antioxidants were mixed and kneaded at 170 ° C. in a twin-screw kneader to obtain pellets. Furthermore, 100 parts by mass of the obtained pellets were mixed with 0.1 parts by mass of C-1 (β crystal nucleating agent) as a β crystal nucleating agent and kneaded at 170 ° C. in a twin-screw kneader to obtain a pellet-shaped resin composition.

[0144] [Example 7] A resin composition was prepared in the same manner as in Example 2, except that the amount of the β-crystal nucleating agent C-1 was changed to 0.03 parts by mass.

[0145] [Example 8] A resin composition was prepared in the same manner as in Example 2, except that the amount of the β-crystal nucleating agent C-1 was changed to 0.3 parts by mass.

[0146] [Comparative Example 1] A resin composition was prepared in the same manner as in Example 1, except that the β-crystal nucleating agent C-1 was not added in the preparation of the resin composition.

[0147] Comparative Example 2 A resin composition was prepared in the same manner as in Example 3, except that the β-crystal nucleating agent C-1 was not added in the preparation of the resin composition.

[0148] 3. Evaluation The obtained resin composition was injection molded under the following conditions to obtain an injection molded article (test piece). (Injection molding conditions) Injection molding machine: Toshiba Machine Co., Ltd. "EC40" Cylinder temperature: 190℃ Mold temperature: 40℃ Injection time - pressure retention time: 20 seconds (primary filling time: 1 second) Cooling time: 5 seconds The injection-molded articles obtained were evaluated as follows. The shape and size of the injection-molded articles were set as described below for each evaluation.

[0149] 3-1. Ratio R (β crystal / α crystal by wide-angle X-ray) A small square plate (30 mm x 30 mm x 2 mm (thickness)) obtained by injection molding was fixed to a sample holder under the following conditions, and the XRD profile was measured (through view) while rotating the holder. Equipment: EMPYLEAN manufactured by Spectris X-ray source:CuKα Output: 45kV, 40mA Scanning range: 5°~40° Scanning speed: 1° / min Step width: 0.0026° Detector: PIXcel3D Observed scattering vector s=1.92nm -1The peak originating from the (040) plane of the α crystal observed around (2θ=17.0°) and the scattering vector s=1.83 nm -1 The ratio R was calculated from the peak derived from the β crystal (300) plane observed near (2θ=16.2°) using the following formula. Ratio R (%) = [diffraction peak area (Pβ) derived from the β crystal (300) plane / diffraction peak area (Pα) derived from the α crystal (040) plane] × 100

[0150] 3-2. Specific gravity The specific gravity (g / cm) of the test piece obtained by injection molding 3 ) according to JIS K7112 The measurements were carried out under the following conditions. Test piece: 30mm x 5mm x 2mm (thickness) Test method: Method A (underwater substitution method)

[0151] 3-3. Tensile yield stress and tensile break strain The tensile stress at yield (MPa) and tensile strain at break (%) of the test specimens obtained by injection molding were measured under the following conditions in accordance with JIS K7161. Test piece: 5mm (width) x 75mm (length) x 2mm (thickness) Pulling speed: 20 mm / min Chuck distance: 58mm

[0152] 3-4. Flexural modulus and flexural strength The flexural modulus FM (MPa) and flexural strength (FS) (MPa) of the test pieces obtained by injection molding were measured under the following conditions in accordance with JIS K7171. Test piece: 10mm (width) x 80mm (length) x 4mm (thickness) Bending speed: 2mm / min Bending span: 64mm

[0153] 3-5. Charpy impact value Charpy impact value (kJ / m) of the test piece obtained by injection molding 2 ) was measured under the following conditions in accordance with JIS K7111. Test piece: 10mm (width) x 80mm (length) x 4mm (thickness) Notch: Machined Temperature: 23℃

[0154] 3-6. Heat distortion temperature The heat distortion temperature of a test piece (10 mm (width) × 80 mm (length) × 4 mm (thickness)) obtained by injection molding was measured in accordance with JIS K7191-1. That is, both ends of the test piece were supported in a heating bath, and a predetermined bending stress (a constant load of 0.45 MPa) was applied to the test piece using a central load rod below, while the temperature of the heating medium was raised at a rate of 2°C / min. The temperature of the heating medium when the deflection of the test piece reached a predetermined amount was taken as the heat distortion temperature.

[0155] 3-7. Checking defibration The pellet-shaped resin compositions obtained in Examples 1 to 8 and Comparative Examples 1 and 2 were confirmed to have been defibrated to nano-size under the following conditions using X-ray CT (Rigaku Corporation's high-resolution 3D X-ray microscope (nano3DX)). Pixel resolution: 0.325 μm (detector: sCMOS) Target: Cu Scan method: Step scan (1000 times) Exposure time: 28 seconds / time

[0156] The evaluation results of Examples 1 to 8 and Comparative Examples 1 and 2 are shown in Table 1. Table 2 also shows the composition of the master batch (MB) used to prepare the resin composition.

[0157] [Table 1]

[0158] [Table 2]

[0159] As shown in Table 1, the injection molded articles of Comparative Examples 1 and 2 all had a ratio R lower than 100%. Furthermore, it was found that although the flexural modulus and flexural strength were high, the impact strength and elongation were low.

[0160] In contrast, it can be seen that the injection molded articles of Examples 1 to 8 all have a ratio R higher than 100%. It can also be seen that they have high impact strength and elongation while maintaining a certain degree of flexural modulus and flexural strength.

[0161] These findings indicate that all molded articles obtained by injection molding a resin composition containing polypropylene, fine cellulose fibers, and a β-crystal nucleating agent under specified conditions have a ratio R of 100% or more, and can achieve a good balance between strength, impact strength, and elongation.

[0162] Furthermore, the inventors analyzed the state of some samples during the tensile test by optical microscope observation and confirmed that, when stress is applied, samples with a ratio R of more than 100% elongate more uniformly than samples with a ratio R of less than 100%, rather than concentrating the stress in the area where it is present, and that when stress is applied, voids are less likely to occur between the fine cellulose and polypropylene, making cracks less likely to occur. This is thought to enable a good balance between strength and impact strength / elongation. [Industrial Applicability]

[0163] According to the present invention, it is possible to provide a resin molded article that has high elongation and impact resistance while maintaining high strength.

Claims

1. A resin molded product comprising a resin composition containing polypropylene, fine cellulose fibers, and a β-crystal nucleating agent, In wide-angle X-ray diffraction measurements, the scattering vector s was 1.92±0.1 nm －１ A diffraction peak derived from the (040) plane of the α-crystal of polypropylene observed at the position of 1.83±0.1 nm －１ The diffraction peak area (Pβ) derived from the β crystal (300) plane of polypropylene observed at the position a ratio R of the diffraction peak area (Pβ) derived from the β-crystal (300) plane to the diffraction peak area (Pα) derived from the α-crystal (040) plane is 100% or more; Resin molded body.

2. The ratio R is 150% or more. The resin molded article according to claim 1.

3. The β-crystal nucleating agent has a structure represented by the following general formula (1): The resin molded article according to claim 1. 【Chemical 1】 (In general formula (1), M represents a monovalent to trivalent metal atom having a specific gravity of 4.0 or less, or a divalent or trivalent metal atom having a specific gravity of 4.0 or less and having a hydroxy group bonded thereto; a represents 1 or 2; b represents 1 or 3; x represents an integer of 1 to 3; Satisfies ax=2b. Z represents a group represented by the following general formula (2) or (3): 【Chemistry 2】 (In the general formulas (2) and (3), * represents the position at which the group is linked to the carbonyl group in general formula (1), Y represents a direct bond or an alkylene group having 1 to 4 carbon atoms; R １ ~R １０ each independently represents a hydrogen atom, a hydroxy group, a halogen atom, an alkyl group having 1 to 10 carbon atoms, a halogenated alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, or an alkenyl group having 2 to 10 carbon atoms.

4. M is lithium, sodium, potassium, magnesium, calcium, barium, aluminum, hydroxyaluminum, or dihydroxyaluminum; The resin molded article according to claim 3.

5. The fine cellulose fibers include acylated fine cellulose fibers. The resin molded article according to claim 1.

6. An injection molded article of the resin composition, The resin molded article according to claim 1.

7. A resin composition used in the preparation of the resin molded article according to any one of claims 1 to 6, When the resin composition is molded into the resin molded body, a scattering vector s of 1.92±0.1 nm is obtained by wide-angle X-ray diffraction measurement. －１ A diffraction peak derived from the (040) plane of the α-crystal of polypropylene observed at the position of 1.83±0.1 nm －１ The diffraction peak area (Pβ) derived from the β crystal (300) plane of polypropylene observed at the position a ratio R of the diffraction peak area (Pβ) derived from the β-crystal (300) plane to the diffraction peak area (Pα) derived from the α-crystal (040) plane is 100% or more; Resin composition.

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