Thermoplastic resin composition and method for producing the same

Abstract

To provide a thermoplastic resin composition and a method for producing the same, that enable mixing a cellulose fiber with a resin without requiring modification of a cellulose, with a configuration different from conventional ones.SOLUTION: A thermoplastic resin composition forms a thermoplastic resin as a continuous phase and comprises cellulose fibers dispersed in the continuous phase. The thermoplastic resin composition is obtained by kneading the thermoplastic resin, in which the degree of modification of a hydroxy group, possessed by a cellulose constituting the cellulose fiber, is 0.5% or less (including 0%), or which serves as the continuous phase, and a fibrous material serving as a disperse phase. The fibrous material includes the cellulose fibers, and a water-soluble nonionic compound having a boiling point exceeding 100°C interposed between the cellulose fibers.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a thermoplastic resin composition and a method for producing the same, and more particularly to a thermoplastic resin composition using cellulosic fibers and a method for producing the same. [Background technology]

[0002] In recent years, cellulose fibers have been used in aqueous applications to control viscoelasticity, such as as a thickener. Meanwhile, in composite material applications, for example, cellulose fibers have been proven to be excellent reinforcing materials for resins for some time, but they have yet to be put to practical use. Thus, while cellulose fibers have been suggested to have excellent utility in composite material applications, they have not yet been put to practical use in many cases. One of the reasons for this is thought to be the strong hydrophilicity of cellulose fibers. Specifically, the cellulose contained in cellulose fibers is a polysaccharide and contains many hydroxyl groups derived from sugar chains. This makes them highly hydrophilic, making them difficult to disperse in resins and difficult to incorporate into resins. Regarding this issue, the following patent documents 1 to 3 are known. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2014-148629 [Patent Document 2] Japanese Patent Application Laid-Open No. 2016-176052 [Patent Document 3] Japanese Patent Application Publication No. 2019-189792 Summary of the Invention [Problem to be solved by the invention]

[0004] The above-mentioned Patent Document 1 discloses a technology (e.g., [Claim 1]) for chemically modifying some of the hydroxyl groups in the cellulose that constitutes the nanocellulose with alkanoyl groups having an alicyclic hydrocarbon group, with the aim of providing a novel modified nanocellulose and a resin composition containing the same (

[0011] ). The above-mentioned Patent Document 2 aims to provide a fiber-reinforced resin composition in which highly dispersible fibers are suitably combined, and a method for producing the same (

[0007] ). It discloses a fiber-reinforced resin composition ([Claim 1], etc.) that contains (A) chemically modified cellulose nanofibers and (B) a thermoplastic resin, in which the ratio R of the SP value of (A) to the SP value of (B) is 0.87 to 1.88, and the crystallinity of (A) is 42.7% or more. This disclosure mentions (

[0012] ) that the introduction of alkanoyl groups such as acetyl groups (i.e., chemically modifying the hydroxyl groups) blocks the hydroxyl groups of cellulose molecules, thereby suppressing the hydrogen bonding strength of the cellulose molecules. The above-mentioned Patent Document 3 discloses a modified cellulose nanofiber (e.g., [Claim 1]) that has a cellulose nanofiber, a polycarboxylic acid bonded to the cellulose molecules, and a polyvalent metal salt of a fatty acid having 8 to 24 carbon atoms that is chelate-bonded to carboxyl groups of the polycarboxylic acid other than the carboxyl group bonded to the cellulose molecule, with the aim of providing a modified cellulose nanofiber that can be kneaded with a thermoplastic resin in a dry powder state and has good compatibility and dispersibility in the thermoplastic resin (

[0009] ).

[0005] The techniques described in Patent Documents 1 to 3 all enable cellulose fibers to be dispersed in a resin by modifying cellulose through chemical modification of hydroxyl groups, etc. These techniques make it possible to handle cellulose fibers in a non-aqueous system, thereby solving the problems associated with resin formulation described above. As described above, various methods are currently being investigated for modifying cellulose, but it remains unclear which technologies and solutions are appropriate and practical. In order to have more options for the future, more and different options are required.

[0006] The present invention has been made in consideration of the above-mentioned circumstances, and aims to provide a thermoplastic resin composition that can be blended with cellulosic fibers without modifying the cellulose, using a configuration different from conventional ones, and a method for producing the same. [Means for solving the problem]

[0007] That is, the present invention includes the following. [1] A thermoplastic resin composition comprising a thermoplastic resin as a continuous phase and cellulosic fibers dispersed within the continuous phase, A thermoplastic resin composition characterized in that the modification rate of hydroxy groups of the cellulose constituting the cellulosic fiber is 0.5% or less (including 0%). [2] A thermoplastic resin composition obtained by kneading a thermoplastic resin that forms a continuous phase and a fibrous material that forms a dispersed phase, The thermoplastic resin composition is characterized in that the fibrous material contains cellulosic fibers and a water-soluble nonionic compound having a boiling point of over 100°C interposed between the cellulosic fibers. [3] The thermoplastic resin composition according to [2], wherein the solubility of the water-soluble nonionic compound in water is 0.5 g / 100 g H2O or more. [4] The thermoplastic resin composition according to [2], wherein the proportion of the water-soluble nonionic compound is 50% by mass or less when the total of the cellulosic fiber and the water-soluble nonionic compound is 100% by mass. [5] The thermoplastic resin composition according to [2], wherein the boiling point of the water-soluble nonionic compound is 150°C or higher and 230°C or lower. [6] The fibrous material according to [2], wherein the water-soluble nonionic compound is at least one of N-methyl-2-pyrrolidone, N,N-dimethylformamide, N,N-dimethylacetamide, and dimethyl sulfoxide. [7] The fibrous material according to [1] or [2], wherein the thermoplastic resin is at least one of polyolefin, polyamide, and polyester. [8] A kneading step is provided in which a thermoplastic resin that forms a continuous phase and a fibrous material that forms a dispersed phase are kneaded together, A method for producing a thermoplastic resin composition, characterized in that the fibrous material contains cellulosic fibers and a water-soluble nonionic compound having a boiling point of over 100°C interposed between the cellulosic fibers. [9] A fibrous material forming step for obtaining the fibrous material, [8] A method for producing a thermoplastic resin composition, wherein the fibrous substance formation process includes a water removal process for removing water from a mixture in which the cellulosic fiber, the water-soluble nonionic compound, and water coexist.

[10] The total of the cellulosic fiber and the water-soluble nonionic compound contained in the mixture is taken as 100% by mass, and the ratio of the cellulosic fiber is R C % by mass, and the proportion of the water-soluble nonionic compound is R W When expressed as mass%, R C >R W A method for producing a thermoplastic resin composition according to claim [9]. [Effects of the Invention]

[0008] According to the fibrous material and the method for producing the fibrous material of the present invention, a constitution different from that of the conventional art allows cellulosic fibers to be blended with a resin without relying on cellulose modification. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a graph showing the correlation between flexural modulus and Charpy impact strength for Experimental Examples 2 and 4 to 6. [Figure 2]1 is a graph showing the correlation between flexural modulus and Charpy impact strength for Experimental Examples 1 to 3. DETAILED DESCRIPTION OF THE INVENTION

[0010] The matters set forth herein are for illustrative purposes only and are intended to provide an illustrative description of the embodiments of the present invention, with the aim of providing what is believed to be the most effective and easily understandable explanation of the principles and conceptual features of the present invention. In this respect, it is not intended to show structural details of the present invention beyond the extent necessary for a fundamental understanding of the present invention, and the description, taken together with the drawings, will make clear to those skilled in the art how some aspects of the present invention may be actually embodied. In this specification, unless otherwise specified, the expression "XX to YY" means "XX or higher and YY or lower." Furthermore, "normal temperature" means 25°C, and "normal pressure" means 1013.25 hPa.

[0011] [1] Thermoplastic resin composition The thermoplastic resin composition of the present invention comprises a thermoplastic resin as a continuous phase and cellulosic fibers dispersed within the continuous phase, and is characterized in that the modification rate of the hydroxyl groups of the cellulose constituting the cellulosic fibers is 0.5% or less (including 0%). The cellulosic fibers may be contained in a fibrous material together with a water-soluble nonionic compound. In this case, the thermoplastic resin composition of the present invention is obtained by kneading a thermoplastic resin that forms a continuous phase with a fibrous material that forms a dispersed phase, and the fibrous material is characterized in that it contains cellulosic fibers and a water-soluble nonionic compound with a boiling point of over 100°C that is interposed between the cellulosic fibers.

[0012] (1) Cellulose fiber The above-mentioned "cellulosic fiber" refers to a fibrous material primarily composed of cellulose. In this specification, cellulosic fiber will be expressed as follows, as necessary. That is, cellulosic fiber, which is a raw material for a fibrous material and requires the coexistence of water in order to inhibit aggregation in the absence of a water-soluble nonionic compound, is also referred to as "aqueous cellulosic fiber." Furthermore, cellulosic fiber, which is a component of a fibrous material and does not require the coexistence of water because it is coexisted with a water-soluble nonionic compound, is also referred to as "non-aqueous cellulosic fiber." When the term "aqueous cellulosic fiber" is used interchangeably with "non-aqueous cellulosic fiber," it is also simply referred to as "cellulosic fiber."

[0013] The maximum length of cellulosic fibers is usually 1000 μm or less, and can be 500 μm or less, 250 μm or less, or even 100 μm or less. There is no lower limit, and a single cellulose fiber usually has a length of 1 nm or more, 3 nm or more, 5 nm or more, or even 10 nm or more. These upper and lower limits can be appropriately combined. Therefore, for example, the length can be 1 nm to 1000 μm, 3 nm to 500 μm, 5 nm to 250 μm, or 10 nm to 100 μm.

[0014] Specific examples include plant-derived fibers, pulp, cellulose microfibrils, cellulose nanofibers (hereinafter also referred to simply as "CNF"), lignocellulose (fibrous lignocellulose), etc. These may be used alone or in combination of two or more. Therefore, for example, CNF (fiber width 3 to 100 nm, aspect ratio 10 or more, length 100 μm or less) according to ISO / TS 20477:2017 is included.

[0015] The origin of the cellulosic fiber is not limited, and examples thereof include cellulosic fiber obtained from plants, cellulosic fiber produced by microorganisms (bacterial cellulose), etc. These may be used alone or in combination of two or more. Of these, the cellulosic fibers obtained from plants may be those obtained primarily from plants, or they may be those re-obtained (secondarily obtained, or more multiple times obtained, etc.) from articles formed using the cellulosic fibers obtained primarily.

[0016] The primary source of acquisition is not limited to, but may be a tree, a plant, or other plants such as bamboo or algae. The tree may be any of tall trees, shrubs, subshrubs, conifers, broad-leaved trees, evergreen trees, deciduous trees, vines, etc. The part of the tree is not limited to, and may be, for example, xylem, roots, leaves, bark, etc. The plant may be annual, biennial, perennial, erect, creeping, vine, etc. The part of the plant is not limited to, and may be, for example, stems, roots, leaves, etc. These may be used alone or in combination of two or more. Examples of reclaimed materials include cloth, woven fabric, knitted fabric, paper, etc. These may be used alone or in combination of two or more.

[0017] The plant-derived fibers may be obtained by fiberizing plants in any manner, including, for example, plant-derived fibers obtained by pulping, plant-derived fibers obtained by retting, plant-derived fibers obtained by microbial decomposition, plant-derived fibers obtained by enzymatic decomposition, etc. These may be used alone or in combination of two or more.

[0018] Among the above, the plant-derived fibers (i.e., pulp) fiberized by pulping may be mechanically treated pulp (mechanical pulp (MP), groundwood pulp (GP), refiner ground pulp (RGP), thermomechanical pulp (TMP), etc.), chemically treated pulp (chemical pulp (CP), kraft pulp (KP), sulfite pulp (SP), soda pulp (AP), etc.), pulp treated to have properties of both of these (chemical ground pulp (CGP), semi-chemical pulp (SCP), etc.), or recycled pulp. Furthermore, it may be fiber pulp or dissolving pulp (DP). These may be used alone or in combination of two or more.

[0019] As mentioned above, the source of the pulp is not limited, and it may be wood pulp or non-wood pulp. Examples of wood pulp include softwood pulp (N pulp) and hardwood pulp (L pulp). These may be used alone or in combination of two or more. Examples of non-wood pulp include linter pulp, rag pulp, linen pulp, bagasse pulp, bamboo pulp, kenaf pulp, esparto pulp, hemp pulp, and straw pulp. These may be used alone or in combination of two or more.

[0020] Furthermore, there are no limitations on whether the pulp is bleached or not. Examples include bleached hardwood kraft pulp (LBKP), unbleached hardwood kraft pulp (LUKP), bleached softwood kraft pulp (NBKP), unbleached softwood kraft pulp (NUKP), bleached hardwood sulfite pulp (LBSP), unbleached hardwood sulfite pulp (LUSP), bleached softwood sulfite pulp (NBSP), unbleached softwood sulfite pulp (NUSP), etc. These may be used alone or in combination of two or more. Furthermore, there are no limitations on whether the pulp has been beaten. That is, it may be beaten pulp or unbeaten pulp. In the case of beaten pulp, it may be beaten pulp that has undergone a loose beating process or a sticky beating process. These may be used alone or in combination of two or more. In the case of beaten pulp, there are no limitations on the degree of beating and freeness (Canadian Freeness Standard [CFS]), etc.

[0021] Among the above, dissolving pulp (DP) can be selected from the viewpoints of odor reduction and heat resistance. Dissolving pulp has a high cellulose content, and therefore a lower content of lignin, which is thermally decomposed in a lower temperature heating environment, compared to non-dissolving pulp. Therefore, the use of dissolving pulp can reduce odor compared to when dissolving pulp is not used. Furthermore, better heat resistance can be obtained.

[0022] Here, the odor refers to an odor generated by the decomposition of components constituting cellulosic fibers. For example, in a molded body obtained from a resin for molding containing a fibrous material, the resin for molding is heated (heated to a temperature at which the resin can flow) during molding, etc., which causes the decomposition of components constituting the cellulosic fibers, such as lignin. As a result, the resulting molded body may emit an odor. In contrast, when DP pulp is used as the cellulosic fiber, the amount of low-temperature decomposition components (such as lignin) contained in the DP pulp is small, or the DP pulp is substantially free of low-temperature decomposition components, so that no odor is generated even after the heating, or even if an odor is generated, the odor can be reduced.

[0023] Furthermore, excellent heat resistance can be exemplified by, for example, a reduced temperature dependence of mechanical strength. That is, as described above, in molded bodies obtained from a resin for molded bodies blended with a fibrous material, lignin and the like are decomposed. As a result, the mechanical strength of the resulting molded body may be more temperature-dependent. Specifically, the rate at which the flexural modulus decreases with increasing temperature can be cited as an example. In contrast, when DP pulp is used as the cellulosic fiber, the amount of low-temperature decomposition components (lignin, etc.) contained in the DP pulp is small or substantially absent, so the rate at which the flexural modulus decreases even after the above-mentioned heating can be reduced compared to the former.

[0024] As mentioned above, cellulosic fibers are fibrous materials primarily composed of cellulose, but the percentage of cellulose contained in the cellulosic fibers is not limited, and can be, for example, 40% by mass or more, assuming that the entire cellulosic fiber is 100% by mass. When the cellulosic fibers contain 40% by mass or more of cellulose, the effects of cellulose can be effectively obtained. This percentage is preferably 50% by mass or more, and more preferably 60% by mass or more. Alternatively, this percentage may be 100% by mass. The cellulose content in cellulosic fibers is calculated from the alkali-decomposed insoluble matter. Specifically, the sample is immersed in a 17.5% NaOH aqueous solution for two hours, followed by adding an equal volume of water to the NaOH solution and boiling for one hour. The dried residue (dried at 80°C or less) is used as the cellulose. If the sample contains lignin, the lignin is decomposed and removed by chlorination, and the cellulose content is then measured. Specifically, the sample is immersed in a solution containing sodium chlorite and acetic acid in a mass ratio of 5:1, heated to 80°C for one hour, and filtered to obtain a residue. The same procedure is repeated four times to measure the cellulose content of the residue from which the lignin has been removed. However, since the number of cellulosic fibers that make up a fibrous material is large, and it is sufficient that the resulting material be a fibrous material, there is no practical meaning in specifying the cellulose content of each cellulosic fiber. Similarly, when using cellulosic fibers derived from plants, the cellulose content varies depending on the source (type, part, etc.), and depending on the degree of purification, some fibers have a high cellulose content and others have a low cellulose content, and these can be used in combination, so there is no practical meaning in specifying the average value as long as the resulting material is a fibrous material. In addition, as long as the fibrous substance is ultimately formed, it may or may not contain hemicellulose, lignin and components derived therefrom.

[0025] Furthermore, the form of the cellulosic fiber is not limited other than being fibrous, but specifically, it is preferable that the aspect ratio is 4 or more. An aspect ratio of 4 or more makes it easier to maintain the fibrous form of the fibrous material. The aspect ratio is more preferably 5 or more, and more preferably 6 or more. The aspect ratio is usually 10,000 or less. The aspect ratio can be determined by measuring the maximum length and minimum length of the cellulosic fiber using an optical microscope or an electron microscope and calculating the ratio between them. However, since the number of cellulosic fibers that make up a fibrous material is large, and it is sufficient that the resulting fibrous material be formed, there is no practical meaning in specifying the aspect ratio of each cellulosic fiber. Similarly, when using plant-derived cellulosic fibers, the aspect ratio varies depending on the source (type, part, etc.), and depending on the processing process, some fibers have a large aspect ratio and some have a small aspect ratio, and these can be used in combination, so it is sufficient that the resulting fibrous material be formed, and there is no practical meaning in specifying the average aspect ratio.

[0026] (2) Water-soluble nonionic compounds The "water-soluble nonionic compound" is a nonionic compound that is soluble in water and has a boiling point of more than 100°C (a temperature exceeding 100°C). As described above, aqueous cellulosic fibers are fibrous materials that require the coexistence of water in order to suppress aggregation in the absence of a water-soluble nonionic compound. In this regard, the water-soluble nonionic compound can be dissolved in water coexisting with the aqueous cellulosic fibers, thereby forming a dispersed state in which the cellulosic fibers, water, and the water-soluble nonionic compound coexist. Furthermore, since the water-soluble nonionic compound has a boiling point of over 100°C, when solvent removal is performed from a state in which water and the water-soluble nonionic compound coexist, utilizing the difference in boiling points, water, which has a relatively low boiling point, can be preferentially removed. As a result, water is removed from a mixture in which cellulosic fiber, water, and the water-soluble nonionic compound coexist, and a fibrous material in which nonaqueous cellulosic fiber and the water-soluble nonionic compound coexist can be formed.

[0027] Furthermore, the water-soluble nonionic compound is a water-soluble but nonionic compound. That is, it is a compound that can be dissolved in water without ionization. Because the compound is nonionic, when water is removed from a mixture of cellulosic fibers, water, and the water-soluble nonionic compound, it remains in the gaps between the cellulosic fibers, preventing the cellulosic fibers from aggregating. As a result, the cellulosic fibers are not agglomerated and remain separate, allowing the formation of a fibrous material.

[0028] Furthermore, the fibrous material can have the above-mentioned form without chemically bonding (chemically reacting) the water-soluble nonionic compound to the cellulosic fiber or its constituent components. In other words, by utilizing an interpenetrating structure in which a water-soluble nonionic compound penetrates between aqueous cellulosic fibers, it is possible to obtain non-aqueous cellulosic fibers, i.e., fibrous materials, that can maintain a dispersed state without coexisting with water and without chemical bonding, using aqueous cellulosic fibers that cannot maintain a dispersed state unless coexisting with water as raw materials. As a result, aqueous cellulosic fibers must be handled as a liquid or fluid, while fibrous materials can be handled as a powder. Furthermore, aqueous cellulosic fibers require the coexistence of a large amount of water, whereas fibrous materials do not, which allows for a significant reduction in the mass of the cellulosic fibers when handling them. Furthermore, the elimination of water eliminates the need for refrigeration, allowing for storage at room temperature and pressure. Thus, powderization significantly improves the handleability of cellulosic fibers.

[0029] As mentioned above, the water-soluble nonionic compound inhibits the aggregation of cellulosic fibers within the fibrous material without bonding to the cellulosic fibers (no IR shift due to chemical bonding is observed). From this, it is believed that the cellulosic fibers and the water-soluble nonionic compound at least form a structure (interpenetrating structure) in which the cellulosic fibers and the water-soluble nonionic compound interpenetrate each other, and this interpenetrating structure is believed to be obtained by a coating structure in which the water-soluble nonionic compound covers the cellulosic fibers. This is derived from the fact that the fibrous material of the present invention exhibits excellent dispersibility in resin. In other words, the fibrous material of the present invention can obtain excellent dispersibility in resin by having a coating structure in which the water-soluble nonionic compound covers the outer periphery of the cellulosic fibers.

[0030] Examples of such water-soluble nonionic compounds include pyrrolidone compounds, formamide compounds, acetamide compounds, alcohol compounds, sulfoxides, ketones, etc. These may be used alone or in combination of two or more. Examples of pyrrolidone compounds include 2-pyrrolidone and 2-pyrrolidone derivatives such as N-methyl-2-pyrrolidone, which may be used alone or in combination of two or more. Examples of formamide compounds include formamide and formamide derivatives such as N,N-dimethylformamide, etc. These may be used alone or in combination of two or more. Examples of acetamide compounds include acetamide, acetamide derivatives such as 2-chloroacetamide and N,N-dimethylacetamide, and polymers such as poly-N-vinylacetamide. These may be used alone or in combination of two or more. Examples of alcohol compounds include monohydric alcohols such as n-butanol, dihydric alcohols such as ethylene glycol, diethylene glycol, and propylene glycol, and polymers such as polyethylene glycol and polypropylene glycol. These may be used alone or in combination of two or more. Examples of sulfoxides include dimethyl sulfoxide, etc. These may be used alone or in combination of two or more. Examples of ketones include diethyl ketone, etc. These may be used alone or in combination of two or more.

[0031] The water-soluble nonionic compound may be solid at room temperature and normal pressure, but is preferably liquid. When the water-soluble nonionic compound is liquid at room temperature and normal pressure, it has better solubility and dispersibility in aqueous cellulosic fibers than when it is solid. That is, a small amount of the water-soluble nonionic compound can form the interpenetrating structure described above, and a small amount of the water-soluble nonionic compound can be used to powder aqueous cellulosic fibers into nonaqueous cellulosic fibers. Among the above-mentioned water-soluble nonionic compounds, those that are solid at room temperature and normal pressure are acetamide, 2-chloroacetamide, poly-N-vinylacetamide, polyethylene glycol, and polypropylene glycol.

[0032] The water-solubility of the water-soluble nonionic compound (solubility in water) is not limited, but is preferably 0.05 g / 100 g HO or more. That is, it is preferable that the water-soluble nonionic compound can be dissolved in an amount of 1 mass % or more of the water-soluble nonionic compound relative to the aqueous cellulosic fiber contained in a mixture of aqueous cellulosic fiber and water at a solids concentration of 5 mass %. A higher solubility is preferable from the viewpoint of dispersibility. That is, from the viewpoint of excellent dispersibility when dissolved in the mixture, a higher solubility is preferable, and for example, it can be 0.5 g / 100 g HO or more, 5 g / 100 g HO or more, 50 g / 100 g HO or more, or 100 g / 100 g HO or more. On the other hand, the upper limit of the solubility in water is not limited and is substantially unlimited. That is, when the water-soluble nonionic compound is solid, it may have a solubility in twice the amount of water present, i.e., a solubility of 200 g / 100 g H2O, like acetamide, or when the water-soluble nonionic compound is liquid, it may have a solubility that allows it to be miscible with water, like N,N-dimethylacetamide.

[0033] Therefore, as mentioned above, from the viewpoint that higher solubility is preferable, among the water-soluble nonionic compounds exemplified above, liquids that are miscible with water are preferred. Therefore, 2-pyrrolidone, N-methyl-2-pyrrolidone, formamide, N,N-dimethylformamide, N,N-dimethylacetamide, dimethyl sulfoxide, ethylene glycol, diethylene glycol, and propylene glycol are preferred. These may be used alone or in combination of two or more. The solubility in water can be determined from values ​​recorded in various databases (such as MERCK INDEX (https: / / merckindex.rsc.org / )).

[0034] As mentioned above, the boiling point of the water-soluble nonionic compound may be above 100°C, but from the viewpoint of making it easier to separate from water, a larger difference in boiling point is preferable. For example, the boiling point of the water-soluble nonionic compound is preferably 125°C or higher, preferably 150°C or higher, preferably 160°C or higher, preferably 170°C or higher, preferably 180°C or higher, or preferably 190°C or higher. On the other hand, although there is no upper limit to the boiling point of the water-soluble nonionic compound, when considering the case where the compound is blended into a resin as a modifier, it is preferable that the compound can be evaporated by heating during mixing (melting and kneading, etc.), thereby reducing the content inside the resulting product, etc. From this viewpoint, the boiling point of the water-soluble nonionic compound is preferably 280°C or lower, preferably 250°C or lower, preferably 230°C or lower, and preferably 210°C or lower. These upper and lower limits can be combined as appropriate. Therefore, the boiling point of the water-soluble nonionic compound can be, for example, 125 to 280°C, 125 to 250°C, 150 to 250°C, 150 to 210°C, or 160 to 230°C.

[0035] Therefore, within the above range, examples of water-soluble nonionic compounds having a boiling point in the range of 150 to 210°C include formamide (boiling point 210°C), N-methyl-2-pyrrolidone (MNP, boiling point 202°C), ethylene glycol (boiling point 197.3°C), dimethyl sulfoxide (DMSO, boiling point 189°C), propylene glycol (boiling point 188.2°C), N,N-dimethylacetamide (DMAc, boiling point 165°C), N,N-dimethylformamide (DMF, boiling point 153°C), etc. In addition to these, examples of water-soluble nonionic compounds having a boiling point in the range of 150 to 250°C include 2-pyrrolidone (boiling point 245°C) and diethylene glycol (boiling point 244.3°C). The boiling point values ​​can be obtained from the values ​​recorded in various databases (such as MERCK INDEX (https: / / merckindex.rsc.org / )).

[0036] (3) Fibrous materials The fibrous material contains the cellulosic fiber and the water-soluble nonionic compound, and has an interpenetrating structure in which the water-soluble nonionic compound penetrates between the cellulosic fibers. That is, within the fibrous material, the cellulosic fiber and the water-soluble nonionic compound form a structure in which they interpenetrate each other (interpenetrating structure) without chemical bonding. By utilizing this interpenetrating structure, the fibrous material can be made into a non-aqueous cellulosic fiber that can maintain a dispersed state without coexisting with water, even though the aqueous cellulosic fiber is used as the raw material, without the aqueous cellulosic fiber bonding with the water-soluble nonionic compound, in other words, without denaturing the cellulose contained in the aqueous cellulosic fiber. In other words, because the fibrous material has an interpenetrating structure in which the water-soluble nonionic compound penetrates between the cellulosic fibers, it can be handled in a non-aqueous system without denaturing the cellulose, and can be blended with a resin. In the fibrous material, the ratio of the amount of the cellulosic fiber to the amount of the water-soluble nonionic compound is not limited, but the total amount of the cellulosic fiber and the water-soluble nonionic compound is taken as 100 mass %, and the proportion of the cellulosic fiber is taken as R C The proportion of water-soluble nonionic compounds is R W In terms of mass%, R C >R W That is, the ratio (R C / R W ) is R C / R W It is preferable that R is >1. C / R W By satisfying a value of >1, the amount of the water-soluble nonionic compound used can be reduced.

[0037] This ratio (R C / R W The lower limit of this ratio (R) can be 1.1 or more, 1.3 or more, 1.5 or more, 2.0 or more, 3.0 or more, 5.0 or more, or 7.5 or more. C / RW The upper limit of R can be 10,000 or less, 1,000 or less, 500 or less, 100 or less, 50 or less, 25 or less, or 15 or less. These upper and lower limits can be appropriately combined. Therefore, for example, 1.0≦R C / R W ≦10000, and 1.1≦R C / R W ≦1000, and 1.1≦R C / R W ≦500, 1.5≦R C / R W ≦100, and 2.0≦R C / R W ≦50, 3.0≦R C / R W ≦25, 5.0≦R C / R W ≦15, and 7.5≦R C / R W It can be ≦15.

[0038] The water content (moisture content) in the fibrous material can be 0%, but the fibrous material basically only needs to exist as a powder, and as long as it exists as a powder, it is not prohibited from containing water, and the water content in the fibrous material may be greater than 0%. In a fibrous material (and further, a powder, as described below), when the mass of the entire fibrous material is taken as 100% by mass, the water content can be, for example, 25% by mass or less, 20% by mass or less, 15% by mass or less, 10% by mass or less, 5% by mass or less, or 1% by mass or less. Cellulose is inherently hydrophilic. Furthermore, the water-soluble nonionic compounds that inhibit the aggregation of cellulosic fibers in fibrous materials do not exert their effect by bonding with the hydroxyl groups of cellulose. Therefore, it is believed that the hydroxyl groups of cellulose exist in the same way as in aqueous cellulosic fibers. For this reason, it is believed that fibrous materials and their aggregate powders have hygroscopic properties.

[0039] In the thermoplastic resin composition of the present invention, the fibrous material (cellulosic fiber) can be said to be used as a modifier, a carrier for additives, or the like for the thermoplastic resin. Among the above, the modifier is a component that can modify the properties of a thermoplastic resin. The fibrous material (cellulosic fiber) can be used as a modifier for fiber-reinforced resin, that is, a modifier that can improve the mechanical strength properties of a molded body obtained from the resin for molded body after blending with the thermoplastic resin that is the resin raw material for molded body. Examples of mechanical strength properties include an improvement in flexural modulus, and further examples of mechanical strength properties include an improvement in impact resistance to suppress a decrease in impact resistance that occurs as a result of an improvement in flexural modulus.

[0040] The mechanism by which the incorporation of a fibrous substance into a resin raw material for moldings results in the suppression of impact resistance degradation in the resulting resin for moldings is unclear, but the following mechanism is thought to be possible. As mentioned above, the fibrous substance contains a water-soluble nonionic compound interposed between the cellulosic fibers. Looking at this situation microscopically, it can be said that each cellulosic fiber is coated with the water-soluble nonionic compound. Furthermore, when the fibrous substance is incorporated into a resin raw material for moldings, heating during resin kneading evaporates some or all of the water-soluble nonionic compound, forming gaps between the cellulosic fibers and the matrix (e.g., resin) in which the fibrous substance is incorporated. It is thought that these gaps can reduce the number of fracture initiations compared to when the cellulosic fibers are housed in contact with the matrix. Therefore, it is thought that the incorporation of the fibrous substance into a resin raw material for moldings can suppress impact resistance degradation.

[0041] Furthermore, when the thermoplastic resin is a paint resin, the viscosity of the paint obtained from the paint resin after blending can be modified by, for example, increasing the viscosity or imparting or strengthening thixotropy. Similarly, when the thermoplastic resin is used as an adhesive resin, the viscosity of the adhesive obtained by blending the thermoplastic resin can be modified by, for example, increasing the viscosity or imparting or strengthening thixotropy.

[0042] Among the above, the carrier for additives is a carrier when adding additives to a thermoplastic resin. The type of additive is not limited, but examples include flame retardants, flame retardant assistants, fillers, colorants, antibacterial agents, antistatic agents, etc. These may be used alone or in combination of two or more.

[0043] (4)Thermoplastic resin The "thermoplastic resin" forms a continuous phase in the thermoplastic resin composition of the present invention, in contrast to the dispersed phase of the fibrous material or the cellulosic fiber. Thermoplastic resins are polymers formed by polymerizing monomers and have thermoplastic properties, and although there are no limitations on the type, examples include thermoplastic resins, thermoplastic elastomers, etc. These may be used alone or in combination of two or more types. The thermoplastic resin is not limited, but examples thereof include polyolefin, polyamide, polyester, polyurethane, polystyrene, polyvinyl chloride, etc. These may be used alone or in combination of two or more. Among these, the thermoplastic resin is preferably at least one of polyolefin, polyamide, and polyester, and more preferably polyolefin, from the viewpoints of availability and versatility in a wide variety of applications.

[0044] With regard to the above-mentioned polyolefin, the type of olefin is not limited, and examples thereof include ethylene, propylene, olefins having 4 carbon atoms (1-butene, etc.), olefins having 5 carbon atoms (3-methyl-1-butene, 1-pentene, etc.), olefins having 6 carbon atoms (3-methyl-1-pentene, 4-methyl-1-pentene, 1-hexene, etc.), olefins having 8 carbon atoms (1-octene, etc.), etc. These may be used alone or in combination of two or more. Therefore, examples of polyolefins include polyethylene, polyethylene-based copolymers, polypropylene, polypropylene-based copolymers, polybutene, polybutene-based copolymers, etc. These polymers may be used alone or in combination of two or more. Furthermore, when two or more types are used, this includes both pellets made of mixed resins and pellet mixtures.

[0045] Among the above, polyethylene includes ethylene homopolymers and copolymers of ethylene and olefins having 3 or more carbon atoms. Examples of the latter include ethylene-propylene copolymers, ethylene-butene copolymers, ethylene-hexene copolymers, and ethylene-octene copolymers. Copolymers of ethylene and other olefins may be random copolymers or block copolymers. In addition, copolymers of propylene and other olefins contain ethylene-derived structural units in an amount of 50% or more of the total number of structural units.

[0046] In addition, as polyethylene, plant-derived polyethylene (hereinafter simply referred to as "plant-derived PE") with a bio-based carbon content of 80% or more according to ISO16620-2 can be used. This bio-based carbon content is the percentage of the total carbon content. 14 This is the plant-derived carbon content (bio-based carbon content) calculated based on the proportion of C. When using plant-derived PE, a bio-based carbon content of 80% or more (or 100%) is preferred, with plant-derived PE of 85% or more, or even 90% or more being acceptable. In addition to ISO 16620-2, values ​​measured in accordance with ASTM D6866 can also be used for the bio-based carbon content. Generally, the values ​​measured in accordance with these standards are essentially the same.

[0047] Plant-derived polyethylene is a polymer whose main backbone is a structure (methylene chain) of linked methylene groups (-CH2-). The methylene chain is a structural unit derived specifically from ethylene. Plant-derived PE also includes ethylene homopolymers and copolymers of ethylene and other olefins. These may be used alone or in combination of two or more. When the plant-derived PE is a copolymer, non-ethylene-derived units (units derived from other olefins) preferably account for 50% or less (more preferably 30% or less, and even more preferably 10% or less) of the total number of constituent units. This is because a lower proportion of non-ethylene-derived units allows for a higher bio-based carbon content. In other words, plant-derived PE that has a low proportion of non-ethylene-derived units (for example, 10% or less) and is essentially an ethylene homopolymer is preferred.

[0048] Examples of other olefins include olefins having 3 carbon atoms (propylene), olefins having 4 carbon atoms (1-butene, etc.), olefins having 5 carbon atoms (3-methyl-1-butene, 1-pentene, etc.), olefins having 6 carbon atoms (3-methyl-1-pentene, 4-methyl-1-pentene, 1-hexene, etc.), olefins having 8 carbon atoms (1-octene, etc.), etc. These may be used alone or in combination of two or more.

[0049] The properties of plant-derived PE are not limited, but include a density of 0.942 g / cm 3 Preferably, the plant-derived PE is a high-density polyethylene of 35 g / 10 min or less. The MFR (230°C / 2.16 kg) of the plant-derived PE is preferably 35 g / 10 min or less, and can be 20 g / 10 min or less, or even 15 g / 10 min or less. While there are no lower limits, from the viewpoint of ease of melt-kneading, it is preferably 2 g / 10 min or more, and can be 3 g / 10 min or more. The MFR (230°C / 2.16 kg) of the plant-derived PE is a value measured in accordance with ISO 1133 or ASTM D1238. The values ​​according to these standards are usually substantially the same.

[0050] As mentioned above, the density of plant-derived PE is 0.942 g / cm 3 or more is preferable, and the density is 0.950 g / cm 3 The upper limit of the density is not limited, but it is 0.954 g / cm 3The density of polyethylene is preferably a value measured in accordance with the standards of ISO 1183 or ASTM D792. The values ​​according to these standards are usually substantially the same. The compatibility of the above-mentioned MFR and density can be adjusted by adjusting the linearity, branching amount, molecular weight, etc. of the polyethylene.

[0051] Among the above, polypropylene includes propylene homopolymers and copolymers of propylene with other olefins. Examples of the latter include propylene-ethylene copolymers, propylene-butene copolymers, propylene-hexene copolymers, and propylene-octene copolymers. Furthermore, copolymers of propylene with other olefins may be random copolymers or block copolymers. Among these, propylene-ethylene copolymers can be used due to their excellent elastomeric properties. Propylene-ethylene copolymers are block copolymer polypropylenes with ethylene blocks as the dispersed phase. That is, they are polypropylene resins with a homopolypropylene continuous phase and a dispersed phase containing polyethylene within this continuous phase. Copolymer polypropylenes with ethylene blocks as the dispersed phase are also known as impact copolymers, polypropylene impact copolymers, heterophasic polypropylenes, and heterophasic block polypropylenes. Furthermore, copolymers of propylene with other olefins have more than 50% of their total structural units derived from propylene.

[0052] The properties of the polyolefin used as the thermoplastic resin in the present invention are not limited. For example, in the case of polypropylene, the density is 0.85 to 0.95 g / cm. 3 (Furthermore, the density is 0.88 to 0.92 g / cm 3) can be used. The MFR (230°C / 2.16 kg) can be, for example, 15 g / 10 min or more. When the MFR of polypropylene is 15 g / 10 min or more (usually 100 g / 10 min or less), excellent impact resistance can be obtained. This MFR can further be 20 g / 10 min or more, or 25 g / 10 min or more. There is no upper limit, but from the viewpoint of ease of kneading, it can be 80 g / 10 min or less, or 50 g / 10 min or less. The MFR (230°C / 2.16 kg) of polyolefin is measured in accordance with ISO 1133. The compatibility of MFR and density can be adjusted by the linearity, branching amount, molecular weight, etc. of the polyolefin.

[0053] The type of the polyamide is not limited, and examples include those containing an aliphatic skeleton (commonly known as "nylon") and those consisting of only an aromatic skeleton (commonly known as "aramid"). Examples of polyamides containing an aliphatic skeleton include those synthesized by the polycondensation reaction of ω-amino acids using lactam as a raw material (e.g., PA6, PA11, PA12, etc., commonly known as "n-nylon"), and those synthesized by the co-condensation polymerization reaction of diamines and dicarboxylic acids (e.g., PA66, PA610, PA6T, etc., commonly known as "n,m-nylon"). Examples of polyamides consisting only of an aromatic skeleton include para-aramids synthesized by the co-condensation polymerization of p-phenylenediamine and terephthalic acid chloride, and meta-aramids synthesized by the co-condensation polymerization of m-phenylenediamine and isophthalic acid chloride. These may be used alone or in combination of two or more types. The above-mentioned polyamides are widely used not only as resins but also as fibers, so the thermoplastic resin composition of the present invention can also be used as a fiber raw material.

[0054] The polyesters mentioned above are not limited to specific types, and examples include those synthesized by the dehydration condensation reaction of dicarboxylic acids and diols, such as polyethylene terephthalate synthesized from terephthalic acid and ethylene glycol, polybutylene terephthalate synthesized from terephthalic acid and 1,4-butanediol, polytrimethylene terephthalate synthesized from terephthalic acid and 1,3-propanediol, polyethylene naphthalate synthesized from 2,6-naphthalenedicarboxylic acid and ethylene glycol, polybutylene naphthalate synthesized from 2,6-naphthalenedicarboxylic acid and 1,4-butanediol, and polylactic acid synthesized by polymerizing lactic acid via ester bonds. Other examples of polyesters include unsaturated polyesters containing unsaturated groups and modified polyesters modified with alkyd resins, epoxy resins, or the like. These may be used alone or in combination. The above-mentioned polyesters are widely used in resin applications, particularly in engineering plastic applications that are excellent in strength and heat resistance. In other words, the thermoplastic resin composition of the present invention can also be used as a raw material for engineering plastics.

[0055] (5) Thermoplastic resin composition The thermoplastic resin composition of the present invention is obtained by kneading a thermoplastic resin that forms a continuous phase and a fibrous material that forms a dispersed phase. That is, the thermoplastic resin composition comprises a thermoplastic resin as the continuous phase and a fibrous material dispersed within the continuous phase. The fibrous material contains cellulosic fibers and a water-soluble nonionic compound, and has an interpenetrating structure in which the water-soluble nonionic compound penetrates between the cellulosic fibers. Because of this interpenetrating structure, the cellulosic fibers can be handled in a non-aqueous system without the need for denaturation of the cellulose contained therein, and can be incorporated into a thermoplastic resin by kneading. In addition, in the fibrous material having an interpenetrating structure, the water-soluble nonionic compound is not bonded to the cellulosic fiber and may evaporate at the temperature during kneading with the thermoplastic resin. In this case, the water-soluble nonionic compound is removed from the fibrous material, and the thermoplastic resin composition of the present invention comprises a thermoplastic resin as a continuous phase and cellulosic fibers dispersed within the continuous phase. The thermoplastic resin composition exhibits suitable strength due to the thermoplastic resin being fiber-reinforced by the blended fibrous material and / or cellulosic fibers.

[0056] The amount of fibrous material and / or cellulosic fiber to be blended is not limited, but can be 50% by mass or less, 40% by mass or less, 30% by mass or less, or 20% by mass or less, with the total amount with the thermoplastic resin being 100% by mass. The amount of this fibrous material and / or cellulosic fiber can further be 0.5% by mass or more, 1% by mass or more, 3% by mass or more, or 5% by mass or more. These upper and lower limits can be appropriately combined, and can be, for example, 0.5 to 50 mass %, 1 to 40 mass %, 3 to 30 mass %, or 5 to 20 mass %.

[0057] Regarding the performance of a thermoplastic resin composition, the "strength" relating to the mechanical strength properties of the resulting molded article can usually be evaluated by elasticity, and the elasticity can be expressed as a flexural modulus measured by a flexural elasticity test (JIS K7171, ISO 178, ASTM D790). The flexural modulus is not limited, but can be 1000 MPa or more, 1100 MPa or more, 1150 MPa or more, or 1200 MPa or more. This flexural modulus can be 4000 MPa or less, 3500 MPa or less, 3000 MPa or less, or 2500 MPa or less. These upper and lower limits can be appropriately combined. Therefore, for example, it can be 1000 to 4000 MPa, 1100 to 3500 MPa, 1150 to 1600 MPa, or 1200 to 1550 MPa.

[0058] Regarding the performance of a thermoplastic resin composition, the "rigidity" related to the mechanical strength properties of the resulting molded article can usually be evaluated by impact resistance, which can be expressed as an impact resistance value measured by a Charpy impact test (JIS K7111-1, ISO 179-1, ASTM D6110). Impact resistance is not limited, but is 10kJ / m 2 It can be more than 12kJ / m 2 It can be more than 15kJ / m 2 It can be more than 18kJ / m 2 This impact resistance value can be further increased to 45 kJ / m or more. 2 can be less than 40 kJ / m 2 can be less than 35 kJ / m 2 These upper and lower limits can be appropriately combined. Therefore, for example, 10 to 45 kJ / m 2 and can be set to 12 to 40 kJ / m 2 can be set to 18 to 35 kJ / m 2 It can be said that:

[0059] [2] Method for producing thermoplastic resin composition The method for producing a thermoplastic resin composition of the present invention includes a kneading step. The "kneading step" is a step of kneading a thermoplastic resin that forms a continuous phase and a fibrous material that forms a dispersed phase. The fibrous material used in the kneading step contains cellulosic fibers and a water-soluble nonionic compound having a boiling point of over 100° C., which is interposed between the cellulosic fibers. In this fibrous material, the water-soluble nonionic compound penetrates between the cellulosic fibers without chemical bonding, thereby forming an interpenetrating structure.

[0060] The water-soluble nonionic compound contained in the fibrous material forms an interpenetrating structure with the cellulosic fiber, thereby coating the hydroxyl groups of the cellulose contained in the cellulosic fiber and suppressing the hydrophilicity of the cellulosic fiber. Therefore, in the kneading process, the fibrous material, although made from aqueous cellulosic fiber as the raw material, can behave as a non-aqueous cellulosic fiber that can maintain a dispersed state without coexisting with water, and can be dispersed approximately uniformly in the thermoplastic resin that serves as the continuous phase.

[0061] In the kneading step, the method for kneading the thermoplastic resin and the fibrous material is not limited, and examples thereof include a melt-kneading method using a kneader such as a single-screw kneader extruder, a twin-screw kneader extruder, or a multi-screw kneader extruder; a method in which each component is dissolved or dispersed in a solvent or solvent and then the solvent or solvent is removed by heating; and a dry blending method in which each component is stirred and mixed at a temperature at which the resin components do not melt to form a homogeneous state. Of these, the melt-kneading method using a kneader is preferred from the viewpoint of workability. Furthermore, the thermoplastic resin composition obtained by melt-kneading can be, for example, pelletized and directly extruded into a mold or the like to form a molded product.

[0062] In the kneading step, the thermoplastic resin and the fibrous material may be kneaded under any temperature conditions, but the temperature can usually be set within an appropriate range depending on the softening temperature or melting temperature of the thermoplastic resin used. For example, when the thermoplastic resin is polyolefin, the temperature can be 160° C. or higher, 180° C. or higher, or 200° C. or higher. There is no upper limit, but it can usually be 250° C. or lower, or 200° C. or lower. When the thermoplastic resin is polyamide or polyester, the temperature can be 180° C. or higher, 200° C. or higher, or 220° C. or higher. There is no upper limit, but it is usually 280° C. or lower, or 270° C. or lower. These upper and lower limits can be appropriately combined, and can be, for example, 160 to 280°C, 180 to 270°C, or 200 to 250°C.

[0063] The method for producing a thermoplastic resin composition may include a fibrous material forming step. The "fibrous material forming step" is a step of obtaining the above-mentioned fibrous material. In this fibrous material forming step, a mixture in which cellulosic fiber, a water-soluble nonionic compound, and water are present together can be formed. In forming the fibrous material, the method for forming the mixture is not limited, but for example, it can be obtained by (1) mixing aqueous cellulosic fiber (including cellulosic fiber and water) with a water-soluble nonionic compound, (2) mixing cellulosic fiber, water, and a water-soluble nonionic compound, or (3) mixing cellulosic fiber with a mixture of a water-soluble nonionic compound and water. In the case of (1) above, the water-soluble nonionic compound can be added to and mixed with the aqueous cellulosic fiber, or a mixture of the water-soluble nonionic compound and water can be added to and mixed with the aqueous cellulosic fiber. These can be used alone or in combination of two or more.

[0064] The fibrous material forming step may include a water removal step. The "water removal step" is a step of removing water from a mixture in which cellulosic fibers, a water-soluble nonionic compound, and water are present together. The cellulosic fiber and the water-soluble nonionic compound are as described above.

[0065] In the water removal step, water may be removed by any method, and examples of the removal method include removal by evaporation (evaporative removal), removal by centrifugation (centrifugal removal), removal by compression (compressive removal), etc. These may be used alone or in combination of two or more. Among these, evaporation is preferred. As mentioned above, the water-soluble nonionic compound is a nonionic compound that is water-soluble and has a boiling point of more than 100° C. Therefore, by utilizing evaporation, it is possible to preferentially remove water, which has a boiling point lower than that of the water-soluble nonionic compound, while leaving the water-soluble nonionic compound in the mixture.

[0066] In the water removal step, all of the water contained in the mixture may be removed, but not all of it. That is, the water removal rate may be 100%, but it may also be less than 100%. This is because the moisture content of the resulting fibrous material may be 0%, but as long as it exists as a powder, the moisture content may be greater than 0%. Specifically, as described above, when the total mass of the resulting fibrous material is taken as 100% by mass, the water content can be 25% by mass or less, 20% by mass or less, 15% by mass or less, 10% by mass or less, 5% by mass or less, or 1% by mass or less.

[0067] The water removal step can be carried out simultaneously with the mixture formation step described above, or can be carried out substantially after the mixture formation step, i.e., the mixture may be formed before the water removal step or simultaneously with the water removal step. The simultaneous execution of the mixture-forming step and the water-removing step refers to a case where the formation of the mixture and the removal of water from the mixture proceed simultaneously, for example, a case where the components constituting the mixture are added during the water-removing step. That is, a water-soluble nonionic compound may be added to a mixture of aqueous cellulosic fibers and water while simultaneously removing water. Another example is a mixture of aqueous cellulosic fibers and water while simultaneously removing water. Examples of the latter include, for example, when dry pulp is used as a raw material for aqueous cellulosic fibers, a process in which water is added to more reliably dissociate the cellulosic fibers, or a process in which water is added while beating to increase the degree of beating (a process to increase the degree of defibration). In this way, by improving the dissociation state of the cellulosic fibers, mutual penetration by the water-soluble nonionic compound can be more reliably achieved.

[0068] In addition, an embodiment in which the mixture is formed simultaneously with the water-removing step (the water-removing step and the mixture-forming step proceed simultaneously) includes a case in which components constituting the mixture are added during the water-removing step, such as a case in which a water-soluble nonionic compound is continuously added during the water-removing step. Furthermore, when the water content of the aqueous cellulose fiber used as a raw material is reduced, a pretreatment can be performed by adding water to more reliably dissociate the cellulose fibers contained in the aqueous cellulose fiber. By using a mixture in which the dispersibility of the cellulose fibers contained in the aqueous cellulose fiber is improved, mutual penetration by the water-soluble nonionic compound can be more reliably achieved.

[0069] The amount of water-soluble nonionic compound contained in the mixture is not limited as long as it results in the aforementioned fibrous material, but it can also be blended in the mixture so that the resulting fibrous material contains cellulosic fiber and water-soluble nonionic compound. That is, as described above, the total of the cellulosic fiber and the water-soluble nonionic compound is 100 mass %, and the proportion of the cellulosic fiber is R C The proportion of water-soluble nonionic compounds is R W In terms of mass%, R C / R W>1 is preferred, and the lower limit can be 1.1 or more, 1.3 or more, 1.5 or more, 2.0 or more, 3.0 or more, 5.0 or more, or 7.5 or more. On the other hand, this ratio (R C / R W ) can be 10,000 or less, 1,000 or less, 500 or less, 100 or less, 50 or less, 25 or less, or 15 or less. These upper and lower limits can be appropriately combined. For example, 1.0≦R C / R W ≦10000, and 1.1≦R C / R W ≦1000, and 1.1≦R C / R W ≦500, 1.5≦R C / R W ≦100, and 2.0≦R C / R W ≦50, 3.0≦R C / R W ≦25, 5.0≦R C / R W ≦15, and 7.5≦R C / R W It can be ≦15. However, for example, after removing water by evaporation, a step of removing the water-soluble nonionic compound can be provided so that the amount of the water-soluble nonionic compound is appropriate. When such a water-soluble nonionic compound removal step is provided, a large amount of the water-soluble nonionic compound can be blended regardless of the blending ratio.

[0070] Any device may be used to mix the mixture, and examples thereof include a mixer, kneader, extruder, kneader, and mixer (such as a high-speed fluid mixer, paddle mixer, or ribbon mixer). These may be used alone or in combination of two or more types. When two or more types are used, they may be operated continuously or batchwise (batchwise). Furthermore, the raw materials may be mixed all at once, or may be added and mixed in multiple batches (multi-stage blending). When these devices have screws, they may be single-shaft, twin-shaft, or multi-shaft, with twin-shaft being preferred.

[0071] When evaporation is used to remove water in the water removal step, the process may be carried out under any conditions, including atmospheric pressure, elevated pressure, reduced pressure, or a combination of these. Among these, evaporation under reduced pressure (evaporation under reduced pressure) is preferred from the viewpoint of energy costs, since it allows the heating temperature to be lowered. The reduced pressure conditions can be set within an appropriate range depending on the water-soluble nonionic compound used. The heating conditions can also be set within an appropriate range depending on the water-soluble nonionic compound used, and can be, for example, 90°C or higher, 100°C or higher, or 120°C or higher. The upper limit is not limited, but is usually 250°C or lower, or 200°C or lower. These upper and lower limits can be appropriately combined. Therefore, for example, the temperature can be 90 to 250°C, 100 to 200°C, or 120 to 200°C.

[0072] If necessary, a water-soluble nonionic compound removal step can be provided to remove the water-soluble nonionic compounds. The removal of the water-soluble nonionic compounds may be performed on only a part or all of the water-soluble nonionic compounds contained in the fibrous material. When the water-soluble nonionic compound is removed, the thermoplastic resin composition can have a configuration in which the cellulosic fibers contained in the fibrous material remain dispersed as fibrous material within the continuous phase of the thermoplastic resin, thereby allowing the cellulosic fibers to be dispersed within the continuous phase of the thermoplastic resin.

[0073] The water-soluble nonionic compound removal step can be carried out simultaneously with the mixture formation step. That is, the temperature conditions in the kneading step may exceed the boiling point of the water-soluble nonionic compound contained in the fibrous material. In this case, since the water-soluble nonionic compound is not chemically bonded to the cellulosic fiber, it is evaporated under the temperature conditions during kneading and removed from the fibrous material. The water-soluble nonionic compound removing step can also be carried out after the water removing step.

[0074] The water-soluble nonionic compound may be removed by any means, but can also be removed by evaporation, as in the case of removing water. In this case, after the water has been removed by evaporation, the water-soluble nonionic compound can be removed by evaporation continuously. Furthermore, when a water-soluble nonionic compound removal step is provided, the fibrous material can contain a larger amount of water-soluble nonionic compound regardless of the blending ratio (content ratio) of the cellulosic fiber and the water-soluble nonionic compound described above.

[0075] Alternatively, in addition to the water removal step, mixture formation step, and other steps, a purification step of purifying the cellulosic fibers may be included. The purification step is a step of purifying the cellulosic fibers, and may be, for example, a step of increasing the cellulose concentration or a step of increasing the degree of beating. The purification step is preferably carried out before the mixture formation step. [Example]

[0076] The present invention will be specifically described below with reference to examples. [1] Manufacturing of fibrous materials (1)Each raw material component (1-1) Microfibrillated fiber (microfibrous cellulose), solid content concentration 14.4% by mass, product name "Cerish KY110N" (manufactured by Daicel Miraize Co., Ltd.) (1-2) Water-soluble nonionic compounds "NMP": N-methyl-2-pyrrolidone "DMF": N,N-dimethylformamide "DMAc": N,N-dimethylacetamide "DMSO": dimethyl sulfoxide

[0077] (2)Equipment used We have prepared an apparatus with one reaction vessel capable of performing mixing, kneading, and vacuum distillation individually or simultaneously within the reaction vessel. The mixing and kneading operations of this apparatus include mixing the contents of the reaction vessel using a three-pronged stirrer (motor performance: 0.75 kW, 4P, 200 V, 60 Hz, 39 A, 1800 rpm / min) and heating the interior of the reaction vessel to a maximum of approximately 300°C using a heater jacket wrapped around the outer periphery of the reaction vessel. Furthermore, the apparatus is capable of performing distillation operations by reducing the pressure inside the reaction vessel to a maximum of approximately 0.1 MPa using a connected vacuum pump and heating the interior of the reaction vessel to a maximum of approximately 80°C using a heater jacket wrapped around the outer periphery of the reaction vessel.

[0078] (3) As shown in Table 1, NMP, DMF, DMAc, and DMSO were charged into a reaction vessel so that the solid content of the cellulosic fiber was 1 part by mass, 10 parts by mass, or 1,000 parts by mass, assuming 1 part by mass of each water-soluble nonionic compound. Then, the reaction vessel was vacuum-evaporated to 0.072 MPa, heated to 120°C with a stirrer rotating at 20 Hz, and vacuum evaporation was performed. After substantially all of the water contained in the charged raw materials had evaporated, the apparatus was stopped, and the reaction product, a powder consisting of an aggregate of the fibrous materials of Experimental Examples 1 to 6, was removed from the reaction vessel. In all cases, these reaction products were powders having a soft texture, i.e., powders consisting of an aggregate of the fibrous materials.

[0079] (4) Measurement of moisture content of fibrous materials The moisture content of the fibrous materials (powders that are aggregates of fibrous materials) of Experimental Examples 1 to 6 was measured using an infrared moisture meter (model "FD-720", manufactured by Kett Electric Laboratory Co., Ltd.) at a drying temperature of 105°C and a drying time of 5 hours.The moisture content of all fibrous materials was found to be 0% (rounded to the nearest integer).

[0080] [2] Preparation of molded body for evaluation of modification Each of the fibrous materials obtained in [1] above in Experimental Examples 1 to 6 was mixed with the following polyolefin resin (feeding into a twin-screw kneading extruder (manufactured by Technovel Co., Ltd., model "KZW15TW-30 / 45MG-NH", screw diameter 15 mm, L / D=45) and mixed at an extrusion rate of 0.6 kg / hour and a screw rotation speed of 200 rpm), followed by injection molding to obtain evaluation molded articles for Experimental Examples 1 to 6. The blending amounts of the fibrous materials are as shown in Table 1. As the polyolefin resin, a propylene block copolymer (manufactured by Japan Polypropylene, product name "Novatec BC6", MFR 2.7 g / 10 min, melting point 163° C.) was used.

[0081] [3] Evaluation of molded products for evaluation (1) Measurement of bending modulus Tensile tests were conducted in accordance with ISO 527-1 using each evaluation molded article obtained in [2] above. The results are shown as "flexural modulus" in Table 1. Furthermore, an evaluation molded article consisting of only polyolefin resin (block PP) without any fibrous composite was molded by injection molding, and when this was measured in the same manner as above, the flexural modulus was found to be 902 (MPa). [Test conditions] Testing equipment: Autograph 50kN (Shimadzu Corporation, model "AGS-X") Test temperature: 23℃ Specimen shape: ISO multipurpose specimen Tensile speed (elastic modulus measurement): 1 mm / min Drying conditions: Vacuum drying at 23°C for 24 hours or more

[0082] (2) Charpy impact strength measurement A Charpy impact strength test (based on ISO 179) was carried out using each of the evaluation molded articles obtained in [2] above. Test pieces with a notch (Type A) were used, and the test was carried out at a test temperature of 23°C using the edgewise test method. The results are shown as "Charpy" in Table 1. Furthermore, evaluation molded articles consisting of only polyolefin resin (block PP) without any fibrous composite compound were injection molded, and when these were measured in the same manner as above, the Charpy impact strength was 59.0 (kJ / m 2 ) was.

[0083] [Table 1]

[0084] [4] Effects of the embodiment (1) Figure 1 shows a graph comparing the results of Experiments 2 and 4 to 6, in which the ratio of water-soluble nonionic compound to cellulosic fiber was 1:10, based on the results of Table 1. Figure 1 shows that NMP, DMF, DMAc, and DMSO, all of which are water-soluble nonionic compounds, can be easily dispersed in the matrix resin, and that the addition of cellulosic fiber significantly improves the flexural modulus.

[0085] In addition, when cellulosic fibers are generally blended into a resin for the purpose of modifying the resin, the resulting modified resin has a significantly improved flexural modulus, but a significant decrease in impact resistance, resulting in a trade-off (a trade-off between flexural modulus and impact resistance). In this regard, Experimental Examples 2, 4, and 6 maintained high impact resistance (high Charpy impact strength obtained at the same flexural modulus) throughout the entire range of practical flexural modulus values ​​of 1900 MPa or less. In particular, when NMP (Experimental Example 2) or DMF (Experimental Example 4) was used as the water-soluble nonionic compound, it was found that higher impact resistance could be maintained than when DMAc (Experimental Example 5) or DMSO (Experimental Example 6) was used as the water-soluble nonionic compound. In other words, it was found that the trade-off between flexural modulus and impact resistance was more effectively suppressed. Furthermore, in Figure 1, the plot data for NMP (Experimental Example 2) and the plot data for DMF (Experimental Example 4) show a flexural modulus of 1513 MPa and a Charpy impact strength of 19.47 kJ / m. 2 However, it can be seen that in the region of 1513 MPa or less, which can be said to be a more practical range of flexural modulus, Experimental Example 2 can most effectively maintain Charpy impact strength.

[0086] (2) Figure 2 shows a graph comparing Experimental Examples 1 to 3, which are examples using a fibrous material that utilizes NMP, the water-soluble nonionic compound that exhibited the most excellent effect in (1) above, in which the water-soluble nonionic compound:cellulosic fiber ratio was 1:1 to 1:1000. From these results, it can be seen that Experimental Example 3 is most effective in improving the flexural modulus. On the other hand, it can be seen that Experimental Example 1 is most effective in maintaining the Charpy impact strength. In this regard, it can be seen that Experimental Example 2 is most effective in suppressing the trade-off between flexural modulus and impact resistance (it can have the highest Charpy impact strength for the same flexural modulus).

[0087] The present invention is not limited to the specific examples described above, and various modifications can be made within the scope of the present invention depending on the purpose and application.

[0088] The foregoing examples are for illustrative purposes only and are not to be construed as limiting the invention. While the invention has been described with reference to exemplary embodiments, it is understood that the language used in describing and illustrating the invention is descriptive and exemplary, rather than limiting. As detailed herein, changes may be made within the purview of the appended claims without departing from the scope or spirit of the invention in its form. While the description of the invention has referred to specific structures, materials, and examples, it is not intended that the invention be limited to the disclosure set forth herein; rather, the invention is intended to cover all functionally equivalent structures, methods, and uses within the scope of the appended claims.

Claims

1. A thermoplastic resin composition comprising a thermoplastic resin as a continuous phase and cellulosic fibers dispersed within the continuous phase, A thermoplastic resin composition characterized in that the modification rate of hydroxy groups of the cellulose constituting the cellulosic fiber is 0.5% or less (including 0%).

2. A thermoplastic resin composition obtained by kneading a thermoplastic resin that forms a continuous phase and a fibrous material that forms a dispersed phase, The thermoplastic resin composition is characterized in that the fibrous material contains cellulosic fibers and a water-soluble nonionic compound having a boiling point of over 100°C interposed between the cellulosic fibers.

3. The solubility of the water-soluble nonionic compound in water is 0.5 g / 100 gH ２ The thermoplastic resin composition according to claim 2, wherein the molecular weight is 0 or more.

4. 3. The thermoplastic resin composition according to claim 2, wherein the proportion of the water-soluble nonionic compound is 50% by mass or less when the total of the cellulosic fiber and the water-soluble nonionic compound is 100% by mass.

5. 3. The thermoplastic resin composition according to claim 2, wherein the boiling point of the water-soluble nonionic compound is 150°C or higher and 230°C or lower.

6. 3. The thermoplastic resin composition according to claim 2, wherein the water-soluble nonionic compound is at least one of N-methyl-2-pyrrolidone, N,N-dimethylformamide, N,N-dimethylacetamide, and dimethyl sulfoxide.

7. 3. The thermoplastic resin composition according to claim 1, wherein the thermoplastic resin is at least one of polyolefin, polyamide, and polyester.

8. The method includes a kneading step of kneading a thermoplastic resin that forms a continuous phase and a fibrous material that forms a dispersed phase, A method for producing a thermoplastic resin composition, characterized in that the fibrous material contains cellulosic fibers and a water-soluble nonionic compound having a boiling point of over 100°C interposed between the cellulosic fibers.

9. a fibrous material forming step for obtaining the fibrous material, The method for producing a thermoplastic resin composition according to claim 8, wherein the fibrous substance formation process includes a water removal process for removing water from a mixture in which the cellulosic fiber, the water-soluble nonionic compound, and water coexist.

10. The total amount of the cellulosic fiber and the water-soluble nonionic compound contained in the mixture is taken as 100 mass %, and the proportion of the cellulosic fiber is R Ｃ % by mass, and the proportion of the water-soluble nonionic compound is R Ｗ When expressed as mass%, R Ｃ >R Ｗ The method for producing a thermoplastic resin composition according to claim 9, wherein

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