JP6974969B2 - Method for producing cellulosic fiber reinforced resin composition and foam thereof - Google Patents

Description

The present invention relates to a cellulosic fiber reinforced resin composition and a method for producing a foam thereof.

Since cellulosic fibers are lightweight and high-strength materials, they are reinforced with thermoplastic resin compositions used in applications that require light weight and high elastic modulus and strength, such as automobile parts, aircraft parts, and building parts. It is expected to be used as a material.

For example, Patent Document 1 describes that a foam obtained from a resin composition containing a resin emulsion and cellulose nanofibers modified with a carboxy group has excellent strength. Further, in Patent Document 2, fine particles made of a copolymer containing a structural unit derived from an olefin and a structural unit derived from an unsaturated carboxylic acid are added to a dispersion containing cellulose nanofibers and an aqueous medium. , It is stated that the viscosity of the dispersion can be lowered to improve the production efficiency and handleability.

International Publication No. 2013/146847 Japanese Unexamined Patent Publication No. 2015-196790

Since cellulosic fibers contain a large amount of hydrophilic functional groups such as hydroxyl groups, there is a problem that the compatibility with the resin is low depending on the type of resin and the fibers do not disperse well in the resin composition. This undispersed cellulosic fiber causes problems such as deterioration of the surface appearance of the molded product obtained by molding the resin composition and the inability to obtain the expected mechanical properties. On the other hand, in Patent Document 1, the cellulose nanofibers are modified with a carboxy group to improve the dispersibility in vinyl acetate-based resins and the like. Further, in Patent Document 2, the dispersibility of the cellulose nanofibers is enhanced by using a copolymer containing a structural unit derived from an unsaturated carboxylic acid as a dispersant.

However, according to the findings of the present inventors, even in the molded article obtained by mixing the foam described in Patent Document 1 and the dispersion liquid described in Patent Document 2 with the thermoplastic resin and then molding, the cellulose-based fiber However, the appearance of the surface of the molded product of the resin composition was significantly inferior, and the mechanical properties such as elasticity and strength were not as high as expected.

The present invention has been made in view of the above problems of the prior art, and is a cellulose-based fiber reinforced resin capable of molding a molded product or a foam having a good surface appearance of a molded product and higher mechanical properties such as elastic modulus and strength. It is an object of the present invention to provide a method for producing a composition.

[1] A cellulosic fiber (A) dispersed in a solvent and a particulate acid-modified olefin resin (B) having an average particle size of 5 nm or more and 1000 μm or less and a melting point (Tm) of 130 ° C. or more and 180 ° C. or less. A step (1) of removing a part or all of the solvent (D) from the mixture (X) to obtain a composition (Y) containing the cellulosic fiber (A) and the acid-modified olefin resin (B). A method for producing a cellulosic fiber-reinforced resin composition, which comprises a step (2) of melt-kneading the composition (Y) and a thermoplastic resin (C) having a melting point (Tm) of 130 ° C. or higher and 280 ° C. or lower. (The mixture (X) contains 10 parts by mass to 300 parts by mass of the acid-modified olefin resin (B) with respect to 100 parts by mass of the cellulosic fiber (A)).
[2] The production according to [1], wherein the acid-modified olefin resin (B) is a dispersion (B-1) of fine particle-shaped acid-modified olefin resin having an average particle diameter of 5 nm or more and 1000 nm or less. Method.
[3] The production method according to [1], wherein the acid-modified olefin resin (B) is a powdery acid-modified olefin resin (B-2) having an average particle size of 1 μm or more and 1000 μm or less.
[4] The acid-modified olefin resin (B) is a dispersion (B-1) of fine particle olefin resin having an average particle size of 5 nm or more and 1000 nm or less, and a powder having an average particle size of 1 μm or more and 1000 μm or less. The production method according to any one of [1] to [3], which comprises both the acid-modified olefin resin (B-2) in the form of the above.
[5] The acid-modified olefin-based resin dispersion (B-1) is 0.05% by mass or more and 60% by mass or less based on the total mass of the dispersion (B-1). The production method according to [2] or [4], which comprises.
[6] Any of [1] to [5], wherein the cellulosic fiber (A) has a specific surface area of 0.1 m ² / g or more and 1000 m ² / g or less and an average fiber length of 1 μm or more and 3000 μm or less. The manufacturing method described in Crab.
[7] The composition (Y) is a composition in which the ratio of the solvent (D) to the cellulosic fiber (A) ((A) :( D)) is 50:50 or more and 100: 0 or less. 1] The production method according to any one of [6].
[8] The thermoplastic resin (C) is any one of [1] to [7], which is a thermoplastic resin selected from the group consisting of polyamide, thermoplastic polyester, thermoplastic polyurethane, polyvinyl chloride and polyolefin. The manufacturing method described in.
[9] The production method according to any one of [1] to [8], wherein the thermoplastic resin (C) is a propylene homopolymer or a propylene-ethylene copolymer.
[10] The foam of the cellulosic fiber reinforced resin composition comprising the step (3) of foaming the cellulosic fiber reinforced resin composition produced by the production method according to any one of [1] to [9]. Production method.

INDUSTRIAL APPLICABILITY According to the present invention, there is provided a method for producing a cellulosic fiber reinforced resin composition capable of forming a molded body or a foam having a higher elastic modulus and strength.

One embodiment of the present invention relates to a method for producing a cellulosic fiber reinforced resin composition, which comprises the following steps (1) and (2).
Step (1): Cellulose-based fiber (A) dispersed in a solvent and particulate acid-modified olefin-based resin (B) having an average particle size of 5 nm or more and 1000 μm or less and a melting point (Tm) of 130 ° C. or more and 180 ° C. or less. A step of removing a part or all of the solvent (D) from the mixture (X) with the cellulosic fiber (A) to obtain a composition (Y) containing the cellulosic fiber (A) and the acid-modified olefin resin (B), and a step. (2): A step of melt-kneading the composition (Y) and a thermoplastic resin (C) having a melting point (Tm) of 130 ° C. or higher and 280 ° C. or lower. It contains 10 parts by mass to 300 parts by mass of the acid-modified olefin resin (B) with respect to the fiber (A).

Another embodiment of the present invention relates to a method for producing a foam of a cellulosic fiber reinforced resin composition, which comprises the following step (3).
Step (3): Step of foaming the cellulosic fiber reinforced resin composition produced by the method including the above steps (1) and (2).

The molded product or foam produced from the cellulosic fiber-reinforced resin composition produced by the above-mentioned production method has the characteristics of high elastic modulus and strength.

1. 1. Process (1)
In the step (1), the cellulosic fiber (A) dispersed in the solvent and the particulate acid-modified olefin resin (B) having an average particle diameter of 5 nm or more and 1000 μm or less and a melting point (Tm) of 130 ° C. or more and 180 ° C. or less. ) To remove some or all of the solvent (D) from the mixture (X). The composition (Y) thus obtained contains the cellulosic fiber (A) and the acid-modified olefin resin (B), and the aggregation of the cellulosic fiber (A) is suppressed and dispersed well. It has the characteristic of being.

1-1. Mixture (X)
The mixture (X) is a mixture of the cellulosic fiber (A) dispersed in the solvent and the acid-modified olefin resin (B). The mixture (X) can be obtained by mixing the paste and the acid-modified olefin resin (B) by a known method.

The mixture (X) contains an acid-modified olefin resin (B) of 10 parts by mass or more and 300 parts by mass or less with respect to 100 parts by mass of the cellulosic fiber (A). From the viewpoint of further increasing the dispersibility of the cellulosic fiber (A) and the elasticity and strength of the molded product or foam (hereinafter, also simply referred to as “molded product or the like”) obtained from the cellulosic fiber reinforced resin composition. The amount of the acid-modified olefin resin (B) with respect to 100 parts by mass of the cellulosic fiber (A) contained in the mixture (X) is preferably 15 parts by mass or more and 250 parts by mass or less, preferably 20 parts by mass or more. It is more preferably 200 parts by mass or less.

1-1-1. Cellulose fiber (A) dispersed in a solvent
The type of the cellulosic fiber (A) is not particularly limited, but the cellulose nanofiber (cellulosic nanofiber) obtained by mechanically or chemically defibrating plants such as wood and bamboo, or pulp obtained by purifying and decolorizing them. CNF) is preferred. CNF may be lignocellulosic containing lignin.

The cellulosic fiber (A) preferably has a specific surface area of 0.1 m ² / g or more and 1000 m ² / g or less. When the specific surface area is 0.1 m ² / g or more, the elastic modulus and strength of the molded product or the like can be further increased. When the specific surface area is 1000 m ² / g or less, it is possible to suppress a decrease in dispersibility due to aggregation of the cellulosic fiber (A). From the above viewpoint, the specific surface area of the cellulosic fiber (A) ^{is more preferably 1 m 2} / g or more and 500 m ² / g or less, and further preferably 3 m ² / g or more and 300 m ² / g or less.

The specific surface area of the cellulosic fiber (A) can be a value obtained by the BET method by nitrogen adsorption.

The cellulosic fiber (A) preferably has an average fiber length of 0.1 μm or more and 3000 μm or less. When the average fiber length is 1 μm or more, the mechanical properties such as the elastic modulus and strength of the resin composition obtained by melt-kneading with the thermoplastic resin (C) in the step (2) can be further enhanced. When the average fiber length is 3000 μm or less, it is possible to suppress a decrease in dispersibility due to aggregation of the cellulosic fiber (A). From the above viewpoint, the average fiber length of the cellulosic fiber (A) is more preferably 0.5 μm or more and 2000 μm or less, and further preferably 1 μm or more and 1000 μm or less.

The cellulosic fiber (A) preferably has an average fiber diameter of 5 nm or more and 20 μm or less. When the average fiber diameter is 5 nm or more and 20 μm or less, the strength of the resin composition obtained by melt-kneading with the thermoplastic resin (C) in the step (2) can be further increased, and the cellulosic fiber (A) can be further enhanced. It is possible to suppress the decrease in dispersibility due to the aggregation of the resin. From the above viewpoint, the average fiber diameter of the cellulosic fiber (A) is more preferably 10 nm or more and 3 μm or less, and further preferably 20 nm or more and 1 μm or less.

The average fiber length and average fiber diameter of the cellulosic fiber (A) are such that the cellulosic fiber (A) contained in the mixture (X) or the cellulosic fiber (A) used as the material of the mixture (X) is dispersed with oil or the like. It is possible to prepare a test piece for observation, photograph the test piece with a body microscope, perform image analysis, and measure the test piece.

The cellulosic fiber (A) may be a modified product containing a carboxy group. The cellulosic fiber (A), which is the modified product, has high dispersibility in water that can be used as a solvent (D-1). However, the cellulosic fiber (A) is preferably an unmodified product from the viewpoint of suppressing an increase in cost and treatment time due to an increase in the number of steps.

The cellulosic fiber (A) is mixed with the acid-modified olefin resin (B) as a dispersion such as a paste containing a solvent (D-1). The solvent (D-1) is preferably one that can be easily removed from the mixture (X), and preferably water. From the viewpoint of suppressing the aggregation of the cellulosic fiber (A) during the production of the mixture (X), the dispersion such as the paste is 70% by mass or more 99.5% by mass with respect to the total mass of the dispersion such as the paste. It is preferable to contain water of 80% by mass or less, and more preferably to contain water of 80% by mass or more and 99% by mass or less.

1-1-2. Acid-modified olefin resin (B)
The acid-modified olefin resin (B) may be a particulate acid-modified olefin resin having an average particle diameter of 5 nm or more and 1000 μm or less and a melting point (Tm) of 130 ° C. or more and 180 ° C. or less.

The acid-modified olefin resin (B) having an average particle size of 5 nm or more and 1000 μm or less easily penetrates between the fibers of the cellulosic fiber (A) when mixed with the cellulosic fiber (A) and the paste containing the solvent. The dispersibility of the cellulosic fiber (A) can be enhanced.

In the present invention, the term "average particle size" simply means the volume average particle size by the laser light diffraction / scattering method.

The melting point (Tm) of the acid-modified olefin resin (B) is 130 ° C. or higher and 180 ° C. or lower. When the melting point (Tm) of the acid-modified olefin resin (B) is 130 ° C. or higher, when the solvent is removed in the step (1), when melt-kneading with the thermoplastic resin (C) in the step (2), etc. It is easy to melt the acid-modified olefin resin (B) and attach it to the surface of the cellulosic fiber (A) to suppress the aggregation of the cellulosic fiber (A), and the obtained molded product Mechanical properties such as elasticity and strength are increased. On the other hand, when the melting point (Tm) of the acid-modified olefin resin (B) is 180 ° C. or lower, the solvent is removed in the step (1) or melt-kneaded with the thermoplastic resin (C) in the step (2). A cellulose-based fiber-reinforced resin composition having good dispersibility of the cellulose-based fiber (A) can be obtained even when the temperature is set to a temperature lower than the temperature at which the cellulose is colored.

The melting point (Tm) of the acid-modified olefin resin (B) can be measured using a differential scanning calorimeter (DSC) (for example, DSC220C manufactured by Seiko Instruments). At this time, about 7 to 12 mg of the thermoplastic resin composition is sealed in an aluminum pan, heated from room temperature to 200 ° C. at 10 ° C./min, and the sample is held at 200 ° C. for 5 minutes for complete melting, and then. Cool to −50 ° C. at 10 ° C./min, allow to stand at −50 ° C. for 5 minutes, and then heat again to 200 ° C. at 10 ° C./min. The peak value temperature measured by this re-heating (second time) is defined as the melting point (Tm).

The acid-modified olefin-based resin can be produced by modifying all or part of the olefin-based resin (b) as the base polymer with an acid by a known method. For example, the olefin resin (b) is dissolved in a solvent, and an acid (particularly unsaturated carboxylic acid or a derivative thereof) and a radical generator (organic peroxide such as dialkyl peroxide) are added to the solvent for heating and stirring. The acid-modified olefin resin (B) can be produced by the above-mentioned method or a method in which the olefin resin (b), the above acid and the radical generator are supplied to the extruder and graft-copolymerized at the time of extrusion. The acid-modified olefin resin (B) suppresses the aggregation of the cellulosic fibers (A) when the solvent (D) is removed from the cellulosic fibers (A) dispersed in the solvent (D), and the cellulosic fibers (A) are suppressed. Since the interfacial adhesiveness to the fiber (A) is high, the dispersibility of the cellulosic fiber (A) can be further enhanced.

The olefin resin (b) may be a polymer containing a structural unit derived from α-olefin as a main structural unit. The olefin resin (b) may be a homopolymer of one kind of α-olefin, a copolymer of a plurality of kinds of α-olefins, or a copolymer of one or a plurality of α-olefins. It may be a copolymer with another monomer.

The olefin resin (b) may be any of a homopolymer, a random polymer, and a block polymer (elastomer) having a phase-separated sea-island structure. Of these, homopolymers and random polymers are preferable from the viewpoint of further increasing the elastic modulus of the molded body, and random polymers and block polymers are preferable from the viewpoint of further increasing the elongation of the molded body.

Examples of the α-olefins include ethylene, propylene, 1-butene, 1-pentene, 1-hexene, 1-octene, 1-decene, 1-undecene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1 -Linear α-olefins having 2 to 20 carbon atoms (preferably 2 to 15 carbon atoms, more preferably 2 to 10 carbon atoms) including octadecene and 1-ehexene, and 3-methyl. -1-butene, 3-methyl-1-pentene, 3-ethyl-1-pentene, 4,4-dimethyl-1-pentene, 4-methyl-1-hexene, 4,4-dimethyl-1-hexene, 4 It contains a branched α-olefin having 5 to 20 carbon atoms (preferably 5 to 15 carbon atoms) containing −ethyl-1-hexene, 3-ethyl-1-hexene and the like. Among these, the olefin resin (b) preferably contains a structural unit derived from ethylene, propylene, 1-butene, 1-pentene, 1-hexene, or 1-octene as a main structural unit, and ethylene or propylene. It is more preferable to include the structural unit derived from the above as the main structural unit.

Examples of the olefin resin (b) containing a structural unit derived from ethylene or propylene as a main structural unit include polyethylene, an ethylene / vinyl acetate copolymer, an ethylene / methacrylic acid copolymer, and an ethylene / methyl methacrylate. Ethylene-based polymers including copolymers and the like, and propylene-based polymers including polypropylene and the like are included.

Examples of polyethylene include low density polyethylene (LPDE), linear low density polyethylene (LLDPE), high density polyethylene (HDPE) and the like.

The acid-modified olefin resin may be modified with an acid. The acid used for the above modification is not particularly limited, but unsaturated carboxylic acid and its derivative are preferable.

Examples of polypropylene include propylene homopolymers, propylene / ethylene copolymers, propylene / 1-butene copolymers (PBR), propylene / ethylene / 1-butene copolymers (PBER) and the like. The propylene homopolymer may have any stereoregularity of isotactic, syndiotactic and atactic, or may have a plurality of blocks having any of these stereoregularities.

Examples of unsaturated carboxylic acids used for modification of the olefin resin (b) include acrylic acid, methacrylic acid, maleic acid, fumaric acid, itaconic acid, crotonic acid, citraconic acid, sorbic acid, mesaconic acid, and angelic acid. Is included. Examples of the derivatives include acid anhydrides, esters, amides, imides, metal salts, ammonium salts and the like of these unsaturated carboxylic acids. Specific examples of the above derivatives include maleic anhydride, itaconic anhydride, methyl acrylate, methyl methacrylate, ethyl acrylate, propyl acrylate, butyl acrylate, ethyl maleate, acrylamide, maleic acid amide, and sodium acrylate. And sodium methacrylate and the like. Of these, unsaturated dicarboxylic acids and derivatives thereof are preferable, and maleic acid, maleic anhydride and their metal salts and ammonium salts are more preferable. The acid-modified olefin resin (B) may be a modified product or a derivative thereof with one kind of acid, or may be a modified product or a derivative thereof with two or more kinds of acids.

The weight average molecular weight (Mw) of the acid-modified olefin resin (B) measured by gel permeation chromatography (GPC) is preferably 500 or more and 10,000,000 or more in terms of polystyrene. It is more preferably 000 or more and 5,000,000 or less, and further preferably 1,000 or more and 2,500,000 or less.

The melt flow rate (MFR) of the acid-modified olefin resin (B) measured at a temperature of 230 ° C. and a load of 2.16 kg according to ASTM D1238 is 0.3 g / 10 minutes or more and 2000 g / 10 minutes or less. It is preferably 5 g / 10 minutes or more and 1800 g / 10 minutes or less, and further preferably 10 g / 10 minutes or more and 1600 g / 10 minutes or less. When the MFR is 0.3 g / 10 minutes or more, the fluidity of the obtained composition (Y) at the time of molding is increased, so that molding is easier, and the acid-modified olefin resin (B) is a cellulosic fiber. The details between (A) are impregnated, and the elasticity and impact resistance of the injection molded product are likely to be enhanced. Further, when the MFR is 2000 g / 10 minutes or less, it is easy to increase the mechanical strength of the injection molded product.

The acid content of the acid-modified olefin resin, ^{which is determined from the peak area of 1670 cm -1 to} 1810 cm ^-1 and the calibration curve prepared separately in the IR spectrum, is preferably 0.1% by mass or more and 10% by mass or less. , 0.5% by mass or more and 8% by mass is more preferable.

The acid-modified olefin resin (B) may be a dispersion (B-1) of fine particle-like acid-modified olefin resin having an average particle size of 5 nm or more and 1000 nm or less, or an average particle size of 1 μm or more and 1000 μm. The following powdery acid-modified olefin resin (B-2) may be used.

The fine particle acid-modified olefin resin dispersion (B-1) is a dispersion in which a fine particle acid-modified olefin resin having an average particle diameter of 5 nm or more and 1000 nm or less is dispersed in a solvent (D-2). be. The solvent (D-2) for dispersing the acid-modified olefin resin is not particularly limited, but may be the same solvent as the solvent (D-1) mainly contained in the cellulosic fiber (A) dispersed in the solvent. It is preferably water.

From the viewpoint of further enhancing the dispersibility of the cellulosic fiber (A), the dispersion (B-1) is 0.5% by mass or more and 70% by mass or less with respect to the total mass of the dispersion (B-1). It is preferable to contain the acid-modified olefin resin, and it is more preferable to contain 1% by mass or more and 65% by mass or less of the acid-modified olefin resin, and 2% by mass or more and 60% by mass or less of the acid-modified olefin resin. It is more preferable to contain a resin.

The dispersion (B-1) of the acid-modified olefin resin can be prepared by a known method using, for example, another acid-modified olefin resin or a salt of a higher fatty acid as an emulsifier. For example, a method in which an acid-modified olefin resin is melt-mixed with the emulsifier, then a basic substance as a neutralizing agent and water are added and further melt-mixed, or water, a neutralizing agent and the emulsifier are mixed. After that, a dispersion (B-1) of the acid-modified olefin-based resin can be prepared by a method of further adding an acid-modified refin-based resin and melt-mixing. In either method, the average particle size of the acid-modified olefin resin contained in the dispersion (B-1) can be adjusted by appropriately adjusting the amount of the emulsifier.

The acid-modified olefin resin as the emulsifier may be a homopolymer of one kind of α-olefin, a copolymer of a plurality of kinds of α-olefins, or one or a plurality of αs. -It may be a copolymer of an olefin and another monomer. However, the acid-modified olefin resin as the emulsifier may be a polymer containing a structural unit derived from the same α-olefin as the acid-modified olefin resin for which a dispersion is to be prepared as a main structural unit.

The salt of the higher fatty acid as the emulsifier is preferably a salt of a fatty acid having 25 or more and 60 or less carbon atoms, and more preferably a salt of a fatty acid having 25 or more and 40 or less carbon atoms. These higher fatty acids can be alkali metal salts, alkaline earth metal salts, amine salts and the like. The salt of the higher fatty acid is preferably an alkali metal salt of montanic acid or oleic acid (such as sodium salt and potassium salt).

The powdery acid-modified olefin resin (B-2) is solidified and suspended by mechanically crushing the pellet-shaped acid-modified olefin resin, spraying the melted acid-modified olefin resin from a nozzle, and drying and cooling. It can be obtained by methods such as polymerization and drying. At this time, the average particle size of the powdery acid-modified olefin resin (B-2) can be adjusted by appropriately adjusting the degree of pulverization and the like.

From the viewpoint of further enhancing the dispersibility of the cellulosic fiber (A), the mixture (X) preferably contains a dispersion (B-1) of a fine particle acid-modified olefin resin, and has an elastic modulus of a molded product or the like and From the viewpoint of further enhancing the elongation, the mixture (X) preferably contains a powdery acid-modified olefin resin (B-2). From the viewpoint of enhancing the dispersibility of the cellulosic fiber (A), the elastic modulus of the molded product, strength and elongation, the mixture (X) is a dispersion (B-1) of an acid-modified olefin resin and a powder. It is preferable to contain both of the acid-modified olefin resin (B-2).

1-2. Composition (Y)
The composition (Y) is obtained by removing part or all of the solvent (D) from the mixture (X). The solvent (D) may be a solvent (D-1) derived from a paste containing a cellulosic fiber (A), but the mixture (X) is a dispersion (B-) of an acid-modified olefin resin in the form of fine particles. When 1) is contained, it may contain both a solvent (D-2) as a dispersion medium of the dispersion (B-1) and a solvent (D-1).

The solvent (D) can be removed by a known method. Examples of the method for removing the solvent (D) include a method for evaporating or volatilizing the solvent by heating or depressurization, a method for desolving the solvent by centrifugation or pressurization, and the like. These removal methods may be performed alone or in combination of two or more.

Among these, by melting the acid-modified olefin resin (B) and adhering it to the surface of the cellulosic fiber (A), it is possible to further enhance the dispersibility of the cellulosic fiber (A). Evaporation or volatilization of the solvent by heating is preferred.

The heating temperature at this time is preferably 10 ° C. lower than the melting point (Tm) of the acid-modified olefin resin (B) from the viewpoint of facilitating the melting of the acid-modified olefin resin (B), and is preferably a cellulose-based heating temperature. From the viewpoint of suppressing discoloration of the resin (A), the temperature is preferably 200 ° C. or lower.

Further, at this time, the mixture (X) is stirred from the viewpoint of suppressing the aggregation of the cellulosic fiber (A) and making it easier for the acid-modified olefin resin (B) to come into contact with the cellulosic fiber (A). It is preferable to heat while heating. ^{However, the stirring speed is preferably 1250 sec -1} or less from the viewpoint of suppressing deterioration of dispersibility due to entanglement of the cellulosic resin (A) and discoloration due to damage of the cellulosic fiber (A). Under conditions where the dispersibility of the cellulosic fiber (A) is sufficiently maintained, the mixture (X) may be heated without stirring.

Further, after heating, it is preferable to cool the mixture (X) to 100 ° C. or lower from the viewpoint of suppressing aggregation and deterioration of the cellulosic fiber (A).

When combining the solvent removal methods described above, at least 5% by weight of the liquid component contained in the mixture (X) may be removed by centrifugation or pressurization, followed by evaporation or volatilization of the solvent by heating or depressurization. preferable.

The composition (Y) obtained by removing the solvent (D) has a ratio of the solvent (D) to the cellulosic fiber (A) ((A) :( D)) of 50:50 or more and 100: 0 or less. It is preferable, and it is more preferable that it is 80:20 or more and 100: 0 or less.

2. 2. Process (2)
In the step (2), the composition (Y) obtained in the step (1) and the thermoplastic resin (C) having a melting point (Tm) of 130 ° C. or higher and 280 ° C. or lower are melt-kneaded.

2-1. Thermoplastic resin (C)
The type of the thermoplastic resin (C) is not particularly limited, and can be appropriately selected from polyamide, thermoplastic polyester, thermoplastic polyurethane, polyvinyl chloride, polyolefin and the like. The thermoplastic resin (C) may contain one type of thermoplastic resin, or may be a combination of two or more types of thermoplastic resin.

Among them, the thermoplastic resin (C) is preferably polyolefin from the viewpoint of excellent rigidity, easy recycling, and high-speed molding, and is preferably a propylene homopolymer or a propylene-ethylene copolymer. It is preferably coalesced. The propylene homopolymer may have any stereoregularity of isotactic, syndiotactic and atactic, or may have a plurality of blocks having any of these stereoregularities.

From the viewpoint of further enhancing the dispersibility of the cellulosic fiber (A) and suppressing discoloration of the cellulosic fiber (A) during molding, the melting point (Tm) of the thermoplastic resin (C) is 130 ° C. or higher and 280 ° C. or higher. It is preferably ℃ or less.

From the viewpoint of making molding easier and increasing the elastic modulus and elongation of the molded product, etc., the melt of the thermoplastic resin (C) measured at a temperature of 230 ° C. and a load of 2.16 kg in accordance with ASTM D1238. The flow rate (MFR) is preferably 0.3 g / 10 minutes or more and 500 g / 10 minutes or less. When the MFR is 1 g / 10 minutes or more, the thermoplastic resin (C) is impregnated into the details between the carbon fibers, and the elasticity and impact resistance of the injection molded product are likely to be enhanced. When the MFR is 500 g / 10 minutes or less, the mechanical strength of the thermoplastic resin (C) is high, and the mechanical strength of the injection molded product is likely to be high. From the above viewpoint, the MFR of the thermoplastic resin (C) is preferably 1 g / 10 minutes or more and 300 g / 10 minutes or less, and more preferably 5 g / 10 minutes or more and 250 g / 10 minutes or less.

2-2. The melt-kneading of the composition (Y) and the thermoplastic resin (C) can be carried out by using a kneading device including a single-screw extruder, a multi-screw extruder, a pressure kneader, and the like. When the thermoplastic resin (C) is melted, the thermoplastic resin (C) is easily impregnated into the details between the cellulose-based fibers (A), so that the thermoplastic resin (C) and the cellulosic fiber (A) are combined. The interfacial adhesion is further enhanced, and the elasticity and impact resistance of the molded body are likely to be enhanced.

The amount of the composition (Y) to be melt-kneaded is preferably 0.5% by mass or more and 90% by mass or less with respect to the total mass of the thermoplastic resin (C), and is preferably 1% by mass or more and 80% by mass or less. Is more preferable.

3. 3. Process (3)
In the step (3), the cellulosic fiber-reinforced resin composition obtained by the above-mentioned step may be foamed to form a foam.

The foam can be produced by adding a predetermined amount of an inorganic or organic chemical foaming agent to the cellulosic fiber reinforced resin composition and molding the foam.

Examples of the above-mentioned inorganic foaming agent include sodium bicarbonate (baking soda), ammonium bicarbonate, ammonium carbonate and the like.

Examples of the above organic foaming agents include N, N'-dinitroso pentamethylene tetramine (DPT), azodicarbonamide (ADCA), azobis isobutyronitrile, benzene sulfonyl hydrazide, 4,4'-. Includes oxybis (benzenesulfonyl hydrazide), toluene-sulfonyl hydrazide, p-toluene-sulfonyl semicarbazide, barium azodicarboxylate and the like.

Further, the foam may be produced by water foaming using water (steam) and a foaming agent.

Examples of the foaming agent include water of crystallization-containing inorganic substances, hygroscopic resins such as potassium ionomer, and the like.

At the time of foaming, it is desirable to use a foaming aid such as fatty acid metal salt, metal oxide, and urea together from the viewpoint of adjusting the decomposition temperature and deodorizing.

4. Molded body The cellulosic fiber-reinforced resin composition obtained in the above steps (1) and (2), or the foam obtained in steps (1) to (3) is extruded or calendar-molded. It is molded into the desired shape.

The above-mentioned molded bodies include materials for mobile vehicles such as automobiles, materials for airplanes, concrete tension materials, cables for suspension bridges, and civil engineering and construction fields such as steel frame substitute materials, and electric power fields such as power transmission line core materials. It can be preferably used for general industrial machine parts and master batches of resin compositions such as general-purpose polypropylene.

The molded product obtained by the manufacturing method of the present invention is lightweight and has excellent surface appearance and mechanical strength, and is therefore suitable as a part or member of various articles such as automobiles, motorcycles, bicycles, strollers, wheelchairs, aircrafts, and sporting goods. It can be used particularly preferably as an automobile part or member.

Such automotive parts or components include a wide range of components or components, such as door trims, door modules, instrument panels, center panels, roof panels, back door panels, and interior components such as accelerator and brake pedals. Or vertical skins such as parts, doors, fenders and back doors, horizontal skins such as bonnets and roofs, and engine room parts such as air intakes, front end modules, and fan shrouds.

Hereinafter, the present invention will be described in more detail with reference to Examples, but the scope of the present invention is not limited to the description of Examples.

1. 1. Material [Cellulose fiber (A)]
The following three types of cellulosic fibers were used.
A-1: CNF100 manufactured by Mori Machinery Co., Ltd. (approximate fiber length: approx. 100 μm, specific surface area 148 m ² / g, water content 95 wt%)
A-2: CNF250 manufactured by Mori Machinery Co., Ltd. (approximate fiber length: approx. 250 μm, specific surface area 149 m ² / g, water content 95 wt%)
A-3: CNF500 manufactured by Mori Machinery Co., Ltd. (approximate fiber length: approx. 500 μm, specific surface area 122 m ² / g, water content 95 wt%)

[Olefin-based resin (b), acid-modified olefin resin (B)]
The following 7 types of olefin resins were used.

Bi: Acid-modified polypropylene prepared by the following procedure:
Homopolymer polypropylene (manufactured by Prime Polymer Co., Ltd., trade name Prime Polypro E111G (“Prime Polypro” is a registered trademark of the company), MFR (230 ° C, 2.16 kg): 0.5 g / 10 minutes) in 100 parts by mass In contrast, 0.4 parts by mass of dialkylpolyoxide (manufactured by Nichiyu Co., Ltd., Perhexa (registered trademark) 25B) and 1.0 part by mass of powdered maleic anhydride (manufactured by Nichiyu Co., Ltd., CRYSTAL MAN (registered trademark)) were added. Premixed. This mixture was supplied to a 30 mmφ twin-screw extruder whose temperature was adjusted to 190 ° C., and the strands obtained by melt-kneading at 200 rpm were cooled in a water tank and then 40 to remove unmodified residual maleic anhydride. Vacuum dried at ° C. for 2 hours to give acid-modified polypropylene (Bi). The obtained acid-modified polypropylene (Bi) has a maleic acid content of 1.0% by mass, a weight average molecular weight (Mw) of 97,000 by gel permeation chromatography (GPC), and a differential scanning calorimeter (DSC). The measured melting point (Tm) was 162 ° C.

B-ii: Acid-modified polypropylene prepared by the following procedure:
The acid-modified polypropylene (Bi) was prepared by the same procedure except that the amount of dialkyl peroxide used for producing the acid-modified polypropylene (Bi) was changed to 1.0 part by mass and the amount of maleic anhydride was changed to 3.0 parts by mass. B-iii) was obtained. The obtained acid-modified polypropylene (B-ii) has a maleic acid content of 2.5% by mass, a weight average molecular weight (Mw) of 39,000 by gel permeation chromatography (GPC), and a differential scanning calorimeter (DSC). The measured melting point (Tm) was 162 ° C.

B-iii: Acid-modified polypropylene prepared by the following procedure:
Polypropylene used for producing acid-modified polypropylene (B-i) is a random polymer polypropylene (manufactured by Prime Polymer Co., Ltd., trade name: Prime Polypropylene B241), MFR (230 ° C., 2.16 kg): 0.5 g / 10 The acid-modified polypropylene (B-iii) was obtained by the same procedure except that the amount of dialkylpolymer was changed to 0.5 parts by mass and the amount of maleic anhydride was changed to 3.0 parts by mass. .. The obtained acid-modified polypropylene (B-iii) had a maleic acid content of 2.7% by mass, a weight average molecular weight (Mw) of 98,000 by gel permeation chromatography (GPC), and a differential scanning calorimeter (DSC). The measured melting point (Tm) was 139 ° C.

B-iv: Acid-modified polyethylene prepared by the following procedure:
The polypropylene used to prepare the acid-modified polypropylene (B-i) is made of high-density polyethylene (HDPE) (manufactured by Prime Polymer Co., Ltd., trade name: Hi-Zex 1300J ("Hi-Zex" is a registered trademark of the company), MFR (230 ° C, 2). .16 kg)): 12.0 g / 10 minutes), acid modification by the same procedure except that the amount of dialkylpolyoxide was changed to 0.1 parts by mass and the amount of maleic anhydride was changed to 2.0 parts by mass. Polyethylene (B-iv) was obtained. The obtained acid-modified polyethylene (B-iv) had a maleic acid content of 2.2% by mass, a weight average molecular weight (Mw) of 270,000 by gel permeation chromatography (GPC), and a differential scanning calorimeter (DSC). The measured melting point (Tm) was 133 ° C.

Bv: Acid-modified polyethylene prepared by the following procedure:
The polypropylene used to prepare the acid-modified polypropylene (B-i) is made of linear low-density polyethylene (LLDPE) (manufactured by Prime Polymer Co., Ltd., trade name: Ultozex 20200J (“Ultzex” is a registered trademark of the company), MFR). (230 ° C., 2.16 kg): 18.5 g / 10 minutes), the same except that the amount of dialkylpolyoxide was changed to 0.1 parts by mass and the amount of maleic anhydride was changed to 2.0 parts by mass. In the procedure, acid-modified polyethylene (Bv) was obtained. The obtained acid-modified polyethylene (Bv) had a maleic acid content of 0.8% by mass, a weight average molecular weight (Mw) of 180,000 by gel permeation chromatography (GPC), and a differential scanning calorimeter (DSC). The measured melting point (Tm) was 116 ° C.

b-vi: Propylene-butene copolymer (PBR) produced by the following procedure:
866 ml of dry hexane, 90 g of 1-butene and triisobutylaluminum (1.0 mmol) were charged at room temperature in a 2000 ml polymerizer fully substituted with nitrogen, and then the temperature inside the polymerizer was raised to 65 ° C. with propylene. The pressure in the system was pressurized and adjusted to 0.7 MPa. Next, a toluene solution in which 0.002 mmol of dimethylmethylene (3-tert-butyl-5-methylcyclopentadienyl) fluorenyl zirconium dichloride and 0.6 mmol of methylaluminoxane (manufactured by Toso Finechem) in terms of aluminum were contacted. Was added into the polymerizer, polymerized for 30 hours while maintaining the internal temperature at 65 ° C. and the internal pressure at 0.76 MPa, and 20 ml of methanol was added to terminate the polymerization. After depressurization, the polymer was precipitated from the polymerization solution in 2 L of methanol and dried under vacuum at 130 ° C. for 12 hours to obtain 12.5 g of the polymer.

The obtained propylene-butene copolymer (b-vi) has a butene content of 27.9 mol%, a maleic acid content of 0.0% by mass, and a weight average molecular weight (Mw) by gel permeation chromatography (GPC). 250,000, the melting point (Tm) measured by a differential scanning calorimeter (DSC) was 74 ° C.

b-vii: Propylene-butene-ethylene copolymer (PBER) prepared by the following procedure:
After charging 833 ml of dry hexane, 100 g of 1-butene and triisobutylaluminum (1.0 mmol) at room temperature into a 2000 ml polymerizer fully substituted with nitrogen, the temperature inside the polymerizer was raised to 70 ° C. and propylene was used. After pressurizing the pressure in the system to 0.55 MPa, the pressure in the system was adjusted to 0.76 MPa with ethylene. Next, methylaluminoxane (Tosole) with 0.001 mmol of diphenylmethylene (3-tert-butyl-5-ethylcyclopentadienyl) (2,7-di-tert-butylfluorenyl) zirconium dichloride and 0.3 mmol in terms of aluminum. -Add a toluene solution in contact with (Finechem) into the polymerizer, polymerize for 25 minutes while keeping the internal temperature at 70 ° C and the internal pressure at 0.76 MPa with ethylene, and add 20 ml of methanol to stop the polymerization. bottom. After depressurization, the polymer was precipitated from the polymerization solution in 2 L of methanol and dried under vacuum at 130 ° C. for 12 hours to obtain 137.7 g of the polymer.

The obtained propylene / butene / ethylene copolymer (b-vii) has an ethylene content of 14 mol%, a butene content of 19 mol%, a maleic acid content of 0.0% by mass, and gel permeation chromatography (GPC). The weight average molecular weight (Mw) was 350,000, and no clear melting peak could be confirmed when measured by a differential scanning calorimeter (DSC).

(Dispersion of acid-modified olefin resin (B-1))
B-1-1: Dispersion prepared by the following procedure:
A mixture of 20 parts by weight of maleic anhydride-modified polypropylene (acid content: 4 wt%, Mw: 30,000) as an emulsifier and 6 parts by weight of potassium oleate with 100 parts by weight of acid-modified polypropylene (B-i). Is continuously supplied to a 30 mmφ twin-screw extruder at a rate of 3000 g / hour, and a 20% aqueous solution of potassium hydroxide is continuously supplied at a rate of 90 g / hour from a supply port provided in the vent portion of the extruder. While continuously extruding at a heating temperature of 230 ° C. The extruded resin mixture is cooled to 110 ° C. with a static mixer with a jacket installed at the extrusion port of the extruder, and further put into warm water at 80 ° C. to obtain a dispersion (B-1-1). rice field. The solid content concentration of the obtained dispersion (B-1-1) was 45% by mass, and the average particle size of the fine particle olefin resin was 0.2 μm.

B-1-2: Dispersion prepared by the following procedure:
The same procedure was used for the dispersion (B-1-2) except that the acid-modified polypropylene (B-i) used for producing the dispersion (B-1-1) was changed to the acid-modified polypropylene (B-iii). Got The solid content concentration of the obtained dispersion (B-1-2) was 45% by mass, and the average particle size of the fine particle olefin resin was 0.2 μm.

B-1-3: Dispersion prepared by the following procedure:
A mixture of 10 parts by weight of anhydrous maleic acid-modified polyethylene (acid content: 3 wt%, Mw: 5,000) as an emulsifier and 3 parts by weight of potassium oleate with 100 parts by weight of acid-modified polyethylene (B-iv). Is continuously supplied to a 30 mmφ twin-screw extruder at a rate of 3000 g / hour, and a 20% aqueous solution of potassium hydroxide is continuously supplied at a rate of 90 g / hour from a supply port provided in the vent portion of the extruder. While continuously extruding at a heating temperature of 230 ° C. The extruded resin mixture is cooled to 110 ° C. with a static mixer with a jacket installed at the extrusion port of the extruder, and further put into warm water at 80 ° C. to obtain a dispersion (B-1--3). rice field. The solid content concentration of the obtained dispersion (B-1--3) was 45% by mass, and the average particle size of the fine particle olefin resin was 0.4 μm.

B-1-4: Dispersion prepared by the following procedure:
The dispersion (B-1--4) was prepared in the same procedure except that the acid-modified polyethylene (B-iv) used for producing the dispersion (B-1-3) was changed to the acid-modified polyethylene (B-v). Got The solid content concentration of the obtained dispersion (B-1-2) was 45% by mass, and the average particle size of the fine particle olefin resin was 0.4 μm.

B-1-5: Dispersion prepared by the following procedure:
10 parts by weight of anhydrous maleic acid-modified polypropylene (acid content: 4 wt%, Mw: 30,000, melting point (Tm): 75 ° C.) as an emulsifier with respect to 100 parts by weight of the propylene / butene copolymer (b-vi). A mixture of 3 parts by weight of potassium oleate and 3 parts by weight of potassium oleate is supplied to a 30 mmφ twin-screw extruder at a rate of 3000 g / hour, and a 20% aqueous solution of potassium hydroxide is supplied from a supply port provided in the vent portion of the extruder. While continuously supplying at a rate of 90 g / hour, the mixture was continuously extruded at a heating temperature of 230 ° C. The extruded resin mixture is cooled to 110 ° C. with a static mixer with a jacket installed at the extrusion port of the extruder, and further put into warm water at 80 ° C. to obtain a dispersion (B-1-5). rice field. The solid content concentration of the obtained dispersion (B-1-5) was 45% by mass, and the average particle size of the fine particle olefin resin was 0.4 μm.

B-1-6: Dispersion prepared by the following procedure:
Disperse in the same procedure except that the propylene / butene copolymer (b-vi) used to prepare the dispersion (B-1-5) was changed to the propylene / butene / ethylene copolymer (b-vii). A body (B-1-6) was obtained. The solid content concentration of the obtained dispersion (B-1-6) was 45% by mass, and the average particle size of the fine particle olefin resin was 0.4 μm.

B-1-7: Dispersion prepared by the following procedure:
A mixture of 6 parts by weight of maleic anhydride-modified polypropylene (acid content: 4 wt%, Mw: 30,000) and 2 parts by weight of potassium oleate with 100 parts by weight of acid-modified polypropylene (B-i) is 30 mmφ. The twin-screw extruder is supplied at a rate of 3000 g / hour, and a 20% aqueous solution of potassium hydroxide is continuously supplied at a rate of 90 g / hour from the supply port provided in the vent portion of the extruder to heat the temperature. It was continuously extruded at 230 ° C. The extruded resin mixture was cooled to 110 ° C. with a static mixer with a jacket installed at the extrusion port of the extruder, and further put into warm water at 80 ° C. to obtain a dispersion (B-1-7). .. The solid content concentration of the obtained dispersion (B-1-7) was 45% by mass, and the average particle size of the fine particle olefin resin was 0.8 μm.

(Powdered acid-modified olefin resin (B-2))
B-2-1: Powder prepared by the following procedure:
After sufficiently cooling the acid-modified polypropylene (B-ii) in liquid nitrogen, the acid-modified polypropylene is put into a high-speed rotary crusher and repeatedly pulverized by rotation until the particle size reaches a predetermined size to obtain a powdery acid-modified olefin resin. (B-2-1) was obtained. The average particle size of the obtained powdery acid-modified olefin resin (B-2-1) was 80 μm.

B-2-2: Powder prepared by the following procedure:
In the preparation of the acid-modified olefin resin (B-2-1), the number of repetitions of pulverization was adjusted to obtain a powdery acid-modified olefin resin (B-2-2). The average particle size of the obtained powdery acid-modified olefin resin (B-2-2) was 510 μm.

B-2-3: Powder prepared by the following procedure:
In the preparation of the acid-modified olefin resin (B-2-1), the number of repetitions of pulverization was adjusted to obtain a powdery acid-modified olefin resin (B-2-3). The average particle size of the obtained powdery acid-modified olefin resin (B-2-3) was 1380 μm.

[Thermoplastic resin (C)]
The following three types of thermoplastic resins were used.
C-1: Polypropylene which is a homopolymer (Prime Polymer Co., Ltd., Prime Polypro J108M: MFR = 45 g / 10 min)
C-2: Polypropylene which is a homopolymer (manufactured by Prime Polymer Co., Ltd., Prime Polypro J105G: MFR = 9.0 g / 10 min)
C-3: Polypropylene as a block polymer (Prime Polymer Co., Ltd., Prime Polypro J705UG: MFR = 9.0 g / 10 min)

2. 2. Composition (Y)
200 parts by weight of cellulosic fiber (A-1) (fiber content 10 parts by weight) with 22.2 parts by weight (solid content 10 parts by weight) of dispersion (B-1-1) and powdered acid-modified olefin Add 10 parts by weight of the based resin (B-2-1), mix uniformly, and then put into a small mixer (Laboplast Mill (registered trademark) manufactured by Toyo Seiki Co., Ltd.) to set the temperature of the equipment from 80 ° C. The water was evaporated under stirring while raising the temperature to 180 ° C. at 5 ° C./min, and after confirming that the product temperature reached 180 ° C. and no water vapor was generated from the inlet, the mixture was taken out from the mixer. The obtained solid material was crushed to a particle size of 3 mm or less before it cooled to obtain a composition (Y-1).

3. 3. Cellulose-based fiber reinforced resin composition 30 parts by weight of the composition (Y-1) and 70 parts by weight of the thermoplastic resin (C-1) are combined with a batch type twin-screw type kneader (DSM Xplore microcon). It was put into a pounder), kneaded at a set temperature of 180 ° C. and a screw rotation speed of 100 rpm for 3 minutes, transferred to an injection pot, and injection molded to obtain a dumbbell-shaped molded product specified in ISO527-2-5A.

4. Evaluation The obtained molded product was evaluated according to the following criteria.

4-1. Tensile test Tensile test is performed at a tensile speed of 50 mm / min in accordance with ISO527 to obtain a stress / strain curve, and then the tensile elasticity is calculated from the initial maximum tilt and the maximum stress initially observed during the test. The tensile strength was determined from the nominal strain at the time of fracture, and the elongation at break point was determined.

4-2. Dispersibility of Cellulose Fibers The molded product was exposed to light, and the permeation state was visually observed and evaluated according to the following criteria.
◎ No agglomerates of cellulosic fibers were confirmed ○ Agglomerates of cellulosic fibers with a particle size of about 0.5 mm or less were confirmed △ Agglomerates of cellulosic fibers with a particle size larger than 0.5 mm and about 1.0 mm or less were confirmed Confirmed × Agglomerates of cellulosic fibers larger than 1.0 mm in particle size were confirmed.

The material used for preparing the composition (Y) or the cellulosic fiber reinforced resin composition was changed as shown in Tables 3 and 4, and a molded product was prepared in the same manner and evaluated.

A mixture (X) of a cellulosic fiber (A) dispersed in a solvent and a particulate acid-modified olefin resin (B) having an average particle size of 5 nm or more and 1000 μm or less and a melting point (Tm) of 130 ° C. or more and 180 ° C. or less. ) To obtain the composition (Y) containing the cellulosic fiber (A) and the acid-modified olefin resin (B) by removing a part or all of the solvent, and the composition (Y). The cellulosic fiber-reinforced resin composition produced by the method including the step (2) of melt-kneading the thermoplastic resin (C) having a melting point (Tm) of 130 ° C. or higher and 280 ° C. or lower is the tensile elasticity of the molded product. It was excellent in rate, tensile strength and dispersibility, and it was difficult for the appearance to deteriorate due to the agglomerates of cellulosic fibers.

According to the method of the present invention, it is possible to produce a resin composition having good dispersibility of cellulosic fibers. Since the resin composition thus produced is excellent in elastic modulus and strength, it is expected to contribute to the spread and progress of the cellulosic fiber reinforced resin composition in various fields.

Claims (9)

A mixture of a cellulosic fiber (A) dispersed in a solvent and a particulate acid-modified olefin resin (B) having an average particle size of 5 nm or more and 1000 μm or less and a melting point (Tm) of 130 ° C. or more and 180 ° C. or less. A step (1) of removing a part or all of the solvent (D) from X) to obtain a composition (Y) containing a cellulosic fiber (A) and an acid-modified olefin resin (B).
The step (2) of melt-kneading the composition (Y) and the thermoplastic resin (C) having a melting point (Tm) of 130 ° C. or higher and 280 ° C. or lower is performed.
Including
The acid-modified olefin resin (B) contains a powdery acid-modified olefin resin (B-2) having an average particle size of 80 μm or more and 1000 μm or less.
A method for producing a cellulosic fiber reinforced resin composition.
(The mixture (X) contains 15 parts by mass to 300 parts by mass of the acid-modified olefin resin (B) with respect to 100 parts by mass of the cellulosic fiber (A)). The production method according to claim 1, wherein the acid-modified olefin resin (B) contains a dispersion (B-1) of fine particle-shaped acid-modified olefin resin having an average particle diameter of 5 nm or more and 800 nm or less. The production method according to claim 2, wherein the dispersion (B-1) of the acid-modified olefin-based resin is a dispersion of the acid-modified propylene-based resin. The production method according to any one of claims 1 to 3, wherein the powdery acid-modified olefin resin (B-2) is a powdery acid-modified propylene resin. The cellulosic fiber (A) has a specific surface area of 0.1 m ² / g or more and 1000 m ² / g or less, and an average fiber length of 1 μm or more and 3000 μm or less, according to any one of claims 1 to 4. Manufacturing method. The composition (Y) is a composition in which the ratio of the solvent (D) to the cellulosic fiber (A) ((A) :( D)) is 50:50 or more and 100: 0 or less . The manufacturing method according to any one of 5. The one according to any one of claims 1 to 6, wherein the thermoplastic resin (C) is a thermoplastic resin selected from a group consisting of polyamide, thermoplastic polyester, thermoplastic polyurethane, polyvinyl chloride and polyolefin. Production method. The production method according to any one of claims 1 to 7 , wherein the thermoplastic resin (C) is a propylene homopolymer or a propylene-ethylene copolymer. A method for producing a foam of a cellulosic fiber-reinforced resin composition, which comprises a step (3) of foaming the cellulosic fiber-reinforced resin composition produced by the production method according to any one of claims 1 to 8.