JP7250602B2 - Method for producing resin composition - Google Patents

Description

The present invention relates to a method for producing a resin composition.

Conventionally, petroleum-derived plastic materials, which are a finite resource, have been widely used, but in recent years, technologies that have a low impact on the environment have come into the spotlight. Materials using cellulose have attracted attention.

For example, Patent Literature 1 discloses a technique for uniformly dispersing chemically treated cellulose fibers in a hydrophobic thermoplastic resin.

Patent No. 5613996

However, it is generally difficult to disperse hydrophilic cellulose in a resin even if the cellulose is chemically treated, and the mechanical strength of the molded product obtained by molding the obtained resin composition is always satisfactory. it wasn't to the extent.

Accordingly, the present invention provides a method for producing a resin composition in which modified cellulose (hereinafter referred to as modified cellulose) in which specific substituents are bonded to cellulose via ether bonds is dispersed in a resin. Regarding.

That is, the present invention relates to the following [1] to [2].
[1] A method for producing a resin composition, comprising the following steps (1) and (2).
Step (1): Step of mixing a dispersion of modified cellulose dispersed in an organic solvent with an olefin-based resin Step (2): Kneading the mixture obtained in Step (1), and removing an organic solvent from the mixture Removing step [2] A resin composition produced by the method for producing a resin composition according to [1] above.

According to the present invention, it is possible to provide a method for producing a resin composition in which modified cellulose is dispersed in a resin.

<Method for producing resin composition>
The production method of the present invention is a method for producing a resin composition having the following steps (1) and (2).
Step (1): A step of mixing a dispersion of modified cellulose in an organic solvent with an olefin resin.
Step (2): a step of kneading the mixture obtained in step (1) and removing the organic solvent from the mixture.

Although the mechanism by which the production method of the present invention exerts such effects is not clear, a mixture containing modified cellulose, an organic solvent, and an olefin resin is kneaded to remove the organic solvent, whereby the modified cellulose aggregates together. Since the resin composition is produced without the time to do so, it is presumed that a resin composition in which the modified cellulose is maintained in a highly dispersed state can be produced.

[Step (1)]
Step (1) is a step of mixing a dispersion of modified cellulose in an organic solvent with an olefin resin.

[Modified cellulose]
The modified cellulose in the present invention is obtained by bonding a specific substituent to cellulose through an ether bond. In the present specification, "bonded via an ether bond" means a state of bonding to an oxygen atom obtained by removing a hydrogen atom from a hydroxy group of cellulose.

(average fiber diameter)
The average fiber diameter of the modified cellulose is preferably 5 μm or more from the viewpoints of improving the mechanical strength of the resin composition, improving the handleability of the modified cellulose, facilitating availability, and reducing the cost. , more preferably 7 μm or more. Although the upper limit is not particularly set, it is preferably 100 µm or less, more preferably 70 µm or less, from the viewpoint of improving the handleability of the modified cellulose and the mechanical strength of the resin composition. In addition, in this specification, the average fiber diameter of the modified cellulose is measured by the method described in Examples below.

Also, the modified cellulose may have a fine average fiber diameter. For example, the modified cellulose can be pulverized by treatment using a high-pressure homogenizer or the like in an organic solvent. The average fiber diameter of the refined modified cellulose may be, for example, about 1 to 500 nm, and from the viewpoint of improving the mechanical strength of the resin composition, it is preferably 3 nm or more, more preferably 10 nm or more, From the viewpoint of improving the handleability of the modified cellulose and the dimensional stability of the resin composition, it is preferably 300 nm or less, more preferably 200 nm or less.

(substituent)
Preferred substituents possessed by the modified cellulose are preferably selected from the following "substituent group A" and "substituent group B" from the viewpoint of improving mechanical strength and dispersibility in olefin resins. As described above, "substituent group A" or "both of substituent group A and substituent group B" are more preferable.

(Substituent Group A)
Substituent group A is one or more substituents selected from the group consisting of a substituent represented by the following general formula (1), a substituent represented by (2) and a substituent represented by (3) is the base. These substituents are introduced into the modified cellulose singly or in any combination.
-R ¹ (1)
—CH ₂ —CH(OH)—R ² (2)
—CH ₂ —CH(OH)—CH ₂ —(OA) _n —OR ² (3)
[In the formula, R ¹ is a linear or branched hydrocarbon group having 1 to 4 carbon atoms, and each R ² is independently hydrogen or a linear or branched hydrocarbon group having 1 to 4 carbon atoms. is a hydrogen group, n is a number of 0 or more and 50 or less, and A is a linear or branched divalent hydrocarbon group having 2 or more and 3 or less carbon atoms. ]
From the viewpoint of improving heat resistance and dispersibility in olefin resins, the substituent group A is preferably a group consisting of a substituent represented by general formula (2) and a substituent represented by general formula (3). It is one or more selected, and more preferably a substituent represented by general formula (2).

R ¹ in the general formula (1) is preferably a hydrocarbon group having 2 or more carbon atoms from the viewpoint of introduction efficiency of substituents, and preferably a hydrocarbon group having 3 or less carbon atoms from the viewpoint of ensuring reactivity. is. Specific examples of R ¹ include methyl group, ethyl group, propyl group, isopropyl group, allyl group, butyl group and isobutyl group.

R ² in the general formulas (2) and (3) is preferably a hydrocarbon group having 2 or more carbon atoms from the viewpoint of efficiency of introducing a substituent, and preferably 3 or less carbon atoms from the viewpoint of ensuring reactivity. is a hydrocarbon group of Specific examples of ^R2 include methyl group, ethyl group, vinyl group, propyl group, isopropyl group, allyl group, butyl group, isobutyl group and butenyl group.

n in the general formula (3) indicates the number of moles of alkylene oxide added. n is preferably 3 or more from the viewpoint of availability and cost reduction, and preferably 40 or less from the same viewpoint.

A in the general formula (3) is a linear or branched divalent hydrocarbon group having 2 or more and 3 or less carbon atoms and forms an oxyalkylene group with an adjacent oxygen atom. The number of carbon atoms in A is preferably 2 or more from the viewpoint of availability and cost reduction. Specific examples of A are preferably an ethylene group and a propane-1,2-diyl group.

(Substituent Group B)
Substituent group B is one or more substituents selected from the group consisting of a substituent represented by the following general formula (4), a substituent represented by (5) and a substituent represented by (6) is the base. These substituents are introduced singly or in any combination.
-R ³ (4)
—CH ₂ —CH(OH)—R ³ (5)
—CH ₂ —CH(OH)—CH ₂ —(OA) _n —OR ³ (6)
[Wherein, each R ³ is independently a hydrocarbon group having a linear, branched or cyclic structure having 5 to 30 carbon atoms, n is a number of 0 to 50, and A is a carbon It is a linear or branched divalent hydrocarbon group having a number of 2 or more and 6 or less. ]
From the viewpoint of improving heat resistance and dispersibility in an olefin resin, the substituent group B is preferably a group consisting of a substituent represented by general formula (5) and a substituent represented by general formula (6). It is one or more selected, and more preferably a substituent represented by general formula (6).

The number of carbon atoms of R ³ in the general formulas (4), (5) and (6) is preferably 7 or more, more preferably 12 or more, and still more preferably 16 or more from the viewpoint of hydrophobic expression, and easy availability And from the viewpoint of ensuring reactivity, it is preferably 26 or less, more preferably 18 or less. From the viewpoint of securing availability and reactivity, R ³ is preferably a linear or branched alkyl group or alkenyl group, more preferably a linear alkyl group. Specific examples of R ³ include pentyl, hexyl, heptyl, octyl, 2-ethylhexyl, nonyl, decyl, undecyl, dodecyl, hexadecyl, octadecyl, icosyl, and triacontyl groups. saturated alkyl group, hexenyl group, heptenyl group, octenyl group, nonenyl group, decenyl group, undecenyl group, dodecenyl group, hexadecenyl group, unsaturated alkyl group such as octadecenyl group, cyclohexyl group, phenyl group, benzyl group, naphthyl group, trityl A hydrocarbon group having a cyclic structure such as a group is exemplified.

n in the general formula (6) indicates the number of moles of alkylene oxide added. From the viewpoint of availability and cost reduction, n is preferably 40 or less, more preferably 0.

A in the general formula (6) is a linear or branched divalent hydrocarbon group having 2 to 6 carbon atoms and forms an oxyalkylene group with an adjacent oxygen atom. The carbon number of A is preferably 2 or more from the viewpoint of availability and cost reduction, and preferably 4 or less from the same viewpoint.

In modified cellulose, such substituents are each independently bound to cellulose via ether linkages. Therefore, the modified cellulose in the present invention is exemplified by modified cellulose represented by the following general formula.

[In the formula, each R is independently hydrogen, Substituent Group A or Substituent Group B, and at least one R is Substituent Group A; Each substituent belonging to the substituent group A and the substituent group B may be the same or different. m is preferably an integer of 20 or more and 3,000 or less. ]

The modified cellulose represented by the general formula has a repeating structure of cellulose units into which the substituents have been introduced. As the repeating number of the repeating structure, m in the general formula is preferably 100 or more, more preferably 500 or more, from the viewpoint of improving mechanical strength, dimensional stability, and heat resistance, and from the same viewpoint, 2,000 or less. is more preferable, and 800 or less is more preferable.

(Molar degree of substitution (MS))
In the modified cellulose, the molar amount of the substituent group A introduced with respect to 1 mol of the anhydroglucose unit of the cellulose (molar substitution degree: MS) is preferably 0.5 from the viewpoint of improving the dispersibility in the olefin resin. 01 or more, more preferably 0.1 or more, and still more preferably 0.15 or more. On the other hand, from the viewpoint of improving the mechanical strength of the molded article obtained when the modified cellulose is applied to the resin composition, MS is preferably 3 or less, more preferably 1 or less, and still more preferably 0.4 or less. is. Here, when the substituent group A is composed of a plurality of types of substituents, MS is the sum of the MS of each substituent. In addition, in this specification, an anhydroglucose unit may be abbreviated as "AGU." AGU is calculated assuming that the cellulosic feedstock is composed entirely of anhydroglucose units.

In the modified cellulose, the molar amount of the substituent group B introduced with respect to 1 mol of the anhydroglucose unit of cellulose (molar substitution degree: MS) is, from the same viewpoint as the substituent group A, preferably 0.01 or more, more It is preferably 0.03 or more, more preferably 0.05 or more, preferably 3 or less, more preferably 1 or less, and still more preferably 0.1 or less. Here, when the substituent group B is composed of a plurality of types of substituents, MS is the sum of the MS of each substituent.
In this specification, the degree of introduction of substituents (that is, molar degree of substitution (MS)) can be measured according to the method described in Examples below.

(crystallinity)
Modified cellulose having a cellulose type I crystal structure is preferred as the modified cellulose.
The crystallinity of the modified cellulose is preferably 10% or more, more preferably 30% or more, and still more preferably 40% or more, from the viewpoint of strength development of the molded article to be obtained. From the viewpoint of raw material availability, it is preferably 90% or less, more preferably 70% or less, and even more preferably 60% or less. In this specification, the crystallinity of cellulose is the cellulose type I crystallinity calculated from the diffraction intensity value by the X-ray diffraction method, and can be measured according to the method described in Examples below. The cellulose type I is a crystalline form of natural cellulose, and the degree of cellulose type I crystallinity means the ratio of the amount of crystalline regions to the entire cellulose. The presence or absence of the cellulose type I crystal structure can be determined by the presence of a peak at 2θ=22.6° in the X-ray diffraction measurement described in Examples below.

[Method for producing modified cellulose]
As described above, the modified cellulose is one in which a specific substituent, preferably one or more selected from substituent group A and substituent group B, is bonded to cellulose via an ether bond. Introduction of the group can be performed according to a known method. For example, a cellulosic raw material may be reacted with a compound having a substituent (also referred to as an "etherifying agent") in the presence of a base. Here, when the substituent group A is introduced into the cellulose, the following step A is performed, and when the substituent group B is introduced into the cellulose, the following step B is performed to introduce the substituent group A and the substituent group B into the cellulose. In that case, the following step A and then step B can be performed.

(Process A)
In step A, a cellulose-based raw material and an etherifying agent are mixed and reacted in the presence of a base to introduce the substituents of the substituent group A into the cellulose of the cellulose-based raw material. The substituents belonging to Substituent Group A are introduced singly or in any combination to the hydroxy group of cellulose via an ether bond.

(cellulosic raw material)
The cellulosic raw material used in the present invention is not particularly limited, and includes woody (coniferous and broad-leaved trees), herbaceous (Poaceae, Malvaceae, and Leguminosae plant materials, non-woody materials of Palmaceae plants), and pulp. (cotton linter pulp obtained from fibers surrounding cotton seeds), papers (newspaper, cardboard, magazines, fine paper, etc.), and the like. Of these, woody plants and herbaceous plants are preferred from the viewpoint of availability and cost reduction.

Although the average fiber diameter of the cellulosic raw material is not particularly limited, it is preferably 5 μm or more, more preferably 7 μm or more, and still more preferably 15 μm or more from the viewpoint of easy availability of the cellulose raw material and cost reduction. , preferably 500 μm or less, more preferably 100 μm or less, still more preferably 30 μm or less.

Although the average fiber length of the cellulosic raw material is not particularly limited, it is preferably 1,000 μm or more, more preferably 1,500 μm or more, from the viewpoint of availability and cost reduction. It is 5,000 μm or less, more preferably 3,000 μm or less. The average fiber diameter and average fiber length of the cellulosic raw material can be measured according to the methods described in Examples below.

(base)
The base functions as a catalyst for advancing the etherification reaction or as a reaction activator for the cellulosic raw material.

The base used in this step is not particularly limited, but from the viewpoint of promoting the etherification reaction, alkali metal hydroxides, alkaline earth metal hydroxides, primary to tertiary amines, quaternary ammonium salts, imidazoles. and derivatives thereof, pyridine and derivatives thereof, and alkoxides are preferred, and one or more selected from alkali metal hydroxides are more preferred.

Alkali metal hydroxides include sodium hydroxide, potassium hydroxide, lithium hydroxide and the like.

The amount of the base cannot be unconditionally determined depending on the type of base used and the type of etherification agent, but is preferably 0.01 equivalent from the viewpoint of advancing the etherification reaction with respect to the anhydroglucose unit of the cellulosic raw material. Above, more preferably 0.1 equivalent or more, still more preferably 0.2 equivalent or more, from the viewpoint of suppressing the production cost of modified cellulose, preferably 10 equivalent or less, more preferably 1 equivalent or less, still more preferably 0.3 equivalents or less.

The cellulosic raw material and base may be mixed in the presence of a solvent. Examples of solvents include water, isopropanol, t-butanol, dimethylformamide, toluene, methyl isobutyl ketone, acetonitrile, dimethyl sulfoxide, dimethylacetamide, 1,3-dimethyl-2-imidazolidinone, hexane, 1,4-dioxane. , and mixtures thereof.

(Etherification agent)
The etherification agent is not particularly limited as long as it can introduce the substituent group A into the cellulose when reacting with the cellulosic raw material, but from the viewpoint of ensuring reactivity, a reactive cyclic A compound having a structural group and/or an organic halogen compound is preferred, a compound having a reactive cyclic structural group is more preferred, and a compound having an epoxy group is even more preferred. Compounds having substituents represented by formula (2) are described below.

As the compound having a substituent represented by general formula (2), for example, an alkylene oxide compound represented by general formula (2A) below is preferable. Such compounds may be prepared according to known techniques, or may be commercially available products. The total number of carbon atoms in the compound is 2 or more, preferably 3 or more, more preferably 4 or more from the viewpoint of efficiency of introducing substituents, and preferably 6 or less from the viewpoint of reactivity, It is more preferably 5 or less.

[In the formula, R ² is hydrogen or a linear or branched hydrocarbon group having 1 to 4 carbon atoms. ]

The number of carbon atoms and specific examples of R ² in general formula (2A) are the same as the number of carbon atoms and specific examples of R ² in general formula (2).

Specific examples of the compound represented by formula (2A) include ethylene oxide, propylene oxide, butylene oxide, 3,4-epoxy-1-butene, 1,2-epoxypentane, 1,2-epoxyhexane, 1, 2-epoxy-5-hexene is mentioned.

The amount of the etherification agent cannot be generally determined depending on the desired degree of introduction of substituents into the resulting modified cellulose and the structure of the etherification agent used. From the viewpoint of improving the mechanical strength of the molded body of the resin composition obtained in and from the viewpoint of ensuring reactivity with the cellulosic raw material, the amount of such a compound is , preferably 0.01 equivalent or more, more preferably 0.1 equivalent or more, still more preferably 1 equivalent or more. On the other hand, it is preferably 10 equivalents or less, more preferably 5 equivalents or less, and still more preferably 3 equivalents or less, from the viewpoint of suppressing the production cost of modified cellulose.

(Etherification reaction)
The etherification reaction between the etherifying agent and the cellulosic raw material can be carried out, for example, by mixing the two in the presence of a base, and the solvent may be present.

The amount of the solvent to be used is not unconditionally determined depending on the type of the cellulosic raw material and the etherifying agent, but from the viewpoint of improving the reactivity between the etherifying agent and the cellulosic raw material with respect to 100 parts by mass of the cellulosic raw material. , preferably 10 parts by mass or more, more preferably 80 parts by mass or more, still more preferably 90 parts by mass or more, and from the viewpoint of improving productivity of modified cellulose, preferably 10,000 parts by mass or less, more preferably It is 1,000 parts by mass or less, more preferably 100 parts by mass or less.

Mixing conditions are not particularly limited as long as the cellulosic raw material and the etherifying agent are uniformly mixed and the reaction can proceed sufficiently, and continuous mixing may or may not be performed. From the viewpoint of controlling the reaction temperature, stirring may be performed as appropriate.

The reaction temperature is not unconditionally determined depending on the type of cellulosic raw material and etherification agent and the target MS, but from the viewpoint of improving reactivity, it is preferably 25° C. or higher, more preferably 30° C. or higher, and still more preferably. is 40° C. or higher, and from the viewpoint of suppressing thermal decomposition, it is preferably 120° C. or lower, more preferably 70° C. or lower, and even more preferably 60° C. or lower. Moreover, a temperature rising/lowering process may be appropriately provided as necessary.

The reaction time is not unconditionally determined depending on the type of cellulosic raw material and etherification agent and the target MS, but from the viewpoint of improving the reaction rate, it is preferably 0.1 hour or more, more preferably 0.5 hour. As described above, the time is more preferably 1 hour or more, and from the viewpoint of improving productivity, the time is preferably 60 hours or less, more preferably 10 hours or less, and even more preferably 3 hours or less.

Further, after the reaction, a known pulverization treatment may be performed to pulverize the modified cellulose. Alternatively, a cellulose-based raw material that has been pulverized in advance can be used to perform the reaction for introducing a substituent as described above to obtain a pulverized modified cellulose.

After the reaction, an appropriate post-treatment can be carried out in order to remove unreacted compounds, bases and the like. As a post-treatment method, for example, an unreacted base can be neutralized with an acid (organic acid, inorganic acid, etc.), and then washed with a solvent in which the unreacted compound or base dissolves. If desired, further drying (such as vacuum drying) may be performed.

In the modified cellulose obtained by performing step A, at least one hydroxy group of cellulose has a substituent represented by the general formula (1), a substituent represented by (2), and a substituent represented by (3). It is a state in which one or more substituents selected from the group consisting of the substituents represented are ether-bonded.

(Step B)
In step B, in the presence of a base, one or more selected from the group consisting of the cellulosic raw material and the modified cellulose having substituent group A obtained in step A and an etherification agent are mixed and reacted. to introduce the substituent of the substituent group B into the cellulose or modified cellulose to obtain the modified cellulose. Substituents belonging to Substituent Group B are introduced singly or in any combination to hydroxy groups remaining in the cellulose or modified cellulose via ether bonds.

(Cellulose to be introduced with Substituent Group B)
The cellulose into which the substituent group B is to be introduced in the step B is one or more selected from the cellulosic raw material and the modified cellulose having the substituent group A obtained in the step A, preferably the cellulose obtained in the step A. It is a modified cellulose having a substituent group A.

(base)
The base used in this step is not particularly limited, and includes those listed in step A. Although the amount of the base cannot be generally determined depending on the type of the base used and the type of the etherifying agent, it is the same as the amount of the base in step A.

The mixing of cellulose and base in step B may be performed in the presence of a solvent. Examples of solvents include water, isopropanol, t-butanol, dimethylformamide, toluene, methyl isobutyl ketone, acetonitrile, dimethyl sulfoxide, dimethylacetamide, 1,3-dimethyl-2-imidazolidinone, hexane, 1,4-dioxane. , and mixtures thereof.

(Etherification agent)
The etherifying agent used in step B is not particularly limited as long as it can introduce the substituent group B into the cellulose when reacting with the cellulose. It is preferable to use a compound having a cyclic structural group and/or an organic halogen compound, more preferably a compound having a reactive cyclic structural group, and even more preferably a compound having an epoxy group. Examples of compounds having substituents represented by formula (6) are shown below.

As the compound having a substituent represented by general formula (6), for example, a glycidyl ether compound represented by general formula (6B) below is preferable. Such compounds may be prepared according to known techniques, or may be commercially available products. The total carbon number of the compound is 8 or more, preferably 11 or more, from the viewpoint of hydrophobicity, and preferably 100 or less, more preferably 75 or less, from the viewpoint of reactivity.

[In the formula, R ³ is a hydrocarbon group having 5 to 30 carbon atoms and having a linear, branched or cyclic structure, n is a number of 0 to 50, and A has 2 to 6 carbon atoms. is a straight or branched divalent hydrocarbon group. ]

The number of carbon atoms and specific examples of R ³ in general formula (6B) are the same as the number of carbon atoms and specific examples of R ³ in general formula (6).

n in the general formula (6B) indicates the number of moles of alkylene oxide added. The preferred range of the value of n is the same as the preferred range of the value of n in general formula (6).

A in the general formula (6B) is a linear or branched divalent hydrocarbon group having 2 to 6 carbon atoms and forms an oxyalkylene group with an adjacent oxygen atom. The preferred range and specific examples of the number of carbon atoms in A are the same as the preferred range and specific examples of the number of carbon atoms in A in general formula (6).

Specific examples of the compound represented by formula (6B) include 2-ethylhexyl glycidyl ether, dodecyl glycidyl ether, stearyl glycidyl ether, isostearyl glycidyl ether, polyoxyalkylene alkyl ether, 5-hexenyl glycidyl ether, 9-decyl glycidyl ether, Nyl glycidyl ether, 9-octadecenyl glycidyl ether, 17-octadecenyl glycidyl ether, phenyl glycidyl ether, trityl glycidyl ether, benzyl glycidyl ether and derivatives thereof.

The amount of the etherification agent cannot be generally determined depending on the desired degree of introduction of substituents into the resulting modified cellulose and the structure of the etherification agent used. From the viewpoint of improving the mechanical strength of the molded body of the resin composition obtained in 1 and from the viewpoint of ensuring the reactivity with cellulose, the amount of such a compound is preferably 0 with respect to 1 unit of the anhydroglucose unit of cellulose. 0.01 equivalent or more, more preferably 0.05 equivalent or more, and still more preferably 0.1 equivalent or more. On the other hand, it is preferably 10 equivalents or less, more preferably 1 equivalent or less, and even more preferably 0.5 equivalents or less, from the viewpoint of suppressing the production cost of modified cellulose.

(Etherification reaction)
The etherification reaction between the etherifying agent and cellulose can be carried out by mixing the two in the presence of a base, and the solvent may be present.

The amount of solvent to be used is not generally determined depending on the type of cellulose or etherification agent, but is preferably 10 parts by weight per 100 parts by weight of cellulose from the viewpoint of improving the reactivity between the etherification agent and cellulose. Above, more preferably 80 parts by mass or more, still more preferably 90 parts by mass or more, from the viewpoint of improving productivity of modified cellulose, preferably 10,000 parts by mass or less, more preferably 1,000 parts by mass or less and more preferably 100 parts by mass or less.

The mixing conditions are not particularly limited as long as the cellulose and the etherifying agent are uniformly mixed and the reaction can proceed sufficiently, and continuous mixing may or may not be performed. When using a relatively large reaction vessel exceeding 1 L, stirring may be performed as appropriate from the viewpoint of controlling the reaction temperature.

The reaction temperature is not unconditionally determined by the type of cellulose or etherification agent and the target degree of MS, but from the viewpoint of improving reactivity, it is preferably 25° C. or higher, more preferably 50° C. or higher, and still more preferably. is 60° C. or higher, and from the viewpoint of suppressing thermal decomposition, it is preferably 120° C. or lower, more preferably 90° C. or lower, and even more preferably 80° C. or lower. Moreover, a temperature rising/lowering process may be appropriately provided as necessary.

The reaction time is not generally determined depending on the type of cellulose or etherification agent and the target MS, but from the viewpoint of improving the reaction rate, it is preferably 1 hour or longer, more preferably 10 hours or longer, and still more preferably 20 hours. hours or more, and from the viewpoint of improving productivity, it is preferably 60 hours or less, more preferably 40 hours or less, and even more preferably 30 hours or less.

After the reaction, an appropriate post-treatment can be carried out in order to remove unreacted compounds, bases and the like. As a post-treatment method, for example, an unreacted base can be neutralized with an acid (organic acid, inorganic acid, etc.), and then washed with a solvent in which the unreacted compound or base dissolves. If desired, further drying (such as vacuum drying) may be performed.

The modified cellulose obtained by performing Step A and Step B has a substituent represented by the general formula (1), a substituent represented by (2) and ( 3) one or more substituents selected from the group consisting of the substituents represented by formula (4), and at least one hydroxy group, the substituent represented by the general formula (4), and the substituent represented by (5) It is a state in which the substituent and one or more substituents selected from the group consisting of the substituents represented by (6) are ether-bonded.

[Organic solvent]
Preferred organic solvents used in step (1) include one or more selected from N,N-dimethylformamide (DMF), xylene, toluene, dimethylsulfoxide (DMSO), chloroform, methyl ethyl ketone (MEK) and cyclohexanone. , DMF and xylene are preferred.

[Dispersion]
The dispersion in the present invention is in a state in which the modified cellulose is dispersed in the organic solvent, and one of the characteristics is that the modified cellulose is stably dispersed in the organic solvent.
The stably dispersed modified cellulose in an organic solvent means that the modified cellulose remains in the organic solvent for a long time without aggregating, for example, the change in light transmittance over time is small. A dispersion, or a dispersion in which the modified cellulose settles slowly, can be said to be a stably dispersed dispersion.

Specifically, the change in light transmittance over time of a dispersion in which modified cellulose is dispersed in an organic solvent is measured by measuring the rate of change in the light transmittance of the dispersion at a wavelength of 660 nm for 5 minutes at 25°C. More specifically, it can be obtained by measuring the rate of change calculated from the time when one minute has passed after the preparation of the dispersion, and more specifically, the following implementation Measured by the method described in the examples.

From the viewpoint of improving the elastic modulus and tensile strength of the resulting resin composition, the rate of change in light transmittance is preferably as small as possible, preferably 10% or less, more preferably 5% or less, and even more preferably 2%. It is below.

The content of the modified cellulose in the dispersion is preferably 0.01% by mass or more, more preferably 0.1% by mass or more, and still more preferably 0.5% by mass or more, from the viewpoint of removability of the organic solvent. On the other hand, from the viewpoint of improving the dispersibility of the modified cellulose in the olefin resin, the mechanical strength of the molded article, and the productivity, it is preferably 10% by mass or less, more preferably 5% by mass or less, and further Preferably, it is 3% by mass or less.

The dispersion may contain other components as long as they do not inhibit the effects of the present invention.

[Method for preparing dispersion]
The dispersion can be prepared by subjecting the modified cellulose and the organic solvent used in the step (1), optionally together with other components, to a dispersion treatment using a high-pressure homogenizer.

[Olefin resin]
Olefin resins include ethylene polymers [high-density polyethylene, medium-density polyethylene, low-density polyethylene, ethylene and one or more other vinyl compounds (e.g., α-olefin, vinyl acetate, methacrylic acid, acrylic acid, etc.). copolymers, etc.], propylene-based polymers [polypropylene, copolymers of propylene and one or more other vinyl compounds, etc.], ethylene-propylene copolymers, polybutene and poly-4-methylpentene-1, etc. are exemplified.

The molecular weight of the olefinic resin is not particularly limited, but preferably those having a weight average molecular weight of 5000 to 500,000 can be used.

The olefin resin preferably has a melt flow rate (MFR) of 2 g/10 min or more, more preferably 4 g/10 min or more, and still more preferably 5 g/10 min or more, from the viewpoint of ease of molding. On the other hand, from the same viewpoint, it is preferably 50 g/10 min or less, more preferably 30 g/10 min or less, and even more preferably 15 g/10 min or less. In this specification, the MFR is measured by the method described in Examples below.

The melting point of the olefin resin is preferably 120° C. or higher, more preferably 125° C. or higher, from the viewpoint of ease of molding, and is preferably 170° C. or lower, more preferably 165° C. from the same viewpoint. ℃ or less.

[Compatibilizer]
In step (1), a compatibilizer can be further added. By using a compatibilizer, the interface between the olefin resin and the modified cellulose is strengthened, and the dispersibility of the modified cellulose in the olefin resin is improved. can be expected to improve.

As the compatibilizer, 1 selected from the group consisting of (A) a compound having an acid anhydride group, (B) a compound having an epoxy group, (C) a compound having an isocyanate group, and (D) a silane coupling agent species, or those containing two or more species.

The acid anhydride group in the compound (A) is not particularly limited, and examples thereof include those derived from maleic anhydride, succinic anhydride, glutaric anhydride and the like.

Examples of compounds in the compound (A) include polyolefin-based, acrylic, and styrene-based polymer compounds, and polyolefin-based polymer compounds are preferred from the viewpoint of affinity with the resin to be blended.

Examples of polyolefin-based polymers include ethylene-based polymers [high-density polyethylene, medium-density polyethylene, low-density polyethylene, ethylene and one or more other vinyl compounds (e.g., α-olefin, vinyl acetate, methacrylic acid, acrylic acid, etc.). )], propylene polymers [polypropylene, copolymers of propylene and one or more other vinyl compounds, etc.], ethylene propylene copolymers, polybutene and poly-4-methylpentene-1 etc. are exemplified, but propylene-based polymers are preferred.

Specific examples of the (A) compound include, for example, maleic anhydride-modified polyolefin, and more specifically, maleic anhydride-modified polypropylene.

(A) compound may be prepared according to a known method, or a commercially available product may be used. Suitable commercially available products include, for example, "Umex" manufactured by Sanyo Chemical Industries (polypropylene having a maleic anhydride group), "OREVAC G" manufactured by Arkema (polypropylene having a maleic anhydride group), " Bondine" (ethylene/acrylic acid/maleic anhydride terpolymer) and the like are exemplified.

The weight average molecular weight (Mw) of the compound (A) is preferably 1,000 or more, more preferably 5,000 or more, still more preferably 10,000 or more, from the viewpoint of affinity with the modified cellulose. In addition, from the viewpoint of manifestation of physical properties due to entanglement with the polypropylene resin, it is preferably 150,000 or less, more preferably 140,000 or less, and even more preferably 100,000 or less.

In addition, the compound (A) has a melting point of preferably 250° C. or less, more preferably 200° C. or less, and still more preferably 150° C. or less from the viewpoint of suppressing deterioration of the modified cellulose when composited with a resin. preferable. The lower limit is not particularly limited, and is about 100° C., for example.

From the viewpoint of improving the elastic modulus and strength of the resin composition, the amount of the compatibilizer compounded in step (1) is preferably 0.1 parts by mass or more, more preferably It is 1 part by mass or more, more preferably 5 parts by mass or more, and from the same viewpoint, preferably 10 parts by mass or less, more preferably 8 parts by mass or less, and even more preferably 6 parts by mass or less.

The amount of the compatibilizer compounded in step (1) is preferably 1 part by mass or more, more preferably 5 parts by mass or more, and still more preferably It is 10 parts by mass or more, more preferably 30 parts by mass or more. On the other hand, from the viewpoint of cost effectiveness, the amount of the compatibilizing agent in the resin composition is preferably 50 parts by mass or less, more preferably 40 parts by mass or less, and still more preferably 35 parts by mass with respect to 100 parts by mass of the modified cellulose. It is below the department.

The mixture may contain other components as long as they do not inhibit the effects of the present invention.

[Method for preparing mixture]
In step (1), a mixture can be prepared by subjecting the dispersion liquid and the olefin-based resin in a predetermined ratio, together with other components as necessary, to dispersion treatment, for example, with a homogenizer. . The time, temperature, etc. of the dispersion treatment are not particularly limited, and may be carried out at around room temperature.

In step (1), the mixing ratio of the dispersion liquid and the olefin resin is preferably 0.1 mass of the olefin resin with respect to 100 mass of the dispersion liquid from the viewpoint of volatilizing the organic solvent. part or more, more preferably 1 part by mass or more, and still more preferably 2 parts by mass or more. On the other hand, from the viewpoint of improving the dispersibility of the modified cellulose in the olefin resin, the The olefinic resin is preferably 100 parts by mass or less, more preferably 20 parts by mass or less, and even more preferably 15 parts by mass or less.

From the viewpoint of improving productivity, the content of the modified cellulose in the mixture of the dispersion and the olefin resin is preferably 0.01% by mass or more, more preferably 0.1% by mass or more, and further It is preferably 0.5% by mass or more, and on the other hand, from the viewpoint of improving the dispersibility of the modified cellulose in the olefin resin, it is preferably 10% by mass or less, more preferably 5% by mass or less, and still more preferably 1% by mass. % by mass or less.

[Step (2)]
In step (2), the step of kneading the mixture obtained in step (1) (step (2-1)) and the step of removing the organic solvent from the mixture obtained in step (1) (step (2-2 )) is performed. In the present invention, step (2-1) and step (2-2) may be performed simultaneously, step (2-2) may be performed after step (2-1), or step (2 -2) may be followed by step (2-1).

[Step (2-1)]
In step (2-1), the mixture obtained in step (1) is kneaded.
The temperature (Tm (° C.)) of the mixture during kneading is not particularly limited, but kneading at a temperature that satisfies the following formula (1) allows steps (2-1) and (2-2) to be performed simultaneously. Therefore, it is preferable.
Tm-80°C≤Tbp≤Tm+50°C
(In the formula, Tbp is the boiling point of the organic solvent that constitutes the dispersion.)

More specifically, from the viewpoint of improving the removal rate of the organic solvent, Tm is preferably 100° C. or higher, more preferably 130° C. or higher, and still more preferably 150° C. or higher. From the viewpoint of suppressing deterioration, Tm is preferably 250° C. or lower, more preferably 200° C. or lower, and even more preferably 160° C. or lower.

Regarding the lower limit of Tbp, and from the viewpoint of suppressing aggregation of the modified cellulose, it is preferably Tm-70°C, more preferably Tm-30°C, and still more preferably Tm-20°C. On the other hand, the upper limit of Tbp is preferably Tm+30°C, more preferably Tm+20°C, still more preferably Tm+10°C, from the viewpoint of improving the removal rate of the organic solvent.

The time for which the mixture is subjected to the operation in step (2-1) is not particularly limited, but it is possible to improve the removal rate of the organic solvent, suppress the aggregation of the modified cellulose, and improve the dispersibility of the modified cellulose in the olefin resin. From the point of view, it is preferably 3 seconds or longer, more preferably 10 seconds or longer, still more preferably 100 seconds or longer, and still more preferably 150 seconds or longer. It is 600 seconds or less, more preferably 400 seconds or less, still more preferably 200 seconds or less.

[Step (2-2)]
In step (2-2), the organic solvent is removed from the mixture obtained in step (1). For example, it is preferable to volatilize and remove the organic solvent by heating and/or placing the mixture under reduced pressure.

Specifically, it is preferable to heat the mixture so that the temperature (Tm (° C.)) of the mixture during kneading satisfies the above formula (1). For example, the temperature of the mixture during kneading can be easily set to a desired temperature by adjusting the temperature of the processing equipment for performing this step.

The absolute pressure in step (2-2) is preferably 0.11 MPa or less, more preferably 0.05 MPa or less, and still more preferably 0.01 MPa or less, from the viewpoint of the residual organic solvent and the removal rate. On the other hand, from the viewpoint of simplification of equipment for carrying out step (2) and productivity, it is preferable to place the mixture under atmospheric pressure.

In step (2-2), it is more preferable to satisfy both the preferred ranges of temperature and pressure.

The time for which the mixture is subjected to the operation in step (2-2) is not particularly limited, but it is possible to improve the removal rate of the organic solvent, suppress the aggregation of the modified cellulose, and improve the dispersibility of the modified cellulose in the olefin resin. From the point of view, it is preferably 3 seconds or more, more preferably 5 seconds or more, and still more preferably 10 seconds or more. It is preferably 400 seconds or less, more preferably 200 seconds or less.

Processing equipment for carrying out step (2) includes twin-screw extruders, single-screw extruders, internal kneaders, open-roll type kneaders, and dryers. In particular, by using a kneading device capable of kneading the mixture under reduced pressure and/or under heat, for example, a kneading device with an open vent port or a vacuum vent device, step (2-1) and step (2- 2) can be performed simultaneously.

<Resin composition>
A resin composition can be produced through the above steps (1) and (2). Such resin compositions are characterized by high mechanical strength, such as tensile modulus and/or tensile strength, of moldings obtained by molding them.

Although the amount of each component in the resin composition depends on the type of resin, it is as follows.
The amount of the olefin resin in the resin composition is preferably 50% by mass or more, more preferably 60% by mass or more, and still more preferably 70% by mass or more, from the viewpoint of facilitating the production of molded articles. From the viewpoint of increasing the amount of cellulose blended and improving the elastic modulus and strength of the resulting resin composition, it is preferably 99.5% by mass or less, more preferably 99% by mass or less, even more preferably 98% by mass or less, and further Preferably, it is 95% by mass or less.

The amount of modified cellulose in the resin composition is preferably 0.5% by mass or more, more preferably 5% by mass or more, and still more preferably 10% by mass, from the viewpoint of improving the elastic modulus and strength of the resulting resin composition. % by mass or more, more preferably 20% by mass or more, and from the viewpoint of improving the strength of the resulting resin composition, preferably 70% by mass or less, more preferably 60% by mass or less, and even more preferably 50% by mass or less, It is more preferably 40% by mass or less, still more preferably 30% by mass or less.

In addition, the amount of the modified cellulose in the resin composition is preferably 1 part by mass or more, more preferably 1 part by mass or more, based on 100 parts by mass of the olefin resin, from the viewpoint of improving the elastic modulus and strength of the resulting resin composition. is 10 parts by mass or more, more preferably 15 parts by mass or more, and from the viewpoint of the strength of the resulting resin composition, preferably 200 parts by mass or less, more preferably 100 parts by mass or less, and even more preferably 70 parts by mass. 50 parts by mass or less, more preferably 50 parts by mass or less.

The resin composition contains, as components other than the above, a plasticizer; a crystal nucleating agent; a filler (inorganic filler, organic filler); a hydrolysis inhibitor; a flame retardant; Lubricants that are anionic surfactants; ultraviolet absorbers; antistatic agents; antifog agents; light stabilizers; pigments; Natural proteins such as gelatin, glue, and casein; inorganic compounds such as tannin, zeolite, ceramics, and metal powders; fragrances; flow control agents; leveling agents; It can be blended within a range that does not impair the effect. Similarly, other polymer materials and other resin compositions can be blended within a range that does not impair the effects of the present invention. The blending ratio of such optional components is, for example, preferably 20% by mass or less, more preferably 10% by mass or less, and even more preferably 5% by mass or less in the resin composition.

<Resin molding>
The resin molded article (molded article) of the present invention can be produced by molding the resin composition produced by the production method of the present invention by a known method. Such molded articles can be suitably used as resin molding materials and electrical insulating materials in the fields of electronics, aerospace, civil engineering and construction, automobiles, vehicle applications, and the like.

EXAMPLES The present invention will be specifically described below with reference to Production Examples, Examples, Comparative Examples and Test Examples. These examples and the like are merely illustrations of the present invention, and do not mean any limitation. Parts in the examples are parts by weight unless otherwise specified. In addition, "atmospheric pressure" indicates 101.3 kPa, and "room temperature" indicates 25°C.

[Solid content in dispersion]
A halogen moisture meter (manufactured by Shimadzu Corporation, trade name: MOC-120H) is used. 1 g of the sample is measured at a constant temperature of 150° C. every 30 seconds, and the value at which the mass reduction rate becomes 0.1% or less is defined as the solid content.

[Degree of Introduction of Substituents]
First, the content % (% by mass) of the substituent contained in the modified cellulose to be measured is determined according to Analytical Chemistry, Vol.51, No.13, 2172 (1979), "Japanese Pharmacopoeia 15th Edition (Section of analytical method of hydroxypropyl cellulose)", etc., was calculated according to the Zeisel method known as a technique for analyzing the average number of added moles of alkoxy groups of cellulose ether. The procedure is shown below.

(i) 0.1 g of n-tetradecane was added to a 200 mL volumetric flask, and the volume was increased to the marked line with hexane to prepare an internal standard solution.
(ii) 70 mg of the purified and dried modified cellulose and 80 mg of adipic acid to be measured were accurately weighed into a 10 mL vial, 2 mL of hydroiodic acid was added, and the vial was sealed.
(iii) The mixture in the vial was heated with a block heater at 160° C. for 1 hour while stirring with a stirrer tip.
(iv) After heating, 2 mL of the internal standard solution and 2 mL of diethyl ether were sequentially injected into the vial and stirred at room temperature for 1 minute.
(v) The upper layer (diethyl ether layer) of the mixture separated into two layers in the vial was analyzed by gas chromatography (manufactured by SHIMADZU, trade name: GC2010Plus).
(vi) Analyze in the same manner as (ii) to (v) except that the modified cellulose to be measured is changed to 5 mg, 10 mg, and 15 mg of the etherification agent used for the modification, and etherification A calibration curve for the agent was prepared.
(vii) Substituents contained in the modified cellulose to be measured were quantified from the prepared calibration curve and the analytical results of the modified cellulose to be measured. Analysis conditions are as follows.

Column: manufactured by Agilent Technologies, trade name: DB-5 (12 m, 0.2 mm × 0.33 μm)
Column temperature: 30°C (10min Hold) → 10°C/min → 300°C (10min Hold)
Injector temperature: 300°C
Detector temperature: 300°C
Injection amount: 1 μL

The content (% by mass) of the substituent contained in the modified cellulose to be measured was calculated from the detected amount of the etherifying agent used.
Next, from the obtained content of substituents, the molar substitution degree (MS) (molar amount of substituents per 1 mol of anhydroglucose unit) was calculated using the following formula (1). Here, the MS for the substituent group A is defined as MS _A , and the MS for the substituent group B is defined as MS _B.
Formula (1)
MS _A = (W _A /Mw _A )/((100−W _A −W _B )/162.14)
MS _B =(W _B /Mw _B )/((100−W _A −W _B )/162.14)
W _A : content of substituent group A in modified cellulose to be measured (% by mass)
W _B : content of substituent group B in modified cellulose to be measured (% by mass)
Mw _A : Molecular weight (g/mol) of the etherifying agent for introducing the substituent group A
Mw _B : Molecular weight (g/mol) of etherifying agent for introduction of Substituent Group B

[Measurement of average fiber diameter of cellulosic raw material]
Deionized water was added to the object to be measured to prepare a dispersion having a content of 0.01% by mass. Using a wet dispersion type image analysis particle size distribution meter (manufactured by Jusco International Co., Ltd., trade name: IF-3200), the dispersion is measured with a front lens of 2x, a telecentric zoom lens of 1x, and an image resolution of 0.835 μm/pixel. , syringe inner diameter: 6515 μm, spacer thickness: 500 μm, image recognition mode: ghost, threshold: 8, analysis sample amount: 1 mL, sampling: 15%. 100 or more measurement objects were measured, and their average ISO fiber diameter was calculated as the average fiber diameter.

[Determination of presence/absence of diffraction peak at 2θ=13-23°]
The presence or absence of the diffraction peak at 2θ=13-23° of the modified cellulose in the present specification is determined using a diffractometer (trade name: RigakuRINT 2500VC X-RAY diffractometer manufactured by Rigaku Corporation) under the following conditions. It was determined by

Measurement pellet preparation conditions: Smooth pellets with an area of 320 mm ² × thickness of 1 mm were prepared by applying pressure in the range of 10 to 20 MPa with a tableting machine.
X-ray diffraction analysis conditions: step angle 0.01°, scan speed 10°/min, measurement range: diffraction angle 2θ = 5 to 45°
X-ray source: Cu/Kα-radiation, tube voltage: 40 kv, tube current: 120 mA
Peak splitting conditions: After removing background noise, fitting was performed with a Gaussian function so that the error between 2θ=13-23° was within 5%.

[Confirmation of crystal structure]
The crystal structure of the modified cellulose was confirmed by measurement under the above conditions using the above diffractometer.
The crystallinity of the cellulose type I crystal structure was calculated based on the following formula (A) using the areas of the X-ray diffraction peaks obtained by the above peak division.
Cellulose type I crystallinity (%) = [I _cr / (I _cr + I _am )] × 100 (A)
[Wherein, I _cr is the area of the diffraction peak of the lattice plane (002 plane) (diffraction angle 2θ=22-23°) in X-ray diffraction, and I _am is the amorphous part (diffraction angle 2θ=18.5°). Areas of diffraction peaks are shown. ]

[Melt flow rate]
Melt flow rate (g/10 min) was measured under conditions of 230°C and 2.16 kgf according to the method described in JIS K7210.

Production Example 1 <Addition of Butylene Oxide>
Bleached coniferous kraft pulp (hereinafter abbreviated as NBKP, manufactured by West Fraser, trade name: Hinton, fibrous, average fiber diameter 24 μm, cellulose content 90% by mass, moisture content 5% by mass) as a cellulose-based raw material Using. First, 1.5 g of a 6.4% by mass sodium hydroxide aqueous solution (0.26 equivalent of NaOH/AGU) was added to 1.5 g of absolutely dried NBKP and uniformly mixed. After that, 1.50 g (2.25 equivalents/AGU) of butylene oxide was added as an etherification agent, and after sealing, the reaction was allowed to stand at 50° C. for 2 hours. After completion of the reaction, neutralize with acetic acid, thoroughly wash with water and acetone to remove impurities, and vacuum-dry overnight at 70° C. to obtain modified cellulose 1 (MS of butylene oxide: 0.31). got

Production Example 2 <Dodecyl glycidyl ether addition>
To 1.5 g of the modified cellulose 1, 1.5 g of a 6.4% by mass sodium hydroxide aqueous solution (0.27 equivalent of NaOH/AGU) was added and uniformly mixed. After that, 0.42 g (0.2 equivalent/AGU) of dodecyl glycidyl ether was added as an etherifying agent, and after sealing, the reaction was allowed to stand at 70° C. for 24 hours. After completion of the reaction, neutralization, washing and vacuum drying were carried out in the same manner as in Production Example 1 to obtain modified cellulose 2 (MS of dodecyl glycidyl ether: 0.08).

Production Example 3 <Stearyl glycidyl ether addition>
To 1.5 g of absolutely dried NBKP, 1.5 g of 6.4% by mass sodium hydroxide aqueous solution (0.26 equivalent of NaOH/AGU) was added and mixed uniformly. After that, 1.00 g (1.50 equivalents/AGU) of butylene oxide was added as an etherification agent, and after sealing, the reaction was allowed to stand at 50° C. for 2 hours. After completion of the reaction, it was neutralized with acetic acid, thoroughly washed with water and acetone to remove impurities, and vacuum-dried overnight at 70° C. to obtain modified cellulose 1′ (MS of butylene oxide: 0.19). ).

To 1.5 g of the modified cellulose 1', 1.5 g of a 6.4% by mass sodium hydroxide aqueous solution (0.27 equivalent of NaOH/AGU) was added and uniformly mixed. Then, 0.29 g (0.1 equivalent/AGU) of stearyl glycidyl ether was added as an etherifying agent, and after sealing, the reaction was allowed to stand at 70° C. for 24 hours. After the reaction, neutralization, washing and vacuum drying were carried out in the same manner as in Production Example 1 to obtain modified cellulose 3 (MS of stearyl glycidyl ether: 0.05).

Table 1 shows a summary of the production examples. BO is an abbreviation for butylene oxide, LGE is an abbreviation for dodecyl glycidyl ether, and SGE is an abbreviation for stearyl glycidyl ether.

Example 1 <Production of resin composition>
[Preparation of dispersion]
0.500 g of the modified cellulose 1 was put into 49.5 g of DMF as an organic solvent, and the mixture was stirred at 3000 rpm for 30 minutes with a homogenizer (TK Robomix, manufactured by Primix). After that, a modified cellulose dispersion liquid (solid content: 1.0 % by mass) was prepared.

[Preparation of mixture: step (1)]
1500 parts of the dispersion liquid and 85.0 parts of the polypropylene resin were charged into a homogenizer (TK Robomix manufactured by Primix) and stirred at 500 rpm for 3 minutes to obtain a mixture.

[Kneading the mixture and removing the organic solvent: step (2)]
The obtained mixture was kneaded and the organic solvent was removed using a three-roll mill (manufactured by Inoue Seisakusho Co., Ltd., diameter 12.5 cm).
Specifically, the roll surface, that is, the temperature (Tm) of the mixture is set to 155 ° C., the first roll is set to 10 rpm, the second roll is set to 30 rpm, and the third roll is set to 90 rpm. The mixture was put between the second roll and stripped from the third roll to obtain the product. The obtained product was kneaded and the organic solvent was removed twice under the same conditions to produce a resin composition. In this operation, kneading (step (2-1) and removing the organic solvent (step (2-2)) were performed almost simultaneously.

Examples 2 to 8 <Production of resin composition>
[Preparation of dispersion]
Each modified cellulose dispersion (solid content: 1.0% by mass) was prepared in the same manner as in Example 1 using the modified cellulose and organic solvent of the types and amounts shown in Table 2. bottom.

[Preparation of mixture: step (1)]
The types and amounts of the dispersions, polypropylene resins and compatibilizers of each example shown in Table 2 are put into a homogenizer ("TK Robomix" manufactured by Primix) and stirred at 500 rpm for 3 minutes. , to obtain a mixture of each example.

[Kneading the mixture and removing the organic solvent: step (2)]
The obtained mixture of each example was kneaded and the organic solvent was removed under the same conditions as in Example 1 to produce a resin composition of each example.

Comparative Example 1 <Production of resin composition>
For comparison, polypropylene resin itself was used as a resin composition.

Comparative Examples 2 and 3 <Production of resin composition>
For comparison, a resin composition was produced using only modified cellulose and polypropylene resin without using an organic solvent.
Specifically, the modified cellulose 1 or 2 and the polypropylene resin in the amounts shown in Table 2 are put into a Henschel mixer (manufactured by Mitsui Miike Kakoki Co., Ltd., capacity 20 L) and stirred at 1000 rpm for 1 minute to obtain a mixture. rice field. Subsequently, the obtained mixture was subjected to the same operation as in the step (2) of Example 1 to produce a resin composition.

Comparative Example 4 <Production of resin composition>
For comparison, a resin composition was produced using water instead of the organic solvent as a solvent constituting the dispersion. Specifically, a resin composition was produced as follows.
A modified cellulose dispersion (solid content: 1.0% by mass) was prepared in the same manner as in Example 1, except that water was used instead of DMF and modified cellulose 2 was used as the modified cellulose. ) was prepared. Next, the obtained dispersion was stirred under the same conditions as in Example 1 to obtain a mixture, and the obtained mixture was subjected to the same operation as in step (2) of Example 1 to produce a resin composition.

Test Example 1 (tensile modulus and tensile strength)
3 g of each resin composition thus obtained was sandwiched between a spacer of 200 mm×200 mm×0.4 mm and an iron ferroplate, and a press sheet was produced using an auto press ("precision molding" manufactured by Toyo Seiki Seisakusho). Specifically, it was pressed at 185° C./0.5 MPa for 2 minutes, and then pressed at 185° C./20 MPa for 1 minute. Further, it was pressed at 80° C./10 MPa for 1 minute to obtain a sheet with a thickness of 0.3 to 0.4 mm.

In a constant temperature room at 23 ° C., a dumbbell-shaped test piece of JIS K6251 (vulcanized rubber and thermoplastic rubber-determination of tensile properties) dumbbell-shaped test piece No. 7 was prepared using each sheet, and tensile did the test. For the tensile test, an autograph precision universal testing machine ("AGS-10kNX" manufactured by SHIMADZU) was used, and the thickness was measured using the average value of 3 points at the test points, the distance between the marked lines was 10 mm, the test speed was 50 mm / min, Tensile modulus and tensile strength were obtained by performing five tests per sample and averaging them.

Test Example 2 (dispersibility of dispersion liquid)
The dispersibility of the dispersion prepared in each example and comparative example 4 was evaluated as follows. In addition, the measurement of the light transmittance was carried out under the environment of 25° C. and atmospheric pressure.

30 mL of the resulting dispersion was transferred to a screw tube (No. 7 manufactured by AS ONE), the dispersion was shaken together with the screw tube, and 3 mL of the visually uniform sample was placed in a quartz cell having an optical path length of 10 mm. The screw tube was left as it was. After allowing the cell to stand still for 1 minute, absorbance at a wavelength of 660 nm was measured using a double beam spectrophotometer ("U-2910" manufactured by Hitachi High-Tech Science Co., Ltd.). The light transmittance was calculated using purified water as a blank to obtain the initial light transmittance (T ₀ ).

For the screw tube containing the dispersion, after standing still for 5 minutes, the dispersion was sampled from within 20% of the upper part of the liquid surface. The absorbance at a wavelength of 660 nm was measured in the same manner as in , and the light transmittance (T ₅ ) after 5 minutes was obtained.
Next, the rate of change (%) of the light transmittance of the dispersion liquid at a wavelength of 660 nm for 5 minutes was obtained from the following equation.
Rate of change (%) = 100 × (T ₅ - T ₀ )/T ₀

A dispersion with good dispersion stability has a small amount of modified cellulose that settles after standing still for 5 minutes, so the value of T ₅ −T ₀ is small and the rate of change (%) is also small (experimental error from the point of view, if the value of T ₅ -T ₀ is negative, treat the value of T ₅ -T ₀ as zero). On the other hand, a dispersion with poor dispersion stability has a large amount of modified cellulose that settles after standing still for 5 minutes, and therefore has a large T ₅ -T ₀ value and a large rate of change (%).

Each condition and result are shown in Table 2.

The details of each component used in the above production examples are as follows.
PP: polypropylene resin, manufactured by Prime Polymer, trade name: J105P, MFR: 10 g/10 min (230°C, 2.16 kgf)
Xylene: o-xylene, manufactured by Fujifilm Wako Pure Chemical Industries, boiling point 144°C
DMF: manufactured by Fujifilm Wako Pure Chemical, boiling point 153°C
Yumex 1001: manufactured by Sanyo Chemical Industries, Ltd., maleic anhydride-modified polypropylene, mass average molecular weight 45,000

From the above experimental results, the molded articles of the resin compositions produced by the production methods of Examples were excellent in tensile modulus and tensile strength. On the other hand, looking at the rate of change of the dispersion liquid in each example, it was found that the modified cellulose in the dispersion liquid was stably dispersed. Considering these facts, the modified cellulose is stably dispersed in the dispersion liquid, so that the dispersibility of the modified cellulose in the olefinic resin becomes high. It was suggested that the mechanical strength of the body was improved.

On the other hand, Comparative Example 1, which did not use the modified cellulose and the organic solvent, had a poor tensile modulus. Furthermore, Comparative Examples 2 and 3, in which no organic solvent was used, exhibited poor tensile strength, and Comparative Example 4, in which water was used as a solvent, exhibited poor tensile modulus and tensile strength. Comparing Example 5 and Comparative Example 3, it was confirmed that Example 5 had an effect equal to or greater than that of Comparative Example 3, although the amount of modified cellulose was half that of Example 5. In Comparative Examples 2 and 3, it is suggested that the modified cellulose was insufficiently dispersed because no organic solvent was used. Furthermore, in Comparative Example 4, it was suggested that the modified cellulose was insufficiently dispersed because the solvent was used although water was used. It is backed up by what happened.

Molded articles obtained by molding the resin composition of the present invention can be suitably used as resin molding materials and electrical insulating materials in the fields of electronics, aerospace, civil engineering and construction, automobiles, vehicle applications, and the like. .

Claims (7)

A method for producing a resin composition, comprising the following steps (1) and (2).
Step (1): A modified cellulose in which one or more substituents selected from the group consisting of Substituent Group A and Substituent Group B below are each independently bound via an ether bond is dispersed in an organic solvent. Step ( 2 ): Step of kneading the mixture obtained in step (1) and removing the organic solvent from the mixture
(Here, the substituent group A is one or more substituents selected from the group consisting of substituents represented by the following general formula (2) and substituents represented by the general formula (3),
—CH ₂ —CH(OH)—R ² (2)
—CH ₂ —CH(OH)—CH ₂ —(OA) _n —OR ² (3)
[In the formula, each R ² is independently hydrogen or a straight or branched chain hydrocarbon group having 1 to 4 carbon atoms, n is a number of 0 to 50, and A has 2 or more carbon atoms. A linear or branched divalent hydrocarbon group of 3 or less. ]
Substituent group B is one or more substituents selected from the group consisting of substituents represented by the following general formula (5) and substituents represented by general formula (6).
—CH ₂ —CH(OH)—R ³ (5)
—CH ₂ —CH(OH)—CH ₂ —(OA) _n —OR ³ (6)
[Wherein, each R ³ is independently a hydrocarbon group having a linear, branched or cyclic structure having 5 to 30 carbon atoms, n is a number of 0 to 50, and A is a carbon It is a linear or branched divalent hydrocarbon group having a number of 2 or more and 6 or less. ]) 2. The method for producing a resin composition according to claim 1, wherein the kneading temperature (Tm (°C)) of the mixture obtained in step (1) in step (2) satisfies the following formula (1).
Tm-80°C≤Tbp≤Tm+50°C
(In the formula, Tbp is the boiling point of the organic solvent that constitutes the dispersion.) 3. The method for producing a resin composition according to claim 1, wherein a rate of change in transmittance of said dispersion at a wavelength of 660 nm for 5 minutes at 25[deg.] C. is 10% or less. The method for producing a resin composition according to any one of claims 1 to 3, wherein the content of the modified cellulose in the dispersion is 0.01% by mass or more and 10% by mass or less. The resin composition according to any one of claims 1 to 4, wherein in the step (1), 0.1 parts by mass or more and 100 parts by mass or less of the olefin resin is mixed with 100 parts by mass of the dispersion liquid. A method of making things. In the step (2), the step of kneading the mixture obtained in step (1) (step (2-1)) and the step of removing the organic solvent from the mixture obtained in step (1) (step (2- 2)) is performed, the method for producing a resin composition according to any one of claims 1 to 5. The organic solvent used in step (1) is one or more selected from the group consisting of N,N-dimethylformamide (DMF), xylene, toluene, dimethylsulfoxide (DMSO), chloroform, methyl ethyl ketone (MEK) and cyclohexanone. The method for producing a resin composition according to any one of claims 1 to 6.