JP2020196878A - Resin composition - Google Patents

Abstract

To provide a resin composition that effectively suppresses coloring degradation and contains engineering plastic and modified cellulose fiber.SOLUTION: A resin composition contains engineering plastic and modified cellulose fiber. The modified cellulose fiber has cellulose I-type crystal. To at least one of cellulose-derived hydroxy groups, a substituent having an aromatic ring is bound via ether linkage.SELECTED DRAWING: None

Description

The present invention relates to resin compositions containing engineering plastics.

Conventionally, engineering plastics such as polyamide, polycarbonate, and polyacetal have been replaced with engineering plastics for the purpose of reducing the weight of metal materials. However, its range of use has been limited due to problems such as dimensional stability and deterioration of mechanical properties at high temperatures. In order to solve these problems, inorganic fillers such as glass fiber are generally used together, but it is difficult to recycle materials and thermals for resins containing inorganic fillers, and the current situation is that they have to be filled at the time of disposal. .. In recent years, a technique using cellulose fibers as an environment-friendly organic filler instead of an inorganic filler has attracted attention, but in general, color deterioration in the molding process of engineering plastics exceeding 250 ° C. becomes a big problem.

For example, Patent Document 1 discloses cellulose fine fibers in which an acetyl group is introduced at the same time as or after defibration of cellulose in order to impart heat resistance.

JP-A-2019-6875

However, as a result of studies by the present inventors, since the cellulose fiber of Patent Document 1 has a chemically unstable ester bond, it is sufficient to suppress color deterioration of the molded product produced by combining with the resin. I was not satisfied with it.

Therefore, the present invention relates to a resin composition containing engineering plastics and modified cellulose fibers, which is excellent in suppressing color deterioration, and a method for producing the same.

The present invention relates to the following [1] to [2].
[1] A resin composition containing engineering plastics and modified cellulose fibers.
A resin composition in which the modified cellulose fiber has a cellulose type I crystal, and a substituent having an aromatic ring at at least one of the hydroxyl groups derived from cellulose is bonded via an ether bond.
[2] A method for producing a resin composition, which comprises a mixing step of mixing engineering plastics and modified cellulose fibers.
A method for producing a resin composition, wherein the modified cellulose fiber has a cellulose type I crystal, and a substituent having an aromatic ring at at least one of the hydroxyl groups derived from cellulose is bonded via an ether bond. ..

The molded product obtained by using the resin composition of the present invention has an excellent effect of suppressing color deterioration, and according to the production method of the present invention, a resin composition having such an effect can be produced.

<Resin composition>
The resin composition of the present invention is a resin composition containing an engineering plastic and a modified cellulose fiber having a specific substituent.

[Engineering plastic]
In the present invention, any engineering plastic can be used without particular limitation. The engineering plastic may be a crystalline resin or an amorphous resin.

In the case of a crystalline resin, the thermal deformation temperature is preferably 100 ° C. or higher, more preferably 110 ° C. or higher, still more preferably 120 ° C. or higher, from the viewpoint of exhibiting the effect of suppressing color deterioration. The method for measuring the thermal deformation temperature of the crystalline resin is as described in Examples described later.

In the case of an amorphous resin, the higher the glass transition temperature is, the more preferable it is, from the viewpoint of exhibiting the effect of suppressing color deterioration, specifically, preferably 100 ° C. or higher, more preferably 110 ° C. or higher, still more preferably 120 ° C. or higher. Is. The method for measuring the glass transition temperature is as described in Examples described later.

Whether it is a crystalline resin or an amorphous resin, from the viewpoint of using it as an engineering plastic, the higher the tensile strength at 25 ° C. is, the more preferable, specifically, 49 MPa or more, more preferably. It is 55 MPa or more, more preferably 60 MPa or more. The method for measuring the tensile strength is as described in Examples described later.

Regardless of whether it is a crystalline resin or an amorphous resin, the higher the flexural modulus at 25 ° C. is, the more preferable it is, and more specifically, 2 GPa or more is more preferable, from the viewpoint of exhibiting the coloring suppressing effect. Is 2.2 GPa or more, more preferably 2.5 GPa or more. The method for measuring the flexural modulus is as described in Examples described later.

Specific examples of engineering plastics used in the present invention include polyamide, polybutylene terephthalate, polypropylene terephthalate, polyethylene terephthalate, polycarbonate, polyacetal, modified polyphenylene oxide, modified polyphenylene ether, polyphenylene sulfide, polyetheretherketone, polyethersulfone, and polysulfone. , Polyamideimide, polyetherimide, polyimide, polyallylate, polyarylethernitrile and the like. The crystallinity cannot be unconditionally determined depending on the application and the chemical structure of the resin, but the crystalline resins in these examples include polyamide, polybutylene terephthalate, polypropylene terephthalate, polyethylene terephthalate, polyacetal, polyphenylene sulfide, and polyetheretherketone. Polyallyl ether nitrile is exemplified, and examples of the amorphous resin include polycarbonate, modified polyphenylene oxide, modified polyphenylene ether, polyethersulfone, polysulfone, polyamideimide, polyetherimide, polyimide, and polyallylate.

Among them, polyamide, polybutylene terephthalate, polypropylene terephthalate, polyethylene terephthalate, polycarbonate, polyacetal, modified polyphenylene oxide, and modified polyphenylene ether are preferable as engineering plastics from the viewpoint of exhibiting a color-suppressing effect, and polyamide, polybutylene terephthalate, It is polyethylene terephthalate, polycarbonate, or polyacetal, and more preferably polyamide, polybutylene terephthalate, polyethylene terephthalate, or polycarbonate. Depending on the type and use of the resin, the photocuring and / or thermosetting treatment steps can be appropriately performed regardless of the order of the mixing step with the modified cellulose fiber.

In the present specification, polyamide is a general term for polymer compounds formed by amide bonds between monomers, and specific examples of polyamides include polycaproamide (polyamide 6), polyundecaneamide (polyamide 11), and the like. Polydodecaneamide (polyamide 12), polytetramethylene adipamide (polyamide 46), polyhexamethylene adipamide (polyamide 66), polyhexamethylene azelamide (polyamide 69), polyhexamethylene sebacamide (polyamide 610) , Polyhexamethylene dodecamide (polyamide 612), polyundecamethylene adipamide (polyamide 116), polyhexamethylene terephthalamide (polyamide 6T), polynonamethylene terephthalamide (polyamide 9T), polydecamethylene terephthalamide (polyamide 9T) 10T), polyundecamethylene terephthalamide (polyamide 11T), polytrimethylhexamethylene terephthalamide (polyamide TMHT), polyundecamethylene hexahydroterephthalamide (polyamide 11T (H)), polyhexamethylene terephthal / isophthalamide (polyamide) 6T / 6I), polyhexamethylene isophthalamide (polyamide 6I) and polymethaxylylene adipamide (polyamide MXD6). Such a polyamide can be preferably used as an engineering plastic in the present specification.

[Modified cellulose fiber]
The modified cellulose fiber used in the present invention has a cellulose type I crystal, and a specific substituent, that is, a substituent having an aromatic ring is bonded to at least one of the hydroxyl groups derived from cellulose via an ether bond. It is made up of. In addition, in this specification, a compound for bonding a predetermined substituent to a hydroxyl group derived from cellulose via an ether bond is referred to as an "ethering agent".

The specific structure of the modified cellulose fiber used in the present invention can be represented by, for example, the following general formula (Ce).

General formula (Ce):

(In the formula, R is a hydrocarbon group which may independently have hydrogen, a substituent having an aromatic ring, or an oxygen atom, and at least one R is a substituent having an aromatic ring. m preferably represents an integer of 20 or more and 3,000 or less.)

In the general formula (Ce), m is preferably an integer of 20 or more, more preferably an integer of 100 or more, from the viewpoint of developing the mechanical strength of the molded product of the resin composition, while from the viewpoint of availability and cost. , It is preferably an integer of 3,000 or less, and more preferably an integer of 2,000 or less.

(Substituent having an aromatic ring)
In the modified cellulose fiber used in the present invention, it is at least one of R in the general formula (Ce) that a substituent having an aromatic ring is bonded to at least one of the hydroxyl groups derived from cellulose via an ether bond. Means that it is a substituent having an aromatic ring.

Substituents having such an aromatic ring include substituents represented by the following general formula (1), substituents represented by the following general formula (2), and substituents represented by the following general formula (3). One or more substituents selected from the above group are preferred. Among these, from the viewpoint of suppressing color deterioration of the resin composition, the substituent represented by the following general formula (1) or (2) is more preferable, and the substituent represented by the following general formula (2) is further preferable. ..
-CH _2- CH (OH) -R ₁ (1)
-CH _2- CH (OH) -CH _2- (OA) _n- O-R ₁ (2)
-R ₁ (3)
(In the formula, R ₁ in the general formulas (1) to (3) independently represents a hydrocarbon group having at least one aromatic ring and having 6 to 30 carbon atoms, and n in the general formula (2) is A number of 0 or more and 50 or less, A indicates a linear or branched divalent saturated hydrocarbon group having 1 or more and 6 or less carbon atoms.)

R ₁ in the general formulas (1) to (3) is a hydrocarbon group having at least one aromatic ring and having 6 or more and 30 or less carbon atoms. The carbon number of R ₁ is preferably 6 or more from the viewpoint of developing the mechanical strength of the molded product of the resin composition, preferably 25 or less, and more preferably 20 or less from the viewpoint of reactivity and availability. Specific examples of R ₁ include an aryl group such as a phenyl group, a cresyl group, a methoxyphenyl group, a trityl group, a naphthyl group, a tolyl group and a xsilyl group, and an aralkyl group such as a benzyl group and a phenethyl group.

N in the general formula (2) indicates the number of moles of alkylene oxide added. Although n is a number of 0 or more and 50 or less, it is preferably 0 from the viewpoint of availability and cost, and from the same viewpoint, it is preferably 40 or less, more preferably 30 or less, still more preferably 20 or less, still more preferably. Is 15 or less.

A in the general formula (2) is a linear or branched divalent saturated hydrocarbon group having 1 or more and 6 or less carbon atoms, and forms an oxyalkylene group with an adjacent oxygen atom. The carbon number of A is 1 or more and 6 or less, but is preferably 2 or more from the viewpoint of availability and cost, and preferably 4 or less, more preferably 3 or less from the same viewpoint. Specific examples of A include a methylene group, an ethylene group, a propylene group, a butylene group, a pentylene group, a hexylene group and the like. Among them, an ethylene group and a propylene group are preferable, and an ethylene group is more preferable.

The combination of A and n in the general formula (2) is preferably a linear or branched divalent saturated hydrocarbon group having 2 or more and 3 or less carbon atoms, and n is preferably from the viewpoint of availability and cost. It is a combination of numbers of 0 or more and 20 or less, more preferably A is a linear or branched divalent saturated hydrocarbon group having 2 or more and 3 or less carbon atoms, and n is a combination of numbers of 0 or more and 15 or less. ..

(Hydrocarbon group that may have an oxygen atom)
In the general formula (Ce), all Rs may be substituents having an aromatic ring, or at least one of the plurality of Rs may be a substituent having an aromatic ring. In the latter case, R other than the substituent having an aromatic ring is preferably a hydrogen atom or a hydrocarbon group which may have an oxygen atom.

Hydrocarbon groups that may have such an oxygen atom include a substituent represented by the following general formula (4), a substituent represented by the following general formula (5), and the following general formula (6). One or more substituents selected from the group consisting of the represented substituents are preferred.
−CH ₂ −CH (OH) −R ₂ (4)
-CH _2- CH (OH) -CH _2- (OA) _n- O-R ₂ (5)
-R ₃ (6)
(In the formula, R ₂ in the general formulas (4) and (5) is independently hydrogen, or is saturated or unsaturated in a linear, cyclic or branched chain having 1 to 30 carbon atoms and does not contain an aromatic ring. It represents a saturated alkyl group, where n in the general formula (5) is a number of 0 or more and 50 or less, and A is a linear or branched divalent saturated hydrocarbon group having 1 or more and 6 or less carbon atoms. , R ₃ in the general formula (6) represents a saturated or unsaturated alkyl group having 1 to 30 carbon atoms and which does not contain an aromatic ring and has a linear, cyclic or branched chain.)

When R ₂ in the general formulas (4) and (5) is the above-mentioned alkyl group, the carbon number of the alkyl group is preferably 1 or more, more preferably 2 from the viewpoint of the mechanical strength of the molded product of the resin composition. From the viewpoint of reactivity and availability, the amount is preferably 25 or less, more preferably 20 or less. Specific examples of R ₂ include a methyl group, an ethyl group, an allyl group, a propyl group, an isopropyl group, a butyl group, a pentyl group, a hexyl group, a cyclohexyl group, a heptyl group, an octyl group, a 2-ethylhexyl group, nonyl group, decyl Examples thereof include a group, an undecyl group, a dodecyl group, a hexadecyl group, an octadecyl group, an isostearyl group, an oleyl group, and an icosyl group.

N in the general formula (5) indicates the number of moles of alkylene oxide added. The number of n is preferably 0 from the viewpoint of availability and cost, and is preferably 40 or less, more preferably 30 or less, from the same viewpoint and the mechanical strength of the molded product of the obtained resin composition. It is more preferably 20 or less, still more preferably 15 or less, still more preferably 10 or less, still more preferably 5 or less.

A in the general formula (5) 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, and preferably 4 or less, more preferably 3 or less from the same viewpoint. A specific example of A is the same as A in the general formula (2).

The combination of A and n in the general formula (5) is preferably a straight-chain or branched divalent saturated hydrocarbon group having 2 or more and 3 or less carbon atoms, and n is preferably from the viewpoint of availability and cost. It is a combination of numbers of 0 or more and 20 or less, more preferably A is a linear or branched divalent saturated hydrocarbon group having 2 or more and 3 or less carbon atoms, and n is a combination of numbers of 0 or more and 15 or less. ..

The carbon number of the alkyl group of R ₃ in the general formula (6), from the viewpoint of mechanical strength of the molded article of the resin composition, preferably 1 or more, more preferably 2 or more, from the viewpoint of reactivity and availability It is preferably 25 or less, more preferably 20 or less. Specific examples of R ₃ include methyl group, ethyl group, allyl group, propyl group, isopropyl group, butyl group, pentyl group, hexyl group, cyclohexyl group, heptyl group, octyl group, 2-ethylhexyl group, nonyl group and decyl. Examples thereof include a group, an undecyl group, a dodecyl group, a hexadecyl group, an octadecyl group, an isostearyl group, an oleyl group, and an icosyl group.

(Crystallinity)
The crystallinity of the modified cellulose fiber is preferably 10% or more, more preferably 15% or more, still more preferably 20% or more, from the viewpoint of developing the strength of the molded product of the resin composition. Further, from the viewpoint of raw material availability, it is preferably 90% or less, more preferably 85% or less, still more preferably 80% or less, still more preferably 75% or less. In the present 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 described later. The cellulose type I is the crystal form of natural cellulose, and the cellulose type I crystallinity means the ratio of the amount of the crystal region to the whole cellulose. The presence or absence of the cellulose I-type crystal structure can be determined by the peak at 2θ = 22.6 ° in the X-ray diffraction measurement.

(Molar Substituent (MS) of Substituent with Aromatic Ring)
In the modified cellulose fiber, the molar amount (molar substitution degree: MS) to which the substituent having an aromatic ring is bonded to 1 mol of the anhydrous glucose unit of cellulose is preferably 0.001 or more, more preferably, from the viewpoint of dispersibility. It is preferably 0.005 or more, and more preferably 0.03 or more. On the other hand, from the viewpoint of the mechanical strength of the molded product obtained when the modified cellulose fiber is applied to the resin composition, the MS is preferably 1.5 or less, more preferably 1.3 or less. It is more preferably 1.0 or less, still more preferably 0.8 or less. Here, when the substituent having an aromatic ring is composed of a plurality of types of substituents, the MS of the substituent having an aromatic ring is the sum of the MS of each substituent. In addition, in this specification, an anhydrous glucose unit may be abbreviated as "AGU". AGU is calculated assuming that the cellulose raw material is entirely composed of anhydrous glucose units.

(Molar degree of substitution (MS) of hydrocarbon groups that may have oxygen atoms)
When a hydrocarbon group which may have an oxygen atom is bonded to the modified cellulose fiber, a hydrocarbon group which may have an oxygen atom for 1 mol of anhydrous glucose unit of cellulose in the modified cellulose fiber. From the same viewpoint as the substituent having an aromatic ring, the molar amount (molar substitution degree: MS) to which is bonded is preferably 0.001 or more, more preferably 0.005 or more, and further preferably 0. It is 02 or more, preferably 1.5 or less, more preferably 1.3 or less, still more preferably 1.0 or less, still more preferably 0.8 or less. Here, when the hydrocarbon group which may have an oxygen atom is composed of a plurality of kinds of substituents, the MS of the hydrocarbon group which may have an oxygen atom is the sum of the MSs of each substituent. Is.

As used herein, the degree of attachment of substituents (ie, degree of molar substitution (MS)) can be measured according to the method described in Examples below.

(Average fiber diameter)
The average fiber diameter of the modified cellulose fiber used in the present invention is preferably 5 μm or more regardless of the type of substituent. From the viewpoint of handleability, availability, and cost, it is more preferably 7 μm or more, further preferably 10 μm or more, still more preferably 15 μm or more. The upper limit is not particularly set, but from the viewpoint of handleability, it is preferably 10,000 μm or less, more preferably 5,000 μm or less, still more preferably 1,000 μm or less, still more preferably 500 μm or less, still more preferably 100 μm or less. is there.

On the other hand, the modified cellulose fiber used in the present invention may have undergone a miniaturization treatment. In this case, the average fiber diameter of the modified cellulose fiber is nano-order regardless of the type of substituent. The average fiber diameter of the finely divided modified cellulose fibers is preferably 1 nm or more, more preferably 3 nm or more, still more preferably 10 nm or more, still more preferably 20 nm or more, from the viewpoint of handleability, availability, and cost. From the viewpoint of handleability and mechanical strength, it is preferably 500 nm or less, more preferably 300 nm or less, still more preferably 200 nm or less, still more preferably 150 nm or less, still more preferably 120 nm or less.
The average fiber diameter of the modified cellulose fiber can be measured according to the method described in Examples described later.

[Preparation method of modified cellulose fiber]
Such modified cellulose fibers can be produced, for example, by mixing and reacting a compound having an aromatic ring as an etherifying agent with a cellulose raw material in the presence of a base. Hereinafter, a more specific description will be given.

(Cellulose raw material)
The cellulose raw material used in the present invention is not particularly limited, and is wood-based (coniferous / broad-leaved), herbaceous (plant material of rice family, blue-green family, legume family, non-wood raw material of palm family plant), pulps, etc. (Cotton linter pulp obtained from fibers around cotton seeds, etc.), papers (newsprint, cardboard, magazines, woodfree paper, etc.) and the like can be mentioned. Of these, woody and herbaceous are preferable from the viewpoint of availability and cost.

The shape of the cellulose raw material is not particularly limited, but is preferably fibrous, powdery, spherical, chip-shaped, or flake-shaped from the viewpoint of handleability. Moreover, it may be a mixture of these.

Further, the cellulose raw material is previously subjected to at least one pretreatment selected from the biochemical treatment, the chemical treatment, and the mechanical treatment described in paragraphs 0017 to 0018 of JP-A-2018-145571 from the viewpoint of handleability and the like. It can be carried out.

The average fiber diameter of the cellulose raw material is not particularly limited, but is preferably 5 μm or more, more preferably 7 μm or more, still more preferably 10 μm or more, still more preferably 15 μm or more, from the viewpoint of handleability and cost. The upper limit is not particularly set, but from the viewpoint of handleability, it is preferably 10,000 μm or less, more preferably 5,000 μm or less, still more preferably 1,000 μm or less, still more preferably 500 μm or less, still more preferably 100 μm or less. is there. If necessary, fine cellulose fibers having a fiber diameter of 1 to 200 nm that have been subjected to a micronization treatment in advance can also be used.

(Ethering agent for binding a substituent having an aromatic ring)
An etherification reaction is carried out by mixing a cellulose raw material, a base, an etherifying agent for binding a substituent having an aromatic ring, and a solvent if necessary, to bond such a substituent to at least one of cellulose-derived hydroxyl groups. Do.
Preferred etherifying agents for binding substituents having an aromatic ring include, for example, aromatic ring-containing alkylene oxide compounds, aromatic ring-containing glycidyl ether compounds, and aromatic ring-containing organic halogen compounds. Among them, from the viewpoint of availability and reactivity, an aromatic ring-containing alkylene compound and an aromatic ring-containing glycidyl ether compound are more preferable, and an aromatic ring-containing glycidyl ether compound is further preferable.

[Aromatic ring-containing alkylene oxide compound]
Examples of the aromatic ring-containing alkylene oxide compound include those having a structure represented by the following general formula (1A). By using such an etherifying agent, the substituent represented by the general formula (1) can be bonded to the cellulose fiber.

(In the formula, R ₁ is a hydrocarbon group having at least one aromatic ring and having 6 to 30 carbon atoms.)
The carbon number and specific examples of the hydrocarbon group of R ₁ in the general formula (1A) are the same as the carbon number and specific examples of the hydrocarbon group of R ₁ in the general formula (1).

Specific examples of the aromatic ring-containing alkylene oxide compound include styrene oxide and its derivatives. Of these, styrene oxide is preferable from the viewpoint of availability and reactivity.

[Aromatic ring-containing glycidyl ether compound]
Examples of the aromatic ring-containing glycidyl ether compound include those having a structure represented by the following general formula (2A). By using such an etherifying agent, the substituent represented by the general formula (2) can be bonded to the cellulose fiber.

(In the formula, R ₁ is a hydrocarbon group having at least one aromatic ring and having 6 to 30 carbon atoms.)
The carbon number and specific examples of the hydrocarbon group of R ₁ in the general formula (2A) are the same as the carbon number and specific examples of the hydrocarbon group of R ₁ in the general formula (2).

Specific examples of the aromatic ring-containing glycidyl ether compound include phenyl glycidyl ether, methyl phenyl glycidyl ether, methoxyphenyl glycidyl ether, trityl glycidyl ether, benzyl glycidyl ether and derivatives thereof. Among these, phenylglycidyl ether and methylphenylglycidyl ether are preferable, and phenylglycidyl ether is more preferable, from the viewpoint of availability and reactivity.

[Aromatic ring-containing organic halogen compound]
Examples of the aromatic ring-containing organic halogen compound include those having a structure represented by the following general formula (3A). By using such an etherifying agent, the substituent represented by the general formula (3) can be bonded to the cellulose fiber.
X-R ₁ (3A)
(In the formula, X is a halogen atom, and R ₁ is a hydrocarbon group having at least one aromatic ring and having 6 to 30 carbon atoms.)
The carbon number and specific examples of the hydrocarbon group of R ₁ in the general formula (3A) are the same as the carbon number and specific examples of the hydrocarbon group of R ₁ in the general formula (3).

Specific examples of the aromatic ring-containing organic halogen compound include chlorobenzene, benzyl chloride, naphthyl chloride, trityl chloride, derivatives thereof, and chlorine of the above compound substituted with bromine or iodine. Of these, chlorobenzene, benzyl chloride and naphthyl chloride are preferable, and chlorobenzene and benzyl chloride are even more preferable, from the viewpoint of availability and reactivity.

The amount of these etherifying agents can be determined by the desired introduction rate of substituents in the obtained modified cellulose fiber. For example, from the viewpoint of reactivity, the amount of the etherifying agent for one unit of the anhydrous glucose unit of the cellulose raw material is preferably 0.02 equivalent or more, more preferably 0.05 equivalent or more, still more preferably 0.1 equivalent or more. , More preferably 0.3 equivalents or more, still more preferably 1.0 equivalents or more, while preferably 10.0 equivalents or less, more preferably 8.0 equivalents, from the viewpoint of the mechanical strength of the obtained molded product. Hereinafter, it is more preferably 7.0 equivalents or less, still more preferably 6.0 equivalents or less. Here, when a plurality of types of etherifying agents are used as the etherifying agent for binding the substituent having an aromatic ring, the amount of the etherifying agent is the total amount of each etherifying agent.

(Ethering agent for bonding hydrocarbon groups that may have oxygen atoms)
In the present invention, in addition to the etherifying agent (referred to as an etherizing agent (a)), an etherifying agent (ethering agent (b) for binding a hydrocarbon group which may have an oxygen atom). ) And) may be used together. The order in which these etherifying agents and the cellulose raw material are mixed is not particularly limited, and for example, the etherifying agent (a) and the etherifying agent (b) may be mixed at the same time as the cellulose raw material, or ether. The agent (a) may be mixed first, and then the etherifying agent (b) may be mixed, or vice versa. In the present invention, from the viewpoint of increasing the molar substitution degree of the substituent having an aromatic ring, it is preferable to mix the etherifying agent (b) first and then the etherifying agent (a).

Examples of the etherifying agent for binding a hydrocarbon group which may have an oxygen atom include an alkylene oxide compound, a glycidyl ether compound, and a compound having a halogenated hydrocarbon group.

[Alkylene oxide compound]
Examples of the alkylene oxide compound include those having a structure represented by the following general formula (4A). By using such an etherifying agent, the substituent represented by the general formula (4) can be bonded to the cellulose fiber.

(Wherein, _{R 2} is the same as _{R 2} in the above general formula (4).)
The carbon number and specific examples of the hydrocarbon group of R ₂ in the general formula (4A) are the same as the carbon number and specific examples of the hydrocarbon group of R ₂ in the general formula (4).

Specific examples of the compound represented by the general formula (4A) include ethylene oxide, propylene oxide, butylene oxide, 3,4-epoxy-1-butene, 1,2-epoxypentane, 1,2-epoxyhexane, 1, Examples thereof include 2-epoxy-5-hexene, 1,2-epoxy octane, 1,2-epoxy decane, 1,2-epoxy dodecane, 1,2-epoxy tetradecane and 1,2-epoxy octadecane.

[Glysidyl ether compound]
Examples of the glycidyl ether compound include those having a structure represented by the following general formula (5A). By using such an etherifying agent, the substituent represented by the general formula (5) can be bonded to the cellulose fiber.

(Wherein, _{R 2} is the same as _{R 2} in the above general formula (5).)
The carbon number and specific examples of the hydrocarbon group of R ₂ in the general formula (5A) are the same as the carbon number and specific examples of the hydrocarbon group of R ₂ in the general formula (5).

Specific examples of such glycidyl ether compounds include glycidol, methyl glycidyl ether, ethyl glycidyl ether, propyl glycidyl ether, isoprenyl glycidyl ether, allyl glycidyl ether, butyl glycidyl ether, 2-ethylhexyl glycidyl ether, dodecyl glycidyl ether, and (iso) stearyl. Examples thereof include glycidyl ether and glycidyl ether with polyoxyalkylene alkyl ether added.

[Compounds with halogenated hydrocarbon groups]
Examples of the compound having a halogenated hydrocarbon group include a compound having a structure represented by the following general formula (6A). By using such an etherifying agent, the substituent represented by the general formula (6) can be bonded to the cellulose fiber.
X-R ₃ (6A)
(Wherein, X is a halogen atom, _{R 3} is the same as _{R 3} in the general formula (6) described above.)
The number of carbon atoms and specific examples of the hydrocarbon group R ₃ in the general formula (6A) is the same as the carbon number and specific examples of the hydrocarbon group R ₃ in the general formula (6).

Specific examples of the compound represented by the general formula (6A) include chloromethane, chloroethane, 1-chloropropane and its isomer, 1-chlorobutane and its isomer, 1-chloropentane and its isomer, 1-chlorohexane and Its isomers, 1-chlorohexane and its isomers, 1-chlorodecane and its isomers, 1-chlorododecane and its isomers, 1-chlorohexadecan and its isomers, 1-chlorooctadecan and its isomers, 1- Examples thereof include chloroeicosane and its isomers, 1-chlorotriaconsan and its isomers, 1-chloro-5-hexene and its isomers, chlorocyclohexane, and the above compounds in which chlorine is replaced with bromine or iodine. ..

The amount of these etherifying agents can be determined by the desired introduction rate of substituents in the obtained modified cellulose fiber. For example, from the viewpoint of reactivity, the amount of the etherifying agent for one unit of the anhydrous glucose unit of the cellulose raw material is preferably 0.02 equivalent or more, more preferably 0.05 equivalent or more, still more preferably 0.1 equivalent or more. , More preferably 0.3 equivalents or more, still more preferably 1.0 equivalents or more, while preferably 10.0 equivalents or less, more preferably 8.0 equivalents, from the viewpoint of the mechanical strength of the obtained molded product. Hereinafter, it is more preferably 7.0 equivalents or less, still more preferably 6.0 equivalents or less. Here, when a plurality of types of etherifying agents are used as the etherifying agent for binding a hydrocarbon group which may have an oxygen atom, the amount of the etherifying agent is the total amount of each etherifying agent. is there.

(base)
The mixing of the etherifying agent and the cellulose raw material is preferably carried out in the presence of a base. The base used here is not particularly limited, but from the viewpoint of advancing the etherification reaction, alkali metal hydroxide, alkaline earth metal hydroxide, 1-3 amine, quaternary ammonium salt, imidazole and the like. One or more selected from the group consisting of its derivatives, pyridines and derivatives thereof, and alkoxides is preferable. Specific examples of these bases include those described in paragraphs 0024 to 0029 of JP-A-2018-145571.

The amount of the base is preferably 0.01 equivalent or more, more preferably 0.05 equivalent or more, still more preferably 0.1 equivalent or more, from the viewpoint of advancing the etherification reaction with respect to the anhydrous glucose unit of the cellulose raw material. It is more preferably 0.2 equivalents or more, and from the viewpoint of production cost, it is preferably 10 equivalents or less, more preferably 8 equivalents or less, still more preferably 5 equivalents or less, still more preferably 3 equivalents or less.

(solvent)
The etherifying agent and the cellulose raw material may be mixed in the presence of a solvent. The solvent is not particularly limited, and is, for example, water, isopropanol, t-butanol, dimethylformamide, toluene, methyl isobutyl ketone, acetonitrile, dimethyl sulfoxide, dimethylacetamide, 1,3-dimethyl-2-imidazolidinone, hexane, etc. Included are 1,4-dioxane, and mixtures thereof.

The amount of the solvent used is not unconditionally determined depending on the type of the cellulose raw material or the etherifying agent, but is preferably 30 parts by mass or more, more preferably 50 parts by mass with respect to 100 parts by mass of the cellulose raw material from the viewpoint of reactivity. More than parts, more preferably 75 parts by mass or more, still more preferably 100 parts by mass or more, still more preferably 200 parts by mass or more, and from the viewpoint of productivity, preferably 10,000 parts by mass or less, more preferably 7,500 parts by mass. It is less than or equal to parts by mass, more preferably less than 5,000 parts by mass, still more preferably less than 2,500 parts by mass, still more preferably less than 1,000 parts by mass.

(Aetherization reaction)
The etherification reaction between the etherifying agent and the cellulose raw material can be carried out by mixing both, preferably in the presence of a base and / or a solvent.

The mixing conditions are not particularly limited as long as the cellulose raw material and the etherifying agent are uniformly mixed and the reaction can proceed sufficiently, and the continuous mixing treatment may or may not be performed. When a relatively large reaction vessel is used, stirring may be appropriately performed from the viewpoint of controlling the reaction temperature.

The reaction temperature is not unconditionally determined by the type of cellulose raw material or etherifying agent and the target introduction rate, but is preferably 30 ° C. or higher, more preferably 35 ° C. or higher, still more preferably, from the viewpoint of improving reactivity. Is 40 ° C. or higher, preferably 120 ° C. or lower, more preferably 110 ° C. or lower, still more preferably 100 ° C. or lower, still more preferably 90 ° C. or lower, still more preferably 80 ° C. or lower, from the viewpoint of suppressing thermal decomposition. It is preferably 70 ° C. or lower.

The reaction time is not unconditionally determined by the type of cellulose raw material or etherifying agent and the target introduction rate, but from the viewpoint of reactivity, it is preferably 0.1 hours or more, more preferably 0.5 hours or more. It is more preferably 1 hour or more, further preferably 3 hours or more, further preferably 6 hours or more, still more preferably 10 hours or more, and from the viewpoint of productivity, it is preferably 60 hours or less, more preferably 48 hours or less, further. It is preferably 36 hours or less.

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

Thus, a modified cellulose fiber having a cellulose type I crystal and having a substituent having an aromatic ring at at least one of the hydroxyl groups derived from cellulose is bonded via an ether bond to obtain a modified cellulose fiber.

(Miniaturization processing)
The modified cellulose fiber in the present invention may have undergone a micronization treatment. The miniaturization treatment can be carried out by a known miniaturization treatment method. For example, in the case of obtaining a finely modified cellulose fiber having an average fiber diameter of 1 nm or more and 500 nm or less, it is refined by a treatment using a grinder such as a mascoroider or a treatment using a high-pressure homogenizer or the like in a solvent. Can be done.

The timing of performing the micronization treatment is not particularly limited, and may be, for example, before the etherification reaction, after the etherification reaction, or at the same time as the engineering plastic and the modified cellulose fiber are mixed. You can also do it.

The solvent used for the micronization treatment is not particularly limited, but for example, alcohols having 1 to 6 carbon atoms, preferably 1 to 3 carbon atoms such as water, methanol, ethanol and propanol; acetone, methyl ethyl ketone, methyl isobutyl ketone and the like. Ketones with 3 to 6 carbon atoms; linear or branched saturated or unsaturated hydrocarbons with 1 to 6 carbon atoms; aromatic hydrocarbons such as benzene and toluene; halogenated hydrocarbons such as methylene chloride and chloroform; Lower alkyl ethers having 2 to 5 carbon atoms; polar solvents such as N, N-dimethylformamide (DMF), N, N-dimethylacetamide, dimethylsulfoxide, diesters of succinic acid and triethylene glycol monomethyl ether, etc. are exemplified. .. The amount of the solvent used may be an effective amount capable of dispersing the modified cellulose fibers and is not particularly limited, but is preferably 1% by mass or more, more preferably 2% by mass or more, preferably 2% by mass or more, based on the modified cellulose fibers. Is more preferably 500 times by mass or less, more preferably 200 times by mass or less.

Further, as an apparatus used in the miniaturization process, a known disperser is preferably used in addition to the high-pressure homogenizer. For example, a breaker, a beater, a low-pressure homogenizer, a grinder, a mascoroider, a cutter mill, a ball mill, a jet mill, a short-screw extruder, a twin-screw extruder, an ultrasonic stirrer, a household juicer mixer and the like can be used. Further, the solid content concentration of the modified cellulose fiber in the miniaturization treatment is preferably 50% by mass or less.

By such a miniaturization treatment, a modified cellulose fiber having a nano-order average fiber diameter specified above can be produced.

[Resin composition]
The content of the engineering plastic in the resin composition of the present invention is preferably 10% by mass or more, more preferably 20% by mass or more, still more preferably 30% by mass, from the viewpoint of obtaining the physical properties of the engineering plastic itself. The above is more preferably 40% by mass or more, further preferably 50% by mass or more, still more preferably 60% by mass or more. On the other hand, from the same viewpoint, it is preferably 99.95% by mass or less, more preferably 99.9% by mass or less, preferably 99.7% by mass or less, and more preferably 99.5% by mass or less. It is more preferably 99% by mass or less.

The content of the modified cellulose fiber in the resin composition of the present invention is preferably 0.05% by mass or more as the amount of cellulose fiber (converted amount) from the viewpoint of heat resistance and the mechanical strength of the molded product of the resin composition. It is more preferably 0.1% by mass or more, preferably 0.3% by mass or more, more preferably 0.5% by mass or more, and further preferably 1% by mass or more. On the other hand, from the viewpoint of suppressing color deterioration, it is preferably 90% by mass or less, more preferably 80% by mass or less, further preferably 70% by mass or less, still more preferably 60% by mass or less, still more preferably. Is 50% by mass or less, more preferably 40% by mass or less. The amount of cellulose fiber (converted amount) refers to the mass obtained by subtracting the mass of the substituent from the mass of the modified cellulose fiber. The amount of cellulose fibers (converted amount) in the modified cellulose fibers can be measured by the method described in Examples described later.

The content of the modified cellulose fiber in the resin composition of the present invention is preferably 0.06 part by mass with respect to 100 parts by mass of the engineering plastic from the viewpoint of heat resistance and mechanical strength of the molded product of the resin composition. The above is more preferably 0.12 parts by mass or more, further preferably 0.36 parts by mass or more, still more preferably 0.6 parts by mass or more, still more preferably 1 part by mass or more. On the other hand, from the viewpoint of manufacturing cost, it is preferably 120 parts by mass or less, more preferably 100 parts by mass or less, still more preferably 60 parts by mass or less, still more preferably 40 parts by mass or less, still more preferably 20 parts by mass or less. Is.

The resin composition of the present invention may contain additives commonly used in the field of the present invention. Such additives include compatibilizers, crystal nucleating agents, inorganic fillers, organic fillers, hydrolysis inhibitors, impact resistant improvers, flame retardants, antioxidants, lubricants, antistatic agents, and antifogging agents. , Hardeners, dyes, pigments, plasticizers, catalysts, fungicides, defoamers, leveling agents, pigment dispersants, anti-settling agents, anti-dripping agents, thickeners, matting agents, light stabilizers, UV absorption Agents and the like can be mentioned. The content of such an additive in the resin composition cannot be unequivocally determined depending on the type of engineering plastic and the additive used, but is preferably 0.001% by mass or more from the viewpoint of exhibiting the effect of the additive. It is preferably 0.01% by mass or more, more preferably 0.1% by mass or more, and preferably 30% by mass or less, more preferably 15% by mass or less, still more preferably, from the viewpoint of not impairing the physical properties of the resin composition. It is 5% by mass or less.

<Manufacturing method of resin composition>
The method for producing a resin composition of the present invention is a production method including a mixing step of mixing the engineering plastic and the modified cellulose fiber.

[Mixing process]
The mixing step is performed by melt-kneading each of the above-mentioned components using a known kneader such as a closed kneader, a single-screw extruder, a roll mill, or an open-roll kneader, or a solvent casting method. This can be carried out by shearing with a shearing device such as a high shearing machine.

Preferably, the present mixing step includes a step of performing a shearing treatment and / or a kneading treatment at 200 ° C. or higher, more preferably 220 ° C. or higher, still more preferably 250 ° C. or higher, and by carrying out such treatment, This mixing step can be easily carried out.

As the engineering plastic and the modified cellulose fiber in the mixing step, the engineering plastic and the modified cellulose fiber in the resin composition of the present invention described above are applied.

The blending amount of the modified cellulose fiber in the mixing step is preferably 0.06 part by mass or more, more preferably 0.06 part by mass or more, based on 100 parts by mass of the engineering plastic, from the viewpoint of exhibiting mechanical properties in the molded body of the resin composition. It is 0.12 parts by mass or more, more preferably 0.36 parts by mass or more, further preferably 0.6 parts by mass or more, and further preferably 1 part by mass or more. On the other hand, from the viewpoint of manufacturing cost, it is preferably 120 parts by mass or less, more preferably 100 parts by mass or less, still more preferably 60 parts by mass or less, still more preferably 40 parts by mass or less, still more preferably 20 parts by mass or less. Is.

The blending amount of the cellulose fibers (converted amount) in the resin composition is preferably 0.05 parts by mass or more with respect to 100 parts by mass of the engineering plastic from the viewpoint of exhibiting mechanical properties in the molded body of the resin composition. , More preferably 0.1 part by mass or more, further preferably 0.3 part by mass or more, still more preferably 0.5 part by mass or more, still more preferably 1 part by mass or more. On the other hand, from the viewpoint of manufacturing cost, it is preferably 60 parts by mass or less, more preferably 50 parts by mass or less, still more preferably 30 parts by mass or less, still more preferably 20 parts by mass or less, still more preferably 10 parts by mass or less. Is.

<Resin molded product>
The resin molded product in the present invention may appropriately use a known molding method such as extrusion molding, injection molding, press molding, or casting molding using the resin composition of the present invention or the resin composition produced by the production method of the present invention. It can be manufactured by using it. Since the resin composition of the present invention is excellent in suppressing color deterioration during molding, the resin molded product can be suitably used for various purposes.

The degree of coloring of the resin molded product can be evaluated by the YI (Yellow Index) value described in Examples described later, and the smaller the ΔYI value, the stronger the suppression of coloring deterioration.

The application in which the resin composition or resin molded product of the present invention can be used is not particularly limited, but for example, information home appliance parts, packing materials for information home appliance parts, automobile parts, 3 which require high heat resistance, mechanical strength and durability. It can be used for various industrial applications such as three-dimensional molding materials, cushioning materials, repair materials, sealing materials, heat insulating materials, and sound absorbing materials.

Hereinafter, the present invention will be specifically described with reference to Examples and the like. It should be noted that these examples and the like are merely examples of the present invention and do not mean any limitation. The part in the example is a mass part unless otherwise specified. The "normal pressure" indicates 101.3 kPa, and the "room temperature" indicates 25 ° C.

[Average fiber diameter of various cellulose fibers]
(1) When the average fiber diameter of the cellulose fiber to be measured is expected to be several nanometers to several hundred nanometers, the average fiber diameter of the cellulose fiber is obtained as follows.
An appropriate solvent is added to the cellulose fibers to be measured to prepare a dispersion having a concentration of 0.0001% by mass. Atomic force microscope (AFM) (Digital instrument, Nanoscope III Tapping mode AFM, probe is Nanosensors, Point Probe) is used as an observation sample after dropping the dispersion on mica (mica) and drying it. (Using (NCH)) is used to measure the fiber height of the cellulose fibers in the observation sample. The suitable solvent may be any solvent that swells the cellulose fiber to be measured, and is preferably water or ethanol in the case of a cellulose raw material, DMF or toluene in the case of a modified cellulose fiber, or the like. At that time, in a microscope image in which the cellulose fibers can be confirmed, 100 or more cellulose fibers are extracted, and the average fiber diameter is calculated from the fiber heights thereof. The average fiber length is calculated from the distance in the fiber direction. The average aspect ratio is calculated from the average fiber length / average fiber diameter, and the standard deviation is also calculated. In general, the smallest unit of cellulose nanofibers prepared from higher plants is that 6 × 6 molecular chains are packed in a nearly square shape, so the height analyzed by AFM images should be regarded as the fiber width. Can be done.

(2) When the average fiber diameter of the cellulose fiber to be measured is expected to be several hundred nanometers to several thousand micrometers, the average fiber diameter of the cellulose fiber is calculated as follows.
A medium is added to the cellulose fibers 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 Jasco International Co., Ltd., trade name: IF-3200), the dispersion is used for front lens: 2x, telecentric zoom lens: 1x, image resolution: 0.835 μm / pixel. , Syringe inner diameter: 6515 μm, spacer thickness: 500 μm, image recognition mode: ghost, threshold: 8, analytical sample volume: 1 mL, sampling: 15%. 100 or more cellulose fibers are measured, and the average ISO fiber diameter thereof is taken as the average fiber diameter, and the average ISO fiber length is calculated as the average fiber length. The average aspect ratio is calculated from the average fiber length / average fiber diameter, and the standard deviation is also calculated.

[Confirmation of crystal structure of cellulose fibers]
The crystal structure of cellulose fibers such as cellulose raw materials and modified cellulose fibers is confirmed by measuring under the following conditions using a diffractometer (manufactured by Rigaku Co., Ltd., trade name: MiniFlexII).
Measurement pellet preparation conditions: Smooth pellets with an area of 320 mm ² x thickness of 1 mm are prepared by applying pressure to the target cellulose fibers in the range of 10 to 20 MPa with a tablet molding machine.
X-ray diffraction analysis conditions: step angle 0.01 °, scan speed 10 ° / min, measurement range: diffraction angle 2θ = 5-40 °
X-ray source: Cu / Kα-radiation, tube voltage: 15 kv, tube current: 30 mA
Peak division condition: After removing the background noise, fitting is performed by a Gaussian function so that the error between 2θ = 13-23 ° is within 5%.
The crystal structure of the modified cellulose fiber is confirmed by measuring under the above-mentioned conditions using the above-mentioned diffractometer.

The crystallinity of the cellulose type I crystal structure is calculated based on the following formula (A) using the area of the X-ray diffraction peak obtained by the above-mentioned peak division.
Cellulose type I crystallinity (%) = [I _cr / (I _cr + I _am )] × 100 (A)
[In the formula, 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 area of the amorphous part (diffraction angle 2θ = 18.5 °). The area of the diffraction peak is shown. ]

[Measurement of MS]
First, the content% (mass%) of the substituent contained in the cellulose fiber to be measured is described in Analytical Chemistry, Vol. 51, No. 13, 2172 (1979), "15th Amendment of the Japanese Pharmacy (1979). It is calculated according to the Zeisel method, which is known as a method for analyzing the average number of added moles of alkoxy groups of cellulose ether described in "Analytical method of hydroxypropyl cellulose"). The procedure is shown below.

(i) Add 0.1 g of n-tetradecane to a 200 mL volumetric flask and perform volumetric up to the marked line with hexane to prepare an internal standard solution.
(ii) 70 mg of purified and dried cellulose fiber to be measured and 80 mg of adipic acid are precisely weighed in a 10 mL vial, and 2 mL of hydrogen iodide is added and sealed.
(iii) The mixture in the vial is 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 are sequentially injected into the vial, and the mixture is stirred at room temperature for 1 minute.
(v) The upper layer (diethyl ether layer) of the mixture separated into two phases in the vial is analyzed by gas chromatography (manufactured by SHIMADZU, trade name: GC2010Plus).
(vi) The analysis was performed in the same manner as in (ii) to (v) except that the cellulose fiber to be measured was changed to the etherifying agent 5 mg, 10 mg, and 15 mg used for the modification, respectively, and the etherifying agent was used. Create a calibration curve for.
(vii) Quantify the substituents contained in the cellulose fiber to be measured from the prepared calibration curve and the analysis result of the cellulose fiber to be measured. The analysis conditions are as follows.

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

Next, the molar substitution degree (MS) is calculated from the obtained substituent content using the following formula (B) or (C). When there is one type of introduced substituent, the formula (B) is used to calculate the MS, and when there are two types of introduced substituents, the formula (C) is used to calculate the MS.
Formula (B)
MS = (W / Mw) / ((100-W ₁ ) /162.14)
W: Content of substituent in the cellulose fiber to be measured (mass%)
Mw: Molecular weight of the etherifying agent used (g / mol)

Formula (C)
MS ₁ = (W ₁ / Mw ₁ ) / ((100-W ₁ -W ₂ ) /162.14)
MS ₂ = (W ₂ / Mw ₂ ) / ((100-W ₁ -W ₂ ) /162.14)
MS ₁ : MS of the first type of substituent
MS ₂ : MS of the second type of substituent
W ₁ : Content of the first type of substituent in the cellulose fiber to be measured (mass%)
W ₂ : Content (mass%) of the second type of substituent in the cellulose fiber to be measured
Mw ₁ : Molecular weight of the first type of etherifying agent (g / mol)
Mw ₂ : Molecular weight of the second type of etherifying agent (g / mol)

[Amount of cellulose fibers in modified cellulose fibers (converted amount)]
The cellulose fiber (converted amount) in the modified cellulose fiber is calculated by the following formula.
Cellulose fiber amount (converted amount) (g) = 162 / (162 + molecular weight of etherifying agent used (g / mol) × MS) × mass of modified cellulose fiber (g)
When two or more types of etherifying agents are added, the total product of the molecular weight of each etherifying agent and the MS is calculated to calculate the amount of cellulose fibers (converted amount).

[Manufacturing of molded products]
The target resin or resin composition is injection-molded using an injection molding machine (manufactured by Japan Steel Works, Ltd., trade name: J110AD-180H, cylinder temperature setting at 6 locations). The cylinder temperature is set to 280 ° C. from the nozzle tip side to the fifth unit, the remaining one unit is set to 250 ° C., the temperature under the hopper is set to 45 ° C., and the mold temperature is set to 80 ° C. to manufacture a molded product having a desired shape.

[Thermal deformation temperature of crystalline resin]
The thermal deformation temperature of the crystalline resin is measured as follows.
The resin to be evaluated is injection-molded by the method described in the above-mentioned [Manufacturing of molded product] to prepare a prismatic test piece (125 mm × 13 mm × 6.4 mm). This prismatic test piece was edgewise, heated at a temperature of 2 ° C./min, using a heat distortion temperature measuring machine (manufactured by Yasuda Seiki Seisakusho, fully automatic heat distortion tester / No. 148-HDA6) based on ASTM D648. Under the condition of low load (0.45 MPa), the deflection temperature under load (DTUL) when bent by 0.254 mm is measured, and this is taken as the heat distortion temperature.

[Glass transition temperature of amorphous resin]
The glass transition temperature of the amorphous resin is measured as follows.
Using a differential scanning calorimeter (DSC Q20, manufactured by TA Instruments Japan), weigh 0.01 to 0.02 g of the sample into an aluminum pan and raise the temperature to 200 ° C. The temperature is cooled to 0 ° C. at a temperature lowering rate of 10 ° C./min. Next, the temperature of the sample is raised at a heating rate of 10 ° C./min, and the endothermic peak is measured. The temperature at the intersection of the extension of the baseline below the maximum peak temperature of heat absorption and the tangent line indicating the maximum slope from the rising portion of the peak to the peak of the peak is defined as the glass transition temperature.

[Tensile strength of engineering plastics]
The tensile strength of engineering plastics is measured as follows.
The resin to be evaluated is injection-molded by the method described in the above-mentioned [Manufacturing of molded product] to prepare a dumbbell type test piece (ISO527, type 1A). Based on ISO527, this dumbbell type test piece was subjected to a tensile test using an autograph (SHIMADZU, Autograph precision universal testing machine, AGS-10kNX) at a tensile speed of 50 mm / min, and the tensile strength was set. (Yield point stress) is calculated.

[Flexural modulus of engineering plastics]
The flexural modulus of engineering plastics is measured as follows.
The resin to be evaluated is injection-molded by the method described in the above-mentioned [Manufacturing of molded product] to prepare a prismatic test piece (125 mm × 13 mm × 6.4 mm). Based on ASTM D790, this prismatic test piece was subjected to a bending test using Tensilon (Orientec, Tensilon universal testing machine, RTC-1210A) with the crosshead speed set to 3 mm / min, and the flexural modulus was set. Find the rate.

<Manufacturing of modified cellulose fiber>
Production Example 1 of Modified Cellulose Fiber
Bleached kraft pulp of absolutely dried conifer (hereinafter abbreviated as NBKP, manufactured by West Frezer, "Hinton", fibrous, cellulose content 90% by mass, water content 5% by mass) 6.4% by mass in 250.0g 267.1 g (0.28 equivalent of NaOH / AGU) of aqueous sodium hydroxide solution was added and mixed uniformly. Then, 333.8 g of butylene oxide (manufactured by Wako Pure Chemical Industries, Ltd., 3.0 eq / AGU) was added as an etherifying agent, and after sealing, the mixture was stirred at 50 ° C. for 7 hours using a kneader rotating device to react. went. After the reaction, it is neutralized with acetic acid and thoroughly washed with ion-exchanged water until the conductivity of the filtrate is measured by a compact electric conductivity meter (LAQUAtwin EC-33B, manufactured by HORIBA, Ltd.) to 50 μs / cm or less. Further, impurities were removed by thoroughly washing with 5 L of acetone. Then, vacuum drying was carried out at 70 ° C. overnight to obtain a modified cellulose fiber 1 in which a 2-hydroxybutyl group as a substituent was bonded to a hydroxyl group derived from cellulose via an ether bond (degree of substitution (substituent (degree of substitution (substituent) MS) is listed in the table. The same shall apply hereinafter).

Production Example 2 of Modified Cellulose Fiber
In addition to 14.0 g of the modified cellulose fiber obtained in Production Example 1, 42.3 g (2.97 eq / AGU) of a 6.4 mass% sodium hydroxide aqueous solution and 0.5 g of Coatamine D2345P (manufactured by Kao Corporation, 0). .04 eq / AGU) was added and mixed uniformly. Then, 11.2 g of o-methylphenylglycidyl ether (manufactured by Sigma-Aldrich, 3.0 eq / AGU) was added as an etherifying agent, and the mixture was sealed. Then, the reaction was carried out in a vial at 70 ° C. for 24 hours. After the reaction, it was washed with acetone, neutralized with acetic acid, and ion-exchanged water was used until the conductivity of the filtrate was measured by a compact electric conductivity meter (LAQUAtwin EC-33B, manufactured by HORIBA, Ltd.) to 50 μs / cm or less. After thorough washing, impurities were removed by washing thoroughly with 1 L of acetone. Then, vacuum drying was carried out at 70 ° C. overnight to obtain a modified cellulose fiber 2 in which a substituent having an aromatic ring was bonded to a hydroxyl group derived from cellulose via an ether bond. The average fiber diameter of the modified cellulose fiber 2 was 22 μm.

Production Example 3 of Modified Cellulose Fiber
Cellulose-derived by performing the same operation as in Production Example 2 of modified cellulose except that the amount of the etherifying agent (o-methylphenylglycidyl ether) used was changed to 18.7 g (5.0 equivalent / AGU). A modified cellulose fiber 3 was obtained in which a substituent having an aromatic ring was bonded to the hydroxyl group of the above via an ether bond.

Production Example 4 of Modified Cellulose Fiber
The same operation as in Production Example 2 of modified cellulose was performed except that the type and amount of the etherifying agent used was changed to phenylglycidyl ether (manufactured by Tokyo Chemical Industry Co., Ltd.) and 17.1 g (5.0 equivalents / AGU). By doing so, a modified cellulose fiber 4 in which a substituent having an aromatic ring was bonded to a hydroxyl group derived from cellulose via an ether bond was obtained.

Production Example 5 of Modified Cellulose Fiber
To 4.0 g of the modified cellulose fiber obtained in Production Example 1, 4.3 g (NOOH 0.30 equivalent / AGU) of 6.4 mass% sodium hydroxide aqueous solution and 36 g of 2-propanol were added and mixed uniformly. .. Then, 3.9 g of lauryl glycidyl ether (manufactured by Tokyo Chemical Industry Co., Ltd., 0.7 equivalent / AGU) was added as an etherifying agent, and the mixture was sealed. Then, the reaction was carried out in a vial at 70 ° C. for 24 hours. After the reaction, it was washed with acetone, neutralized with acetic acid, and ion-exchanged water was used until the conductivity of the filtrate was measured by a compact electric conductivity meter (LAQUAtwin EC-33B, manufactured by HORIBA, Ltd.) to 50 μs / cm or less. After thorough washing, impurities were removed by washing thoroughly with 1 L of acetone. Then, vacuum drying was carried out at 70 ° C. overnight to obtain a modified cellulose fiber 5 in which a dodecyl group as a substituent was bonded to a hydroxyl group derived from cellulose via an ether bond.

Table 2 summarizes the properties of NBKP and the modified cellulose fibers for each of the above production examples. The blending amount of each material constituting the resin composition in Table 2 is a part by mass.

<Manufacturing of resin composition: Polycarbonate>
Examples 1-4
Each material shown in Table 2, that is, polycarbonate as an engineering plastic, modified cellulose fibers 2 to 4, and optionally a compatibilizer are combined as shown in Table 2 to form a twin-screw kneader (manufactured by Japan Steel Works, Ltd.). , Trade name: TEX28V (screw diameter 28 mm, L / D = 42)) was melt-kneaded at a discharge rate of 10 kg / h, a rotation speed of 200 rpm, and 280 ° C. to obtain a resin composition. The pellets of the obtained resin composition were dehumidified and dried at 120 ° C. for 2 hours or more so that the moisture value was 100 ppm or less.

Comparative Examples 1-3
NBKP, which is a cellulose raw material, was used instead of the modified cellulose fiber (Comparative Example 1), the modified cellulose fiber 1 was used as the modified cellulose fiber (Comparative Example 2), or the modified cellulose was used as the modified cellulose fiber. Pellets of the resin composition were obtained in the same manner as in the above Examples except that the fiber 5 was used (Comparative Example 3).

<Manufacturing of molded product: Examples 1 to 4, Comparative Examples 1 to 3>
The obtained resin composition was injection-molded by the method described in the above-mentioned [Manufacturing of molded product] to form a flat plate test piece (70 mm × 40 mm × 3 mm) to obtain a molded product of the resin composition.

Details of materials, abbreviations, etc. in the examples are as follows.
〔resin〕
PC: Bisphenol A polycarbonate resin (amorphous resin), manufactured by Idemitsu Kosan Co., Ltd., trade name: Toughlon A1900

[Compatible agent]
Modiper CL430-G: Manufactured by NOF CORPORATION, the main chain is polycarbonate, and the side chain is a graft polymer of glycidiroustyrene methacrylate-acrylonitrile copolymer.

Test Example 1 <YI (Yellow Index) value>
The YI value of the flat plate test piece of each molded product obtained by using the resin compositions of the above Examples and Comparative Examples was measured with a color difference meter (manufactured by Nippon Denshoku Industries Co., Ltd., SE2000). The value obtained by subtracting the YI of the blank resin from the YI value of the resin composition was taken as the ΔYI value. The smaller the value, the better the hue and the better the thermal stability. Here, the blank resin refers to a resin or resin composition that does not contain modified cellulose fibers.

From Table 2, it was found that the ΔYI value in Comparative Example 1 using the non-modified cellulose fiber, that is, the cellulose raw material was very large, and the molded product in Comparative Example 1 was considerably colored and deteriorated. In Comparative Examples 2 and 3 using the modified cellulose fiber outside the scope of the present invention, although the ΔYI value was smaller than that in Comparative Example 1, the degree of color deterioration of the molded product was large, and it was visible to the naked eye that the color was deteriorated. But I could confirm it clearly.

On the other hand, in the examples using the modified cellulose fiber within the range of the present invention, the ΔYI value was small, and even if the degree of color deterioration of the molded product was confirmed with the naked eye, the difference from the blank resin could be slightly confirmed. Met.

From Example 1 and Comparative Example 3, although the number of carbon atoms of the substituent is larger in Comparative Example 3, the ΔYI value is clearly smaller in Example 1 having a substituent having an aromatic ring. I understood. From this, it was suggested that the degree of color deterioration in the molded product is greatly influenced by the structure of the substituent, particularly whether or not it has an aromatic ring, rather than the carbon number of the substituent in the modified cellulose fiber.

Production Example 6 of Modified Cellulose Fiber
Cellulose-derived by performing the same operation as in Production Example 2 except that the amount of o-methylphenylglycidyl ether as an etherifying agent was changed to 18.7 g (manufactured by Sigma-Aldrich, 5.0 equivalent / AGU). A modified cellulose fiber 6 was obtained in which a substituent having an aromatic ring was bonded to the hydroxyl group of the above via an ether bond.

<Manufacturing of resin composition: polybutylene terephthalate>
Example 5
Each material is melt-kneaded in a nitrogen atmosphere at a rotation speed of 90 rpm and 240 ° C. for 10 minutes using a kneader (Laboplast Mill manufactured by Toyo Seiki Seisakusho Co., Ltd.) at the amount of preparation shown in Table 6, and the resin composition is prepared. Got

Comparative Example 4
A resin composition was obtained in the same manner as in Example 5 except that NBKP, which is a cellulose raw material, was used instead of the modified cellulose fiber.

<Manufacturing of resin composition: Polyamide 6>
Example 6
A resin composition was obtained in the same manner as in Example 5 except that the resin used was changed to polyamide 6.

Comparative Example 5
A resin composition was obtained in the same manner as in Example 6 except that NBKP, which is a cellulose raw material, was used instead of the modified cellulose fiber.
<Manufacturing of resin composition: Polyamide 66>

Example 7
A resin composition was obtained in the same manner as in Example 5 except that the resin used was changed to polyamide 66 and the kneading conditions were changed to the temperatures shown in Table 8.

Comparative Example 6
A resin composition was obtained in the same manner as in Example 7 except that NBKP, which is a cellulose raw material, was used instead of the modified cellulose fiber.

<Manufacturing of molded product: Examples 5 to 7, Comparative Examples 4 to 6>
The obtained resin composition was molded into a sheet having a thickness of 0.4 mm under the following conditions using an auto press molding machine (manufactured by Toyo Seiki Seisakusho) and a spacer of 0.4 mm to form a molded body of the resin composition. did. The press conditions are as follows.
Pressing was performed at 0.5 MPa for 2 minutes at various temperatures (PBT: 250 ° C., PA6: 240 ° C., PA66: 280 ° C.) depending on the resin used, and then pressed at 20 MPa for 1 minute without changing the temperature. Subsequently, a hand press was used at 10 MPa, 80 ° C. for 1 minute, and then the resin composition was pressed at 15 ° C. for 20 seconds to prepare a sheet of each resin composition.

Details of materials, abbreviations, etc. in the examples are as follows.
〔resin〕
Polybutylene terephthalate (PBT): DURANEX 700FP (manufactured by Polyplastics)

Polyamide 6 (PA6): Amiran CM1017 (manufactured by Toray Industries, Inc.)

Polyamide 66 (PA66): Amiran CM3001-N (manufactured by Toray Industries, Inc.)

Test Example 2 <YI (Yellow Index) value>
The YI value of each sheet molded product obtained by using the resin compositions of Examples 5 to 7 and Comparative Examples 4 to 6 was measured in the same manner as in Test Example 1 to determine the ΔYI value.

Tables 6 to 8 summarize the properties of the modified cellulose fiber 6 and the compositions and results of Examples 5 to 7 and Comparative Examples 4 to 6. The blending amount of each material constituting the resin composition in these tables is by mass.

From Examples 5 to 7 and Comparative Examples 4 to 6, it was confirmed that even when the specific modified cellulose fiber of the present invention was applied to an engineering plastic other than polycarbonate, the effect of suppressing color deterioration was exhibited as in the case of polycarbonate. ..

The resin composition of the present invention is, for example, an information home appliance part that requires high heat resistance, mechanical strength and durability, a packing material for an information home appliance part, an automobile part, a three-dimensional modeling material, a cushion material, a repair material, and a sealing material. It can be used for various industrial applications such as materials, heat insulating materials, and sound absorbing materials.

Claims (11)

A resin composition containing engineering plastics and modified cellulose fibers.
A resin composition in which the modified cellulose fiber has a cellulose type I crystal, and a substituent having an aromatic ring at at least one of the hydroxyl groups derived from cellulose is bonded via an ether bond. The resin composition according to claim 1, wherein the engineering plastic is a crystalline resin. The resin composition according to claim 2, wherein the engineering plastic has a thermal deformation temperature of 100 ° C. or higher. The resin composition according to claim 1, wherein the engineering plastic is an amorphous resin. The resin composition according to claim 4, wherein the engineering plastic has a glass transition temperature of 100 ° C. or higher. The resin composition according to any one of claims 1 to 5, wherein the engineering plastic has a tensile strength of 49 MPa or more at 25 ° C. The resin composition according to any one of claims 1 to 6, wherein the engineering plastic has a flexural modulus of 2 GPa or more at 25 ° C. The engineering plastics are polyamide, polybutylene terephthalate, polyethylene terephthalate, polycarbonate, polyacetal, modified polyphenylene oxide, modified polyphenylene ether, polyphenylene sulfide, polyetheretherketone, polyethersulfone, polysulfone, polyamideimide, polyetherimide, polyimide, poly. The resin composition according to any one of claims 1 to 7, which is one or more selected from the group consisting of allylate and polyallyl ether nitrile. A group in which a substituent having an aromatic ring consists of a substituent represented by the following general formula (1), a substituent represented by the following general formula (2), and a substituent represented by the following general formula (3). The resin composition according to any one of claims 1 to 8, which is one or more substituents selected from the above.
-CH _2- CH (OH) -R ₁ (1)
-CH _2- CH (OH) -CH _2- (OA) _n- O-R ₁ (2)
-R ₁ (3)
(In the formula, R ₁ in the general formulas (1) to (3) independently represents a hydrocarbon group having at least one aromatic ring and having 6 to 30 carbon atoms, and n in the general formula (2) is A number of 0 or more and 50 or less, A indicates a linear or branched divalent saturated hydrocarbon group having 1 or more and 6 or less carbon atoms.) A method for producing a resin composition, which comprises a mixing step of mixing engineering plastics and modified cellulose fibers.
A method for producing a resin composition, wherein the modified cellulose fiber has a cellulose type I crystal, and a substituent having an aromatic ring at at least one of the hydroxyl groups derived from cellulose is bonded via an ether bond. .. The method for producing a resin composition according to claim 10, wherein the mixing step includes a step of performing a shearing treatment and / or a kneading treatment at 200 ° C. or higher.