JP5797129B2 - Dispersion liquid containing cellulose nanofiber and resin, and resin composition - Google Patents

Description

  The present invention relates to a dispersion containing cellulose nanofibers and a resin, and a resin composition containing cellulose nanofibers and a resin.

  2. Description of the Related Art Conventionally, in a molding material using a resin, a technique of adding a reinforcing material to the resin has been taken in order to increase the reinforcing property of the resin, and cellulose nanofibers are known as the reinforcing material. Cellulose nanofibers have a large specific surface area and an excellent reinforcing effect compared to general cellulose fibers, but on the other hand, the surface of cellulose nanofibers has many hydroxyl groups, so it is a highly hydrophobic resin. When they are mixed with each other, agglomeration occurs in the resin component, and the reinforcing effect is rather reduced.

  For example, Patent Document 1 proposes a method of hydrophobically modifying microfibrillated plant fibers for the purpose of improving the adhesion of the microfibrillated plant fibers to the resin. In Patent Document 2, for the purpose of obtaining a composite resin having excellent dispersibility of microfibrillated cellulose, a dispersion in which microfibrillated cellulose is dispersed in water is prepared, and then a resin powder is dispersed in the dispersion. There has been proposed a method of removing the dispersion medium after the treatment. However, if the specific surface area is extremely high, aggregation tends to occur between the cellulose nanofibers and the thermoplastic resin, and the intended high-strength material may not be obtained. In addition, there is still room for investigation to prepare a dispersion in which cellulose nanofibers having high hydrophilicity and a resin having high hydrophobicity are more uniformly dispersed to obtain a resin composition having excellent dispersibility of cellulose nanofibers. is there.

  As described above, it is required to more uniformly disperse both the highly hydrophilic cellulose nanofiber and the highly hydrophobic resin in the dispersion.

JP 2011-213754 A JP 2008-297364 A

  An object of the present invention is to provide a dispersion in which both cellulose nanofibers and a resin are uniformly dispersed in a dispersion medium, and a resin composition in which cellulose nanofibers are uniformly contained in the resin. .

  As a result of intensive studies to solve the above problems, the present inventors have added a nonionic surfactant having an HLB value in a specific range in a dispersion containing cellulose nanofibers and a thermoplastic resin. It has been found that both cellulose nanofibers and thermoplastic resin can be uniformly dispersed in a dispersion medium, and the present invention has been completed.

  That is, the present invention relates to the following dispersion and resin composition.

  Item 1. A dispersion containing cellulose nanofiber (A), a thermoplastic resin (B), and a nonionic surfactant (C) having an HLB value of 8 to 13.

  Item 2. Item 2. The dispersion according to Item 1, wherein the cellulose nanofiber (A) is dyed.

  Item 3. Item 3. The dispersion according to Item 1 or 2, wherein the thermoplastic resin (B) is at least one selected from the group consisting of polypropylene, polyethylene, and polyamide.

  Item 4. The resin composition obtained from the dispersion liquid in any one of said items 1-3.

  Item 5. A resin composition comprising a dyed cellulose nanofiber (A1) and a thermoplastic resin (B).

Item 6. (1) a step of dyeing cellulose nanofiber (A),
(2) In the dispersion medium (D), the cellulose nanofiber (A1) dyed in Step 1, the thermoplastic resin (B), and the nonionic surfactant (C) having an HLB value of 8 to 13 are mixed, A method for producing a resin composition comprising a step of preparing a dispersion, and (3) a step of removing a dispersion medium from the dispersion.

  Hereinafter, the dispersion and the resin composition of the present invention will be described in detail.

<Dispersion>
The dispersion of the present invention contains cellulose nanofiber (A), a thermoplastic resin (B), and a nonionic surfactant (C) having an HLB value of 8 to 13.

Cellulose nanofiber (A)
Cellulose fiber (CF) used as a raw material of cellulose nanofiber (A) contained in the dispersion of the present invention is made from natural plant raw materials such as wood, bamboo, hemp, jute, kenaf, cotton, beet, agricultural waste, and cloth. Examples of the pulp obtained include regenerated cellulose fibers such as rayon and cellophane. Among these, pulp and fibrillated cellulose obtained by fibrillating pulp are preferable raw materials.

  The pulp includes chemical pulp (kraft pulp (KP), sulfite pulp (SP)), semi-chemical pulp (SCP) obtained by pulping plant raw materials chemically or mechanically, or a combination of both. ), Chemi-Grand Pulp (CGP), Chemi-Mechanical Pulp (CMP), Groundwood Pulp (GP), Refiner Mechanical Pulp (RMP), Thermo-Mechanical Pulp (TMP), Chemi-thermo-Mechanical Pulp (CTMP), and these pulps Preferred examples include deinked waste paper pulp, corrugated waste paper pulp and magazine waste paper pulp as components. These raw materials can be delignified or bleached as necessary to adjust the amount of lignin in the pulp.

  Among these pulps, various kraft pulps derived from conifers with strong fiber strength (coniferous unbleached kraft pulps (hereinafter sometimes referred to as NUKP), softwood oxygen-bleached unbleached kraft pulps (hereinafter sometimes referred to as NOKPs), Softwood bleached kraft pulp (hereinafter sometimes referred to as NBKP)) is particularly preferred.

  Pulp is mainly composed of cellulose, hemicellulose, and lignin, and has a structure composed of lignin and hemicellulose that is embedded between cellulose fibers, and part or all of the periphery of the cellulose microfibril bundle is hemicellulose and / or lignin. Has a coated structure. The lignin content in the pulp is not particularly limited, but is usually about 0 to 40% by mass, preferably about 0 to 10% by mass. The lignin content can be measured by the Klason method.

  In the plant cell wall, cellulose microfibrils (single cellulose nanofibers) having a width of about 4 nm are present as a minimum unit. This is the basic skeletal material (basic element) of plants. The cellulose microfibrils gather to form a plant skeleton.

  In the present invention, “cellulose nanofiber (CNF)” is a material (pulverized) obtained by unraveling a fiber-containing material to a nanosize level.

  As a method for defibrating the pulp, a known method can be employed, for example, a water suspension or slurry of the cellulose fiber-containing material is mechanically refined, a high-pressure homogenizer, a grinder, a uniaxial or multiaxial kneader, a bead mill or the like. A method of defibration by grinding or beating can be used. You may process combining the said defibrating method as needed. As a specific defibrating method, for example, a method described in JP 2008-297364 A can be used.

As a specific surface area of a cellulose nanofiber, about 70-300 m < ² > / g is preferable, About 70-250 m < ² > / g is more preferable, About 70-200 m < ² > / g is still more preferable. From the viewpoint of improving the strength of the resin composition prepared using the dispersion liquid, it is preferable that the specific surface area of the cellulose nanofiber is high.

  The average diameter of the cellulose nanofibers is usually about 4 to 200 nm, preferably about 4 to 150 nm, and particularly preferably about 4 to 100 nm. In addition, the average value (average fiber diameter) of the fiber diameter of a cellulose nanofiber is an average value when it measures about at least 50 or more of the modified cellulose nanofiber in the visual field of an electron microscope.

  In the present invention, the cellulose nanofiber (A) may be dyed.

  In the present invention, by using the dyed cellulose nanofiber (A1), a resin composition colored from the dispersion can be prepared. In the present invention, since the nonionic surfactant (B) having an HLB value of 8 to 13 described later is blended in the dispersion, the dispersibility of the dyed (colored) cellulose nanofibers in the dispersion is improved. Thus, it is possible to prepare a resin composition colored with a material having no unevenness in dyeing. Moreover, since cellulose nanofibers are dyed, it is also possible to adjust the density of the dyeing at the material level.

  A method for dyeing cellulose nanofibers is not particularly specified, and a general method for dyeing cellulose fibers can be applied. For example, it can be dyed using reactive dyes, vat dyes (vat dyes), direct dyes, sulfur dyes, naphthol dyes and the like. Of these, reactive dyes and vat dyes are preferably used from the viewpoint of fastness of the dyed article, and reactive dyes are used from the viewpoint of various hue expressions such as the vividness of the dyed article and the color selection range. Is preferred.

  Examples of a method for dyeing cellulose nanofibers using a reactive dye include a method in which a dye is covalently bonded to a hydroxyl group of cellulose nanofibers. As a method of covalently bonding a dye to a hydroxyl group of cellulose nanofiber, a reactive dye having a reactive group such as sulfate ethylsulfonic acid or monochlorotriazine is covalently bonded to the hydroxyl group of cellulose nanofiber to dye the cellulose nanofiber. There is a way to do it. Such reactive dyes include vinyl sulfone reactive dyes, s-triazine reactive dyes, pyrimidine reactive dyes, and the like. Moreover, you may use the reactive dye which has the said functional group with the same kind or different kind and two or more. In dyeing, a reactive dye can be selected depending on the reaction temperature, the equipment for controlling the reaction temperature, the target color, fastness, and the like.

  A dyeing method using a reactive dye will be described. Dyeing with a reactive dye is performed through an absorption process and a fixing process. First, a neutral salt (for example, sodium sulfate) is added to the dye bath, and the dye is diffused into the fiber and adsorbed (absorption treatment). Next, a salt such as sodium carbonate is added to make the dye bath alkaline, and the fibers and the dye are reacted and fixed (covalently bonded) (fixing treatment).

  A dyeing method using a vat dye (a vat dye) will be described. The vat dye does not dissolve in water, but is reduced by a hot liquid (alkaline reducing liquid) of hydrosulfite and sodium hydroxide to be dissolved as a leuco compound. The dissolved vat dye can be dyed onto the fiber in the form of a leuco compound, and then returned to the original vat dye by air oxidation (or oxidation with an oxidizing agent) and allowed to develop color on the fiber. Some of the vat dyes are classified into an indigo type and an anthraquinone type in terms of chemical structure.

  Moreover, as a method of ion-bonding the dye to the hydroxyl group of cellulose nanofiber, there is a method of adsorbing the dye by cationizing cellulose nanofiber, for example, reacting a quaternary ammonium compound to the hydroxyl group of cellulose nanofiber, Thereafter, a dye having an anionic functional group such as a sulfone group can be adsorbed by ionic bond. Examples of the dye having a sulfone group include a direct dye and an acid dye in addition to the reactive dye.

  The amount of the reactive dye used is appropriately set according to the type and purpose of the reactive dye. For example, about 0.01 to 20 parts by mass is preferable with respect to 100 parts by mass of the cellulose nanofiber (A). About 1 to 15 parts by mass is more preferable.

  The content ratio of the cellulose nanofiber (A) in the dispersion is sufficient because the reinforcing effect when the resin composition is obtained can be sufficiently obtained, and because the dispersion can be uniformly dispersed in the dispersion medium. About 0.01 to 5% by mass, more preferably about 0.05 to 3% by mass, and still more preferably about 0.1 to 2% by mass. Moreover, content with respect to the thermoplastic resin (B) of a cellulose nanofiber (A) may be contained about 0.01-300 mass parts with respect to 100 mass parts of thermoplastic resins (B) from the said same reason. Preferably, about 0.1 to 100 parts by mass are contained, and more preferably about 1 to 50 parts by mass.

Thermoplastic resin (B)
The thermoplastic resin (B) includes polyethylene (PE), polypropylene (PP), polyvinyl chloride, polystyrene, polyvinylidene chloride, fluororesin, polymethyl methacrylate, polyamide (PA, nylon), polyester, polycarbonate, polyphenylene oxide. And cellulose resins such as thermoplastic polyurethane, polyacetal, nylon resin, vinyl ether resin, polysulfone resin, triacetylated cellulose, and diacetylated cellulose. These thermoplastic resins may be used alone or as a mixed resin of two or more. Among the thermoplastic resins, polyolefins such as polypropylene, polyethylene, polybutene, and polystyrene, polyamides, for the reason that a sufficient reinforcing effect can be obtained when a resin composition is used, and because they can be uniformly dispersed in a dispersion medium. Is preferred.

  The average particle size of the thermoplastic resin (B) dispersed in the dispersion medium is a resin composition in which a uniform dispersion with cellulose nanofibers can be prepared, and the cellulose nanofibers are uniformly dispersed in the thermoplastic resin. From the reason that a product and a molded object can be produced, about 0.1-500 micrometers is preferable, about 0.2-300 micrometers is more preferable, and about 0.5-100 micrometers is still more preferable.

  As the content ratio of the thermoplastic resin (B), in the dispersion liquid, it is possible to obtain a sufficient reinforcing effect in the case of the resin composition and because it can be uniformly dispersed in the dispersion medium. The content is preferably about 1 to 50% by mass, more preferably about 1 to 40% by mass, and still more preferably about 2 to 30% by mass.

  In the present invention, nonionic surfactants having an HLB value of 8 to 13 described later even in resins such as polypropylene, polyethylene, and polyamide that do not exhibit good dispersibility with respect to a dispersion medium containing water (aqueous dispersion medium). By using (C), good dispersibility can be shown with respect to the dispersion medium containing water.

Nonionic surfactant (C) whose HLB value is 8-13
In the dispersion liquid of the present invention, since the cellulose nanofiber (A) and the thermoplastic resin (B) are present in the dispersion medium (D) described later, the cellulose nanofiber (A) and the thermoplastic resin (B ), A nonionic surfactant (C) that can improve dispersibility is used.

  The reason why the dispersion of the present invention can improve the dispersibility of both the cellulose nanofiber (A) and the thermoplastic resin (B) among the surfactants. For the reason that the strength of the resin composition produced using the resin composition is improved, the resin composition produced using the dispersion liquid containing the dyed cellulose nanofiber (A1) is colored without unevenness in the dyeing. In particular, the nonionic surfactant (C) having an HLB value of 8 to 13 is used because the resin composition can be prepared. Furthermore, the HLB value of the nonionic surfactant is preferably about 8.5 to 12.5, more preferably about 9 to 12, and still more preferably around 11. The HLB value is a value indicating the balance between the hydrophobicity and hydrophilicity of the surfactant. The value is from 1 to 20, and the smaller the numerical value, the stronger the hydrophobicity, and the higher the numerical value, the stronger the hydrophilicity. It shows that.

In the present invention, the HLB value can be obtained from the following Griffin method. In the following threshold, “total formula weight / molecular weight of the hydrophilic portion” is mass% of the hydrophilic group.
Griffin method: HLB value = 20 × (sum of formula weight of hydrophilic group / molecular weight)

  Examples of nonionic surfactants (nonionic surfactants) include ester types, ether types, ester ether types, alkanolamide types, alkylglycosides, and higher alcohols.

The ester type is represented by (RCOO (CH ₂ CH ₂ O) _n H). Specifically, glycerin fatty acid esters (RCOOCH) such as glyceryl laurate (C ₁₁ H ₂₃ COOCH ₂ CH (OH) CH ₂ OH) and glyceryl monostearate (C ₁₇ H ₃₅ COOCH ₂ CH (OH) CH ₂ OH) ₂ CH (OH) CH ₂ OH); sorbitan fatty acid ester (RCOOCH ₂ CH (CHOH) ₃ CH ₂ O, sorbitan laurate); sucrose fatty acid ester (RCOOC ₁₂ H ₂₁ O ₁₀ ) and the like.

The ether type is represented by (RO (CH ₂ CH ₂ O) _n H). R represents a hydrophobic group (lipophilic group). When R is an alkyl group, it becomes a polyoxyethylene alkyl ether, and when R is an alkylbenzene, it becomes a polyoxyethylene alkyl phenolate. Specifically, pentaethylene glycol monododecyl ether (C ₁₂ H ₂₅ O (CH ₂ CH ₂ O) ₅ H), octaethylene glycol monododecyl ether (C ₁₂ H ₂₅ O (CH ₂ CH ₂ O) ₈ H) fatty alcohol ethoxylate of equal (polyoxyethylene alkyl _{ethers, RO (CH 2 CH 2 O} ) nH); nonoxynol _{(C 9 H 19 C 6 H} 4 O (CH 2 CH 2 O) n H, nonylphenol ethoxylate), Polyoxyethylene alkyl phenyl ethers (RC ₆ H ₄ O (CH ₂ CH ₂ O) _n H) such as nonoxynol-9 (C ₉ H ₁₉ C ₆ H ₄ O (CH ₂ CH ₂ O) ₉ H); polyoxy And ethylene polyoxypropylene glycol (H (OCH ₂ CH ₂ ) _l (OC ₃ H ₆ ) _m (OCH ₂ CH ₂ ) _n OH).

  Examples of the ester ether type include polyoxyethylene sorbitan fatty acid ester, polyoxyethylene hexitan fatty acid ester, sorbitan fatty acid ester polyethylene glycol and the like.

The alkanolamide type, lauric acid diethanolamide _{(C 11 H 23 CON (C} 2 H 4 OH) 2), oleic acid diethanolamide _{(C 17 H 33 CON (C} 2 H 4 OH) 2), stearic acid diethanolamide _{(C 17 H 35 CON (C} 2 H 4 OH) 2), cocamide _{DEA (CH 3 (CH 2)} nCON (C 2 H 4 OH) 2) , and the like.

Alkyl glycosides (RC ₆ H ₁₁ O ₆ ) include octyl glucoside (C ₈ H ₁₇ C ₆ H ₁₁ O ₆ ), decyl glucoside (C ₁₀ H ₂₁ C ₆ H ₁₁ O ₆ ), lauryl glucoside (C ₁₂ H ₂₅ C ₆ H ₁₁ O ₆ ) and the like.

Examples of higher alcohols include cetanol (C ₁₆ H ₃₃ OH), stearyl alcohol (C ₁₈ H ₃₇ OH), oleyl alcohol (CH ₃ (CH ₂ ) ₇ CH═CH (CH ₂ ) ₈ OH), and the like.

For example, when polyoxyethylene nonylphenyl ether (C ₉ H ₁₉ C ₆ H ₄ O (CH ₂ CH ₂ O) _n H) is used, the number of moles (n number) of polyoxyethylene is about 4 to 9 Preferably, about 5-8 is more preferable, and 7 vicinity is still more preferable. As such polyoxyethylene nonylphenyl ether, nonipol (polyoxyethylene nonylphenyl ether) manufactured by Sanyo Chemical Industries, Ltd. can be used. For example, nonipol 40 (HLB value: 8.0, polyoxyethylene) 4), nonipol 70 (HLB value: 11.7, polyoxyethylene mole number: 7), nonipol 85 (HLB value: 12.6, polyoxyethylene mole number: 8-9) are preferred. Can be used. In particular, by using Nonipol 70 (HLB value: 11.7, number of moles of polyoxyethylene: 7), both cellulose nanofiber (A) and thermoplastic resin (B) (for example, polypropylene, polypropylene, polyamide, etc.) On the other hand, dispersibility can be improved.

  In the present invention, the HLB value of the nonionic surfactant (C) may be 8 to 13, and two or more nonionic surfactants may be mixed to adjust the HLB value. For example, a sorbitan ester type nonionic surfactant (trade name: SPAN80, sorbitan monooleate) and polyoxyethylene sorbitan monooleate (trade name: TWEEN80) in which ethylene oxide is added to the same active agent are mixed, and HLB is mixed. It is possible to adjust the value to 8-13.

  As the content of the nonionic surfactant (C), the cellulose nanofiber (A) and the thermoplastic resin (B) described above can be favorably dispersed in the dispersion medium (D) described later. The dispersion preferably contains about 0.01 to 10% by mass, more preferably about 0.05 to 5% by mass, and further preferably about 0.1 to 3% by mass. For the same reason, the addition amount of the nonionic surfactant (C) is about 0.1 to 100 parts by mass with respect to 100 parts by mass of the total amount of the cellulose nanofiber (A) and the thermoplastic resin (B). Is preferable, about 0.5-50 mass parts is more preferable, and about 1-30 mass parts is still more preferable.

  In addition to the nonionic surfactant used in the present invention, examples of the surfactant include an anionic surfactant and a cationic surfactant. These anionic surfactants and cationic surfactants may be appropriately contained as long as the effects of the present invention are not impaired. However, the anionic surfactant is adsorbed when the cationized cellulose nanofiber is used, and the cationic surfactant is adsorbed with the cellulose nanofiber (A) alone. It is not preferable to use in the above.

Dispersion medium (D)
The dispersion of the present invention is dispersible with respect to both the cellulose nanofiber (A) and the thermoplastic resin (B) in the presence of a nonionic surfactant (C) having an HLB value of 8 to 13. A dispersion medium (D) that can improve the viscosity can be used.

  The dispersion medium (D) can be an aqueous dispersion medium (D1) containing water because cellulose nanofibers having high hydrophilicity can be favorably dispersed in the dispersion. When an aqueous dispersion medium containing water is used, an aqueous dispersion containing cellulose nanofiber (A), a thermoplastic resin (B), a nonionic surfactant (C) having an HLB value of 8 to 13 and the like is obtained.

  Further, for the reason that the dispersibility of the cellulose nanofiber (A) and the thermoplastic resin (B) can be improved, a hydrophilic organic solvent such as a lower alcohol having compatibility with water may be used in combination. Examples of lower alcohols include alcohols having 1 to 7 carbon atoms such as methyl alcohol, ethyl alcohol, n-propyl alcohol, isopropyl alcohol, 1,3-butyl alcohol, sec-butyl alcohol, isobutyl alcohol, tert-butyl alcohol, and benzyl alcohol. A polyhydric alcohol having 2 to 5 carbon atoms such as glycerin, isopropylene glycol, propylene glycol, and 1,3-butylene glycol can be exemplified. Examples of other hydrophilic organic solvents include methyl acetate, ethyl acetate, acetone, methyl acetoacetate and the like. As the dispersion medium (D), only water may be used, or a solvent other than one kind or two or more kinds of water may be used in combination as a mixed solvent.

  Improve the affinity between the cellulose nanofiber (A) and the thermoplastic resin (B) and the dispersion medium (D), and improve the dispersibility with respect to both the cellulose nanofiber (A) and the thermoplastic resin (B). For this purpose, a binder such as a water-soluble polymer may be added to the dispersion medium (D). Water-soluble polymers include starches, mannans, seaweeds such as galactan and sodium alginate, plant mucilage such as gum tragacanth, gum arabic and dextran, proteins such as gelatin and casein, and celluloses such as methylcellulose, hydroxycellulose and carboxymethylcellulose. , Synthetic polymers such as polyvinyl alcohol, sodium polyacrylate, polyethylene oxide, polyvinyl pyrrolidone, and polyacrylamide.

Other ingredients (E)
In addition to the components contained in the dispersion, for example, compatibilizers; surfactants (other than the above); polysaccharides such as starches and alginic acid; natural proteins such as gelatin, glue and casein; tannins and zeolites Additives such as inorganic compounds such as ceramics, metal powders, colorants, plasticizers, fragrances, pigments, flow regulators, leveling agents, conductive agents, antistatic agents, ultraviolet absorbers, ultraviolet dispersants, and deodorants You may mix | blend. As a content ratio of an arbitrary additive, it may be appropriately contained within a range not impairing the effects of the present invention.

  The pH of the dispersion may be practically in the range of about 4 to 11, and more preferably in the range of 6 to 8. The pH can be adjusted using a basic substance or an acidic substance. Examples of the basic substance include inorganic bases such as sodium hydroxide and potassium hydroxide; organic amines such as triethanolamine and diisopropanolamine; basic amino acids such as arginine, lysine and ornithine. Examples of acidic substances include inorganic acids and organic acids such as hydrochloric acid, nitric acid, metasulfonic acid, sulfuric acid, p-toluenesulfonic acid, phosphoric acid, citric acid, malic acid, tartaric acid, and succinic acid.

<Resin composition>
The resin composition of the present invention contains a dyed cellulose nanofiber (A1) and a thermoplastic resin (B).

  The dyed cellulose nanofiber (A1) is obtained by dyeing cellulose nanofiber (A) with a reactive dye or the like as described in <Dispersion>. The resin composition of the present invention can prepare a colored resin composition by using dyed cellulose nanofibers.

  As the thermoplastic resin (B), the same resin as described in <Dispersion> can be used.

  In the resin composition, the content ratio of the dyed cellulose nanofiber (A1) is because the reinforcing effect when the resin composition is obtained can be sufficiently obtained, and the resin composition can be uniformly colored. It is preferable that about 0.01 to 300 parts by mass is included with respect to 100 parts by mass of the thermoplastic resin (B), more preferably about 0.1 to 100 parts by mass, and about 1 to 50 parts by mass. More preferably.

  As described in <Dispersion>, the resin composition of the present invention has a dyed cellulose nanofiber (A1), a thermoplastic resin (B), and an HLB value of 8 to 13 in the dispersion medium (D). It is prepared from a dispersion containing the nonionic surfactant (C). The nonionic surfactant (C) whose HLB value is 8-13 may be contained in the resin composition of the present invention.

<Method for producing dispersion and resin composition>
The dispersion liquid of the present invention is prepared by mixing the cellulose nanofiber (A), the thermoplastic resin (B), and the nonionic surfactant (C) having an HLB value of 8 to 13 in the dispersion medium (D). can do. As a result, a dispersion liquid in which the cellulose nanofibers (A) and the thermoplastic resin (B) are uniformly dispersed in the dispersion medium (D) can be obtained. You may use the dyed cellulose nanofiber (A1) as a cellulose nanofiber (A).

  Each concentration of cellulose nanofiber (A), thermoplastic resin (B) and nonionic surfactant (C) in the dispersion is such that the final concentration in the dispersion is the concentration described in <Dispersion>. Adjust to. For example, in the dispersion medium (D), cellulose nanofiber (A): about 0.1 to 2% by mass, thermoplastic resin (B): about 2 to 30% by mass, nonionic surfactant (C): 0. It is preferable that about 1-5 mass% is contained.

  Although it does not specifically limit as a method of mixing a cellulose nanofiber (A), a thermoplastic resin (B), a nonionic surfactant (C), and a dispersion medium (D), What is necessary is just to perform stirring etc. In the stirring, a planetary stirrer, an ultrasonic homogenizer, a propeller stirrer, or the like can be used, but is not limited thereto. The stirring time for dispersing is not particularly limited, and can be appropriately set according to the degree of dispersion of the cellulose nanofiber (A) and the thermoplastic resin (B). Moreover, the method of mixing and stirring with apparatuses which can mix or stir, such as a mixer, a blender, a twin-screw kneader, a kneader, a lab plast mill, a homogenizer, a high-speed homogenizer, a high-pressure homogenizer, a planetary stirring apparatus, and a three-roll apparatus.

  The mixing temperature is preferably about 5 to 40 ° C., more preferably about 10 to 30 ° C., because the cellulose nanofiber (A) and the thermoplastic resin (B) can be uniformly mixed.

  Moreover, you may mix | blend and mix other components (E) arbitrarily.

  Since the dispersion containing the cellulose nanofiber (A) and the thermoplastic resin (B) of the present invention contains a nonionic surfactant (C) having an HLB value of 8 to 13, the cellulose nanofiber in the dispersion medium In addition, the dispersibility of the thermoplastic resin can be improved.

  The dispersion liquid of the present invention is obtained by simultaneously mixing the cellulose nanofiber (A), the thermoplastic resin (B), and the nonionic surfactant (C) having an HLB value of 8 to 13 in the dispersion medium (D). It may be prepared.

The dispersion of the present invention is
(1) A step of adding cellulose nanofiber (A) and thermoplastic resin (B) to dispersion medium (D), and (2) a nonionic surfactant (C) having an HLB value of 8 to 13 is added. It is preferable to manufacture by the preparation method which has a process in order.

  After adding the cellulose nanofiber (A) and the thermoplastic resin (B) in the dispersion medium (D), the nonionic surfactant (C) having an HLB value of 8 to 13 is added and mixed to disperse. In the medium (D), the cellulose nanofiber (A) and the thermoplastic resin (B) can be favorably dispersed.

  The resin composition of the present invention contains a dyed cellulose nanofiber (A1) and a thermoplastic resin (B), and is obtained from the dispersion.

The resin composition of the present invention is
(1) a step of dyeing cellulose nanofiber (A),
(2) In the dispersion medium (D), the cellulose nanofiber (A1) dyed in Step 1, the thermoplastic resin (B), and the nonionic surfactant (C) having an HLB value of 8 to 13 are mixed, It can be produced by a production method comprising a step of preparing a dispersion and (3) a step of removing the dispersion medium from the dispersion.

  As a dyeing method of the cellulose nanofiber (A) in step 1, as described in the above <Dispersion>, the cellulose nanofiber (A) can be dyed using a reactive dye or the like.

  As a mixing method in Step 2, as described above, in the dispersion medium (D), the dyed cellulose nanofiber (A1), the thermoplastic resin (B), and the nonionic surfactant having an HLB value of 8 to 13 (C) can be mixed, for example with a mixer etc., and a dispersion liquid can be obtained. At this time, in the step of preparing the dispersion, in the dispersion medium (D), the cellulose nanofiber (A) and the thermoplastic resin (B) can be favorably dispersed in the dispersion medium (D). After adding the cellulose nanofiber (A) and the thermoplastic resin (B), a nonionic surfactant (C) having an HLB value of 8 to 13 is preferably added and mixed.

  Examples of the method for removing the dispersion medium from the dispersion in Step 3 include suction filtration, dehydration, and drying. When suction filtration is performed, forcibly dehydrated by passing acetone through for the reason that separation / aggregation of the cellulose nanofiber (A) and the thermoplastic resin (B) can be prevented. By removing this dispersion medium, the nonionic surfactant (C) having an HLB value of 8 to 13 can also be removed, but the nonionic surfactant (C) may be present in the resin composition.

  After preparing the dispersion liquid of the present invention by the production method of the present invention, the dispersion medium (D) is removed, whereby the dyed cellulose nanofibers (A1) and the thermoplastic resin (B) are uniformly dispersed. A resin composition can be obtained.

  In the resin composition of the present invention, since the cellulose nanofibers are uniformly dispersed in the thermoplastic resin, when a molding material and a molded body are produced from the resin composition, the reinforcing effect of the cellulose nanofibers can be expressed, Mechanical strength such as bending strength and tensile strength can be increased.

<Molding material and molded body>
The present invention also relates to a molding material using the resin composition and a molded body obtained by molding the molding material.

  The resin composition can be molded into a desired shape and used as a molding material. Examples of the shape of the molding material include sheets, pellets, and powders. The molding material having these shapes can be obtained by using, for example, mold molding, injection molding, extrusion molding, hollow molding, foam molding and the like.

  The molding conditions may be applied by appropriately adjusting the molding conditions of the resin, such as a press, as necessary. The molded body can be used not only in the field of fiber reinforced plastics where cellulose nanofiber-containing resin moldings have been used, but also in fields where higher mechanical strength (such as tensile strength) is required. For example, interior materials, exterior materials, structural materials, etc. for transportation equipment such as automobiles, trains, ships, airplanes, etc .; housings, structural materials, internal parts, etc. for electrical appliances such as personal computers, televisions, telephones, watches, etc .; mobile phones, etc. Housing, structural materials, internal parts, etc. for mobile communication equipment; portable music playback equipment, video playback equipment, printing equipment, copying equipment, housing for sports equipment, etc .; construction materials, office equipment such as stationery It can be used effectively as a container, a container, etc.

  Since the dispersion containing the cellulose nanofiber and the thermoplastic resin of the present invention contains a nonionic surfactant having an HLB value of 8 to 13, the dispersibility of the cellulose nanofiber and the thermoplastic resin in the dispersion medium is improved. Can be made.

It is a photograph showing the dispersion state of the dyed cellulose nanofiber and the thermoplastic resin in the resin composition obtained in Test Example 2. It is a figure of the X-ray CT observation showing the dispersion state of the dyed cellulose nanofiber and the thermoplastic resin in the resin composition obtained by Test Example 2. It is a photograph showing the dispersion state of the dyed cellulose nanofiber and the thermoplastic resin in the resin composition obtained in Test Example 3. It is a photograph showing the dispersion | distribution state of the dyed cellulose nanofiber and the thermoplastic resin in the resin composition obtained by Test Example 4, Test Example 5, and the reference example. It is a figure of the X-ray CT observation showing the dispersion | distribution state of the dyed cellulose nanofiber and the thermoplastic resin in the resin composition obtained by the test example 4, the test example 5, and the reference example.

<Example>
EXAMPLES Hereinafter, although an Example and a comparative example are given and this invention is demonstrated further in detail, this invention is not limited to these.

<Dispersion material>
Cellulose nanofiber (A): 600 g of softwood bleached kraft pulp (refiner-treated, manufactured by Oji Paper Co., Ltd., solid content 25%) and 19.94 kg of water were added to prepare an aqueous suspension (pulp slurry concentration) 0.75 wt% aqueous suspension). The obtained slurry was mechanically treated with a bead mill (NVM-2, manufactured by Imex Co., Ltd.). The treatment conditions were as follows: zirconia beads (diameter: 1 mm) with a bead filling rate of 70% (4043 g), spindle rotation speed of 2500 rpm, vessel temperature of 20 ° C., residence time of 2.5 minutes, and treatment frequency of 2 times. The specific surface area of the cellulose nanofiber is 138 m ² / g, and the average value of the fiber diameter of the cellulose nanofiber is 35 nm.

Cellulose nanofiber dyeing method Using reactive dye (Sumifix Supra Brilliant Red 3BF 150% gran manufactured by Sumitomo Chemical Co., Ltd.), anhydrous sodium sulfate and anhydrous sodium carbonate were added as dyeing assistants, and cellulose nanofiber was dyed at 60 ° C. Stained cellulose nanofibers (stained CNF) were prepared.

-Thermoplastic resin (B): Nippon Polypro Co., Ltd. product name “MA4AHB” (polypropylene resin, PP) (average particle diameter of PP: 17 μm) was used. Maleic acid-modified polypropylene (MAPP, manufactured by Toyo Kasei Kogyo Co., Ltd .: trade name “Toyotac H1000P”) was used.

Nonionic surfactant (C) having an HLB value of 8 to 13: Nonipol 40 (HLB value: 8.0, polyoxyethylene) produced by Sanyo Chemical Industries, Ltd. Nonipol (polyoxyethylene nonylphenyl ether) Number of moles: 4), Nonipol 70 (HLB value: 11.7, number of moles of polyoxyethylene: 7), Nonipol 85 (HLB value: 12.6, number of moles of polyoxyethylene: 8 to 9) were used. (a n = 4 to 9 is in the _{C 9 H 19 C 6 H 4} O (CH 2 CH 2 O) n H).
As nonionic surfactants other than the above, Nonipol 100 (HLB value: 13.3), Nonipol 160 (HLB value: 15.2), which are nonipol (polyoxyethylene nonylphenyl ether) manufactured by Sanyo Chemical Industries, Ltd. Using.

-Dispersion medium (D): Water and ethanol were used.

<Preparation of dispersion>
In various dispersion media, dyed cellulose nanofiber (dyed CNF), polypropylene resin (PP), and various nonionic surfactants were mixed with a lab plast mill to prepare a dispersion.

The evaluation criteria of the dispersion state of dyed CNF and PP are as follows.
A: CNF or PP is sufficiently dispersed in the dispersion medium in the dispersion even after 12 hours have passed after stirring at 20 ° C. and a humidity of 50%.
○: After stirring, after 1 hour at 20 ° C. and 50% humidity, an interface is formed between the dispersion medium and CNF or PP in the dispersion, and layer separation is possible, but there is no problem in practice. .
Δ: After stirring, after 30 minutes under the conditions of 20 ° C. and 50% humidity, an interface is formed between the dispersion medium and CNF or PP in the dispersion, and layer separation is possible, but there is no problem in practice. .
X: After stirring, immediately after stirring under the conditions of 20 ° C. and humidity 50%, an interface is formed between the dispersion medium and CNF or PP in the dispersion, and layer separation can be performed, which cannot be performed.

(1) Dispersibility of dyed CNF and PP by addition of nonionic surfactant
(1-1) Dispersibility of dyed CNF by addition of nonionic surfactant To each 0.05 mass% aqueous suspension of dyed CNF, various nonionic surfactants are added (2% by mass in the dispersion). The dispersibility of the dyed CNF was observed (water was used as the dispersion medium).

  The results are shown in Table 1 below.

  According to Table 1, the dispersibility of the dyed CNF was improved by adding a nonionic surfactant having an HLB value of 8 to 13 to the dispersion medium.

(1-2) Dispersibility of PP by addition of nonionic surfactant To each 0.5% by mass aqueous suspension of PP, various nonionic surfactants were added (2% by mass in the dispersion). Was observed (water was used as a dispersion medium).

  The results are shown in Table 2 below.

  From Table 2, the dispersibility of PP was improved by adding a nonionic surfactant having an HLB value of 8 to 13 to the dispersion medium.

(1-3) Dispersibility of CNF and PP by addition of nonionic surfactant
Test example 1:
Various nonionic surfactants were added to the aqueous suspension containing dyed CNF (0.05% by mass in the dispersion) and PP (0.5% by mass in the dispersion) (2% by mass in the dispersion). The dispersibility of the dyed CNF and PP was observed (water was used as the dispersion medium).

  The results are shown in Table 3 below.

  From Table 3, the dispersibility of dyeing | staining CNF and PP improved by adding the nonionic surfactant whose HLB value is 8-13 in a dispersion medium.

Test example 2:
Nonipol 70 (HLB value: 11.7, number of moles of polyoxyethylene: 7) was added to an aqueous suspension of dyed CNF so as to be 3% by mass and 1% by mass with respect to the whole dispersion, and then PP. (MAPP included) was added and mixed with a homomixer to obtain a dispersion containing dyed CNF and PP (in the dispersion, dyed CNF: 1% by mass, PP (including MAPP): 9% by mass). Next, the dispersion containing dyed CNF and PP was suction filtered, and dried while passing acetone (dehydrating) to obtain a resin composition containing dyed CNF and PP. Next, a 0.5 mm spacer was placed and the resin composition was pressed to form a molded body.

  The results of Test Example 2 are shown in FIGS.

The measurement conditions of X-ray CT (X-ray tomography) are described below.
・ Device: SKYSCAN1172 version 1.5 made by Skyscan (Belgium)
-Image reconstruction software: Skyscan's NRecon
・ Measurement conditions ・ Spatial resolution: 0.7μm, analysis area: 590 × 590 × 210μm
・ Explanation of the photo ・ Square image (analysis area viewed from above): 590 × 590μm
・ Rectangular image (image of the analysis area seen from the side): 590 × 210μm
・ 3D image: 590 × 590 × 210μm
・ Tube voltage: 60kV, tube current: 100μA, no filter ・ Number of projections: 1800 (taken 180 degrees in 0.1 ° increments)

Test Example 3:
Nonipol 70 is added to the aqueous suspension of dyed CNF so as to be 3% by mass and 1% by mass with respect to the whole dispersion, and then PP (including MAPP) is added and mixed with a homomixer. A dispersion containing dyed CNF and PP was obtained (in the dispersion, dyed CNF: 1% by mass, PP (including MAPP): 9% by mass). Next, the dispersion containing dyed CNF and PP was suction filtered, and dried while passing acetone (dehydrating) to obtain a resin composition containing dyed CNF and PP. Next, without placing a spacer, the resin composition was subjected to high compression pressing to prepare a molded body.

  The results of Test Example 3 are shown in FIG.

  1 to 3, a dispersion liquid is prepared by adding a nonionic surfactant having an HLB value of 8 to 13 to a dispersion medium containing dyed CNF and PP, and a resin composition prepared from the dispersion liquid, and In the molded product, it was possible to prepare a resin composition and molded product colored with a material having good dispersibility of dyed CNF in the resin component (PP) and no unevenness in dyeing.

  A physical property test (tensile test) was performed on the molded body (nonipol 70 1 mass%, nonipol 70 3 mass%) prepared in Test Example 2. The physical property test conditions were: sample shape: flat plate (width: approx. 5 mm, thickness: approx. 0.4 mm), chuck distance: 25 mm, tensile speed: 1 mm / min, load cell: 1 kN, maximum point stress (average of 5 points) ) Was measured.

  As a result, in the dispersion medium containing the dyed CNF and PP, a nonionic surfactant having an HLB value of 8 to 13 was added to prepare a dispersion, and the resin composition and the molded body prepared from the dispersion were: Compared to a resin composition and a molded article prepared without adding a nonionic surfactant, the tensile strength was equal to or higher than that of the molded article, and the physical properties were also good.

(2) Dispersibility of dyed CNF and PP by adding ethanol
(2-1) Dispersibility of dyed CNF by adding ethanol In mixed dispersion medium (10 ml) containing water and ethanol (EtOH), the dispersibility of dyed CNF was examined by changing the ethanol content (dispersion). Dyeing CNF in liquid: 0.05% by mass). The results are shown in Table 4 below.

  According to Table 4, in the mixed dispersion medium containing water and ethanol, the dispersibility of the dyed CNF was improved when the content ratio of ethanol was 60% by mass or less.

(2-2) Dispersibility of PP by adding ethanol Dispersibility of PP was observed in a mixed dispersion medium (5 ml) containing water and ethanol (EtOH) by changing the ethanol content (in the dispersion). PP: 2% by mass). The results are shown in Table 5 below.

  According to Table 5, in the mixed dispersion medium containing water and ethanol, the dispersibility of PP was improved when the content ratio of ethanol was 50 to 70% by mass.

(2-3) Effect of added amount of ethanol on CNF and PP aqueous dispersion
Test Example 4:
Add ethanol (same amount as the aqueous suspension of stained CNF) to the aqueous suspension of stained CNF (stained CNF: 1% by mass), then add PP (including MAPP) and mix with a homomixer. Thus, a dispersion containing dyed CNF and PP was obtained (in the dispersion, dyed CNF: 0.05% by mass, PP (including MAPP): 2% by mass). Next, the dispersion containing dyed CNF and PP was suction filtered and dried to obtain a resin composition containing dyed CNF and PP. Next, the resin composition was pressed to form a molded body.

Test Example 5:
Add ethanol (same amount as the aqueous suspension of stained CNF) to the aqueous suspension of stained CNF (stained CNF: 1% by mass), then add PP (including MAPP) and mix with a homomixer. Thus, a dispersion containing dyed CNF and PP was obtained (in the dispersion, dyed CNF: 0.05% by mass, PP (including MAPP): 2% by mass). Next, the dispersion containing dyed CNF and PP was suction filtered, and dried while passing acetone (dehydrating) to obtain a resin composition containing dyed CNF and PP. Next, the resin composition was pressed to form a molded body.

Reference example:
A dispersion containing dyed CNF and PP is obtained by adding PP (including MAPP) at a ratio of 9% by weight to an aqueous suspension of dyed CNF (dyed CNF: 1% by weight) and mixing with a homomixer. It was. Next, the dispersion containing dyed CNF and PP was suction filtered and dried to obtain a resin composition containing dyed CNF and PP. Next, the resin composition was pressed to form a molded body.

  The results of Test Example 4, Test Example 5 and Reference Example are shown in FIGS.

  According to FIGS. 4 and 5, a dispersion containing dyed CNF and PP is prepared using a mixed dispersion medium containing water and ethanol, and in the resin composition prepared from the dispersion, dyeing in the resin component (PP) is performed. It was possible to prepare a colored resin composition having good dispersibility of CNF and no unevenness in dyeing.

<Discussion>
In a dispersion medium containing dyed CNF and PP, a nonionic surfactant having an HLB value of 8 to 13 is added to prepare a dispersion, and in the resin composition prepared from the dispersion, the resin component (PP) It is possible to prepare a colored resin composition having good dispersibility of the dyed CNF and no unevenness in dyeing.

  In addition, a dispersion containing dyed CNF and PP is prepared using a mixed dispersion medium containing water and ethanol, and the resin composition prepared from the dispersion has a dispersibility of the dyed CNF in the resin component (PP). A resin-colored resin composition that is good and has no unevenness in dyeing can be prepared.

Claims (12)

A dispersion comprising cellulose nanofiber (A), a thermoplastic resin (B), and an ether type nonionic surfactant (C) having an HLB value of 8 to 13. The dispersion liquid according to claim 1, wherein the cellulose nanofiber (A) is dyed. The dispersion according to claim 1 or 2, wherein the thermoplastic resin (B) is at least one selected from the group consisting of polypropylene, polyethylene, and polyamide.   The dispersion according to any one of claims 1 to 3, wherein the ether-type nonionic surfactant (C) is at least one selected from the group consisting of polyoxyethylene alkyl ethers and polyoxyethylene alkyl phenolates.   The ether type nonionic surfactant (C) is at least one selected from the group consisting of polyoxyethylene alkyl ether, polyoxyethylene alkylphenyl ether and polyoxyethylene polyoxypropylene glycol. A dispersion according to any one of the above.   The dispersion according to any one of claims 1 to 3, wherein the ether type nonionic surfactant (C) is polyoxyethylene nonylphenyl ether having 4 to 9 moles of polyoxyethylene. It is a resin composition obtained from the dispersion liquid in any one of Claim 1 , 2, and 4-6, Comprising : The said thermoplastic resin (B) is chosen from the group which consists of a polypropylene, polyethylene, polybutene, a polystyrene, and a polyamide. A resin composition which is at least one kind . (1) a step of dyeing cellulose nanofiber (A),
(2) In the dispersion medium (D), the cellulose nanofiber (A1) dyed in Step 1, the thermoplastic resin (B), and the ether type nonionic surfactant (C) having an HLB value of 8 to 13 are mixed. And a step of preparing a dispersion, and (3) a method for producing a resin composition comprising a step of removing a dispersion medium from the dispersion.   The method for producing a resin composition according to claim 8, wherein the dispersion medium (D) is water or an aqueous dispersion medium (D1) containing water.   The method for producing a resin composition according to claim 8 or 9, wherein the dispersion medium (D) is a dispersion medium containing water and a hydrophilic organic solvent. (1) adding cellulose nanofiber (A) and thermoplastic resin (B) to dispersion medium (D), and (2) ether type nonionic surfactant (C) having an HLB value of 8 to 13. The manufacturing method of the dispersion which has the process to add in order. At least one thermoplastic resin (B) selected from the group consisting of cellulose nanofiber (A), polypropylene, polyethylene, polybutene, polystyrene and polyamide, and ether type nonionic surfactant (C) having an HLB value of 8-13 The resin composition obtained from the dispersion liquid containing this .

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