JP2014040535A - Resin composition, molding material, molded body, and method of producing resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a resin composition superior in dispersibility of cellulose fibers.SOLUTION: The resin composition includes a cellulose fiber, and an ethylene-unsaturated carboxylic acid copolymer including ethylene and unsaturated carboxylic acid as copolymerization components or an ionomer resin thereof.

Description

  The present invention relates to a resin composition, a molding material, a molded article obtained by molding the resin composition, and a method for producing the resin composition.

  Natural product-derived materials with low environmental impact are attracting attention. Among natural products, cellulose is produced in large quantities, so it is expected to be used for various functional materials.

Patent Document 1 (Japanese Patent Laid-Open No. 2009-197122) discloses a resin composition containing cellulose fibers and natural and / or synthetic resin emulsion, wherein the cellulose fibers include cellulose fibers having an average fiber diameter of 200 nm or less. The resin composition whose carboxyl group content of the cellulose which comprises the said cellulose fiber is 0.1-2 mmol / g is disclosed.
It is described that when this resin composition is used, a dry film having high strength can be formed.

JP 2009-197122 A

  However, the resin composition described in Patent Document 1 has a problem that the compatibility between the cellulose fiber and the resin is poor, and the cellulose fiber is not uniformly dispersed in the resin. For this reason, in the molded product obtained using such a resin composition, cellulose fibers may be unevenly distributed. If it does so, nonuniformity will arise in physical properties, such as mechanical strength, in a molded object, or the transparency of a molded object will fall.

  Then, this invention makes it a subject to provide the resin composition excellent in the dispersibility of a cellulose fiber.

  The present inventors diligently studied to solve the above problems. As a result, the inventors have found that the use of an ethylene / unsaturated carboxylic acid copolymer or its ionomer resin together with cellulose fibers is effective in improving the dispersibility of cellulose fibers, and the present invention has been achieved.

That is, according to the present invention,
Cellulose fiber,
An ethylene / unsaturated carboxylic acid copolymer or an ionomer resin thereof containing ethylene and an unsaturated carboxylic acid as a copolymerization component;
A resin composition is provided.

Furthermore, according to the present invention,
A molding material containing the resin composition is provided.

Furthermore, according to the present invention,
A molded body obtained by molding the molding material is provided.

Furthermore, according to the present invention,
A dispersion (A) containing cellulose fibers;
A dispersion (B) containing an ethylene / unsaturated carboxylic acid copolymer or an ionomer resin thereof containing ethylene and an unsaturated carboxylic acid as a copolymerization component;
The manufacturing method of the resin composition including the process of mixing is provided.

  ADVANTAGE OF THE INVENTION According to this invention, the resin composition excellent in the dispersibility of a cellulose fiber can be provided.

  Embodiments according to the present invention will be described below.

The resin composition in the present embodiment includes cellulose fibers and an ethylene / unsaturated carboxylic acid copolymer or an ionomer resin thereof containing ethylene and an unsaturated carboxylic acid as a copolymerization component.
The resin composition in this embodiment can improve the dispersibility of the cellulose fiber in the resin composition by including an ethylene / unsaturated carboxylic acid copolymer or its ionomer resin.
In this embodiment, the ionomer resin is obtained by using an ethylene / unsaturated carboxylic acid copolymer as a base polymer and neutralizing a carboxyl group in the ethylene / unsaturated carboxylic acid copolymer with a metal ion. Say.

(Cellulose fiber)
First, the cellulose fiber in this embodiment is demonstrated.

  The cellulose fibers in this embodiment preferably have an average fiber diameter of 1 nm to 100 nm, more preferably 1 nm to 50 nm, and still more preferably 1 nm to 10 nm. When the average fiber diameter of the cellulose fibers is within the above range, the dispersibility of the cellulose fibers in the resin composition can be further improved.

  In addition, the average aspect ratio defined by the ratio of the average fiber length to the average fiber diameter (average fiber length / average fiber diameter) of the cellulose fiber in the present embodiment is preferably 10 or more and 5000 or less. It is preferably 10 or more and 2000 or less, more preferably 10 or more and 1000 or less, and particularly preferably 10 or more and 500 or less. When the average aspect ratio of the cellulose fiber is within the above range, the dispersibility of the cellulose fiber in the resin composition can be further improved.

  Here, the fiber diameter and the fiber length of the cellulose fiber can be measured from the image of the cellulose fiber taken with a microscope such as an atomic force microscope. Moreover, the average fiber diameter and average fiber length of a cellulose fiber can measure the fiber diameter and fiber length of 10 cellulose fibers, respectively, and can employ | adopt the average value.

  As for the cellulose fiber in this embodiment, it is preferable that the cellulose which comprises it is an oxidized cellulose. When the cellulose constituting the cellulose fiber is oxidized cellulose, the dispersibility of the cellulose fiber in the resin composition can be further improved.

  The carboxyl group content of the oxidized cellulose (molar amount of carboxy group contained in 1 g of oxidized cellulose) is preferably 0.1 mmol / g or more and 2 mmol / g or less, more preferably 0.4 mmol / g or more and 2 mmol. / G or less, particularly preferably 0.6 mmol / g or more and 1.8 mmol / g or less. Here, carboxyl group content can be measured by neutralization titration, for example.

When the carboxyl group content is not less than the above lower limit, the viscosity of the dispersion containing cellulose fibers is lowered, and the handling of the dispersion can be improved.
Moreover, since the electrostatic repulsion between fibers becomes strong as carboxyl group content is more than the said lower limit, the dispersibility of a cellulose fiber can be improved in a dispersion. Moreover, the dispersibility in the resin composition of a cellulose fiber can be improved further.
Here, the good dispersibility means that the cellulose fiber hardly causes aggregation or sedimentation in the dispersion. Dispersibility is confirmed by visual observation of the aqueous dispersion.

  When the carboxyl group content is less than or equal to the above upper limit value, the oxidation treatment step during adjustment of oxidized cellulose can be shortened. Moreover, the viscosity of the dispersion containing cellulose fibers is reduced, and the handling of the dispersion can be improved. Furthermore, the water resistance and heat resistance of the obtained molded body can be improved.

  As the oxidized cellulose, those obtained by oxidizing cellulose using an N-oxyl compound such as 2,2,6,6-tetramethylpiperidine-N-oxyl (TEMPO) as an oxidation catalyst are particularly preferable. .

When oxidation treatment is performed using an N-oxyl compound, the primary hydroxyl group (hydroxyl group bonded to the 6-position carbon atom of the glucopyranose ring) in the cellulose molecule is oxidized with high selectivity, and —CH ₂ OH is converted to —CH ₂ OH. It is converted to a carboxy group via a formyl group. According to the oxidation treatment using the N-oxyl compound, carboxy groups can be introduced uniformly and efficiently.
Moreover, the oxidation treatment using an N-oxyl compound is unlikely to impair the crystallinity of cellulose. Therefore, oxidized cellulose microfibrils obtained by oxidation treatment using an N-oxyl compound retain the high crystal structure of natural cellulose and can provide high mechanical strength.

(Preparation of cellulose fiber containing oxidized cellulose)
Cellulose fibers containing oxidized cellulose in the present embodiment can be produced, for example, according to the following methods (1) to (5).

(1) First, about 10 to 1000 times the amount of water is added to the cellulose raw material on a mass basis to form a slurry.
The cellulose raw material is not particularly limited as long as it contains cellulose, and examples thereof include various wood pulp, non-wood pulp, bacterial cellulose, regenerated cellulose, waste paper pulp, cotton, valonia cellulose, and squirt cellulose. Also, various cellulose powders and microcrystalline cellulose powders that are commercially available may be used.

(2) Next, the slurry is oxidized using an oxidation catalyst solution containing an N-oxyl compound.
At this time, it is preferable to use an oxidizing agent in combination with the N-oxyl compound. When an oxidizing agent is used in combination, the N-oxyl compound is oxidized by the oxidizing agent to produce oxoammonium salts in sequence, and cellulose is oxidized by the oxoammonium salt. According to such oxidation treatment, the oxidation reaction can proceed even under mild conditions, and the introduction efficiency of the carboxy group can be further improved.

As the N-oxyl compound, 2,2,6,6-tetramethyl-1-piperidine-N-oxyl (TEMPO), 2,2,6,6-tetramethylpiperidine-N-oxyl, 2,2,6 , 6-Tetramethyl-4-hydroxypiperidine-1-oxyl, 2,2,6,6-tetramethyl-4-phenoxypiperidine-1-oxyl, 2,2,6,6-tetramethyl-4-benzylpiperidine -1-oxyl, 2,2,6,6-tetramethyl-4-acryloyloxypiperidine-1-oxyl, 2,2,6,6-tetramethyl-4-methacryloyloxypiperidine-1-oxyl, 2,2 , 6,6-tetramethyl-4-benzoyloxypiperidine-1-oxyl, 2,2,6,6-tetramethyl-4-cinnamoyloxypiperidine-1- Xyl, 2,2,6,6-tetramethyl-4-acetylaminopiperidine-1-oxyl, 2,2,6,6-tetramethyl-4-acryloylaminopiperidine-1-oxyl, 2,2,6 6-tetramethyl-4-methacryloylaminopiperidine-1-oxyl, 2,2,6,6-tetramethyl-4-benzoylaminopiperidine-1-oxyl, 2,2,6,6-tetramethyl-4-cinna Moylaminopiperidine-1-oxyl, 4-propionyloxy-2,2,6,6-tetramethylpiperidine-N-oxyl, 4-methoxy-2,2,6,6-tetramethylpiperidine-N-oxyl, 4 -Ethoxy-2,2,6,6-tetramethylpiperidine-N-oxyl, 4-acetamido-2,2,6,6-tetramethylpiperidine N-oxyl, 4-oxo-2,2,6,6-tetramethylpiperidine-N-oxyl, 2,2,4,4-tetramethylazetidine-1-oxyl, 2,2-dimethyl-4,4 -Dipropylazetidine-1-oxyl, 2,2,5,5-tetramethylpyrrolidine-N-oxyl, 2,2,5,5-tetramethyl-3-oxopyrrolidine-1-oxyl, 2,2, 6,6-tetramethyl-4-acetoxypiperidine-1-oxyl, ditert-butylamine-N-oxyl, poly [(6- [1,1,3,3-tetramethylbutyl] amino) -s-triazine- 2,4-diyl] [(2,2,6,6-tetramethyl-4-piperidyl) imino] hexamethylene [(2,2,6,6-tetramethyl-4-piperidyl) imino and the like.
Among these, 2,2,6,6-tetramethylpiperidine-N-oxyl (TEMPO) is particularly preferable.

  The amount of the N-oxyl compound used is not particularly limited, but is usually in the range of 0.1 parts by mass or more and 10 parts by mass or less with respect to 100 parts by mass of the solid content of the cellulose raw material to be oxidized. It is in the range of 5 parts by mass or more and 5 parts by mass or less.

Examples of oxidizing agents include halogens such as bromine, chlorine, and iodine, hypohalous acids, halous acids and perhalogen acids, or salts, halogen oxides, nitrogen oxides, peroxides, and the like. If it can promote, it will not be specifically limited.
The amount of the oxidizing agent used is usually in the range of 1 to 100 parts by mass, preferably in the range of 5 to 50 parts by mass, based on 100 parts by mass of the solid content of the cellulose raw material to be oxidized. Is within.

In addition to the N-oxyl compound and the oxidizing agent, at least one selected from bromide and iodide may be used in combination as a catalyst other than the N-oxyl compound.
Examples of bromides include alkali metal bromide salts such as sodium bromide. Examples of the iodide include alkali metal iodides such as sodium iodide.
The amount of the catalyst selected from bromide and iodide can be selected as long as the oxidation reaction can be promoted, and is not particularly limited. It is usually in the range of more than 0 parts by mass and 100 parts by mass or less, preferably in the range of 5 parts by mass to 50 parts by mass with respect to 100 parts by mass of the solid content of the cellulose raw material to be oxidized.

  Water can be used as the solvent. In order to improve the permeability of the oxidation catalyst solution, alcohols such as methanol and ethanol and various surfactants may be contained.

  The pH of the oxidation catalyst solution can be set, for example, in the range of 9 or more and 12 or less. Further, the temperature and time of the oxidation treatment are not particularly limited because they are appropriately set depending on the amount of the cellulose raw material to be treated. For example, the oxidation treatment is performed in the range of 1 ° C. to 60 ° C. for 1 minute to 500 minutes. Can do.

  By appropriately adjusting the above oxidation treatment conditions, the carboxyl group content of the oxidized cellulose described above can be adjusted within a desired range. Moreover, by adjusting the carboxyl group content of the oxidized cellulose, the fiber diameter and fiber length of the cellulose fiber can be adjusted by electrostatic repulsion of the carboxyl group.

  (3) Subsequently, the used catalyst or the like is removed by washing with water and the like, and if necessary, a fibrous or powdery intermediate can be obtained.

(4) Thereafter, the intermediate may be dispersed in a solvent such as water and subjected to a finer treatment as necessary. The miniaturization treatment can be performed by, for example, a homogenizer, a cutter mill, a ball mill, a jet mill, a single or twin screw extruder, a mixer, and the like.
By adjusting the conditions for the refinement treatment, the cellulose fibers can be adjusted to a desired fiber diameter and fiber length.

  (5) Finally, a dispersion or a dry-processed powdery cellulose fiber can be obtained. In addition, water can be used as a solvent for the dispersion. The dispersion may contain an organic solvent such as ethanol, a surfactant, an acid, a base, or the like.

(Ethylene / unsaturated carboxylic acid copolymer or its ionomer resin)
Next, the ethylene / unsaturated carboxylic acid copolymer or its ionomer resin in the present embodiment will be described.

"Ethylene / unsaturated carboxylic acid copolymer"
In the ethylene / unsaturated carboxylic acid copolymer, the copolymerization amount of the unsaturated carboxylic acid is preferably 1% by mass or more and 35% by mass or less, more preferably from the viewpoint of transparency and availability. It is 5 mass% or more and 25 mass% or less, Most preferably, it is 9 mass% or more and 23 mass% or less.

Examples of the unsaturated carboxylic acid in the ethylene / unsaturated carboxylic acid copolymer include acrylic acid, methacrylic acid, maleic acid, fumaric acid, itaconic acid, maleic anhydride, itaconic anhydride, monomethyl maleate, and maleic acid. And monoethyl. Among these, at least one selected from the group consisting of acrylic acid and methacrylic acid is preferable from the viewpoint of polymer productivity and hygiene.
In addition, these unsaturated carboxylic acids may be used individually by 1 type, and may be used in combination of 2 or more type.

  The ethylene / unsaturated carboxylic acid copolymer may be not only a binary copolymer of ethylene and an unsaturated carboxylic acid but also a multi-component copolymer in which other monomers are arbitrarily copolymerized. .

Other copolymer components that may be optionally copolymerized include, for example, vinyl esters such as vinyl acetate and vinyl propionate; methyl acrylate, ethyl acrylate, isopropyl acrylate, isobutyl acrylate, and acrylic acid n -Unsaturated carboxylic acid esters such as butyl, isooctyl acrylate, 2-ethylhexyl acrylate, methyl methacrylate, ethyl methacrylate, isobutyl methacrylate, dimethyl maleate, diethyl maleate; carbon monoxide; sulfur dioxide It is done.
Among these, unsaturated carboxylic acid esters are preferable, and at least one selected from the group consisting of acrylic acid esters and methacrylic acid esters is particularly preferable. In addition, these other copolymerization components may be used individually by 1 type, and may be used in combination of 2 or more type.

  When the ethylene / unsaturated carboxylic acid copolymer further contains an unsaturated carboxylic acid ester such as an acrylic acid ester and a methacrylic acid ester as a copolymerization component, it is preferable in terms of improving the flexibility of the resulting molded product. . When the ethylene / unsaturated carboxylic acid-based copolymer further contains an unsaturated carboxylic acid ester, the copolymerization amount of the unsaturated carboxylic acid ester is preferably more than 0% by mass and 30% by mass or less, more preferably. Is 5 mass% or more and 30 mass% or less.

  The ethylene / unsaturated carboxylic acid copolymer has a melt flow rate at 190 ° C. under a load of 2160 g (according to JIS K7210-1999), preferably 1 g / 10 min to 1000 g / 10 min, more preferably 5 g. / 10 minutes or more and 750 g / 10 minutes or less, and particularly preferably 10 g / 10 minutes or more and 500 g / 10 minutes or less. MFR within the above range is preferable in terms of formability and workability.

The method for producing the ethylene / unsaturated carboxylic acid copolymer is not particularly limited, but can be produced by a known polymerization method. For example, it can be obtained by radical copolymerization of ethylene and an unsaturated carboxylic acid under high temperature and high pressure.
The ethylene / unsaturated carboxylic acid copolymer in the present embodiment is usually a random copolymer.

  Further, in the ethylene / unsaturated carboxylic acid copolymer in the present embodiment, a part or all of the carboxyl groups are ammonia, methylamine, dimethylamine, trimethylamine, ethylamine, diethylamine, triethylamine, ethylenediamine, diethylenetriamine, triethylenetetramine, It is preferably neutralized with an amino compound such as 1,3-dimethylaminocyclohexane.

  The degree of neutralization of the carboxyl group of the ethylene / unsaturated carboxylic acid copolymer is preferably 10 mol% or more and 100 mol% or less, more preferably 15 mol% or more and 85 mol% or less, and particularly preferably. It is 20 mol% or more and 80 mol% or less. When the degree of neutralization is within the above range, the dispersibility of the cellulose fiber in the resin composition can be further improved.

  The ethylene / unsaturated carboxylic acid copolymer neutralized with the amino compound can be obtained, for example, by mixing and reacting an ethylene / unsaturated carboxylic acid copolymer and an amino compound.

"Ionomer resin"
The ionomer resin in the present embodiment is obtained by neutralizing part or all of the carboxyl groups of the ethylene / unsaturated carboxylic acid copolymer with metal ions.
The degree of neutralization of the carboxyl group of the ethylene / unsaturated carboxylic acid copolymer is preferably 10 mol% or more and 100 mol% or less, more preferably 15 mol% or more and 85 mol% or less, and particularly preferably. It is 20 mol% or more and 80 mol% or less. When the degree of neutralization is within the above range, the dispersibility of the cellulose fiber in the resin composition can be further improved.

Examples of metal ions constituting the ionomer resin include alkali metal ions such as lithium ions, sodium ions, and potassium ions; magnesium ions, calcium ions, zinc ions, cobalt ions, nickel ions, manganese ions, lead ions, and copper ions. And polyvalent metal ions such as titanium ions, iron ions, aluminum ions, and zirconium ions.
Among these, sodium ion, zinc ion or magnesium ion is particularly preferable. These metal ions may be used alone or in combination of two or more.

  In addition, the ionomer resin in the present embodiment is an amino compound such as ammonia, methylamine, dimethylamine, trimethylamine, ethylamine, diethylamine, triethylamine, ethylenediamine, diethylenetriamine, triethylenetetramine, 1,3-dimethylaminocyclohexane in addition to metal ions. May be included.

  The ionomer resin can be obtained, for example, by reacting an ethylene / unsaturated carboxylic acid copolymer with an oxide, hydroxide, carbonate or the like containing the metal ion.

  In this embodiment, as an ionomer resin, you may use individually by 1 type and may be used in combination of 2 or more type.

(Production method of resin composition)
Although the manufacturing method of the resin composition in this embodiment is not specifically limited, For example, the dispersion (A) containing the cellulose fiber mentioned above, the ethylene-unsaturated carboxylic acid copolymer mentioned above, or its ionomer resin is water etc. It is obtained by mixing the dispersion (B) dispersed in the dispersion medium.

  The method for mixing the dispersions (A) and (B) is not particularly limited. For example, the dispersions (A) and (B) can be mixed with stirring or shaking.

The resin composition in the present embodiment is, for example, dry blended or melt blended with the above-described cellulose fiber and the above-described ethylene / unsaturated carboxylic acid copolymer or its ionomer resin simultaneously or sequentially. Can also be obtained.
Various mixers such as a Henschel mixer and a tumbler mixer can be used for the dry blending.
In the case of melt blending, melt kneading can be performed using a kneading apparatus such as a single or twin screw extruder, a Banbury mixer, a roll, a kneader.

  In the resin composition of the present embodiment, when the total of the cellulose fiber and the ethylene / unsaturated carboxylic acid copolymer or its ionomer resin is 100% by mass, the content of the cellulose fiber is preferably 0.00. It is 1 mass% or more and 99 mass% or less, More preferably, it is 0.1 mass% or more and 95 mass% or less. When the content of the cellulose fiber is within the above range, the dispersibility of the cellulose fiber in the resin composition can be further improved.

In addition, the resin composition in the present embodiment preferably has a surface resistivity of a coating film made of the resin composition of 1 × 10 ⁷ Ω at an applied voltage of 500 V measured in an environment of a temperature of 23 ° C. and a humidity of 50%. / sq to 1 × 10 ¹² Ω / sq, more preferably 1 × 10 ⁹ Ω / sq to 1 × 10 ¹¹ Ω / sq. The dispersibility in the molded object of a cellulose fiber can be improved further as the surface resistivity of the coating film which consists of the said resin composition exists in the said range.

(Molding material)
The molding material in this embodiment contains the said resin composition. In the present embodiment, the molding material is a thermoplastic resin such as polyvinyl chloride, polypropylene, polyethylene, polystyrene, polycarbonate, nylon, and polyethylene terephthalate; a coupling agent, an inorganic filler, an organic filler, and an ultraviolet absorber. , Antioxidant, light stabilizer, anti-aging agent, light diffusing agent, plasticizer, organic dye, dye, pigment, lubricant, impact modifier, metal deactivator, flame retardant, flame retardant aid, slip agent , Additives such as reinforcing agents, mold release agents, etc. may be contained alone or in combination of two or more.

(Molded body)
The molded body in the present embodiment is, for example, a sheet shape, a film shape, a plate shape, and other three-dimensional shapes by the known molding methods such as extrusion molding, injection molding, compression molding, and hollow molding. It can be obtained by molding into various shapes.
Further, the molded body in the present embodiment can also be obtained by applying the above molding material to the object to be treated, spraying, etc., and then drying and molding it into a film shape.

  Further, the molded body in the present embodiment may be subjected to a hard coat treatment with an inorganic or organic compound, an antistatic treatment, an antireflection treatment, an electromagnetic shielding treatment or the like on the surface within a range not impairing the effects of the present invention. . These treatments can be performed on the surface of the molded body by vapor deposition, sputtering, dipping, thermal transfer, or the like.

The resin composition in the present embodiment is excellent in dispersibility of cellulose fibers. For this reason, when a molding material containing the resin composition in the present embodiment is used, a molded body with less unevenness in physical properties such as mechanical strength can be obtained. Furthermore, since the cellulose fibers are uniformly dispersed in the molded body, a molded body having excellent transparency can be obtained.
Moreover, if the molding material containing the resin composition in this embodiment is used, the surface resistivity of a molded object can be reduced. Therefore, it is possible to obtain a molded article having excellent chargeability.

  The molded body in the present embodiment is not particularly limited. For example, optical materials, interior / exterior parts of electric / electronic devices, trays for electronic parts, automotive materials, various mechanical parts, housing / building materials, pipes, tubes, It can be used in a wide range of fields such as toys and household goods.

  As mentioned above, although embodiment of this invention was described, these are illustrations of this invention and various structures other than the above are also employable.

  Hereinafter, the present embodiment will be described with reference to examples and comparative examples, but the present embodiment is not limited thereto.

(Materials used)
In the examples and comparative examples, the following materials were used.

(Resin dispersion)
(1) Resin DSP1: An aqueous dispersion of a 50 mol% Na neutralized product of an ethylene / methacrylic acid copolymer (methacrylic acid content: 20% by mass, MFR 60 g / 10 min), solid content concentration 1% by mass
(2) Resin DSP2: An aqueous dispersion of 50 mol% Na neutralized product of ethylene / methacrylic acid copolymer (methacrylic acid content: 20 mass%, MFR 60 g / 10 min), solid content concentration 27 mass%
(3) Resin DSP3: aqueous dispersion of 75 mol% NH ₃ neutralized product of ethylene / acrylic acid copolymer (acrylic acid content: 20 mass%, MFR 300 g / 10 min), solid content concentration 24 mass%
(4) Resin DSP 4: ethylene-acrylic acid copolymer (acrylic acid content: 20 wt%, MFR300g / 10 min) aqueous dispersion of 75 mole% NH ₃ neutralization product of a solid content concentration of 1 mass%
(5) Resin DSP5: An aqueous dispersion of ethylene / vinyl acetate copolymer (vinyl acetate content: 19% by mass, MFR 150 g / 10 min), solid content concentration 15% by mass
(6) Resin DSP6: aqueous dispersion of ethylene / vinyl acetate copolymer (vinyl acetate content: 19% by mass, MFR 150 g / 10 min), solid content concentration 1% by mass

As the oxidized cellulose fiber dispersion, a TEMPO oxidized cellulose fiber dispersion (manufactured by Nippon Paper Industries Co., Ltd., solid content concentration 1% by mass, average fiber diameter 2.7 nm) was used.

[Example 1]
(Preparation of PET coating film)
The resin DSP1 and the oxidized cellulose fiber dispersion were stirred and mixed so that the ethylene / methacrylic acid copolymer and the oxidized cellulose fiber had a blending ratio (parts by mass) shown in Table 1. The obtained dispersion was applied to a corona-treated PET film (thickness: 100 μm) with a bar coater (No. 32). Then, it dried at 150 degreeC for 10 minute (s), and obtained the PET coating film.

(Production of press sheet)
The dispersion prepared by the same method as that for the PET coating film was dried at room temperature, and the solid content was taken out. Subsequently, the solid content was heat-pressed under the following conditions to form a sheet.
Heating press conditions: each temperature (130 ° C, 150 ° C), heating for 1 minute, pressurizing for 1 minute Cooling conditions: 20 ° C for 3 minutes.

[Examples 2 to 9 and Comparative Examples 1 to 6]
Examples 2 to 9 and Comparative Examples 1 to 6 were carried out except that the type of the resin DSP used was changed to that shown in Table 1, and the compounding ratio of the resin and cellulose fiber was changed to the values shown in Table 1. A PET coating film and a press sheet were prepared in the same manner as in Example 1. However, 100% resin DSP was coated on a PET film with a bar coater (No. 3).

(Evaluation of resin composition)
The following evaluation was performed about the obtained PET coating film and press sheet, respectively.

(1) Measurement of pencil hardness The surface of the press sheet was scratched in order from a pencil with a hard lead, and the hardness of the lead that was not damaged was recorded.

(2) Water resistance measurement of coating film The PET coating film was immersed in ion exchange water for 2 hours, and the state of the taken-out coating film was observed visually. The coating film swollen by water was designated as water resistance x, the coating film in which swelling was not observed was designated as water resistance ◯, and the middle was designated as Δ.

(3) Measurement of total light transmittance and HAZE The total light transmittance was measured using a haze / transmittance meter (HM-150, manufactured by Murakami Color Research Laboratory) in accordance with JIS K7361.
HAZE was measured using a haze / transmittance meter (HM-150, manufactured by Murakami Color Research Laboratory Co., Ltd.) according to JIS K7136, and calculated from the following equation.
HAZE (%) = (total light transmittance−parallel light transmittance) / total light transmittance Note that the light is perpendicular to the light source of the haze / transmittance meter (the state where the incident light angle to the PET coating is 0 degree). Then, the measurement was performed with the PET coating film set up.

(4) Measurement of yellow index (YI) Using a color computer (SM-7-1S-2B, manufactured by Suga Test Instruments Co., Ltd.), the yellow index (YI) was measured using a two-optical path 8 / d transmission method.

(5) Measurement of surface resistivity The surface resistivity (Ω / sq) is measured using a surface resistivity meter (Hiresta-UP, manufactured by Mitsubishi Chemical Analytech) and a measurement probe (URS, manufactured by Mitsubishi Chemical Analytech). , Measurement was performed under conditions of an applied voltage of 500 V, a measurement time of 10 seconds, and a temperature of 23 ° C. Before the measurement, the PET coating film was allowed to stand for 48 hours in an environmental tester adjusted to a humidity of 50% or a humidity of 30%, and after sufficiently absorbing moisture, the surface resistivity was measured.

(Dispersibility evaluation 1 of cellulose fiber)
After the resin dispersion and the oxidized cellulose fiber dispersion were mixed and stirred, the case where the oxidized cellulose fiber was visually dispersed was indicated as ◯, and the case where it was not dispersed was indicated as ×.

(Dispersibility evaluation 2 of cellulose fiber)
In the production of the above-mentioned press sheet, a case where a uniform sheet was obtained was marked with ◯, and a sheet which was separated and became a non-uniform sheet was marked with x.

(Evaluation results)
The above evaluation results are summarized in Table 1. As can be seen from Table 1, the resin composition of the present embodiment was excellent in dispersibility of cellulose fibers. Therefore, the obtained coating film was excellent in the balance of mechanical strength, water resistance, transparency and surface resistivity.

Claims (12)

Cellulose fiber,
An ethylene / unsaturated carboxylic acid copolymer or an ionomer resin thereof containing ethylene and an unsaturated carboxylic acid as a copolymerization component;
A resin composition comprising: The resin composition according to claim 1,
The resin composition whose cellulose which comprises the said cellulose fiber is an oxidized cellulose. The resin composition according to claim 2,
The oxidized cellulose is a resin composition obtained by oxidizing cellulose using an N-oxyl compound as an oxidation catalyst. In the resin composition according to claim 2 or 3,
The resin composition whose average fiber diameter of the said cellulose fiber is 1 nm or more and 100 nm or less. In the resin composition as described in any one of Claims 1 thru | or 4,
The surface resistivity of the coating film made of the resin composition at an applied voltage of 500 V measured in an environment of a temperature of 23 ° C. and a humidity of 50% is 1 × 10 ⁷ Ω / sq to 1 × 10 ¹² Ω / sq. , Resin composition. In the resin composition as described in any one of Claims 1 thru | or 5,
When the total of the cellulose fiber and the ethylene / unsaturated carboxylic acid copolymer or its ionomer resin is 100% by mass,
The resin composition whose content of the said cellulose fiber is 0.1 to 99 mass%. In the resin composition as described in any one of Claims 1 thru | or 6,
The resin composition in which the ethylene / unsaturated carboxylic acid copolymer is a random copolymer of the ethylene and the unsaturated carboxylic acid. In the resin composition as described in any one of Claims 1 thru | or 7,
The resin composition, wherein the unsaturated carboxylic acid is at least one selected from the group consisting of acrylic acid and methacrylic acid.   The molding material containing the resin composition as described in any one of Claims 1 thru | or 8. The molding material according to claim 9,
Further, a molding material containing a thermoplastic resin.   The molded object obtained by shape | molding the molding material of Claim 9 or 10. A dispersion (A) containing cellulose fibers;
A dispersion (B) containing an ethylene / unsaturated carboxylic acid copolymer or an ionomer resin thereof containing ethylene and an unsaturated carboxylic acid as a copolymerization component;
The manufacturing method of the resin composition including the process of mixing.