JP6944861B2 - Method for Producing Cellulose-Containing Porous Resin Mold - Google Patents

Description

The present invention can be suitably used for a method for producing a cellulose-containing porous resin molded product used for a separator or the like.

Batteries such as lithium-ion batteries are widely used for automobiles and infrastructure. The positive electrode and the negative electrode of a battery are separated by a porous insulator called a separator, and in order to improve the characteristics of this separator, the use of a resin molded body having improved strength with cellulose nanofibers is being studied.

For example, in Patent Document 1 below (Japanese Unexamined Patent Publication No. 2005-194314), a resin composition is prepared by blending a starch-based substance such as brown rice or milled rice in a resin composition composed of a thermoplastic resin and a wood-based material. A technique for forming a composite material of a thermoplastic resin composition having excellent mechanical strength and discoloration by ultraviolet rays is disclosed by utilizing the fact that the melt viscosity of the resin composition is lowered and the kneadable temperature of the resin composition is also lowered. ..

Further, in Patent Document 2 below (Japanese Unexamined Patent Publication No. 2012-188654), a part of the hydroxyl group of cellulose is replaced with a carboxy group and / or a formyl group of 0.1 mmol / g or more with respect to the weight of the cellulose fiber. Further, a cellulose fiber substituted with a chemically modifying group other than a carboxy group and a formyl group and a cellulose fiber composite material using the cellulose fiber are disclosed.

Further, Patent Document 3 (Japanese Unexamined Patent Publication No. 2013-0569558) discloses a method for producing a polyolefin microporous stretched film containing cellulose nanofibers. Specifically, a step of melt-kneading cellulose nanofibers and a polyolefin resin, removing water from the kneaded product, mixing a plasticizer, and melt-kneading the mixture to obtain a polyolefin resin composition is disclosed. Then, a step of extruding and stretching this polyolefin resin composition and then extracting a plasticizer is disclosed.

Further, the following Patent Document 4 (Japanese Unexamined Patent Publication No. 2014-234472) discloses a method for producing a cellulose nanofiber microporous composite film. Specifically, a step of adding succinic anhydride to cellulose fine powder to prepare a cellulose monoesterified product, dissolving the obtained monoesterified cellulose in water, and performing an ultra-high pressure counter-collision treatment to form a water slurry. Is disclosed. Then, a step of forming a cellulose nanofiber composite polyolefin preblend material by mixing polyolefin (HDPE) with a water slurry, melt-kneading it with a twin-screw extruder with a steam vent, and extruding it with a strand die is disclosed. There is. Further, a step of forming a sheet of a mixture of a preblend material and paraffin and degreasing with methylene chloride is disclosed.

Further, in Patent Document 5 below (Japanese Patent Application No. 2009-293167), a polybasic acid anhydride (particularly, a dibasic acid anhydride) is semi-esterified at a temperature of 140 ° C. or lower in a part of the hydroxyl group of cellulose. A technique for producing nanofibers by introducing a carboxyl group to prepare a polybasic acid semi-esterified cellulose and converting the polybasic acid semi-esterified cellulose into fine fibers is disclosed. Further, a technique for preparing a composite material by kneading nanofibers and a resin is disclosed.

Japanese Unexamined Patent Publication No. 2005-194314 Japanese Unexamined Patent Publication No. 2012-188654 Japanese Unexamined Patent Publication No. 2013-0569558 Japanese Unexamined Patent Publication No. 2014-234472 Japanese Patent Application No. 2009-293167

The present inventor is engaged in research and development on a method for manufacturing a resin molded product using cellulose nanofibers and a manufacturing apparatus for manufacturing the same, and more efficiently used cellulose nanofibers having good characteristics. We are diligently studying the technology for manufacturing resin molded products. As a result, we have found a manufacturing technique that can simplify the manufacturing process and improve the characteristics of the resin molded product using cellulose nanofibers.

Other challenges and novel features will become apparent from the description and accompanying drawings herein.

The method for producing a cellulose-containing porous resin molded product disclosed in the present application includes (a) a step of forming a first mixture by mixing powdered cellulose, an additive and a plasticizer, and (b) the first. It has a step of forming a kneaded product by kneading a mixture and a polyolefin, (c) a step of forming a film by stretching the kneaded product, and (d) a step of bringing the film into contact with an organic solvent.

The method for producing a cellulose-containing porous resin molded product disclosed in the present application is as follows: (a) A dispersion liquid and a polyolefin are charged into the kneading extruder of a manufacturing apparatus having a kneading extruder and a drawing machine, and kneaded by kneading. It has a step of forming a product, and (b) a step of forming a film by stretching the kneaded product with the stretching machine. The dispersion is a mixture of powdered cellulose, an additive, and a plasticizer.

The method for producing a cellulose-containing porous resin molded product disclosed in the present application is as follows: (a) Powdered cellulose in the first processing section of the kneading extruder of a manufacturing apparatus having a kneading extruder, a stretching machine and an extraction tank. It comprises a step of mixing an additive and a plasticizer to prepare a dispersion, and kneading the polyolefin and the dispersion in a second treatment section connected to the first treatment section to form a kneaded product. Then, it has (b) a step of forming a film by stretching the kneaded product with the stretching machine, and (c) a step of bringing the film into contact with an organic solvent by the extraction tank.

According to the method for producing a cellulose-containing porous resin molded product disclosed in the present application, the production process can be simplified and a cellulose-containing porous resin molded product having good characteristics can be produced.

It is a figure (photograph) which shows the appearance of a kneader (a tabletop twin-screw kneader). It is a figure (photograph) which shows the appearance of a press machine. It is a figure (photograph) which shows the appearance of the tabletop stretching machine. It is an SEM photograph of the separator of Example 1. It is an SEM photograph of the separator of Example 2. It is an SEM photograph of the separator of Example 3. It is an SEM photograph of the separator of Comparative Example A. It is an SEM photograph of the separator of Comparative Example B. It is an SEM photograph of the separator of Comparative Example C. It is a schematic diagram which shows the structure of the manufacturing apparatus (system) of Embodiment 2. It is sectional drawing which shows the structure of the twin-screw kneading extruder. It is sectional drawing which shows the structure of the twin-screw kneading extruder. 13 (a) and 13 (b) are perspective views showing a shape example of the screw (screw piece). It is sectional drawing which shows the structure of the kneader for batch processing. It is a perspective view of the 1st transverse stretching apparatus. 16 (a) to 16 (c) are cross-sectional views showing a schematic configuration of a clip and its operation.

Hereinafter, embodiments will be described in detail based on examples and drawings. In all the drawings for explaining the embodiment, the members having the same function are designated by the same reference numerals, and the repeated description thereof will be omitted.

(Embodiment 1)
The manufacturing process of the cellulose nanofiber-containing porous resin molded product of the present embodiment will be described below. The cellulose nanofiber-containing porous resin molded product of the present embodiment is a so-called battery separator. As will be described later, the step of forming a separator that forms a large number of fine holes in the resin molded product by the step of removing the plasticizer is called a "wet method".

The manufacturing process of the cellulose nanofiber-containing porous resin molded product of the present embodiment has the following steps.

(A: Dispersion liquid adjustment step)
In this step, a dispersion (mixture) is prepared by mixing cellulose nanofibers, an additive (for example, succinic anhydride) and a plasticizer (for example, liquid paraffin).

Cellulose nanofibers are fine powdered cellulose.

Cellulose is a carbohydrate represented by (C ₆ H ₁₀ O ₅ ) _n. For example, it is represented by the following chemical structural formula (Chemical formula 1).

なお、以下の化学構造式（化２）に示すように、（Ｃ₆Ｈ₁₀Ｏ₅）_nで表される炭水化物の複数の水酸基の一部が水酸基を有する基（例えば、−ＣＨ₂ＯＨのような−Ｒ−ＯＨ）と置換されたセルロースを用いてもよい。

As shown in the following chemical structural formula (Chemical formula 2), a group in which some of the plurality of hydroxyl groups of the carbohydrate represented by _{(C 6} H ₁₀ O ₅ ) _{n has hydroxyl groups (for example, −CH 2} OH). Cellulose substituted with —R—OH) may be used.

セルロースナノファイバー（以下、ＣｅＮＦを示す場合がある）は、パルプなどを原料とし、パルプなどに含まれるセルロース繊維をナノメートルサイズまで微細化したものである。例えば、パルプを加水分解し、生成したものをセルロースナノファイバーとして用いることができる。セルロースの分子鎖が緻密かつ規則的に存在する部分を結晶セルロースと言うことがある。

Cellulose nanofibers (hereinafter, may be referred to as CeNF) are made from pulp or the like as a raw material, and the cellulose fibers contained in the pulp or the like are refined to a nanometer size. For example, the product obtained by hydrolyzing pulp can be used as cellulose nanofibers. The portion where the molecular chains of cellulose are densely and regularly present is sometimes called crystalline cellulose.

The shape of the powdered cellulose fiber constituting the cellulose nanofiber is not limited, and for example, an elongated particle shape or a substantially spherical shape can be used.

When using elongated particle-shaped cellulose fibers, the fiber diameter (diameter R) is 0.001 μm or more and 50 μm or less, the fiber length (L) is 0.5 μm or more and 10 μm or less, and the aspect ratio (L / R) is 100. It is preferable to use one having a value of 1,000,000 or more and 1,000,000 or less. As described above, the efficiency of defibration can be improved by using the cellulose nanofibers having an elongated particle shape.

Cellulose nanofibers are lightweight, have high strength, and have heat resistance. Therefore, it is useful as a reinforcing fiber for fiber-reinforced plastics (FRP). That is, the strength of the molded product can be improved by mixing cellulose nanofibers in the resin. In particular, cellulose nanofibers having a fiber diameter reduced to a nanometer size can be contained in a resin molded body at a high density, and the strength of the resin molded body can be efficiently improved. In addition, since cellulose nanofibers are derived from plant fibers such as pulp, they are beneficial because they have a small environmental load during production and product disposal.

Additives are used to make cellulose nanofibers hydrophobic (oil-based). As can be seen from the above-mentioned chemical structural formulas (Chemical formulas 1 and 2), cellulose nanofibers are hydrophilic because they have a hydroxyl group (hydrophilic group), and are composited by mixing with a base material of a resin (for example, polyolefin). In this case, the cellulose nanofibers tend to aggregate due to hydrogen bonds to form a lump, and it is difficult to uniformly disperse them in the base material.

Therefore, by treating the hydroxyl groups of the cellulose nanofibers with an additive (for example, a carboxylic acid compound) for hydrophobic treatment (lipophilic treatment), the dispersibility in the base material can be improved. That is, the hydroxyl group (−OH) portion of cellulose can be replaced with a hydrophobic group. Specifically, a part of the hydroxyl groups of the cellulose nanofibers is esterified with a carboxylic acid compound (R-CO-OH). In other words, the hydroxyl group (-OH) portion of cellulose is an ester bond (-O-CO-R). Esterification makes it hydrophobic (lipophilic). That is, the esterified cellulose nanofibers become hydrophobic (lipophilic).

The hydroxyl group (-OH) portion of cellulose may be hydrophobized (oil-based) by forming an ether bond (-OR). As the additive for etherification, for example, an organic solvent having a three-membered ring cyclic ether structure such as ethylene oxide or propylene oxide can be used. Further, by introducing a large molecule as the above R, a steric damage effect can be imparted. Therefore, the dispersibility of the cellulose nanofibers is enhanced, and aggregation can be suppressed.

Plasticizers are intended to improve the flexibility and resistance to weathering in addition to the thermoplastic resin. Further, in the present embodiment, holes can be provided in the resin molded body (membrane) by removing the plasticizer by the degreasing step described later.

As the plasticizer, an organic solvent having a molecular weight of 100 to 1500 and a boiling point of 50 ° C. to 300 ° C. can be used. Specifically, liquid paraffin, nonane, decane, decalin, paraxylene, undecane, chain or cyclic aliphatic hydrocarbons of dodecane, mineral oil distillates having corresponding boiling points, and dibutylphthalate and dioctylphthalate. At room temperature, one or a mixture of liquid phthalates can be used. Among alcohols such as ethanol and methanol, nitrogen-based organic solvents such as NMP (N-methyl-2-pyrrolidone) and dimethylacetamide, ketones such as acetone and methyl ethyl ketone, and esters such as ethyl acetate and butyl acetate. One or several mixtures can be used.

Regarding the dispersion liquid (mixture) of the cellulose nanofibers, the additive and the plasticizer, the mixing ratio of each can be as follows. For example, based on the amount of dispersion (mixture amount, total amount), cellulose nanofibers are 0.01 wt% or more and 30 wt% or less, additives are 0.01 wt% or more and 50 wt% or less, and plasticizers are 0.01 wt% or more and 99 wt% or less. Can be mixed in the range of.

As described above, by mixing the cellulose nanofibers, the additive, and the plasticizer in the dispersion liquid adjusting step, the cellulose nanofibers can be defibrated while chemically modifying the cellulose nanofibers. That is, the cellulose nanofibers are defibrated by swelling the plasticizer in the cellulose nanofibers.

Here, a surfactant may be added to the dispersion liquid. By adding a surfactant, the plasticizer can penetrate into the cellulose nanofibers, particularly into the crystalline cellulose. Therefore, the defibration property of the cellulose nanofibers is enhanced. Further, the addition of the surfactant enhances the dispersibility of the cellulose nanofibers in the resin described later.

As the surfactant, it is preferable to use a surfactant having a surface tension measured by the Wilhelmy method of 10 or more and 70 or less and a contact angle of 30 ° or more and 95 ° or less. As the surfactant, any of anionic surfactant, cationic surfactant, amphoteric surfactant, nonionic surfactant and the like may be used, and two or more of these may be used in combination.

As the anionic surfactant, a sulfate ester type anionic surfactant such as an alkyl sulfate ester salt, an alkenyl sulfate ester salt, a polyoxyalkylene alkyl ether sulfate ester salt, or a polyoxyalkylene alkenyl ether sulfate ester salt can be used.

Examples of the cationic surfactant include quaternary ammonium salts, pyridinium salts, tertiary amines or secondary amines having a hydrocarbon group having 12 to 28 carbon atoms, which may be separated by an amide group, an ester group or an ether group. Mineral acid, organic acid salt and the like can be used.

As the amphoteric tenside, alkylcarbobetaine, alkylsulfobetaine, alkylhydroxysulfobetaine, alkylamidehydroxysulfobetaine, alkylamideamine-type betaine, alkylimidazoline-type betaine, alkylamidepropylbetaine, alkylhydroxysulfobetaine, lecithin and the like are used. be able to.

Nonionic surfactants include polyoxyethylene hydrogenated castor oil, polyoxyethylene castor oil, polyoxyethylene solebitan fatty acid ester, polyoxyethylene sorbitol fatty acid ester, polyoxyethylene glycerin fatty acid ester, and oxyethylene chain type surfactant. Can be used.

The amount of the surfactant added can be, for example, 0.02 wt% or more and 6 wt% or less with respect to the amount of the dispersion liquid (mixture amount, total amount). The reaction (esterification, etherification) time can be adjusted, for example, in the range of 0.5 minutes or more and less than 60 minutes. Since this reaction time greatly affects the production rate, it is more preferably 0.5 minutes or more and 30 minutes or less, and further preferably 0.5 minutes or more and 15 minutes or less. The reaction rate can be increased by increasing the mixing property (kneading property) of the dispersion liquid. For example, by using the twin-screw kneading extruder described in detail in the second embodiment, the mixing property (kneading property) of the dispersion liquid can be improved. In addition to the twin-screw kneading extruder, a single-screw kneading extruder or a multi-screw kneading extruder having two or more shafts may be used. Further, when a single-screw or multi-screw kneading extruder is used, it is possible to physically defibrate cellulose nanofibers by changing the shape of the screw as described later. Examples of the shape of the screw having the defibration ability include a shape called a kneading disc (see FIG. 13B), which will be described later.

(B: Kneading process)
In this step, a kneaded product is formed by kneading the dispersion liquid (mixture) prepared in the dispersion liquid adjusting step and the polyolefin (resin).

As the polyolefin, those that can be processed by ordinary extrusion, injection, inflation, blow molding, or the like are used. For example, as the polyolefin, homopolymers and copolymers such as ethylene, propylene, 1-butene, 4-methyl-1-pentene, 1-hexene, and 1-octene, copolymers, and multistage polymers can be used. In addition, polyolefins selected from the group of these homopolymers, copolymers, and multistage polymers can be used alone or in combination. Typical examples of the polymer are low density polyethylene, linear low density polyethylene, medium density polyethylene, high density polyethylene, ultra high molecular weight polyethylene, isotactic polypropylene, atactic polypropylene, ethylene-propylene random copolymer, polybutene. , Polyethylene propylene rubber and the like.

When the cellulose nanofiber-containing porous resin molded product formed in the present embodiment is used as a separator for a battery, polyethylene is used as a main component because of its high melting point and high strength required performance. It is preferable to use a resin. Further, from the viewpoint of shutdown property and the like, it is preferable that polyethylene accounts for 50% by weight or more of the resin component. When an ultra-high molecular weight polyolefin having a molecular weight of 1 million or more is used, it becomes difficult to uniformly knead the ultra-high molecular weight polyolefin in excess of 50 parts by weight with respect to 100 parts by weight of the kneaded product (resin and dispersion). Therefore, it is preferably 50 parts by weight or less.

In this step, it is preferable to use the twin-screw kneading extruder described in detail in the second embodiment. In addition to the twin-screw kneading extruder, a single-screw kneading extruder or a multi-screw kneading extruder having two or more shafts may be used. By continuously processing the dispersion liquid adjusting step and this step using a twin-screw kneading extruder, the efficiency of the manufacturing process of the resin molded product can be improved.

(C: Stretching step)
In this step, a film (thin film) is formed by stretching the kneaded product formed in the kneading step (also referred to as a thinning step or a film forming step).

For example, the kneaded product is pressed to form a sheet, and the outer circumference of the sheet is stretched to form a thin film.

In this step, it is preferable to stretch the kneaded product using a stretching machine. As the stretching machine, for example, a tenter can be used.

Here, in the thin film, the polyolefin and the plasticizer are in a phase-separated state. Specifically, the plasticizer has a nano-sized island shape. By removing this nano-sized plasticizer in the organic solvent treatment step described later, the island-shaped plasticizer portion becomes pores and a porous thin film is formed.

(D: Organic solvent treatment step)
In this step, unnecessary substances in the film are removed by contacting the film (thin film) formed in the stretching step with an organic solvent.

For example, by immersing the film (thin film) formed in the stretching step in an organic solvent, the plasticizer in the film is extracted into the organic solvent and removed from the film (thin film). As described above, the removal of the plasticizer forms a porous thin film. Further, in this step, in addition to the above plasticizer, additives (unreacted additives) not used for chemical modification (esterification, etherification) are extracted into an organic solvent and removed from the film (thin film). do.

As the organic solvent, methylene chloride, hexane, octane, cyclohexane and the like can be used. Above all, it is preferable to use methylene chloride from the viewpoint of productivity.

After that, the organic solvent on the surface of the film (thin film) is volatilized and heat-treated (heat-fixed) as necessary to obtain a cellulose nanofiber-containing porous resin molded body.

According to the cellulose nanofiber-containing porous resin molded product of the present embodiment described above, it is possible to obtain a resin molded product having good characteristics while simplifying the manufacturing process.

For example, as described later, after esterifying cellulose nanofibers, unreacted additives are extracted and removed, and then dried to form powdery esterified cellulose nanofibers, and the powdery esterified cellulose nanofibers are formed. It is also possible to adopt a step of dispersing the mixture in liquid paraffin and kneading it with polyethylene (see Comparative Example B and Comparative Example C).

On the other hand, in the present embodiment, the steps of removing the unreacted additive and drying can be omitted, and the resin molded product can be produced in a shorter step. Further, the removal of the unreacted additive can be combined with the removal step of the plasticizer, so that the manufacturing process can be simplified while maintaining the characteristics of the resin molded product. Further, by omitting the removal of unreacted additives and the drying step in the previous stage of the manufacturing step, it becomes possible to continuously process the preparation and kneading steps of the dispersion liquid in the same apparatus (see FIG. 11). , The resin molded product can be manufactured more efficiently.

[Applicable products of cellulose nanofiber-containing porous resin molded products]
As described above, this cellulose nanofiber-containing porous resin molded product can be used as a separator for a battery. The cellulose nanofiber-containing porous resin molded product of the present embodiment is lightweight, has high strength, and has heat resistance, so that it can be used as a separator in a lithium ion battery.

The lithium ion battery has a positive electrode, a negative electrode, a separator and an electrolytic solution. A separator is arranged between the positive electrode and the negative electrode. The separator has a large number of micropores. For example, during charging, that is, when a charger is connected between the positive electrode and the negative electrode, the lithium ions inserted in the positive electrode active material are desorbed and released into the electrolytic solution. Lithium ions released into the electrolytic solution move in the electrolytic solution, pass through the micropores of the separator, and reach the negative electrode. The lithium ions that reach the negative electrode are inserted into the negative electrode active material that constitutes the negative electrode.

At the time of discharge, that is, when an external load is connected between the positive electrode and the negative electrode, the lithium ions inserted in the negative electrode active material are desorbed and released into the electrolytic solution. At this time, electrons are emitted from the negative electrode. Then, the lithium ions released into the electrolytic solution move in the electrolytic solution, pass through the micropores of the separator, and reach the positive electrode. The lithium ions that reach the positive electrode are inserted into the positive electrode active material that constitutes the positive electrode. At this time, by inserting lithium ions into the positive electrode active material, electrons flow into the positive electrode. In this way, discharge is performed by the movement of electrons from the negative electrode to the positive electrode.

The separator needs to be an insulator so that the positive electrode and the negative electrode are not short-circuited. Further, as described above, it is necessary to have a porous membrane that allows the passage of lithium ions. In addition, it is necessary to have resistance to the electrolytic solution.

The strength must be high enough to withstand stress during electrode formation, pressure due to expansion and contraction of the electrode during charging and discharging, and impact when the battery is dropped. In addition, lithium may precipitate from the negative electrode side due to deterioration over time (needle-like crystallization). When this precipitated lithium penetrates the separator and comes into contact with the positive electrode, a short circuit may occur. Therefore, the separator is required to have piercing strength.

The cellulose nanofiber-containing porous resin molded body of the present embodiment has high strength and high piercing strength, and can be made resistant to an electrolytic solution by selecting a resin material, and can be used as a separator. Suitable.
[Example]
Hereinafter, specific examples of the method for producing the cellulose nanofiber-containing porous resin molded product (separator) of the present embodiment will be described.

First, a separator was formed under various conditions based on the production method of the present embodiment. Moreover, the separator was formed by using the manufacturing method of the comparative example. For the formed separator, each sample was cut out to 50 mm × 50 mm and evaluated by the following test.

1) Puncture strength: For the piercing strength, the maximum load at the time of needle penetration was measured using an automated piercing strength meter (KES-FB3-AUTO manufactured by Kato Tech Co., Ltd.). Measurements were performed at 10 points on each part of the sheet, and the average value was calculated.

2) Gale value: The Gale value was measured using a Gale type automatic measuring machine (manufactured by TESTING MACHINES INC). In this measurement, as specified in JIS P8177, the time required for 100 cc of air to pass through the sheet was taken as the Gale value.

3) Surface observation (FE-SEM observation): Using a vacuum vapor deposition apparatus (E-1045 manufactured by Hitachi High-Tech), after vapor deposition of platinum with a thickness of 0.3 nm on the sheet, FE-SEM (FE-SEM) The surface was observed using SUPRA55VP manufactured by Karl Zeiss.

4) Film thickness and porosity: The film thickness was measured at 10 points on each part of the sheet using a microcage, and the average value was taken as the film thickness. The porosity was calculated by the ratio of the measured weight of the sheet to the density and the theoretical weight calculated from the volume.

5) Degree of chemical modification: For Examples 1 to 3 and Comparative Example C, first, 50 g of the dispersion liquid (mixture) was diluted with 500 g of methylene chloride and filtered to obtain CeNF. Next, this CeNF was vacuum dried at 80 ° C. for 12 hours to obtain a dried CeNF. Using this dried CeNF, the degree of chemical modification was determined as follows. For Comparative Examples A and B, dried CeNF was used as it was.

10 g of dried CeNF was weighed in a 200 ml beaker, and 100 ml each of acetone and distilled water were added to prepare a test solution. This test solution was stirred with a magnetic stirrer for 600 rpm × 10 minutes, a few drops of a phenolphthalein solution was added to the test solution, and the test solution was stirred with a magnetic stirrer for 600 rpm × 10 minutes. This test solution was titrated with a 0.1 N KOH-ethanol solution, and KOH-ethanol was added until the test solution was colored. The acid value obtained from this addition amount was taken as the degree of chemical modification of CeNF.

Further, as the processing apparatus, the apparatus shown in FIGS. 1 to 3 was used. FIG. 1 is a view (photograph) showing the appearance of a kneader (tabletop biaxial kneader), FIG. 2 is a view (photograph) showing the appearance of a press machine, and FIG. 3 is a view showing the appearance of a tabletop stretching machine. It is a figure (photograph) which shows.

(Example 1)
Ceoras FD101 (manufactured by Asahi Kasei Chemicals Co., Ltd.) was used as the cellulose nanofiber (CeNF), succinic anhydride was used as an additive, and liquid paraffin P-350P (manufactured by Moresco Co., Ltd.) was used as a plasticizer. First, CeNF and succinic anhydride (SA) were put into a kneader (tabletop biaxial kneader) as shown in FIG. 1 at a weight ratio of CeNF: succinic anhydride (SA) = 86.5: 13.5. After that, liquid paraffin P-350P was further added and kneaded at 140 ° C. for 7 minutes to obtain a dispersion liquid. Liquid paraffin P-350P was added at a ratio of 1 wt% of cellulose nanofibers in the dispersion. The esterification reaction proceeds in this dispersion.

Next, the mixture was melt-kneaded with a kneader (tabletop twin-screw kneader) shown in FIG. 1 at a ratio of 30 parts by weight of Mitsui Hi-Zex (030S) and 70 parts by weight of the dispersion liquid. The kneading temperature was 180 ° C. and the kneading time was 12 minutes. The kneader (desktop twin-screw kneader) is a device for kneading the charged raw materials with a shaft having two screws that mesh with each other (see the second embodiment and FIG. 11), and the number of rotations of the shaft (screw). Was 80 rpm.

Next, the kneaded product was processed by a press machine as shown in FIG. 2 to form a press sheet having a thickness of 1 mm. Next, the end of the press sheet was gripped by a pin (clip) by a tabletop stretching machine as shown in FIG. 3, and simultaneously biaxially stretched to form a film. Simultaneous biaxial stretching means stretching in the first direction (longitudinal direction, MD direction) and in the second direction (horizontal direction, TD direction) intersecting the first direction at the same time. The stretching conditions in the first direction (longitudinal direction, MD direction) are a stretching temperature of 110 ° C., the stretching ratio is 6 times, the stretching speed is 3000 mm / min, and the stretching conditions in the second direction (horizontal direction, TD direction) are a stretching temperature of 110. The temperature was set to 7 times, a stretching ratio of 7 times, and a stretching speed of 3000 mm / min.

The liquid paraffin was then degreased by immersing the film in methylene chloride. At this time, unreacted additives that did not contribute to the esterification reaction are also removed. Then, heat fixation was performed at 125 ° C. for 10 minutes to obtain a separator.

(Example 2)
A dispersion was obtained in the same manner as in Example 1 except for the amount of liquid paraffin P-350P added. In this example, the liquid paraffin P-350P was added at a ratio of 2 wt% of cellulose nanofibers in the dispersion liquid.

Next, in the same manner as in Example 1, 30 parts by weight of Mitsui Hi-Zex (030S) and 70 parts by weight of the dispersion liquid were kneaded, the kneaded product was formed into a film, and then the liquid paraffin was degreased and heat-fixed. , Obtained a separator.

(Example 3)
As the dispersion liquid of Example 1, a dispersion liquid to which propylene oxide (PO) was further added in addition to cellulose nanofibers (CeNF), succinic anhydride (SA) and liquid paraffin was prepared. That is, CeNF and succinic anhydride (SA) were put into a kneader (tabletop biaxial kneader) as shown in FIG. 1 at a weight ratio of CeNF: succinic anhydride (SA) = 86.5: 13.5. After that, propylene oxide (PO) and liquid paraffin P-350P were further added and kneaded at 140 ° C. for 2 hours to obtain a dispersion liquid. Propylene oxide (PO) was added so as to have a weight ratio of CeNF: propylene oxide (PO) = 89: 11. Liquid paraffin P-350P was added at a ratio of 1 wt% of cellulose nanofibers in the dispersion liquid, as in Example 1.

Next, in the same manner as in Example 1, 30 parts by weight of Mitsui Hi-Zex (030S) and 70 parts by weight of the dispersion liquid were kneaded, the kneaded product was formed into a film, and then the liquid paraffin was degreased and heat-fixed. , Obtained a separator.

(Example 4)
As the dispersion liquid of Example 1, a dispersion liquid to which a surfactant was further added in addition to cellulose nanofiber (CeNF), succinic anhydride (SA) and liquid paraffin was prepared. That is, CeNF and succinic anhydride (SA) were charged into a kneader (tabletop biaxial kneader) as shown in FIG. 1 at a weight ratio of CeNF: succinic anhydride (SA) = 86.5: 13.5. After that, lecithin as a surfactant and liquid paraffin P-350P were further added and kneaded at 140 ° C. for 2 hours to obtain a dispersion liquid. The amount of lecithin added is 2% with respect to the weight of the dispersion liquid. Liquid paraffin P-350P was added at a ratio of 1 wt% of cellulose nanofibers in the dispersion liquid, as in Example 1.

Next, in the same manner as in Example 1, 30 parts by weight of Mitsui Hi-Zex (030S) and 70 parts by weight of the dispersion liquid were kneaded, the kneaded product was formed into a film, and then the liquid paraffin was degreased and heat-fixed. , Obtained a separator.

(Comparative Example A)
As the dispersion liquid of Example 1, a dispersion liquid to which succinic anhydride (SA) was not added was prepared. That is, cellulose nanofibers (CeNF) and liquid paraffin P-350P were put into a kneader (tabletop biaxial kneader) as shown in FIG. 1 and then kneaded at 140 ° C. for 7 minutes to obtain a dispersion liquid. Liquid paraffin P-350P was added at a ratio of 1 wt% of cellulose nanofibers in the dispersion.

Next, in the same manner as in Example 1, 30 parts by weight of Mitsui Hi-Zex (030S) and 70 parts by weight of the dispersion liquid were kneaded, the kneaded product was formed into a film, and then the liquid paraffin was degreased and heat-fixed. , Obtained a separator.

(Comparative Example B)
In this comparative example, after forming powdery esterified cellulose nanofibers, a separator was formed using the powdery esterified cellulose nanofibers.

First, the cellulose nanofibers are esterified with an additive, the unreacted additive that did not contribute to the esterification reaction is removed, and the mixture is dried to obtain powdered esterified cellulose nanofibers (also referred to as SA-ized CeNF). Formed.

Specifically, cellulose nanofibers (CeNF) and succinic anhydride (SA) are added to each other in a weight ratio of CeNF: succinic anhydride (SA) = 86.5: 13.5, as shown in FIG. It was put into a twin-screw kneader) and mixed (kneaded) at 120 ° C. for 20 minutes. The unreacted additive (SA) is removed by extracting this mixed solution with acetone, and the mixture is dried in a vacuum drying oven at 80 ° C. for about 2 hours to obtain powdered esterified cellulose nanofibers (CeNF SA). ) Was formed.

A separator was formed using this powdery esterified cellulose nanofiber (CeNF SA). Specifically, powdered SA-ized CeNF and liquid paraffin P-350P were put into a kneader (tabletop twin-screw kneader) as shown in FIG. 1 and then kneaded at 140 ° C. for 7 minutes to obtain a dispersion liquid. .. Liquid paraffin P-350P was added at a ratio of 1 wt% of SA-formed cellulose nanofibers in the dispersion.

Next, in the same manner as in Example 1, 30 parts by weight of Mitsui Hi-Zex (030S) and 70 parts by weight of the dispersion liquid were kneaded, the kneaded product was formed into a film, and then the liquid paraffin was degreased and heat-fixed. , Obtained a separator.

(Comparative Example C)
In this comparative example, the etherification of cellulose nanofibers was examined. Some of the hydroxyl groups of the cellulose nanofibers are etherified with propylene oxide (R-CO-OH). In other words, the hydroxyl group (-OH) portion of cellulose is an ether bond (-OR, R = CH ₂ CH (OH) CH ₃ ). By such etherification, hydrophobicity (parenting) can be achieved. Further, as described above, by introducing a large molecule as R, a steric damage effect can be introduced, the dispersibility of the cellulose nanofibers is enhanced, and aggregation is suppressed.

Here, cellulose nanofibers (CeNF) were esterified with succinic anhydride (SA) and further etherified with propylene oxide (PO) (addition reaction).

Specifically, the powdery esterified cellulose nanofibers (Saized CeNF) and propylene oxide (PO) formed in the same manner as in Comparative Example B are weighted with SAd CeNF: propylene oxide (PO) = 89: 11. In the ratio, it was put into a pressure-resistant container and mixed (kneaded) at 140 ° C. for 2 hours. The unreacted additive (PO) is removed by extracting this mixed solution with xylene, and the mixture is dried in a vacuum drying oven at 80 ° C. for about 2 hours to form powdered ester etherified cellulose nanofibers (SAPO). (Also referred to as CeNF) was formed.

A separator was formed using this powdery ester etherified cellulose nanofiber (SAPOized CeNF). Specifically, powdered SAPOized CeNF and liquid paraffin P-350P were put into a kneader (tabletop twin-screw kneader) as shown in FIG. 1 and then kneaded at 140 ° C. for 7 minutes to obtain a dispersion liquid. .. Liquid paraffin P-350P was added at a ratio of 1 wt% of SA-formed cellulose nanofibers in the dispersion.

Next, in the same manner as in Example 1, 30 parts by weight of Mitsui Hi-Zex (030S) and 70 parts by weight of the dispersion liquid were kneaded, the kneaded product was formed into a film, and then the liquid paraffin was degreased and heat-fixed. , Obtained a separator.

(Comparative Example D)
Cellulose nanofibers (CeNF) and succinic anhydride (SA) at a weight ratio of CeNF: succinic anhydride (SA) = 86.5: 13.5, as shown in FIG. 1 kneader (desktop biaxial kneader) Liquid paraffin P-350P was further added so as to have a weight ratio of CeNF: liquid paraffin P-350P = 99: 1 and kneaded at 140 ° C. for 7 minutes to obtain a mixture. In this example, since the amount of liquid paraffin P-350P added was small, it did not become liquid. That is, the dispersion liquid was not formed, and the formation of the separator was abandoned.

(result)
Table 1 shows the raw material composition of the above Examples and Comparative Examples, the mixing ratio of polyethylene (PE) and the dispersion, the amount of CeNF added (including those esterified and etherified), the presence or absence of esterification or etherification, and unreacted. The presence or absence of the object removal process is summarized. The "step of removing unreacted material" here means a step before kneading of polyethylene (PE), and does not include removal by a degreasing step.

表２に、上記実施例および比較例において形成されたセパレータの特性を示す。また、図４〜図９にセパレータのＳＥＭ写真を示す。図４は、実施例１のセパレータに、図５は、実施例２のセパレータに、図６は、実施例３のセパレータに、図７は、比較例Ａのセパレータに、図８は、比較例Ｂのセパレータに、図９は、比較例Ｃのセパレータに、対応する。

Table 2 shows the characteristics of the separators formed in the above Examples and Comparative Examples. Further, FIGS. 4 to 9 show SEM photographs of the separator. 4 is a separator of Example 1, FIG. 5 is a separator of Example 2, FIG. 6 is a separator of Example 3, FIG. 7 is a separator of Comparative Example A, and FIG. 8 is a comparative example. Corresponding to the separator of B, FIG. 9 corresponds to the separator of Comparative Example C.

実施例１と比較例Ａの対比から、分散液に無水コハク酸を添加することにより、セルロースナノファイバーが分散液中においてエステル化（疎水化）され、混練物内（樹脂内）での分散性が向上（凝集性が抑制）され、セパレータの特性が向上していることが分かる。特に、突刺強度が向上している。

From the comparison between Example 1 and Comparative Example A, by adding succinic anhydride to the dispersion, cellulose nanofibers are esterified (hydrophobicized) in the dispersion, and dispersibility in the kneaded product (in the resin). Is improved (aggregation is suppressed), and it can be seen that the characteristics of the separator are improved. In particular, the piercing strength is improved.

Further, from the comparison between Example 1 and Comparative Example B, the separator of Example 1 has a large characteristic in terms of the characteristics of the separator as compared with the case of using powdered esterified cellulose nanofibers which have been subjected to the removal of unreacted substances and the drying treatment. No difference was observed. From the comparison between Example 3 and Comparative Example C, no significant difference was observed in the characteristics of the separator as compared with the case where the powdered ester etherified cellulose nanofibers were used. It was confirmed that even if the mixture was kneaded and stretched in a state containing the unreacted material in this way, the characteristics of the separator were not adversely affected. Comparing Example 1 and Comparative Example B, and Example 3 and Comparative Example C with respect to the degree of chemical modification (acid value), the degree of chemical modification (acid) was obtained even when chemically modified in a dispersion containing liquid paraffin. There was no significant difference in value). Therefore, it was confirmed that sufficient chemical modification treatment is possible even in the dispersion liquid containing liquid paraffin.

Further, even when the amount of liquid paraffin P-350P added is small as in Comparative Example D and a dispersion cannot be obtained, the degree of chemical modification (acid value) is about the same as in Example 1 and the like. Was confirmed. Further, from Comparative Example D, it was confirmed that it is preferable to add the liquid paraffin so that the dispersion liquid can be obtained because the dispersion liquid cannot be obtained if the amount of cellulose nanofibers is too large. For example, the amount of liquid paraffin added to the dispersion is preferably 10 wt% or more.

Further, from the comparison between Example 1 and Example 2, it was confirmed that the puncture strength was improved by increasing the addition amount of the cellulose nanofibers.

Further, in Example 3 in which esterification and etherification were performed as hydrophobicization, the degree of chemical modification (acid value) was high, and improvement in puncture strength was observed.

Further, as in Example 4, when a surfactant was added to the dispersion liquid, an improvement in puncture strength was observed. It is presumed that the addition of the surfactant caused the liquid paraffin to permeate into the crystalline cellulose, thereby improving the defibration property and the dispersed state in the kneaded product.

Further, from the SEM photographs of the separators shown in FIGS. 4 to 9, better separators than Comparative Example A could be produced in Examples 1 to 3, and they were inferior to Comparative Examples B and C. It can be confirmed that no separator can be manufactured.

(Embodiment 2)
[Device configuration]
In the present embodiment, a manufacturing apparatus (manufacturing system) suitable for use in the method for manufacturing a separator will be described.

FIG. 10 is a schematic view showing the configuration of the manufacturing apparatus (system) of the present embodiment.

S1 is a twin-screw kneading extruder, S2 is a T die, S3 is a raw fabric cooling device (CAST device), S4 is a longitudinal stretching device (MD device), S5 is a first transverse stretching device (first TD device), and S6 is an extraction device. The tank, S7 is a second transverse stretching device (second TD device), and S8 is a winding device.

The twin-screw kneading extruder S1 is a device that melt-kneads the charged raw materials with a shaft having two screws that mesh with each other (see FIG. 11) and pushes them out to the T-die S2.

The T-die S2 is a device that discharges the molten resin extruded from the twin-screw kneading extruder S1 from the slit to the raw fabric cooling device S3.

The raw fabric cooling device S3 is a device that cools the molten resin discharged from the T-die S2 to form a thin film of the molten resin.

The longitudinal stretching device (MD device) S4 is a device that stretches the thin film conveyed from the raw fabric cooling device S3 with a plurality of rolls in the longitudinal direction (MD direction, conveying direction).

The first transverse stretching device (first TD device) S5 is a device that stretches a thin film stretched in the longitudinal direction by the longitudinal stretching device (MD device) S4 in the lateral direction (the direction intersecting the TD direction and the transport direction). ..

The extraction tank S6 is an apparatus for immersing a thin film stretched in the vertical direction and the horizontal direction in an organic solvent to remove unnecessary substances in the film.

The second transverse stretching device (second TD device) S7 is a device that further stretches the thin film treated by the extraction tank S6 in the lateral direction (the direction intersecting the TD direction and the transport direction). In this second transverse stretching device (second TD device) S7, the organic solvent on the surface of the thin film may be volatilized, the thin film may be dried, and heat-fixed.

The winding device S8 is a device that winds the thin film conveyed from the second transverse stretching device (second TD device) S7.

11 and 12 are cross-sectional views showing the configuration of a twin-screw kneading extruder. FIG. 11 corresponds to a cross section along AA of FIG. 10, and FIG. 12 corresponds to a cross section along BB of FIG. As shown in FIG. 11, the twin-screw kneading extruder has shafts 13a and 13b having two screws rotatably inserted and built in the cylinder 12. The screws of the two shafts 13a and 13b are arranged so as to mesh with each other and rotate. The screw consists of multiple screw pieces. FIG. 13 is a perspective view showing a shape example of a screw (screw piece). FIG. 13 (a) is a full flight screw, and FIG. 13 (b) is a kneading disc. The full flight screw has an acute angle at the tip of the screw, and a space is created between the full flight screw and the inner wall of the cylinder 12. On the other hand, the kneading disc has a flat screw tip, a major axis close to the inner diameter of the cylinder 12, and a small gap between the kneading disk and the inner wall of the cylinder 12. It is preferable to use a kneading disc for the kneading portion.

The cylinder 12 has a plurality of processing units (Ta to Tf) on the downstream side where the raw material is kneaded to form a kneaded product and discharged from the upstream side where the raw material is charged. The plurality of processing units include, for example, a first raw material supply unit Ta, a first material mixing and transportation unit Tb, a kneading unit Tc, a second raw material supply unit Td, a kneading unit Te, and a discharge unit Tf. A temperature control mechanism including a heating mechanism and a cooling mechanism is connected to these parts (processing parts) as needed.

For example, a full flight screw is used for the first raw material supply section Ta and the first material mixing transport section Tb, and a kneading disk is used for the kneading section (Tc, Te). Further, for the second raw material supply unit Td and the discharge unit Tf, for example, a full flight screw is used. In this way, by mixing and kneading the raw materials using the shafts 13a and 13b having two screws arranged so as to mesh with each other and rotating, the retention of the raw materials in the cylinder 12 is suppressed and the kneadability is improved. be able to. For example, in the case of the kneader for batch processing shown in FIGS. 14 (a) and 14 (b), the raw material tends to stay in the vicinity of the inner wall of the container and the kneadability tends to decrease. In particular, when the viscosity of the raw material is low as shown in FIG. 14 (a), the kneading can be performed relatively uniformly, but when the viscosity of the raw material is high as shown in FIG. 14 (b), it is near the inner wall of the container. The raw material stays and the kneadability is lowered. 14 (a) and 14 (b) are cross-sectional views showing the configuration and kneading state of the kneader for batch processing.

In particular, when mixing and kneading while heating, when the kneadability of the raw material, that is, the fluidity of the raw material decreases, the heat conduction efficiency decreases, a temperature gradient occurs inside the kneaded product, and the raw material is burnt. On the other hand, when kneading in the cylinder 12 using a screw, the kneading property is improved, the fluidity of the raw material is improved, and uniform kneading and heating are possible. Further, by using the shafts 13a and 13b having two screws arranged so as to mesh with each other and rotating, the screws of both shafts rotate so as to wipe each other (self-cleaning, see FIG. 12). Retention can be further suppressed, and kneadability and uniformity of heating temperature can be improved. The rotation direction of the screw may be the same direction or different directions.

FIG. 15 is a perspective view of the first transverse stretching device (first TD device) S5. As shown in FIG. 15, the first transverse stretching device (first TD device) S5 has a clip chain 5b having a plurality of clips 5c. The clip chain 5b is arranged on the guide rail 5a and is rotated by a guide gear (not shown). 16 (a) to 16 (c) are cross-sectional views showing a schematic configuration of a clip and its operation. As shown in FIGS. 16A to 16C, the control unit 50 on the clip lever 56 tilts the clip lever 56, and the grip portion 58 rotates from the bearing portion 55 as a starting point, thereby causing the base. The film F can be gripped by the inner bottom surface of the member 53 and the grip portion 58. Further, the film F can be released from the clip 5c by returning the clip lever 56 in the vertical direction.

The width of the guide rail 5a increases in the downstream direction, and the film F can be stretched by moving in a direction away from each other while gripping the film F between the pair of opposing clips 5c.

Here, in the longitudinal stretching device S4 having a plurality of rolls, the stretching in the longitudinal direction (MD direction) is performed, and then the stretching in the horizontal direction (TD direction) is performed (sequential stretching), but the longitudinal direction and the horizontal direction are performed. Stretching in the directions may be performed at the same time (simultaneous stretching, see FIG. 3). According to the sequential stretching, continuous processing is easy.

After that, as described above, in the extraction tank S6, the film (thin film) is immersed in an organic solvent to remove unnecessary substances (plasticizers, additives) in the film, and the second transverse stretching device (second TD device) S7. Stretches the film further laterally. Here, in the step of removing the plasticizer (liquid paraffin), as shown in FIG. 10, since the lateral direction (TD direction) is not constrained, the film shrinks in the lateral direction (TD direction). .. Therefore, the second transverse stretching device (second TD device) S7 stretches in the lateral direction (TD direction) at a low magnification to open the fine holes generated by the step of removing unnecessary substances. After that, the residual stress accumulated inside the film during stretching is removed (heat-fixed) by annealing at a temperature slightly higher than the stretching temperature. It is possible to obtain a separator having micropores through which lithium ions can pass. Next, the film is wound up in the winding device S8.

[Manufacturing process of separator using equipment]
The manufacturing process of the separator using the manufacturing apparatus (system) of the present embodiment will be described below.

For example, cellulose nanofibers, an additive (for example, succinic anhydride), and a plasticizer (liquid paraffin) are added to the first raw material supply unit Ta of the twin-screw kneading extruder (S1) shown in FIG. 11, and the first material is mixed. A dispersion liquid is formed by transporting (transporting) while mixing in the transport section Tb and mixing (kneading) in the kneading section Tc. The temperature and treatment time in the kneading portion Tc are, for example, 140 ° C. for 7 minutes. Propylene oxide (PO) or a surfactant may be added to the dispersion liquid.

Next, a polyolefin (for example, polyethylene) is added as a resin material in the second raw material supply unit Td, and the dispersion liquid and the polyolefin are kneaded in the kneading unit Te. The kneading conditions are, for example, 180 ° C. for 12 minutes, and the rotation speed of the shaft is 100 rpm.

The kneaded product (molten resin) is conveyed from the discharge portion Tf to the T die S2, and the molten resin is cooled in the raw fabric cooling device S3 while being extruded from the slit of the T die S2 to form a thin film resin molded body. do.

Next, the thin-film resin molded body is stretched in the vertical direction by the first transverse stretching device (first TD device) S5, and further stretched in the horizontal direction by the first transverse stretching device (first TD device) S5.

Next, the stretched thin film is immersed in an organic solvent (for example, methylene chloride) in the extraction tank S6. In the stretched thin film, the polyolefin (for example, polyethylene) and the plasticizer (paraffin) are in a phase-separated state. Specifically, the plasticizer (paraffin) becomes nano-sized islands. This nano-sized plasticizer (paraffin) is removed (defatted) with an organic solvent (for example, methylene chloride) in the extraction tank S6. This makes it possible to form a porous thin film.

After that, the thin film is further dried and heat-fixed by the second transverse stretching device (second TD device) S7 while stretching in the lateral direction to relieve the internal stress at the time of stretching. The second transverse stretching device (second TD device) S7 can also have the same configuration as the first transverse stretching device (first TD device) S5. Next, the take-up device S8 winds up the thin film conveyed from the second transverse stretching device (second TD device) S7.

In this way, the separator can be manufactured. For example, according to the above apparatus, the separator can be produced at 100 to 200 kg / h.

As described above, by using the manufacturing apparatus of this embodiment, a high-performance separator can be efficiently manufactured.

Further, by continuously processing the raw materials (materials) shown in the first embodiment and the above-mentioned embodiment with the above-mentioned manufacturing apparatus, a high-performance separator can be efficiently manufactured. In particular, in the present embodiment, the steps of removing unreacted additives and drying the chemically modified cellulose can be omitted. Then, in the present embodiment, the efficiency of the manufacturing process of the resin molded product can be improved by continuously treating the preparation of the dispersion liquid and the kneading of the resin and the dispersion liquid.

(Application example)
(1) In FIG. 11, a twin-screw kneading extruder has been described as an example, but a single-screw kneading extruder or a multi-screw kneading extruder having two or more shafts may be used.

(2) In FIG. 1, a sequential stretching device is used, but a simultaneous stretching device may be used. Further, even if a thin film is formed only by stretching in the longitudinal direction (MD direction), the plasticizer (paraffin) is removed by an organic solvent (for example, methylene chloride) in the extraction tank S6, and heat-fixed to form a separator. good.

(3) The dispersion liquid may be adjusted by another mixing device (kneading device) and charged into a twin-screw kneading extruder as a raw material. In this case, in FIG. 11, the first raw material supply section Ta, the first material mixing and transport section Tb, and the kneading section Tc may be omitted, and the dispersion liquid and the resin may be charged into the second raw material supply section Td.

(4) In FIG. 11, the configuration and combination of each processing unit (Ta to Tf) can be changed as appropriate. Further, the screw to be used is not limited to the shape shown in FIG. 13, and can be appropriately changed according to the viscosity of the raw material to be added.

(5) The structure of the clip of the stretching device is not limited to that shown in FIG. 16, and a clip having a structure different from that shown in FIG. 16 may be used as long as the film F can be gripped.

Although the invention made by the present inventor has been specifically described above based on the embodiments and examples, the present invention is not limited to the above embodiments or examples and does not deviate from the gist thereof. Needless to say, it can be changed in various ways.

For example, various changes can be made as in the above application example.

5a Guide rail 5b Clip chain 5c Clip 12 Cylinder 13a Axis (axis with screw)
13b axis (axis with screw)
50 Control unit 53 Base member 55 Bearing part 56 Clip lever 58 Grip part F Film S1 Biaxial kneading extruder S2 T die S3 Raw fabric cooling device (CAST device)
S4 longitudinal stretching device (MD device)
S5 1st transverse stretching device (1st TD device)
S6 Extraction tank S7 Second transverse stretching device (second TD device)
S8 Winding device Ta 1st raw material supply part Tb 1st material mixed transportation part Tc kneading part Td 2nd raw material supply part Te kneading part Tf discharge part

Claims (16)

(A) A step of forming a first mixture by mixing powdered cellulose, an additive and a plasticizer.
(B) A step of forming a kneaded product by kneading the first mixture and polyolefin.
(C) A step of forming a film by stretching the kneaded product,
(D) A step of bringing the film into contact with an organic solvent,
Have a,
In the step (a), the hydrophilic group of the cellulose is replaced with a hydrophobic group by the esterification reaction and / or the etherification reaction of the cellulose and the additive.
The cellulose in the first mixture is 0.01 wt% or more and 30 wt% or less, the additive is 0.01 wt% or more and 50 wt% or less, and the plasticizer is 0.01 wt% or more and 99 wt% or less . A method for producing a cellulose-containing porous resin molded product. In the method for producing a cellulose-containing porous resin molded product according to claim 1.
A method for producing a cellulose-containing porous resin molded product, wherein in the step (d), the plasticizer and the unreacted additive in the step (a) are extracted and removed in the organic solvent. In the method for producing a cellulose-containing porous resin molded product according to claim 1.
The esterification reaction between the cellulose and the additive is a reaction of substituting the hydroxyl group (-OH) of the cellulose with a group having an -O-CO- portion, which is a method for producing a cellulose-containing porous resin molded product. .. In the method for producing a cellulose-containing porous resin molded product according to claim 1.
A method for producing a cellulose-containing porous resin molded product, wherein the etherification reaction between the cellulose and the additive is a reaction in which a hydroxyl group (−OH) of the cellulose is an ether bond. In the method for producing a cellulose-containing porous resin molded product according to claim 3.
The additive is a method for producing a cellulose-containing porous resin molded product, which is a carboxylic acid compound. In the method for producing a cellulose-containing porous resin molded product according to claim 1.
A method for producing a cellulose-containing porous resin molded product, wherein the additive is either ethylene oxide or propylene oxide, or a carboxylic acid-based compound. In the method for producing a cellulose-containing porous resin molded product according to claim 1.
A method for producing a cellulose-containing porous resin molded product, wherein the additive is either ethylene oxide or propylene oxide, and a carboxylic acid-based compound. In the method for producing a cellulose-containing porous resin molded product according to claim 1.
The particle shape of the powdered cellulose is a cellulose-containing porous resin having a diameter of 0.001 μm or more and 50 μm or less, a length of 0.5 μm or more and 10 μm or less, and an aspect ratio (length / diameter) of 100 or more and 1000000 or less. A method for manufacturing a molded product. In the method for producing a cellulose-containing porous resin molded product according to claim 1.
A method for producing a cellulose-containing porous resin molded product, in which a surfactant is further added in the step (a). In the method for producing a cellulose-containing porous resin molded product according to claim 9.
The surfactant is a method for producing a cellulose-containing porous resin molded product, wherein the measured value of surface tension by the Wilhelmy method is 10 or more and 70 or less, and the contact angle is 30 ° or more and 95 ° or less. In the method for producing a cellulose-containing porous resin molded product according to claim 1.
A method for producing a cellulose-containing porous resin molded product, wherein the plasticizer is an organic solvent having a molecular weight of 100 or more and 1500 or less and a boiling point of 50 ° C. or more and less than 300 ° C. In the method for producing a cellulose-containing porous resin molded product according to claim 11.
The plasticizers include liquid paraffin, nonane, decane, decalin, paraxylene, undecane, chain or cyclic aliphatic hydrocarbons of dodecane, mineral oil distillates having corresponding boiling points, and dibutylphthalate and dioctylphthalate. A method for producing a cellulose-containing porous resin molded product, which is a mixture of one or several of phthalates, alcohols, nitrogen-based organic solvents, ketones, and esters that are liquid at room temperature. (A) A step of adding a dispersion liquid and a polyolefin to the kneading extruder of a manufacturing apparatus having a kneading extruder and a stretching machine and kneading them to form a kneaded product.
(B) A step of forming a film by stretching the kneaded product with the stretching machine.
Have,
The dispersion state, and are a mixture of the powdered cellulose additive and a plasticizer,
In the step (a), the hydrophilic group of the cellulose is replaced with a hydrophobic group by the esterification reaction and / or the etherification reaction of the cellulose and the additive.
The cellulose in the dispersion is 0.01 wt% or more and 30 wt% or less, the additive is 0.01 wt% or more and 50 wt% or less, and the plasticizer is 0.01 wt% or more and 99 wt% or less. A method for producing a contained porous resin molded body. In the method for producing a cellulose-containing porous resin molded product according to claim 13.
After the step (b), the plasticizer and the unreacted additive in the step (a) are extracted and removed from the organic solvent by bringing the film into contact with the organic solvent. A method for manufacturing a quality resin molded product. In the method for producing a cellulose-containing porous resin molded product according to claim 13.
In the step (a), the powdered cellulose, the additive, and the plasticizer are mixed in the first treatment section of the kneading extruder, and the second treatment section connected to the first treatment section is used. A method for producing a cellulose-containing porous resin molded product, in which polyolefin and the dispersion are kneaded. (A) In the first processing section of the kneading extruder of the manufacturing apparatus having a kneading extruder, a stretching machine and an extraction tank, powdered cellulose, an additive and a plasticizer are mixed to prepare a dispersion liquid, and the dispersion liquid is prepared. A step of forming a kneaded product by kneading a polyolefin and a dispersion in a second treatment section connected to the first treatment section.
(B) A step of forming a film by stretching the kneaded product with the stretching machine.
(C) A step of bringing the membrane into contact with an organic solvent by the extraction tank.
Have a,
In the step (a), the hydrophilic group of the cellulose is replaced with a hydrophobic group by the esterification reaction and / or the etherification reaction of the cellulose and the additive.
The cellulose in the dispersion is 0.01 wt% or more and 30 wt% or less, the additive is 0.01 wt% or more and 50 wt% or less, and the plasticizer is 0.01 wt% or more and 99 wt% or less. A method for producing a contained porous resin molded body.

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