JP6541086B1 - Method for producing molded articles of polymer substance - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing a high-molecular-weight polymer molded article which can be molded in a dry state, thereby reducing the amount of waste liquid generated by production, having high orientation and strength, and excellent in taskness. To do. SOLUTION: An extrusion process of extruding a mixed solution containing a polymer substance, an ionic liquid, and a solvent from a discharge port into a gas phase, and a solvent contained in the mixed solution extruded into the gas phase in a gas phase A method for producing a high-polymer substance molded body, comprising: a solidifying step of obtaining a solid body containing a polymer substance and an ionic liquid by vaporization; and a heating and drawing step of heating and drawing the solid body in a gas phase. provide. 【Selection chart】 None

Description

  The present invention relates to a method for producing a high-molecular-weight polymer molded article which can be molded in a dry state, thereby reducing the amount of waste liquid generated by production, having high orientation and strength, and excellent in taskness. .

  As a solvent used when performing molding processing using a protein as a raw material, trifluoroethanol, tetrahydrofuran, hexafluoroisopropanol (HFIP), trifluoroacetic acid, formic acid, water, dimethylformamide and the like are known (for example, Non-Patent Document 1) reference). Among them, hexafluoroisopropanol is used in a process for producing a silk-made artificial fiber, since it dissolves refined silk fibroin well and is highly volatile (see, for example, Patent Document 1).

  However, the molded product obtained by volatilizing the solvent from the silk fibroin solution or removing the solvent in the coagulation bath has low flexibility and elongation, lacks processability, and it is difficult to improve the strength and elongation by drawing. Yes, so the strength was not sufficient.

U.S. Pat. No. 5,252,285

D. B. Khadka, D. T. Haynie, Nanomedicine: Nanotechnology, Biology, and Medicine, 8, 1242-1262 (2012)

  The present invention has been made in view of such circumstances, and the object thereof is to enable dry molding, thereby reducing the amount of waste solution generated by production, and having high orientation and strength and elongation, It is an object of the present invention to provide a method for producing a molded article of a polymeric substance excellent in taskness.

  As a result of intensive studies to achieve the above object, the inventors of the present invention have found that when using a mixed solution containing a polymer substance, an ionic liquid, and a solvent when producing a polymer substance molding, A solid body containing a polymer substance and an ionic liquid, which is obtained by extruding into a phase and vaporizing a solvent in a gas phase, is excellent in flexibility and elongation, and further, such a polymer substance and It has been found that by stretching a solidified body containing an ionic liquid, it is possible to obtain a polymer substance molded article having high orientation and high elongation and excellent in taskness, and the present invention has been completed.

That is, the present invention relates to the following matters.
[1] An extrusion step of extruding a mixed solution containing a polymer substance, an ionic liquid, and a solvent from a discharge port into a gas phase,
Solidifying the solvent contained in the mixed solution extruded into the gas phase by vaporizing the solvent in the gas phase to obtain a solidified body containing the polymer substance and the ionic liquid;
And a heating and drawing step of heating and drawing the solidified body in a gas phase.

[2] The method for producing a molded polymer material according to [1], further including an ionic liquid removing step of removing an ionic liquid contained in the solidified body after being drawn by the heat drawing step.
[3] In the ionic liquid removing step, the ionic liquid is removed so that the content of the ionic liquid contained in the solidified body is 1% by weight or less with respect to the entire stretched body. The manufacturing method of the polymeric substance molded object as described in [2].
[4] The polymeric substance according to [2] or [3], wherein the removal of the ionic liquid in the ionic liquid removing step is performed by immersing the solidified body after drawing in a good solvent of the ionic liquid How to make the body.
[5] The method for producing a molded article of polymer substance according to any one of [1] to [4], wherein two or more kinds of polymer substances are used as the polymer substance.

[6] The solvent according to any one of [1] to [5], wherein a solvent having a boiling point of 300 ° C. or less and capable of dissolving 1% by weight or more of the polymer substance and the ionic liquid is used. A method of producing a molecular substance molding.
[7] The method for producing a molded article of polymer substance according to any one of [1] to [6], wherein the polymer substance is a protein.
[8] The method for producing a molded article of macromolecular substance according to [7], wherein the protein is a structural protein.
[9] The method for producing a molded high-molecular-weight material according to [7] or [8], wherein the protein is fibroin.
[10] The method for producing a high-polymer substance molded article according to any one of [7] to [9], wherein the protein is silk fibroin.

[11] The polymer liquid molded article according to any one of [1] to [10], wherein the ionic liquid has a melting point of less than 100 ° C. and a heating weight reduction rate of 10% by mass and a temperature of 200 ° C. or higher. Production method.
[12] The method for producing a molded polymer material according to any one of [1] to [11], wherein the ionic liquid contains an imidazolium structure-containing cation.
[13] The method for producing a molded polymer material according to [12], wherein the imidazolium structure-containing cation is 1-hexyl-3-methylimidazolium cation.
[14] The method for producing a molded article of polymer substance according to [13], wherein the ionic liquid is 1-hexyl-3-methylimidazolium chloride.
[15] The method for producing a molded article of polymer substance according to any one of [1] to [14], wherein the solvent is hexafluoroisopropanol.

[16] The method for producing a molded polymer material according to any one of [1] to [15], wherein the stretching ratio in the heating and drawing step is three or more.
[17] In the extrusion step, the mixed solution is continuously extruded from the discharge port into the gas phase,
In the solidifying step, a solvent contained in the mixed solution extruded continuously is vaporized in a gas phase to continuously obtain the solid,
In the heating and drawing step, the polymer substance molded body according to any one of [1] to [16], wherein a fibrous polymer substance molded body is obtained by drawing the solidified body obtained continuously. Manufacturing method.

  According to the present invention, it is possible to perform dry molding, thereby reducing the amount of waste liquid generated by production, and producing a molded product of polymer substance having high orientation, high elongation, and excellent taskness. We can provide a way.

FIG. 1 is a view showing an example of a spinning apparatus according to an embodiment of the present invention. FIG. 2 is a view showing stress-strain curves of Examples 1 and 2 and Comparative Examples 1 and 2. FIG. 3 (A) is a polarized light microscope photograph of the heat drawn yarn (without methanol washing) obtained in Example 1, and FIG. 3 (B) is the undrawn yarn obtained in Reference Example 1 (without methanol washing) Polarization photomicrograph of FIG. 4 (A) is an electron micrograph of the side of the heat drawn yarn (without methanol washing) obtained in Example 1, and FIG. 4 (B) is the heat drawn yarn obtained in Example 1 (methanol 6 is an electron micrograph of a cross section of (without washing). FIG. 5 (A) is an electron micrograph of the side of the thermally drawn yarn (with methanol washing) obtained in Example 2, and FIG. 5 (B) is the thermally drawn yarn obtained in Example 2 (methanol) 6 is an electron micrograph of the cross section of “with washing”. FIG. 6 is an X-ray spectrum (EDX spectrum) extracted from the cross section of the heat drawn yarn (without methanol washing) obtained in Example 1. Fig. 7 (A) is an EDX visual field image of a cross section of the heat drawn yarn (without methanol washing) obtained in Example 1, and Fig. 7 (B) is a chlorine signal in the cross section shown in Fig. 7 (A). It is an elemental mapping image focused on. FIG. 8 is an X-ray spectrum (EDX spectrum) extracted from the cross section of the heat drawn yarn (with methanol washing) obtained in Example 2. Fig. 9 (A) is an EDX visual field image of a cross section of the heat drawn yarn (with methanol washing) obtained in Example 2, and Fig. 9 (B) is a chlorine signal in the cross section shown in Fig. 9 (A). It is an elemental mapping image focused on.

The method for producing a polymeric substance molded article of the present invention is
Extruding the mixture solution containing the polymer substance, the ionic liquid, and the solvent from the discharge port into the gas phase;
Solidifying the solvent contained in the mixed solution extruded into the gas phase by vaporizing the solvent in the gas phase to obtain a solidified body containing the polymer substance and the ionic liquid;
And e) heating and stretching the solidified body in a gas phase.

  The polymer substance used in the present invention may be a polymer substance and is not particularly limited, and examples include proteins, polysaccharides, synthetic polymers, and the like. These high molecular substances may be used alone or in combination of two or more.

  Examples of proteins include recombinant proteins having a molecular weight of 5,000 daltons or more, fusion proteins, recombinant proteins, structural proteins, functional proteins, and man-made structural proteins derived from these proteins. Among these, structural proteins, functional proteins, and structural proteins, and man-made structural proteins derived from functional proteins are preferable, and structural proteins are more preferable. The functional protein is a protein having physiological activity, and includes bovine serum albumin, immunoglobulin and the like, with bovine serum albumin being preferred. The structural protein is a protein which forms or retains the structure, form and the like in the living body, and examples of the structural protein include fibroin, keratin, collagen, elastin and resilin etc. Fibrone is preferred from the viewpoint of obtaining a more excellent molded article by the strength and elongation.

  Examples of fibroin include silk fibroin, spider silk fibroin, hornet silk fibroin and the like, and these may be used in combination. For example, when silk fibroin and spider silk fibroin are used in combination, the ratio of silk fibroin is, for example, preferably 40 parts by mass or less, more preferably 30 parts by mass or less, more preferably 100 parts by mass of spider silk fibroin. It is 10 parts by mass or less.

  The silk fibroin may be sericin-removed silk fibroin, sericin-unremoved silk fibroin, or a combination thereof. The sericin-removed silk fibroin is purified by removing sericin covering silk fibroin and other fats and the like. The silk fibroin thus purified is preferably used as a lyophilised powder. Sericin non-removed silk fibroin is crude silk fibroin from which sericin etc. is not removed.

  The spider silk fibroin may contain a spider silk polypeptide selected from the group consisting of natural spider silk proteins and polypeptides derived from natural spider silk proteins (human spider silk proteins).

  The term "derived from natural spider silk protein" refers to one having an amino acid sequence similar to or similar to the repetitive sequence of amino acids possessed by natural spider silk proteins, for example, mutations of recombinant spider silk proteins and natural spider silk proteins Body, analogue or derivative etc. are mentioned. The spider silk protein is preferably a large nasogastric dragline protein produced in a large glandular gland of a spider or a spider silk protein derived therefrom. Examples of the large nasogastric silkworm silk proteins include the major ampullate spidroins MaSp1 and MaSp2 derived from Nephila clavipes, and the ADF3 and ADF4 derived from the spider spider (Araneus diadematus).

  The spider silk protein may be a small nasogastric dragline protein produced in a small gland of a spider or a spider silk protein derived therefrom. As the small nasogastric silkworm silk proteins, there may be mentioned the vesicular gland spidroin MiSp1 or MiSp2 derived from Nephila clavipes.

  Alternatively, the spider silk protein may be a weft protein produced in the flagelliform gland of a spider or a spider silk protein derived therefrom. Examples of the weft protein include flagelliform silk protein derived from Nephila clavipes.

  The polysaccharide is not particularly limited, and examples thereof include cellulose, hemicellulose, glycogen, starch, chitin, chitosan, agarose, carrageenan and the like.

  The synthetic polymer may be any of synthetic polymers obtained by polycondensation reaction, synthetic polymers obtained by chain polymerization, and other synthetic polymers, and is not particularly limited. Acrylic polymer, methacrylic polymer, carboxylic acid vinyl ester polymer, poly-N-vinyl compound polymer, polyolefin polymer, polydiene polymer, polyester polymer, silicone polymer, polyurethane Examples thereof include system polymers, polyamide polymers, polyimide polymers, epoxy polymers, polyvinyl butyral polymers, phenol polymers, amino polymers, oxazoline polymers, and carbodiimide polymers.

  The ionic liquid may be an organic salt which is liquid at less than 100 ° C., and is not particularly limited. Examples thereof include imidazolium, pyrrolidinium, piperidinium, pyridinium, quaternary ammonium, quaternary phosphonium, sulfonium, and the like. Mention may be made of salts of cations such as derivatives and anions such as halogen, triflate, tetrafluoroborate and hexafluorophosphate. Among these, imidazolium salts containing an imidazolium structure-containing cation such as an imidazolium cation are preferable from the viewpoint of compatibility with the polymer substance.

  Examples of the imidazolium salt include 1,3-dimethylimidazolium salt, 1-ethyl-3-methylimidazolium salt, 1-methyl-3-propylimidazolium salt, 1-butyl-3-methylimidazolium salt, 1-Hexyl-3-methylimidazolium salt, 1-methyl-3-n-octylimidazolium salt, 1- (2-hydroxyethyl) -3-methylimidazolium salt, 1-decyl-3-methylimidazolium salt 1-ethyl-2,3-dimethylimidazolium salt, 1,2-dimethyl-3-propylimidazolium salt, 2,3-dimethyl-1-propylimidazolium salt, 1-butyl-2,3-dimethylimidazo Lithium salts, 1-hexyl-2,3-dimethylimidazolium salts and the like, and among these, 1-ethyl-3-methyl Imidazolium salt, 1-butyl-3-methylimidazolium salt, 1-hexyl-3-methylimidazolium salts are preferred, 1-hexyl-3-methylimidazolium salt is more preferable.

For example, various cations,
[Emim] 1-ethyl-3-methylimidazolium ion
[Bmim] 1-butyl-3-methylimidazolium ion
[Hmim] 1-hexyl-3-methylimidazolium ion
[Omim] 1-methyl-3-octylimidazolium ion
[Dmim] 1-decyl-3-methylimidazolium ion Various anions,
[Cl] chloride ion
[Ac] acetate ion
[DMP] dimethyl phosphate ion
[DEP] Diethyl phosphate ion
[TfO] trifluoromethanesulfonate ion
[TFSI] When it is referred to as bis (trifluoromethanesulfonyl) imide ion, examples of the ionic liquid include those shown below.
[Emim] [Cl], [Bmim] [Cl], [Hmim] [Cl], [Omim] [Cl], [Dmim] [Cl]
[Emim] [Ac], [Bmim] [Ac], [Hmim] [Ac], [Omim] [Ac], [Dmim] [Ac]
[Emim] [DMP], [Bmim] [DMP], [Hmim] [DMP], [Omim] [DMP], [Dmim] [DMP]
[Emim] [DEP], [Bmim] [DEP], [Hmim] [DEP], [Omim] [DEP], [Dmim] [DEP]
[Emim] [TfO], [Bmim] [TfO], [Hmim] [TfO], [Omim] [TfO], [Dmim] [TfO]
[Emim] [TFSI], [Bmim] [TFSI], [Hmim] [TFSI], [Omim] [TFSI], [Dmim] [TFSI]
Among these, 1-hexyl 3-methyl imidazolium chloride ([Hmim] [Cl]) is used suitably.

  The ionic liquid is preferably one having a melting point of less than 100 ° C. and a heating weight reduction rate of 10% by mass at a temperature of 200 ° C. or more, and a melting point of less than 60 ° C., a heating weight reduction rate of 10% by mass More preferably, the temperature is 250 ° C. or higher. The heating weight reduction rate is a value calculated from the weight change from the start of heating when the ionic liquid is heated to a temperature of 50 to 500 ° C. at a quasistatic rate (5 ° C./min). As the ionic liquid, it is preferable to use one that dissolves 5% by weight or more of the polymer substance to be used, and more preferable to use one that dissolves 7% by weight or more.

  The solvent is not particularly limited, but preferred is one having a boiling point of 300 ° C. or less and capable of dissolving 1% by weight or more of the polymer substance and the ionic liquid, for example, hexafluoroisopropanol and hexafluoroacetone. And hexafluoroisopropanol are particularly preferred.

  Next, the method for producing the polymeric substance molded article of the present invention will be described in detail. In the present invention, the polymeric substance molded body can be produced, for example, using a spinning apparatus according to an embodiment of the present invention shown in FIG. The following description will be made centering on the manufacturing method using the spinning apparatus shown in FIG. 1, but the method of manufacturing the polymeric substance molded article of the present invention is particularly applicable to the manufacturing method using the spinning apparatus shown in FIG. It is not limited.

In the production method of the present invention,
First, a mixed solution containing the above-described polymer substance, ionic liquid, and solvent is extruded from the discharge port into the gas phase (extrusion process),
Next, the solvent contained in the mixed solution extruded into the gas phase is vaporized in the gas phase to obtain a solidified body containing the polymer substance and the ionic liquid (solidification step).
And a polymeric substance molded object can be obtained by carrying out the heating extending | stretching of the obtained solidified body in a gaseous phase (heating extending process).

  The extrusion step and the solidification step in the production method of the present invention can be performed, for example, using a spinning apparatus shown in FIG. The spinning apparatus shown in FIG. 1 has a reservoir 10, in which a mixed solution 20 containing a polymer substance, an ionic liquid, and a solvent is stored. Then, according to the spinning apparatus shown in FIG. 1, the mixed solution 20 is continuously pushed out into the gas phase from the nozzle 40 having a discharge port at the tip by the gear pump 30 attached to the lower end of the storage tank 10 . Then, the extruded mixed solution 20 falls toward the winder 60 by gravity, and the solvent contained in the mixed solution 20 evaporates in the gas phase to become a fibrous solidified body, and the winder 60 It is taken up by. The solidified body taken up by the winder 60 contains a polymer substance and an ionic liquid.

  Then, by subjecting the fibrous solidified body wound up by the winder 60 to heat drawing, a polymer substance molded body can be obtained. Although it does not specifically limit as a method of extending | stretching, Uniaxial stretching is suitable.

  The method of preparing the mixed solution 20 is not particularly limited, and a method of mixing a polymer substance, an ionic liquid, and a solvent in a mixing apparatus, and the like can be mentioned. In this case, from the viewpoint of the mixing property, it is preferable to add the ionic liquid after first mixing the polymer substance and the solvent.

The content ratio of the polymer substance in the mixed solution 20 is preferably more than 5% by weight and 30% by weight or less, more preferably 7% by weight to 25% by weight, and still more preferably 10% by weight to 18% by weight.
The content ratio of the ionic liquid in the mixed solution 20 is preferably more than 0 parts by weight and 100 parts by weight or less, preferably 1 to 50 parts by weight, and more preferably 12 to 100 parts by weight of the polymer substance. It is 25 parts by weight.

  The nozzle 40 and the discharge port provided at the tip thereof are not particularly limited and may be appropriately selected according to the shape and size of the polymeric substance molded body to be produced. For example, the discharge port is a multihole discharge port It may be Moreover, the internal diameter of the nozzle 40 is preferably 0.1 to 0.6 mm, more preferably 0.15 to 0.3 mm.

  Further, in the present embodiment, when continuously extruding the mixed solution 20 from the nozzle 40, a method of evaporating the solvent in the gas phase while using the method in which the solvent is evaporated in the gas phase, that is, a dry spinning method is adopted. It is. The gas phase is not particularly limited, and may be in air, in an inert gas, or in a non-oxidizing atmosphere. In addition, when the solvent is evaporated in the gas phase, a method of blowing hot air, a method of heating, or the like may be adopted as needed. According to this embodiment, since the dry spinning method is used, the amount of waste liquid can be reduced as compared with the dry-wet spinning method or the wet spinning method, whereby the environmental load can be reduced. Since the manufacturing process can be simplified, the production efficiency can be enhanced.

  The distance D from the discharge port of the nozzle 40 to the winder 60 is such that the solvent contained in the mixed solution 20 extruded from the discharge port of the nozzle 40 is sufficiently evaporated so that the film can be wound by the winder 60. The length may be set to be a solidified body, but it is usually about 50 cm to 5 m. Further, in the present embodiment, the solidified body after evaporation of the solvent may be one that does not substantially contain the solvent, or if it is about several weight%, the solvent remains. May be

  In the present embodiment, it is preferable that the mixed solution 20 extruded from the discharge port of the nozzle 40 flow down according to gravity, and by using such an embodiment, the flow orientation of the polymer substance is reduced. As a result, crystal orientation can be promoted, whereby the resulting molded product of macromolecular substance can have higher orientation and strength and elongation.

  Next, in the present embodiment, the stretched body obtained in this manner is subjected to heat drawing. The solidified body obtained in the present embodiment is obtained by a dry spinning method, and contains a polymer substance and an ionic liquid. And since the solidified body thus obtained by the dry spinning method is obtained by evaporating the solvent in the gas phase, the ionic liquid should be uniformly distributed as a plasticizer inside the polymer substance. It is possible to

  Therefore, according to the present embodiment, when the solidified body is heated and stretched, the polymer substance contained in the solidified body can be brought into a molten state using the ionic liquid as a plasticizer, and in such a molten state It enables stretching. In particular, according to the present embodiment, at the time of heat drawing, relaxation of the polymer chain can be caused while preventing micro structure destruction in the solidified body to be subjected to the heat drawing by the action of the ionic liquid. By performing stretching in such a state, the molecular orientation of polymer chains can be effectively enhanced. As a result, it is possible to obtain a molded article of the macromolecular substance which is high in orientation and strength and elongation and excellent in taskness. In addition, although it is not necessarily clear as a reason which can suppress micro structure destruction in the solidification object which is provided to heating extension by the action of an ionic liquid, an ionic liquid intervenes between polymer molecular chains, and adjacent polymers It is considered that the relaxation of the polymer molecular chain can be caused while appropriately maintaining the interaction between the molecular chains.

The heating temperature at the time of heating and drawing is not particularly limited, but is preferably a temperature higher than the glass transition temperature (Tg) of the polymer substance and the ionic liquid used, preferably 40 ° C. or more, more preferably 100 C. or higher, more preferably 120.degree. C. or higher. The upper limit of the heating temperature is not particularly limited, but is usually 160 ° C. or less. Moreover, the stretching ratio at the time of heat drawing is preferably 3 times or more, more preferably 3.5 times or more, and the upper limit thereof is usually 10 times or less. The heating and stretching method is not particularly limited. For example, while applying tension in the longitudinal direction to the fiber-like solidified body taken up by the winder 60 (unwinding side) while heating, another method may be used. The fiber-like solidified body can be stretched by being wound up on a winder (winding side), and the draw ratio in this case can be controlled and calculated according to the following equation, for example.
Stretching ratio = winding speed / unwinding speed

  Thus, according to the present embodiment, it is possible to obtain a fibrous polymeric substance molded body. According to the present embodiment, dry molding is possible, thereby reducing the amount of waste liquid generated by manufacturing, and further, since stretching under heating can be favorably performed, it is obtained. It is possible to make the fibrous high-molecular-weight material molded body high in orientation and strength and elongation and excellent in taskness.

  In the present embodiment, the polymer liquid molded body (solidified body after stretching) obtained in this manner may be subjected to a treatment for removing the ionic liquid, as necessary. If the ionic liquid remains, depending on the application of the obtained polymeric substance molded body (solidified body after stretching), the exudation of the ionic liquid may be a problem, and in such a case, It is preferable to carry out treatment to remove the ionic liquid. Although it does not specifically limit as a method to remove an ionic liquid, The polymeric substance molded object (solidification body after extending | stretching) is immersed in the good solvent of an ionic liquid, and the method of wash | cleaning is mentioned. The good solvent for the ionic liquid used at this time is not particularly limited and may be appropriately selected according to the type of the ionic liquid used, but for example, polar solvents such as water, methanol, ethanol etc., acetone, methyl ethyl ketone etc. Ketone solvents, alkane organic solvents such as n-hexane and n-heptane, ether solvents such as diethyl ether, tetrahydrofuran and cyclopentyl methyl ether, and aprotic solvents such as dimethyl sulfoxide and N-methyl-2-pyrrolidone Be

  In addition, when removing the ionic liquid, the amount of the ionic liquid remaining in the polymer substance molded body (solidified body after stretching) is preferably 1% by weight or less, more preferably 0.1% by weight or less. It is desirable to carry out the treatment to remove the ionic liquid. The method for setting the amount of the ionic liquid remaining after removal of the ionic liquid to the above range is not particularly limited, but a method of adjusting the immersion time in a good solvent, or 30 in immersion in a good solvent, A method of heating to about 100 ° C. and the like can be mentioned. In addition, in order to promote the elution of the ionic liquid, a method of irradiating an ultrasonic wave and a method of stirring a good solvent during immersion may also be mentioned. Moreover, after performing the operation which removes an ionic liquid, it is preferable to dry as needed.

  In the above, the case of producing the fibrous polymer molded article was described using the spinning apparatus shown in FIG. 1, but the present invention is not particularly limited to such an embodiment. Absent. For example, in the above-described method, the solid body obtained by evaporating the solvent is taken up by the winder 60 and then thermally drawn, as an example. It is good also as an aspect which extends. In addition, the shape of the discharge port is not particularly limited when the mixed solution 20 is extruded from the discharge port provided at the tip of the nozzle 40, and may be a thread-like compact, a string-like compact, a film-like compact, or a tape. It can be made into the shape according to various-shaped molded objects, such as a green molded object and a hollow fiber-shaped molded object.

  EXAMPLES Hereinafter, the present invention will be more specifically described by way of examples, but the present invention is not limited to these examples.

Example 1
(1) Scouring of raw silk Warming 6.5 g of raw silk derived from silkworm in 650 mL of desericin solution (0.25 w / v% Marcel soap, 0.25 w / v% sodium carbonate aqueous solution) at 85 ° C for 20 minutes Washed with The supernatant was discarded, and the same operation was repeated twice more (a total of 3 washing operations). After discarding the supernatant, the resulting fiber was rinsed with a sufficient amount of ultrapure water (80 ° C.) and vacuum dried overnight at room temperature (25 ° C.).
A small amount of 32.9 g of calcium chloride / water / ethanol (1/8/2, mol / mol / mol) mixed solution is added little by little to 4.9 g of the fiber dried in vacuum, and dissolved by heating at 55 ° C. for 1 hour , Obtained silk solution. The obtained silk solution was returned to room temperature, packed in a cellulose dialysis tube (MWCO: 14000 Da), and replaced with ultrapure water (4 days, 4 ° C.). Then, the obtained silk aqueous solution obtained by dialysis was diluted with ultrapure water so as to have a silk concentration of 4 wt% or less, and freeze-dried by a conventional method to obtain refined silk.

(2) Preparation of spinning solution (mixed solution) 16.25 g of hexafluoroisopropanol was added to 3.0 g of scouring silk, heated to 50 ° C., and the scouring silk was dissolved in hexafluoroisopropanol by mixing. . Then, while maintaining the temperature of the obtained solution at 50 ° C., 0.75 g of 1-hexyl-3-methylimidazolium chloride ([Hmim] [Cl]) is added thereto and mixed, thereby spinning A liquid (mixed solution) was obtained.

(3) Dry spinning using spinning solution The spinning solution prepared above is filled in a stainless steel cylinder (made by Musashi Engineering Co., Ltd.) equipped with a disposable needle with an inner diameter of 0.3 mm, and nitrogen pressure is applied to the spinning solution. Was discharged continuously into the air. At this time, as a needle of a discharge port, one to which a fluorine-based release agent was applied in advance was used, and the discharge direction of the spinning solution was directed vertically downward. Specifically, at first, the spinning solution is discharged at a nitrogen pressure of 0.3 MPa, and the dropped yarn is wound around a roller immediately below the cylinder to stabilize the discharge, and then the pressure is set to 0.02 MPa. It was lowered to a continuous discharge operation. In addition, the roller winding speed immediately below the cylinder was reduced from the initial speed of 12.0 m / min to 4.0 m / min. In this operation, the spinning solution discharged from the needle is continuously wound on a roller in a state in which it becomes filamentous from liquid by being evaporated from hexafluoroisopropanol as a solvent in the air. It has become a form to be taken. And after winding 5 times between rollers, it was guide | induced to the winding machine (4.2 m / min) provided with the bobbin, and this was made into the original thread before extending | stretching. The obtained raw yarn before drawing was vacuum-dried at normal temperature (25 ° C.) together with the bobbin (drying time: 5 hours).

(4) Thermal drawing of the raw yarn Using two winders, the raw yarn before drawing obtained above is unwound from one side, and a device system for winding the drawn yarn on the other side is assembled, and the heat drawing operation is performed. The heat drawn yarn was obtained. At this time, a hot plate is disposed between the two winders, the temperature is adjusted to 120 ° C., the speed on the unwinding side is 0.25 m / min, and the speed on the winding side is 0. It was 88 m / min. That is, the stretching ratio was 3.5 times (= 0.88 m / min / 0.25 m / min).

Example 2
In the same manner as Example 1, a heat drawn yarn was obtained. Then, after immersing the obtained thermally drawn yarn in a sufficient amount of methanol for 5 minutes under normal temperature (25 ° C.), it is vacuum dried for 30 minutes at normal temperature (25 ° C.) to obtain 1-hexyl-3-methylimidazolium The heat drawn yarn (with methanol washing) was obtained by removing the chloride ([Hmim] [Cl]).

Reference Example 1
In the same manner as Example 1, an undrawn raw fiber was obtained. In Reference Example 1, the heat drawing was not performed.

Reference Example 2
In the same manner as Example 1, an undrawn raw fiber was obtained. Then, the undrawn raw yarn is immersed in sufficient amount of methanol for 5 minutes under normal temperature (25 ° C.), and then vacuum dried for 30 minutes at normal temperature (25 ° C.) to obtain 1-hexyl-3-methylimidazolium chloride By removing ([Hmim] [Cl]), an undrawn yarn (with methanol washing) was obtained.

Comparative Example 1
Example 1 except that 1-hexyl-3-methylimidazolium chloride ([Hmim] [Cl]) as an ionic liquid was not blended while using the refined silk obtained in the same manner as in Example 1. In the same manner as in the above, a spinning solution (mixed solution) was obtained, and dry spinning was performed similarly to obtain a raw yarn. In addition, when the heat | fever drawing was performed by the method similar to Example 1 about the raw yarn obtained by the comparative example 1, the fracture | rupture of the raw yarn was severe and it was not able to be heat-drawn.

<Tension test>
The thermally drawn yarns obtained in Examples 1 and 2 and the undrawn yarns obtained in Reference Examples 1 and 2 were used, and these were fixed with an adhesive to a test strip of paper having a distance between grips of 20 mm. Then, stress and elongation were measured at a tensile speed of 10 mm / min using an Instron tensile tester INSTRON 5943. At this time, the temperature was maintained at 22 to 27 ° C. and a relative humidity of 26 to 46%. Also, the load cell had a capacity of 500 N, and the grip was a clip type.

The stress-strain curve obtained as a result of the tensile test is shown in FIG.
From FIG. 2, the Young's modulus of Example 2 (with heat drawing, with methanol washing) was 4.83 GPa, the Young's modulus of Example 1 (with heat drawing, without methanol washing) was 5.12 GPa, and the Young's modulus was similar. . Also, at the yield point, Example 2 (with heat drawing, with methanol washing) has a stress of 108 MPa, strain 2.2%, and Example 1 (with heat drawing, without methanol washing) has a stress of 160 MPa, strain 3.6%. Met.
The physical properties of the breaking point are almost the same as Example 2 (with heat drawing and methanol washing) at a stress of 167 MPa, strain 35%, and Example 1 (with heat drawing and methanol washing) at a stress of 170 MPa and strain 30%. there were. The tensile stress of Example 2 (with heat drawing and methanol washing) and Example 1 (without heat drawing and methanol washing) monotonously increases in the section of 5 to 30% of strain, and it is accompanied by the tension during the test. It can be determined that orientation hardening has occurred.

  On the other hand, in Reference Example 2 (not drawn, with methanol washing), Young's modulus is 4.41 GPa, Example 2 (heat drawing, with methanol washing), and Example 1 (heat drawing with no methanol washing). Although it was an extent, it fractured in an elastic region with a breaking stress of 62 MPa and a breaking strain of 1.8%.

  On the other hand, in Reference Example 1 (unstretched, without methanol washing), the tensile stress does not exceed 11 MPa at the maximum, and the breaking strain is 221%, that is, it breaks up to 2.2 times the initial length and breaks. It clearly shows different physical properties.

  The results of Reference Example 2 (unstretched, with methanol washing) and Reference Example 1 (unstretched, without methanol washing) support that the ionic liquid functions as a plasticizer for protein fibers. That is, Reference Example 1 (unstretched, without methanol washing) is an example in which the effect of the plasticizer can be clearly seen, and the presence of the ionic liquid itself does not contribute to the improvement of strength, but contributes greatly to the improvement of elongation. I understand. On the contrary, in Reference Example 2 (unstretched, with methanol washing) in which the ionic liquid is removed by methanol washing, the plasticity is not exhibited and fracture occurs in the elastic region.

  Furthermore, the results of Example 2 (with heat drawing and methanol washing) and Example 1 (with heat drawing and methanol washing) show that the physical properties are comprehensive compared with the unstretched by the heat-heated drawing step in the presence of the ionic liquid. It suggests that it improves. Regarding this, it was thought that relaxation of protein molecular chains occurred in the process of heat drawing, and molecular orientation was enhanced while preventing structural destruction in the fiber. Accordingly, it is considered that the elongation could be maintained even after removing the ionic liquid by methanol washing.

  Further, in both Example 2 (with heat drawing and methanol washing) and Example 1 (without heat drawing and methanol washing), the strain at break exceeds 30%, and it is higher than the strain at break of natural silk (about 20%). It was a big one.

<Calculation of toughness>
The toughness of the heat drawn yarn obtained in Examples 1 and 2 and the undrawn yarn obtained in Reference Examples 1 and 2 was calculated according to the following formula.
In the above formula, W: toughness (MJ / m ³ ), σ: tensile stress: MPa, x: tensile loss (mm / mm).
The toughness value of Example 1 (heat drawing, without methanol washing) is 43.2 MJ / m ³ , and the toughness value of Example 2 (heat drawing, with methanol washing) is 39.4 MJ / m ³ . Yes, the value of toughness of Reference Example 1 (unstretched, without methanol washing) is 10.2 MJ / m ³ , the value of toughness of Reference Example 2 (not stretched, with methanol washing) is 0.7 MJ / m It was ^three .

<Observation of polarization by polarization microscope>
The thermally drawn yarn (without methanol washing) obtained in Example 1 and the undrawn yarn (without methanol washing) obtained in Reference Example 1 are fixed to a slide glass and provided with a polarizer and an analyzer and polarized light made by Olympus Observation was carried out with a microscope Olympus CX 31 with a 10 × eyepiece and a 20 × objective lens (total 200 ×) in the form of a dark background (cross nicol). FIG. 3 (A) is a polarized light microscope photograph of the heat drawn yarn (without methanol washing) obtained in Example 1, and FIG. 3 (B) is the undrawn yarn obtained in Reference Example 1 (without methanol washing) Polarization photomicrograph of In any case, it can be confirmed that light is transmitted only through the fiber portion to show an interference color. From this, it can be understood that crystal orientation of silk fibroin has already occurred in the process of winding the undrawn yarn by dry spinning. In the dry spinning of the present method, since the discharged spinning solution flows down according to gravity, it is considered that the protein polymer is now fluidly oriented to generate polarization.

<Form observation by scanning electron microscope (SEM)>
The thermally drawn yarn (without methanol washing) obtained in Example 1 was cut with a carbon steel razor and imaged with a scanning electron microscope JSM-7100F manufactured by JEOL. FIG. 4 (A) is an electron micrograph of the side of the heat drawn yarn (without methanol washing) obtained in Example 1, and FIG. 4 (B) is the heat drawn yarn obtained in Example 1 (methanol 6 is an electron micrograph of a cross section of (without washing). It can be understood from FIG. 4 (A) that the side of the fiber is smooth, and from FIG. 4 (B) it is a uniform structure in which the inside of the fiber is closely packed.

  Similarly, the thermally drawn yarn (with methanol washing) obtained in Example 2 was cut with a carbon steel razor and imaged with a scanning electron microscope JSM-7100F manufactured by JEOL. FIG. 5 (A) is an electron micrograph of the side of the thermally drawn yarn (with methanol washing) obtained in Example 2, and FIG. 5 (B) is the thermally drawn yarn obtained in Example 2 (methanol) 6 is an electron micrograph of the cross section of “with washing”. From FIG. 5 (A) and FIG. 5 (B), the state of the side surface and the cross section is almost the same as the thermally drawn yarn (without methanol washing) obtained in Example 1, and affects the shape of the fiber surface by methanol treatment. It can be confirmed that there is no

<Analysis of ionic liquid contained in thermally drawn yarn>
The thermally drawn yarn (without methanol washing) obtained in Example 1 was cut with a carbon steel razor and subjected to elemental analysis with an EDX apparatus attached to a scanning electron microscope JSM-7100F manufactured by JEOL. FIG. 6 is an X-ray spectrum (EDX spectrum) extracted from the cross section of the heat drawn yarn (without methanol washing) obtained in Example 1. In FIG. 6, the vertical axis is the intensity (Counts) of the EDX detector, and the horizontal axis is the energy (keV) of the characteristic X-ray. The Kα line derived from chlorine is observed around 2.6 keV in this spectrum, and this is the chlorine atom of the ionic liquid (1-hexyl-3-methylimidazolium chloride ([Hmim] [Cl])) used in the example. It can be understood that it is a characteristic X-ray derived from. In addition, it is clear that the ionic liquid is generally hardly volatile and almost all of the ionic liquid in the spinning solution remains in the molded body by dry spinning.

<Distribution of ionic liquid contained in heat drawn yarn>
The thermally drawn yarn (without methanol washing) obtained in Example 1 is cut with a carbon steel razor, and chlorine atoms (Kα ray: 2.6 keV) are obtained by an EDX apparatus attached to a scanning electron microscope JSM-7100F manufactured by JEOL. Elemental mapping was performed. Fig. 7 (A) is an EDX visual field image of a cross section of the heat drawn yarn (without methanol washing) obtained in Example 1, and Fig. 7 (B) is a chlorine signal in the cross section shown in Fig. 7 (A). It is an elemental mapping image focused on. According to the elemental mapping image, chlorine atoms of the ionic liquid (1-hexyl-3-methylimidazolium chloride ([Hmim] [Cl])) are uniformly distributed inside the fiber, that is, the ionic liquid is inside the fiber It can be understood that it is uniformly distributed.

<Confirmation of ionic liquid removal by methanol washing>
About the heat drawn yarn (with methanol washing) obtained in Example 2 by the same method as the heat drawn yarn (without methanol washing) obtained in Example 1, attached to the scanning electron microscope JSM-7100F manufactured by JEOL. The measurement with the EDX device confirmed the removal of the ionic liquid by the methanol washing. FIG. 8 is an X-ray spectrum (EDX spectrum) extracted from the cross section of the heat drawn yarn (with methanol washing) obtained in Example 2, and FIG. 9 (A) is the heat drawing obtained in Example 2 It is an EDX visual field image of the cross section of a thread (with methanol washing), and FIG. 9 (B) is an elemental mapping image focusing on the chlorine signal in the cross section shown in FIG. 9 (A). As shown in FIG. 8, the peak of chlorine-derived Kα line can not be confirmed in the vicinity of 2.6 keV, and as shown in FIGS. 9A and 9B, the elemental mapping image of the cross section No chlorine signal was identified. From this result, it can be judged that almost all (less than 0.1% by weight) of the ionic liquid (1-hexyl-3-methylimidazolium chloride ([Hmim] [Cl])) was removed from the fiber by the methanol washing step. .

Claims (17)

Extruding the mixture solution containing the polymer substance, the ionic liquid, and the solvent from the discharge port into the gas phase;
Solidifying the solvent contained in the mixed solution extruded into the gas phase by vaporizing the solvent in the gas phase to obtain a solidified body containing the polymer substance and the ionic liquid;
And a heating and drawing step of heating and drawing the solidified body in a gas phase .
The manufacturing method of the polymeric substance molded object which uses protein as said polymeric substance .   The manufacturing method of the polymeric substance molded object of Claim 1 further equipped with the ionic liquid removal process of removing the ionic liquid contained in the said solidified body after the extending | stretching by the said heat-drawing process.   In the ionic liquid removing step, the ionic liquid is removed so that the content of the ionic liquid contained in the solidified body is 1% by weight or less with respect to the entire solidified body after stretching. The manufacturing method of the polymeric substance molded object as described in-.   The method according to claim 2 or 3, wherein the removal of the ionic liquid in the ionic liquid removing step is performed by immersing the solidified body after stretching in a good solvent of the ionic liquid.   The method according to any one of claims 1 to 4, wherein two or more types of polymer substances are used as the polymer substance.   The molded polymer article according to any one of claims 1 to 5, wherein a solvent having a boiling point of 300 ° C. or less and capable of dissolving 1% by weight or more of the polymer substance and the ionic liquid is used as the solvent. Production method. The method for producing a molded high-molecular-weight material according to any one of claims 1 to 6 , wherein the protein is a structural protein. The method for producing a molded high-molecular-weight material according to any one of claims 1 to 7 , wherein the protein is fibroin. The method for producing a molded high-molecular-weight material according to any one of claims 1 to 8 , wherein the protein is silk fibroin.   The method according to any one of claims 1 to 9, wherein a protein and a polysaccharide are used as the polymer substance.   The method according to any one of claims 1 to 10, wherein the ionic liquid has a melting point of less than 100 ° C and a heating weight reduction rate of 10% by mass, and the temperature is 200 ° C or more.   The method according to any one of claims 1 to 11, wherein the ionic liquid contains an imidazolium structure-containing cation.   The method according to claim 12, wherein the imidazolium structure-containing cation is 1-hexyl-3-methylimidazolium cation.   The method according to claim 13, wherein the ionic liquid is 1-hexyl-3-methylimidazolium chloride.   The method for producing a molded high-polymer substance according to any one of claims 1 to 14, wherein the solvent is hexafluoroisopropanol.   The method according to any one of claims 1 to 15, wherein the draw ratio in the heating and drawing step is 3 or more. In the extrusion step, the mixed solution is continuously extruded from the discharge port into the gas phase,
In the solidifying step, a solvent contained in the mixed solution extruded continuously is vaporized in a gas phase to continuously obtain the solid,
The manufacturing method of the polymeric substance molded object in any one of Claims 1-16 which obtains a fibrous molded object by extending | stretching the said solidified body continuously obtained in the said heat-drawing process.