JP6774273B2 - Manufacturing method of hydrogel fiber - Google Patents

Description

The present invention relates to a method for producing a hydrogel fiber and a method for controlling the fiber diameter thereof.

Hydrogels are widely used in the fields of cosmetics, pharmaceuticals, quasi-drugs, foods, etc. because of their high water retention, structural flexibility, oxygen diffusivity, substance absorption, elasticity, and biocompatibility. ing. Further, unlike the hydrogel particles formed in the form of particles, the hydrogel fiber in which the hydrogel is formed in a linear shape has a very large specific surface area, has strong and supple mechanical properties, and has an arrangement with a high aspect ratio. It is expected that various functions will be created because of its features such as controllability and controllability of the diffusion direction of functional substances.

By the way, when an aqueous solution of sodium alginate is added to an aqueous solution of calcium chloride, an ion-crosslinked hydrogel of calcium alginate is formed by ion exchange between calcium ions and sodium ions. Hydrogel fibers can be manufactured by utilizing this property. In Patent Documents 1 and 2, an aqueous calcium chloride solution is allowed to flow between a large-diameter pipe on the outside and a small-diameter pipe on the inside of a double-tube type microreactor, and an aqueous sodium alginate solution is allowed to flow through the small-diameter pipe. A method for producing a hydrogel fiber is disclosed in which they are merged to form an ion-crosslinked hydrogel of calcium alginate by ion exchange between calcium ions and sodium ions.

International release 2011/046105 Japanese Unexamined Patent Publication No. 2007-14936

However, with the techniques disclosed in Patent Documents 1 and 2, it is difficult to arbitrarily control the fiber diameter of the obtained hydrogel fiber.

An object of the present invention is to provide a method capable of producing a hydrogel fiber having a desired fiber diameter.

In the present invention, a first aqueous solution containing metal ions is circulated in a pipe, and a second aqueous solution containing a gel-forming substance that forms an ion-crosslinked hydrogel by ion exchange with the metal ions is provided in the pipe. A method for producing a hydrogel fiber by supplying it into a first aqueous solution and merging it, wherein the concentration of the gel-forming substance in the second aqueous solution is in the range of 0.50% by mass or more and 5.0% by mass or less. At the same time, the flow velocity ratio of the first aqueous solution to the second aqueous solution is set in the range of 0.25 or more and 10 or less, and the flow rate ratio of the first aqueous solution to the second aqueous solution is 0.10 or more and 40 or less. Set in the range.

In the present invention, a first aqueous solution containing metal ions is circulated in a pipe, and a second aqueous solution containing a gel-forming substance that forms an ion-crosslinked hydrogel by ion exchange with the metal ions is provided in the pipe. It is a method of controlling the fiber diameter of a hydrogel fiber produced by supplying it into a first aqueous solution and merging it, and the concentration of the gel-forming substance in the second aqueous solution is 0.50% by mass or more and 5.0% by mass. % Or less, the flow velocity ratio of the first aqueous solution to the second aqueous solution is set in the range of 0.25 or more and 10 or less, and the first aqueous solution has a correlation with the fiber diameter. 2 Set the flow rate ratio to the aqueous solution in the range of 0.10 or more and 40 or less to a value corresponding to the target fiber diameter.

According to the present invention, the concentration of the gel-forming substance in the second aqueous solution is set in the range of 0.50% by mass or more and 5.0% by mass or less, and the flow velocity ratio of the first aqueous solution to the second aqueous solution is 0.25 or more. When set in the range of 10 or less, the fiber diameter of the obtained hydrogel fiber has a correlation with the flow ratio in the range where the flow ratio of the first aqueous solution to the second aqueous solution is 0.10 or more and 40 or less. , The fiber diameter of the hydrogel fiber obtained by the setting can be controlled, and therefore, the flow ratio having a correlation with the fiber diameter is set to a value corresponding to the target fiber diameter in the range of 0.10 or more and 40 or less. When set to, a hydrogel fiber having a desired fiber diameter can be produced. That is, according to the present invention, it is possible to control the fiber diameter by the flow rate ratio in a specific range of the flow velocity ratio.

It is a figure which shows the structure of the hydrogel fiber manufacturing system. It is a vertical sectional view of a main part of a microreactor. It is sectional drawing of IIB-IIB in FIG. 2A. It is a vertical cross-sectional view of the main part of the microreactor of the first modification. FIG. 3A is a sectional view taken along line III-III in FIG. 3A. It is a vertical cross-sectional view of the main part of the microreactor of the second modification. It is a vertical cross-sectional view of the main part of the microreactor of the third modification. It is a cross-sectional view of VB-VB in FIG. 5A. It is a vertical cross-sectional view of the main part of the microreactor of the 4th modification. 6A is a sectional view taken along line VIB-VIB in FIG. 6A. It is a vertical sectional view of the main part of the microreactor of the 5th modification. The flow rate ratio (Q ₁ / Q ₂ ) of the first aqueous solution to the second aqueous solution for Examples 1 to 8 and 11 and Comparative Examples 1 and 12 and 13 and the fiber diameter of the obtained hydrogel fiber. It is a graph which shows the relationship.

Hereinafter, embodiments will be described in detail.

(Hydrogel Fiber Manufacturing System S)
FIG. 1 shows a hydrogel fiber manufacturing system S used in the hydrogel fiber manufacturing method according to the embodiment.

The hydrogel fiber manufacturing system S includes a microreactor 10. FIG. 2 shows the microreactor 10.

The microreactor 10 is a double pipe type having an outer large-diameter pipe 111 and an inner small-diameter pipe 112 provided coaxially, and the tip of the small-diameter pipe 112 is positioned in the middle portion of the large-diameter pipe 111. There is. A first flow path 121 is formed between the large-diameter pipe 111 and the small-diameter pipe 112, a second flow path 122 is formed inside the small-diameter pipe 112, and the downstream side of the tip of the small-diameter pipe 112. A confluence portion 123 of the first and second flow paths is configured. The microreactor 10 has first and second aqueous solution inflow portions 131 and 132 on the upstream side, and communicates with the first and second flow paths 121 and 122, respectively. The microreactor 10 has a discharge unit 14 on the downstream side.

The inner diameter [Phi _in large diameter pipe 111 which constitutes the first flow path 121 is preferably 1.5mm or more, more preferably 2.0mm or more, more preferably 2.5mm or more, preferably 10mm or less, It is more preferably 8.0 mm or less, still more preferably 6.0 mm or less. The inner diameter [Phi _in large diameter pipe 111 is preferably 1.5mm or more 10mm or less, more preferably 2.0mm or more 8.0mm or less, more preferably 2.5mm or more 6.0mm or less.

The outer diameter φ _out of the small diameter pipe 112 constituting the first flow path 121 is preferably 0.50 mm or more, more preferably 1.0 mm or more, further preferably 1.5 mm or more, and preferably 2.2 mm. Below, it is more preferably 2.0 mm or less, still more preferably 1.8 mm or less. The outer diameter φ _out of the small diameter pipe 112 is preferably 0.50 mm or more and 2.2 mm or less, more preferably 1.0 mm or more and 2.0 mm or less, and further preferably 1.5 mm or more and 1.8 mm or less.

The thickness of the first flow path 121 is obtained by halving the difference between the inner diameter Φ _in of the large diameter pipe 111 and the outer diameter Φ _out of the small diameter pipe 112, and is preferably 0.10 mm or more, more preferably 0.10 mm or more. It is 0.20 mm or more, more preferably 0.30 mm or more, preferably 4.8 mm or less, more preferably 3.0 mm or less, still more preferably 2.0 mm or less. The thickness of the first flow path 121 is preferably 0.10 mm or more and 4.8 mm or less, more preferably 0.20 mm or more and 3.0 mm or less, and further preferably 0.30 mm or more and 2.0 mm or less.

Inner diameter phi _in the small diameter pipe 112 constituting a second flow path 122 is preferably 0.010mm or more, more preferably 0.10mm or more, more preferably 0.15mm or more, and preferably 5.0mm or less , More preferably 1.0 mm or less, still more preferably 0.80 mm or less. Inner diameter phi _in the small-diameter pipe 112 is preferably 0.010mm or 5.0mm or less, more preferably 0.10mm or 1.0mm or less, more preferably 0.15mm or 0.80mm or less.

The inner shell of the large-diameter pipe 111 and the outer and inner shells of the small-diameter pipe 112 are preferably circular, but may be non-circular, and in that case, the inner diameter Φ _in of the large-diameter pipe 111 or the small-diameter pipe The outer diameter φ _out and the inner diameter φ _in of 112 mean the diameter equivalent to hydraulic power (= 4 × (cross-sectional area) / (edge length)).

A first aqueous solution supply pipe 221 extending from the first storage tank 211 for storing the first aqueous solution is connected to the first aqueous solution inflow portion 131 of the microreactor 10. Similarly, a second aqueous solution supply pipe 222 extending from the second storage tank 212 for storing the second aqueous solution is connected to the second aqueous solution inflow section 132. In each of the first and second aqueous solution supply pipes 221,222, cocks 231,232 for switching the flow and shutoff of the aqueous solution, pumps 241,242 for sending the aqueous solution, and for detecting the flow rate of the aqueous solution. The flowmeters 251,252 of the above are provided in order from the upstream side, and the pressure gauges 261,262 for detecting the pressure of the aqueous solution are attached to the downstream side of the flowmeters 251,252. The pumps 241,242 and the flowmeters 251,252 are electrically connected to each other, and are configured to perform feedback control of the flow rate of the aqueous solution. A fiber recovery pipe 27 extends from the discharge portion 14 of the microreactor 10 and is connected to the fiber recovery tank 28.

(Manufacturing method of hydrogel fiber)
In the method for producing a hydrogel fiber according to the embodiment, first, a first aqueous solution containing metal ions and a second aqueous solution containing a gel-forming substance that forms an ion-crosslinked hydrogel by ion exchange with the metal ions are prepared. , Are charged into the first and second storage tanks 211 and 212 of the hydrogel fiber manufacturing system S, respectively. Next, the cocks 231 and 232 interposed in the first and second aqueous solution supply pipes 221 and 222 are opened and the pumps 241, 242 are operated, and the first and second aqueous solution supply pipes 221 and 222 are connected to the first and second solutions, respectively. 2 The aqueous solution is circulated and supplied to the microreactor 10. As a result, in the microreactor 10, the first aqueous solution is circulated in the first flow path 121 outside the small diameter pipe 112 in the large diameter pipe 111, and the second aqueous solution is circulated in the second flow path 122 in the small diameter pipe 112. The second aqueous solution is supplied into the first aqueous solution at the merging section 123 to be circulated and merged. That is, the supply of the second aqueous solution into the first aqueous solution is performed from another small-diameter pipe 112 provided in the large-diameter pipe 111. In this case, the second aqueous solution is supplied to the intermediate portion of the first aqueous solution so that the outer circumference of the second aqueous solution is covered with the first aqueous solution. Then, a hydrogel fiber is produced by forming an ion-crosslinked hydrogel by ion exchange between the first aqueous solution and the second aqueous solution, and the hydrogel fiber is recovered in the fiber recovery tank 28 via the fiber recovery tube 27. ..

In the method for producing a hydrogel fiber according to the embodiment, at this time, the concentration c ₂ of the gel-forming substance in the second aqueous solution is set in the range of 0.50% by mass or more and 5.0% by mass or less, and the first aqueous solution is used. The flow velocity ratio (u ₁ / u ₂ ) to the second aqueous solution is set in the range of 0.25 or more and 10 or less, and the flow rate ratio (Q ₁ / Q ₂ ) of the first aqueous solution to the second aqueous solution is 0.10 or more and 40. Set in the following range.

The present inventors set the concentration c ₂ of the gel-forming substance in the second aqueous solution in the range of 0.50% by mass or more and 5.0% by mass or less, and the flow velocity ratio of the first aqueous solution to the second aqueous solution (u _1). When / u ₂ ) is set in the range of 0.25 or more and 10 or less, the fiber diameter of the obtained hydrogel fiber has a flow rate ratio (Q ₁ / Q ₂ ) of the first aqueous solution to the second aqueous solution of 0.10 or more. It was found that there is a correlation with the flow rate ratio (Q ₁ / Q ₂ ) in the range of 40 or less. It is speculated that this may be related to the fact that the gelation of the second aqueous solution occurs after the steady state in which the flow rates of the first and second aqueous solutions are equalized. From this, according to the method for manufacturing a hydrogel fiber according to the embodiment, the fiber diameter of the hydrogel fiber obtained by setting the flow rate ratio (Q ₁ / Q ₂ ) can be controlled, and therefore, the fiber diameter and If the flow rate ratio (Q ₁ / Q ₂ ) having the correlation with the above is set to a value corresponding to the target fiber diameter in the range of 0.1 or more and 40 or less, a hydrogel fiber having a desired fiber diameter can be manufactured. Can be done. That is, according to the method for manufacturing a hydrogel fiber according to the embodiment, it is possible to control the fiber diameter by the flow rate ratio in the flow velocity ratio in a specific range.

Here, examples of the metal ion contained in the first aqueous solution include potassium ion as a monovalent metal ion, and calcium ion, magnesium ion, iron ion (II), and copper as a polyvalent metal ion. Divalent metal ions such as ion (II), zinc ion and manganese ion; trivalent metal ion such as aluminum ion and iron ion (III) can be mentioned. From the viewpoint of the hydrogel formation mechanism, the first aqueous solution preferably contains one or more of these metal ions. From the viewpoint of reactivity, potassium ion is preferable as the monovalent metal ion, and from the viewpoint of reactivity, calcium ion and magnesium ion are preferable as the polyvalent metal ion.

The first aqueous solution is preferably an aqueous solution containing a metal salt containing metal ions from the viewpoint of improving the reaction rate. Metal salts containing metal ions include inorganic acid salts such as chloride salts, sulfates, nitrates, carbonates and phosphates; monovalent metal salts of organic acid salts such as lactates, citrates and acetates. And polyvalent metal salts. From the viewpoint of the hydrogel formation mechanism, the first aqueous solution preferably contains one or more of these metal salts. From the viewpoint of reactivity, a chloride salt is preferable as the inorganic acid salt.

The concentration c ₁ of the metal salt in the first aqueous solution is preferably 0.30% by mass or more, more preferably 0.50% by mass or more, still more preferably 1.0% by mass or more, from the viewpoint of accurately controlling the fiber diameter. From the same viewpoint, it is preferably 30% by mass or less, more preferably 20% by mass or less, and further preferably 10% by mass or less. The concentration c ₁ of this metal salt is preferably 0.30% by mass or more and 30% by mass or less, more preferably 0.50% by mass or more and 20% by mass or less, and further preferably 1.0% by mass or more and 10% by mass or less. is there.

The first aqueous solution may contain a surfactant, an organic solvent, a preservative and the like as long as the action and effect of controlling the fiber diameter are not impaired.

The viscosity η ₁ of the first aqueous solution may be prepared by appropriately adding a viscosity modifier or the like, if necessary. The viscosity η ₁ of the first aqueous solution is preferably 0.10 mPa · s or more, more preferably 0.50 mPa · s or more, still more preferably 1.0 mPa · s or more, from the viewpoint of accurately controlling the fiber diameter. From the same viewpoint, it is preferably 10000 mPa · s or less, more preferably 5000 mPa · s or less, and further preferably 3000 mPa · s or less. The viscosity η ₁ of the first aqueous solution is preferably 0.10 mPa · s or more and 10000 mPa · s or less, more preferably 0.50 mPa · s or more and 5000 mPa · s or less, and further preferably 1.0 mPa · s or more and 3000 mPa · s or less. Is. Here, the viscosity eta ₂ of the second aqueous solution viscosity eta ₁ and below the first aqueous solution is measured by the viscosity measuring instrument such as a B-type viscometer.

The first aqueous solution is preferably circulated through the first flow path 121 under laminar flow conditions. The Reynolds number Re ₁ is preferably 0.10 or more, more preferably 0.30 or more, still more preferably 0.50 or more from the viewpoint of accurately controlling the fiber diameter, and is preferably from the same viewpoint. Is 1500 or less, more preferably 1200 or less, still more preferably 1000 or less. The Reynolds number Re ₁ of the first aqueous solution is preferably 0.10 or more and 1500 or less, more preferably 0.30 or more and 1200 or less, and further preferably 0.50 or more and 1000 or less.

The flow velocity u ₁ of the first aqueous solution to be passed through the first flow path 121 is preferably 0.050 m / sec or more, more preferably 0.10 m / sec or more, still more preferably 0, from the viewpoint of accurately controlling the fiber diameter. It is .15 m / sec or more, and from the same viewpoint, it is preferably 10 m / sec or less, more preferably 5.0 m / sec or less, still more preferably 3.0 m / sec or less. The flow velocity u ₁ of the first aqueous solution is preferably 0.050 m / sec or more and 10 m / sec or less, more preferably 0.10 m / sec or more and 5.0 m / sec or less, and further preferably 0.15 m / sec or more. It is 0 m / sec or less.

Flow rate to _{Q 1} first aqueous solution to be passed through the first flow path 121, from the viewpoint of controlling precisely the fiber diameter, preferably 5.0 ml / min or more, more preferably 10 ml / min or more, more preferably 20 ml / It is more than a minute, and from the same viewpoint, it is preferably 2000 ml / min or less, more preferably 1000 ml / min or less, still more preferably 500 ml / min or less. Flow rate to _{Q 1} the first aqueous solution is preferably 5.0 ml / min to 2000 ml / min or less, more preferably 10 ml / min or more 1000ml / min or less, even more preferably not more than 20 ml / min or more 500 ml / min.

Examples of the gel-forming substance contained in the second aqueous solution include alginates such as sodium alginate, potassium alginate, and ammonium alginate; κ-carrageenan, ι-carrageenan, and LM pectin. From the viewpoint of the hydrogel forming mechanism, the second aqueous solution preferably contains one or more of these gel-forming substances. As the gel-forming substance contained in the second aqueous solution, sodium alginate and κ-carrageenan are preferable from the viewpoint of reactivity and the strength of the obtained hydrogel fiber. Alginate is formed by calcium ions and the like, κ-carrageenan is formed by potassium ions, ι-carrageenan is formed by calcium ions, and LM pectin is formed by calcium ions and the like.

The concentration c ₂ of the gel-forming substance in the second aqueous solution is 0.5% by mass or more and 5.0% by mass or less, but from the viewpoint of accurately controlling the fiber diameter, it is preferably 1.0% by mass or more, more preferably 1.0% by mass or more. It is 2.0% by mass or more, more preferably 3.0% by mass or more. In particular, when the concentration c ₂ of the gel-forming substance in the second aqueous solution is 3.0% by mass or more and 5.0% by mass or less, the fiber diameter of the hydrogel fiber is the first aqueous solution and the second aqueous solution flowing in the pipe. It has been found that it can be approximated with high accuracy by the following relational expression calculated based on the flow rate ratio (Q ₁ / Q ₂ ) of. Therefore, the fiber diameter of the hydrogel fiber can be controlled based on this relational expression.

On the other hand, the concentration c ₂ of the gel-forming substance in the second aqueous solution is preferably 2.0% by mass or less, more preferably 1.0% by mass or less, from the viewpoint of producing a hydrogel fiber having a small fiber diameter.

The second aqueous solution may contain an aqueous and / or oily functional substance, a surfactant, an organic solvent, a reactive substance and the like as long as the action and effect of controlling the fiber diameter are not impaired.

Viscosity eta ₂ of the second aqueous solution may be adjusted concentration c ₂ in the gel-forming _material, molecular weight, and by the operating temperature. The viscosity η ₂ of the second aqueous solution is preferably 10 mPa · s or more, more preferably 50 mPa · s or more, still more preferably 100 mPa · s or more, from the viewpoint of accurately controlling the fiber diameter, and from the same viewpoint. It is preferably 100,000 mPa · s or less, more preferably 50,000 mPa · s or less, and further preferably 30,000 mPa · s or less. The viscosity η ₂ of this second aqueous solution is preferably 10 mPa · s or more and 100,000 mPa · s or less, more preferably 50 mPa · s or more and 50,000 mPa · s or less, and further preferably 100 mPa · s or more and 30,000 mPa · s or less.

The second aqueous solution is preferably circulated through the second flow path 122 under laminar flow conditions. The Reynolds number Re ₂ is preferably 0.0010 or more, more preferably 0.010 or more, still more preferably 0.10 or more from the viewpoint of accurately controlling the fiber diameter, and is preferably 0.10 or more from the same viewpoint. Is 1000 or less, more preferably 500 or less, still more preferably 300 or less. The Reynolds number Re ₂ of this second aqueous solution is preferably 0.0010 or more and 1000 or less, more preferably 0.010 or more and 500 or less, and further preferably 0.10 or more and 300 or less.

The flow velocity u ₂ of the second aqueous solution flowing through the second flow path 122 is preferably 0.050 m / sec or more, more preferably 0.10 m / sec or more, still more preferably 0, from the viewpoint of accurately controlling the fiber diameter. It is .15 m / sec or more, and from the same viewpoint, it is preferably 10 m / sec or less, more preferably 5.0 m / sec or less, still more preferably 3.0 m / sec or less. The flow velocity u ₂ of the second aqueous solution is preferably 0.050 m / sec or more and 10 m / sec or less, more preferably 0.10 m / sec or more and 5.0 m / sec or less, and further preferably 0.15 m / sec or more. It is 0 m / sec or less.

Flow rate _{Q 2} of the second aqueous solution to be circulated to the second flow path 122, from the viewpoint of controlling precisely the fiber diameter, preferably 0.10 ml / min or more, more preferably 0.50 ml / min or more, more preferably 1 It is 0.0 ml / min or more, and from the same viewpoint, it is preferably 500 ml / min or less, more preferably 300 ml / min or less, still more preferably 100 ml / min or less. Flow rate _{Q 2} of the second aqueous solution is preferably 0.10 ml / min to 500 ml / min or less, more preferably 0.50 ml / min or more 300 ml / min or less, more preferably 1.0 ml / min to 100ml / min or less Is.

Regarding the relationship between the first and second aqueous solutions, the flow velocity u ₁ of the first aqueous solution may be the same as the flow velocity u _{2 of} the second aqueous solution, or may be faster than the flow velocity u ₂ of the second aqueous solution. Alternatively, it may be slower than the flow velocity u ₂ of the second aqueous solution. The flow velocity ratio (u ₁ / u ₂ ) of the first aqueous solution to the second aqueous solution is 0.25 or more and 10 or less. From the viewpoint of controlling the fiber diameter with high accuracy, it is preferably 0.30 or more, more preferably 0.50 or more, still more preferably 1.0 or more, and from the same viewpoint, preferably 8.0 or less, more. It is preferably 6.0 or less, more preferably 5.0 or less. This flow velocity ratio (u ₁ / u ₂ ) is preferably 0.30 or more and 8.0 or less, more preferably 0.50 or more and 6.0 or less, and further preferably 1.0 or more and 5.0 or less.

The flow rate Q ₁ of the first aqueous solution may be the same as the flow rate Q _{2 of} the second aqueous solution, may be larger than the flow rate Q _{2 of} the second aqueous solution, or may be higher than the flow rate Q _{2 of} the second aqueous solution. May be less. The flow rate ratio (Q ₁ / Q ₂ ) of the first aqueous solution to the second aqueous solution is 0.10 or more and 40 or less, but if the flow rate ratio (Q ₁ / Q ₂ ) suitable for the target fiber diameter is appropriately set, Good. From the viewpoint of accurately controlling the fiber diameter and producing a hydrogel fiber having a small fiber diameter, it is preferably 0.50 or more, more preferably 1.0 or more, still more preferably 3.0 or more, and accurate. From the viewpoint of controlling the fiber diameter well, it is preferably 35 or less, more preferably 30 or less, still more preferably 25 or less. This flow rate ratio (Q ₁ / Q ₂ ) is preferably 0.50 or more and 35 or less, more preferably 1.0 or more and 30 or less, and further preferably 3.0 or more and 25 or less.

Further, the Reynolds number Re ₁ of the first aqueous solution is preferably larger than the Reynolds number Re ₂ of the second aqueous solution. The ratio of the Reynolds number Re ₁ of the first aqueous solution to the Reynolds number Re ₂ of the second aqueous solution (Re ₁ / Re ₂ ) is preferably 1.0 or more, more preferably 5.0 or more, still more preferably 10 or more. From the same viewpoint, it is preferably 100,000 or less, more preferably 70,000 or less, and further preferably 50,000 or less. The ratio of Reynolds numbers (Re ₁ / Re ₂ ) is preferably 1.0 or more and 100,000 or less, more preferably 5.0 or more and 70,000 or less, and further preferably 10 or more and 50,000 or less.

The concentration c ₁ of the metal salt in the first aqueous solution may be the same as the concentration c ₂ of the gel-forming substance in the second aqueous solution, or may be lower than the concentration c ₂ of the gel-forming substance in the second aqueous solution. Alternatively, it may be higher than the concentration c ₂ of the gel-forming substance in the second aqueous solution. The ratio to the concentration _{c 2} in the gel-forming material in a second aqueous solution having a concentration _{c 1} of the metal salt in the first aqueous solution _(c 1 / _{c 2),} from the viewpoint of controlling precisely the fiber diameter, preferably 0.050 or more, It is more preferably 0.10 or more, still more preferably 0.30 or more, and from the same viewpoint, it is preferably 60 or less, more preferably 40 or less, still more preferably 20 or less. This concentration ratio (c ₁ / c ₂ ) is preferably 0.050 or more and 60 or less, more preferably 0.10 or more and 40 or less, and further preferably 0.30 or more and 20 or less.

The viscosity η ₁ of the first aqueous solution is preferably lower than the viscosity η ₂ of the second aqueous solution. The ratio viscosity eta ₁ of the first aqueous solution viscosity eta ₂ of the second aqueous solution (η _{2 /} η _1), from the viewpoint of controlling precisely the fiber diameter, preferably 1.0 or more, more preferably 5.0 or more It is more preferably 10 or more, and from the same viewpoint, it is preferably 100,000 or less, more preferably 50,000 or less, still more preferably 30,000 or less. This viscosity ratio (η ₂ / η ₁ ) is preferably 1.0 or more and 100,000 or less, more preferably 5.0 or more and 50,000 or less, and further preferably 10 or more and 30,000 or less.

The temperature of the first aqueous solution is preferably the same as the temperature of the second aqueous solution, but may be different.

The hydrogel fiber formed in the microreactor 10 is recovered in the fiber recovery tank 28 via the fiber recovery pipe 27. The fiber diameter of the hydrogel fiber is preferably 10 μm or more, more preferably 50 μm or more, still more preferably 70 μm or more, and preferably 1000 μm or less, more preferably 800 μm or less, still more preferably 700 μm or less. The fiber diameter of the hydrogel fiber is preferably 10 μm or more and 1000 μm or less, more preferably 50 μm or more and 800 μm or less, and further preferably 70 μm or more and 700 μm or less. The fiber diameter of the hydrogel fiber can be measured from an image observed with an optical microscope. Further, the "fiber diameter" in the present application is the fiber diameter in a wet state in an aqueous solution.

Fiber diameter of the hydrogel fiber is preferably smaller than the inner diameter phi _in the small diameter pipe 112. Fiber diameter of the hydrogel fiber, with respect to the inner diameter phi _in the small-diameter pipe 112, preferably 0.10 times or more, more preferably 0.15 times or more, more preferably 0.20 times or more, preferably Is 0.95 times or less, more preferably 0.90 times or less, still more preferably 0.85 times or less. Fiber diameter of the hydrogel fiber, with respect to the inner diameter phi _in the small-diameter pipe 112, preferably 0.95 to 0.10 times or less, 0.90 or less and more preferably 0.15 times or more, more preferably 0 .20 times or more and 0.85 times or less.

The recovered hydrogel fiber is used as a compounding material for, for example, cosmetics, pharmaceuticals, quasi-drugs, foods and the like.

(Other embodiments)
In the above embodiment, a double-tube type microreactor 10 in which the small-diameter pipe 112 is provided in the large-diameter pipe 111 is used, but the present invention is not particularly limited to this, and is shown in FIGS. 3A and 3B. As described above, the first pipe 15 and the second pipe 16 which is introduced into the first pipe from the side and is provided so as to bend at the center thereof and extend along the first pipe to open. The microreactor 10 provided may be used, and the second aqueous solution may be supplied to the intermediate portion of the first aqueous solution so that the outer periphery of the second aqueous solution is covered with the first aqueous solution.

In the above embodiment, the microreactor 10 is provided in which the small-diameter pipe 112 is provided in the large-diameter pipe 111 and the tip of the small-diameter pipe 112 is positioned in the middle portion of the large-diameter pipe 111. Therefore, the outer periphery of the second aqueous solution is the second. The configuration is such that the second aqueous solution is supplied to the intermediate portion of the first aqueous solution so as to be covered with the first aqueous solution, but the present invention is not particularly limited to this, and as shown in FIG. 4, the first pipe 15 and from there. Using the microreactor 10 provided with the branched second pipe 16, the first and second aqueous solutions are circulated in the first and second pipes 15 and 16, respectively, and the first aqueous solution is introduced through the opening of the second pipe 16. The second aqueous solution is supplied, and the second aqueous solution is sandwiched between the first aqueous solution and the inner wall on the opening side of the second pipe 16 in the first pipe 15, and flows along the inner wall of the first pipe 15. You may.

Further, as shown in FIGS. 5A and 5B, the first pipe 15 and the first pipe 15 are introduced from the side and are provided so as to extend and open along the inner wall of the introduced side. Using a microreactor 10 provided with two pipes 16, the first and second aqueous solutions are circulated in the first and second pipes 15 and 16, respectively, and the second aqueous solution is circulated into the first aqueous solution through the opening of the second pipe 16. Is supplied, and the second aqueous solution is sandwiched between the first aqueous solution and the inner wall of the first pipe 15 on the arrangement side of the second pipe 16 and circulates along the inner wall of the first pipe 15. Good.

Further, as shown in FIGS. 6A and 6B, the first pipe 15 and the first pipe are introduced from the side and are provided so as to extend to the vicinity of the inner wall facing the introduced side and open. Using the microreactor 10 provided with the second pipe 16, the first and second aqueous solutions were circulated in the first and second pipes 15 and 16, respectively, and the first aqueous solution was introduced through the opening of the second pipe 16. The two aqueous solutions are supplied, and the second aqueous solution is sandwiched between the first aqueous solution and the inner wall of the first pipe 15 on the side opposite to the introduction side of the second pipe 16, and flows along the inner wall of the first pipe 15. It may be a configuration.

In the above embodiment, the microreactor 10 in which one small diameter pipe 112 is provided in the large diameter pipe 111 is shown, but the present invention is not particularly limited to this, and as shown in FIG. 7, the large diameter pipe 111 is shown. The microreactor 10 may be provided with a plurality of small-diameter pipes 112 inside. In this case, the flow rate of the second aqueous solution is the total amount of the second aqueous solution flowing through the plurality of small diameter pipes 112.

(Manufacturing of hydrogel fiber)
Hydrogel fibers were prepared as in Examples 1 to 11 and Comparative Examples 1 and 2 below, using an aqueous solution of calcium chloride as a first aqueous solution and an aqueous solution of sodium alginate as a second aqueous solution. Further, hydrogel fibers were prepared as shown in Examples 12 and 13 below, using the potassium chloride aqueous solution as the first aqueous solution and the κ-carrageenan aqueous solution as the second aqueous solution. The contents of each are also shown in Tables 1 and 2.

<Example 1>
693 g of ion-exchanged water is charged in a 1 L glass beaker, 7 g of calcium chloride (manufactured by Wako Pure Chemical Industries, Ltd.) is added thereto and dissolved at room temperature to prepare a calcium chloride aqueous solution having a concentration c ₁ of 1.0% by mass. It was prepared as a first aqueous solution (viscosity η ₁ : 1.0 mPa · s, specific gravity: 1.013). In addition, 693 g of ion-exchanged water was charged into another 1 L glass beaker, and 7 g of sodium alginate (manufactured by Wako Pure Chemical Industries, Ltd.) was added thereto and heated to 70 ° C. to dissolve the concentration c ₂ . A 0% by mass sodium alginate aqueous solution was prepared as a second aqueous solution (viscosity η ₂ : 290 mPa · s, specific gravity: 1.004).

Using the hydrogel fiber manufacturing system S having the same configuration as shown in FIG. 1, the first aqueous solution was charged into the first storage tank 211 and the second aqueous solution was charged into the second storage tank 212, respectively. Then, when the first and second aqueous solutions whose temperature has been adjusted to 25 ° C. are flowed into the first and second flow paths 121 and 122, respectively, and merged at the merging portion 123, the positions where the first and second aqueous solutions come into contact with each other. Immediately after that, the second aqueous solution gelled to form a hydrogel fiber, which was recovered in a fiber recovery tank 28 composed of a 3 L beaker containing ion-exchanged water. The outer diameter Φ _out of the large diameter pipe 111 of the microreactor 10 was 3.2 mm, and the inner diameter Φ _in was 2.5 mm. The outer diameter φ _out of the small diameter pipe 112 was 1.6 mm and φ _in was 0.75 mm. A gear pump (model: DGS.11EEV2NN15000 Tuthill) was used for the pumps 241,242.

In Example 1, the first aqueous solution, the flow rate _{Q 1} of 49 ml / min with laminar flow (Reynolds number _Re 1: 260) with circulating in the second aqueous solution, laminar flow in which the flow rate _{Q 2} and 26 ml / min It was distributed at (Reynolds number Re ₂ : 2.5). Therefore, the flow rate ratio (Q ₁ / Q ₂ ) of the first aqueous solution to the second aqueous solution is 1.9. Since the flow velocity u ₁ of the first aqueous solution was 280 mm / sec and the flow velocity u ₂ of the second aqueous solution was 980 mm / sec, the flow velocity ratio (u ₁ / u ₂ ) of the first aqueous solution to the second aqueous solution was 0.29. is there.

When the obtained hydrogel fiber was observed with an optical microscope, the fiber diameter in the wet state was 520 μm.

<Example 2>
In Example 2, the flow rate _{Q 2} of the second aqueous solution 5.0 ml / min (Reynolds number _Re 2: 0.49) except for using, was subjected to the same procedure as in Example 1. Therefore, the flow rate ratio (Q ₁ / Q ₂ ) of the first aqueous solution to the second aqueous solution is 9.8. Further, since the flow velocity u ₂ of the second aqueous solution was 190 mm / sec, the flow velocity ratio (u ₁ / u ₂ ) of the first aqueous solution to the second aqueous solution was 1.5.

When the obtained hydrogel fiber was observed with an optical microscope, the fiber diameter in the wet state was 250 μm.

<Example 3>
In Example 3, the flow rate to _{Q 1} first aqueous solution 150ml / min (Reynolds number _Re 1: 780) and then, also, the flow rate _{Q 2} of the second aqueous solution 5.0 ml / min (Reynolds number _Re 2: 0.49 ), The same operation as in Example 1 was performed. Therefore, the flow rate ratio (Q ₁ / Q ₂ ) of the first aqueous solution to the second aqueous solution is 30. Further, since the flow velocity u ₁ of the first aqueous solution was 860 mm / sec and the flow velocity u ₂ of the second aqueous solution was 190 mm / sec, the flow velocity ratio (u ₁ / u ₂ ) of the first aqueous solution to the second aqueous solution was 4. It is 5.

When the obtained hydrogel fiber was observed with an optical microscope, the fiber diameter in the wet state was 150 μm.

<Example 4>
In Example 4, the flow rate to _{Q 1} first aqueous solution 200ml / min (Reynolds number _Re 1: 1100) and then, also, the flow rate _{Q 2} of the second aqueous solution 5.0 ml / min (Reynolds number _Re 2: 0.49 ), The same operation as in Example 1 was performed. Therefore, the flow rate ratio (Q ₁ / Q ₂ ) of the first aqueous solution to the second aqueous solution is 40. Further, since the flow velocity u ₁ of the first aqueous solution was 1200 mm / sec and the flow velocity u ₂ of the second aqueous solution was 190 mm / sec, the flow velocity ratio (u ₁ / u ₂ ) of the first aqueous solution to the second aqueous solution was 6. It is 3.

When the obtained hydrogel fiber was observed with an optical microscope, the fiber diameter in the wet state was 80 μm.

<Example 5>
In the microreactor 10 used for producing the hydrogel fiber in Example 5, the outer diameter Φ _out of the large-diameter pipe 111 was 3.2 mm and the inner diameter Φ _in was 2.5 mm. The outer diameter φ _out of the small diameter pipe 112 was 1.6 mm, and the inner diameter φ _in was 0.50 mm.

Then, the flow rate _{Q 2} of the second aqueous solution 12 ml / min (Reynolds number _Re 2: 1.7) except for using, was subjected to the same procedure as in Example 1. Therefore, the flow rate ratio (Q ₁ / Q ₂ ) of the first aqueous solution to the second aqueous solution is 4.1. Further, since the flow velocity u ₂ of the second aqueous solution was 1000 mm / sec, the flow velocity ratio (u ₁ / u ₂ ) of the first aqueous solution to the second aqueous solution was 0.28.

When the obtained hydrogel fiber was observed with an optical microscope, the fiber diameter in the wet state was 300 μm.

<Example 6>
In Example 6, the flow rate to _{Q 1} first aqueous solution 99 ml / min (Reynolds number _Re 1: 520) except for using, was subjected to the same procedure as in Example 5. Therefore, the flow rate ratio (Q ₁ / Q ₂ ) of the first aqueous solution to the second aqueous solution is 8.3. Further, since the flow velocity u ₁ of the first aqueous solution was 570 mm / sec, the flow velocity ratio (u ₁ / u ₂ ) of the first aqueous solution to the second aqueous solution was 0.57.

When the obtained hydrogel fiber was observed with an optical microscope, the fiber diameter in the wet state was 200 μm.

<Example 7>
In the microreactor 10 used for producing the hydrogel fiber in Example 7, the outer diameter Φ _out of the large-diameter pipe 111 was 3.2 mm and the inner diameter Φ _in was 2.5 mm. The outer diameter φ _out of the small diameter pipe 112 was 1.6 mm, and the inner diameter φ _in was 0.25 mm. Further, the flow rate _{Q 2} of the second aqueous solution 2.9 ml / min (Reynolds number _Re 2: 0.84) except for using, was subjected to the same procedure as in Example 1. Therefore, the flow rate ratio (Q ₁ / Q ₂ ) of the first aqueous solution to the second aqueous solution is 17. Further, since the flow velocity u ₂ of the second aqueous solution was 980 mm / sec, the flow velocity ratio (u ₁ / u ₂ ) of the first aqueous solution to the second aqueous solution was 0.29.

When the obtained hydrogel fiber was observed with an optical microscope, the fiber diameter in the wet state was 150 μm.

<Example 8>
In Example 8, the flow rate to _{Q 1} first aqueous solution 99 ml / min (Reynolds number _Re 1: 520) except for using, was subjected to the same procedure as in Example 7. Therefore, the flow rate ratio (Q ₁ / Q ₂ ) of the first aqueous solution to the second aqueous solution is 34. Further, since the flow velocity u ₁ of the first aqueous solution was 570 mm / sec, the flow velocity ratio (u ₁ / u ₂ ) of the first aqueous solution to the second aqueous solution was 0.58.

When the obtained hydrogel fiber was observed with an optical microscope, the fiber diameter in the wet state was 80 μm.

<Example 9>
Embodiment Example 9, 686 g were charged into a glass beaker of deionized water 1L, there concentration c ₂ in which sodium alginate (manufactured by Wako Pure Chemical Industries, Ltd.) was adjusted to a temperature of 25 ° C. and dissolved by 14g introduced 2 A 0.0 mass% sodium alginate aqueous solution (viscosity η ₂ : 2600 mPa · s, specific gravity: 1.008) was used as the second aqueous solution. Further, the flow rate _{Q 2} of the second aqueous solution 5.0 ml / min (Reynolds number _Re 2: 0.059) and with other than the can was subjected to the same procedure as in Example 1. Therefore, the flow rate ratio (Q ₁ / Q ₂ ) of the first aqueous solution to the second aqueous solution is 9.8. Further, since the flow velocity u ₂ of the second aqueous solution was 190 mm / sec, the flow velocity ratio (u ₁ / u ₂ ) of the first aqueous solution to the second aqueous solution was 1.5.

When the obtained hydrogel fiber was observed with an optical microscope, the fiber diameter in the wet state was 450 μm.

<Example 10>
In Example 10, 679 g of ion-exchanged water was charged into a 1 L glass beaker, and 21 g of sodium alginate (manufactured by Wako Pure Chemical Industries, Ltd.) was added thereto to dissolve the mixture, and the concentration c ₂ was adjusted to 25 ° C. A 0.0 mass% sodium alginate aqueous solution (viscosity η ₂ : 11000 mPa · s, specific gravity: 1.016) was used as the second aqueous solution. Further, the flow rate _{Q 2} of the second aqueous solution 4.9 ml / min (Reynolds number _Re 2: 0.013) except for using, was subjected to the same procedure as in Example 9. Therefore, the flow rate ratio (Q ₁ / Q ₂ ) of the first aqueous solution to the second aqueous solution is 10. Further, since the flow velocity u ₂ of the second aqueous solution was 180 mm / sec, the flow velocity ratio (u ₁ / u ₂ ) of the first aqueous solution to the second aqueous solution was 1.6.

When the obtained hydrogel fiber was observed with an optical microscope, the fiber diameter in the wet state was 650 μm.

<Example 11>
In Example 11, 696.5 g of ion-exchanged water was charged into a 1 L glass beaker, and 3.5 g of calcium chloride (manufactured by Wako Pure Chemical Industries, Ltd.) was added thereto to dissolve the mixture, and the concentration was adjusted to 25 ° C. An aqueous solution of calcium chloride having 0.5% by mass of c ₁ (viscosity η ₁ : 1.0 mPa · s, specific gravity: 1.002) was used as the first aqueous solution. Further, the flow rate to _{Q 1} first aqueous solution 100ml / min (Reynolds number _Re 1: 520) and then, the flow rate _{Q 2} of the second aqueous solution 5.0 ml / min (Reynolds number _Re 2: 0.48) except for using , The same operation as in Example 1 was performed. Therefore, the flow rate ratio (Q ₁ / Q ₂ ) of the first aqueous solution to the second aqueous solution is 20. Further, since the flow velocity u ₁ of the first aqueous solution was 580 mm / sec and the flow velocity u ₂ of the second aqueous solution was 190 mm / sec, the flow velocity ratio (u ₁ / u ₂ ) of the first aqueous solution to the second aqueous solution was 3. It is 1.

When the obtained hydrogel fiber was observed with an optical microscope, the fiber diameter in the wet state was 150 μm.

<Comparative example 1>
In the microreactor 10 used for producing the hydrogel fiber in Comparative Example 1, the outer diameter Φ _out of the large-diameter pipe 111 was 3.2 mm and the inner diameter Φ _in was 2.5 mm. The same operation as in Example 3 was performed except that the outer diameter φ _out of the small diameter pipe 112 was 1.6 mm and the inner diameter φ _in was 0.17 mm. The Reynolds number Re ₂ of the second aqueous solution is 2.2. Since the flow velocity u ₂ of the second aqueous solution was 3700 mm / sec, the flow velocity ratio (u ₁ / u ₂ ) of the first aqueous solution to the second aqueous solution was 0.23.

When the obtained hydrogel fiber was observed with an optical microscope, the fiber diameter in the wet state was 50 μm.

<Comparative example 2>
In Comparative Example 2, 699.3 g of ion-exchanged water was charged into a 1 L glass beaker, and 0.7 g of sodium alginate (manufactured by Wako Pure Chemical Industries, Ltd.) was added thereto to dissolve the mixture, and the concentration was adjusted to 25 ° C. The same operation as in Example 2 was carried out except that an aqueous solution of sodium alginate containing 0.10% by mass of c ₂ (viscosity η ₂ : 14 mPa · s, specific gravity: 1.000) was used as the second aqueous solution. The Reynolds number Re ₂ of the second aqueous solution is 10.

As a result, gelation did not proceed in the fiber recovery tube 27, and a hydrogel fiber could not be obtained.

<Example 12>
In Example 12, 630.0 g of ion-exchanged water was charged into a 1 L glass beaker, and 70.0 g of potassium chloride (manufactured by Wako Pure Chemical Industries, Ltd.) was added thereto to dissolve the mixture, and the concentration was adjusted to 25 ° C. An aqueous solution of potassium chloride containing 10% by mass of c ₁ (viscosity η ₁ : 1.0 mPa · s, specific gravity: 1.063) was used as the first aqueous solution. In addition, 693 g of ion-exchanged water was charged into a 1 L glass beaker, and 7 g of κ-carrageenan (manufactured by Tokyo Kasei Kogyo Co., Ltd.) was added to dissolve the mixture and the temperature was adjusted to 25 ° C. The concentration c ₂ was 1.0% by mass. An aqueous solution of κ-carrageenan (viscosity η ₂ : 4100 mPa · s, specific gravity: 1.065) was used as the second aqueous solution.

In the microreactor 10 used for producing the hydrogel fiber, the outer diameter Φ _out of the large diameter pipe 111 was 3.2 mm and the inner diameter Φ _in was 2.5 mm. The outer diameter φ _out of the small diameter pipe 112 was 1.6 mm and φ _in was 0.50 mm.

Then, the flow rate to _{Q 1} first aqueous solution 75ml / min (Reynolds number _Re 1: 410) and then, the flow rate _{Q 2} of the second aqueous solution 9.4 ml / min (Reynolds number _Re 2: 0.10) except for using , The same operation as in Example 1 was performed. Therefore, the flow rate ratio (Q ₁ / Q ₂ ) of the first aqueous solution to the second aqueous solution is 8.0. Further, since the flow velocity u ₁ of the first aqueous solution was 410 mm / sec and the flow velocity u ₂ of the second aqueous solution was 800 mm / sec, the flow velocity ratio (u ₁ / u ₂ ) of the first aqueous solution to the second aqueous solution was 0. 54.

When the obtained hydrogel fiber was observed with an optical microscope, the fiber diameter in the wet state was 470 μm.

<Example 13>
In Example 13, the flow rate to _{Q 1} first aqueous solution 110 ml / min (Reynolds number _Re 1: 600) and then, also, the flow rate _{Q 2} of the second aqueous solution 4.7 ml / min (Reynolds number _Re 2: 0.052 ), The same operation as in Example 12 was performed. Therefore, the flow rate ratio (Q ₁ / Q ₂ ) of the first aqueous solution to the second aqueous solution is 23. Further, since the flow velocity u ₁ of the first aqueous solution was 630 mm / sec and the flow velocity u ₂ of the second aqueous solution was 400 mm / sec, the flow velocity ratio (u ₁ / u ₂ ) of the first aqueous solution to the second aqueous solution was 1. It is 6.

When the obtained hydrogel fiber was observed with an optical microscope, the fiber diameter in the wet state was 190 μm.

(Results and discussion)
In FIG. 7, Examples 1 to 8 and 11 in which the concentration c _{2 of} sodium alginate in the second aqueous solution is 1.0% by mass, and Comparative Example 1 and the concentration c ₂ of κ-carrageenan in the second aqueous solution are 1. The relationship between the flow rate ratio (Q ₁ / Q ₂ ) of the first aqueous solution to the second aqueous solution for Examples 12 and 13 of 0% by mass and the fiber diameter of the obtained hydrogel fiber is shown.

According to FIG. 7, from the results of Examples 1 to 8 and 11, the configuration of the microreactor 10 used when producing the hydrogel fiber, the concentration c ₁ of the first aqueous solution, and the flow rates of the first and second aqueous solutions, respectively. Regardless of Q ₁ , Q ₂ and the flow velocities u ₁ , u _2, etc., the fiber diameter of the obtained hydrogel fiber has a correlation with the flow rate ratio (Q ₁ / Q ₂ ) of the first aqueous solution to the second aqueous solution. I understand. However, in Comparative Example 1 in which the flow velocity ratio (u ₁ / u ₂ ) of the first aqueous solution to the second aqueous solution is as small as 0.20, it can be seen that this correlation is deviated. Further, the same tendency is observed in Examples 12 and 13 in which the concentration c ₂ of κ-carrageenan in the second aqueous solution is 1.0% by mass.

Comparing Examples 9 and 10 in which the concentration c _{2 of} sodium alginate in the second aqueous solution is different, it can be seen that the fiber diameter of the obtained hydrogel fiber becomes smaller as the concentration c _{2 of} sodium alginate in the second aqueous solution becomes lower. .. Further, in Comparative Example 2 in which the concentration c _{2 of} sodium alginate in the second aqueous solution was 0.10% by mass, which was further lower than 1.0% by mass in Example 2, no hydrogel fiber was formed.

The present invention is useful in the technical field of a method for manufacturing a hydrogel fiber and a method for controlling the fiber diameter thereof.

S Hydrogel fiber manufacturing system 10 Microreactor 111 Large-diameter piping 112 Small-diameter piping 121 First flow path 122 Second flow path 123 Confluence section 131 First aqueous solution inflow section 132 Second aqueous solution inflow section 14 Discharge section 15 First piping 16 First 2 Piping 211 1st storage tank 212 2nd storage tank 221 1st aqueous solution supply pipe 222 2nd aqueous solution supply pipe 231,232 Cock 241,242 Pump 251,252 Flow meter 261,262 Pressure gauge 27 Fiber recovery pipe 28 Fiber recovery tank

Claims (9)

A first aqueous solution containing metal ions is circulated in the pipe, and a second aqueous solution containing a gel-forming substance that forms an ion-bridged hydrogel by ion exchange with the metal ions is maintained in the flow direction in the pipe. while after confluence was fed into the first aqueous solution to flow, the one obtained by merging the first and second aqueous solution, the hydrogel fiber by Rukoto to flow along the flow direction of the first aqueous solution It ’s a manufacturing method,
The concentration of the gel-forming substance in the second aqueous solution is set in the range of 0.50% by mass or more and 5.0% by mass or less, and the flow velocity ratio of the first aqueous solution to the second aqueous solution is 0.25 or more and 10 or less. A method for producing a hydrogel fiber, in which the flow rate ratio of the first aqueous solution to the second aqueous solution is set in the range of 0.10 or more and 40 or less. The method for producing a hydrogel fiber according to claim 1, wherein the second aqueous solution is supplied into the first aqueous solution from another pipe provided in the pipe. The method for manufacturing a hydrogel fiber according to claim 2, wherein the other pipe is provided so as to extend and open along the pipe in the pipe. The method for manufacturing a hydrogel fiber according to claim 3, wherein the opening of the other pipe is circular. The method for manufacturing a hydrogel fiber according to any one of claims 2 to 4, wherein the inner diameter of the other pipe is 0.010 mm or more and 5.0 mm or less. The method for producing a hydrogel fiber according to any one of claims 1 to 5 , wherein the hydrogel fiber has a fiber diameter of 1000 μm or less. The method for producing a hydrogel fiber according to any one of claims 1 to 6 , wherein the gel-forming substance is alginate. The method for producing a hydrogel fiber according to any one of claims 1 to 7, wherein the second aqueous solution is supplied to the first aqueous solution so that the outer periphery of the second aqueous solution is covered with the first aqueous solution. A first aqueous solution containing metal ions is circulated in the pipe, and a second aqueous solution containing a gel-forming substance that forms an ion-bridged hydrogel by ion exchange with the metal ions is maintained in the flow direction in the pipe. while after confluence was fed into the first aqueous solution to flow, said first and those are merged a second aqueous solution, hydrogel prepared by Rukoto to flow along the flow direction of the first aqueous solution A method of controlling the fiber diameter of a fiber.
The concentration of the gel-forming substance in the second aqueous solution is set in the range of 0.50% by mass or more and 5.0% by mass or less, and the flow velocity ratio of the first aqueous solution to the second aqueous solution is 0.25 or more and 10 or less. Hydrogel that sets the flow ratio of the first aqueous solution to the second aqueous solution, which has a correlation with the fiber diameter, in the range of 0.10 or more and 40 or less, which corresponds to the target fiber diameter. Fiber diameter control method for fibers.

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