JP7232131B2 - Manufacturing method of gelatin filament yarn - Google Patents

Description

The present invention relates primarily to a method for producing gelatin filament yarns useful for medical applications.

Gelatin is a biocompatible polymer and is used as a structural material for cell culture substrates and temporary replacement of organs during surgery. Conventional gelatin fibers have a low breaking elongation and are easy to break, and long fibers (filament yarns) tend to stick together and are difficult to unwind. It was difficult. Patent Document 1 proposes extruding an aqueous solution containing gelatin and a water-soluble linear polymer such as polyethylene glycol into the air for spinning. Patent Literature 2 proposes jetting a gelatin solution into a coagulation bath to form gel-like fibers, taking them out, stretching them, and removing the remaining solution. Patent Document 3 proposes heating an aqueous gelatin solution to a sol state, spinning in the air, and then immersing it in a cross-linking agent solution for cross-linking.

JP 2012-167397 A JP 2005-120527 A JP 2005-163204 A

However, the long fibers (filaments) made of gelatin fibers obtained by the above-described prior art have been difficult to unwind from, and filaments could not be obtained. In addition, gelatin fibers with high breaking elongation have been proposed by chemically cross-linking gelatin fibers using aldehydes. rice field.

In order to solve the above-mentioned conventional problems, the present invention provides a method for manufacturing a gelatin filament yarn suitable for medical use, in which the wound yarn can be unwound.

The method for producing a gelatin filament yarn of the present invention is a method for producing a gelatin filament yarn from an aqueous gelatin solution ,
When the gelatin aqueous solution is 100% by mass, the gelatin is more than 50% by mass and 70% by mass or less, the water-soluble polymer is not included or the water-soluble polymer is more than 0% by mass and 10% by mass or less . Does not contain a cross-linking component, contains water at a ratio of 30% by mass or more and less than 50% by mass,
The gas-liquid mixture of the gelatin aqueous solution is degassed under reduced pressure to obtain a spinning solution,
By extruding the spinning solution and passing it through a heated spinning cylinder for dry spinning,
A gelatin filament yarn containing gelatin as a main component, containing no water-soluble polymer or containing more than 0% by mass and 10% by mass or less of a water-soluble polymer, containing no chemical cross-linking component, and having a flat and solid cross section. is characterized by obtaining

The gelatin filament yarn of the present invention is a filament yarn containing gelatin as a main component, does not contain a chemical cross-linking component, and has a flat and solid cross section, so that the wound yarn can be unwound and the fabric can be used. , can be processed into knitted fabrics, braided cords, etc. This gelatin filament yarn is suitable for medical applications and the like.

FIG. 1 is a cross-sectional view of a gelatin filament yarn according to one embodiment of the present invention. FIG. 2 is a cross-sectional photograph of the gelatin filament yarn obtained in Example 1, taken with a scanning electron microscope (Hitachi FLEX SEM1000, magnification: 200). FIG. 3 is a side view photograph of the gelatin filament yarn obtained in Example 1, taken with a scanning electron microscope (Hitachi FLEX SEM1000, magnification: 100). FIG. 4 is a schematic illustration of a spinning machine used in one embodiment of the present invention. FIG. 5 is a strength and elongation graph of gelatin filament yarns of Examples and Comparative Examples of the present invention before thermal crosslinking. FIG. 6 is a strength and elongation graph after thermal crosslinking of the gelatin filament yarn of Example 1 of the present invention. FIG. 7 is a side view photograph of a braid of gelatin filament yarns of Example 4 of the present invention. FIG. 8A is a photograph of a gelatin filament yarn of one embodiment of the present invention in a dry state (magnification of 13 times), and FIG. 8B is a photograph of the same in a wet state (magnification of 13 times).

The present invention is a filament yarn containing gelatin as a main component. A main component means 90 mass % or more. Contains no chemical cross-linking components. This is because no harmful substances are added. The filament yarn of the present invention is characterized by having a flat and solid yarn cross section. Although related to the manufacturing method of the present invention, the hot spinning tube is used in the present invention, and the gelatin filament yarn is hollow at the position after exiting this hot spinning tube, and when wound, the hollow is crushed and the cross section is flat. and become solid. The cross-sectional flatness of the gelatin filament yarn is preferably 2 or more in the ratio of major axis/minor axis, more preferably 2.2 or more in the ratio of major axis/minor axis. The gelatin filament thread cross section may have a constriction. Other various flat shapes are included. The flatness of the cross section of the yarn allows the wound yarn to be unwound.

The gelatin filament yarn may be 100 mass % gelatin, or may contain a water-soluble polymer. Incorporation of water-soluble polymer increases elongation and facilitates processing into woven fabrics, knitted fabrics, braided cords, and the like. The water-soluble polymer is preferably polyethylene glycol. The molecular weight of the polyethylene glycol is preferably 500 or more and less than 5000. The amount of polyethylene glycol added is preferably 0.01 to 10% by mass, more preferably 0.1 to 8% by mass, based on the filament yarn.

The filament yarn is white and opaque in appearance when dry, but instantly becomes transparent when wet with water. It is thought that this is caused by the voids between gelatin and polyethylene glycol being filled with water, and when used as a cell culture substrate or a structure for replacing a part of an organ during surgery, wetting of the thread This is a very useful characteristic because the condition can be determined by appearance. Figures 8A-B show external photographs of the dry state and wet state.

The filament yarn preferably has a maximum strength of 0.3 cN/dtex or more and a breaking elongation of 20% or more. If the maximum strength and elongation are within the above ranges, it becomes easy to process into woven fabrics, knitted fabrics, braided cords, and the like. In the above, dtex is an abbreviation of decitex, a term generally used in the industry.

It is preferable that the filament yarn is thermally crosslinked in order to increase the water resistance. Thermal cross-linking is safer than chemical cross-linking in that no cross-linking agent is used. It is preferable that the thermal crosslinking temperature is 100 to 150° C., the heating time is 24 to 96 hours, and the degree of vacuum is 10 kPa or less. Oxidative deterioration at the time of thermal crosslinking can thereby be prevented. When heat-treated in the atmosphere, there is a problem that oxidation deterioration progresses and the physical properties deteriorate. When thermally crosslinked under the above conditions, the water resistance is improved and the polymer becomes difficult to dissolve in water. Thermal cross-linking may be performed on filament yarns, or after processing into woven fabrics, knitted fabrics, braided fabrics, and the like. When processed into woven fabrics, knitted fabrics, braids, etc., it is preferable to thermally crosslink after processing. Due to the thermal cross-linking, the filament yarn maintains its shape even after being immersed in hot water at 37° C. for 20 hours, and is not dissolved.

The manufacturing method of the gelatin filament yarn of the present invention includes the following steps.
(1) A step of adding water to form a gas-liquid mixture of an aqueous gelatin solution so that the gelatin concentration is more than 50% by mass and 70% by mass or less. At this time, a water-soluble polymer such as polyethylene glycol may be added.
(2) Degassing the gas-liquid mixture of the aqueous gelatin solution under reduced pressure to obtain a spinning solution.
(3) A step of extruding the spinning solution and passing it through a heated spinning tube for dry spinning.
(4) A preferred step is a thermal cross-linking step.

In the step (1), gelatin is preferably dissolved in heated water. The melting temperature is preferably 40-90°C. After dissolution, filtration may be performed to remove foreign matter, dust, and the like.
In the step (2), the degree of vacuum during degassing under reduced pressure is preferably 5 to 30 kPa. Thereby, gas (bubbles) can be removed efficiently. It is preferable to keep the temperature at 40 to 90° C. in this step as well.

In the step (3), the spinning solution is also preferably extruded while being kept at 40 to 90°C. It is preferable that the hot spinning tube is maintained at a temperature of 120 to 180° C. and the residence time of the extrudate is 5 seconds or longer. This causes a rapid removal of water from the extrudate to form threads.

The hot spinning tube is vertically oriented. The gelatin filament yarn is hollow at the position after exiting the hot spinning tube, and when it is wound, the hollow is crushed and the cross section becomes flat and solid.

Next, it demonstrates using drawing. FIG. 1 is a trace drawing of a cross-sectional photograph taken with a scanning electron microscope (Hitachi FLEX SEM 1000, magnification 200) of a gelatin filament yarn 1 obtained in an example of the present invention. This gelatin filament yarn 1 is flat and constriction 2 is observed. L1 is the major axis and L2 is the minor axis. This shape was formed by collapsing a hollow center portion during winding. This was confirmed by observing the gelatin filament yarn cut at the bottom of the hot spinning tube. The reason for the hollowness at the position after exiting the hot spinning tube is thought to be that water is rapidly removed in the hot spinning tube. A surface skin layer 3 and an inner core layer 4 are also observed. It is believed that the skin layer 3 was formed by rapidly removing moisture in the hot spinning tube, and the inner core layer 4 was formed by slowly removing moisture.

Comparing Example 1-2 (mixture of polyethylene glycol with gelatin) and Example 3 (100% by mass of gelatin), the behavior up to the maximum strength is common, but 100% by mass of gelatin breaks at the point of maximum strength. put away. However, the composition in which polyethylene glycol is mixed with gelatin maintains a strength of 50% or more of the maximum strength and advances to breaking elongation. It is presumed that the sliding of the oriented molecules probably occurs. The gelatin filament yarn of the present invention thus exhibits unique strength and elongation properties. It is believed that this skin-core structure also contributes to the unwinding of the wound yarn. That is, if the surface is a skin layer, sticking between threads can be prevented.

FIG. 2 is a cross-sectional photograph of a gelatin filament yarn taken with a scanning electron microscope (Hitachi FLEX SEM1000, magnification: 100 times), and FIG. 3 is a side photograph of the same.

FIG. 4 is a schematic illustration of the filament manufacturing apparatus 10 used in one embodiment of the present invention. A spinning solution 12 of an aqueous gelatin solution contained in a syringe 11 is extruded from a nozzle 13 into the air. Nozzle 13 may be of normal circular cross-section. A heated spinning tube 14 is directly connected to the bottom of the nozzle 13 . The heated spinning tube 14 is composed of four sections 14a to 14d, and the temperature of each section can be controlled. The obtained gelatin filament thread 15 passes through a guide roll 16 and is wound on a winder 17 .

A more specific description will be given below using examples. In addition, the present invention is not limited to the following examples.
The measuring method is as follows.
<Filament thread cross section>
It was observed with a photograph of a scanning electron microscope (Hitachi FLEX SEM 1000 type, magnification 500 times).
<Others>
It was measured according to the measurement method prescribed by JIS or the industry.

(Example 1)
Nitta Gelatin Co., Ltd. (jelly strength: 262 g raw material: alkali-treated bovine bone) was used as gelatin. The mixture was heated to 0° C. and dissolved, and defoamed under a vacuum of 10 kPa to obtain a spinning dope.
This spinning dope is filled in a resin syringe, a resin nozzle with an inner diameter of 0.61 mm is attached, the syringe is placed in a heat insulating holder, the temperature is adjusted to 57°C, and pressurized air of 0.1 MPa is sent from the end of the syringe to the dope through the nozzle. pushed out.
The undiluted solution extruded from the nozzle is passed from the top through a heated spinning tube with a length of 2 m, in which a heater is wrapped around a stainless steel tube with an inner diameter of 200 mm, which is installed vertically, and dried by heating at a temperature of 150 ° C. At the outlet of the lower end, the speed is 10 m. /min. The residence time was 12 seconds.
The obtained gelatin monofilament yarn was allowed to stand in an environment of 20° C. and 65% RH for 24 hours, and then was subjected to JIS-L1013 method using Autograph ASX-G manufactured by Shimadzu Corporation with a sample length of 100 mm and a tensile speed of 100 mm/min. Tensile strength and elongation at break were measured according to the standards. The fineness of the yarn was calculated by measuring the weight of a filament yarn having a length of 10 m and converting it to 10000 m. The filament thread shape was observed with an optical microscope.
Ten samples of the obtained monofilament yarn had average strength and elongation properties of fineness of 357 dtex, maximum strength of 123 cN, strength per fineness of 0.34 cN/dtex, and elongation at break of 42.6%. Also, the cross-sectional shape of the fiber was flat and constricted as shown in FIG. 1-2. The major axis L1 of the fiber cross section was 0.283 mm, the minor axis L2 was 0.121 mm, and the major axis/minor axis was 2.34. Since this monofilament yarn was flat and constricted, the wound filament yarns did not stick together and could be continuously unwound. A strength and elongation graph close to the strength and elongation average value of this monofilament yarn is shown in FIG. Also, the gelatin filament yarn of Example 1 was thermally crosslinked at 140° C. for 48 hours at a degree of vacuum of 1 kPa. Before thermal cross-linking, it dissolved when immersed in warm water of 37°C for 20 hours, but after thermal cross-linking, it maintained its shape and did not dissolve even when immersed in warm water of 37°C for 20 hours. From this, it has been confirmed that the water resistance is improved and the composition becomes less soluble in water.
The average strength and elongation properties of 10 samples of the monofilament yarn after treatment were 129.6 cN maximum strength, 0.36 cN/dtex per fineness, and 8.5% elongation at break. FIG. 6 shows a strength and elongation graph close to the strength and elongation average value of the monofilament yarn after thermal cross-linking. Compared to the non-thermally crosslinked gelatin filament yarn of Example 1 in FIG. 5, the tensile strength was slightly higher, but the elongation was significantly lower. This is considered to be due to the progress of cross-linking.

(Example 2)
A gelatin monofilament yarn was obtained by adjusting the solution and spinning in the same manner as in Example 1 except that 58.2 g of gelatin and 1.8 g of polyethylene glycol (molecular weight: 1000) were used. Ten samples of the obtained monofilament yarn had average strength and elongation properties of fineness of 310 dtex, maximum strength of 100 cN, strength per fineness of 0.32 cN/dtex, and elongation at break of 22.4%. The cross-sectional shape of the fiber was flat, and depressions were observed on the surface. The major axis L1 of the fiber cross section was 0.273 mm, the minor axis L2 was 0.103 mm, and the major axis/minor axis was 2.65. Since this monofilament yarn was flat and constricted, the wound filament yarns did not stick together and could be continuously unwound. A strength and elongation graph close to the strength and elongation average value of this monofilament yarn is shown in FIG.
The gelatin filament yarn of Example 2 was thermally crosslinked at 140° C. for 48 hours at a degree of vacuum of 1 kPa. Before thermal cross-linking, it dissolved when immersed in warm water of 37°C for 20 hours, but after thermal cross-linking, it maintained its shape and did not dissolve even when immersed in warm water of 37°C for 20 hours. From this, it has been confirmed that the water resistance is improved and the composition becomes less soluble in water.

(Example 3)
The procedure was carried out in the same manner as in Example 1, except that polyethylene glycol was not added. Since this monofilament yarn was flat and constricted, the wound filament yarns did not stick together and could be continuously unwound. Ten samples of the obtained monofilament yarn had average strength and elongation properties of fineness of 306 dtex, tensile strength of 79 cN, strength per fineness of 0.26 cN/dtex, and elongation at break of 1.1%. A strength and elongation graph close to the strength and elongation average value of this monofilament yarn is shown in FIG. The cross-sectional shape of the fiber was flat, and the major axis L1 of the fiber cross section was 0.250 mm, the minor axis L2 was 0.095 mm, and the major axis/minor axis was 2.63.
The gelatin filament yarn of Example 3 was thermally crosslinked at 140° C. for 48 hours at a degree of vacuum of 1 kPa. Before thermal cross-linking, it dissolved when immersed in warm water of 37°C for 20 hours, but after thermal cross-linking, it maintained its shape and did not dissolve even when immersed in warm water of 37°C for 20 hours. From this, it has been confirmed that the water resistance is improved and the composition becomes less soluble in water.

(Comparative example 1)
A spinning solution prepared in the same manner as in Example 1 was used to wind a monofilament yarn at room temperature without using a heated spinning tube during spinning. The cross-sectional shape of the monofilament thread became circular (solid), and the wound filament thread was agglutinated and could not be released, failing to obtain long fibers.
The above results are summarized in Table 1. The data in Table 1 are the data one day after spinning (no thermal cross-linking) and are the average values of 10 measurements.

As shown in Table 1, the gelatin filament yarns of Examples 1 to 3 were yarns capable of being unwound from a wound yarn. It has also been confirmed that this thread can be processed into woven fabrics, knitted fabrics, braided cords, and the like.

(Example 4)
Using 16 monofilament yarns obtained in Example 1, a braid was produced. The resulting braid had a cylindrical shape with an inner diameter of 0.5 mm and an outer diameter of 0.9 mm, and could maintain a stable shape. FIG. 7 is a side view photograph of the braid of this gelatin filament yarn.

The gelatin filament yarn of the present invention is suitable for practical production because wound filament yarns do not stick together and can be continuously unwound. It also has strength and elongation, and can be processed into woven fabrics, knitted fabrics, braided cords, and the like. The woven fabric, knitted fabric, braided cord, etc. are useful for artificial blood vessels, stents for intestinal tracts, and the like. In addition, by processing it into fiber structures such as woven fabrics, knitted fabrics, and braids, it is useful for medical materials such as wound dressings, protective and support materials during surgery, and regenerative medicine substrates such as cell culture substrates. be. Furthermore, thermal cross-linking improves water resistance.

Reference Signs List 1, 15 Gelatin filament thread 2 Constriction 3 Surface skin layer 4 Inner core layer 10 Filament production device 11 Syringe 12 Spinning solution 13 Nozzle 14 Hot spinning tube 16 Guide roll 17 Winding machine

Claims (13)

A method for producing a gelatin filament yarn from an aqueous solution containing gelatin, comprising:
When the aqueous solution containing gelatin is taken as 100% by mass, the gelatin is more than 50% by mass and 70% by mass or less, and the water-soluble polymer is not included or the water-soluble polymer is more than 0% by mass and 10% by mass or less . , does not contain a chemical cross-linking component, contains water in a proportion of 30% by mass or more and less than 50% by mass,
degassing the gas-liquid mixture of the gelatin-containing aqueous solution under reduced pressure to obtain a spinning solution;
By extruding the spinning solution and passing it through a heated spinning cylinder for dry spinning,
A gelatin filament yarn containing gelatin as a main component, containing no water-soluble polymer or containing more than 0% by mass and 10% by mass or less of a water-soluble polymer, containing no chemical cross-linking component, and having a flat and solid cross section. A method for producing a gelatin filament yarn, characterized by obtaining 2. The method for producing a gelatin filament yarn according to claim 1, wherein the heated spinning tube has a temperature of 120 to 180° C. and a retention time of the extrudate is 5 seconds or longer. 3. The method for producing a gelatin filament yarn according to claim 1 or 2, wherein the heat spinning tube is oriented vertically. 4. The production of the gelatin filament yarn according to any one of claims 1 to 3, wherein the gelatin filament yarn is hollow at the position after exiting the hot spinning tube, and when wound, the hollow is crushed and the cross section is flattened. Method. 5. The filament yarn according to any one of claims 1 to 4, wherein the filament yarn is further thermally crosslinked at a temperature of 100 to 150°C, a heating time of 24 hours to 96 hours, and a degree of vacuum of 10 kPa or less. A method for producing a gelatin filament yarn. The method for producing a gelatin filament yarn according to any one of claims 1 to 5 , wherein the gelatin filament yarn has a cross-sectional flatness of 2 or more in terms of major axis/minor axis. The method for producing a gelatin filament yarn according to any one of claims 1 to 6 , wherein the gelatin filament yarn cross section has a constriction. The method for producing a gelatin filament yarn according to any one of claims 1 to 7 , wherein the water-soluble polymer is polyethylene glycol. 9. The method for producing a gelatin filament yarn according to claim 8 , wherein the polyethylene glycol has a molecular weight of 500 or more and less than 5000. 10. The method for producing a gelatin filament yarn according to claim 8 or 9, wherein the amount of polyethylene glycol added is 0.01 to 10% by mass relative to the filament yarn. 11. The filament yarn according to any one of claims 1 to 10, wherein the appearance of the filament yarn is white and opaque in a dry state, but when it is wetted with water and is in a wet state, it instantly becomes transparent, and the wet state can be determined by the appearance . A method for producing the gelatin filament yarn according to the above item . The production of the gelatin filament yarn according to any one of claims 1 to 11 , wherein the filament yarn is further thermally crosslinked, and due to the thermal crosslinking, it maintains its shape and does not dissolve even when immersed in hot water at 37°C for 20 hours. Method. The method for producing a gelatin filament yarn according to any one of claims 1 to 12 , wherein the strength-elongation curve of the gelatin filament yarn has an elongation to breaking elongation after maximum strength of 10% or more.

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