WO2003100144A1

WO2003100144A1 - Biocompatible core-shell composite fiber, biocompatible synthetic fiber and method for production thereof

Info

Publication number: WO2003100144A1
Application number: PCT/JP2003/006438
Authority: WO
Inventors: Kozo Tsubouchi; Hideki Ishikawa
Original assignee: National Institute Of Agrobiological Sciences; Shinwa Corp.
Priority date: 2002-05-23
Filing date: 2003-05-23
Publication date: 2003-12-04
Also published as: AU2003242411A1; JP3855162B2; JP2003342835A; AU2003242411A8

Abstract

A biocompatible core-shell composite fiber, wherein its core material comprises a thermoplastic synthetic polymer and its shell material comprises a silk powder being substantially free of particles having a particle diameter of more than 10 μm and a thermoplastic synthetic polymer having a melting point of 200°C or lower; and a biocompatible fiber which comprises a silk powder being substantially free of particles having a particle diameter of more than 10 μm and a thermoplastic synthetic polymer having a melting point of 200°C or lower. The fiber contains a thermoplastic synthetic polymer as its main component and exhibits excellent biocompatibility and silk-like gloss, feeling, moisture holding property and the like. Although it contains a considerable amount of a silk powder, it is reduced in the lowering of strength and exhibits satisfactory strength in practical use.

Description

Description Biocompatible core-sheath composite fiber, biocompatible synthetic fiber and method for producing the same

(Technical field to which the invention belongs)

TECHNICAL FIELD The present invention relates to a synthetic fiber produced from a thermoplastic synthetic polymer containing silk powder, and particularly to a synthetic fiber having excellent biocompatibility and excellent durability and moldability. Background art

(Conventional technology)

In general, silk has an extremely high gloss and soft texture, and also has excellent moisture absorption and desorption properties.Therefore, it cannot be used as a high-grade clothing material. It can be called a material.

In addition, due to its biocompatibility, new uses are spreading for medical materials such as sutures and cosmetics.

However, at present, the supply of silk is limited and the cost is very expensive, so it is impossible to meet the demand at present.

Under these circumstances, research and development to obtain alternative materials, such as fibers and films, which have properties very close to silk, have been actively conducted in recent years.

For such research and development, there is a method of imparting silky-feeling properties and the like by mechanical treatment of synthetic fiber / film.

In addition, the surface of products such as synthetic fibers, non-woven fabrics and films may contain silk proteins. A method of imparting silk properties by chemically modifying it with a treating agent, a method of adding silk powder to a thermoplastic synthetic polymer, and imparting the properties of silk to a molded article of the thermoplastic synthetic polymer, etc. Has been proposed.

In the latter method, in which the surface of a product such as synthetic fiber, non-woven fabric, or film is chemically modified with a silk protein-containing treating agent to impart silk properties, a silk protein aqueous solution ( An example using (dispersion) is, for example,

Japanese Patent Application Laid-Open No. Hei 3 — 1 2 3 5 6 1

Japanese Patent Application Laid-Open No. Hei 4 — 009975,

Japanese Utility Model Publication No. 6 — 3 7 3 9 7

Japanese Patent Application Laid-Open No. Hei 9 — 1 3 7 3 8 1,

Japanese Patent Application Laid-Open No. 9-144, 876,

Japanese Patent Application Laid-Open No. 9-1889872,

Japanese Patent Application Laid-Open No. 9-311 428,

Japanese Patent Application Laid-Open No. Hei 9 — 3 2 291 1

Japanese Patent Application Laid-Open No. 10-18772

Etc.

Examples of using a dispersion of a silk protein aqueous solution with a binder added as a treating agent include:

For example,

Japanese Patent Application Laid-Open No. 9-31 8 4 7

Japanese Patent Application Laid-Open No. Hei 9 — 1 2 4 7 9 6

Japanese Patent Application Laid-Open No. H10-212124456

Etc.

In addition, examples of using a mixture of silk powder with a binder or paint as a treating agent include: For example,

Japanese Patent Laid-Open No. 3-513070,

Japanese Patent Application Laid-Open No. Hei 5 — 7 8 9 7 9

Unexamined Japanese Patent Publication No.

JP-A-6-370672,

Japanese Patent Application Laid-Open No. Hei 7 — 5 4 2 7 7

Japanese Patent Application Laid-Open No. 7-2790953,

Japanese Patent Application Laid-Open No. Hei 9-111188,

Japanese Patent Application Laid-Open No. Hei 9 — 217092,

Japanese Patent Application Laid-Open No. 2000-4404598

Etc.

In the methods described above, the properties of silk protein can be generally imparted to the material surface, but in the method using a silk protein aqueous solution (dispersion solution) as a treating agent, silk protein uses fibers. It has the drawback that it easily falls off during or during cleaning and has poor durability.

When silk protein is mixed with a binder or paint as a treating agent, the silk protein is prevented from falling off the material surface and durability is improved, but the binder or paint covers the silk protein. As a result, there is a problem that the function of the silk screen cannot be fully exhibited. Silk fabric has no thermoplastic properties and will decompose and carbonize until heated when heated, but as mentioned earlier, silk has excellent luster, texture, moisture absorption, moisture absorption, etc. In particular, it has biocompatibility as a property not found in thermoplastic synthetic polymers.

Incidentally, it has recently been found that silk protein has the property of promoting the growth of human-derived skin cells as one of the functions of biocompatibility. On the other hand, in the method in which the silk protein is contained in the thermoplastic synthetic polymer, the loss of the silk protein during use or washing is reduced, but the contained silk protein becomes a mechanical weak point. However, it causes a decrease in the strength of the fiber.

In particular, it is necessary to reduce the size of the silk protein particles extremely, since the decrease in strength with respect to tensile strength is large.

Conventionally, silk protein particles are too large, and the tensile strength is drastically reduced. So far, silk protein-containing thermoplastic synthetic polymers have not been used.

Specific examples of the method of adding silk powder to the thermoplastic synthetic polymer and imparting the properties of silk to the molded article of the thermoplastic synthetic polymer include, for example,

Japanese Patent Application Laid-Open No. 2-195095,

Japanese Patent Application Laid-Open No. Hei 7 — 2 7 8 4 41,

JP-A-9-1118756, JP,

JP-A-9-12798939,

Japanese Patent Application Laid-Open No. H10-10-2 1 2 4 17

And the like.

These are mainly concerned with a film or sheet-like molded body, but only in the above-mentioned Japanese Patent Application Laid-Open No. 10-212417, a fiber is produced by a melt spinning method or the like.

Japanese Patent Application Laid-Open No. H10-212124 / 17 discloses that the surface of a silk powder having an average particle diameter of 20 to 50 μm has an average particle diameter of 0.2 to improve the heat resistance of the silk powder. M0.3 m of titanium oxide was pressed and adhered, mixed with thermoplastic resin, spun at a spinning temperature of 270 ° C, and the titanium oxide-containing silk powder was evenly distributed in the fiber. Can get synthetic fiber Points are shown.

However, since silk powder, which has a large average particle diameter of 20 to 50 m, is used, the fiber used for ordinary clothes has a diameter of 100 m or less, especially 30 m or less. In the case of producing synthetic fibers, the presence of silk powder having a large average particle diameter of 20 to 50 m significantly lowers the tensile strength of the fibers, making them virtually unusable as fibers. You can only get what you can.

In addition, the above spinning temperature of 270 ° C is much higher than the decomposition temperature of silk protein, and at such a temperature, the silk protein is carbonized, so that the original characteristics of silk protein can be utilized. There is a problem that you can not.

(Problems to be solved by the invention)

An object of the present invention is to provide a new material excellent in biocompatibility, particularly a fiber, which has a silky luster, texture, moisture retention and the like, and is mainly composed of a thermoplastic synthetic polymer.

Another object of the present invention is to provide a new biocompatible material that can withstand practical use with a small decrease in the strength of the synthetic fiber even when the synthetic fiber made of a thermoplastic synthetic polymer contains silk powder. .

The present invention also develops a low-cost fiber having both functions by using a high-priced biocompatible silk protein and a low-priced thermoplastic synthetic polymer having excellent durability and moldability. The purpose is to: Disclosure of the invention

(Means for solving the problem)

In order to solve the above problems, the present inventors have developed a thermoplastic synthetic polymer. As a result of extensive research into obtaining biocompatible synthetic fibers that can fully demonstrate the properties of the silk protein and that are durable, as a result of at least the core-sheath structure and silk powder The present inventors have found that the particle size and the melting point of the thermoplastic synthetic polymer are important factors, and have completed the present invention based on this finding.

That is, according to the present invention, (1) the core material is made of a thermoplastic synthetic polymer, the sheath material is a silk powder substantially free from powder particles having a particle diameter exceeding 10 βm, and the melting point is 200 °. It is a biocompatible core-sheath composite fiber made of a thermoplastic synthetic polymer of C or less.

(2) The biocompatible core-sheath composite fiber in which the content of the silk powder in the sheath material is 5 to 50% by weight of the total amount of the silk powder and the thermoplastic synthetic polymer.

Also, (3) the biocompatible core-sheath type conjugate fiber in which the content of the silk powder in the sheath material is 10 to 30% by weight of the total amount of the silk powder and the thermoplastic synthetic polymer. .

Further, (4) the thermoplastic synthetic polymer constituting the core material and the thermoplastic synthetic polymer constituting the sheath material are present in the same thermoplastic synthetic polymer as the biocompatible core-sheath composite fiber.

(5) The thermoplastic synthetic polymer constituting the core material and the thermoplastic synthetic polymer constituting the sheath material are present in biocompatible core-sheath type composite fibers which are different thermoplastic synthetic polymers.

And (6) a biocompatibility characterized in that the powder is made of a silk powder substantially free of particles having a particle diameter exceeding 10 m and a thermoplastic synthetic polymer having a melting point of 200 ° C. or less. Present in synthetic fibers.

(7) The biocompatible synthetic fiber having a silk powder content of 5 to 50% by weight of the total amount of the silk powder and the thermoplastic synthetic polymer. Exist.

(8) The biocompatible synthetic fiber wherein the content of the silk powder is 10 to 30% by weight of the total amount of the silk powder and the thermoplastic synthetic polymer.

And (9) the biocompatible core-sheath type composite fiber or the biocompatible synthetic fiber in which the thermoplastic synthetic polymer is an olefin polymer.

Also, (10) the biocompatible core-in-sheath type composite fiber or the biocompatible synthetic fiber in which the olefin-based polymer is polyethylene, polypropylene or a copolymer mainly composed of these.

Also, (11) a biocompatible core-sheath composite fiber or a biocompatible synthetic fiber having a fiber diameter of 5 to 100 m, preferably 10 to 30 m.

And (12) a biocompatible core-sheath composite fiber obtained by subjecting a core material made of a thermoplastic synthetic polymer and a sheath material made of silk powder and a thermoplastic synthetic polymer to core-sheath composite spinning and stretching. Lies in the manufacturing method.

(13) a core material comprising a thermoplastic synthetic polymer; a silk powder substantially free from powder particles having a particle diameter of more than 10 μm; and a thermoplastic material having a melting point of 200 ° C. or less. The present invention relates to a method for producing a biocompatible core-in-sheath type composite fiber in which a sheath material made of a synthetic polymer is subjected to core-sheath composite spinning and stretching.

Further, (14) a powder having substantially no particle diameter exceeding 10 nm, a silk powder substantially free from particles, and a thermoplastic synthetic polymer having a melting point of 200 ° C. or less are mixed, heated and kneaded. And then spinning and stretching.

And (15) mixing silk powder and thermoplastic synthetic polymer. When heating, kneading, and then melt-spinning, the step of melting and extruding from a spinneret should be performed at a temperature of 200 ° C or less and for a time of 6 minutes or less. A method for producing biocompatible synthetic fibers.

The present invention also employs a configuration combining two or more selected from the above 1 to 5, 6 to 8, 9 to 11, and 12 to 15 as long as the purpose is met. It is possible.

(The invention's effect)

The biocompatible core-sheath type composite fiber and the biocompatible synthetic fiber of the present invention have silk-like luster, texture, moisturizing property, etc., and are excellent in durability, and are suitable for clothing materials and medical materials. Useful. BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a photomicrograph of the double-layered fiber of Example 3 of the present invention.

FIG. 2 shows a polarizing microscopic photograph of a fiber having a two-layer structure of Example 3 of the present invention.

BEST MODE FOR CARRYING OUT THE INVENTION

(Embodiment of the invention)

The types and characteristics of each raw material, the manufacturing conditions, and the like for specifically implementing the present invention will be described below.

[1] Silk powder raw material

The raw material of silk protein is cocoon thread, raw silk, silk woven or knitted fabric, silk thread (fiproin fiber), their remaining yarn or their unscrambled, semi-scrambled, refined It can be applied to kneaded materials, and fibers, powders, films, etc. made from them, protein fibers spun by silkworms such as silkworms and wild silkworms, and all of their remnants.

In general, silkworms secrete silk into the silk gland cavity of the body, and this silk is called liquid silk.

Liquid silk consists of fibrin and sericin (these are called silk powders), and liquid fiber mouth has a molecular weight of about 370,000 [Tasiro Yutak and Otsuki Eiichi, Journal of Cell Biology, Vol. 46, P. 1 (1

970)) o

In addition, a fiber mouth with a molecular weight of about 370,000 is divided into a molecular weight of about 350,000 (H chain) and about 25,000 (L chain).

Cocoons (consisting of so-called cocoons and pupae) are formed when silkworms spit liquid silk during cocoon production.

It is known that the cocoon contains fibrin at the center and sericin around it, and the abundance ratio is (70-80% fibrous mouth): 30-20% (sericin). Have been.

By the way, raw silk is made by assembling several to several tens of cocoons, and a woven fabric made of raw silk is called raw woven.

The process of removing sericin from cocoon, raw silk or raw weave is called scouring, and the fibers after scouring are silk or fiproin fibers.

The silk thread is produced by first drying the grown cocoon and then winding it after boiled cocoon to produce raw silk.

Next, raw silk or raw weave is refined to obtain silk yarn or silk fabric. The waste generated in these steps is the residual yarn.

[2] Silk powder

(1) Crystalline silk powder The crystalline silk powder is produced, for example, according to a method for producing a crystalline silk ultrafine powder as disclosed in JP-A-2001-48989. The particle size of silk powder is generally represented by the average particle size, but there is a distribution in the particle size, and the size of the powder is such that particles having a smaller average particle size and larger particles are widely distributed.

For example, even if the average particle size is 5 m, it is normal that a large powder of about 20 m is slightly contained.

In the case of the present invention, the average particle diameter is also focused on the value of the maximum particle diameter in consideration of the fact that the larger the powder, the lower the tensile strength.

Unless particles having a particle diameter exceeding a certain limit are separated, the desired silk powder-containing resin cannot be spun, especially drawn.

From this viewpoint, the powder obtained by the production method of the aforementioned Japanese Patent Application Laid-Open No. 2001-48989 is pulverized and classified to obtain a powder having a particle diameter of more than 10 m, more preferably 5 i / Those exceeding m are separated and removed.

That is, powders having a particle size of more than 10 μm, more preferably powders having a particle size of more than 5 μm are not included.

Further, the particle diameter is preferably 110 or less of the fiber diameter (that is, the fiber formed by spinning and drawing).

On the other hand, if the particle size is too small, the powder is likely to be buried in the fiber, and it is true that the buried powder does not function as a silk powder.

From this viewpoint, regarding the minimum particle diameter, the particle diameter of the powder is preferably 0.1 m or more, and more preferably 0.5 / m or more.

From this, the average grain size is considered in consideration of the sharpness of grinding and classification. The diameter of the silk powder is preferably 0.5 m or more and 5 m or less.

(2) Amorphous silk powder

Non-crystalline silk powder is disclosed in Japanese Patent Application Laid-Open No. 11-170160 (Wound dressing material containing silk fiplin and silk sericin as a main component and a method for producing the same). — 1 639 9 9 (Method of producing functional silk fiproin and its use), Japanese Patent Application Laid-Open No. 2002-122628 (1) Sericin-containing material, method of its production and It is manufactured according to a method such as that described in Japanese Patent Application No. 2001-180169 (a method for producing and using a functional polypeptide derived from silk fibrin).

The non-crystalline silk powder is also crushed and classified like the above-mentioned crystalline silk powder to obtain a powder having a particle diameter of more than 10 βm, preferably a powder having a particle diameter of more than 5 removed.

The minimum particle size of the powder is preferably 0.1 m or more, more preferably 0.5 / m or more.

(3) Silk powder particle size

As described above, regarding the maximum particle size of the powder, from the viewpoint of spinnability, it does not substantially include a powder having a particle size exceeding 10 m, and more preferably does not include a powder having a particle size exceeding 5 μm. To do.

In the case of pulverization and classification, particles of 10 β m or more may be included, but the degree does not matter.

On the other hand, the minimum particle diameter of the powder is preferably 0.1 m or more, more preferably 0.5 m or more, as described above, from the viewpoint of being easily buried in the fiber. .

(4) Biocompatibility of silk powder

Since there is an intention of developing skin care materials in the underflow of the present invention, The biocompatibility of the silk powder in the present invention means that the silk powder does not adversely affect the growth of human skin cells.

The present inventors have already conducted a biochemical study on silk powder, and found that silk fiber mouth has an effect of promoting the growth of human cells. (Japanese Patent Application Laid-Open Nos. 9-1192210 and 111-125315)

) o

It has been clarified that the action is present in the H-chain and the L-chain of the fiber mouth constituting silk fiber mouth (Japanese Patent Application Laid-Open No. 2001-169389). , Japanese Patent Application No. 2001-1801.169).

Further, it has been clarified that a component of silk sericin has a human cell growth promoting property (Japanese Patent Application Laid-Open No. 2002-128691).

Although such silk powder is said to be excellent in biocompatibility, it is easily decomposed by heat, light, acid, alkali, etc., and its molecular weight is reduced. Incidentally, such a decrease in molecular weight leads to a decrease in the viability of human cells, and an extremely decrease in the molecular weight also causes inhibition of cell growth.

[3] Thermoplastic synthetic polymer

Examples of the thermoplastic synthetic polymer constituting the biocompatible core-sheath type composite fiber or the biocompatible synthetic fiber of the present invention include polyethylene (PE) and polypropylene (melting point: 200 ° C. or less). Polyolefin-based (co) polymers such as PP) and aliphatic polyesters can be used.

Examples of the polyethylene-based copolymer include a copolymer of ethylene and —olefin having 3 to 20 carbon atoms, an ethylene-acrylic acid ester copolymer, and a copolymer of ethylene and α-carbon having 3 to 20 carbon atoms. —A copolymer with ethylene, and preferably a copolymer of ethylene and a one-year-old fin having 3 to 10 carbon atoms is used. Examples of comonomer «— olefins include propylene, butene

— 1, pentene-1, hexene-1, 4-methylpentene1-1, heptene-1, octene1-1, decene-1, etc. Of these, butene-1, hexene-1,

These comonomer α-olefins may be used alone or in combination of two or more.

Aliphatic polyesters include polylactic acid, poly-3-hydroxypropionate, poly-3-hydroxybutyrate, poly-13-hydroxybutyrate, poly-ε-force prolact Among them, polylactic acid, which is a biodegradable polymer, is particularly preferred.

The lower limit of the melting point of the aliphatic polyester is 70 ° C. from the viewpoint of ensuring sufficient heat resistance and maintaining good spinnability.

In addition, polyesters such as polyethylene phthalate and polyethylene terephthalate, and condensation polymers such as nylon and polyurethane may be added with other low-softening point polymers and plasticizers. It can be used as a polymer composition having a softening point of 0 ° C or less.

In addition, the above-mentioned thermoplastic synthetic polymers may include, if necessary, antibacterial agents, antifungal agents, light stabilizers such as ultraviolet absorbers and infrared absorbers, antioxidants, dewatering agents, and antistatic agents. Various additives such as a flame retardant, a colorant, a dye, and a conductive agent may be contained.

[4] Silk powder-containing belt

To make silk powder-containing fibers, first, a pellet is made by mixing silk powder and a thermoplastic synthetic polymer.

The mixing ratio of the silk powder (the weight ratio of the thermoplastic synthetic polymer of the silk powder) is 5 to 50% by weight, preferably 10 to 30% by weight.

When making mixed pellets, the weight percentage of silk powder is If it is more than 50% by weight, it is difficult to mix with each other at the time of mixing, so that kneading cannot be performed.

On the other hand, if the proportion of the silk powder is less than about 5% by weight, the function of the silk powder does not work sufficiently.

[5] Spinning method

(1) Examples of the spinning method include a wet spinning method, a dry spinning method, and a melt spinning method. In the present invention, it is desirable to use a melt spinning method.

Generally, the higher the spinning temperature is, the better the spinnability of the thermoplastic synthetic polymer is. However, if the temperature is too high, the thermoplastic synthetic polymer is thermally decomposed. In other words, thermoplastic synthetic polymers have the appropriate spinning temperature, respectively.Since silk powder is too hot, it decomposes to lower molecular weight, so it has a lower melting point than PE and PP among thermoplastic synthetic polymers. The resin is particularly desirable.

In spinning a thermoplastic synthetic polymer, the heat of the spinning solution causes decomposition of the silk powder.

For example, in air at 1 atm, yellowing tends to occur in about 6 minutes above 200 ° C, and from yellow to brown in about 5 minutes above 230 ° C, Above about 250 ° C, carbonization starts easily within 5 minutes.

The yellowed or brownish silk powder inhibits human skin cell growth.

In the case of spinning, the maximum temperature is usually about 3 to 6 minutes, so it is preferable to adopt a temperature range that does not cause any problem even if heating is performed for at least 6 minutes.

Silk powder adversely affects human skin cell growth due to melting and heating during spinning The effect begins when the heat treatment is performed at a temperature not exceeding 200 ° C, which is a temperature range in which heating for 6 minutes does not cause any problem.

Therefore, it is understood that a thermoplastic synthetic polymer having a melting point of 200 ° C. or less is preferable.

If the temperature is low, yellowing and thermal decomposition can be avoided. For example, it is about 20 minutes at 180 ° C and about 60 minutes at 150 ° C.

(2) When spinning a silk-powder-containing thermoplastic synthetic polymer by a melt spinning method, it is necessary to prevent a decrease in tensile strength in order to ensure the usability as a spun fiber.

On the other hand, only the silk powder present on the surface of the fiber contributes to skin care, and small silk powder that does not appear on the surface of the fiber only causes a decrease in tensile strength. Less is preferred.

From the viewpoint of not lowering the tensile strength of the fiber and localizing the silk powder near the fiber surface, the fiber having a double-layered structure having a core and a sheath maintains the tensile strength and is made of silk. This enabled the powder to be localized near the fiber surface.

The tensile strength of the fiber can be sufficiently borne by the core, and the decrease in strength due to the inclusion of the silk powder can be minimized.

Further, just in case, from the viewpoint of minimizing a decrease in the strength of the sheath portion containing the silk powder, it is preferable to use a silk powder containing no powder particles exceeding at least 10 βm.

Incidentally, even in the case of a single structure having no two-layer structure consisting of a core and a sheath, it is preferable to use a silk powder containing no powder particles of at least 10 m.

In the present invention, the silk powder in the sheath portion is more Localization is more effective because it comes to the surface.

The silk powder is physically retained by being immobilized on the surface of the fiber by the thermoplastic synthetic polymer and does not fall off during use.

As a method of spinning a two-layer structure fiber, a pellet is prepared by mixing a thermoplastic synthetic polymer and silk powder, and this pellet is used as a sheath, and is spun at the same time as the core thermoplastic synthetic polymer.

Of course, no silk powder is mixed into the core.

[6] Synthetic fiber

In the present invention, a diameter of 5 to 100 im, which is generally used as clothing, is preferable.

Manufacture synthetic fibers of about 10 to 30 m.

In a synthetic fiber having a two-layer structure of a core-sheath, the diameter of the synthetic fiber is a + 2b when the diameter of the core is a and the thickness corresponding to the sheath is, but the ratio of a to 2b is 5 ~ 95 to 95-5, preferably 30-80 to 70-20.

The thermoplastic synthetic polymers of the core and sheath may be the same or different.

Hereinafter, examples of the present invention will be described, but the present invention is not limited only to those examples.

[Example 1]

(Production of silk powder)

Using the method described in Japanese Patent Application Laid-Open No. 2001-48989 (a method for producing ultrafine crystalline silk), a silk powder was produced as follows.

The silkworm silk is boiled for one hour in a 0.1% aqueous sodium carbonate solution 50 times the volume of the silkworm and refined to obtain fibrin fibers (silk thread). g, add 5 g of sodium carbonate, and add approximately 120 ° C (2 Pressure) for 2 hours, washed with water and dried.

Next, this silk material is ground with a stirring and crushing device (Ishikawa type), and then crushed with a rotary impact crusher [Sample Mill KI-1 manufactured by Fuji Electric Industries Co., Ltd.]. It was pulverized with a current grinder [current jet CJ-10 manufactured by Nisshin Flour Milling Co., Ltd.].

The obtained silk powder (A) was distributed in the range of 0.3 ^ m to 9.3 μτη, and the average particle size was 3.2 μm.

When the particles were crushed and classified again by an air-flow crusher to remove particles of 5 / m or more, the silk powder (B) was distributed from 0.8 μm to 4.6 μm, and the average particles were The diameter was 2.5 / m.

[Example 2]

(Heat treatment of silk powder and promotion of cell growth)

The silk powder (B) obtained in Example 1 was subjected to dry heat treatment.

Dry heat treatment was performed using Clsuzu Manufacturing (Thenno-Regulator)] at (2) 180 ° C and (3) 190. C, (4) 200 ° C, (5) 210. At each temperature of C, the silk powder placed in a petri dish was placed for 6 minutes and subjected to a dry heat treatment.

The silk powder dried and heat-treated at 210 ° C. turned yellow.

The powder not subjected to the dry heat treatment was (1) brought to room temperature.

The cell viability of (1) to (5) was measured as follows. 0.5 mg of each of the silk powders (1) to (5) was placed in a 2 ml cell culture medium, and about 70,000 cells were inoculated into the medium and cultured for 3 days.

The cells used were normal human adult skin fibroblasts [KF-410 (Kurashiki Spinning Co., Ltd.)], and the medium used was a low serum freezing medium for fibroblast proliferation [M edium 106 S, LSGS, PSA solution (manufactured by Kurashiki Boseki Co., Ltd.)] was used.

Cultivation is performed on a single culture dish containing the silk powder of (1) to (5). 2 ml of the culture medium was added, and 70,000 cells were inoculated therein and cultured for 3 days.

The number of cells was determined by adding 2 ml of medium and 0.1 ml of Alama Blue (IWAKI) per dish to the plate, and calculating the absorbance at 570 nm and 600 nm after 2 hours at 37 ° C. The amount of reduction was defined as the number of viable cells.

A petri dish without silk powder was used as a control (100%), and the cell growth number of the petri dish with silk powder was measured. The results are shown in Table 1.

As a result, the silk powder has cell viability in the untreated state (1), but the cell viability decreases as the temperature of the dry heat treatment increases, and at 200 ° C., the cell viability almost disappears. At 210 ° C, cell viability is rather inhibited.

Table 1 shows the relationship between the dry heat treatment temperature of silk powder and the cell growth rate.

Table 1 Dry heat treatment of silk powder and cell growth rate Control (control) 100%

(1) Room temperature 183%

(2) 180. C 152%

(3) 190. C 138%

(4) 200 ° C 101%

(5) 210 ° C 45% [Example 3]

(Spinning of double-layered fiber)

First, the silk powder (B) of Example 1 was put into a PE together with a plasticizer, and the mixture was applied to the silk powder and PE at 145 ° C and 25 minutes using Laboplastomil [Toyo Seiki Seisakusho]. Was kneaded and kneaded to produce spinning chips.

The weight ratio of silk powder to PE in this chip is 2 to 8. Next, unstretched yarn was prepared by spinning such that PP became the core and PE containing the silk powder became the sheath.

At this time, it was made to pass the maximum temperature of 180 ° C in 5 minutes in the Laboplasto mill.

The undrawn yarn is drawn at room temperature to about 4 times the length (drawn yarn, see Fig. 1)

) o

Images were taken under a polarizing microscope so that the silk powder particles in the drawn yarn could be confirmed.

In the drawn yarn, the portion that appears to be small and shiny is the silk powder, and it can be seen that the silk powder is localized near the fiber surface (see Fig. 2).

) o

The tensile strength of the drawn fiber (FIG. 2) was about 11.5 that of the PE / PP double-layered fiber when the silk powder was not mixed.

Silk powder is often buried in the unstretched sheath.

The undrawn yarn becomes thinner by drawing (the thickness of the sheath becomes thinner), but since the silk powder is not drawn, the silk powder buried in the sheath resin is retained on the resin and remains on the fiber surface. Appear.

At this time, the resin of the sheath is partially divided by the silk powder in the fiber axis direction (arrow in FIG. 1), and in this case, the fiber itself has a unique touch. Some powders appear on the fiber surface.

FIG. 1 shows a micrograph of a double-layered fiber containing silk powder in a sheath.

FIG. 2 is a polarizing microscope photograph.

(Example 4)

(Evaluation of synthetic fibers containing silk powder)

A questionnaire survey was conducted on the texture, feel, etc., of the PP / PE core-sheath fiber (A) containing the silk powder in the PE sheath obtained in Example 3.

The core-sheath fiber (B) of PPZPE without silk powder was used as a control for comparison.

In each case, the filament is clamped with a crimper, cut into a length of 51 mm, and a cotton-like fiber of 10 g each.

A is 6.6 d (tex), B is 6.3 d (tex)

).

The questionnaire was for 13 women in their 20s, 2 men, 3 women in their 30s, 2 men, 3 men in their 40s, 2 women in their 50s, and 2 men. I asked her name and asked her to choose between A and B.

The results are shown in Table 2.

Hydrophobic polymers, such as PE and PP, have no hygroscopic properties, so they are slicked, but the moisture-absorbing silk powder in them gives a slimy feel ^)

In addition, it was felt that the touch was excellent due to the biocompatibility of the silk, and the overall result was excellent in luxury.

Questionnaire evaluation of synthetic fibers containing silk powder

Interview items Texture Softness and slickness Skin feel Luxury

A 2 2 8 2 4 2 5 2 3

Number of people who chose B fiber 4 1 8 2 1 3

C Example 5]

[Spinning of single-layer structural fibers]

First, the silk powder (B) of Example 1 was put into PE together with a plasticizer, and kneaded with a laboplast mill (Toyo Seiki Seisakusho) at 145 ° C for 25 minutes. The yarn was kneaded to make a chip for spinning.

The weight ratio of silk powder to PE in this chip is 1.5 to 8.5.

Next, this chip was spun (undrawn yarn).

At this time, it was made to pass through the maximum temperature of 170 ° C in the laboratory plastic mill in 6 minutes.

When the undrawn yarn was drawn at room temperature, it became about 4 times as long.

When the silk powder particles of the drawn yarn were observed under a polarizing microscope, the silk powder appeared to be dispersed throughout the fiber, and many particles appeared on the fiber surface.

[Comparative Example 1]

Spinning of silk powder containing particles with particle size of 10 // D1 or more

Using the method described in Japanese Patent Application Laid-Open No. 2001-48989 (a method for producing ultrafine crystalline silk powder), a silk powder was produced as follows.

The raw silk of silkworm is boiled with a 50% volume of 0.1% aqueous sodium carbonate solution for one hour and scoured to make fibroin fiber (silk thread). Then, 8 g of sodium carbonate was added, and the mixture was boiled at normal pressure for 5 hours, washed with water and dried.

Next, the silk material is ground with a stirring and crushing device (Ishikawa type), and then crushed with a rotary impact crusher [Sample Mill KI-1 manufactured by Fuji Electric Industries Co., Ltd.]. The mixture was pulverized with a pulverizer (current jet CJ-10 manufactured by Nisshin Flour Milling Co., Ltd.).

The particle size of the obtained silk powder is 0! ~ 1 2. The average particle size was 5.3 m.

In this case, no crushing or classification was performed.

Using this powder, spinning of a two-layer structure fiber was attempted in the same manner as in [Example 3], but could not be spun.

First, in the spinning of a sheath pellet containing silk powder, the resin as a raw material of the synthetic fiber and the silk powder did not mix well and did not flow smoothly, so that many defective products were produced.

Next, the obtained pellets were used to spin a two-layer structure fiber. However, the spinnability of the pellets was low, and thus the fibers could not be spun into fibers. Industrial applicability

The present invention relates to a synthetic fiber produced from a thermoplastic synthetic polymer containing silk powder, and particularly relates to a synthetic fiber excellent in biocompatibility and also excellent in durability and moldability. As long as the principle is not deviated, it can be applied to clothing, medical materials, etc., and similar effects can be expected.

Claims

The scope of the claims

1. The core material is made of a thermoplastic synthetic polymer, and the sheath material is a silk powder substantially free from powder particles having a particle diameter of more than 10 m and a melting point of 20%.

A biocompatible core-sheath composite fiber comprising a thermoplastic synthetic polymer having a temperature of 0 ° C or lower.

2. The biocompatible core sheath according to claim 1, wherein the content of the silk powder in the sheath material is 5 to 50% by weight of the total amount of the silk powder and the thermoplastic synthetic polymer. Type composite fiber.

3. The biocompatible core according to claim 1, wherein the content of the silk powder in the sheath material is 10 to 30% by weight of the total amount of the silk powder and the thermoplastic synthetic polymer. Sheath type composite fiber.

4. The biocompatible core according to claim 1, wherein the thermoplastic synthetic polymer constituting the core material and the thermoplastic synthetic polymer constituting the sheath material are the same thermoplastic synthetic polymer. Sheath type composite fiber.

5. The biocompatible core / sheath according to claim 1, wherein the thermoplastic synthetic polymer constituting the core material and the thermoplastic synthetic polymer constituting the sheath material are different thermoplastic synthetic polymers. Type composite fiber.

6. A biocompatible synthetic fiber comprising silk powder substantially free from powder particles having a particle size exceeding 10 m and a thermoplastic synthetic polymer having a melting point of 200 ° C or less.

7. The biocompatible synthetic fiber according to claim 6, wherein the content of the silk powder is 5 to 50% by weight of the total amount of the silk powder and the thermoplastic synthetic polymer.

8. The raw material according to claim 6, wherein the content of the silk powder is 10 to 30% by weight of the total amount of the silk powder and the thermoplastic synthetic polymer. Biocompatible synthetic fibers.

9. The biocompatible core-sheath composite fiber or the biocompatible synthetic fiber according to claim 1 or 6, wherein the thermoplastic synthetic polymer is an olefin polymer.

10. The biocompatible core-sheath type composite fiber or the biocompatible synthetic fiber according to claim 9, wherein the olefin-based polymer is polyethylene, polypropylene or a copolymer based on these.

11. The biocompatible core-sheath composite fiber according to claim 1 or 6, characterized in that the fiber has a diameter of 5 to 100 m, preferably 10 to 3 O ^ m. Biocompatible synthetic fibers.

12. Core-sheath composite spinning of core material made of thermoplastic synthetic polymer and sheath material made of silk powder and thermoplastic synthetic polymer, and stretching, characterized in that Fiber manufacturing method.

13. A core material composed of a thermoplastic synthetic polymer, a silk powder substantially free from powder particles having a particle diameter exceeding 10 m, and a thermoplastic synthetic polymer having a melting point of 200 ° C or lower. A method for producing a biocompatible core-in-sheath type composite fiber, comprising subjecting a sheath material to a core-in-sheath composite spinning and stretching.

14. Mix silk powder substantially free from powder particles having a particle size exceeding 10 m and a thermoplastic synthetic polymer having a melting point of 200 ° C or less, heat, knead, and then spun. And a method for producing a biocompatible synthetic fiber.

15. Mixing silk powder and thermoplastic synthetic polymer, heating, kneading, and then melt-spinning, the process of melting and extruding from a spinneret at a temperature of 200 ° C or less, 6 minutes or less The method for producing a biocompatible core-in-sheath type composite fiber or a biocompatible synthetic fiber according to claim 14, wherein the method is carried out for a period of time.