CN111542654A

CN111542654A - Antibacterial fiber and method for producing antibacterial fiber

Info

Publication number: CN111542654A
Application number: CN201980002401.1A
Authority: CN
Inventors: 斋藤宏治; 佐藤裕介
Original assignee: Koa Glass Co Ltd
Current assignee: Koa Glass Co Ltd
Priority date: 2018-12-04
Filing date: 2019-06-03
Publication date: 2020-08-14
Also published as: JPWO2020115928A1; KR20200070157A; TWI708750B; KR102243796B1; WO2020115928A1; EP3683341A1; US20210332502A1; EP3683341A4; TW202021924A; JP6707725B1

Abstract

The present invention provides an antimicrobial fiber capable of exhibiting excellent antimicrobial properties by reducing the amount of antimicrobial glass in the core part to less than the amount of antimicrobial glass in the sheath part, and an effective method for producing such an antimicrobial fiber. The antimicrobial fiber comprises a thermoplastic resin and an antimicrobial glass as compounding ingredients, and has an average diameter of the antimicrobial fiber within a range of 1 to 50 [ mu ] m, and the antimicrobial fiber is provided with a core part and a sheath part, wherein when the content of the antimicrobial glass in the core part is Q1 (wt%) relative to the total amount of the antimicrobial fiber, and the content of the antimicrobial glass in the sheath part is Q2 (wt%) relative to the total amount of the antimicrobial fiber, Q1 and Q2 satisfy the following relational expression (1). Q1 < Q2 (1).

Description

Antibacterial fiber and method for producing antibacterial fiber

Technical Field

The present invention relates to an antibacterial fiber and a method for producing an antibacterial fiber.

In particular, the present invention relates to an antimicrobial fiber having a core part and a sheath part, in which the content of the antimicrobial glass in the core part is less than the content of the antimicrobial glass in the sheath part, and which can exhibit excellent antimicrobial properties even when the amount of the antimicrobial glass to be added is small, and a method for producing the antimicrobial fiber.

Background

Conventionally, antibacterial fiber products obtained by antibacterial processing of fiber products have been widely used. As a method for producing such an antibacterial fiber, there are: a method of immobilizing an antibacterial glass composition (glass particles) on the surface of a fiber matrix of synthetic fibers or natural fibers, and a method of dispersing an antibacterial glass composition in a fiber matrix (patent document 1).

As a method for fixing glass particles to the surface of a fiber matrix, an antibacterial fiber obtained by (a) fixing glass particles in an adhesive form via an adhesive polymer layer formed on the surface of a fiber matrix, (b) further covering the surface side of the fixed glass particles with a coating layer made of a polymer or the like, (c) covering the surface of the glass particles with a fixing resin layer in advance, softening the fixing resin layer by heating to adhere to the surface of the fiber matrix, and then curing the resin layer to fix composite particles is disclosed.

Further, as a method for dispersing glass particles in a fiber matrix, the following are disclosed: glass particles are blended in a spinning solution that can be a fiber matrix in advance, and the resulting mixture is spun to obtain an antibacterial fiber in a dispersed form.

On the other hand, patent document 2 discloses the following antibacterial polyester fibers: a core-sheath composite fiber having an antibacterial agent in the core, wherein the proportion of the sheath after alkali weight reduction processing is 2 to 20 wt% relative to the weight of the fiber, the content of the antibacterial agent in the core is 0.1 to 10 wt% relative to the weight of the fiber, and the color difference (Delta E) before and after alkali weight reduction processing is less than 2.0.

Documents of the prior art

Patent document

Patent document 1: japanese patent laid-open publication No. 2001-247333

Patent document 2: japanese laid-open patent publication No. 11-158730

Disclosure of Invention

However, the antibacterial fiber obtained by the method of fixing glass particles to the surface of a fiber matrix disclosed in patent document 1 is fixed with a binder or covered with a coating layer in order to fix the glass particles to the fiber surface. Therefore, there are problems as follows: in order to fix the glass particles, it is not only troublesome but also difficult to obtain sufficient antibacterial properties, and further, the cost is high, which is economically disadvantageous.

In addition, in the antibacterial fiber obtained by the method of dispersing the antibacterial glass particles in the fiber matrix disclosed in patent document 1, only the antibacterial glass particles fixed to the surface of the fiber exhibit the antibacterial effect, and the center portion of the fiber also contains the glass particles. Therefore, there are problems as follows: it is necessary to add a large amount of antimicrobial glass particles containing expensive silver or the like.

On the other hand, the antibacterial fiber disclosed in patent document 2 contains an antibacterial agent only in the core portion in order to prevent oxidation and discoloration (coloration) of silver as an antibacterial component due to alkali weight reduction processing, and as a result, antibacterial properties are reduced. Therefore, there is a problem that a sufficient antibacterial effect cannot be obtained because the antibacterial agent is not present on the fiber surface.

As a result of intensive studies, the inventors of the present invention have found that the antibacterial fibers exhibit excellent antibacterial properties even when the amount of the antibacterial glass to be blended is small, and have completed the present invention. The antimicrobial fiber comprises a thermoplastic resin and an antimicrobial glass as compounding ingredients, and has an average diameter of the antimicrobial fiber within a range of 1 to 50 [ mu ] m, and the antimicrobial fiber is provided with a core part and a sheath part, wherein when the content of the antimicrobial glass in the core part is Q1 (wt%) relative to the total amount of the antimicrobial fiber, and the content of the antimicrobial glass in the sheath part is Q2 (wt%) relative to the total amount of the antimicrobial fiber, Q1 and Q2 satisfy a predetermined relational expression.

That is, an object of the present invention is to provide: an antimicrobial fiber capable of exhibiting excellent antimicrobial properties by reducing the amount of antimicrobial glass in the core part to less than the amount of antimicrobial glass in the sheath part and thereby allowing the antimicrobial glass to be incorporated in a small amount, and an effective method for producing such an antimicrobial fiber.

According to the present invention, an antibacterial fiber capable of solving the above-mentioned problems is provided. The antimicrobial fiber is characterized by comprising a thermoplastic resin and an antimicrobial glass as compounding ingredients, wherein the average diameter of the antimicrobial fiber is set to a value within the range of 1 to 50 [ mu ] m, the antimicrobial fiber is provided with a core part and a sheath part, and when the content of the antimicrobial glass in the core part is Q1 (wt%) relative to the total amount of the antimicrobial fiber and the content of the antimicrobial glass in the sheath part is Q2 (wt%) relative to the total amount of the antimicrobial fiber, Q1 and Q2 satisfy the following relational expression (1),

Q1＜Q2 (1)

that is, the content of the antimicrobial glass in the core portion can be adjusted to be smaller than the content of the antimicrobial glass in the sheath portion, and even if the amount of the antimicrobial glass added is small relative to the total amount of the antimicrobial fibers, excellent antimicrobial properties can be exhibited for a long period of time from the beginning.

In the case of constituting the antibacterial fiber of the present invention, Q1 is preferably 0 wt%, or less than 1 wt% excluding 0 wt%.

With this configuration, the content of the antimicrobial glass in the core portion which is difficult to contribute to the antimicrobial effect can be reduced.

In the antibacterial fiber of the present invention, Q2 is preferably set to a value in the range of 1 to 10% by weight.

With this configuration, the antimicrobial glass can be blended in a more preferable range with respect to the total amount of the antimicrobial fibers.

In the case of constituting the antibacterial fiber of the present invention, it is preferable to further contain aggregated silica particles as a compounding ingredient.

With this configuration, since the silica particles rich in hydrophilicity are attached to the periphery of the antimicrobial glass, the dissolution rate of the antimicrobial glass becomes uniform, and the antimicrobial fiber is excellent in coloring property.

In the case of forming the antibacterial fiber of the present invention, the volume average particle diameter of the antibacterial glass is preferably in the range of 0.1 to 5 μm.

With this configuration, the antimicrobial glass can be dispersed more uniformly in the resin component, and the antimicrobial glass can be stably processed into antimicrobial fibers.

In the antibacterial fiber of the present invention, the thermoplastic resin is preferably at least one of a polyester resin, a polyamide resin and a polyolefin resin.

With this configuration, the antimicrobial glass can be more uniformly dispersed in the resin component, and therefore, an excellent antimicrobial effect can be obtained.

In the case of constituting the antibacterial fiber of the present invention, the form of the antibacterial fiber is preferably any of a woven fabric, a nonwoven fabric and a felt.

That is, since the antibacterial fiber of the present invention has a predetermined shape, a textile, a nonwoven fabric, and a felt which exhibit excellent antibacterial properties can be obtained even if the amount of the antibacterial glass to be blended is reduced.

Another aspect of the present invention is a method for producing an antimicrobial fiber, the antimicrobial fiber including a core portion and a sheath portion and containing a thermoplastic resin and an antimicrobial glass as compounding components, the method including the following steps (1) to (3).

Step (1): an antimicrobial glass is prepared by preparing a glass for antimicrobial,

step (2): when the content of the antimicrobial glass in the core part is Q1 (wt%) relative to the total amount of the antimicrobial fibers and the content of the antimicrobial glass in the sheath part is Q2 (wt%) relative to the total amount of the antimicrobial fibers, the obtained antimicrobial glass is dispersed in a thermoplastic resin so that Q1 and Q2 satisfy the following relational expression (1) to prepare a spinning dope for the core part and a spinning dope for the sheath part,

Q1＜Q2 (1)

step (3): using a core-sheath composite spinning die head to perform composite spinning by using a spinning solution for a core part as a core part and a spinning solution for a sheath part as a sheath part to prepare an antibacterial fiber with an average diameter of 1-50 μm,

that is, by including the steps (1) to (3), the content of the antimicrobial glass in the core portion can be made smaller than the content of the antimicrobial glass in the sheath portion.

Therefore, the amount of the antimicrobial glass to be added may be small relative to the total amount of the antimicrobial fibers, and excellent antimicrobial properties can be exhibited.

Drawings

Fig. 1 is an electron micrograph (SEM image, magnification 2000) of the antibacterial fiber of the present embodiment.

Fig. 2 is a schematic view of the antibacterial fiber having a core portion and a sheath portion according to the present embodiment.

Fig. 3 is an electron micrograph (SEM image, magnification 2000) of the antibacterial fiber of example 1.

Fig. 4 (a) to (c) show EDX surface scan analysis results of the antibacterial fiber of example 1.

Fig. 5 (a) to (c) show EDX surface scan analysis results of the antibacterial fiber of example 2.

Detailed Description

[ embodiment 1]

Embodiment 1 is an antimicrobial fiber comprising a thermoplastic resin and an antimicrobial glass as compounding ingredients, wherein the average diameter of the antimicrobial fiber is set to a value within the range of 1 to 50 μm, wherein the antimicrobial fiber comprises a core part and a sheath part, and wherein Q1 and Q2 satisfy the following relational expression (1) when the content of the antimicrobial glass in the core part is Q1 (wt%) relative to the total amount of the antimicrobial fiber and the content of the antimicrobial glass in the sheath part is Q2 (wt%) relative to the total amount of the antimicrobial fiber.

Q1＜Q2 (1)

Hereinafter, each constituent element of the antibacterial fiber according to embodiment 1 will be specifically described.

1. Thermoplastic resin

(1) Principal component

(1) -1 kinds of

As a main component of the resin constituting the antibacterial fiber of the present embodiment, a thermoplastic resin is used.

The kind of such thermoplastic resin is not particularly limited, and is preferably at least one of a polyester resin, a polyamide resin, a polyurethane resin, a polyolefin resin (including a polyacrylic resin), a rayon-based resin, a polyvinyl acetate-based resin, a cellulose-based resin, a polyvinyl chloride-based resin, and a polyacetal resin.

The reason for this is that: if the polyester resin is used, an antibacterial fiber having high mechanical strength, durability, and heat resistance and excellent flexibility and processability can be obtained relatively inexpensively.

In addition, the reason is that: if the polyamide resin is used, an antibacterial fiber having high mechanical strength, durability and heat resistance and moisture absorption can be obtained relatively inexpensively.

In addition, the reason is that: the polyurethane resin can provide an antibacterial fiber having high durability and excellent stretchability.

Furthermore, the reason is that: if the resin is a polyolefin resin (including polyacrylic resin), an antibacterial fiber having excellent transparency and processability can be obtained at low cost.

Among these thermoplastic resins, polyester resins or polyolefin resins are more preferable.

That is, preferred polyester resins include at least one of polyethylene terephthalate resin, polypropylene terephthalate resin, polybutylene terephthalate resin, polycyclohexanedimethanol terephthalate resin, polylactic acid resin, polybutylene succinate resin, polyglycolic acid resin, and the like, and among them, polyethylene terephthalate resin is preferred.

Further, preferable examples of the polyolefin resin include at least one of a polypropylene resin, a polyethylene resin (high-density polyethylene resin, linear polyethylene resin, low-density polyethylene resin, and the like), a polymethylpentene resin, a vinyl acetate copolymer resin, a propylene copolymer resin, and the like, and among them, a polypropylene resin is preferable.

That is, the reason why the polyethylene terephthalate resin is preferable is that: since the thermoplastic resin composition has low heat resistance as compared with a polybutylene terephthalate resin or the like, the thermoplastic resin composition can be stably processed into an antibacterial fiber, an antibacterial film or the like which requires excellent flexibility.

More specifically, the reason is that: the polyethylene terephthalate resin has a smaller crystallization rate than polybutylene terephthalate resin, and is characterized in that crystallization does not proceed unless the temperature is high, and the strength is improved by heat treatment and stretching treatment.

Further, the polyethylene terephthalate resin is economically advantageous because it has high transparency, excellent heat resistance and practical strength, and excellent recyclability.

More specifically, for example, plastic articles composed of polyethylene terephthalate resin such as PET bottles are currently in large circulation and are very inexpensive compared to other resin materials.

Further, if the polyethylene terephthalate resin is used, the resin is actively recycled, and the following current situation shows that: this makes the polyethylene terephthalate resin a cheaper resin material because it is easily reused as compared with other resin materials.

The polyethylene terephthalate resin may also be a copolyester containing other copolymerization components.

In addition, if the polypropylene resin is used, the mechanical strength such as tensile strength, impact strength and compressive strength is excellent, and can be adjusted according to the application.

Further, it is considered that the fiber is excellent not only in abrasion resistance and chemical resistance but also in quick-drying properties and heat retention properties, and therefore can be preferably used for antibacterial fibers.

Therefore, by using a polyethylene terephthalate resin or a polypropylene resin as a main component, crystallization of the thermoplastic resin composition during the production and molding of the antibacterial fiber can be effectively suppressed, and the antibacterial fiber, the antibacterial film, or the like can be stably processed.

(1) -2 number average molecular weight

If the thermoplastic resin as the main component is polyethylene terephthalate resin, polypropylene resin, or the like, it is preferable that the number average molecular weight thereof is in the range of 5000 to 80000.

The reason for this is that: when the number average molecular weight of the polyethylene terephthalate resin, the polypropylene resin, or the like is in the above range, the compatibility with a resin which is a subcomponent of a thermoplastic resin described later can be improved, and hydrolysis of the resin can be effectively suppressed, so that the antimicrobial glass can be dispersed more uniformly.

Therefore, the number average molecular weight of the thermoplastic resin is more preferably set to a value within a range of 10000 to 60000, and still more preferably to a value within a range of 20000 to 50000.

(1) -3 melting Point

The melting point of the thermoplastic resin as the main component is preferably set to a value within the range of 150 to 350 ℃.

The reason for this is that: when the melting point is 150 ℃ or higher, the mechanical properties such as tensile strength and tear strength of the thermoplastic resin composition can be sufficiently ensured, and the viscosity is appropriate when the composition is heated and melted, so that appropriate processability can be obtained.

On the other hand, the reason is that: when the melting point is 350 ℃ or lower, the thermoplastic resin composition has good moldability and can be easily mixed with resin components other than the thermoplastic resin described later.

Therefore, the melting point of the thermoplastic resin as the main component is more preferably set to a value within the range of 200 to 300 ℃, and still more preferably 230 to 270 ℃.

The melting point of the resin can be measured according to ISO 3146.

When the melting point is not observed, the glass transition temperature is preferably set to a value in the range of 150 to 350 ℃.

(1) -4 compounding amount

The amount of the polyethylene terephthalate resin or the polypropylene resin is preferably 80 to 99.4 parts by weight based on 100 parts by weight of the total amount of the thermoplastic resin composition.

The reason for this is that: when the amount of the polyethylene terephthalate resin or the polypropylene resin is in the above range, the hydrolysis of the resin can be effectively suppressed, and the thermoplastic resin composition can be easily processed into an antibacterial fiber or an antibacterial film.

Therefore, the amount of the polyethylene terephthalate resin or the polypropylene resin is preferably 85 to 99 parts by weight, more preferably 90 to 98 parts by weight, based on 100 parts by weight of the total amount of the antibacterial resin composition.

(1) -5 tensile Strength

The tensile strength of the resin as the main component is preferably in the range of 20 to 100MPa as measured according to JIS L1015.

The reason for this is that: if the tensile strength of the resin is less than 20MPa, the fibers may be broken during stretching, or the product using the antibacterial fibers may be torn during washing or the like.

On the other hand, the reason is that: if the tensile strength of the resin exceeds 100MPa, the flexibility as the antibacterial fiber is insufficient, and the use thereof may be limited too much.

Therefore, the tensile strength of the resin is more preferably set to a value within a range of 25 to 95MPa, and still more preferably to a value within a range of 30 to 90 MPa.

(2) Mixed resin

(2) -1 kinds of

When the thermoplastic resin in the present embodiment contains a polyethylene terephthalate resin as a main component, a mixed resin containing a polybutylene terephthalate resin as another resin component is preferable.

The reason for this is that: by containing a polybutylene terephthalate resin which is more excellent in hydrolysis resistance than a polyethylene terephthalate resin, hydrolysis of the polyethylene terephthalate resin due to moisture contained in the antimicrobial glass can be effectively suppressed at the time of heating and melting of the thermoplastic resin in the production and molding of the antimicrobial fiber.

More specifically, it is believed that: the polybutylene terephthalate resin has higher lipophilicity than the polyethylene terephthalate resin, and contains a smaller number of ester bonds per unit weight, and is therefore less likely to undergo hydrolysis.

Therefore, by containing the polybutylene terephthalate resin, hydrolysis of the polyethylene terephthalate resin as the main component can be effectively suppressed, and an inexpensive thermoplastic resin having excellent dispersibility of the antimicrobial glass can be obtained.

That is, by mixing a predetermined amount of the antimicrobial glass with the polybutylene terephthalate resin in advance to prepare a master batch containing the antimicrobial glass at a high concentration, and then mixing the polyethylene terephthalate resin, hydrolysis of the polyethylene terephthalate resin can be suppressed, and finally an antimicrobial resin composition having a predetermined mixing ratio can be obtained.

The polybutylene terephthalate resin in the present embodiment is a polymer obtained by basically performing a polycondensation reaction of terephthalic acid or an ester-forming derivative thereof as an acid component and 1, 4-butanediol or an ester-forming derivative thereof as a diol component.

Incidentally, if the total amount of the acid components is 100 mol%, other acid components may be contained if the amount is in the range of 20 mol% or less.

(2) -3 compounding amount

The amount of the polybutylene terephthalate resin is preferably in the range of 0.5 to 25 parts by weight per 100 parts by weight of the polyethylene terephthalate resin.

The reason for this is that: when the amount of the polybutylene terephthalate resin is in the above range, a thermoplastic resin can be obtained which contains, as a main component, a polyethylene terephthalate resin that can be processed into an antibacterial fiber or an antibacterial film and which has hydrolysis resistance and further has excellent dispersibility of antibacterial glass.

Therefore, more specifically, the amount of the polybutylene terephthalate resin is preferably in the range of 2 to 15 parts by weight, and more preferably 3 to 10 parts by weight, based on 100 parts by weight of the polyethylene terephthalate resin.

(3) Different resin composition

In the present invention, the types of thermoplastic resins used for the core portion and the sheath portion may be the same or different. If the types of thermoplastic resins used in the core section and the sheath section are the same, the affinity between the core section and the sheath section is good, and the antibacterial fiber can be stably obtained.

On the other hand, when the types of thermoplastic resins used for the core portion and the sheath portion are different, the mechanical properties such as tensile strength and tear strength of the obtained antimicrobial fiber can be enhanced by using a resin having higher mechanical strength for the core portion.

2. Antibacterial glass

The antibacterial fiber of the present embodiment contains an antibacterial glass, and the antibacterial glass preferably contains silver ions as an antibacterial active ingredient.

The reason for this is that: such an antimicrobial glass has high safety, long duration of antimicrobial action, and high heat resistance, and therefore has excellent suitability as an antimicrobial agent contained in an antimicrobial fiber.

(1) Composition of

Further, it is preferable that the antimicrobial glass is one of a phosphoric acid-based antimicrobial glass and a borosilicate-based glass or both of them.

The reason for this is that: in the case of phosphoric acid-based antimicrobial glass or borosilicate-based glass, since the antimicrobial active ingredient is released while absorbing water and dissolving, the discoloration of the thermoplastic resin can be prevented, and the amount of the antimicrobial active ingredient such as silver ions in the antimicrobial fiber can be adjusted to an appropriate range.

(1) -1 glass composition 1

In addition, as the glass composition of the phosphoric acid-based antibacterial glass, Ag is contained₂O、ZnO、CaO、B₂O₃And P₂O₅And Ag is preferably used when the total amount is 100 wt%₂The amount of O is 0.2-5 wt%, the amount of ZnO is 2-60 wt%, the amount of CaO is 0.1-15 wt%, and B₂O₃The amount of (b) is in the range of 0.1 to 15 wt%, and P is added₂O₅The amount of (A) is in the range of 30 to 80 wt%, and the weight ratio of ZnO/CaO is in the range of 1.1 to 15.

Here, Ag₂O is an essential component of the antibacterial ion-releasing substance in the glass composition 1, and the Ag is contained₂O can slowly elute silver ions at a predetermined rate when the glass component is dissolved, and can exhibit excellent antibacterial properties for a long period of time.

In addition, Ag is preferably used₂The amount of O is 0.2 to 5 wt%.

The reason for this is that: if Ag₂When the amount of O is 0.2 wt% or more, sufficient antibacterial properties can be exhibited.

On the other hand, the reason is that: if Ag₂When the amount of O is 5 wt% or less, the antimicrobial glass is less likely to be discolored and the cost can be reduced, which is economically advantageous.

Thus, Ag₂The amount of O incorporated is more preferably in the range of 0.5 to 4% by weight, and still more preferably in the range of 0.8 to 3.5% by weight.

In addition, P₂O₅The essential constituent components in the glass composition 1 basically exhibit the function of forming oxides as networks, and in the present invention, the transparency improving function of the antimicrobial glass and the uniform release property of silver ions are involved.

As P₂O₅The amount of (b) is preferably in the range of 30 to 80% by weight.

The reason for this is that: if the above-mentioned P is₂O₅When the amount of (b) is 30% by weight or more, the transparency of the antimicrobial glass is not easily lowered, and uniform release of silver ions and physical strength are easily ensured.

On the other hand, the reason is that: if the above-mentioned P is₂O₅When the amount of (b) is 80% by weight or less, the antimicrobial glass is not easily yellowed and the curability is good, so that the physical strength can be easily secured.

Thus, P₂O₅The amount of (b) is more preferably within a range of 35 to 75% by weight, and still more preferably within a range of 40 to 70% by weight.

In addition, ZnO is an essential constituent component in the glass composition 1, and has a function as a network-modifying oxide in the antimicrobial glass, and also has functions of preventing yellowing and improving antimicrobial properties.

The amount of ZnO to be added is preferably in the range of 2 to 60 wt% based on the total amount.

The reason for this is that: if the amount of ZnO is 2 wt% or more, the yellowing prevention effect and the antibacterial property are easily improved, but the reason is that: if the amount of ZnO is 60 wt% or less, the transparency of the antimicrobial glass is not easily lowered, and the mechanical strength is easily secured.

Therefore, the amount of ZnO is more preferably 5 to 50 wt%, and still more preferably 10 to 40 wt%.

The amount of ZnO is preferably determined in consideration of the amount of CaO to be described later.

Specifically, the weight ratio expressed by ZnO/CaO is preferably in the range of 1.1 to 15.

The reason for this is that: if the weight ratio is a value of 1.1 or more, yellowing of the antimicrobial glass can be effectively prevented, on the other hand, the reason is that: if the weight ratio is 15 or less, the antimicrobial glass is less likely to be clouded or yellowed.

Therefore, the weight ratio expressed by ZnO/CaO is more preferably in the range of 2.0 to 12, and still more preferably in the range of 3.0 to 10.

CaO is an essential constituent component in the glass composition 1, and has a function of basically functioning as a network-modifying oxide, and also a function of reducing the heating temperature at the time of producing an antibacterial glass, and preventing yellowing together with ZnO.

The amount of CaO blended is preferably in the range of 0.1 to 15 wt% based on the total amount.

The reason for this is that: if the amount of CaO added is 0.1% by weight or more, the yellowing prevention function and the melting temperature lowering effect are easily exhibited, but the reason is that: if the amount of CaO added is 15 wt% or less, the deterioration of the transparency of the antimicrobial glass is easily suppressed.

Therefore, the amount of CaO blended is preferably within a range of 1.0 to 12 wt%, and more preferably within a range of 3.0 to 10 wt%.

In addition, B₂O₃The essential constituent components in the glass composition 1 basically exhibit the function of forming oxides as networks, and in the present invention, the essential constituent components are components relating to the transparency improving function of the antimicrobial glass and the uniform release property of silver ions.

As B₂O₃The amount of (b) is preferably in the range of 0.1 to 15 wt% based on the total amount.

The reason for this is that: if said B is₂O₃When the amount of (b) is 0.1% by weight or more, the transparency of the antimicrobial glass can be sufficiently ensured, and the uniform release property of silver ions and the mechanical strength can be easily ensured.

On the other hand, the reason is that: if said B is₂O₃When the amount of (b) is 15% by weight or less, yellowing of the antimicrobial glass is easily suppressed, and the curability is improved, and the mechanical strength is easily ensured.

Thus, as B₂O₃The amount of (b) is preferably in the range of 1.0 to 12 wt%The value within the range is more preferably 3.0 to 10% by weight.

It should be noted that, as optional constituent components of the glass composition 1, it is also preferable to add a predetermined amount of CeO within the target range of the present invention₂、MgO、Na₂O、Al₂O₃、K₂O、SiO₂BaO, etc.

(1) -2 glass composition 2

In addition, as the glass composition of the phosphoric acid-based antibacterial glass, Ag is contained₂O、CaO、B₂O₃And P₂O₅Instead of substantially not containing ZnO, Ag is preferably used when the total amount is 100 wt%₂The amount of O is 0.2-5 wt%, the amount of CaO is 15-50 wt%, and B₂O₃The amount of (b) is in the range of 0.1 to 15 wt%, and P is added₂O₅The amount of CaO/Ag is in the range of 30-80 wt%₂The weight ratio of O is in the range of 5-15.

Here, with respect to Ag₂O may be the same as in the glass composition 1.

Therefore, Ag is preferably used₂The amount of O is in the range of 0.2 to 5 wt%, more preferably in the range of 0.5 to 4.0 wt%, and still more preferably in the range of 0.8 to 3.5 wt% based on the total amount.

Further, by using CaO in the antimicrobial glass, the antimicrobial glass can basically exhibit a function as a network-modifying oxide, and can lower the heating temperature at the time of producing the antimicrobial glass to exhibit a yellowing prevention function.

That is, the amount of CaO blended is preferably set to a value within a range of 15 to 50 wt% of the total amount.

The reason for this is that: if the amount of CaO is 15 wt% or more, the yellowing prevention function and the melting temperature lowering effect are exhibited even if ZnO is not substantially contained, but the reason is that: when the amount of CaO added is 50% by weight or less, the transparency of the antimicrobial glass can be sufficiently ensured.

Therefore, the amount of CaO blended is more preferably within a range of 20 to 45 wt%, and still more preferably within a range of 25 to 40 wt%.

It is preferable to consider Ag as the amount of CaO to be added₂The amount of O is determined, and specifically, CaO/Ag is preferably used₂O is a value in the range of 5 to 15 by weight.

More specifically, CaO/Ag is more preferably used₂The weight ratio represented by O is in the range of 6 to 13, and more preferably in the range of 8 to 11.

In addition, as to B₂O₃And P₂O₅The same contents as those of glass composition 1 may be used.

Further, as in the case of the glass composition 1, it is also preferable to add a predetermined amount of CeO as an optional constituent component within the range of the object of the present invention₂、MgO、Na₂O、Al₂O₃、K₂O、SiO₂BaO, etc.

(1) -3 glass composition 3

Further, the borosilicate glass contains B as a glass composition₂O₃、SiO₂、Ag₂O, alkali metal oxide, and B is preferably used when the total amount is 100% by weight₂O₃The amount of (A) is in the range of 30 to 60 wt%, and SiO is added₂The amount of (A) is in the range of 30 to 60 wt%, and Ag is added₂The amount of O is 0.2-5 wt%, the amount of alkali metal oxide is 5-20 wt%, and Al is₂O₃The amount of (C) is in the range of 0.1 to 2 wt%, and when the total amount is less than 100 wt%, other glass components (alkaline earth metal oxide, CeO) are contained as the remaining components in the range of 0.1 to 33 wt%₂CoO, etc.).

Here, in the compounding composition of the alkali antimicrobial glass, B₂O₃Basically exhibits a function of forming an oxide as a network, a transparency improving function, and a uniform silver ion releasing propertyIt is related.

In addition, SiO₂The antibacterial glass has a function of forming an oxide as a network and a function of preventing yellowing.

In addition, Ag₂O is an essential constituent component in the antimicrobial glass, and dissolution of the glass component causes silver ions to be eluted, thereby enabling the antimicrobial glass to exhibit excellent antimicrobial properties over a long period of time.

Alkali metal oxides, e.g. Na₂O or K₂O basically functions as a network-modified oxide, while it can function to adjust the dissolution characteristics of the antimicrobial glass, thereby lowering the water resistance of the antimicrobial glass and adjusting the amount of silver ion released from the antimicrobial glass.

The alkaline earth metal oxide functions as a network-modifying oxide by adding MgO or CaO, for example, and can also function as an antimicrobial glass to improve transparency and adjust a melting temperature, similarly to the alkali metal oxide.

Further, by adding CeO additionally₂、Al₂O₃And the color change, transparency, or mechanical strength to electron beams can be improved.

(2) Dissolution rate

Further, it is preferable that the elution rate of antibacterial ions from the antibacterial glass is 1 × 10²～1×10⁵A value in the range of mg/Kg/24 Hr.

The reason is that if the elution rate of the antibacterial ion is less than 1 × 10²The reason why the antibacterial activity is remarkably lowered in some cases is that the elution rate of the antibacterial ion exceeds 1 × 10⁵mg/Kg/24Hr may make it difficult to exert antibacterial effect for a long period of time or may reduce the transparency of the antibacterial fiber obtained, and therefore, from the viewpoint of more preferably balancing the antibacterial property and transparency, it is more preferable to set the elution rate of antibacterial ions from the antibacterial glass to 1 × 10³～5×10⁴A value within the range of mg/Kg/24Hr, more preferably 3 × 10³～1×10⁴A value in the range of mg/Kg/24 Hr. It should be noted thatThe elution rate of the antibacterial ion can be measured under the following measurement conditions.

(measurement conditions)

100g of an antimicrobial glass was immersed in 500ml of distilled water (20 ℃ C.) and shaken for 24 hours using a shaker. Subsequently, the Ag ion-dissolved solution was separated by a centrifugal separator, and then filtered by a filter paper (5C) to prepare a measurement sample. Then, Ag ions in the measurement sample were measured by ICP emission spectrometry, and the amount of eluted Ag ions (mg/Kg/24Hr) was calculated.

(3) Volume average particle diameter

The volume average particle diameter (volume average primary particle diameter, D50) of the antimicrobial glass is preferably in the range of 0.1 to 5.0 μm.

The reason for this is that: when the volume average particle diameter of the antimicrobial glass is in the above range, the antimicrobial glass can be dispersed more uniformly, and the thermoplastic resin containing the antimicrobial glass can be processed into an antimicrobial fiber or an antimicrobial film more stably.

Namely, the reason is that: when the volume average particle diameter of the antimicrobial glass is 0.1 μm or more, mixing and dispersion into the resin component are easy, light scattering can be suppressed, or transparency can be easily secured.

On the other hand, the reason is that: when the volume average particle diameter of the antimicrobial glass is 5.0 μm or less, the antimicrobial glass can be uniformly dispersed in the resin component, and the mechanical strength of the antimicrobial fiber can be easily ensured.

Therefore, the volume average particle diameter of the antimicrobial glass is more specifically preferably in the range of 0.5 to 4.0 μm, and still more preferably in the range of 1.0 to 3.0 μm.

The volume average particle diameter (D50) of the antimicrobial glass particles can be calculated from a particle size distribution obtained by using a laser particle counter (according to JIS Z8852-1) or a sedimentation particle size distribution meter, or a particle size distribution obtained by performing image processing based on an electron micrograph of the antimicrobial glass.

(4) Specific surface area

In addition, thePreferably, the specific surface area of the antibacterial glass is 10000 to 300000cm²/cm³A value within the range of (1).

The reason for this is that: if the above specific surface area is 10000cm²/cm³The above value makes it easy to mix, disperse or treat the resin component, and to secure surface smoothness and mechanical strength when the antibacterial fiber is produced.

On the other hand, if the above specific surface area is 300000cm²/cm³Hereinafter, the resin component can be easily mixed and dispersed, light scattering is less likely to occur, and a decrease in transparency can be suppressed.

More specifically, the specific surface area of the antimicrobial glass is more preferably 15000 to 200000cm²/cm³A value within the range of (1), more preferably 18000 to 150000cm²/cm³A value within the range of (1).

The specific surface area (cm) of the antimicrobial glass²/cm³) Can be obtained from the results of particle size distribution measurement, and the volume per unit (cm) can be calculated from the actual measurement data of the particle size distribution by assuming that the antimicrobial glass is spherical³) Surface area (cm)²)。

(5) Shape of

The antimicrobial glass particles are preferably polyhedral in shape, that is, polyhedral in shape composed of a plurality of corners or a plurality of faces, for example, 6 to 20 faces.

The reason for this is that: by making the antimicrobial glass particles polyhedral in shape as described above, unlike antimicrobial glass having a spherical shape or the like, light can easily travel in a certain direction in a plane, and light scattering by the antimicrobial glass can be effectively prevented, so that the transparency of the antimicrobial glass can be improved.

Further, by forming the antimicrobial glass particles into polyhedrons, not only mixing and dispersion into the resin component can be easily performed, but also the following characteristics can be obtained: when antibacterial fibers are produced using a spinning apparatus or the like, the antibacterial glass particles are easily oriented in a certain direction.

Therefore, the antimicrobial glass can be easily uniformly dispersed in the resin component, and scattering of light by the antimicrobial glass in the resin component can be effectively prevented, thereby exhibiting excellent transparency.

Further, if the antimicrobial glass has a polyhedral shape, the external additive described later is likely to adhere to the antimicrobial glass, and the antimicrobial glass is less likely to reagglomerate during production, use, or the like.

(6) Surface treatment

The antimicrobial glass particles are preferably surface-treated with a polyorganosiloxane/silicone resin, a silane coupling agent, a titanate coupling agent, an aluminate coupling agent, or the like.

This enables adjustment of the adhesion strength between the antimicrobial glass particles and the thermoplastic resin.

(7) External additive

Further, it is also preferable to add aggregated silica particles (dry silica, wet silica) to the antibacterial glass particles.

When the aggregated silica particles are used as a main component, one kind or a combination of two or more kinds of titanium oxide, zinc oxide, alumina, zirconia, calcium carbonate, white sand microspheres, quartz particles, glass microspheres, and the like are also preferable.

Among these, aggregated silica particles (dry silica and wet silica) or colloidal silica as an aqueous dispersion thereof are particularly preferable as an external additive because they have a small number-average primary particle diameter and are extremely excellent in dispersibility in an antimicrobial glass.

Namely, the reason is that: since such aggregated silica particles are dispersed while being released from the aggregated state, they adhere to the periphery of the antimicrobial glass, and the antimicrobial glass can be uniformly dispersed even in the resin component. Therefore, the antimicrobial glass can be uniformly dispersed in the antimicrobial fiber without being biased.

Further, the number average secondary particle diameter of the aggregated silica as an external additive is preferably set to a value within a range of 1 to 15 μm.

The reason for this is that: if the number average secondary particle diameter of the external additive is a value of 1 μm or more, the dispersibility of the antimicrobial glass 10 is good, light scattering can be suppressed, and transparency can be secured.

On the other hand, the reason is that: if the number average secondary particle diameter of the external additive is 15 μm or less, mixing, dispersion, or treatment into the resin component is easy, and surface smoothness, transparency, and mechanical strength are easily ensured when the antibacterial fiber or the antibacterial film is produced.

Therefore, the number average secondary particle diameter of the external additive is more preferably set to a value within a range of 5 to 12 μm, and still more preferably to a value within a range of 6 to 10 μm.

The number average secondary particle diameter of the external additive can be measured by using a laser particle counter (according to JISZ 8852-1) or a sedimentation particle size distribution analyzer.

Further, the number average secondary particle diameter of the external additive may be calculated by image processing of an electron micrograph thereof.

When the external additive is substantially agglomerated, the number average primary particle diameter in a loose state is preferably set to a value within a range of 0.005 to 0.5 μm.

The reason for this is that: if the number-average primary particle diameter of the external additive is 0.005 μm or more, the effect of improving the dispersibility of the antimicrobial glass is easily obtained, and the light scattering can be suppressed and the decrease in transparency can be suppressed.

On the other hand, if the number-average primary particle diameter of the external additive is 0.5 μm or less, the effect of improving the dispersibility of the antimicrobial glass is similarly obtained, and when the antimicrobial fiber or the antimicrobial film is produced, the mixing, dispersion or treatment in the resin component is similarly performed, and the surface smoothness, transparency, and mechanical strength can be sufficiently ensured.

Therefore, the number average primary particle diameter of the external additive is more preferably in the range of 0.01 to 0.2. mu.m, and still more preferably in the range of 0.02 to 0.1. mu.m.

The number average secondary particle diameter of the external additive can be measured by the same method as the number average secondary particle diameter.

The amount of the aggregated silica added as an external additive is preferably in the range of 0.1 to 50 parts by weight per 100 parts by weight of the antimicrobial glass.

The reason for this is that: when the amount of the external additive is 0.1 parts by weight or more, the dispersibility of the antimicrobial glass is good.

On the other hand, the reason is that: if the amount of the external additive is 50 parts by weight or less, the external additive can be uniformly mixed with the antimicrobial glass, and the transparency of the resulting antimicrobial resin composition is not easily degraded.

Therefore, the amount of the external additive to be added is more preferably in the range of 0.5 to 30 parts by weight, and still more preferably in the range of 1 to 10 parts by weight, based on 100 parts by weight of the antimicrobial glass.

(8) Water content

When the antimicrobial glass particles contain moisture, the content of the moisture is preferably 1 × 10 parts by weight per 100 parts by weight of the solid content of the antimicrobial glass particles^-4A value in the range of about 5 parts by weight.

The reason for this is that: by setting the water content to a value within the above range, hydrolysis of the thermoplastic resin can be effectively suppressed and the antimicrobial glass particles can be uniformly dispersed even when the step of drying the antimicrobial glass is omitted in the production of the thermoplastic resin composition.

That is, if the above-mentioned moisture content is 1 × 10^-4When the amount is more than the weight, it is not necessary to use excessively large equipment as equipment for drying the antimicrobial glass particles, and the time required for the drying step is not likely to become excessively long, so that the economical efficiency is not significantly impaired.

On the other hand, if the moisture content is 5 parts by weight or less, the hydrolysis of the thermoplastic resin can be stably suppressed.

Therefore, it is more preferable that the moisture content of the antimicrobial glass is 1 × 10 per 100 parts by weight of the solid content of the antimicrobial glass^－3A value in the range of 1 part by weight, more preferably 1 × 10^－2～1×10^－1In the range of wt.%The value is obtained.

The moisture content in the antimicrobial glass can be measured by, for example, a heating reduction method at 105 ℃ using an electronic moisture meter, or by the karl fischer method.

(9) Compounding amount

When the content of the antimicrobial glass in the core part is Q1 (wt%) relative to the total amount of the antimicrobial fibers and the content of the antimicrobial glass in the sheath part is Q2 (wt%), the amount of the antimicrobial glass to be added is preferably 0 wt% or more than 0 wt% and less than 1 wt% of Q1 and is in the range of 1 to 10 wt% of Q2.

The reason for this is that: when the amount of the antimicrobial glass to be blended is within the above range, hydrolysis of the thermoplastic resin can be effectively suppressed, and the antimicrobial glass can be uniformly dispersed in the resin component, thereby obtaining an excellent antimicrobial effect.

In addition, with this configuration, the content of the antimicrobial glass in the core portion can be adjusted to be less than the content of the antimicrobial glass in the sheath portion, and even if the amount of the antimicrobial glass is small relative to the total amount of the antimicrobial fibers, excellent antimicrobial properties can be exhibited.

Namely, the reason is that: if Q1 is 0 wt% or less than 1 wt%, the antimicrobial glass is not excessively contained in the center of the antimicrobial fiber, and the absolute amount is sufficient, so that sufficient antimicrobial properties can be imparted to the antimicrobial fiber.

On the other hand, if Q2 is a value in the range of 1 to 10% by weight, the amount of water contained in the antimicrobial glass increases as the amount of antimicrobial glass added increases, but hydrolysis of the thermoplastic resin can be sufficiently suppressed. In addition, the reason is that: can be easily processed into antibacterial fiber and antibacterial film.

Therefore, more specifically, Q1 is more preferably 0% by weight or less than 0.5% by weight, and Q2 is more preferably a value in the range of 1.5 to 9% by weight. Further, Q1 is more preferably 0% by weight or less than 0.1% by weight, and Q2 is more preferably 2 to 8% by weight.

3. Antibacterial fiber

(1) Form of the composition

As shown in the electron micrograph (SEM image) of fig. 1 and the schematic view of fig. 2, the antibacterial fiber 1 of the present embodiment is characterized in that: the antimicrobial glass comprises a core part 20 and a sheath part 30, wherein the content of the antimicrobial glass 10 in the core part 20 is less than the content of the antimicrobial glass 10 in the sheath part 30.

The average diameter of the antimicrobial fibers is preferably in the range of 1 to 50 μm.

The reason for this is that: if the average diameter of the antimicrobial fiber is 1 μm or more, the mechanical strength of the antimicrobial fiber can be easily ensured, and stable production can be performed.

On the other hand, the reason is that: if the average diameter of the antimicrobial fibers is 50 μm or less, the antimicrobial fibers can be used in a wide range of applications because the flexibility of the antimicrobial fibers can be ensured.

Therefore, the average diameter of the antibacterial fiber is more preferably in the range of 2 to 49 μm, and still more preferably in the range of 3 to 48 μm.

The average diameter of the antibacterial fibers may be measured at several points (for example, 5 points) using an electron microscope, a micrometer, or a caliper, and the average value may be obtained. Further, the equivalent circle diameter may be obtained.

(2) Core part

(2) -1 kinds of thermoplastic resins

As the kind of the thermoplastic resin used in the core portion, the above-described thermoplastic resin can be used. The number average molecular weight and melting point of the thermoplastic resin are also preferably values within the above ranges.

(2) -2 mean diameter

The average diameter Φ of the core of the antibacterial fiber 1 of the present embodiment is preferably set to a value in the range of 0.3 to 40 μm.

The reason for this is that: by setting the average diameter of the core portion to a value within the above range, mechanical properties such as tensile strength and tear strength can be sufficiently ensured.

Therefore, the average diameter of the core is more preferably set to a value within a range of 0.5 to 35 μm, and still more preferably 0.7 to 30 μm.

Note that, as for the average diameter of the core portion, the diameter of several points (for example, 5 points) can be actually measured using an electron microscope or a micrometer, and the average value thereof can be taken.

(3) Sheath part

(3) -1 kinds of thermoplastic resins

As the kind of the thermoplastic resin used in the sheath portion, the above-described thermoplastic resin can be used. The number average molecular weight and melting point of the thermoplastic resin are also preferably values within the above ranges.

(3) -2 thickness of sheath

The thickness t of the sheath portion of the antibacterial fiber 1 of the present embodiment is preferably set to a value in the range of 0.7 to 49.7 μm.

The reason for this is that: by setting the thickness of the sheath portion to a value within the above range, a sufficient antimicrobial property can be maintained for a long period of time from the initial stage.

Therefore, the thickness of the sheath portion is more preferably set to a value within a range of 1 to 45 μm, and still more preferably 5 to 40 μm.

Note that the thickness of the sheath portion may be actually measured at several points t (for example, 5 points) using an electron microscope or a micrometer, and the average value may be obtained.

(4) The relation Q1 < Q2

In the antibacterial fiber of the present embodiment, when the content of the antibacterial glass in the core portion is Q1 (wt%) relative to the total amount of the antibacterial fiber and the content of the antibacterial glass in the sheath portion is Q2 (wt%), Q1 and Q2 satisfy the following relational expression (1).

Q1＜Q2(1)

Accordingly, the content of the antimicrobial glass in the core portion can be made smaller than the content of the antimicrobial glass in the sheath portion, and therefore the antimicrobial fiber can have a concentration distribution of the antimicrobial glass, and can exhibit excellent antimicrobial properties.

Further, it is more preferable that Q1 and Q2 satisfy the following relational expression (2).

0＜Q2－Q1≤10 (2)

The reason is that: this makes it possible to optimize the concentration distribution of the antimicrobial glass in the antimicrobial fiber.

Therefore, as Q1 and Q2 satisfying such relational expressions, Q1 is preferably 0 wt% or less than 1 wt% excluding 0 wt%, and Q2 is preferably a value in the range of 1 to 10 wt%. Further, Q1 is more preferably 0% by weight or less than 0.5% by weight, and Q2 is more preferably 1.5 to 9% by weight. Further, it is more preferable that Q1 be 0% by weight or less than 0.1% by weight, and it is further preferable that Q2 be a value in the range of 2 to 8% by weight.

The reason for this is that: when the value of Q1 is within this range, the antibacterial effect of the antibacterial glass can be effectively obtained even when the average diameter of the antibacterial fiber is small. On the other hand, the reason is that: when Q2 has a value within this range, the content of the antimicrobial glass relative to the entire antimicrobial fiber can be set within an appropriate range.

(5) Tensile strength

In addition, as the antibacterial fiber of the present embodiment, from the viewpoint of giving sufficient strength to the product when processed into a textile or the like, it is preferable that the tensile strength (cN/dtex) measured according to JIS L1015 is a value in the range of 3 to 50 cN/dtex.

The reason for this is that: when the tensile strength (cN/dtex) of the antibacterial fiber is less than 3cN/dtex, the fiber may be broken during stretching, or the product using the antibacterial fiber may be torn during washing or the like.

On the other hand, the reason is that: if the tensile strength (cN/dtex) of the antibacterial fiber exceeds 50cN/dtex, the antibacterial fiber may have insufficient flexibility and may be used in an excessively limited range.

Therefore, the tensile strength (cN/dtex) of the antibacterial fiber is more preferably within a range of 3.5 to 30cN/dtex, and still more preferably within a range of 4.5 to 20 cN/dtex.

(6) Others

The apparent fineness (see degrees) and the number of curls of the antimicrobial fiber are not particularly limited, and can be appropriately adjusted depending on the use of the antimicrobial fiber.

The apparent fineness of the antibacterial fiber can be suitably adjusted depending on the application, and is, for example, preferably in the range of 0.1 to 50dtex, more preferably in the range of 0.5 to 30dtex, and still more preferably in the range of 1 to 10 dtex.

The number of crimps of the antibacterial fiber can be adjusted according to the application from the viewpoints of imparting elasticity, feeling, and the like, and the larger the number of crimps, the more the elasticity is.

The antimicrobial fiber usually has a crimp number of 5 to 90 per 25mm fiber, and preferably 50 to 90 for applications requiring elasticity.

4. Dispersing aid

The antimicrobial fiber in the present embodiment preferably contains a dispersing aid for the antimicrobial glass.

The reason for this is that: by containing the dispersion aid, the antimicrobial glass can be dispersed more uniformly.

(1) Species of

The type of the dispersion aid is not particularly limited, and for example, an aliphatic amide-based dispersion aid, a hydrocarbon-based dispersion aid, a fatty acid-based dispersion aid, a higher alcohol-based dispersion aid, a metal soap-based dispersion aid, an ester-based dispersion aid, and the like can be used.

The fatty amide-based dispersing aid can be roughly classified into fatty acid amides such as stearic acid amide, oleic acid amide, and erucic acid amide, and alkylene fatty acid amides such as methylene bis-stearic acid amide and ethylene bis-stearic acid amide, and the alkylene fatty acid amides are more preferably used.

The reason for this is that: when the alkylene fatty acid amide is used, the dispersibility of the antimicrobial glass can be improved without lowering the thermal stability of the antimicrobial resin composition as compared with a fatty acid amide.

Further, ethylene bis-stearamide is particularly preferably used as the alkylene fatty acid amide because the melting point is 141.5 to 146.5 ℃ and the antibacterial fiber is excellent in stability during molding.

(2) Compounding amount

The amount of the dispersing aid is preferably in the range of 1 to 20 parts by weight, based on 100 parts by weight of the antimicrobial glass.

The reason for this is that: if the amount of the dispersing aid is 1 part by weight or more, the dispersibility of the antimicrobial glass in the antimicrobial fiber can be sufficiently improved.

On the other hand, the reason is that: when the amount of the dispersing aid is 20 parts by weight or less, the dispersing aid is less likely to bleed out from the antibacterial resin composition while sufficiently ensuring mechanical properties such as tensile strength and tear strength of the antibacterial resin composition.

Therefore, the amount of the dispersing aid to be added is more preferably in the range of 3 to 12 parts by weight, and still more preferably in the range of 5 to 8 parts by weight, based on 100 parts by weight of the antimicrobial glass.

5. Other compounding ingredients

It is preferable to add additives such as stabilizers, release agents, nucleating agents, fillers, dyes, pigments, antistatic agents, oils, lubricants, plasticizers, sizing agents, ultraviolet absorbers, antifungal agents, antiviral agents, flame retardants, flame retardant aids, and the like, other resins, elastomers, and the like as optional components as needed within a range that does not impair the original object.

The method for adding these optional components to the antimicrobial fiber is not particularly limited, and for example, it is also preferable to add these optional components by melt-kneading them together with the antimicrobial glass into a thermoplastic resin.

6. Form of the composition

The antibacterial fiber of the present embodiment is preferably processed into sheet-like molded articles such as cotton-like or woven fabrics, nonwoven fabrics, textile fabrics, felts, and nets.

The antibacterial fiber of the present embodiment may be processed using only the antibacterial fiber of the present embodiment, or may be processed into a twisted yarn, a covered yarn, or a cord by blending or blending other types of fibers with the antibacterial fiber of the present embodiment when processed into cotton, woven cloth, nonwoven cloth, woven fabric, felt, net, or the like.

Examples of the other fibers include synthetic fibers such as nylon, polyester, and polyurethane, natural fibers such as cotton and silk, carbon fibers, and glass fibers.

Even when the fiber is mixed and blended with other types of fibers to be processed into a twisted yarn, a covered yarn, or a cord, the antimicrobial fiber of the present embodiment has an antimicrobial property equivalent to that of the antimicrobial fiber of the present embodiment, and has an excellent characteristic of maintaining the antimicrobial property even after repeated washing.

In addition, the antibacterial fiber of the present embodiment or a processed product such as cotton, textile, woven or knitted product obtained by processing the antibacterial fiber according to the use is preferably further subjected to dyeing and various finishing (crease resistance, stain resistance, flame resistance, insect resistance, mold resistance, odor resistance, moisture absorption, water resistance, glazing, pilling resistance, etc.).

This can provide a function other than antibacterial properties.

7. Use of

The applications of the sheet-like molded article in the above-described embodiments are not particularly limited, and examples thereof include clothing, bedding, upholstery, absorbent cloth, packaging materials, miscellaneous goods, and filter media.

Examples of the clothing include underwear, shirts, sportswear, aprons, socks, shoe pads, stockings, tights, japanese socks, and kins, ties, handkerchiefs, shawl, scarf, hat, gloves, and masks for home or medical use.

Examples of bedding include a sheet cover, a sheet core, a pillow cover, a pillow core, a towel, a sheet, and a bed cover. Is especially suitable for the beddings which are difficult to wash, such as down bedding, down pillows, and the like.

Examples of upholstery include curtains, mats, carpets, rugs, cushions, wall coverings, table coverings, and short pile fabrics.

Examples of the absorbent cloth include towels, wiping cloths, handkerchiefs, mops, diapers, tampons, sanitary napkins, adult incontinence products, and the like.

Examples of the wrapping material include a bundle, a wrapping paper, and a food packaging bag.

Examples of miscellaneous goods include various brushes such as a toothbrush, a broom, and a scrubbing brush, a handbag, a lunch pad, a pen bag, a wallet, a spectacle case, a spectacle wiper, a door curtain, a cup pad, a mouse pad, wadding for a doll, and a pet bed.

Examples of the filter medium include air conditioners, ventilation fans, ventilation openings, filters for air cleaners, and filters for water purification, and can be used for filters for home use, industrial use, automobiles, and the like.

Other applications include artificial hair, light-shielding sheets such as tents and lawn protection sheets, sound-insulating materials, sound-absorbing materials, and cushioning materials.

[ 2 nd embodiment ]

The feature of the 2 nd embodiment is: the method for producing an antibacterial fiber according to embodiment 1 is a method for producing an antibacterial fiber including a core portion and a sheath portion and containing a thermoplastic resin and an antibacterial glass as compounding components, and the method for producing an antibacterial fiber includes the following steps (1) to (3).

Step (1): process for preparing antimicrobial glass

Q1＜Q2 (1)

step (3): using a core-sheath composite spinning die head to perform composite spinning to form a core part from a spinning solution for the core part and a sheath part from the spinning solution for the sheath part, and to prepare an antibacterial fiber with an average diameter of 10-30 μm,

hereinafter, a method for producing an antibacterial fiber according to embodiment 2 will be described in detail mainly focusing on differences from embodiment 1.

The antibacterial fiber of the present embodiment can be produced by a production method having at least the above steps (1) to (3), and the following steps (4) to (6) may be added as necessary.

1. Step (1): process for preparing antimicrobial glass

The step (1) is a step of producing an antimicrobial glass from a glass raw material containing an antimicrobial active ingredient.

That is, the antimicrobial glass can be produced by a conventionally known method, and is preferably produced by a method comprising the following (1) -1 to 3, for example.

(1) -1 melting procedure

In the melting step, it is preferable to weigh the glass raw materials accurately, mix them uniformly, and melt them in, for example, a glass melting furnace to obtain a glass melt.

When the glass material is mixed, it is preferable to use a mixing machine (stirrer) such as a universal stirrer (planetary stirrer), an alumina magnetic mill, a ball mill, or a propeller stirrer, and when a universal stirrer is used, it is preferable to stir and mix the glass material under conditions of a revolution number of 100rpm and a rotation number of 250rpm for 10 minutes to 3 hours.

The glass melting conditions are preferably, for example, a melting temperature of 1100 to 1500 ℃ and a melting time of 1 to 8 hours.

The reason for this is that: such melting conditions can improve the productivity of the glass melt and reduce the yellowing of the antimicrobial glass during production as much as possible.

After obtaining such a glass melt, it is preferably poured into flowing water to cool the glass melt, and the glass melt is pulverized with water to obtain a glass body.

(1) -2 crushing step

Next, as a pulverization step, the obtained glass body is pulverized to prepare an antimicrobial glass having a polyhedron and a predetermined volume average particle diameter.

Specifically, coarse pulverization, intermediate pulverization, and fine pulverization as described below are preferably performed.

By doing so, an antimicrobial glass having a uniform volume average particle diameter can be efficiently obtained.

Among them, in order to control the volume average particle diameter more finely according to the application, it is preferable to further perform classification after pulverization, and perform a sieving treatment or the like.

In the coarse pulverization, the glass body is preferably pulverized so that the volume average particle diameter becomes about 10 mm.

More specifically, it is preferable to pulverize the glass melt in a molten state into a glass body with water or to pulverize an amorphous glass body into a predetermined volume average particle diameter by hand or with a hammer or the like.

It was confirmed from the electron micrograph that the coarsely ground antimicrobial glass was generally in the form of a lump having no corners.

In the intermediate pulverization, the antibacterial glass after the coarse pulverization is preferably pulverized so that the volume average particle diameter is about 1 mm.

More specifically, for example, it is preferable to prepare an antimicrobial glass having a volume average particle size of about 10mm into an antimicrobial glass having a volume average particle size of about 5mm by using a ball mill, and then prepare an antimicrobial glass having a volume average particle size of about 1mm by using a rotary mill or a rotary roll (roll crusher).

The reason for this is that: by performing the grinding in multiple stages in this manner, an antimicrobial glass having a predetermined particle diameter can be efficiently obtained without producing an antimicrobial glass having an excessively small particle diameter.

It was confirmed from the electron micrograph that the antibacterial glass after pulverization was polyhedral with corners.

In the fine grinding, it is preferable that the antibacterial glass after the intermediate grinding is ground so that the volume average particle diameter is 1.0 to 5.0 μm in a state where the aggregated silica particles as the external additive having the volume average particle diameter of 1 to 15 μm are added.

More specifically, for example, it is preferable to crush the antibacterial glass using a rotary mill, a rotary roller (roll crusher), a vibration mill, a vertical mill, a dry ball mill, a planetary mill, a sand mill, or a jet mill.

Among these dry pulverizers, particularly, a longitudinal mill, a dry ball mill, a planetary mill, and a jet mill are more preferably used.

The reason for this is that: by using a vertical mill, a planetary mill, or the like, an appropriate shearing force can be applied, and a polyhedral antibacterial glass having a predetermined particle diameter can be efficiently obtained without generating an antibacterial glass having an excessively small particle diameter.

When micro-grinding is performed using a vertical mill, a dry ball mill, a planetary mill, or the like, it is preferable to perform grinding treatment for 5 to 50 hours on the antibacterial glass after the intermediate grinding by rotating a container at 30 to 100rpm using zirconia balls or alumina balls as a grinding medium.

When a jet mill is used, it is preferable to accelerate the reaction in a container to a pressure of 0.61 to 1.22MPa (6 to 12 Kgf/cm)²) The pressure of (3) causes the crushed antimicrobial glasses to collide with each other.

It was confirmed from the electron micrograph and the particle size distribution measurement that the antimicrobial glass after micro-grinding using a dry ball mill, a jet mill, or the like was a polyhedron having more angles than the antimicrobial glass after medium-grinding, and the volume average particle diameter (D50) and the specific surface area were easily adjusted to predetermined ranges.

In addition, when fine grinding is performed using a planetary mill or the like, it is preferable to perform the grinding substantially in a dry state (for example, with a relative humidity of 20% Rh or less).

The reason for this is that: the circulation may be performed without coagulating the antimicrobial glass by installing a classifying device such as a cyclone separator in a planetary mill or the like.

Therefore, the volume average particle diameter and the particle size distribution of the antimicrobial glass can be easily adjusted to a desired range by controlling the number of cycles, and the drying step after the slight pulverization can be omitted.

On the other hand, antimicrobial glass in a dry state within a predetermined range or less can be easily removed by using a bag filter.

Therefore, the volume average particle diameter and the particle size distribution of the antimicrobial glass can be adjusted more easily.

(1) -3 drying procedure

Next, the antimicrobial glass obtained in the grinding step is preferably dried in a drying step.

The reason for this is that: by drying the antimicrobial glass, the possibility of hydrolysis of the thermoplastic resin when the antimicrobial glass and the thermoplastic resin are mixed in the following step can be reduced.

In the drying step, it is preferable to perform the drying treatment also after the solid-liquid separation treatment, and the equipment used for these treatments is not particularly limited, and a centrifugal separator or the like may be used for the solid-liquid separation, and a dryer, an oven or the like may be used for the drying.

Further, after the step of drying the antimicrobial glass, since a part of the antimicrobial glass is agglomerated, it is preferable to disintegrate the agglomerated antimicrobial glass by a disintegrator.

2. Step (2): process for preparing spinning dope

The step (2) is a step of producing a spinning dope using the antimicrobial glass obtained in the step (1).

In the step (2), the antimicrobial glass or a master batch in which the antimicrobial glass is dispersed in the thermoplastic resin is preferably melt-kneaded with the resin particles or the regenerated resin chips to produce a spinning dope.

In addition, it is also preferable to further add additives such as a coloring master batch, an antioxidant, an internal lubricant, and a crystallizing agent in the step (2).

In the step (2), when the content of the antimicrobial glass in the core part is Q1 (wt%) relative to the total amount of the antimicrobial fibers and the content of the antimicrobial glass in the sheath part is Q2 (wt%) relative to the total amount of the antimicrobial fibers, the obtained antimicrobial glasses are mixed and dispersed so that Q1 and Q2 satisfy the following relational expression (1) to adjust the spinning dope for the core part and the spinning dope for the sheath part.

Q1＜Q2 (1)

Here, Q1 is preferably 0 wt% or less than 1 wt% excluding 0 wt%, and Q2 is preferably 1 to 10 wt%.

When a polyethylene terephthalate resin is used as the main component as the thermoplastic resin, it is preferable to mix and disperse a polybutylene terephthalate resin.

This is due to: the hydrolysis of the polyethylene terephthalate resin as the main component can be effectively suppressed, and a spinning dope in which the antibacterial glass at the final concentration is uniformly dispersed can be obtained.

3. Step (3): process for producing antibacterial fiber

The antibacterial fiber of the present invention can be produced by the same method as a conventionally known method for composite fibers. In the spinning, melt spinning and solution spinning are used, and a method thereof is selected depending on the resin used.

In the step (3), it is preferable to form a fiber by introducing the molten dope for the core portion into the core portion, introducing the dope for the sheath portion into the sheath portion, discharging the dope from the die, and then thermally drawing the dope by using a core-sheath composite spinning die.

Here, the spinning dope for the core portion and the spinning dope for the sheath portion mean molten resins obtained by thermally melting the resins in the case of melt spinning, and mean dopes in a state where the resins are dissolved in a solvent in the case of solution spinning.

The yarn ejected from the die is usually cooled, and the cooling method is not particularly limited, and a method of blowing cold air to the spun yarn can be preferably exemplified.

The spinning is preferably carried out in a two-step process such as winding or storing in a metal can, if necessary, followed by a stretching treatment.

As the apparatus used for spinning, a conventionally known apparatus can be used.

For example, a pressure-melt type spinning machine, or a single-screw or twin-screw extruder type spinning machine is preferably used.

The reason for this is that: by using such a molding apparatus, an antibacterial fiber having excellent surface smoothness can be effectively obtained.

The shape of the spun yarn is not particularly limited, and it may be circular, flat, hexagonal, star-shaped, or other polygonal shape.

The spinning temperature is preferably 240 ℃ to 320 ℃ and the winding speed is preferably 100m/min to 6000m/min, although this is an example.

Next, the spun fiber is drawn.

The stretching step can be carried out by a conventionally known method and apparatus, and for example, a direct spinning method or a roll stretching method is preferably used. When spinning and drawing are carried out separately, a warm water bath is preferably used.

The direct spin draw process is carried out by: after spinning, the fiber is once cooled to a temperature not lower than the glass transition temperature, and then wound while running in a tubular heating device having a temperature range not lower than the glass transition temperature but not higher than the melting point.

The roll stretching method is performed by the following method: the yarn is wound and drawn by a drawing roll rotating at a predetermined speed, and the drawn yarn is drawn in one or more stages by a roll group set to a temperature not lower than the glass transition temperature of the thermoplastic resin but not higher than the melting point.

The warm water bath is carried out by immersing the fiber in warm water at 60 to 90 ℃, preferably 80 ℃.

The stretch ratio is preferably 1.2 times or more from the viewpoint of improving the mechanical strength.

The upper limit of the draw ratio is not particularly limited, but is preferably 7 times or less from the viewpoint of preventing yarn breakage due to over-drawing.

4. Step (4): curling Process

The crimping step in step (4) is an arbitrary step, and is a step of introducing the drawn yarn obtained in step (3) into a crimping device and subjecting the yarn to false twisting to impart bulkiness and stretchability.

In the crimping step, a conventionally known method or device may be used, and for example, a heated fluid crimping device that brings a heated fluid into contact with the yarn to false twist the yarn is preferably used.

The heated fluid crimping device is a device that applies crimp by injecting a heated fluid such as steam to the yarn and pressing the yarn and the heated fluid into the compression adjustment part together.

Here, the temperature of the heating fluid is preferably a value in the range of 100 to 150 ℃.

The reason for this is that: if the temperature is within the above range, sufficient crimping can be obtained and fusion of the fibers with each other can be avoided.

Therefore, the temperature of the heating fluid is more specifically set to a value within a range of 110 to 145 ℃, and more preferably 115 to 140 ℃.

5. Step (5): post-treatment Process

The post-treatment step of step (5) is also an arbitrary step, and is a step of applying an oil to the crimped yarn obtained in step (4), drying the resultant yarn with a dryer, introducing the yarn into a thermosetting roll, and adjusting the elongation according to the heating temperature.

The temperature of the thermosetting roller is preferably in the range of 130 to 160 ℃ from the viewpoint of preventing troubles between winding rollers, wrinkle failures, and the like during fiber processing, fabric formation, and the like.

More specifically, the temperature of the thermosetting roller is preferably 135 to 155 ℃, and more preferably 140 to 150 ℃.

6. Step (6): dyeing process

The dyeing step in the step (6) is also an arbitrary step, and is a step of dyeing the antibacterial fiber which is crimped and/or heat-set as necessary after stretching, under alkaline conditions or acidic conditions.

In the dyeing step, conventionally known methods and apparatuses can be used, and for example, hand dyeing, push dyeing, jet dyeing, circular hank dyeing, austenitic dyeing, and cheese dyeing are preferably used.

The dyeing liquid preferably contains, together with the dye, dyeing auxiliaries such as leveling agents, dyeing promoters and metal blocking agents, dye-fastness enhancers and fluorescent brighteners as necessary.

When dyeing is performed under alkaline conditions, the pH can be adjusted to 7.5 to 10.5, and carbonates such as calcium carbonate and sodium hydroxide are preferably used for pH adjustment.

When dyeing is performed under acidic conditions, the pH can be adjusted to 3.5 to 6.5, and organic acids such as acetic acid, citric acid, malic acid, fumaric acid, and succinic acid, and salts thereof are preferably used for adjusting the pH.

After dyeing, batch washing is preferably performed, and reduction washing or soaping is further preferably performed.

The washing conditions may be those used for conventional polyester fibers, and in the case of reductive washing, 0.5 to 3g/L of each of a reducing agent, an alkali, and sodium dithionite are used, and the treatment is preferably carried out at 60 to 80 ℃ for 10 to 30 minutes.

Examples

Hereinafter, the following examples are used to describe the present invention more specifically.

However, the present invention is not limited to the following examples without any particular reason.

[ example 1]

1. Production of antibacterial glass

(1) Melting step

P is calculated by taking the total amount of the antimicrobial glass as 100 wt%₂O₅Has a composition ratio of 50 wt%, CaO 5 wt%, and Na₂The composition ratio of O was 1.5% by weight, and B was₂O₃Is 10 wt% of Ag₂The composition ratio of O was 3% by weight, and CeO₂The glass materials were stirred at 250rpm for 30 minutes using a universal mixer until they were uniformly mixed so that the composition ratio of (1) was 0.5 wt% and the composition ratio of ZnO was 30 wt%.

Next, the glass raw material was heated at 1280 ℃ for 3 hours and half hours in a melting furnace to prepare a molten glass.

(2) Coarse grinding process

The molten glass taken out of the glass melting furnace was poured into still water at 25 ℃ to pulverize the molten glass with water, thereby obtaining roughly pulverized glass having a volume average particle size of about 10 mm.

The coarsely ground glass at this stage was observed with an optical microscope, and it was confirmed that the glass was massive and had no corners and surfaces.

(3) Middle crushing process

Next, the resultant was pulverized in one step (volume average particle diameter: about 1000 μm) while feeding coarsely pulverized glass by its own weight from a hopper under the condition of a gap of 1mm and a rotation speed of 150rpm by using a pair of alumina-made rotating rolls (RollCrusher, manufactured by Tokyo ATOMIZER Co., Ltd.).

Further, the coarsely ground glass obtained by the primary grinding was subjected to secondary intermediate grinding using a rotary mill made of alumina (PremaX, manufactured by Central chemical engineering Co., Ltd.) at a gap of 400 μm and a rotation speed of 700rpm to obtain intermediate ground glass having a volume average particle diameter of about 400 μm.

When the crushed glass was observed with an electron microscope, at least 50% by weight of the crushed glass was polyhedral with corners and faces.

(4) Micro-grinding process

Then, 210kg of alumina balls having a diameter of 10mm as a medium, 20kg of medium-crushed glass having been subjected to secondary medium-crushing, 14kg of isopropyl alcohol, and 0.2kg of a silane coupling agent A-1230 (manufactured by NIUC corporation) were placed in a vibrating ball mill (manufactured by CENTRIFUL CORPORATION CO., LTD.) having an internal volume of 105 liters, and then, the medium-crushed glass was subjected to a micro-crushing treatment at a rotation speed of 1000rpm and a vibration width of 9mm for 7 hours to obtain micro-crushed glass.

When the finely ground glass was observed with an electron microscope, at least 70% by weight of the finely ground glass was polyhedral with corners and faces.

(5) Solid-liquid separation and drying step

The finely ground glass obtained in the previous step and isopropyl alcohol were subjected to solid-liquid separation using a centrifuge (manufactured by kokusan corporation) at 3000rpm for 3 minutes.

Next, the finely ground glass was dried at 105 ℃ for 3 hours in an oven.

(6) Breaking process

The finely ground glass, which was partially agglomerated after drying, was disintegrated using a gear-type disintegrator (manufactured by CENTRAL CHEMICAL MACHINES), to obtain an antibacterial glass (polyhedral glass) having a volume average particle diameter of 1.0. mu.m.

When the antimicrobial glass at this stage was observed with an electron microscope, it was confirmed that at least 90% by weight of the antimicrobial glass was polyhedral with corners and faces.

2. Production of antibacterial fiber

(1) Spinning step

(1) -1 preparation of the spinning dope for the core

100 parts by weight of a polyethylene terephthalate resin having a number average molecular weight of 34000 was mixed and dispersed at a cylinder temperature of 250 ℃ and a screw rotation speed of 30rpm by using a BMC (bulk molding compound) injection molding apparatus to prepare a spinning dope for a core.

(1) -2 preparation of spinning dope for sheath portion

Using a BMC (bulk molding compound) injection molding apparatus, 7 parts by weight of an antimicrobial glass, 95 parts by weight of a polyethylene terephthalate resin having a number average molecular weight of 34000, and 5 parts by weight of a polybutylene terephthalate resin having a number average molecular weight of 26000 were mixed and dispersed at a cylinder temperature of 250 ℃ and a screw rotation speed of 30rpm to prepare a spinning dope for a sheath portion.

The antibacterial resin composition having the above compounding ratio is finally obtained by mixing a predetermined amount of the antibacterial glass with the polybutylene terephthalate resin to prepare a master batch, and then mixing the polyethylene terephthalate resin with the master batch to thereby suppress hydrolysis of the polyethylene terephthalate resin.

(1) -3 composite spinning

The core part spinning dope was used for the core part, the sheath part spinning dope was used for the sheath part, and the antibacterial fiber was spun from a core-sheath composite spinning die having 24 circular composite spinning holes with a nozzle diameter of 0.3mm at a spinning temperature of 285 ℃ and a winding speed of 3000m/min at a core-sheath weight ratio of 50/50.

(2) Drawing step

Then, the resultant was passed through a tubular heating apparatus and heated to 90 ℃ and simultaneously stretched to 3 times, thereby obtaining an antimicrobial fiber having an average diameter of 40 μm. Further, the average diameter of the core was 30 μm.

3. Evaluation of antibacterial fibers

(1) Observation with an electron microscope

The obtained antimicrobial fiber was observed with a scanning electron microscope (JSM-6610 LA, manufactured by Nippon electronics Co., Ltd.), and as a result, it was found that the antimicrobial glass was dispersed only in the sheath portion of the antimicrobial fiber in the form of white dots. In addition, the black dots are bubbles. The results are shown in FIG. 3.

In addition, the presence or absence of metal ions can also be determined by scanning electron microscopy images and elemental surface scanning. That is, EDX measurement (JED-2300, manufactured by JEOL Ltd.) was performed, and the distribution state of the constituent elements was determined by surface scanning analysis. The results are shown in fig. 4 (a) to (c).

Here, fig. 4 (a) to (C) show EDX plane scan images obtained using characteristic X-rays of a P (phosphorus) element K line (fig. 4 (a)), a C (carbon) element K line (fig. 4 (b)), and an O (oxygen) element K line (fig. 4 (C)).

From (a) in fig. 4, that is, an EDX plane scan image of characteristic X-rays using K-lines of P elements, it can be seen that: the antimicrobial glass of the antimicrobial fiber of the present invention is not uniformly distributed over the entire antimicrobial fiber, and a plurality of regions having a locally high concentration distribution are present in the sheath portion. In addition, from fig. 4 (b), it can be seen that: the positions where the antibacterial fibers are distributed are not distributed with C elements. Further, from fig. 4 (c), it can be seen that: and O elements are uniformly distributed.

(2) Short fiber test of chemical fiber

The antibacterial fiber obtained in example 1 was measured for tensile strength in accordance with JIS L1015, and evaluated in accordance with the following criteria.

The initial load in the tensile strength measurement was 5.88mN/1tex, the tensile rate was 20mm/min, and the nip gap was 10 mm. The obtained results are shown in table 1.

Very good: the tensile strength is more than 3cN/dtex and less than 8cN/dtex

Good: a tensile strength of 2cN/dtex or more and less than 10cN/dtex (excluding a range of 3cN/dtex or more and less than 8 cN/dtex.)

And (delta): a tensile strength of 1cN/dtex or more and less than 12cN/dtex (excluding a range of 2cN/dtex or more and less than 10 cN/dtex.)

X: the tensile strength is less than 1cN/dtex and more than 12cN/dtex

(3) Evaluation of antibacterial Properties 1 to 2

On the other hand, the test bacteria were cultured at 35 ℃ for 24 hours in an Agar plate medium of trypticasoy Agar (BBL) to suspend the developing colonies in a common broth medium (manufactured by Rough chemical Co., Ltd.) having a concentration of 1/500, and the concentration was adjusted to about 1 × 10⁶CFU/ml。

Then, 0.5ml of a suspension of Staphylococcus aureus (Staphylococcus aureus IFO #12732) and 0.5ml of a suspension of Escherichia coli (Escherichia coli ATCC #8739) were brought into uniform contact with the antimicrobial fibers as test pieces, and further, polyethylene films were placed (sterilized) to prepare measurement samples for film coating.

Subsequently, the measurement sample was placed in a thermostatic bath at a humidity of 95%, a temperature of 35 ℃ and 24 hours, the number of bacteria before the test (developmental colony) and the number of bacteria after the test (developmental colony) were measured, and the antibacterial properties 1 (staphylococcus aureus) and 2 (escherichia coli) were evaluated in accordance with the following criteria.

The number of bacteria (developing colonies) before the test was 2.6 × 10 for each of Staphylococcus aureus and Escherichia coli⁵(pieces/test piece). The results obtained are shown in table 1.

Very good: the number of bacteria after the test was less than 1/10000 of the number of bacteria before the test.

Good: the number of bacteria after the test is 1/10000 or more and 1/1000 or less of the number of bacteria before the test.

And (delta): the number of bacteria after the test is 1/1000 or more and 1/100 or less of the number of bacteria before the test.

X: the number of bacteria after the test is 1/100 or more of the number of bacteria before the test.

[ example 2]

An antibacterial fiber was produced in the same manner as in example 1 except that the antibacterial glass in the sheath portion was 10 parts by weight and the thermoplastic resin was 100 parts by weight of a polypropylene resin having a number average molecular weight of 60000 in example 2, and the fiber evaluation and the antibacterial evaluation were performed in the same manner as in example 1. The obtained results are shown in table 1.

As a result of observation of the antimicrobial fiber obtained in example 2 with a scanning electron microscope, the antimicrobial glass dispersed only in the sheath portion of the antimicrobial fiber was observed in the same manner as in example 1. The results are shown in FIG. 1.

In addition, EDX measurement was performed in the same manner as in example 1, and the distribution state of the constituent elements was determined qualitatively by surface scanning analysis. The results are shown in fig. 5 (a) to (c).

Here, fig. 5 (a) to (C) show EDX plane scan images obtained using characteristic X-rays of a P (phosphorus) element K line (fig. 5 (a)), a C (carbon) element K line (fig. 5 (b)), and an O (oxygen) element K line (fig. 5 (C)).

From fig. 5 (a), it can be seen that: the antimicrobial glass is not distributed over the entire antimicrobial fiber, and a plurality of regions having a local high concentration distribution exist in the sheath portion. In addition, from fig. 5 (b), it can be seen that: the sheath part is brighter, and C elements are distributed more. Further, from fig. 5 (c), it can be seen that: the core part is brighter due to the O element contained in the core part, namely polyethylene terephthalate and polybutylene terephthalate.

[ example 3]

An antimicrobial fiber was produced in the same manner as in example 1 except that in example 3, the sheath spinning dope was composed of 3 parts by weight of an antimicrobial glass, 95 parts by weight of a polyethylene terephthalate resin having a number average molecular weight of 34000, and 5 parts by weight of a polybutylene terephthalate resin having a number average molecular weight of 26000, and fiber evaluation and antimicrobial evaluation were performed in the same manner as in example 1. The obtained results are shown in table 1.

As a result of observation of the antimicrobial fiber obtained in example 3 with a scanning electron microscope, the antimicrobial glass dispersed only in the sheath portion of the antimicrobial fiber was observed in the same manner as in example 1.

[ example 4]

An antibacterial fiber was produced in the same manner as in example 1 except that in example 4, the spinning dope for the core portion was composed of 0.5 parts by weight of an antibacterial glass, 95 parts by weight of a polyethylene terephthalate resin having a number average molecular weight of 34000, and 5 parts by weight of a polybutylene terephthalate resin having a number average molecular weight of 26000, and fiber evaluation and antibacterial evaluation were performed in the same manner as in example 1. The obtained results are shown in table 1.

As a result of observation of the antimicrobial fiber obtained in example 4 with a scanning electron microscope, it was found that the antimicrobial glass was further dispersed in the sheath portion of the antimicrobial fiber.

Comparative example 1

An antibacterial fiber was produced in the same manner as in example 1 except that the sheath spinning dope was the same as the core spinning dope in comparative example 1, that is, antibacterial glass was not blended in both the core and the sheath, and the fiber evaluation and the antibacterial evaluation were performed in the same manner as in example 1. The obtained results are shown in table 1.

[ Table 1]

Industrial applicability

As described above, according to the present invention, it is possible to obtain an antimicrobial fiber which can exhibit excellent antimicrobial properties by making the content of the antimicrobial glass in the core portion smaller than the content of the antimicrobial glass in the sheath portion, and which can be blended in a small amount, and further can exhibit excellent antimicrobial properties, and an effective method for producing such an antimicrobial fiber.

Therefore, the present invention is expected to contribute significantly to the high quality of antibacterial articles, particularly woven fabrics and nonwoven fabrics, molded using antibacterial fibers.

Claims

1. An antimicrobial fiber comprising a thermoplastic resin and an antimicrobial glass as compounding ingredients, wherein the average diameter of the antimicrobial fiber is set to a value in the range of 1 to 50 [ mu ] m, the antimicrobial fiber is provided with a core part and a sheath part, the content of the antimicrobial glass in the core part is Q1 relative to the total amount of the antimicrobial fiber, and the content of the antimicrobial glass in the sheath part is Q2 relative to the total amount of the antimicrobial fiber, wherein Q1 and Q2 satisfy the following relational expression (1), and the units of Q1 and Q2 are weight%,

Q1＜Q2 (1)。

2. the antimicrobial fiber according to claim 1, wherein the Q1 is 0 wt%, or less than 1 wt% excluding 0 wt%.

3. The antibacterial fiber according to claim 1 or 2, wherein Q2 is a value in the range of 1 to 10 wt%.

4. The antibacterial fiber according to any one of claims 1 to 3, further comprising aggregated silica particles as a blending component.

5. The antibacterial fiber according to any one of claims 1 to 4, wherein the volume average particle diameter of the antibacterial glass is set to a value in the range of 0.1 to 5 μm.

6. The antibacterial fiber according to any one of claims 1 to 5, wherein the thermoplastic resin is at least one of a polyester resin, a polyamide resin and a polyolefin resin.

7. The antibacterial fiber according to any one of claims 1 to 6, wherein the antibacterial fiber is in the form of any one of a woven fabric, a nonwoven fabric and a felt.

8. A method for producing an antibacterial fiber, characterized in that the antibacterial fiber comprises a core part and a sheath part, and contains a thermoplastic resin and an antibacterial glass as compounding ingredients,

the production method comprises the following steps (1) to (3),

step (2): when the content of the antimicrobial glass in the core portion is Q1 (wt%) relative to the total amount of the antimicrobial fibers and the content of the antimicrobial glass in the sheath portion is Q2 (wt%),

preparing a spinning dope for a core portion and a spinning dope for a sheath portion by dispersing the obtained antimicrobial glass in a thermoplastic resin so that Q1 and Q2 satisfy the following relational expression (1),

Q1＜Q2 (1)

step (3): and performing composite spinning using a core-sheath composite spinning die head so that the spinning solution for the core part becomes a core part and the spinning solution for the sheath part becomes a sheath part, thereby obtaining an antibacterial fiber with an average diameter of 1-50 [ mu ] m.