KR20230015022A - Biodegradable fiber having with excellent softness and Method for manufacturing the same - Google Patents

Abstract

The present invention relates to a biodegradable fiber, and a manufacturing method thereof, in which, by mixing and spinning an amorphous polyhydroxy alkanoates (PHA) resin and a polylactic acid (PLA) resin, the biodegradable fiber has reduced brittle properties and excellent flexibility while maintaining the fiber shape by maintaining the appropriate strength, and has excellent biodegradability in the sea.

Description

Biodegradable fiber having excellent softness and method for manufacturing the same {Biodegradable fiber having excellent softness and Method for manufacturing the same}

The present invention relates to a biodegradable fiber having excellent flexibility and a manufacturing method thereof.

Conventionally, synthetic fibers such as polyester, polyolefin, and polyamide have been used as fibers used in living materials, agricultural materials, fishery materials, civil engineering materials, and industrial materials. However, these fibers do not decompose when left in the natural world after use, resulting in serious environmental problems. Therefore, after use, it must be buried in the ground or incinerated, and at this time, environmental problems caused by air pollution or landfill have been highlighted. Accordingly, in recent years, from the viewpoint of global environmental conservation, reduction of the load on the environment is required, and in particular, research on biodegradable materials that do not cause environmental problems by being decomposed in soil, water, or air after use is required.

Such biodegradable polymers include polysaccharides such as cellulose, cellulose derivatives, chitin and chitosan, proteins, poly 3-hydroxybutylate, and microorganisms such as copolymers of 3-hydroxybutyrate and 3-hydroxybarylate. Aliphatic polyesters such as polymers produced by , polyglycolide, polylactic acid (polylactic acid), and polycaprolactone are known.

As an example of the study of the biodegradable polymer, biodegradable polyester fibers were prepared using succinic acid, which is an aliphatic polyester, but in this case, there is a problem in that the degree of biodegradation is low due to the inclusion of a small amount of biodegradable components.

Among the biodegradable polymers, the polylactic acid is an aliphatic polyester-based polymer and since lactic acid or lactide, which is a raw material, can be prepared from natural products, it is not a simple biodegradable polymer, but is easily hydrolyzed in the presence of water and discarded. Since it decomposes without polluting the environment afterward, it is used as a general-purpose polymer with low environmental load.

On the other hand, polyhydroxyalkanoate (PHA) can be prepared by chemical synthesis or biosynthesis using various microorganisms such as bacteria or seaweed, and is generally a semi-crystalline thermoplastic polyester repeating unit. Examples of the PHA polymer include Poly(4-hydrobutyrate) (P4HB), Poly(5-hydroxyvalerate) (PHV), Poly(3-hydroxyhexanoate) (PHH), and Poly(polyhydroxyoctanoate) (PHO).

The biosynthesis of PHA usually occurs under specific deficient conditions (e.g. lack of phosphorus, nitrogen, trace elements, or macroelements such as lack of oxygen) and excess carbon sources, and various forms of hydroxyalkanoates are formed within the cell. Polymerization proceeds, and the physical properties of the polymer change accordingly.

Republic of Korea Patent Registration No. 10-0295015 (registration date: 2001.04.24.)

The present invention for solving the above problems is to form and maintain the shape of the fiber with appropriate strength by mixing and spinning amorphous (amorphous) polyhydroxy alkanoates (PHA) resin and polylactic acid resin. In order to improve the flexibility of existing biodegradable fibers with strong brittleness, and to provide biodegradable fibers with excellent flexibility that are well biodegradable in the sea, and a manufacturing method thereof.

Biodegradable fibers with excellent flexibility of the present invention for solving the above problems include 10 to 30% by weight of an amorphous polyhydroxy alkanoate resin; And the remaining amount of polylactic acid (Polylactic acid, PLA) resin; may include.

As a preferred embodiment of the present invention, the amorphous polyhydroxy alkanoate resin may include a repeating unit represented by Formula 1 below.

As a preferred embodiment of the present invention, the amorphous polyhydroxy alkanoate resin may include 20 to 60 mol% of a repeating unit represented by Formula 1 below.

[Formula 1]

In Formula 1, R ₁ is a straight-chain alkylene group having 1 to 5 carbon atoms, and n is a natural number of 1 to 3.

As a preferred embodiment of the present invention, the amorphous polyhydroxy alkanoate resin may further include a repeating unit represented by Formula 2 below.

[Formula 2]

In Formula 2, R ₂ is a hydrogen atom or a straight-chain alkyl group having 1 to 15 carbon atoms, R ₃ is a straight-chain alkylene group having 1 to 5 carbon atoms, and m is a natural number of 1 to 3.

As a preferred embodiment of the present invention, the amorphous polyhydroxy alkanoate (PHA) resin may include a copolymer represented by Formula 3 below.

[Formula 3]

In Formula 3, R ₁ is a straight-chain alkylene group having 1 to 5 carbon atoms, R ₂ is hydrogen or a straight-chain alkyl group having 1 to 15 carbon atoms, R ₃ is a straight-chain alkylene group having 1 to 5 carbon atoms, and n and m are As a molar ratio, m/n is an integer that satisfies 0.67 to 4.00, and l is an integer that satisfies the weight average molecular weight of the copolymer of 100,000 to 400,000.

As a preferred embodiment of the present invention, the biodegradable fiber has a fiber length (X) and tensile strength (Y) of the fiber, measured by applying a speed of 200 cm / min and a gripping distance of 50 cm through an automatic tensile tester. The slope value of the modulus graph (Y/X) may be 0.45 to 0.68.

As a preferred embodiment of the present invention, the biodegradable fiber may have a fineness of 1.0 to 3.0 de (denier) and a filament number of 30 to 80 fila.

For another object of the present invention, a method for producing a biodegradable fiber having excellent flexibility includes preparing a mixture by mixing a first component and a second component including an amorphous polyhydroxy alkanoate resin; and obtaining biodegradable fibers by sequentially performing a spinning process, a stretching process, and a heat setting process on the mixture.

As a preferred embodiment of the present invention, the second component may include a polylactic acid (PLA) resin.

As a preferred embodiment of the present invention, the mixture may include the first component and the second component in a weight ratio of 1:2.33 to 1:9.0.

As a preferred embodiment of the present invention, the spinning process may be performed at a speed of 1,000 to 6,000 mpm (meters per minute) at 210 to 260 ° C.

The biodegradable fiber of the present invention has excellent flexibility and excellent mechanical properties even though it is well decomposed in the sea.

1 is an image of a cross section of a biodegradable fiber according to an embodiment of the present invention observed through a scanning electron microscope (SEM),
Figure 2 is a flow chart of a method for producing biodegradable fibers according to an embodiment of the present invention,
Figure 3 is a schematic schematic diagram of an apparatus used in manufacturing biodegradable fibers according to an embodiment of the present invention.

Hereinafter, the present invention will be described in more detail.

The polyhydroxy alkanoates (PHA) resin used in the present invention will be described.

The PHA resin is divided into crystalline PHA resin, semi-crystalline PHA resin and amorphous PHA resin, which is represented by the following formula (1) in polyhydroxy alkanoates (PHA) resin It can be determined according to the content of the repeating structure to be.

[Formula 1]

In Formula 1, R ₁ may be a straight-chain alkylene group having 1 to 5 carbon atoms, preferably a straight-chain alkylene group having 2 to 4 carbon atoms. In Formula 1, n may be a natural number of 1 to 3, preferably a natural number of 1 to 2.

Specifically, first, the crystallized PHA resin refers to a case in which the repeating unit represented by Formula 1 is not included in the PHA resin, and the semi-crystalline PHA resin is represented by Formula 1 above. This means that the repeating unit represented by Formula 1 is contained in 5 to 15 mol% of the PHA resin, and the amorphous PHA resin contains 20 to 60 mol% of the repeating unit represented by Formula 1 in the PHA resin. can mean including

The present invention solves the problem of high brittleness of conventional biodegradable fibers by introducing the amorphous polyhydroxy alkanoates (PHA) resin as a component of biodegradable fibers. Excellent flexibility and high biodegradability in the ocean can all be realized.

Hereinafter, a biodegradable fiber having excellent flexibility according to an embodiment of the present invention will be described in more detail.

The biodegradable fiber is an amorphous polyhydroxy alkanoate (PHA) resin; And the remaining amount of polylactic acid (Polylactic acid, PLA) resin; may include.

Referring to each component constituting the biodegradable fiber, first, the amorphous polyhydroxy alkanoate (PHA) resin may be included in 10 to 30% by weight of the total weight of the fiber, preferably 15 to 25% by weight % can be included.

If the amorphous PHA resin is included in less than 10% by weight of the total weight of the biodegradable fiber, not only the flexibility of the fiber may be insufficient, but also the fiber fineness cannot be maintained constant, resulting in a problem in that the shape of the fiber is not properly formed. There may be, and if it contains more than 30% by weight, spinnability problems such as fiber breakage occur when the amorphous PHA resin and polylactic acid (PLA) resin are conjugately spun, and winding is not performed properly. problems may arise.

In addition, the amorphous PHA resin may include a copolymer containing 20 to 60 mol%, preferably 35 to 55 mol%, of the repeating unit represented by Chemical Formula 1.

At this time, when the repeating unit represented by Formula 1 is less than 20 mol%, the PHA resin has a semi-crystalline property, which may cause a problem of deterioration in flexibility, and when it contains more than 60 mol%, the amorphous PHA resin And when conjugate spinning of polylactic acid (PLA) resin, spinning problems such as breakage of fibers and problems such as poor winding may occur.

In addition, the amorphous PHA resin may include a copolymer including a repeating unit represented by Chemical Formula 2 below in mol% of a residual amount excluding the repeating unit represented by Chemical Formula 1.

[Formula 2]

In Formula 2, R ₂ may be hydrogen or a linear alkyl group having 1 to 15 carbon atoms, preferably hydrogen or a linear alkyl group having 1 to 10 carbon atoms, more preferably hydrogen or a linear alkyl group having 1 to 5 carbon atoms. It may be a straight-chain alkyl group, R ₃ may be a straight-chain alkylene group having 1 to 5 carbon atoms, preferably a straight-chain alkylene group having 1 to 3 carbon atoms, m may be a natural number of 1 to 3, Preferably, m may be a natural number of 1 to 2.

In addition, the amorphous PHA resin including repeating units represented by Chemical Formulas 1 and 2 described above may include a copolymer represented by Chemical Formula 3 below.

[Formula 3]

In Formula 3, l may be an integer that satisfies the weight average molecular weight of the copolymer of 100,000 to 400,000, preferably the weight average molecular weight of the copolymer is 150,000 to 380,000, more preferably the weight average molecular weight of the copolymer. It may be an integer that satisfies 260,000 to 360,000. In addition, since R ₁ , R ₂ and R ₃ are the same as those described in Formula 1 and Formula 2, they will be omitted. However, n and m in Formula 3 are molar ratios, m/n is an integer satisfying 0.67 to 4.00, preferably m/n is an integer satisfying 0.80 to 3.00.

The biodegradable fiber of the present invention may include the remaining amount of polylactic acid (PLA) resin out of 100% by weight excluding the amorphous PHA resin. At this time, since the polylactic acid resin serves to secure the strength of the fiber, the more polylactic acid is included in the fiber, the higher the modulus value of the fiber, but also the stronger the brittle property. It is preferable to improve the flexibility of the fiber by mixing and spinning with the amorphous PHA resin having a like) property.

The biodegradable fiber of the present invention has excellent strength, excellent fiber shape retention, good flexibility, and excellent biodegradability in the sea.

The biodegradable fiber of the present invention is a modulus graph (Y/X) of fiber length (X) and tensile strength (Y) of the fiber, measured by applying a speed of 200 cm/min and a gripping distance of 50 cm through an automatic tensile tester. The slope (ΔY/ΔX) value of may be 0.45 to 0.68, preferably 0.47 to 0.65. At this time, if the slope value of the modulus graph is less than 0.45, there may be a problem of reducing the strength of the fiber, and if it exceeds 0.68, the fiber has good strength, but the flexibility is greatly reduced and there may be a problem of being too brittle.

In addition, the biodegradable fiber may have a fineness of 1.0 to 3.0 de (denier), preferably 1.3 to 2.5 de.

In addition, the number of filaments of the biodegradable fiber may be 30 to 80 fila, preferably 35 to 75 fila.

As shown in the schematic diagram of FIG. 3, the biodegradable fiber of the present invention described above includes a first step of preparing a mixture by mixing a first component and a second component; It can be prepared by performing a process including; and a second step of obtaining a biodegradable fiber by sequentially performing a spinning process, a stretching process, and a heat setting process on the mixture.

In the manufacturing method described later, the overlapping part with the part described in the biodegradable fiber described above is omitted and described.

First, the first component may include the amorphous PHA resin described above, and the second component may include polylactic acid (PLA) resin.

At this time, the first component may be prepared by melting the amorphous PHA resin chips in the first component melting unit (10 in FIG. 3) for spinning, and the second component may be prepared by melting the PLA resin chips for spinning with the second component. It is possible to prepare each molten resin by melting in the unit (20 in FIG. 3).

In addition, the mixing process of the first step may be performed in the mixing unit (30 in FIG. 3), and the mixing process may be performed at 170 to 250 ° C for 1 to 20 minutes, preferably at 190 to 230 ° C. It can be done for 5 to 15 minutes.

In addition, the mixture may include the first component and the second component in a weight ratio of 1:2.33 to 1:9.0, preferably in a weight ratio of 1:3.00 to 1:5.67.

If the second component is included in a weight ratio of less than 2.33, as the strength of the biodegradable fiber decreases, the shape of the fiber may not be properly formed or maintained, and spinnability may be poor, and the amount of the second component used When the weight ratio exceeds 9.0, brittle characteristics are expressed as the modulus (Modulus) value of the biodegradable fiber excessively increases, and accordingly, a problem of fiber breakage may occur.

Next, the two-step spinning process may be performed in the spinning unit (50 in FIG. 3) at 210 to 260 °C, preferably at 225 to 250 °C. At this time, when the spinning process is performed at less than 210 ° C., there may be a problem in that the spinnability of the mixture is poor, and when the spinning process is performed at a temperature exceeding 260 ° C., the polylactic acid resin in the mixture is thermally decomposed and carbonized. Due to this, there may be a problem that the physical properties of the manufactured biodegradable fiber are poor and the value as a product is also lowered.

In addition, the two-step spinning process may be performed at a spinning speed of 1,000 to 6,000 mpm (meters per minute), preferably at a spinning speed of 1,000 to 5,500 mpm, more preferably at a spinning speed of 1,000 to 2,000 It can be done at a spinning speed of mpm. At this time, when the spinning speed is less than 1,000 mpm or more than 6,000 mpm, the spinning draft value and the fineness of the manufactured fiber cannot be kept constant, so there may be a problem in that the fiber is not properly formed.

Next, after the spinning process and before the stretching process, a cooling process (40 in FIG. 3) and an emulsion process may be further performed. At this time, if the cooling process is a process of cooling to post-process the spinning material that is spun to form a high temperature, a known method can be used without limitation, and the emulsion process applies an oil agent through an oil agent guide and rubs the fibers. Since any method of imparting a reducing characteristic can be used without limitation, a description thereof will be omitted in the present invention.

Next, the two-step stretching and heat setting process can be performed through a first godet roller (60 in FIG. 3) and a second godet roller (70 in FIG. 3), and the temperature and speed of heat setting and stretching are It can be used without limitation according to the purpose, so it is omitted.

Next, the biodegradable fiber manufacturing method of the present invention may further perform a winding process of winding the obtained biodegradable fiber after performing the stretching and heat setting processes.

At this time, the winding process can be performed in the winding unit (80 in FIG. 3), and winding process conditions such as winding speed can be performed by appropriately adjusting well-known conditions, so they will be omitted.

Hereinafter, the present invention will be described through the following examples. At this time, the following examples are only presented to illustrate the invention, and the scope of the present invention is not limited by the following examples.

[Example]

Preparation Example 1: Preparation of First Component

As a first component, an amorphous polyhydroxy alkanoates (PHA) resin was prepared.

At this time, the amorphous PHA resin is a copolymer containing 50 mol% of a repeating unit represented by the following formula 1-1 and 50 mol% of a repeating unit represented by the following formula 2-1, It is a copolymer.

[Formula 1-1]

[Formula 2-1]

[Formula 3-1]

In Formulas 1-1, 2-1 and 3-1, R ₁ is an n-propylene group, R ₂ is a methyl group, R ₃ is a methylene group, n in Formula 1-1 is 1, and Formula 2- m of 1 is 1, the molar ratio of n and m in Formula 3-1, m/n = 1, and l is an integer that satisfies the weight average molecular weight of the copolymer of 298,000 to 302,000.

Preparation Example 2 to Preparation Example 3: First Component

A first component was prepared in the same manner as in Example 1, but the formulas 3-2 to 3-3 containing 25 mol% and 55 mol% of the repeating units represented by Formula 1-1 in the amorphous PHA resin, respectively. Each of the indicated copolymers was prepared, and Preparation Examples 2 to 3 were performed as shown in Table 1 below.

Comparative Preparation Example 1 ~ Comparative Preparation Example 2: First Component

In the same manner as in Example 1, the first component was prepared, but in the amorphous PHA resin, Formulas 3-4 to 3-5 containing 15 mol% and 70 mol% of the repeating unit represented by Formula 1-1, respectively. Each of the indicated copolymers was prepared and Comparative Preparation Example 1 to Comparative Preparation Example 2 were performed as shown in Table 1 below.

division Formula 3 R _{1 R2 R3} m/n copolymer
weight average molecular weight Preparation Example 1 Formula 3-1 n-propylene group methyl group methylene group One 298,000 ~ 302,000 Preparation example 2 Formula 3-2 3 347,000 ~ 352,000 Preparation Example 3 Formula 3-3 0.82 268,000 ~ 272,000 Comparative preparation example 1 Formula 3-4 5.67 400,000 ~ 405,000 Comparative preparation example 2 Formula 3-5 0.43 245,000 ~ 250,000

Example 1: Preparation of biodegradable fibers with excellent flexibility

The first component (10 in FIG. 3) and the second component (20 in FIG. 3) were added at a weight ratio of 1:4.0 and kept at 240° C. for 10 minutes. A mixture (30 in FIG. 3) was prepared by mixing.

At this time, the first component was used by melting the amorphous PHA resin chips of Preparation Example 1, and the second component was used by melting polylactic acid (PLA) resin chips.

Next, the mixture was spun at a speed of 1,500 mpm (meters per minute) under 240 ° C, cooled and solidified at 60 ° C for 30 minutes, and then 80 and 120 through the first and second godet rollers, respectively. Biodegradable fibers were prepared by drawing at a speed of 1000 mpm under ℃ and then heat-setting.

Experimental Example 1: Observation of biodegradable fibers

The biodegradable fibers prepared in Example 1 were observed through SEM, and the results are shown in FIG.

Referring to FIG. 1, it was found that in Example 1, the two components were uniformly mixed and had appropriate strength to maintain the shape of the fiber well.

Examples 2 to 7: Preparation of biodegradable fibers with excellent flexibility

Biodegradable fibers were prepared in the same manner as in Example 1, but Examples 2 to 7 were performed under the conditions of Tables 2 to 4 below.

Comparative Example 1: Preparation of PET fibers

PET fibers were prepared in the same manner as in Example 1, but using a polyethylene terephthalate (PET) resin instead of the first component and the second component.

At this time, the spinning process was performed at a speed of 1,500 mpm under 300 ℃.

Comparative Examples 2 to 9: Preparation of biodegradable fibers

Biodegradable fibers were prepared in the same manner as in Example 1, but Comparative Examples 2 to 9 were performed under the conditions of Tables 4 to 6 below.

Experimental Example 2: Evaluation of physical properties of biodegradable fibers

The biodegradable fibers prepared in Examples 1 to 9 and Comparative Examples 1 to 9 were evaluated in the following manner and are shown in Tables 2 to 6 below.

(1) Measurement of strength and elongation

It was measured using an automatic tensile tester (Textechno) at a speed of 200 cm/min and a gripping distance of 50 cm. Strength and elongation are the value (g/de) obtained by dividing the load applied to the biodegradable fiber by denier when it is stretched until it is cut by applying a certain force to the biodegradable fiber. defined as

(2) Measurement of flexibility (modulus slope)

In the measurement of flexibility (Modulus), the X-axis was measured by measuring the length of the fiber from the results of the automatic tensile tester, and a modulus graph was drawn with the Y-axis by measuring the tensile strength of the fiber, and its slope was measured.

At this time, when the slope value of the modulus graph was less than 0.45, the softness of the fiber was evaluated as too high, and when it exceeded 0.55, the flexibility was evaluated as insufficient.

(3) Radioactivity evaluation

Radioactivity was marked with "◎" when there was no fiber breakage during spinning and winding was successful, "○" was marked when there was no fiber breakage and winding was cut once an hour, and no fiber breakage and winding was 1. If it breaks twice in an hour, it is marked as "Δ", and if there is no breakage of the fiber and winding is cut three times in one hour, it is marked as "x".

division Example 1 Example 2 Example 3 Example 4 manufacturing
method 1st ingredient Preparation example 1 Preparation example 2 Preparation example 3 Preparation example 1 Second Component PLA resin PLA resin PLA resin PLA resin 1st component: 2nd component weight ratio 1:4.0
(20:80) 1:4.0
(20:80) 1:4.0
(20:80) 1:2.33 (30:70) spinning process Temperature (℃) 260 260 260 260 speed (mpm) 1,500 1,500 1,500 1,500 fiber Fineness (de) 1.9 1.9 1.9 1.9 number of filaments 48 48 48 48 Intensity (g/de) 3.73 3.79 3.54 3.52 Confidence (%) 31.1 30.3 32.4 31.2 Modulus slope 0.58 0.63 0.47 0.53 radioactive ◎ ○ ○ △

division Example 5 Example 6 Example 7 manufacturing
method 1st ingredient Preparation example 1 Preparation example 1 Preparation example 1 Second Component PLA resin PLA resin PLA resin 1st component: 2nd component weight ratio 1:9.0
(10:90) 1:4.0
(20:80) 1:4.0
(20:80) spinning process Temperature (℃) 260 225 250 speed (mpm) 1,500 1,500 1,500 fiber Fineness (de) 1.9 1.9 1.9 number of filaments 48 48 48 Intensity (g/de) 3.98 3.70 3.73 Confidence (%) 29.1 30.4 31.3 Modulus slope 0.68 0.59 0.56 radioactive ◎ ◎ ◎

division Comparative Example 1 Comparative Example 2 Comparative Example 3 manufacturing
method 1st ingredient PET
100% by weight - comparison
Preparation example 1 Second Component PLA resin PLA resin 1st component: 2nd component weight ratio - 1:4.0 spinning process Temperature (℃) 260 260 speed (mpm) 1,500 1,500 fiber Fineness (de) 2.1 2.1 1.9 number of filaments 48 48 48 Intensity (g/de) 3.97 3.98 3.86 Confidence (%) 30.6 29.1 28.5 Modulus slope 0.75 0.72 0.76 radioactive ◎ ◎ ○

division Comparative Example 4 Comparative Example 5 Comparative Example 6 Comparative Example 7 manufacturing
method 1st ingredient comparison
Preparation example 2 Preparation example 1 Preparation example 1 Preparation example 1 Second Component PLA resin PLA resin PLA resin PLA resin 1st component: 2nd component weight ratio 1:4.0 1:1.5 (40:60) 1:10.0 1:4.0 spinning process Temperature (℃) 260 260 260 200 speed (mpm) 1,500 1,500 1,500 1,500 fiber Fineness (de) 1.9 1.9 1.9 1.9 number of filaments 48 48 48 48 Intensity (g/de) 3.23 3.62 3.95 3.69 Confidence (%) 35.1 30.2 29.5 30.7 Modulus slope 0.41 0.50 0.72 0.59 radioactive ○ × ◎ ×

division Comparative Example 8 Comparative Example 9 manufacturing
method 1st ingredient Preparation example 1 Preparation example 1 Second Component PLA resin PLA resin 1st component: 2nd component weight ratio 1:4.0 1:4.0 spinning process Temperature (℃) 270 260 speed (mpm) 1,500 7,000 fiber Fineness (de) 1.9 measurement
not allowed number of filaments 48 Intensity (g/de) measurement
not allowed Confidence (%) Modulus slope radioactive △ ×

Looking at the physical property measurement results in Tables 2 to 6, it was confirmed that the biodegradable fibers prepared in Examples 1 to 7 had excellent strength and elongation and excellent flexibility.

On the other hand, in the case of Comparative Example 2 using only the PLA resin, it was confirmed that the modulus slope was very high at 0.72 and the flexibility was insufficient.

In addition, in the case of the fiber of Comparative Example 3 prepared using Comparative Preparation Example 1 in which the mole% of the repeating unit of Formula 1 is less than 20 mole% as the first component, compared to Example 2 (using Preparation Example 2), the strength is excellent However, the modulus slope was rapidly increased, which means that the flexibility was greatly reduced.

In addition, in the case of the fiber of Comparative Example 4 prepared using Comparative Preparation Example 2 in which the mole% of the repeating unit of Chemical Formula 1 as the first component exceeds 60 mole%, when compared to Example 3 (using Preparation Example 3), flexibility was good, but the strength rapidly dropped.

In the case of Comparative Example 5 using 40% by weight of more than 30% by weight of amorphous PHA resin, the spinning fiber breakage problem occurred, compared to Example 1 (20% by weight) and Example 4 (30% by weight). This gave very poor results.

In addition, in the case of Comparative Example 6 using less than 10% by weight of the amorphous PHA resin, the flexibility of the fiber was poor, and the fiber of Comparative Example 2 prepared with only the PLA resin had substantially similar physical properties.

And, in the case of Comparative Example 7 performed at a spinning temperature of less than 210 ° C. at 200 ° C., there was a problem in that the spinnability was very poor and the defect rate was very high.

In addition, in the case of Comparative Example 8 in which spinning was performed at a spinning temperature of 270 ° C., a problem in that some fibers were carbonized due to the PLA resin as the second component, so the measurement of physical properties of the manufactured fibers was meaningless.

And, in the case of Comparative Example 9, which was performed under a spinning speed of 7,000 mpm during spinning, there was a problem in that the fineness of the fiber was spun non-uniformly and the shape of the fiber was not constant.

In the above, the present invention has been described with a focus on embodiments, but this is only an example and does not limit the embodiments of the present invention, and those skilled in the art to which the embodiments of the present invention belong will appreciate the essential characteristics of the present invention. It will be appreciated that various modifications and applications not exemplified above are possible within a range that does not deviate. For example, each component specifically shown in the embodiment of the present invention can be modified and implemented. And differences related to these modifications and applications should be construed as being included in the scope of the present invention as defined in the appended claims.

10: first component melting part 20: second component melting part
30: mixing unit 40: cooling unit
50: radiation part 60: first godet roller
70: second godet roller 80: winding unit

Claims (10)

10 to 30% by weight of an amorphous polyhydroxy alkanoates (PHA) resin; And the remaining amount of polylactic acid (Polylactic acid, PLA) resin; a biodegradable fiber with excellent flexibility.
According to claim 1,
The amorphous polyhydroxy alkanoate resin is a biodegradable fiber with excellent flexibility, characterized in that it contains 20 to 60 mol% of a repeating unit represented by the following formula (1):
[Formula 1]

In Formula 1, R ₁ is a straight-chain alkylene group having 1 to 5 carbon atoms, and n is a natural number of 1 to 3.
According to claim 2,
The amorphous polyhydroxy alkanoate resin is a biodegradable fiber with excellent flexibility, characterized in that it further comprises a repeating unit represented by the following formula (2):
[Formula 2]

In Formula 2, R ₂ is a hydrogen atom or a straight-chain alkyl group having 1 to 15 carbon atoms, R ₃ is a straight-chain alkylene group having 1 to 5 carbon atoms, and m is a natural number of 1 to 3.
The biodegradable fiber with excellent flexibility according to claim 1, wherein the amorphous polyhydroxy alkanoate resin comprises a copolymer represented by the following formula (3):
[Formula 3]

In Formula 3, R ₁ is a straight-chain alkylene group having 1 to 5 carbon atoms, R ₂ is a hydrogen atom or a straight-chain alkyl group having 1 to 15 carbon atoms, R ₃ is a straight-chain alkylene group having 1 to 5 carbon atoms, n and m is a molar ratio, m/n is an integer that satisfies 0.67 to 4.00, and l is an integer that satisfies a weight average molecular weight of 100,000 to 400,000 of the copolymer.
The method of claim 1, wherein the biodegradable fiber,
The slope value of the modulus graph (Y/X) for the fiber length (X) and the tensile strength (Y) of the fiber measured by applying a speed of 200 cm/min and a gripping distance of 50 cm through an automatic tensile tester was 0.45 to 0.68 A biodegradable fiber with excellent flexibility, characterized in that.
According to claim 1,
The biodegradable fiber is a biodegradable fiber with excellent flexibility, characterized in that the fineness of 1.0 ~ 3.0de (denier) and the number of filaments 30 ~ 80 fila.
preparing a mixture by mixing a first component and a second component comprising an amorphous polyhydroxy alkanoate resin; and
Method for producing a biodegradable fiber having excellent flexibility, comprising: obtaining a biodegradable fiber by sequentially performing a spinning process, a stretching process, and a heat setting process on the mixture.
According to claim 7,
The second component is a method for producing a biodegradable fiber having excellent flexibility, characterized in that it comprises a polylactic acid resin.
According to claim 7,
The mixture is a method for producing a biodegradable fiber having excellent flexibility, characterized in that it comprises the first component and the second component in a weight ratio of 1: 2.33 to 9.0.
According to claim 7,
The spinning process is a method for producing a biodegradable fiber with excellent flexibility, characterized in that carried out at a rate of 1,000 to 6,000 mpm (meters per minute) under 210 ~ 260 ℃.

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