KR102585195B1 - Biodegradable fiber having with excellent softness and Method for manufacturing the same - Google Patents

Abstract

The present invention maintains the fiber shape by maintaining appropriate strength by spinning a mixture of amorphous polyhydroxy alkanoates (PHA) resin and polylactic acid (PLA) resin, while reducing brittleness. It relates to a biodegradable fiber with excellent flexibility and excellent biodegradability in the ocean, and a method for manufacturing the same.

Description

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

The present invention relates to a biodegradable fiber with excellent flexibility and a method of manufacturing the same.

Conventionally, synthetic fibers such as polyester, polyolefin, and polyamide have been used as fibers used in household materials, agricultural materials, fishing materials, civil engineering materials, and industrial materials. However, these fibers do not decompose when left in the natural world after use, which causes 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 and landfill have been highlighted. Accordingly, in recent years, there has been a need to reduce the burden on the environment from the perspective of global environmental conservation, and in particular, research on biodegradable materials that do not cause environmental problems by decomposing in soil, water, or air after use is required.

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

As an example of the research on biodegradable polymers, biodegradable polyester fibers were manufactured using succinic acid, an aliphatic polyester. However, in this case, there is a problem that the degree of biodegradation is small because it contains a trace amount of biodegradable components.

Among biodegradable polymers, polylactic acid is an aliphatic polyester polymer that can be manufactured from natural products using lactic acid or lactide as a raw material. Therefore, it is not a simple biodegradable polymer, but is easily hydrolyzed in the presence of water and is disposed of. Since it is later decomposed without polluting the environment, it is used as a general-purpose polymer with a low environmental load.

Meanwhile, polyhydroxyalkanoate (PHA) can be produced by chemical synthesis or by 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 P4HB (Poly(4-hydrobutyrate)), PHV (Poly(5-hydroxyvalerate)), PHH (Poly(3-hydroxyhexanoate)), and PHO (Poly(polyhydroxyoctanoate)).

The biosynthesis of PHA is generally caused by specific deficiency conditions (e.g. lack of macro elements such as phosphorus, nitrogen, trace elements, or oxygen deficiency) and excessive carbon sources, etc., and produces various forms of hydroxyalkanoate within the cell. As polymerization progresses, the polymer physical properties change accordingly.

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

The present invention to solve the above problems has an appropriate strength by mixing and spinning amorphous polyhydroxy alkanoates (PHA) resin and polylactic acid resin, while forming and maintaining the shape of the fiber. The aim is to improve the flexibility of existing biodegradable fibers with strong brittleness and to provide highly flexible biodegradable fibers that are easily biodegradable in the ocean and a manufacturing method thereof.

The biodegradable fiber with excellent flexibility of the present invention to solve the above problems includes 10 to 30% by weight of amorphous polyhydroxy alkanoate resin; and a remaining amount of polylactic acid (PLA) resin.

As a preferred embodiment of the present invention, the amorphous polyhydroxy alkanoate resin may include a repeating unit represented by the following formula (1).

As a preferred embodiment of the present invention, the amorphous polyhydroxy alkanoate resin may contain 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.

As a preferred embodiment of the present invention, the amorphous polyhydroxy alkanoate resin may further include 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.

As a preferred embodiment of the present invention, the amorphous polyhydroxy alkanoate (PHA) resin may include 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 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, 100,000 to 400,000.

As a preferred embodiment of the present invention, the biodegradable fiber has a fiber length ( 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 purpose of the present invention, a method for producing biodegradable fibers with excellent flexibility includes preparing a mixture by mixing a first component and a second component including an amorphous polyhydroxy alkanoate resin; And it may include the step of sequentially performing a spinning process, a stretching process, and a heat setting process on the mixture to obtain a biodegradable fiber.

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

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

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

The biodegradable fiber of the present invention is easily decomposed in the ocean, has excellent flexibility, and has excellent mechanical properties.

Figure 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 manufacturing biodegradable fiber according to an embodiment of the present invention;
Figure 3 is a schematic diagram of a device used in manufacturing biodegradable fiber according to an embodiment of the present invention.

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

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 depending on the content of the repeating structure.

[Formula 1]

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

In detail, first, the crystallized PHA resin refers to a case where the PHA resin does not contain a repeating unit represented by the formula 1, and the semi-crystalline PHA resin has the formula 1 This refers to the case where the indicated repeating unit is included at 5 to 15 mol% in the PHA resin, and the amorphous PHA resin contains the repeating unit represented by Formula 1 at 20 to 60 mol% in the PHA resin. It 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. It can achieve both excellent flexibility and high biodegradability in the ocean.

Hereinafter, the biodegradable fiber with 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 a remaining amount of polylactic acid (PLA) resin.

When explaining each component of 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. It can be included as a %.

If the amorphous PHA resin is included in less than 10% by weight of the total weight of the biodegradable fiber, not only may the fiber lack flexibility, but the fineness of the fiber cannot be maintained at a constant level, leading to the problem 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 may occur when the amorphous PHA resin and polylactic acid (PLA) resin are composite spun, and winding may not be performed properly. Problems such as these may occur.

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

At this time, if the repeating unit represented by Formula 1 is less than 20 mol%, the PHA resin may have semi-crystalline characteristics and there may be a problem of deterioration in flexibility properties, and if it contains more than 60 mol%, the amorphous PHA resin When composite spinning 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 containing a repeating unit represented by the following Formula 2 in mole percent, excluding the repeating unit represented by the Formula 1.

[Formula 2]

In Formula 2, R ₂ may be hydrogen or a straight-chain alkyl group with 1 to 15 carbon atoms, preferably hydrogen or a straight-chain alkyl group with 1 to 10 carbon atoms, more preferably hydrogen or a straight-chain alkyl group with 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 between 1 and 2.

Additionally, the amorphous PHA resin containing repeating units represented by Formula 1 and Formula 2 described above may include a copolymer represented by Formula 3 below.

[Formula 3]

In Formula 3, l may be an integer that satisfies the weight average molecular weight of the copolymer from 100,000 to 400,000, preferably the weight average molecular weight of the copolymer from 150,000 to 380,000, and more preferably the weight average molecular weight of the copolymer. It may be an integer satisfying 260,000 to 360,000. In addition, R ₁ , R ₂ and R ₃ are the same as those described in Formulas 1 and 2 above, so they will be omitted. However, n and m in Formula 3 are molar ratios, and 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 contain the remaining amount of polylactic acid (PLA) resin out of 100% by weight excluding the amorphous PHA resin. At this time, the polylactic acid resin plays a role in securing the strength of the fiber, so the more polylactic acid contained in the fiber, the higher the modulus value of the fiber is, but the brittle characteristics also become stronger, so it becomes rubber-like. It is desirable to improve the flexibility of the fiber by mixing and spinning it with the amorphous PHA resin, which has properties like the above.

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

The biodegradable fiber of the present invention is a modulus graph (Y/X) for fiber length ( The slope (△Y/△X) value may be 0.45 to 0.68, and 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 deterioration of the strength of the fiber, and if it exceeds 0.68, the fiber may have good strength, but its flexibility is greatly reduced and there may be a problem of it becoming too brittle.

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

Additionally, the biodegradable fiber may have a filament number of 30 to 80 fila, preferably 35 to 75 fila.

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, as schematically shown in FIG. 3; and a second step of sequentially performing a spinning process, a stretching process, and a heat setting process on the mixture to obtain a biodegradable fiber.

In the manufacturing method described later, parts that overlap with those described in the biodegradable fiber described above will be omitted and explained.

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

At this time, the first component can be prepared by melting an amorphous PHA resin chip in the first component melting section (10 in Figure 3) for spinning, and the second component can be prepared by melting a PLA resin chip for spinning. Each molten resin can be prepared by melting in the unit (20 in FIG. 3).

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

Additionally, the mixture may include the first component and the second component in a weight ratio of 1:2.33 to 1:9.0, and 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, the strength of the biodegradable fiber decreases, the shape of the fiber may not be formed or maintained properly, there may be a problem of poor spinability, and the amount of second component used If the weight ratio exceeds 9.0, the modulus value of the biodegradable fiber increases excessively, resulting in brittleness, which may cause fiber fracture.

Next, the spinning process in step 2 can be performed at 210 to 260°C in the spinning unit (50 in FIG. 3), and preferably at 225 to 250°C. At this time, if the spinning process is performed below 210 ℃, there may be a problem that the spinnability of the mixture becomes poor, and if performed at a temperature exceeding 260 ℃, a problem occurs in which the polylactic acid resin in the mixture is thermally decomposed and carbonized, which causes As a result, there may be a problem in that the physical properties of the manufactured biodegradable fiber become poor and the value as a product decreases.

Additionally, the two-stage spinning process can 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, and more preferably at a spinning speed of 1,000 to 2,000 mpm. It can be performed at a spinning speed of mpm. At this time, if 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, which may lead to a problem in which the fiber is not formed properly.

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, in the cooling process, any known method can be used without limitation as long as it is a process of cooling the spinning material, which forms a high temperature, for post-processing. The emulsion process applies an emulsion through an emulsion guide and causes friction to the fiber. Any method that provides reducing properties can be used without limitation, so description thereof will be omitted in the present invention.

Next, the two-step stretching and heat setting process can be performed through the first godet roller (60 in Figure 3) and the second godet roller (70 in Figure 3), and the temperature and speed of heat setting and stretching are It can be used without restrictions depending on the purpose, so it should be 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 known conditions, so they are omitted.

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

[Example]

Preparation Example 1: Preparation of the first component

Amorphous polyhydroxy alkanoates (PHA) resin was prepared as the first ingredient.

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, and is represented by the following formula 3-1 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 in 1 is 1, the n and m molar ratio of Chemical Formula 3-1 is 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 ~ Preparation Example 3: First ingredient

The first component was prepared in the same manner as in Example 1, except that the amorphous PHA resin was prepared by formulas 3-2 to 3-3 containing 25 mol% and 55 mol% of the repeating unit represented by formula 1-1, 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 ingredient

The first component was prepared in the same manner as in Example 1, except that the amorphous PHA resin was prepared by 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 R ₂ R ₃ 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 Comparison preparation example 1 Formula 3-4 5.67 400,000 ~ 405,000 Comparison preparation example 2 Formula 3-5 0.43 245,000 ~ 250,000

Example 1: Preparation of biodegradable fiber with excellent flexibility

The first component (10 in Figure 3) and the second ingredient (20 in Figure 3) were added at a weight ratio of 1:4.0 and incubated 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 chip of Preparation Example 1, and the second component was used by melting the polylactic acid (PLA) resin chip.

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

Experimental Example 1: Observation of biodegradable fiber

The biodegradable fiber prepared in Example 1 was observed through SEM, and the results are shown in Figure 1.

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

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

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

Comparative Example 1: Preparation of PET fiber

PET fibers were manufactured in the same manner as in Example 1, except that polyethylene terephthalate (PET) resin was used instead of the first and second components.

At this time, the spinning process was performed at 300°C at a rate of 1,500 mpm.

Comparative Example 2 to Comparative Example 9: Production of biodegradable fiber

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

Experimental Example 2: Evaluation of physical properties of biodegradable fiber

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 calculated by applying a certain force to a biodegradable fiber and stretching it until it is cut. The strength is calculated by dividing the load applied by the denier (g/de), and the elongation is calculated by expressing the initial length as a percentage of the stretched length (%). It was defined as .

(2) Flexibility (Modulus slope) measurement

To measure flexibility, the length of the fiber was measured from the results of an automatic tensile tester, plotted on the

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

(3) Radioactivity evaluation

Spinnability was indicated as "◎" if there was no breakage of the fiber during spinning and the winding was good. It was indicated as "○" if there was no breakage of the fiber and the winding was broken once per hour. If there was no breakage of the fiber and the winding was broken once per hour, it was marked as "○". If it breaks twice in an hour, it is marked as "△", and if there is no breakage of the fiber and the winding breaks three times in an hour, it is marked as "×".

division Example 1 Example 2 Example 3 Example 4 manufacturing
method first ingredient Preparation example 1 Preparation example 2 Preparation example 3 Preparation example 1 2nd ingredient PLA resin PLA resin PLA resin PLA resin First ingredient:second ingredient 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 Strength (g/de) 3.73 3.79 3.54 3.52 Elasticity (%) 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 first ingredient Preparation example 1 Preparation example 1 Preparation example 1 2nd ingredient PLA resin PLA resin PLA resin First ingredient:second ingredient 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 Strength (g/de) 3.98 3.70 3.73 Elasticity (%) 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 first ingredient PET
100% by weight - comparison
Preparation example 1 2nd ingredient PLA resin PLA resin First ingredient:second ingredient 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 Strength (g/de) 3.97 3.98 3.86 Elasticity (%) 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 first ingredient comparison
Preparation example 2 Preparation example 1 Preparation example 1 Preparation example 1 2nd ingredient PLA resin PLA resin PLA resin PLA resin First ingredient:Second ingredient 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 Strength (g/de) 3.23 3.62 3.95 3.69 Elasticity (%) 35.1 30.2 29.5 30.7 Modulus slope 0.41 0.50 0.72 0.59 radioactivity ○ × ◎ ×

division Comparative example 8 Comparative Example 9 manufacturing
method first ingredient Preparation example 1 Preparation example 1 2nd ingredient PLA resin PLA resin First ingredient:Second ingredient 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
Impossible Number of filaments 48 Strength (g/de) measurement
Impossible Elasticity (%) 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 in which only PLA resin was used, the modulus slope was very high at 0.72 and it was confirmed that flexibility was insufficient.

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

In addition, in the case of the fiber of Comparative Example 4 manufactured using Comparative Preparation Example 2 in which the mole% of the repeating unit of Chemical Formula 1 as the first component exceeds 60 mol%, compared to Example 3 (using Preparation Example 3), the flexibility It was good, but the intensity showed a sharp drop.

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

In addition, in the case of Comparative Example 6, in which less than 10% by weight of amorphous PHA resin was used, the flexibility of the fiber was low, and the results showed that the fiber had physical properties in a substantially similar range to the fiber of Comparative Example 2 manufactured with PLA resin alone.

In addition, in the case of Comparative Example 7, which was performed at 200°C, which is less than 210°C, the spinnability was very poor and the defective 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 occurred in which part of the fiber was carbonized due to the PLA resin, which is the second component, and the measurement of the physical properties of the manufactured fiber was meaningless.

In addition, in the case of Comparative Example 9, in which spinning was performed at a spinning speed of 7,000 mpm, there was a problem in that the fibers were spun unevenly and the shape of the fiber was not constant.

Although the present invention has been described above with a focus on embodiments, this is only an example and does not limit the embodiments of the present invention, and those skilled in the art will be able to understand the essential characteristics of the present invention. It can be seen that various modifications and applications not exemplified above are possible without departing from the scope. For example, each component specifically shown in the embodiments of the present invention can be modified and implemented. And these variations and differences in application should be construed as being included in the scope of the present invention as defined in the appended claims.

10: first component melting portion 20: second component melting portion
30: mixing section 40: cooling section
50: Radiating part 60: First godet roller
70: Second godet roller 80: Winding unit

Claims (10)

delete delete delete 10 to 30% by weight of amorphous polyhydroxy alkanoates (PHA) resin; And a remaining amount of polylactic acid (PLA) resin;
The amorphous polyhydroxy alkanoate resin includes a copolymer represented by the following formula (3),
The slope value of the modulus graph (Y/X) for fiber length ( A biodegradable fiber with excellent flexibility, characterized as a fiber that satisfies the following:
[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, and R ₃ is a straight-chain alkylene group having 1 to 5 carbon atoms, m/ n is an integer that satisfies 0.80 to 3.00, and l is an integer that satisfies the weight average molecular weight of 150,000 to 380,000 of the copolymer.
delete According to paragraph 4,
The biodegradable fiber is a biodegradable fiber with excellent flexibility, characterized in that the fineness is 1.0 ~ 3.0de (denier) and the number of filaments is 30 ~ 80 fila.
Preparing a mixture by mixing a first component and a second component containing an amorphous polyhydroxy alkanoate resin at a weight ratio of 1:2.33 to 9.0; and
Performing a process comprising: obtaining biodegradable fibers by sequentially performing a spinning process, a stretching process, and a heat setting process on the mixture,
The first component is an amorphous polyhydroxy alkanoate resin (Polyhydroxy alkanoates, PHA) containing a copolymer represented by the following formula (3),
The second component is polylactic acid (PLA) resin,
The slope of the modulus graph (Y/X) for the fiber length ( A method for producing a biodegradable fiber with excellent flexibility, characterized in that the value satisfies 0.45 to 0.68;
[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, and R ₃ is a straight-chain alkylene group having 1 to 5 carbon atoms, m/ n is an integer that satisfies 0.80 to 3.00, and l is an integer that satisfies the weight average molecular weight of 150,000 to 380,000 of the copolymer.
delete delete In clause 7,
A method for producing a highly flexible biodegradable fiber, characterized in that the spinning process is performed at a rate of 1,000 to 6,000 mpm (meters per minute) at 210 to 260°C.