KR20220025464A - polyester staple fiber, nonwoven fabric including the same and and method for manufacturing thereof - Google Patents

Abstract

The present invention relates to a polyester staple fiber, a non-woven fabric comprising the same, and a method for manufacturing the same. More specifically, the present invention relates to a polyester staple fiber that can effectively suppress a phenomenon in which the degree of molecular orientation is rapidly increased when manufacturing a fiber by spinning a polyester-based resin as the main material, and to a non-woven fabric comprising the same and a method for manufacturing the same.

Description

Polyester staple fiber, nonwoven fabric including same, and manufacturing method thereof

The present invention relates to a polyester staple fiber, a nonwoven fabric comprising the same, and a method for manufacturing the same, and more particularly, to effectively prevent a phenomenon in which the degree of molecular orientation rapidly increases when a fiber is manufactured by spinning a polyester resin as a main subject. It relates to a polyester staple fiber capable of suppressing, a nonwoven fabric comprising the same, and a method for manufacturing the same.

In the process of producing a polyester-based fiber, while suppressing the degree of molecular orientation, many studies have been conducted on a method of spinning and manufacturing a polyester partially oriented yarn.

As a method of producing polyester fibers while suppressing the degree of molecular orientation, the methods known so far are the first method through modification of the raw material polymer (copolymerization, molecular chain crosslinking, etc.), and the second method is a polymer material It can be roughly divided into a method of mixing.

As a first method, U.S. Patent No. 4,518,744 proposes a method of adding pentaerythrite, trimethylopropane, mellitic acid, and trimellitic acid, which are compounds having a branch in the molecular chain, before transesterification or polymerization reaction. In addition, U.S. Patent No. 4,966,740 proposes a method of adding tetraethyl silicate before transesterification or polymerization, and U.S. Patent No. 4,092,299 proposes a molecular chain crosslinking method using a tetrafunctional material. However, these first methods have a problem in that polymerization conditions must be specially selected, and workability in the stretching process is deteriorated.

As a second method, U.S. Patent No. 4,609,710 discloses a method of mixing polystyrene, polyamide, polymethyl methacrylate, etc. as a molecular orientation control agent during or after the polyester polymerization reaction. In the case of conventional polyester polymerization, a small amount ['Orientation Supression in Fibers Spun from Polymer Melt Blends' (H. Brody, J of Appl. Polym. Sci., 31, 2753 1986)]. However, in such a case, the flowability of the polymer melt in the spinning process is rapidly changed, which greatly affects the spinning characteristics, especially the spinning speed, and thus lowers the spinning orientation. However, the method has difficulties in stable spinning due to the problem of uniformly mixing the added polymer.

The present invention has been devised to solve the above problems, and a polyester staple fiber capable of effectively suppressing a phenomenon in which the degree of molecular orientation rapidly increases when a fiber is manufactured by spinning a polyester resin as a main subject, it An object of the present invention is to provide a nonwoven fabric comprising the same and a method for manufacturing the same.

Another object of the present invention is to provide a polyester staple fiber having fine fineness, a nonwoven fabric including the same, and a method for manufacturing the same.

In order to solve the above problems, the polyester-based staple fiber of the present invention is a polyester-based staple fiber produced by spinning a composition for fiber formation, and the fiber-forming composition may include a polyester-based resin and an orientation inhibitor. .

In a preferred embodiment of the present invention, the polyester staple fiber of the present invention may satisfy the following condition (1).

(1) 20℃ ≤ B - A

In the above condition (1), A is the glass transition temperature (Tg) of the polyester-based resin, B is the glass transition temperature (Tg) of the orientation inhibitor.

In a preferred embodiment of the present invention, the polyester staple fiber of the present invention may have a fineness of 0.6 denier or less.

In a preferred embodiment of the present invention, the polyester staple fiber of the present invention may have a fiber length of 20 to 70 mm.

In a preferred embodiment of the present invention, the polyester staple fiber of the present invention may satisfy the following condition (2).

(2) 15% ≤ C ≤ 28%

In the above condition (2), C represents the elongation at break of the polyester staple fiber.

In a preferred embodiment of the present invention, the polyester-based resin may have a glass transition temperature (Tg) of 60 ~ 100 ℃.

In a preferred embodiment of the present invention, the orientation inhibitory agent may have a glass transition temperature (Tg) of 100 ~ 140 ℃.

In a preferred embodiment of the present invention, the orientation inhibitor may include at least one selected from a polymethyl methacrylate-based resin, a polystyrene-based resin, and a methyl methacrylate-styrene-based copolymer resin.

In a preferred embodiment of the present invention, the orientation inhibitor may include a compound represented by the following formula (1).

[Formula 1]

In Formula 1, R ₁ , R ₂ , R ₃ and R ₄ are each independently a hydrogen atom or a C1-C5 alkyl group, and n is a rational number satisfying a weight average molecular weight of 100,000 to 300,000.

In a preferred embodiment of the present invention, the composition for forming fibers may include an orientation inhibitor in an amount of 0.1 to 3.0% by weight based on the total weight%.

In a preferred embodiment of the present invention, the polyester-based resin may include at least one selected from a polyethylene terephthalate (PET) resin, a polybutylene terephthalate (PBT) resin, and a polytrimethylene terephthalate resin.

In a preferred embodiment of the present invention, the polyester-based resin may have an intrinsic viscosity (I.V) of 0.55 to 0.75 dl/g.

On the other hand, the nonwoven fabric of the present invention includes the polyester staple fiber of the present invention as mentioned above.

In a preferred embodiment of the present invention, the non-woven fabric of the present invention may be a dry-laid non-woven fabric, a wet-laid non-woven fabric or an air-laid non-woven fabric.

Furthermore, the method for producing a polyester-based staple fiber of the present invention includes a first step of preparing a polyester-based resin chip and an orientation inhibitor chip, respectively, and spinning a fiber-forming composition in which the polyester-based resin chip and the orientation inhibitor chip are melted A second step of manufacturing an unstretched sub-tow by cooling after inputting and spinning into a spinneret, a third step of stretching the undrawn sub-tow, and heat-setting and cutting the stretched sub-tow Thus, it may include a fourth step of manufacturing the polyester staple fiber.

In a preferred embodiment of the present invention, the method for producing a polyester staple fiber of the present invention may satisfy the following condition (1).

(1) 20℃ ≤ B - A

In the above condition (1), A is the glass transition temperature (Tg) of the polyester-based resin chip, B is the glass transition temperature (Tg) of the orientation inhibitor chip.

In a preferred embodiment of the present invention, the polyester staple fiber prepared by the method for producing the polyester staple fiber of the present invention may have a fineness of 0.6 denier or less.

In a preferred embodiment of the present invention, the polyester staple fiber produced by the method for producing the polyester staple fiber of the present invention may have a fiber length of 20 to 70 mm.

In a preferred embodiment of the present invention, the polyester staple fiber produced by the method for producing the polyester staple fiber of the present invention may satisfy the following condition (2).

(2) 15% ≤ C ≤ 28%

In the above condition (2), C represents the elongation at break of the polyester staple fiber.

In a preferred embodiment of the present invention, the orientation inhibitor chip may include a compound represented by the following formula (1).

[Formula 1]

In Formula 1, R ₁ , R ₂ , R ₃ and R ₄ are each independently a hydrogen atom or a C1-C5 alkyl group, and n is a rational number satisfying a weight average molecular weight of 100,000 to 300,000.

In a preferred embodiment of the present invention, the composition for fiber formation of the method for producing a polyester staple fiber of the present invention may contain 0.1 to 3.0 wt% of the molten orientation inhibitor chip based on the total weight%.

In a preferred embodiment of the present invention, the undrawn subtow may have a fineness of 3.0 denier or less.

In a preferred embodiment of the present invention, the unstretched subtow may satisfy the following condition (3).

(3) 320% ≤ D ≤ 600%

In the above condition (3), D represents the elongation at break of the unstretched sub tow.

In a preferred embodiment of the present invention, stretching may be performed at a stretching ratio of 3.5 to 4.5 times.

On the other hand, the manufacturing method of the nonwoven fabric of the present invention comprises the above-mentioned first step of manufacturing a nonwoven web by carding the polyester staple fiber of the present invention, and a second step of manufacturing a nonwoven fabric by heat treating the nonwoven web. may include

Hereinafter, the terms used in the present invention will be described.

In the present invention, the term 'fiber' used herein means 'yarn' or 'thread', and refers to various types of conventional yarns and fibers.

The polyester staple fiber of the present invention, a nonwoven fabric comprising the same, and a method for manufacturing the same can effectively suppress a phenomenon in which the degree of molecular orientation is rapidly increased when the fiber is manufactured by spinning a polyester resin as a main subject.

In addition, the polyester staple fiber of the present invention, a nonwoven fabric comprising the same, and a method for manufacturing the same increase the breaking elongation of the undrawn subtow, thereby increasing the draw ratio in subsequent drawing as well as polyester with low fineness It is possible to manufacture staple fibers based on

Hereinafter, with reference to the accompanying drawings, embodiments of the present invention will be described in detail so that those of ordinary skill in the art can easily carry out the present invention. The present invention may be embodied in many different forms and is not limited to the embodiments described herein. In order to clearly explain the present invention in the drawings, parts irrelevant to the description are omitted, and the same reference numerals are added to the same or similar elements throughout the specification.

The polyester staple fiber of the present invention is prepared by spinning a composition for forming fibers.

The composition for fiber formation of the present invention may include a polyester-based resin and an orientation inhibitor, through which spinning and stretching due to the attractive force between the aromatic ring included in the orientation inhibitor and the aromatic ring included in the polyester-based resin molecule It is possible to more effectively inhibit the orientation crystallization that occurs during the process. It is a well-known fact that the aromatic ring is composed of a double bond between constituent carbon atoms, and thus an attraction force exists with the adjacent aromatic ring.

In addition, the composition for fiber formation of the present invention may satisfy the following condition (1).

(1) 20 °C ≤ B - A, preferably 20 °C ≤ B - A ≤ 60 °C, more preferably 30 °C ≤ B - A ≤ 50 °C, even more preferably 35 °C ≤ B - A ≤ 45 °C

In the above condition (1), A is the glass transition temperature (Tg) of the polyester-based resin, B is the glass transition temperature (Tg) of the orientation inhibitor.

As described above, by satisfying condition (1), the difference in solidification behavior of the polyester-based resin and the orientation inhibitor can be maintained, and the crystal orientation behavior of the polyester-based resin can be suppressed.

In addition, the composition for forming fibers of the present invention may contain 0.1 to 3.0 wt% of the orientation inhibitor, preferably 0.2 to 2.3 wt%, more preferably 0.7 to 1.3 wt%, based on the total weight%, if If the orientation inhibitor is included in an amount exceeding 3.0 wt %, there may be a problem in that the operability in the spinning process is deteriorated.

In addition, the composition for fiber formation of the present invention may include 97.0 to 99.9 wt% of the polyester-based resin, preferably 97.7 to 99.8 wt%, more preferably 98.7 to 99.3 wt%, based on the total weight% .

The polyester-based resin of the present invention may include at least one selected from polyethylene terephthalate (PET) resin, polybutylene terephthalate (PBT) resin, and polytrimethylene terephthalate resin, preferably polyethylene terephthalate ( PET) resin.

In addition, the polyester-based resin of the present invention may have a glass transition temperature (Tg) of 60 ~ 100 ℃, preferably 70 ~ 90 ℃, more preferably 75 ~ 85 ℃, if the glass transition temperature (Tg) If it is less than 60℃, the fiber implemented through the polyester-based resin or the article implemented through them has a large change with time even in summer, for example, a temperature condition exceeding 40℃, and bonding between fibers may occur, resulting in significantly reduced storage stability. There is a concern that there is a risk of causing poor spinning when bonding between chips occurs, and there is a problem that the shrinkage characteristic is excessively expressed after being implemented with fibers or the like. In addition, if the glass transition temperature (Tg) exceeds 100 ℃, there is no difference in the solidification behavior of the polyester-based resin and the orientation inhibitor, and there may be a problem in the manufacture of fineness because the crystal orientation behavior of the polyester-based resin cannot be suppressed. there is.

In addition, the polyester-based resin of the present invention may have an intrinsic viscosity (IV) of 0.55 to 0.75 dl/g, preferably 0.60 to 0.70 dl/g, more preferably 0.62 to 0.68 dl/g, and if the intrinsic viscosity If (IV) is less than 0.55 dl/g, the deadening phenomenon during spinning increases significantly, resulting in poor spinning operability, and due to the low viscosity, there is a problem that the yarn breakage may occur when discharging the polymer directly under the detention during spinning, 0.75 dl If /g is exceeded, there may be a problem with radioactivity due to high pack pressure.

The orientation inhibitor of the present invention may include at least one selected from polymethyl methacrylate-based resin, polystyrene-based resin, and methyl methacrylate-styrene-based copolymer resin, and preferably includes polymethyl methacrylate-based resin. and, more preferably, may include a compound represented by the following formula (1).

[Formula 1]

In Formula 1, R ₁ , R ₂ , R ₃ and R ₄ are each independently a hydrogen atom or a C1 to C5 alkyl group, preferably R ₁ and R ₂ are each independently a hydrogen atom or a methyl group, R ₃ and R ₄ may each independently be a C1-C3 alkyl group.

In addition, in Formula 1, n may be a rational number satisfying a weight average molecular weight of 100,000 to 300,000, preferably 120,000 to 250,000, more preferably 150,000 to 200,000, and if the weight average molecular weight is less than 100,000, spinning workability There may be a problem of this deterioration, and if it exceeds 300,000, there may be a problem in that the fineness of the manufactured fiber exceeds 0.6 denier.

In addition, the orientation inhibitor may have a glass transition temperature (Tg) of 100 to 140 ℃, preferably 110 to 130 ℃, more preferably 115 to 125 ℃, if the glass transition temperature (Tg) is less than 100 ℃ Since there is no difference in the solidification behavior of the ester-based resin and the orientation inhibitor, the crystal orientation behavior of the polyester-based resin cannot be suppressed, so there may be a problem in the production of fineness. It may increase and cause problems such as thread breakage.

On the other hand, the polyester staple fiber of the present invention may have a fineness of 0.6 denier or less, preferably 0.4 to 0.6 denier, more preferably 0.45 to 0.55 denier, and if the fineness exceeds 0.6 denier, it functions as a fineness product There may be a problem with this falling.

In addition, the polyester staple fiber of the present invention may have a fiber length of 20 to 70 mm, preferably 25 to 60 mm, more preferably 30 to 50 mm, and if the fiber length is less than 20 mm, the physical properties of the fibers configured in the nonwoven carding process There may be a problem of lowering carding workability and morphological stability of the nonwoven fabric due to insufficient phosphorus bonding, and when it exceeds 70 mm, entanglement of the constituent fibers increases in the nonwoven carding process, and there may be a problem of lowering the surface uniformity of the nonwoven fabric.

In addition, the polyester staple fiber of the present invention may satisfy the following condition (2).

2) 15% ≤ C ≤ 28%, preferably 17% ≤ C ≤ 26%, more preferably 19% ≤ C ≤ 24%

In the above condition (2), C represents the elongation at break of the polyester staple fiber. If C is less than 15%, there may be a problem in that elasticity is lowered, and if it exceeds 28%, there may be a problem in that spinning is poor in the manufacturing process.

Furthermore, the nonwoven fabric of the present invention includes the aforementioned polyester-based staple fibers. In this case, the non-woven fabric of the present invention may be a dry-laid non-woven fabric, a wet-laid non-woven fabric or an air-laid non-woven fabric.

On the other hand, the method for producing a polyester staple fiber of the present invention includes the first to fourth steps.

First, in the first step of the method for producing a polyester-based staple fiber of the present invention, a polyester-based resin chip and an orientation inhibitor chip may be prepared, respectively. At this time, the characteristics, types, etc. of the polyester-based resin chip are the same as those of the polyester-based resin described above, and are made into chips, and the characteristics, types, etc. of the orientation inhibitor chip are the same as those of the orientation inhibitor described above, It is chipped.

In addition, the polyester-based resin chip and the orientation inhibitor chip prepared in the first step may satisfy the following condition (1).

(1) 20 °C ≤ B - A, preferably 20 °C ≤ B - A ≤ 60 °C, more preferably 30 °C ≤ B - A ≤ 50 °C, even more preferably 35 °C ≤ B - A ≤ 45 °C

In the above condition (1), A is the glass transition temperature (Tg) of the polyester-based resin, B is the glass transition temperature (Tg) of the orientation inhibitor.

The polyester-based resin chip of the present invention may include at least one selected from a polyethylene terephthalate (PET) resin chip, a polybutylene terephthalate (PBT) resin chip, and a polytrimethylene terephthalate resin chip, preferably It may include a polyethylene terephthalate (PET) resin chip.

In addition, the polyester-based resin chip of the present invention may have a glass transition temperature (Tg) of 60 ~ 100 ℃, preferably 70 ~ 90 ℃, more preferably 75 ~ 85 ℃.

In addition, the polyester-based resin chip of the present invention may have an intrinsic viscosity (I.V) of 0.55 to 0.75 dl/g, preferably 0.60 to 0.70 dl/g, more preferably 0.62 to 0.68 dl/g.

The orientation inhibitor chip of the present invention may include at least one selected from a polymethyl methacrylate-based resin chip, a polystyrene-based resin chip, and a methyl methacrylate-styrene-based copolymer resin chip, preferably polymethyl methacrylate. It may include a resin-based chip, more preferably a compound represented by the following formula (1).

[Formula 1]

In Formula 1, R ₁ , R ₂ , R ₃ and R ₄ are each independently a hydrogen atom or a C1 to C5 alkyl group, preferably R ₁ and R ₂ are each independently a hydrogen atom or a methyl group, R ₃ and R ₄ may each independently be a C1-C3 alkyl group.

In addition, in Formula 1, n may be a rational number satisfying a weight average molecular weight of 100,000 to 300,000, preferably 120,000 to 250,000, and more preferably 150,000 to 200,000.

In addition, the orientation inhibitor chip may have a glass transition temperature (Tg) of 100 to 140 °C, preferably 110 to 130 °C, more preferably 115 to 125 °C.

Next, in the second step of the method for producing a polyester staple fiber of the present invention, a composition for forming fibers in which a polyester resin chip and an orientation inhibitor chip are melted is put into a spinneret and spun, and then cooled to undrawn sub Tows (sub-tows) can be manufactured.

At this time, the composition for fiber formation may include 0.1 to 3.0 wt% of the molten orientation inhibitor chip, preferably 0.2 to 2.3 wt%, more preferably 0.7 to 1.3 wt%, based on the total weight%.

In addition, the composition for fiber formation may include 97.0 to 99.9% by weight of the molten polyester-based resin chip, preferably 97.7 to 99.8% by weight, more preferably 98.7 to 99.3% by weight, based on the total weight% .

In the melting of the second step, the polyester-based resin chip and the orientation inhibitor chip may be carried out at a temperature of 230 ~ 320 ℃, preferably 250 ~ 290 ℃.

In addition, the spinning of the second step may be performed under the conditions of a spinning temperature of 250 ~ 300 ℃, preferably 270 ~ 290 ℃, and a spinning speed of 1400 ~ 1800 m / min. At this time, if the spinning temperature is less than 250 ℃, there may be a problem of poor polymer discharge from the nozzle due to the increase in pack pressure. there may be

The spinning of the second step can be performed through various types of detention, and various sub-tows can be manufactured according to the type of detention.

On the other hand, the unstretched sub-tow prepared in the second step may have a fineness of 3.0 denier or less, preferably 1.0 to 3.0 denier, more preferably 1.5 to 2.3 denier, and if the fineness is 3.0 denier, If it exceeds, there may be a problem in that a problem of increasing the draw ratio occurs in the drawing process, and thus a fine fiber product cannot be manufactured.

In addition, the unstretched sub-tow manufactured in the second step may satisfy the following condition (3).

(3) 320% ≤ D ≤ 600%, preferably 370% ≤ D ≤ 560%, more preferably 410% ≤ D ≤ 510%

In the above condition (3), D represents the elongation at break of the unstretched sub tow. If D is less than 320%, there may be a problem in that a problem of increasing the draw ratio in the drawing process occurs, and thus a finely divided product cannot be manufactured.

Next, in the third step of the method for producing the polyester staple fiber of the present invention, the undrawn subtow prepared in the second step may be drawn.

At this time, the stretching may be performed by stretching the unstretched subtow to 3.5 to 4.5 times, preferably 3.5 to 4.0 times, under a temperature of 70° C. to 100° C. At this time, if the draw ratio is less than 3.5 times, there may be a problem in that fineness is increased, and if the draw ratio exceeds 4.5 times, there may be a problem that the undrawn sub tow is wound around the roller, so it is better to perform the stretching within the above range. .

Finally, in the fourth step of the method for producing a polyester staple fiber of the present invention, the subtow drawn in the third step may be heat-set and cut to manufacture a polyester staple fiber.

In this case, heat setting may be performed for 10 to 20 minutes under 60°C to 110°C, preferably 70°C to 90°C, after the stretched subtow is put into an oven. At this time, if the heat setting temperature is less than 60 ℃, there may be a problem of reducing the degree of crimping and number of crimps, and if it exceeds 110 ℃, there may be a problem of a decrease in shrinkage, so it is better to perform heat setting under the above temperature range.

In addition, the cutting in the fourth step is a process of cutting the heat-set sub tow so that the fiber has an appropriate fiber length according to the processed product to use the fiber, and it can be performed by a general cutting method used in the art. The polyester staple fiber of the present invention is preferably cut to have a fiber length of 20 to 70 mm, preferably 25 to 60 mm, and more preferably 30 to 50 mm.

Furthermore, the polyester staple fiber produced by the method for producing the polyester staple fiber of the present invention may have a fineness of 0.6 denier or less, preferably 0.4 to 0.6 denier, more preferably 0.45 to 0.55 denier.

In addition, the polyester staple fiber produced by the method for producing the polyester staple fiber of the present invention may satisfy the following condition (2).

(2) 15% ≤ C ≤ 28%, preferably 17% ≤ C ≤ 26%, more preferably 19% ≤ C ≤ 24%

In the above condition (2), C represents the elongation at break of the polyester staple fiber.

On the other hand, the manufacturing method of the nonwoven fabric of the present invention comprises the above-mentioned first step of manufacturing a nonwoven web by carding the polyester staple fiber of the present invention, and a second step of manufacturing a nonwoven fabric by heat treating the nonwoven web. may include

At this time, the heat treatment may be performed through a tenter process, in the tenter process process, the temperature of the tenter inlet is 150 ~ 190 ℃, preferably 160 ~ 180 ℃, the temperature of the tenter outlet is 180 ~ 220 ℃ , preferably 190 to 210 °C.

In the above, the present invention has been mainly described with respect to the embodiment, but this is only an example and does not limit the embodiment 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 embodiment of the present invention can be implemented by modification. And differences related to such modifications and applications should be construed as being included in the scope of the present invention defined in the appended claims.

Example 1: Preparation of polyester staple fibers

(1) A PET chip chipped with polyethylene terephthalate (PET) resin having an intrinsic viscosity of 0.65 dl/g and a glass transition temperature of 80° C. were prepared respectively.

[Formula 1-1]

In Formula 1-1, R ₁ and R ₂ are hydrogen atoms, R ₃ and R ₄ are methyl groups, and n is a rational number satisfying a weight average molecular weight of 181,000.

(2) The prepared PET chip and the orientation inhibitor chip were melted at a temperature of 265°C, and the composition for forming fibers was put into a spinneret and spun, and then cooled to prepare an undrawn subtow having a fineness of 1.90 denier.

At this time, the composition for fiber formation contained 99.0 wt% of a molten PET chip and 1.0 wt% of a molten orientation inhibitor chip with respect to the total weight%, and the spinning was performed under the conditions of a spinning temperature of 280°C and a spinning speed of 1600 m/min. After that, it was loaded into a can through a take-up process.

(3) The prepared unstretched subtow was stretched at a draw ratio of 3.8 times under a temperature of 90°C.

(4) After putting the stretched subtow in an oven, heat setting at 75° C. for 15 minutes and cutting, finally, polyester staple fiber having a fineness of 0.52 denier, a fiber length of 38 mm and an elongation of 21.2% did

Example 2: Preparation of polyester staple fibers

A polyester staple fiber was prepared in the same manner as in Example 1. However, unlike Example 1, the composition for fiber formation contains 99.5 wt% of a molten PET chip and 0.5 wt% of a molten orientation inhibitor chip with respect to the total weight%, and finally, polyester-based staple fibers as shown in Table 1 below. was prepared.

Example 3: Preparation of polyester staple fibers

A polyester staple fiber was prepared in the same manner as in Example 1. However, unlike Example 1, the composition for fiber formation contains 98.5 wt% of a molten PET chip and 1.5 wt% of a molten orientation inhibitor chip with respect to the total weight%, and finally, polyester-based staple fibers as shown in Table 1 below. was prepared.

Example 4: Preparation of polyester staple fibers

A polyester staple fiber was prepared in the same manner as in Example 1. However, unlike Example 1, the composition for fiber formation contains 98.0 wt% of a molten PET chip and 2.0 wt% of a molten orientation inhibitor chip with respect to the total weight%, and finally, polyester staple fibers as shown in Table 1 below. was prepared.

Example 5: Preparation of polyester staple fibers

A polyester staple fiber was prepared in the same manner as in Example 1. However, unlike Example 1, the composition for fiber formation contains 97.5 wt% of a molten PET chip and 2.5 wt% of a molten orientation inhibitor chip with respect to the total weight%, and finally, polyester-based staple fibers as shown in Table 1 below. was prepared.

Example 6: Preparation of polyester staple fibers

A polyester staple fiber was prepared in the same manner as in Example 1. However, unlike Example 1, the composition for fiber formation contains 97.0 wt% of a molten PET chip and 3.0 wt% of a molten orientation inhibitor chip with respect to the total weight%, and finally, polyester-based staple fibers as shown in Table 1 below. was prepared.

Example 7: Preparation of polyester staple fibers

A polyester staple fiber was prepared in the same manner as in Example 1. However, unlike Example 1, the composition for fiber formation was manufactured by including 96.0 wt% of a molten PET chip and 4.0 wt% of a molten orientation inhibitor chip with respect to the total weight%, but the rapid cooling effect of the polyester ( ≒ crystal orientation inhibitory effect) was increased, making it impossible to produce polyester staple fibers due to poor spinning.

Comparative Example 1: Preparation of polyester staple fibers

(1) A PET chip obtained by chipping a polyethylene terephthalate (PET) resin having an intrinsic viscosity of 0.65 dl/g and a glass transition temperature of 80°C was prepared.

(2) A composition for forming fibers obtained by melting the prepared PET chips at a temperature of 265°C was put into a spinneret and spun, and then cooled to prepare an undrawn subtow having a fineness of 0.7 denier.

At this time, the spinning was performed under the conditions of a spinning temperature of 280° C. and a spinning speed of 1600 m/min, and then loaded into a can through a take-up process.

(3) The prepared unstretched subtow was stretched at a draw ratio of 2.9 times under a temperature of 90°C.

(4) After putting the stretched subtow into an oven, heat setting at 75° C. for 15 minutes and cutting, finally, polyester staple fiber having a fineness of 0.68 denier, a fiber length of 38 mm and an elongation of 25.5% did.

Experimental Example 1: Measurement of physical properties of polyester composite fibers

Each of the polyester staple fibers prepared in Examples 1 to 7 and Comparative Example 1 was subjected to the experiments described below, and the results measured through these experiments are shown in Table 1 below.

1. Measurement of Elongation at Break

Using an automatic tensile tester (FAVIMAT), a speed of 40 mm/min and a gripping distance of 10 mm were applied to measure the elongation at break of the undrawn subtow and the polyester staple fiber, respectively. Elongation at break was defined as the value (%) expressed as a percentage of the initial length to the elongated length when the fiber was stretched until it was cut by applying a constant force.

2. Measurement of spinning workability

Spinning workability was indicated as good if there was no fiber breakage and no dripping during spinning, somewhat poor if some fiber breakage and dripping occurred, and poor if a lot of fiber breakage and dripping occurred.

As can be seen in Table 1, the unstretched subtow prepared in Comparative Example 1 had a significantly lower elongation at break than the unstretched subtow prepared in Examples 1 to 6, and the draw ratio was significantly lower in performing stretching. It was confirmed that the fineness of the polyester staple fibers to be used was significantly increased.

In addition, it was confirmed that the polyester staple fiber prepared in Example 1 had the lowest fineness, and the polyester staple fiber prepared in Examples 2 to 4 compared to the polyester staple fiber prepared in Example 1 was confirmed to have a rather high fineness, and it was confirmed that the polyester staple fibers prepared in Examples 5 to 6 not only had a high fineness, but also had somewhat poor spinning workability.

Although one embodiment of the present invention has been described above, the spirit of the present invention is not limited to the embodiments presented herein, and those skilled in the art who understand the spirit of the present invention can add components within the scope of the same spirit. , changes, deletions, additions, etc. may easily suggest other embodiments, but this will also fall within the scope of the present invention.

Claims (16)

In the polyester staple fiber produced by spinning the composition for forming fibers,
The composition for forming fibers includes a polyester-based resin and an orientation inhibitor,
The polyester staple fiber is a polyester staple fiber, characterized in that the fineness is 0.6 denier or less.
According to claim 1,
The polyester staple fiber, characterized in that the orientation inhibitor comprises a compound represented by the following formula (1).
[Formula 1]

In Formula 1, R ₁ , R ₂ , R ₃ and R ₄ are each independently a hydrogen atom or a C1-C5 alkyl group, and n is a rational number satisfying a weight average molecular weight of 100,000 to 300,000.
According to claim 1,
Polyester staple fiber, characterized in that the composition for forming fibers comprises 0.1 to 3.0 wt% of an orientation inhibitor with respect to the total weight%.
According to claim 1,
The polyester staple fiber is a polyester staple fiber, characterized in that the fiber length is 20 ~ 70mm.
According to claim 1,
The polyester staple fiber is a polyester staple fiber, characterized in that it satisfies the following condition (1).
(1) 20℃ ≤ B - A
In the above condition (1), A is the glass transition temperature (Tg) of the polyester-based resin, B is the glass transition temperature (Tg) of the orientation inhibitor.
6. The method of claim 5,
The polyester staple fiber is a polyester staple fiber, characterized in that it satisfies the following condition (2).
(2) 15% ≤ C ≤ 28%
In the above condition (2), C represents the elongation at break of the polyester staple fiber.
6. The method of claim 5,
The polyester-based resin has a glass transition temperature (Tg) of 60 ~ 100 ℃,
Polyester staple fiber, characterized in that the orientation inhibitor has a glass transition temperature (Tg) of 100 ~ 140 ℃.
According to claim 1,
The polyester-based resin comprises at least one selected from a polyethylene terephthalate (PET) resin, a polybutylene terephthalate (PBT) resin, and a polytrimethylene terephthalate resin.
9. The method of claim 8,
The polyester-based resin has an intrinsic viscosity (IV) of 0.55 to 0.75 dl/g.
A nonwoven fabric comprising the polyester staple fibers of any one of claims 1 to 9.
A first step of preparing a polyester-based resin chip and an orientation inhibitor chip, respectively;
a second step of preparing an unstretched sub-tow by injecting and spinning the composition for forming fibers in which the polyester-based resin chip and the orientation inhibitor chip are melted into a spinneret, followed by cooling;
a third step of stretching the undrawn sub tow; and
a fourth step of heat-setting and cutting the drawn sub-tow to produce a polyester staple fiber; including,
The prepared polyester staple fiber is a method for producing a polyester staple fiber, characterized in that the fineness is 0.6 denier or less.
12. The method of claim 11,
The polyester staple fiber is a method for producing a polyester staple fiber, characterized in that it satisfies the following conditions (1) and (2).
(1) 20℃ ≤ B - A
(2) 15% ≤ C ≤ 28%
In the above condition (1), A is the glass transition temperature (Tg) of the polyester-based resin, B is the glass transition temperature (Tg) of the orientation inhibitor,
In the above condition (2), C represents the elongation at break of the polyester staple fiber.
12. The method of claim 11,
The orientation inhibitor chip is a method for producing a polyester staple fiber, characterized in that it comprises a compound represented by the following formula (1).
[Formula 1]

In Formula 1, R ₁ , R ₂ , R ₃ and R ₄ are each independently a hydrogen atom or a C1-C5 alkyl group, and n is a rational number satisfying a weight average molecular weight of 100,000 to 300,000.
12. The method of claim 11,
The composition for forming fibers is a method for producing a polyester staple fiber, characterized in that it comprises 0.1 to 3.0% by weight of the molten orientation inhibitor chip based on the total weight%.
12. The method of claim 11,
The undrawn subtow has a fineness of 3.0 denier or less, and the following condition (3) is satisfied.
(3) 320% ≤ D ≤ 600%
In the above condition (3), D represents the elongation at break of the undrawn sub tow.
12. The method of claim 11,
The method for producing a polyester staple fiber, characterized in that the drawing is performed at a draw ratio of 3.5 to 4.5 times.