KR20110134165A - Polyester staple fiber having low melting point and manufacturing method thereof - Google Patents

Abstract

PURPOSE: A polyester staple fiber with low melting point and a method for fabricating the same using isophtalic acid and diethylene glycol is provided. CONSTITUTION: A polyester staple fiber with low melting point contais polyester with low melting temperature. The polyester contains 100 weight parts of terephthalic acid(TPA), 47-75 weight parts of isophthalic acid(IPA), 67-74 weight parts of ethylene glycol(EG), and 2.5-13 weight parts of diethylene glycol(DEG). The polyester is prepared by primary esterification of terephthalic acid, ethylene glycol, and diethylene glycol and second esterification of isophthalic acid and ethylene glycol.

Description

Low melting point polyester short fiber and its manufacturing method {Polyester Staple fiber having low melting point and Manufacturing method

The present invention relates to a low melting point polyester short fiber and a method for manufacturing the same, and more particularly, to a low melting point polyester short fiber prepared by copolymerization and melted at a low temperature to improve adhesion.

In general, synthetic fibers have a high melting point and are rarely limited in use. In particular, when the fiber fabric itself is used as a wick or the like, and is used as an adhesive that is interposed between a tape-like fabric and press-bonded, the textile fabric itself may be thermally deteriorated by heating, and special equipment such as a high frequency sewing machine may be used. Because of the hassle that must be used, it is desired to adhere easily by a conventional simple hot press without using such special equipment.

Conventional low melting polyester short fibers have been widely used as hot melt binder fibers for the purpose of bonding different types of fibers in mutual fiber structures used in manufacturing mattresses, interior materials for automobiles, or various nonwoven fabrics. .

Therefore, the demand for low melting point in polyester resin is high, and it is used for binder fiber, an adhesive agent, etc. Generally, copolymerized polyester is used for such a use.

For example, U.S. Patent No. 4,129,675 introduces low melting point polyesters copolymerized using terephthalic acid (TPA) and isophthalic acid (IPA), but isophthalic acid (IPA) is expensive. Low melting point polyester using a large amount of isophthalic acid as a material has a problem of low competitiveness due to high production cost.

In addition, Japanese Patent Application Laid-open No. Hei 10-298271 uses adipic acid instead of terephthalic acid in the process of polymerization to improve crystallinity and heat resistance, and 1,4-butanediol (BD) as a diol component instead of ethylene glycol. ) To improve the adhesiveness and to provide a fiber with little decrease in the strength of the fiber even at a high temperature, but low melting point polyester produced using adipic acid is a low melting point polyester having a melting point of 150 ° C. or less. There was a problem that it is difficult to prepare a low melting point polyester of lower melting point.

The present invention has been invented to solve the above problems, an object of the present invention is to provide a low melting point polyester short fiber having a high melting point at a melting point of 150 ° C. or less and a method for producing the same.

In addition, to solve the problem of separating the adhesive site over time with excellent adhesion properties (solubility parameter) and to provide a good method for producing a low melting polyester short fibers that do not separate even after the elapsed time. .

The present invention is polymerized with terephthalic acid (TPA), isophthalic acid (isophthalic acid (IPA) as an acid component of ethylene glycol (EG), diethylene glycol (DEG) as a diol component It provides a low melting point polyester short fiber comprising a low melting point polyester having a degree of polymerization (Pn) of 60 to 90.

In addition, the low-melting polyester is 47 to 75 parts by weight of isophthalic acid (IPA), 67 to 74 parts by weight of ethylene glycol (EG), diethylene glycol 100 parts by weight of terephthalic acid (TPA) (diethylene glycol: DEG) provides a low-melting polyester short fibers, characterized in that the mixture is prepared by mixing 2.5 to 13 parts by weight.

In addition, the low-melting polyester is a first esterification reaction of terephthalic acid (TPA), ethylene glycol (ethylene glycol: EG), diethylene glycol (DEG), isophthalic acid (isophthalic acid: IPA) ), To provide a low-melting polyester short fibers, characterized in that the secondary esterification reaction by the addition of ethylene glycol (EG).

In addition, the low-melting polyester is 47 to 75 parts by weight of isophthalic acid (IPA), 67 to 74 parts by weight of ethylene glycol (EG), diethylene glycol 100 parts by weight of terephthalic acid (TPA) (diethylene glycol: DEG) is prepared by mixing 2.5 to 13 parts by weight,

In addition, the ethylene glycol (EG) is a low melting point poly, characterized in that 10 to 95% by weight of the addition amount is added in the first esterification reaction and 5 to 90% by weight is added in the secondary esterification reaction. Provides ester short fibers.

In addition, the low melting point polyester provides a low-melting point polyester short fiber characterized in that it comprises 40 to 70% by weight.

In addition, the low melting point polyester provides a low melting point polyester short fiber characterized in that the softening point of 80 ~ 110 ℃.

In addition, the low melting point polyester provides a low melting point polyester short fiber, characterized in that the glass transition temperature (Tg) of 55 ~ 70 ℃.

It provides a low melting point polyester short fiber characterized in that the intrinsic viscosity (IV) of the low melting point polyester is 0.45 ~ 0.75.

In addition, the low melting point polyester short fiber provides a low melting point polyester short fiber, characterized in that 5 ~ 100mm.

In addition, the present invention is a method for producing a low-melting polyester short fibers, ethylene glycol (EG), diethylene glycol (Tephthalic acid (TPA), isophthalic acid (IPA) as an acid component polyester production step of polymerizing diethylene glycol: DEG) into a diol component to produce a low melting point polyester having a degree of polymerization (Pn) of 60 to 90; Fiber manufacturing step of producing a fiber by spinning, stretching the polymerized low melting point polyester with a general polyester; And it provides a low melting point polyester short fiber manufacturing method comprising the step of cutting the prepared fiber to produce a short fiber.

In addition, the polyester manufacturing step, 47 to 75 parts by weight of isophthalic acid (IPA), ethylene glycol (ethylene glycol: EG) 67 to 74 parts by weight, 100 parts by weight of terephthalic acid (TPA) A mixing process of preparing a mixture by mixing 2.5 to 13 parts by weight of glycol (diethylene glycol: DEG) at 200 to 230 ° C; An esterification step of esterifying the mixture for 2 to 4 hours at 240 to 260 ° C. under a pressure of 2.0 to 2.5 kgf / cm 2; And it provides a low-melting point polyester short fiber manufacturing method characterized in that the ester reactant is produced by a polycondensation process of polymerization in a vacuum of 0.1 ~ 1 Torr or less for 275 ~ 285 ℃, 40 ~ 100 minutes.

In addition, the polyester manufacturing step, 10 to 95% by weight of ethylene glycol (ethylene glycol: EG) 67 to 74 parts by weight of terephthalic acid (TPA), diethylene glycol (DEG) 2.5 A first mixing step of mixing ˜13 parts by weight at 200˜230 ° C .; A primary esterification step of esterifying the mixture of the first mixing step at 240 to 260 ° C. for 2 to 4 hours at 2.0 to 2.5 kgf / cm 2 pressure; A second mixture of 5 to 90% by weight of the ethylene glycol (EG) 67 to 74 parts by weight, and 47 to 75 parts by weight of isophthalic acid (IPA) at 230 to 240 ° C. fair; A secondary esterification step of esterifying the mixture of the second mixing step at 240 to 260 ° C. for 2 to 4 hours at 2.0 to 2.5 kgf / cm 2 pressure; And it provides a low-melting point polyester short-fiber manufacturing method characterized in that the secondary ester reactant is produced by a polycondensation process of polymerization in a vacuum of 0.1 ~ 1 Torr or less for 275 ~ 285 ℃, 40 ~ 100 minutes.

In addition, the polymerization degree (Pn) of the low melting point polyester in the polycondensation process provides a low melting point polyester short fiber manufacturing method characterized in that the polymerization to 60 ~ 90.

In addition, the polycondensation process provides a low melting point polyester short fiber manufacturing method characterized in that the addition of phosphoric acid or phosphorus flame retardant.

In addition, the fiber manufacturing step, the low melting point of the polyester to the sheath portion, the general polyester to the core portion spinning process at a spinning speed of 1100 ~ 1500mpm at 250 ~ 290 ℃; It provides a low melting point polyester short-fiber manufacturing method characterized in that the fiber is produced by the stretching step of stretching at a draw ratio of 2.0 to 4.0 in a 50 ~ 80 ℃ hot bath.

In addition, the weight ratio of the sheath portion and the core portion provides a method for producing a crystalline low melting polyester composite fiber, characterized in that 40:60 to 70:30.

In addition, the cutting step provides a low-melting point polyester short fiber manufacturing method characterized in that the low-melting point polyester fiber is cut into 5 ~ 100mm.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. First, it should be noted that in the drawings, the same components or parts denote the same reference numerals as much as possible. In describing the present invention, detailed descriptions of related well-known functions or configurations are omitted in order not to obscure the subject matter of the present invention.

As used herein, the terms "about", "substantially", and the like, are used at, or in close proximity to, numerical values when manufacturing and material tolerances inherent in the meanings indicated are intended to aid the understanding of the invention. Accurate or absolute figures are used to assist in the prevention of unfair use by unscrupulous infringers.

In the present invention, terephthalic acid (TPA) and isophthalic acid (isophthalic acid: IPA) is ethylene glycol (ethylene glycol: EG), diethylene glycol (DIG) is polymerized as a diol component It is a low melting polyester short fiber containing the low melting polyester of 60-90 degree of polymerization (Pn).

Generally, the melting point of polyester is controlled by isophthalic acid (IPA), adipic acid, 1, 4-butanediol, neopentyl glycol, and the like. The low melting point polyester of the present invention is prepared by adding a copolymer, but the low melting point polyester of the present invention is prepared by adjusting the degree of polymerization so that radioactivity and physical properties are not reduced using only isophthalic acid (IPA). Short fibers are made of polyester.

The low melting polyester of the present invention is prepared by copolymerizing isophthalic acid (IPA).

In general, the copolymer may be divided into a random copolymer and a block copolymer.

The random copolymer is a copolymer in which monomers having different chemical structures are randomly connected to form a polymer chain, and a block copolymer is a copolymer in which several units of chemically identical monomers are arranged according to the main polymer chain. .

The block copolymer can arbitrarily control the content of each compound to be polymerized compared to the random copolymer, and has the advantage of easily controlling the molecular weight and physical properties.

The low-melting polyester of the present invention may use both random co-polyester and block co-polyester.

The low-melting polyester according to the present invention is 47 to 75 parts by weight of isophthalic acid (IPA), 67 to 74 parts by weight of ethylene glycol (EG), diethylene to 100 parts by weight of terephthalic acid (TPA) It is prepared by mixing 2.5 to 13 parts by weight of glycol (diethylene glycol: DEG).

When the low-melting polyester of the present invention is prepared as a random copolymerized polyester, 47 to 75 parts by weight of isophthalic acid (IPA) and 100 parts by weight of terephthalic acid (TPA) and ethylene glycol (EG) 67 to 74 parts by weight, diethylene glycol (DEG) 2.5 to 13 parts by weight of the mixture after the esterification reaction, it is possible to produce a low-melting polyester through heavy fusion.

When the low melting point polyester of the present invention is prepared as a block copolymerized polyester, terephthalic acid (TPA), ethylene glycol (ethylene glycol: EG), and diethylene glycol (DEG) are subjected to primary esterification reaction. Then, isophthalic acid (isophthalic acid: IPA), ethylene glycol (ethylene glycol: EG) by adding a secondary esterification reaction can be prepared through the low-block copolymerization low-melting polyester.

The block copolymer low-melting polyester is 47 to 75 parts by weight of isophthalic acid (IPA), 67 to 74 parts by weight of ethylene glycol (EG), diethylene glycol 100 parts by weight of terephthalic acid (TPA) (diethylene glycol: DEG) 2.5 to 13 parts by weight is prepared by primary and secondary ester reactions.

When added to less than 10% by weight of the total amount of ethylene glycol in the primary esterification or less than 5% by weight of the total amount of ethylene glycol in the secondary esterification, the effect of block copolymerization is insignificant Ethylene glycol (EG) is preferably added 10 to 95% by weight of the addition amount in the first esterification reaction and 5 to 90% by weight in the second esterification reaction.

In the random copolymerized low melting point polyester or the block copolymerized low melting point polyester, it is preferable that the degree of polymerization (Pn) is all produced at 60 to 90 degrees. If the polymerization degree is less than 60, the radioactivity may be deteriorated, which may cause a problem in use. When the polymerization degree exceeds 90, the melting point may be increased.

It will be preferable to produce a polymerization degree of 60 to 90 as described above and to produce a softening point of low melting polyester at 80 to 110 ° C.

The diethylene glycol (DEG) to lower the melting point of the polyester with isophthalic acid (IPA) to lower the crystallinity of the polyester during the polymerization process to lower the melting point, low melting point polyester After the preparation, the functional group is more functionalized in ethylene glycol than the polyester produced from ethylene glycol improves the dyeability and hygroscopicity.

As described above, the low-melting polyester prepared with terephthalic acid and isophthalic acid as an acid component and ethylene glycol and diethylene glycol as a diol component should have an intrinsic viscosity (IV) of 0.45 to 0.75. If the intrinsic viscosity is less than 0.45, the physical properties of the polyester produced is poor and the heat resistance is difficult to use, and if the intrinsic viscosity exceeds 0.75, the melting point becomes high and the target melting point cannot be obtained.

Moreover, it is preferable that the glass transition temperature (Tg) of the said block copolymerization low melting point polyester is 55-70 degreeC.

The method for producing a random copolymer low melting point polyester is a mixture of terephthalic acid (TPA), isophthalic acid (IPA), ethylene glycol (EG) and diethylene glycol (DEG). It comprises a mixing step, an esterification step of esterifying the mixture, and a polycondensation step of polymerizing the ester reactant.

The mixing process is 47 to 75 parts by weight of isophthalic acid (IPA), 67 to 74 parts by weight of ethylene glycol (EG), diethylene glycol (diethylene glycol: 100 parts by weight of terephthalic acid (TPA) DEG) 2.5 to 13 parts by weight of the mixture to prepare a mixture to proceed to the next step of the esterification process should be carried out at 200 ~ 230 ℃ mixing process.

The esterification step is a step of esterifying the acid component of terephthalic acid, isophthalic acid and the diol component of ethylene glycol, diethylene glycol to produce an ester reaction, the mixture is 240 ~ 260 ℃, under 2.0 ~ 2.5 kgf / ㎠ pressure, It is a process of esterifying for 2-4 hours.

The polycondensation step is a step of polymerizing a low-melting point polyester by polycondensing the ester reactant produced in the esterification step, and polymerizing for 275-285 ° C. and 40-100 minutes in a vacuum state of 0.1 to 1 Torr or less. .

The method for producing the block copolymer low-melting polyester is a first mixing step of mixing terephthalic acid (TPA), ethylene glycol (EG), diethylene glycol (DEG), the first mixing First esterification step of esterifying the mixture of the step, a second mixing step of mixing ethylene glycol (EG), isophthalic acid (IPA) to the primary ester reactant, the second mixture It is prepared including a secondary esterification step of esterifying the mixture of the step, and a polycondensation step of polymerizing the secondary ester reactant.

The first mixing process is 5 to 90% by weight of 67 to 74 parts by weight of ethylene glycol (EG), diethylene glycol (DEG) 2.5 to 13 parts by weight of terephthalic acid (TPA) 100 parts by weight The process of mixing the part at 200 ~ 230 ℃ should be carried out at 200 ~ 230 ℃ to smoothly proceed to the next step of the esterification process.

The first esterification step is a step of esterifying an acid component of terephthalic acid and a diol component of ethylene glycol and diethylene glycol to generate an ester reactant. The mixture of the first mixing process is 240 at a pressure of 2.0 to 2.5 kgf / cm 2. It is a process of esterifying for 260 degreeC and 2 to 4 hours.

In the second mixing process, 5 to 90% by weight of the ethylene glycol (EG) 67 to 74 parts by weight and 47 to 75 parts by weight of isophthalic acid (IPA) are 230 to 240 ° C. in the primary ester reactant. In order to proceed with the second esterification process smoothly, the mixing process should be carried out at 230 ~ 240 ℃.

The second esterification step is a step of producing an ester reactant by adding an acid component of isophthalic acid and a diol component of ethylene glycol to produce an ester reactant. The mixture of the first mixing step is 240- under a pressure of 2.0-2.5 kgf / cm 2. It is a process of esterifying at 260 degreeC for 2 to 4 hours.

The polycondensation step is a step of polymerizing a low melting point polyester by polycondensing the ester reactant produced in the secondary esterification step to polymerize for 275 ~ 285 ℃, 40 ~ 100 minutes in a vacuum of 0.1 ~ 1 Torr or less It is a process.

Polycondensation in the production of a general polyester is prepared by polymerization for 3 hours or more, but the polycondensation process of the present invention controls the degree of polymerization by polymerization for 40 to 100 minutes.

If the polymerization time is less than 40 minutes, the degree of polymerization may be lowered to less than 60, and the yield may be lowered, which may be a problem for radioactivity. If the polymerization time exceeds 100 minutes, the degree of polymerization may increase and the melting point may be increased. May exceed 90.

The most preferable heavy fusion time of the process time of the above-mentioned heavy fusion process is 50-90 minutes.

Antimony trioxide (Sb ₂ O ₃ ), titanium oxide and dibutyl tin dilaurate may be used as the reaction catalyst in the polycondensation process, it will be preferable to use antimony trioxide (Sb ₂ O ₃ ).

It is also possible to add flame retardants for the thermal stability of the ester reactants. The flame retardant may be phosphoric acid or phosphorus based flame retardant. When using the above phosphoric acid it is preferable to use H ₃ PO ₄ , it is preferable to use a phosphate ester flame retardant when using a phosphorus flame retardant.

In addition, in the polycondensation process, TiO ₂ or SiO ₂ may be added as a quencher to prepare polyester from which light is removed.

Low-melting polyester of the present invention prepared by mixing terephthalic acid (TPA), isophthalic acid (IPA), ethylene glycol (EG), diethylene glycol (DEG) as described above The isophthalic acid, the action of diethylene glycol and a polymerization point of 60 ~ 90 softening point (SP) can produce a low melting point polyester of 80 ~ 110 ℃.

It is preferable that the low-melting polyester produced in the above is contained 40 to 70% by weight in short fibers. When included in less than 40% by weight less adhesiveness, in excess of 70% by weight may be less radioactive.

The method for producing low melted polyester short fibers according to the present invention is prepared by a polyester manufacturing step, a fiber manufacturing step, and a cutting step.

As described above, the polyester manufacturing step includes terephthalic acid (TPA) and isophthalic acid (IPA) as ethylene glycol (EG) and diethylene glycol (DEG). It is a step of preparing a low melting polyester having a degree of polymerization (Pn) of 60 to 90 by polymerization with a diol component.

The fiber manufacturing step is to produce a fiber from the low-melting point polyester and the general polyester, the low-melting point polyester to the sheath portion, the general polyester to the core portion at a spinning speed of 1100 ~ 1500mpm at 250 ~ 290 ℃ A low melting polyester fiber may be produced by a spinning step of spinning and a stretching step of stretching the spun fiber at a draw ratio of 2.0 to 4.0 in a 50 to 80 ° C. warm bath.

The general polyester may be used a polyester-based resin sold, it will be most preferable to use polyethylene terephthalate (polyethylene terephthalate).

The weight ratio of the sheath portion and the core portion is preferably 40:60 to 70:30 to produce a low melting point polyester fiber.

After the stretching step, post-treatment such as heat treatment, crimping and the like can be performed.

The heat treatment process may be performed by using a plurality of heat rollers in a process of increasing the safety of the fiber by heat-setting the stretched fiber by heat-treating the stretched fiber at 90 ~ 120 ℃.

The cutting step is a step of cutting the prepared polyester fiber into short fibers, preferably short fiber length of 5 ~ 100mm.

The low melting point polyester short fiber according to the present invention has the effect of using isophthalic acid and diethylene glycol to provide a low melting point polyester short fiber having a lower melting point than conventional low melting point polyester short fibers.

In addition, the low-melting polyester short fibers of the present invention is made of a low-melting polyester using diethylene glycol, thereby reducing the use of expensive isophthalic acid, thereby improving the economics of the low-melting polyester short fibers.

In addition, the use of diethylene glycol is excellent in the dyeability, good absorbency block copolymer low melting point polyester short fibers can be used in various business fields.

Hereinafter, although the Example of the method for manufacturing the low melting polyester short fiber of this invention is shown, it is not limited.

Examples 1-18

Terephthalic acid (TPA), isophthalic acid (IPA), ethylene glycol (EG) and diethylene glycol (DEG) are mixed at 220 ° C., and the pressure is 2.1 to 2.3 kgf / cm 2. After the esterification for 3 hours under 240 ~ 260 ℃, the ester reaction was polymerized at 278 ~ 283 ℃ in a vacuum of 0.3 Torr or less to prepare a low-melting polyester according to the present invention.

Examples 1 to 7 were polymerized with a polymerization time of 50 minutes, and Examples 8 to 14 were polymerized with a polymerization time of 90 minutes.

Examples 15 and 17 were polymerized in the same composition ratio as in Example 6, and Examples 16 and 18 were polymerized in the same composition as in Example 13, and were polymerized by changing the polymerization time.

Examples 15 and 16 polymerized with a polymerization time of 30 minutes and Examples 17 to 18 polymerized with a polymerization time of 120 minutes.

Composition ratios of the terephthalic acid, isophthalic acid, ethylene glycol and diethylene glycol are shown in Table 1 below.

division
Input amount (% by weight) TPA IPA EG DEG Example 1 39.9 26.2 29.6 4.4 Example 2 40.3 26.3 29.9 3.5 Example 3 40.5 26.4 30.0 3.1 Example 4 41.3 25.2 29.8 3.6 Example 5 43.9 22.1 29.6 4.4 Example 6 40.8 26.0 29.9 3.3 Example 7 42.2 24.4 29.9 3.5 Example 8 41.2 25.3 29.8 3.7 Example 9 41.7 25.3 30.1 2.9 Example 10 43.4 21.8 29.2 5.6 Example 11 44.0 21.8 29.5 4.6 Example 12 44.1 21.8 29.5 4.6 Example 13 44.3 21.8 29.6 4.3 Example 14 40.5 26.3 29.9 3.3 Example 15 40.8 26.0 29.9 3.3 Example 16 44.0 21.8 29.5 4.6 Example 17 40.8 26.0 29.9 3.3 Example 18 44.0 21.8 29.5 4.6

Examples 19-26

Terephthalic acid (TPA), ethylene glycol (EG) and diethylene glycol (DEG) were mixed at 220 ° C, and 240-260 ° C for 3 hours under 2.1-2.3 kgf / cm2 pressure. After primary esterification, ethylene glycol (EG) and isophthalic acid (IPA) were mixed with the ester reactant of the primary esterification at 230 ° C., and 240 ° C under pressure of 2.1 to 2.3 kgf / cm 2. Secondary esterification for 3 h at 260 < 0 > C.

The ester reactant of the secondary esterification was polymerized at 278-283 ° C. under a vacuum of 0.3 Torr or less to prepare a low melting polyester according to the present invention.

Examples 19 to 21 were polymerized with a polymerization time of 60 minutes, and Examples 22 to 24 were polymerized with a polymerization time of 90 minutes.

Example 25 was polymerized in the same composition ratio as in Example 20 with a polymerization time of 30 minutes, and Example 26 was polymerized in the same composition ratio as in Example 22 with a polymerization time of 140 minutes.

 The composition ratio of the terephthalic acid, isophthalic acid, ethylene glycol, diethylene glycol is shown in Table 2 below, the amount of the primary and secondary mixing process of the ethylene glycol was added half of the total addition amount.

division
Input amount (% by weight) TPA IPA EG DEG Example 19 43.3 25.0 30.6 1.2 Example 20 39.2 28.7 30.4 1.7 Example 21 35.8 31.9 30.4 1.9 Example 22 40.1 26.4 29.8 3.6 Example 23 40.7 25.7 29.7 3.9 Example 24 40.4 25.9 29.7 4.0 Example 25 39.2 28.7 30.4 1.7 Example 26 40.1 26.4 29.8 3.6

The softening point (SP), glass transition temperature (Tg), intrinsic viscosity, and polymerization degree of the low melting point polyester according to the present invention prepared above are shown in Table 3.

In addition, the low-melting polyester of the above embodiments as a sheath part, as a general polyester using polyethylene terephthalate as a core part and spinning at a spinning speed of 1350mpm at 280 ℃ and 3.0 ~ in a warm bath of 70 ~ 75 ℃ The drawing process of drawing at a draw ratio of 3.10 and the low melting point polyester short fiber were produced by the cutting process cut to 6-55 mm, and the radioactivity was shown in Table 3 below.

division SP (℃) Tg (占 폚) IV Degree of polymerization Radioactive Example 1 86 62.8 0.463 67.41 ○ Example 2 99.9 63.2 0.556 64.87 ○ Example 3 102.6 67.1 0.595 64.39 ○ Example 4 99.0 58.8 0.637 70.74 ○ Example 5 102.0 51.3 0.676 68.65 ○ Example 6 102.0 55.0 0.696 69.02 ○ Example 7 98.5 61.9 0.577 66.78 ○ Example 8 99.2 64.3 0.634 69.42 ○ Example 9 99.3 60.5 0.582 76.50 ○ Example 10 90.1 60.2 0.484 71.36 ○ Example 11 95.0 61.6 0.517 75.55 ○ Example 12 98.9 65.7 0.545 68.51 ○ Example 13 93.3 63.8 0.530 76.84 ○ Example 14 93.6 61.9 0.509 76.43 ○ Example 15 79.9 50.7 0.410 44.62 △ Example 16 148 67.8 0.573 93.57 ○ Example 17 80.6 55.8 0.397 41.06 △ Example 18 134 65.6 0.627 97.17 ○ Example 19 86 62.8 0.463 68.1 ○ Example 20 99.9 63.2 0.556 62.8 ○ Example 21 102.6 67.1 0.595 69.2 ○ Example 22 99.0 58.8 0.637 71.5 ○ Example 23 102.0 51.3 0.676 74.7 ○ Example 24 102.0 55.0 0.696 80.4 ○ Example 25 84.3 49.3 0.409 52.6 △ Example 26 162.0 79.6 0.766 94.3 ○

As shown in Table 3, in Examples 1 to 14 and 19 to 24, the polymerization time was polymerized in 50 minutes and 90 minutes, it can be seen that the softening point can be melted at a low temperature below 105 ° C.

In the case of Examples 15, 17 and 25 having a polymerization time of 30 minutes, it was found to have a lower softening point, but there was a problem in use due to poor radioactivity. In this case, the low melting polyester of the present invention has a high softening point, and a polymerization time of 40 to 100 minutes will be most preferable.

Table 4 shows the physical properties of the short fibers produced in Example 11 and Example 20 among the short fibers in the examples drawn above.

division Example 11 Example 20 Spinning temperature (℃) 280 280 Spinning speed (mpm) 1350 1350 Cross section condition Sheath-core Sheath-core Sheath core weight ratio 60/40 60/40 Drawing temperature (℃) 73 72 Elongation ratio 3.07 3.05 Denier 2.99 2.98 Fiber length (mm) 6 51 Strength (kg / d) 3.07 3.06 Shinto (%) 36.9 32.2 Shrinkage (%) 5.2 4.4 Adhesive ○ ○

As shown in Table 4, it can be seen that the short fibers of the embodiments are low melting polyester short fibers having excellent physical properties when the adhesiveness is excellent.

The present invention described above is not limited to the above-described embodiments, and various substitutions, modifications, and changes can be made without departing from the technical spirit of the present invention. It will be obvious to him.

Claims (17)

Terephthalic acid (TPA) and isophthalic acid (IPA) are polymerized with ethylene glycol (EG) and diethylene glycol (DIG) as diol components, and the degree of polymerization (Pn) Low melting point polyester short fiber, characterized in that it comprises a low melting point polyester of 60 ~ 90. The method of claim 1,
The low-melting polyester is 47 to 75 parts by weight of isophthalic acid (IPA), 67 to 74 parts by weight of ethylene glycol (EG), diethylene glycol (diethylene) in 100 parts by weight of terephthalic acid (TPA) glycol: DEG) Low melting point polyester short fiber, characterized in that it is prepared by mixing 2.5 to 13 parts by weight. The method of claim 1,
The low-melting polyester is the first esterification of terephthalic acid (TPA), ethylene glycol (ethylene glycol: EG), diethylene glycol (DEG), isophthalic acid (isophthalic acid (IPA), Low-melting polyester short fibers, characterized in that prepared by the second esterification by adding ethylene glycol (EG). The method of claim 3,
The low-melting polyester is 47 to 75 parts by weight of isophthalic acid (IPA), 67 to 74 parts by weight of ethylene glycol (EG), diethylene glycol (diethylene) in 100 parts by weight of terephthalic acid (TPA) glycol: DEG) is prepared by mixing 2.5 to 13 parts by weight,
The ethylene glycol (EG) is a low-melting polyester stage, characterized in that 10 to 95% by weight of the addition amount is added in the first esterification reaction and 5 to 90% by weight is added in the second esterification reaction. fiber. The method of claim 1,
Low-melting-point polyester short fibers, characterized in that containing 40 to 70% by weight of the low-melting point polyester. The method according to any one of claims 1 to 5,
The low melting point polyester short fiber, characterized in that the softening point of the low melting point polyester is 80 ~ 110 ℃. The method according to any one of claims 1 to 5,
The low melting point polyester short fiber, characterized in that the glass transition temperature (Tg) of the polyester is 55 ~ 70 ℃. The method according to any one of claims 1 to 5,
Low-melting-point polyester short fiber, characterized in that the intrinsic viscosity (IV) of the low-melting point polyester is 0.45 ~ 0.75. The method according to any one of claims 1 to 5,
The low melting point polyester short fiber is a low melting point polyester short fiber, characterized in that 5 to 100mm in length. In the method for producing a low melting polyester short fiber,
Terephthalic acid (TPA), isophthalic acid (isophthalic acid (IPA)) as an acid component of ethylene glycol (ethylene glycol: EG), diethylene glycol (diethylene glycol: DEG) is polymerized by diol (diol) Polyester manufacturing step to produce a low melting point polyester of 60 ~ 90;
Fiber manufacturing step of producing a fiber by spinning, stretching the polymerized low melting point polyester with a general polyester; And
The low melting point polyester short fiber manufacturing method, characterized in that it comprises a cutting step of cutting the prepared fiber into short fibers. The method of claim 10,
The polyester manufacturing step,
100 parts by weight of terephthalic acid (TPA), 47 to 75 parts by weight of isophthalic acid (IPA), 67 to 74 parts by weight of ethylene glycol (EG), diethylene glycol (DEG) 2.5 to Mixing process for producing a mixture by mixing 13 parts by weight at 200 ~ 230 ℃;
An esterification step of esterifying the mixture for 2 to 4 hours at 240 to 260 ° C. under a pressure of 2.0 to 2.5 kgf / cm 2; And
The low melting point polyester short fiber manufacturing method characterized in that the ester reactant is produced by a polycondensation step of polymerization in a vacuum at 0.1 ~ 1 Torr or less for 275 ~ 285 ℃, 40 ~ 100 minutes. The method of claim 10,
The polyester manufacturing step,
10 to 95% by weight of 67 to 74 parts by weight of ethylene glycol (EG) and 2.5 to 13 parts by weight of diethylene glycol (DEG) at 200 to 230 ° C. in 100 parts by weight of terephthalic acid (TPA) A first mixing step of mixing;
A primary esterification step of esterifying the mixture of the first mixing step at 240 to 260 ° C. for 2 to 4 hours at 2.0 to 2.5 kgf / cm 2 pressure;
A second mixture of 5 to 90% by weight of the ethylene glycol (EG) 67 to 74 parts by weight, and 47 to 75 parts by weight of isophthalic acid (IPA) at 230 to 240 ° C. fair;
A secondary esterification step of esterifying the mixture of the second mixing step at 240 to 260 ° C. for 2 to 4 hours at 2.0 to 2.5 kgf / cm 2 pressure; And
A low melting point polyester short fiber manufacturing method, characterized in that the secondary ester reactant is produced by a polycondensation process of polymerization in a vacuum of 0.1 ~ 1 Torr or less for 275 ~ 285 ℃, 40 ~ 100 minutes. The method according to claim 11 or 12, wherein
The low melting point polyester short fiber manufacturing method, characterized in that the polymerization degree (Pn) of the low melting point polyester in the polycondensation step is polymerized to 60 ~ 90. The method according to claim 11 or 12, wherein
The low melting point polyester short fiber manufacturing method characterized in that the addition of phosphoric acid or phosphorus flame retardant in the polycondensation step. The method of claim 10,
The fiber manufacturing step,
A spinning process of spinning at low melting point polyester with a sheath and a general polyester with a core with a spinning speed of 1100-1500mpm at 250-290 ° C;
Low-melting polyester short-fiber manufacturing method characterized in that the fiber produced by the stretching step of stretching at a draw ratio of 2.0 to 4.0 in a 50 ~ 80 ℃ warm bath. 16. The method of claim 15,
The weight ratio of the sheath portion and the core portion is 40:60 to 70:30 crystalline low melting point polyester short fiber manufacturing method characterized in that. The method of claim 10,
The cutting step is a low-melting point polyester short fiber manufacturing method characterized in that to cut the low-melting point polyester fiber to 5 ~ 100mm.