TW201912864A - The compressing molding body using complex-fiber and manufacturing method thereof - Google Patents

Abstract

The present invention relates to a compression-molded body and a method for producing same, more specifically to a compression-molded body which is produced by compressing a fiber aggregate comprising binary composite fibers having superb moldability and form stability, and to a method for producing the compression-molded body.

Description

Compressed molded product and preparation method thereof

The present invention relates to a compression molded article excellent in morphological stability prepared by a fiber aggregate composed of bicomponent fibers and a process for producing the same.

In general, applications of fiber aggregates such as nonwovens have been used for various purposes such as sanitary, medical, agricultural or industrial purposes, and in particular, in the case of nonwoven fabrics for industrial purposes, tensile strength is very high. Important factor. In order to satisfy these requirements and obtain a product having high tensile strength, a method of increasing the weight per unit area is generally used. However, in the case where the weight is increased as described above, since the thickness of the product also increases at the same time, there is a problem that it is difficult to apply to a product requiring a small thickness and strength at the same time.

Therefore, the glass fiber, the carbon fiber, and the like are mixed and blended with other fibers to compensate for the insufficient mechanical properties of the application product using the fiber aggregate, so that a product having mechanical properties similar to or higher than that of the plastic product is manufactured. And sales. However, in the case of using such a glass fiber product, there is a problem that the glass fiber is detached from the product and scattered in the processing process to contaminate the working environment. Moreover, it has been reported that glass fibers cause lung cancer, and therefore, there is an increasing demand for the development of products having physical properties equivalent to or higher than those of products using glass fibers without using glass fibers. (Prior Art Document) (Patent Document) (Patent Document 1) Korean Patent No. 10-0899613 (Authorization Date: 2009. 5. 20) (Patent Document 2) Korean Patent No. 10-1357018 (Authorization Date: 2014) 01. 23)

Problems to be solved by the invention

The present invention has been made to solve the above problems, and an object of the present invention is to provide an excellent mechanical property such as tensile strength, bending strength, flexural modulus, and the like which is prepared using a fiber aggregate made of a specific bicomponent fiber. A good compression molded product such as sound absorbability, sound dispersibility, moisture absorbability, and water dispersibility, and a method for producing the above-described compression molded product having high commercial properties.

Solution to solve the problem

In order to achieve the above object, the compression-molded article of the present invention comprises a fiber aggregate layer formed by compressing a fiber aggregate composed of a single layer or a plurality of layers, the fiber aggregate comprising a two-component composite fiber, and the above-mentioned two-component composite fiber including poly Ester resin and crystalline polyolefin resin.

In a preferred embodiment of the present invention, in addition to the above two-component composite fiber, the above fiber aggregate may further comprise a binder fiber.

In a preferred embodiment of the invention, the fiber aggregate may be a dry-laid nonwoven fabric, a wet-laid nonwoven fabric or an air-laid. Nonwoven fabric.

In a preferred embodiment of the invention, the compression molded article may have an average areal density of from 600 to 1,500 g/m ² .

In a preferred embodiment of the invention, the uniformity of the average areal density of the compression molded article may be 2 to 5 CV%.

In a preferred embodiment of the present invention, in addition to the above fiber aggregate layer (first fiber aggregate layer), the compression molded product of the present invention may further comprise fibers comprising and constituting the above fiber aggregate layer (first fiber aggregate layer) A fiber aggregate layer (second fiber aggregate layer) of fibers of different components.

In a preferred embodiment of the present invention, the two-component composite fiber may include a first component resin and a second component resin, the first component resin may include a polyester resin, and the second component resin may include crystallinity. Polyolefin resin.

In a preferred embodiment of the present invention, the first component resin and the second component resin may have a melting point temperature difference of 30 to 100 °C.

In a preferred embodiment of the present invention, in the case of differential thermal analysis (DSC), the enthalpy value required for dissolving crystals of the above crystalline polyolefin resin may be 40 to 120 J/g.

In a preferred embodiment of the present invention, the first component resin may have an intrinsic viscosity of 0.50 to 1.00 dl/g and a melting point of 200 ° C or higher, and the first component resin may include a component selected from the group consisting of polyparaphenylene Polyethylene terephthalate (PET) resin, polybutylene terephthalate (PBT) resin, polytrimethylene terephthalate (PTT) resin and polyethylene naphthalate More than one polyester resin in a polyethylene naphthalate (PEN) resin.

In a preferred embodiment of the present invention, the polyethylene terephthalate resin may include a polymer obtained by polymerizing terephthalic acid and a diol (diol) in a molar ratio of 1:0.95 to 1.20.

In a preferred embodiment of the present invention, the second component resin may include one or more kinds of polyacrylic materials selected from polypropylene (polypropylene; PP) resin and polyethylene (PE) having a melting point of 150 to 170 ° C. Olefin resin.

In a preferred embodiment of the present invention, the two-component composite fiber may be a sheath-core type fiber, a side-by-side type fiber, a sea-island type fiber or a segmentation ( Segmented-pie) fiber.

In a preferred embodiment of the present invention, the cross-sectional area ratio of the first component and the second component of the two-component composite fiber may be 1:0.5-1.

In a preferred embodiment of the present invention, the two-component composite fiber may be a sheath-core type fiber, wherein the skin may include a crystalline polyolefin resin having a melting point of 150 to 170 ° C, and the core may include a melting point of 200 ° C or higher. Polyethylene terephthalate resin.

In a preferred embodiment of the present invention, when the bicomponent composite fiber is a sheath core fiber, the strength may be 3.5 g/d or more, the elongation may be 55% or more, and the initial elastic modulus may be 3.2 g/d. Above, the shrinkage rate may be 5.0 to 6.5%, and the number of crimps may be 9 to 15/inch.

In a preferred embodiment of the present invention, the two-component composite fiber may have an average fineness of 4 to 12 de, an average fiber length of 3 to 120 mm, and a crimp number of 9 to 15 per inch.

In a preferred embodiment of the invention, the surface of the bicomponent composite fiber described above may be modified, or a hydrophilic coating and/or a hydrophobic coating may be formed on the surface of the composite fiber.

In a preferred embodiment of the invention, the compression molded article of the present invention may have an average thickness of 2 to 5 mm.

In a preferred embodiment of the present invention, when measured at ASMT D790, the flexural strength of the compression molded article of the present invention may be 5.5 MPa or more at a relative humidity of 50% and a temperature of 23 ° C, and the bending modulus is It can be 430 MPa or more.

In a preferred embodiment of the present invention, the tensile strength of the compression molded article of the present invention may be 18.5 MPa or more at a relative humidity of 50% and a temperature of 23 ° C when measured based on ASMT D638.

Another object of the present invention relates to a method for producing a compression molded article described above, according to which a compression molded article can be produced by using a bicomponent composite fiber to prepare a fiber aggregate, and then the above fiber The aggregates are stacked into a single layer or a plurality of layers, which are then heat treated and compressed.

In a preferred embodiment of the invention, the fiber aggregates can be made by physical entanglement by a needle punching process.

In a preferred embodiment of the present invention, the fiber aggregate may be formed by forming a web in a paper machine by using a dispersion obtained by dispersing the above-mentioned two-component composite fiber in water, followed by drying. To prepare.

In a preferred embodiment of the invention, the heat treatment may be carried out at a temperature of 180 to 220 ° C for 1 to 5 minutes.

In a preferred embodiment of the invention, the compression can be carried out by a cold compression or a hot compression molding process.

In a preferred embodiment of the present invention, the two-component composite fiber may be prepared by a process comprising the steps of:

Step 1, preparing a polyester chip and a crystalline polyolefin chip, respectively;

Step 2, the first component resin and the second component resin respectively obtained by melting the polyester chip and the crystalline polyolefin chip are put into a composite spinning nozzle for composite spinning, and then the unstretched yarn is prepared by cooling. Sub-tow

Step 3, stretching the unstretched tow bundle, and then applying a crimp; and

In step 4, the stretched and crimped strands are heat set and cut.

In a preferred embodiment of the present invention, in the preparation of the two-component composite fiber, the above-mentioned split yarn may be a sheath-core type monofilament, a side-by-side type monofilament, an island-in-sea type monofilament or a split type monofilament.

In a preferred embodiment of the present invention, in the preparation of the two-component composite fiber, in step 2, the melting of the polyester chip can be carried out at a temperature of 270 to 300 ° C, and the melting of the crystalline polyolefin chip can be carried out at 230. It is carried out at a temperature of ~280 °C.

In a preferred embodiment of the present invention, in the preparation of the two-component composite fiber, in the step 2, the composite spinning can be performed at a spinning temperature of 260 to 290 ° C and a winding speed of 400 to 1,300 m / min. Go on.

Effect of the invention

The compression-molded article of the present invention is excellent in physical properties such as tensile strength, bending strength, and flexural modulus, and has excellent adhesion between the conjugated fibers and excellent workability, and therefore is suitable for application at the same time requiring high mechanical properties and sound. Products such as absorbency, sound dispersion, moisture absorption, and water dispersibility.

Next, the compression molded product of the present invention will be described in more detail.

The compression molded article of the present invention comprises a fiber aggregate layer (first fiber aggregate layer) which is obtained by compressing a fiber aggregate including a two-component composite fiber including a polyester resin and crystallizing Polyolefin resin.

The compression-molded article of the present invention may be composed of a single fiber aggregate layer as described above, or may have a multilayer structure in which a plurality of fiber aggregate layers are stacked.

In the compression molded product of the present invention, the above fiber aggregate may include only the above-described two-component composite fiber, or may further include a binder fiber.

In the present invention, the above fiber aggregate may be a dry-laid nonwoven fabric, a wet-laid nonwoven fabric or an air-laid nonwoven fabric, according to For the use of the compression molded article, various nonwoven fabrics can be applied.

Further, in addition to the above fiber aggregate layer (first fiber aggregate layer), the compression molded product of the present invention may further comprise fibers containing a component different from that of the fiber component constituting the above fiber aggregate layer (first fiber aggregate layer) Fiber aggregate layer (second fiber aggregate layer).

Further, the total thickness of the compression-molded article of the present invention may have an average thickness of 2 to 5 mm, preferably 2.5 to 4 mm, and more preferably 2.5 to 3.5 mm. The thickness of the compression molded product can be adjusted according to the specifications required for the product to be applied.

When the average thickness of the compression-molded article of the present invention described above is 3 mm (±0.1 mm), when measured based on ASMT D790, the bending strength may be 5.5 MPa or more in the case where the relative humidity is 50% and the temperature is 23 °C. And the bending elastic modulus may be 430 MPa or more, preferably, the bending strength may be 7.4 to 12 MPa and the bending elastic modulus may be 480 to 700 MPa, and more preferably, the bending strength may be 9.5 to 11.5 MPa and the bending elastic modulus may be 508 to 620 MPa. .

Further, in the case where the above-described compression molded article of the present invention has an average thickness of 3 mm (±0.1 mm), the compression molding of the present invention is carried out based on ASMT D638 at a relative humidity of 50% and a temperature of 23 °C. The tensile strength of the article may be 18.5 MPa or more, preferably 20 to 27 MPa, and more preferably 20.2 to 23.5 MPa.

Further, when the average thickness of the compression molded article of the present invention is 3 mm (±0.1 mm), the average areal density may be 600 to 1,500 g/m ² , and preferably 1,000 to 1,400 g / m ² . Further, the uniformity of the average areal density may be 2 to 5 CV%, and preferably may be 3 to 4.8 CV%.

The compression-molded article of the present invention as described above can be produced by, after using a two-component composite fiber to prepare a fiber aggregate, stacking the above-mentioned fiber aggregate into a single layer or a plurality of layers, followed by heat treatment and compression.

Wherein, the above fiber aggregate can be prepared by performing a conventional dry-laid nonwoven fabric manufacturing process in the art. Preferably, as a preferred embodiment, the two-component composite fiber can be made by physical interlacing through a needle punching process. .

Also, the above fiber aggregates can be prepared by performing a conventional wet-laid nonwoven fabric manufacturing process in the art, preferably, as a preferred embodiment, by performing the above-described two-component composite fiber by using in a paper machine. The dispersion is dispersed in water to form a paper web, which is then dried to prepare.

In the method for producing a compression molded product of the present invention, the heat treatment may be carried out at a temperature of 180 to 220 ° C for 1 to 5 minutes, preferably at a temperature of 190 to 210 ° C for 1 to 3 minutes.

Further, in the method for producing a compression molded article of the present invention, the above compression may be carried out by a molding process of cold compression or hot compression.

Next, a two-component composite fiber as a component of the fiber aggregate layer constituting the compression-molded article of the present invention will be described.

[Two-component composite fiber]

In the present invention, the above two-component composite fiber is a two-component composite fiber including a first component resin and a second component resin, and may be a sheath core fiber, a side-by-side fiber, an island-in-sea fiber or a split fiber. Preferably, it may be a sheath-core type fiber or a side-by-side type fiber.

The above-mentioned first component resin is related to the morphological stability of the fiber aggregate such as a nonwoven fabric and the compression molded article prepared using the fiber aggregate, and therefore, it is preferred to use a resin having an excellent modulus. Moreover, the second component resin preferably uses a material suitable for ensuring the morphological stability and moldability of the fiber aggregate and/or the compression molded article by ensuring adhesion to the composite fiber.

Further, in the above two-component composite fiber of the present invention, the melting temperature difference of the first component resin and the second component resin may be 30 to 100 ° C, preferably 40 to 90 ° C, at this time, If the difference in melting point temperature is less than 30 ° C, when the composite fiber is used to prepare the fiber aggregate, in order to achieve the bonding between the composite fibers by the second component resin, it is necessary to prepare the fiber aggregate under a suitable temperature atmosphere to make the second The component resin is appropriately melted, but since the temperature difference of the melting point between the first component resin and the second component resin is small and the first component resin becomes soft, it may cause fiber aggregates and compression molded articles using the fiber aggregates. The mechanical properties are lowered and the workability and formability are deteriorated. If the difference in melting point temperature is greater than 100 ° C, the temperature difference between the resins becomes unnecessarily large and the compatibility between the first component resin and the second component resin is rather lowered, so that it may be difficult to prepare a double group. The problem of sub-composite fibers.

The above first component resin may include a polyester resin, and the above polyester resin may include polyethylene terephthalate resin, polybutylene terephthalate resin, polytrimethylene terephthalate resin, and poly The naphthalate resin may preferably include one selected from the group consisting of polyethylene terephthalate resin, polybutylene terephthalate resin, and polyethylene naphthalate resin. Above, more preferably, a polyethylene terephthalate resin may be included.

Further, the polyester resin may have an intrinsic viscosity of 0.50 to 1.00 dl/g and a melting point of 200 ° C or higher. Preferably, the intrinsic viscosity may be 0.55 to 0.90 dl/g and the melting point may be 230 to 280 ° C, more preferably The intrinsic viscosity may be from 0.60 to 0.75 dl/g and the melting point may be from 240 to 265 °C. At this time, if the intrinsic viscosity of the polyester resin is less than 0.50 dl/g, there may be a problem that the toughness of the conjugate fiber is lowered, and if the intrinsic viscosity of the polyester resin is more than 1.00 dl/g, spinning and stretching work may exist. Reduced problems. Further, if the melting point of the polyethylene terephthalate resin is less than 200 ° C, the temperature difference between the melting points and the melting point of the second component resin becomes too small, and when the application product using the composite fiber is manufactured, there may be processing. The problem of lowering the properties, moldability, and the like is therefore preferable, and a polyethylene terephthalate resin having the above melting point is preferably used.

Further, when the polyester resin is a polyethylene terephthalate resin, a polyethylene terephthalate resin which is commonly used in the art can be used, and preferably, a mole including 1:0.95 to 1.20 can be used. A polyethylene terephthalate resin polymerized in a ratio of terephthalic acid and diol.

Next, the above second component resin may include a polyolefin resin.

The crystalline polyolefin resin may be one or more selected from the group consisting of a polypropylene resin and a polyethylene resin. Preferably, a polypropylene resin may be used.

Further, in the differential thermal analysis, the enthalpy value required for dissolving crystals of the above crystalline polyolefin resin may be 20 to 30 J/g, and preferably 22 to 28 J/g.

Further, the crystalline polyolefin resin may have a melting point of 150 to 170 ° C, preferably 155 to 170 ° C, and more preferably 160 to 170 ° C. In this case, if the melting point of the crystalline polyolefin resin is smaller than At 150 ° C, the temperature difference between the melting point and the polyester resin as the first component resin becomes too large, the spinnability for preparing the two-component composite fiber is lowered, and the first component resin and the second component are The compatibility between the resins is lowered, so that it is difficult to prepare the two-component composite fiber, and if the melting point of the crystalline polyolefin resin is more than 170 ° C, the temperature difference between the melting points of the first component resin and the second component resin becomes small. , resulting in a problem of reduced workability.

Moreover, the above two-component composite fiber is a composite fiber composed of two components, and the cross-sectional area ratio of the first component and the second component of the fiber may be 1:0.5 to 1, preferably, may be 1:0.7~ 1. At this time, if the cross-sectional area ratio of the second component is less than 0.5, there may be a problem that the bonding force between the composite fibers is lowered, and if the cross-sectional area ratio of the second component is more than 1, the area of the first component becomes It is relatively small, so the toughness of the composite fiber is lowered, and there may be a problem that the modulus of the product manufactured using the composite fiber is reduced.

In a preferred embodiment of the above two-component composite fiber, the composite fiber of the present invention may be a sheath-core type composite fiber, wherein the skin may include a crystalline polyolefin resin having a melting point of 150 to 170 ° C, and the core may include a melting point of Polyethylene terephthalate resin at 200 ° C or higher.

Moreover, the above two-component composite fiber may have an average fineness of 4 to 12 de, an average fiber length of 3 to 120 mm, a crimp number of 9 to 15 per inch, and preferably an average fineness of 5 to 10 de, and an average fiber. The length may be 6 to 100 mm, the number of crimps may be 10 to 14 per inch, and more preferably, the average fineness may be 5 to 9 de, the average fiber length may be 20 to 100 mm, and the number of crimps may be 10 to 14 per inch. At this time, if the average fineness of the composite fiber is less than 4 de, there may be a problem that the tensile strength of the fiber aggregate and/or the compression molded product is lowered. If the average fineness of the composite fiber is more than 12 de, there may be fiber aggregates and/or The problem of a decrease in the modulus of the compression molded product. Moreover, the fiber length of the composite fiber can be applied depending on the product change made using the composite fiber. Moreover, if the number of crimps is less than 9 / inch, the elasticity and bulkiness of the composite fiber may be deteriorated, and if the number of crimps is more than 15 / inch, there may be an increase in the neps during the carding process when preparing the fiber aggregate ( Nep) problem.

The above two-component composite fiber may impart functionality by modifying the surface of the fiber, or may form a hydrophilic coating and/or a hydrophobic coating on the surface of the composite fiber.

Moreover, the above-mentioned two-component composite fiber used in the present invention may have a toughness of 3.5 g/d or more, an elongation of 55% or more, an initial elastic modulus of 3.2 g/d or more, and a shrinkage ratio of 5.0 to 5. 6.5%, the number of crimps may be 9-15/inch. Preferably, the toughness of the above two-component composite fiber may be 3.70 to 4.10 g/d or more, and the elongation may be 57 to 62% or more, and the initial elastic modulus may be For 3.2~3.8g/d or more, the shrinkage rate can be 5.4~6.2%, and the curl number can be 10~14/inch.

The above two-component composite fiber may be prepared by a process comprising the steps of: step 1, preparing a polyester chip and a crystalline polyolefin chip, respectively; and step 2, respectively melting the polyester chip and the crystalline polyolefin chip The first component resin and the second component resin are put into a composite spinning nozzle for composite spinning, and then the unstretched filament bundle is prepared by cooling; in step 3, the unstretched filament bundle is pulled Stretching and then imparting curl; and step 4, heat setting and cutting the stretched and crimped strands.

The characteristics, kinds, and the like of the polyester chip of the above step 1 are the same as those of the first component resin as described above, and the characteristics, kinds, and the like of the above crystalline polyolefin chip and the second component as described above The characteristics, types, and the like of the resin are the same, and the above-mentioned polyester chip and crystalline polyolefin chip are formed by chip-forming the above-mentioned first component resin and second component resin.

In the step 2, the melting of the polyester chip can be carried out at a temperature of 270 to 300 ° C, and the melting of the crystalline polyolefin chip can be carried out at a temperature of 230 to 280 ° C.

The composite spinning in the step 2 can be carried out at a spinning temperature of 260 to 290 ° C and a winding speed of 400 to 1,300 m/min, preferably at a spinning temperature of 265 to 285 ° C and winding. The speed is 500~1,200m/min. At this time, if the spinning temperature is less than 260 ° C, there is a problem that the internal pressure of the pack increases and the spinning workability is lowered. When the spinning temperature is more than 290 ° C, there is a possibility that the physical properties of the composite fiber are lowered. Further, if the winding speed is less than 500 m/min, there may be a problem that the physical properties of the composite fiber and/or the application product to which the composite fiber is applied are lowered due to an increase in elongation, and if the winding speed is more than 1,300 m/min, Then there may be a problem that the stretch workability is lowered because the unstretched split strands are unevenly stacked on the can.

Further, the above-mentioned split tow of the step 2 may be a sheath-core type monofilament, a side-by-side type monofilament, an island-in-sea type monofilament or a split type monofilament.

The stretching in the step 3 can be carried out by a conventional stretching method in the art. Preferably, the unstretched yarn tow can be stretched to a temperature of from 70 to 100 ° C to 2.5 to 5 times, preferably, 3.0. ~4.5 times. In this case, if the draw ratio is less than 2.5 times, the physical properties of the applied product using the conjugate fiber may be lowered due to an increase in the elongation, and if the draw ratio is more than 5.0 times, the yarn breakage may occur, and therefore, it is preferable to Stretching is performed within the range.

Moreover, the curling in step 3 can be carried out by a conventional crimping method in the art. Preferably, as an example, a crimping box can be used to perform crimping by a crimp forming process which can stretch the stretched strands per 1 mm. Pass 3,000~8,000de.

Moreover, the step of performing a fixed length heat treatment process on the stretched split strands to increase the stability of the split strands may be further performed before the curling. As a specific example, a plurality of hot drums may be used to contact the filament bundle to the surface of the hot drum for about 5 to 30 seconds for heat treatment to increase the crystallinity of the filament bundle, thereby increasing the shrinkage rate and the modulus of elasticity.

The heat setting in step 4 can be carried out by a conventional heat fixing method in the art, preferably, as an example, after the stretched and crimped strands are placed in the oven at a temperature of 140 to 180 ° C. Preferably, it is carried out at a temperature of 140 to 170 ° C for 10 to 20 minutes. At this time, if the heat setting temperature is less than 140 ° C, there may be a problem that the shrinkage rate of the prepared final composite fiber increases. If the heat setting temperature is more than 180 ° C, there may be a decrease in the dispersibility of the composite fiber and the composite of the fiber aggregate. Since the fiber density is lowered and the workability is lowered, it is preferable to carry out heat setting at a temperature within the above range.

Moreover, the cutting in the step 4 is a process of cutting the heat-fixed filament bundle according to the processed product to be used with the composite fiber so that the composite fiber has a suitable fiber length, which can be carried out by a conventional cutting method in the art, preferably, The composite fiber was cut in such a manner that the average fiber length was in the range of 3 to 120 mm.

By the above production method, as described above, the composite fiber of the present invention having an average fineness of 4 to 12 de, an average fiber length of 3 to 120 mm, and a crimp number of 9 to 15 / inch can be prepared.

In the following, the present invention will be described in more detail with reference to the embodiments, however, the following examples should not be construed as limiting the scope of the invention.

[Examples]

Example 1: Preparation of sheath-core composite fiber

A polyethylene terephthalate resin chip having an intrinsic viscosity of 0.65 dl/g and a melting point of 252 ° C was prepared as a chip polyethylene terephthalate chip.

Further, a polypropylene resin in which a polypropylene resin having a enthalpy value of 94 J/g and a melting point of 165 ° C required for dissolving crystals at the time of differential thermal analysis was prepared was prepared.

Next, the above polyethylene terephthalate chip was melted at 290 ° C, and the polypropylene chip was melted at 260 ° C, and then the above two chips were put into a composite spinning nozzle to be spun and cooled to prepare. Core-core unstretched tow.

At this time, after the composite spinning was carried out under the conditions of a spinning temperature of 275 ° C and a winding speed of 950 m/min, it was loaded into a can by a suction machine process.

Next, the unstretched strands were drawn to 3.2 times at 85 ° C, and then subjected to a fixed length heat treatment at 150 ° C for 10 seconds.

Next, the stretched tow is crimped using a stuffing box.

Thereafter, the stretched and crimped strands were placed in an oven and heat-set at 165 ° C for 15 minutes to prepare a sheath-core composite having an average fineness of 7 de, an average fiber length of 51 mm, and a crimp number of 11 per inch. fiber. At this time, the cross-sectional area ratio of the sheath to the core was 1:1, wherein the sheath was composed of a polypropylene resin and the core was composed of a polyethylene terephthalate resin.

Example 2 to Example 12 and Comparative Examples 1 to 10

In addition to the following Tables 1 and 2, the polyethylene terephthalate chip as a core component, the polypropylene chip as a sheath component, the average fineness, the average fiber length, the number of crimps, and the cut of the sheath and core were changed. Except for the area ratio, each of the sheath-core type composite fibers was prepared in the same manner as in the above Example 1 to carry out Examples 2 to 12 and Comparative Examples 1 to 10. Table 1 Table 2

Experimental Example 1: Physical property measurement of composite fibers

The toughness, elongation, initial modulus of elasticity, and shrinkage ratio of the sheath-core type composite fibers prepared in the above Examples and Comparative Examples were measured based on the following methods, and the results are shown in Table 3 below. 1) Measurement methods of tenacity and elongation

The toughness and elongation of the fibers were measured using an automatic tensile tester (Textechno) at a speed of 50 cm/m and a clamping distance of 50 cm. The value obtained by dividing the fiber by applying a predetermined force to the fiber until the cutting is divided by the denier (g/de) is defined as the toughness, expressed as a percentage with respect to the initial length of the stretched length. The value (%) is defined as the elongation.

2) Initial elastic modulus and shrinkage measurement method

The initial modulus of elasticity was measured by a USTER TESTER, and the change in length of the composite fiber before and after the dry heat treatment at 180 ° C for 20 minutes was measured according to the following Mathematical Formula 1.

[Math 1]

Shrinkage (%) = (C-D) / C × 100%

In Mathematical Formula 1, C is the average value of the length of the fiber before the heat treatment, and D is the average value of the length of the fiber after the heat treatment. table 3

Referring to the physical properties of the composite fiber shown in Table 3 above, in the case of Examples 1 to 12, the toughness was 3.71 to 4.08 g/d, the elongation was 57.3 to 61.7%, and the initial modulus of elasticity was 3.3 to 3.6 g. /d, the shrinkage is 5.5 to 6.0%, and the number of crimps is 9.3 to 13.5/inch.

On the contrary, in the case of Comparative Example 1 in which the melting point of the sheath component was more than 170 ° C, there was a problem that the initial modulus of elasticity was less than 3.2 g/d, and in the case of Comparative Example 2 in which the melting point of the sheath component was less than 150 ° C, There is a problem of poor spinning, so the physical properties of the composite fiber cannot be measured.

Further, in the case of Comparative Example 3 in which polyethylene terephthalate having an intrinsic viscosity of more than 1.0 dl/g was used as the core component, the toughness and the elongation were lowered as compared with the examples.

Further, in the case of Comparative Example 5 in which the cross-sectional area ratio of the sheath and the core of the conjugate fiber was 1:0.45, that is, less than 1:0.5, there was a problem that the elongation was very poor.

Further, in the case of Comparative Example 7 in which the average fineness of the conjugate fiber was more than 12 de and Comparative Example 8 in which the average fineness was less than 4 de, the spinning was practically impossible.

Further, in the case of Comparative Example 9 in which the number of crimps was more than 16 / inch, there was a problem that the number of crimps was more than 15 / inch, that is, the number of crimps was too large, in the case of Comparative Example 10 in which the number of crimps was less than 9 / inch There is a problem that the number of curls is small.

Preparation Example 1: Preparation of a compression molded product

Only the composite fiber prepared in Example 1 was used for carding to prepare a needle-punched nonwoven fabric having a thickness of 10 mm.

Next, the above nonwoven fabric was heat-treated at 200 ° C for 90 seconds, and then cold-compressed to prepare a compression-molded article (average thickness of 3 mm).

The compression molded article thus prepared had an average areal density of 1,230 g/m ² and a uniformity of average areal density of 3 CV%.

Preparation Example 2: Preparation of a compression molded product

50% by weight of the conjugate fiber prepared in the above Example 1 and 50% by weight of 7 denier polyethylene terephthalate having a fiber length of 51 mm and an intrinsic viscosity of 0.65 dl/g were mixed and carded. A needled nonwoven fabric having a thickness of 10 mm was prepared.

Next, a heat-treated step and cold compression were carried out in the same manner as in the above Preparation Example 1 to prepare a compression-molded article (average thickness: 3 mm).

The compression molded article thus prepared had an average areal density of 1,250 g/m ² and a uniformity of average areal density of 4.6 CV%.

Preparation Example 3: Preparation of a compression molded product

70% by weight of the conjugate fiber prepared in the above Example 1 and 30% by weight of 7 denier made of polyethylene terephthalate having an intrinsic viscosity of 0.65 dl/g and a fiber length of 51 mm After the short fibers were mixed, carding was carried out to prepare a needle-punched nonwoven fabric having a thickness of 10 mm.

Next, a heat-treated step and cold compression were carried out in the same manner as in the above Preparation Example 1 to prepare a compression-molded article (average thickness: 3 mm).

The compression molded article thus prepared had an average areal density of 1,210 g/m ² and a uniformity of average areal density of 3.8 CV%.

Preparation Examples 4 to 14: Preparation of Compressed Shaped Articles

A needled nonwoven fabric having a thickness of 10 mm was prepared by the same method as that of the above Example 1 except that the composite fibers of Examples 2 to 12 were used instead of the composite fibers of Example 1.

Next, the nonwoven fabric was heat-treated at 200 ° C for 90 seconds, and then cold-compressed to prepare a compression-molded article (average thickness: 3 mm), thereby preparing Preparation Examples 4 to 14 (refer to Table 4 below).

Comparative preparation example 1

After mixing 60% by weight of 9 denier monofilament polypropylene fibers having a fiber length of 70 mm and 40% by weight of glass fibers, carding was carried out to prepare a needle-punched nonwoven fabric having a thickness of 10 mm.

Next, a heat-treated step and cold compression were carried out in the same manner as in the above Preparation Example 1 to prepare a compression-molded article (average thickness: 3 mm).

Comparative Preparation 2

4 denier polyethylene terephthalate binder fibers having a fiber length of 51 mm and a softening point of 110 ° C of 50% by weight and a fiber length of 50% by weight of 51 mm and an intrinsic viscosity of 0.65 dl/g. After the 7 denier short fibers made of polyethylene terephthalate were mixed, carding was carried out to prepare a needle-punched nonwoven fabric having a thickness of 10 mm.

Next, a heat-treated step and cold compression were carried out in the same manner as in the above Preparation Example 1 to prepare a compression-molded article (average thickness: 3 mm).

Comparative Preparations 3 to 9: Preparation of compression molded articles

A needled nonwoven fabric having a thickness of 10 mm was prepared by the same method as that of the above Example 1 except that the composite fibers of Comparative Examples 1 to 10 were used instead of the composite fibers of Example 1.

Next, the nonwoven fabric was heat-treated at 200 ° C for 90 seconds, and then cold-compressed to prepare a compression-molded article (average thickness of 3 mm), thereby performing Comparative Preparation Examples 3 to 9 (refer to Table 4 below). Table 4

Experimental Example 1: SEM measurement of compression molded product

The SEM photographs of the cut faces of the compression-molded articles prepared in Preparation Example 1, Preparation Example 2, and Preparation Example 3 are shown in Figs. 1 to 3, respectively.

As shown in the SEM measurement photograph of Fig. 1, in the case of the compression molded product of the present invention, the fibers are densely formed, and conversely, in the case of Preparation Example 2 and Preparation Example 3, as shown in Figs. 2 and 3 The fiber formation density is relatively low.

Experimental Example 2: Measurement of morphological stability of a compression molded product 1) Morphological stability according to temperature

After the compression molded product prepared in the above Preparation Example 1, Comparative Preparation Example 1 and Comparative Preparation Example 2 was placed in a hot air dryer, the mixture was aged for 1 hour while applying a load of 80 g, and then the morphology was confirmed. The result is shown in Fig. 4.

Referring to Fig. 4, it was confirmed that in the case of the compression molded product of Preparation Example 1, the morphological stability was also good at 100 ° C and 110 ° C, and in contrast, in the case of Comparative Preparation Examples 1 and 2, the morphology stability was observed. Reduced from 100 °C. 2) Measurement of morphological stability after aging in a heat-resistant environment

After the compression molded product prepared in the above Preparation Example 1, Comparative Preparation Example 1 and Comparative Preparation Example 2 was placed in a heat-resistant environment, the external force was removed, and then the morphological stability after 72 hours at 80 ° C was measured, and the results are shown in Figure 5.

Referring to Fig. 5, in the case of Preparation Example 1, there was no morphological change, but in the case of Comparative Preparation Example 1, the bending was largely performed, and Comparative Preparation Example 2 also showed a tendency to slightly warp at the end portion.

It was confirmed by measurement of the morphological stability that the compression molded product made of the conjugate fiber of the present invention is excellent in morphological stability.

Experimental Example 3: Tensile strength and modulus measurement of a compression molded product

The tensile strength, bending strength, and flexural modulus of the compression-molded articles prepared in Preparation Examples 1 to 14 and Comparative Preparation Examples 1 to 12 were measured, and the results are shown in Table 5 below.

At this time, the tensile strength was measured based on ASTM D 638, and the bending strength and the bending elastic modulus as the modulus were measured based on ASTM D 790.

Also, the uniformity refers to the standard deviation value at the time of measuring the average areal density. table 5

With reference to the above Table 5, it was confirmed that the tensile strength and modulus of the compression molded articles of Preparation Examples 1 to 14 were superior to those of Comparative Preparation Examples 1 and 2 as a whole, and in combination with polyethylene terephthalate. In Preparation Examples 2 to 3 of the ester fibers, Preparation Example 1 using fibers for compression molding alone exhibited relatively excellent mechanical properties.

Further, in the case of Comparative Preparation Example 3, there was a problem that the bending strength was slightly low and the workability was low. Further, in the case of Comparative Preparation Example 4, the bending elastic modulus was poor.

Further, in the case of Comparative Preparation Example 5, the bending strength was excellent, but the tensile strength was slightly lower. In the case of Comparative Preparation Example 6 and Comparative Preparation Example 7, there was a problem that the bending strength and the bending elastic modulus were too low.

Further, in the case of Comparative Preparation Example 8, there was a problem that a neps appeared due to the large number of crimps of the conjugate fibers used. In the case of Comparative Preparation 9, the flexural modulus was low because the number of crimps of the conjugate fiber used was too small.

From the above examples and experimental examples, it was confirmed that the conjugate fiber of the present invention has both excellent mechanical properties, sound absorbing properties, sound dispersibility, moisture absorbing properties, and water dispersibility. It is expected to provide various application products by forming the composite fiber of the present invention as described above into a fiber aggregate such as a nonwoven fabric or the like, and by way of example, the composite fiber of the present invention can be applied to construction. Internal and external materials, civil engineering materials, internal and external materials for transport units such as aircraft and ships, sanitary materials such as diapers, sanitary napkins and masks, and filters such as air filters and liquid filters.

A scanning electron microscope (SEM) photograph of a cross section of the compression-molded article prepared in Preparation Example 1 of Fig. 1 . SEM photograph of a cross section of the compression-molded article prepared in Comparative Preparation Example 1 of Fig. 2 . SEM photograph of a cross section of the compression-molded article prepared in Comparative Preparation Example 2 of FIG. 4 and 5 are morphological stability measurement results of Preparation Example 1, Comparative Preparation Example 1, and Comparative Preparation Example 2 which were carried out in Experimental Example 2, respectively.

Claims (15)

A compression molded product comprising a fiber aggregate layer formed by compressing a fiber aggregate composed of a single layer or a plurality of layers, wherein the fiber aggregate comprises a two-component composite fiber, and the two-component composite fiber comprises a polyester resin And crystalline polyolefin resin. The compression molded article according to claim 1, wherein the fiber aggregate further comprises a binder fiber. The compression-molded article according to claim 1, wherein the fiber aggregate is a dry-laid nonwoven fabric, a wet-laid nonwoven fabric or an air-laid nonwoven fabric. The compression-molded article according to claim 1, wherein the compression-molded article has an average areal density of 600 to 1,500 g/m ² . The compression molded article according to claim 4, wherein the uniformity of the average areal density is 2 to 5 CV%. The compression-molded article according to claim 1, wherein the two-component composite fiber is a sheath-core type fiber, a side-by-side type fiber, an island-in-sea type fiber, or a split type fiber. The compression molded article according to claim 1, wherein the polyester resin has an intrinsic viscosity of 0.50 to 1.00 dl/g and a melting point of 200 ° C or higher, and the polyester resin comprises a polyterephthalic acid selected from the group consisting of polyterephthalic acid. One or more of a glycol ester resin, a polybutylene terephthalate resin, a polytrimethylene terephthalate resin, and a polyethylene naphthalate resin, wherein the crystalline polyolefin resin includes a melting point selected from the group consisting of It is one or more of polypropylene resin and polyethylene of 120 to 170 °C. The compression molded product according to claim 1, wherein the two-component composite fiber is a sheath-core type fiber, wherein the skin is a crystalline polyolefin resin, and the core comprises a polyester resin, and the sheath-core fiber The average fineness is 4~12de, the average fiber length is 3~120mm, and the number of crimps is 9~15/inch. The compression-molded article according to claim 1, wherein the compression-molded article has an average thickness of 2 to 5 mm. The compression-molded article according to claim 1, wherein when the relative humidity is 50% and the temperature is 23° C., the bending strength is 5.5 MPa or more, and the bending elastic modulus is measured according to ASMT D790. 430MPa or more. The compression-molded article according to claim 1, wherein when the relative humidity is 50% and the temperature is 23° C., the tensile strength is 18.5 MPa or more when measured based on ASMT D638. A method for producing a compression molded product, characterized in that after the two-component composite fiber is used to prepare a nonwoven fiber aggregate, the fiber aggregate is stacked into a single layer or a plurality of layers, followed by heat treatment and compression. The method for producing a compression-molded article according to claim 12, wherein the fiber aggregate is physically entangled by a needling process. The method for producing a compression-molded article according to claim 12, wherein the fiber aggregate is formed into a paper web by using a dispersion obtained by dispersing the two-component composite fiber in water in a paper machine. Then, the drying step is carried out to prepare. The method for producing a compression molded article according to claim 12, wherein the two-component composite fiber comprises a polyester resin and a crystalline polyolefin resin, and the two-component composite fiber is a sheath core fiber and is side by side. Type fiber, island-type fiber or split fiber.