KR20180036627A - Short-cut fiber for the compressing molding body, Compressing molding body using the same and Manufacturing method thereof - Google Patents

Abstract

The present invention relates to a short-cut fiber for a compress-molded body, and a manufacturing method thereof. More specifically, the present invention provides a fiber aggregate and/or a compress-molded body excellent in bonding strength and compatibility with fibers and/or powder composed of a short-cut fiber and other components, and excellent in sound absorbency, sound dispersibility, water absorbability and water dispersibility.

Description

Technical Field [0001] The present invention relates to a short-cut fiber for a compression-molded body, a compression-molded body using the same, and a method for manufacturing the same,

The present invention relates to a short-cut fiber capable of providing an application product excellent in mechanical properties and excellent in sound and water-absorbing properties, a method of producing the short-cut fiber with high mass productivity, a compression molded article produced using the short- .

Generally, the application of a fibrous aggregate such as a nonwoven fabric has been used for a variety of purposes such as sanitary, medical, agricultural or industrial use. In particular, tensile strength is a very important factor in nonwoven fabrics used for industrial purposes, It is common to use a method of producing a product having a high tensile strength by increasing the weight per unit area. However, since the thickness of the product increases at the same time when the weight is raised, there is a problem that it is difficult to apply the product to a product requiring a small thickness and strength.

Fiber reinforced materials such as CFRP and GFRP, which have mechanical properties similar to or better than those of plastic products, are made by mixing inorganic fibers such as glass fiber and carbon fiber with other fibers, Composite materials are manufactured and sold. However, in the case of such a fiber-reinforced composite product, there is a problem that the working environment is contaminated because the glass fiber, carbon fiber, and the like are separated and scattered from the product in the processing process, and inorganic fibers such as glass fiber are known to cause lung cancer , There is an increasing demand for the development of products having properties equal or superior to the physical properties of products using glass fibers, without using glass fibers in recent years.

In order to prevent separation of inorganic fibers, a cover layer is formed on a product processed using a fiber reinforced composite material. In addition to being a cover for preventing separation of inorganic fibers, a cover layer And the number of researchers is increasing.

In addition, the types of noise sources such as vacuum cleaners, dishwashers, washing machines, air conditioners, air cleaners, computers, projectors, and the like are becoming more diverse, and the problem of noise pollution is becoming more serious. Therefore, efforts to block or reduce the noise generated from various noise sources in the modern life are continuing, and in the developed countries, the legal regulations to regulate the noise level between the interlayer and the generation of apartment houses and apartments are increasingly strict .

In addition, as the emotional quality of consumers has improved recently, the performance of NVH (noise, vibration, harshness) of automobiles, trains, and other transportation devices has become a demand of the times, and the demand of NVH related parts is rapidly increasing. Engine noise, which is generated in the engine and transmitted through the vehicle body or air, and friction noise between the wheels and the ground are representative examples of noise introduced into the interior of various transportation vehicles. In order to suppress such noise, an engine cover and a hood insulation are used. The application of sound absorption and sound insulating materials is expanding in parts requiring a large area.

Felt, sponge, polyurethane foam and the like are conventionally used as sound absorbing and sound insulating materials conventionally used. In addition, sound absorbing materials impregnated with thermoplastic resin or thermosetting resin in compressed fiber, glass fiber, rock surface, or regenerated fiber are listed . However, most of the sound absorbing materials described above have insufficient soundproofing ability, and most of the sound absorbing materials contain harmful components to the human body. Felt-type fiber materials used for various transportation interior and exterior materials are manufactured in a state in which they are physically entangled with binder fibers by using a dry nonwoven fabric manufacturing process. Such dry nonwoven fabrics are manufactured through a molding process, There is a problem that the manufacturing process is complicated and the economical efficiency is low.

In recent years, regulations on the environment-friendly and recyclability have been gradually strengthened, and the use ratio of the thermoplastic resin-based fiber-absorbing material is increasing. In order to reduce carbon dioxide, the regulation of fuel efficiency of the vehicle is gradually increasing. The improvement of fuel efficiency can be attained through the weight reduction of parts, so it is necessary to develop lightweight sound absorbing material with improved performance.

Accordingly, research and development on a sound absorbing material which is harmless to the human body and excellent in the sound absorbing function capable of effectively absorbing and reducing the noise while reducing the thickness has been actively conducted.

As a sound absorbing material that has been conventionally researched and developed, a sound absorbing material which is a web type in which general short fibers having a diameter of 10 탆 or more and which is crimped to a general meltblown fiber is contained in an amount of 10 wt% or more is disclosed (US Patent Publication No. 1954-433600). Further, a two-layer automotive sound absorbing material composed of a first sound-absorbing layer and a second sound-absorbing layer having different area densities has been invented, but there is a problem that the light-weighting is insufficient and the formability is poor.

Although a three-dimensional nonwoven web made of a meltblown microfine fiber is disclosed, a three-dimensional nonwoven web has a large porosity and thus is not densely structured, resulting in insufficient durability. It is necessary to increase the thickness of the three-dimensional nonwoven web significantly, and it is difficult to manufacture the nonwoven web composed of three dimensions as described above, which increases the manufacturing cost significantly. In addition, a sound absorbing material is also disclosed, which includes staple fibers that can be fused to the meltblown fibers by heat to impart three-dimensional stability. However, such a sound absorbing material still has a problem of insufficient sound insulation performance. In addition, a sound absorbing material using a honeycomb structure having a plurality of spaces together with meltblown fibers has been disclosed. However, such a sound absorbing material is insufficient in soundproof performance and has a problem in that it is limited in its application because of lack of flexibility.

Korean Patent No. 10-0899613 (Registered on May 20, 2009) Korean Registered Patent No. 10-1304879 (Registered on Mar. 09, 2013)

SUMMARY OF THE INVENTION The object of the present invention is to solve the above-mentioned problems, and an object of the present invention is to provide an application product such as a fiber aggregate having excellent mechanical properties and excellent sound absorption property, sound dispersion property, water absorption property and water dispersibility The present invention also provides a method for producing the short-cut fibers with high commercial efficiency.

Further, the fiber aggregate composed of the short-cut fibers having the short fiber length of three deniers can be processed into a compression-molded product having excellent elasticity due to a sufficient bonding force without using glass fibers, Products.

In order to solve the above-mentioned problems, the short fiber for a compression molded product of the present invention comprises a polymer obtained by polymerizing terephthalic acid and a diol in a molar ratio of 1: 1 to 1.25.

In one preferred embodiment of the present invention, the PET resin of the short-cut fiber for a compression-molded body of the present invention may have an intrinsic viscosity of 0.65 to 0.80 dl / g and a melting point of 250 to 260 ° C.

In one preferred embodiment of the present invention, the short fibers for the compression-molded body of the present invention may have an average fineness of 0.5 to 5 de and an average fiber length of 1 to 20 mm.

As a preferred embodiment of the present invention, the short-cut fibers for a compression-molded body of the present invention may have a strength of 3.5 to 7.0 g / d and an elongation of 20 to 50%.

In one preferred embodiment of the present invention, the short fiber for the compression molded article of the present invention may be one whose surface has been modified with a hydrophilic modifier or a hydrophobic modifier.

In one preferred embodiment of the present invention, the short fibers for the compression-molded body of the present invention may include a hydrophilic coating layer or a hydrophobic coating layer on all or part of the surface of the fibers.

As one preferred embodiment of the present invention, the short-cut fibers for a compression-molded body of the present invention may have a dry heat shrinkage of 2 to 6%.

Another object of the present invention is to provide a method for producing a short-cut fiber for a compression-molded body as described above, wherein a PET chip made of a polyethylene terephthalate (PET) resin is melted and radiated and then cooled to form an unstable sub- ); The short-cut fibers may be prepared by performing the two steps of: stretching the unstretched sub-tow under hot water and steam conditions, and heat-treating the cut, followed by cutting.

In one preferred embodiment of the present invention, the PET resin in Step 1 may include a polymer obtained by polymerizing terephthalic acid and a diol in a molar ratio of 1: 1 to 1.25.

In one preferred embodiment of the present invention, the melting in the first step may be performed at 270 ° C to 300 ° C.

In one preferred embodiment of the present invention, the spinning in the first step can be carried out at a spinning temperature of 275 to 295 DEG C and a spinning speed of 700 to 1,300 m / min.

In one preferred embodiment of the present invention, the two-step stretching can be performed such that the sub-tow is stretched at a temperature of 70 ° C to 90 ° C and the unstretched sub-sole is stretched to 2 to 4 times.

As a preferred embodiment of the present invention, the suit heat treatment may be performed at 160 ° C to 220 ° C.

As a preferred embodiment of the present invention, the dressing heat treatment may be performed using a hot drum or a heating roller.

As a preferred embodiment of the present invention, cutting in two steps can be performed by cutting the heat-set subtow to a short fiber having an average fiber length of 1 to 20 mm.

It is still another object of the present invention to provide a fiber aggregate composition for use in the production of a fiber aggregate using the short fiber for the compression-molded body of the present invention.

In one preferred embodiment of the present invention, the fibrous aggregate composition of the present invention comprises a dispersion containing the short-cut fibers, short-cut binder fibers and water of various types as described above; And a binder resin.

In one preferred embodiment of the present invention, the dispersion may contain 0.02 to 2% by weight of the short fiber, 0.001 to 1% by weight of the short-cut binder fiber, and residual water.

In one preferred embodiment of the present invention, the short-cut binder fiber may be a sheath-core binder fiber partially joining a plurality of the short-cut fibers.

In one preferred embodiment of the present invention, the short-cut binder fibers may have an average fineness of 1 to 12 de and an average fiber length of 3 to 30 mm.

In one preferred embodiment of the present invention, the sheath portion of the sheath-core binder fiber comprises polypropylene resin having a melting point of 155 DEG C to 185 DEG C, and the core portion has an intrinsic viscosity of 0.65 to 0.80 dl / g and a melting point of 250 DEG C to 260 DEG C PET resin.

In one preferred embodiment of the present invention, the binder resin may include 5 to 20 parts by weight based on 100 parts by weight of the total amount of the short-cut fibers and the short-cut binder fibers.

In one preferred embodiment of the present invention, the binder resin may include an acrylic binder resin.

Another object of the present invention is to provide a compression-molded article, wherein the compression-molded article of the present invention is obtained by compressing a laminate obtained by laminating a single layer or a multilayer of a wet- And extrudates.

In a preferred embodiment of the present invention, the laminate may further comprise a wet-type nonwoven fabric including fibers constituting the wet-laid nonwoven fabric and different kinds of fibers.

As a preferred embodiment of the present invention, the compression molded article of the present invention may have an average area density of 1,050 to 1,420 g / m ² when the thickness is 2 mm.

In a preferred embodiment of the present invention, the compression-molded article of the present invention may have a tensile strength of 19 to 25 MPa at a thickness of 2 mm and an average surface area of 1,150 to 1,250 g / m ² .

In a preferred embodiment of the present invention, the compression molded article of the present invention has a thickness of 2 mm and an average surface area of 1,150 to 1,250 g / m ² , and when measured according to ISO R 354 alpha cabin method, The absorption coefficient is 0.52 to 0.68 at 1,000 Hz, and the absorption coefficient is 0.55 to 0.75 at 2,000 Hz.

In a preferred embodiment of the present invention, the compression molded article of the present invention has a thickness of 2 mm and an average surface area of 1,150 to 1,250 g / m ² , and when measured according to ISO R 354 alpha cabin method, The absorption coefficient is 0.65 to 0.85 at 3,150 Hz, and the absorption coefficient is 0.80 to 0.95 at 5,000 Hz.

In one embodiment of the present invention, the compression-molded article of the present invention, and an average area density 2 ㎜ thickness of 1,150 ~ 1,250 g / m is ² one time, the transmission loss of 23.5 ~ 25.5 dB at 1,000 Hz, the transmission loss of 24.5 at 2,000 Hz To 27.8 dB, the transmission loss at 3,150 Hz is 32.0 to 40.0 dB, and the transmission loss at 5,000 Hz is 40.0 to 50.0 dB.

Still another object of the present invention is to provide a method for producing the above-mentioned compression molded article, comprising the steps of: preparing a dispersion by mixing the short fiber, short-cut binder fiber and water of the present invention described above; Mixing the dispersion and the binder resin to prepare a mixed solution; A third step of preparing a web in the paper making machine; Drying the web to produce a wet-laid nonwoven fabric; A fifth step of preparing a laminate in which the wet-laid nonwoven fabric is laminated in multiple layers, and then performing a heat treatment; 6) cold-compressing the heat-treated laminate; And 7) drying the cold compacted product to obtain a compression molded product.

In one preferred embodiment of the present invention, the drying in the four steps may be performed at 160 ° C to 190 ° C.

As a preferred embodiment of the present invention, the heat treatment in the six steps may be performed at 180 ° C to 220 ° C for 1 minute to 2 minutes.

It is still another object of the present invention to provide a fiber-reinforced composite material, a sound absorbing material, a sanitary material and / or a thermal insulation material using the above compression-molded article as an application product of the above-mentioned compression-molded article.

As a preferred embodiment of the present invention, the fiber-reinforced composite material and / or the sound absorbing material may be applied to electronic and electric devices such as an interior and exterior material of a transport machine, a refrigerator, and an air conditioner.

By controlling the shrinkage percentage of the short-cut fibers of the present invention to be low, the rate of dimensional change during the molding process of the fiber aggregate is small, and as a result, stable process passability and high commerciality can be exhibited. In addition, it has excellent bonding strength and compatibility with a fiber composed of components other than the short fiber component of the present invention and / or a powder composed of other components, and is excellent in workability as well as excellent in sound absorbency, sound dispersibility, It is suitable to be applied to a fiber aggregate in which acidity and the like are required, and a product of compression molding.

Fig. 1 is a photograph of the short fiber prepared in Example 1. Fig.
2 is an optical microscope photograph of the cross section of the short fiber prepared in Example 1. Fig.

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

The short-cut fibers for a compression-molded body of the present invention (hereinafter referred to as short-cut fibers) The PET resin has an intrinsic viscosity of 0.65 to 0.80 dl / g and a melting point of 250 to 260 ° C, preferably an intrinsic viscosity of 0.65 to 0.75 dl / g and a melting point of 252 to 256 ° C. If the intrinsic viscosity is less than 0.65 dl / g, there may be a problem that the spinning workability is poor and the physical properties are deteriorated. If the intrinsic viscosity is more than 0.80 dl / g, the workability in fiber formation is lowered, There is a problem that the manufacturing cost is increased.

The PET resin may be a polymer obtained by polymerizing terephthalic acid and diol in a molar ratio of 1: 1 to 1.25.

The short fibers of the present invention may have an average fineness of 0.5 to 5 de and an average fiber length of 1 to 20 mm, preferably an average fineness of 1 to 3 de and an average fiber length of 5 to 15 mm. If the mean fineness of the short fiber is less than 1 deg, the yield and the physical properties of the fiber aggregate may be deteriorated. If the average fineness exceeds 5 de, the number of short cuts constituting the fiber aggregate per unit weight is reduced, There may be a problem that the physical properties are deteriorated and the appearance becomes poor because the liver binding factor is decreased. If the average fiber length of the short fiber is less than 5 mm, there may be a problem that the bonding strength between fibers decreases. If the average fiber length exceeds 20 mm, the dispersibility decreases and the appearance and physical properties of the fiber aggregate deteriorate. Finally, There may be a problem.

In addition, the short fiber of the present invention may impart functionality by modifying the surface of the fiber with a hydrophilic modifier or a hydrophobic modifier, or all or part of the surface of the fiber may be imparted with functionality by forming a hydrophilic coating layer or a hydrophobic coating layer. More specifically, through the provision of such a function, the bonding strength and compatibility with a fiber composed of other components and / or a powder composed of other components may be further improved.

The short fiber of the present invention may have a strength of 3.5 to 7.0 g / d and an elongation of 20 to 50%, preferably a strength of 4.0 to 6.0 g / d and an elongation of 25 to 40%.

In addition, the short-cut fiber of the present invention may have a dry heat shrinkage of 2 to 6%, preferably 2 to 5%.

The short-cut fibers of the present invention can be obtained by a first step of preparing an unstretched sub-tow by melting and spinning a PET chip made of a polyethylene terephthalate (PET) resin and then cooling it; And 2) a step of cutting the unstretched sub tou after being subjected to stretching and dressing heat treatment under hot water and steam conditions, and then cutting.

The characteristics, kinds and the like of the PET resin in the first step are the same as those described above.

The melting in the first step can be carried out at 270 ° C to 300 ° C, preferably at 285 ° C to 295 ° C.

The spinning in the first step can be carried out under the conditions of the spinning temperature of 275 to 295 DEG C and the spinning speed of 700 to 1,300 m / min, preferably the spinning temperature of 280 to 290 DEG C and the winding speed of 800 to 1200 m / min. If the spinning temperature is less than 275 ° C, there may be a problem that the packing pressure rise and spinning workability are lowered. If the spinning temperature exceeds 295 ° C, the intrinsic viscosity of the PET resin is lowered and the physical properties of the short- There may be a problem of degradation. In addition, if the winding speed is less than 700 m / min, the stability of the unstretched sub-tow may be deteriorated and the elongation may increase to cause a problem that the properties of the short-cut fibers and / min, there is a problem that the unstretched sub tread is unevenly stacked on the can, resulting in a problem that the drawing workability is lowered.

The two-step stretching can be performed by a general method used in the art. Preferably, the unstretched sub-tow is stretched at a temperature of 70 ° C to 100 ° C, preferably 70 ° C to 90 ° C, And preferably 2.8 to 3.8 times. If the stretching ratio is less than 2.5 times, elongation increases and the physical properties of the applied product using the conjugate fiber may be reduced. If the stretching ratio exceeds 4, yarn splicing may occur. Therefore, good.

The two-stage dressing heat treatment is a step of increasing the stability of the sub-tow before crimping, and can be performed using a plurality of hot drums or heating rollers. As a concrete example, It is possible to increase the degree of crystallization of the sub-tow by increasing the degree of shrinkage and the modulus of elasticity.

The cutting can be carried out by a general cutting method used in the art so that the fiber has an appropriate fiber length according to a processed product to be used with the cutting fiber of the present invention. The average fiber length of the fiber is 1 to 20 mm, It is preferable to perform cutting within a range of preferably 2 to 15 mm.

With this manufacturing method, as described above, the short fiber of the present invention having an average fineness of 0.5 to 5 de and an average fiber length of 1 to 20 mm can be produced.

In addition, the short fiber of the present invention produced by the above-mentioned method may have a surface modified with a hydrophilic modifier or a hydrophobic modifier, or all or part of the surface of the fiber may form a hydrophilic coating layer or a hydrophobic coating layer.

A fiber aggregate such as a nonwoven fabric can be produced using the composite fiber of the present invention described above. At this time, the nonwoven fabric may be a wet-laid nonwoven fabric or an air-laid nonwoven fabric, preferably a wet nonwoven fabric. Such a composition used for producing a fiber aggregate includes a dispersion containing short-cut fibers, short-cut binder fibers and water; And a binder resin.

Here, the short-cut fibers have been described above.

The short-cut binder fiber may be a sheath-core binder fiber partially joining a plurality of the short-cut fibers.

The sheath portion of the short-cut binder fiber may include a polypropylene resin having a melting point of 155 ° C to 185 ° C, preferably a polypropylene resin having a melting point of 160 ° C to 175 ° C, more preferably a melting point of 160 ° C to 170 ° C , ≪ / RTI > At this time, when the melting point of the sheath is higher than 185 ° C, the sheath portion is not sufficiently dissolved in the drying process during the production of the nonwoven fabric, which is a fiber aggregate manufactured using the sheath portion, so that the short- The mechanical properties of the produced compression molded product may be deteriorated. If the melting point of the sheath is less than 155 占 폚, the sheath portion may become too melted during the drying step, resulting in a problem that the mechanical properties of the compression-molded body and / or the sound absorption sound may be deteriorated.

The core portion of the short-cut binder fiber contains a PET resin having an intrinsic viscosity of 0.65 to 0.80 dl / g and a melting point of 250 to 260 ° C, and preferably has a physical property and composition in the same range as that of the PET resin used for producing the short- PET resin is preferably used.

The short-cut binder fibers have an average fineness of 1 to 12 de and an average fiber length of 3 to 30 mm, preferably an average fineness of 1 to 6 de and an average fiber length of 3 to 25 mm, 4 de and an average fiber length of 3 to 18 mm is advantageous in terms of maintaining proper binder function for the short-cut fibers and improving the tensile strength and sound absorption characteristics of the compression-molded article.

The dispersion of the fiber aggregate composition may contain 0.02 to 2% by weight of the short cut fibers, 0.001 to 1% by weight of the short cut binder fibers, and the remaining water, preferably 0.02 to 1.5% by weight of the short cut fibers, 0.01 to 0.8% by weight, and balance water. If the content of short fiber is less than 0.02% by weight, the content of the short fiber may be too small to form an integrated web. If the fiber content is less than 0.02% by weight, the web may be formed well. However, There is a problem that the workability is deteriorated due to an increase in the number of fibers. If the content of the short-cut binder fiber is less than 0.001% by weight, the amount of the short-cut binder fibers used is too small, so that the bonding strength between the short-cut fibers decreases and the mechanical properties of the compression molded article may deteriorate. If the content is more than 1% by weight, It is preferable to use it within the above range.

The binder resin in the composition is used in an amount of 5 to 20 parts by weight, preferably 5 to 15 parts by weight, more preferably 5 to 10 parts by weight, based on 100 parts by weight of the total amount of short-cut fibers and short-cut binder fibers in the dispersion It is good. If the amount of the binder resin used is less than 5 parts by weight, it may be difficult to secure sufficient tensile strength of the compression molded body. If the binder resin is used in excess of 20 parts by weight, the tensile strength may be high. However, have.

The binder resin may be a common binder resin used in the art, preferably an acrylic binder resin.

Next, a method for producing the compression molded article of the present invention will be described.

The compression-molded article of the present invention comprises an extrudate obtained by compressing a laminate obtained by laminating a single-layer or multilayered wet-laid nonwoven fabric prepared by drying a web subjected to a paper-making machine with the above-mentioned fibrous aggregate composition, And may further include a wet nonwoven fabric including fibers and other kinds of fibers.

The compression-molded product of the present invention can be produced by the steps of: preparing a dispersion by mixing short-cut fibers, short-cut binder fibers and water; Mixing the dispersion and the binder resin to prepare a mixed solution; A third step of preparing a web in the paper making machine; Drying the web to produce a wet-laid nonwoven fabric; A fifth step of preparing a laminate in which the wet-laid nonwoven fabric is laminated in multiple layers, and then performing a heat treatment; And a sixth step of cold-compressing the heat-treated laminate.

In the first step, the composition and composition ratio of the dispersion, the characteristics of the composition, the dispersion used in the two-step mixed solution, and the composition and composition ratio of the binder resin are the same as described above.

The paper machine of the third step can use a general method used in the art.

The drying of the four-step is carried out at a temperature higher than the melting point of the polypropylene resin used in the sheath portion of the short-cut binder resin at 160 ° C to 190 ° C in the three-step web.

In step 5, the wet-laid nonwoven fabric thus prepared is laminated or interposed between two or more layers, preferably 5 to 20 layers, more preferably 5 to 15 layers, Heat treatment is performed at 220 캜 for 1 minute to 2 minutes, preferably 190 to 210 캜 for 1 minute to 2 minutes.

In the sixth step, the laminate of the fifth step can be cold-pressed by a general method used in the art to produce a compression molded article.

The compression molded product of the present invention may have an average area density of 1,050 to 1,420 g / m ² , preferably 1,100 to 1,350 g / m ² , more preferably 1,120 to 1,300 g / m ² , ² < / RTI >

The compression molded product of the present invention preferably has a tensile strength of 19 to 25 MPa at a relative humidity of 50% and 23 캜 under the conditions of a thickness of 2 mm and an average surface density of 1,150 to 1,250 g / m ² measured according to ASTM D638 , The tensile strength may be 19.5 to 24 MPa, and more preferably 20 to 23.5 MPa.

In addition, the compression-molded article of the present invention, thickness 2 ㎜ and an average area density 1,150 ~ 1,250 g / m ² be when, on the basis of the ASMT D790 under measurement and a relative humidity of 50% and 23 ℃, bending strength 7.5 ~ 12 Mpa, golgok modulus And may have a flexural strength of 8 to 11 Mpa and a skew elasticity of 470 to 580 Mpa, more preferably a flexural strength of 8.5 to 10.5 Mpa and a skew elasticity of 490 to 560 Mpa.

Then, the compression-molded article of the present invention, thickness 2 ㎜ and an average area density 1,150 ~ 1,250 g / m ² be when, as determined sound absorption coefficients on the basis of the alpha cabin (alpha cabin) method in ISO R 354, the sound absorption coefficient of 0.52 eseo 1,000 Hz To 0.68, preferably from 0.54 to 0.67, and more preferably from 0.55 to 0.65. Further, at 2,000 Hz, the absorption coefficient may be 0.55 to 0.75, preferably 0.56 to 0.74, and more preferably 0.59 to 0.74. Further, at 3,150 Hz, the absorption coefficient may be 0.65 to 0.85, preferably 0.68 to 0.80, and more preferably 0.70 to 0.80. Further, at 5,000 Hz, the absorption coefficient may be 0.80 to 0.95, preferably 0.82 to 0.94, and more preferably 0.85 to 0.93.

In addition, the compression-molded article of the present invention, and an average area density 2 ㎜ thickness of 1,150 ~ 1,250 g / m ² il time, the transmission loss is 23.5 eseo 1,000 Hz ~ 25.5 dB, preferably 23.8 ~ 25.2 dB, and more preferably 24.0 ~ 24.8 dB. Also, at 2,000 Hz, the transmission loss may be 24.5 to 27.8 dB, preferably 25.0 to 27.5 dB, and more preferably 25.0 to 27.0. In addition, the transmission loss at 3,150 Hz may be 32.0 to 40.0 dB, preferably 34.0 to 39.0 dB, more preferably 34.5 to 38.0 dB. The transmission loss at 5,000 Hz may be 40.0 to 50.0 dB, preferably 43.0 to 49.0 dB, and more preferably 45.0 to 48.5 dB.

Such a compression-molded article of the present invention may be applied as a cover layer of a processed product using a fiber-reinforced composite material containing inorganic fibers.

Further, the fiber aggregate and / or the compression-molded body using the short-cut fiber of the present invention has excellent mechanical properties, sound absorption / sound dispersibility and water absorption / water dispersibility, and can be used for building interior / exterior materials / A sanitary material such as a diaper, a sanitary napkin, a mask, etc., a filter such as an air filter or a liquid filter, and the like.

Hereinafter, the present invention will be described in more detail with reference to the following examples. However, the following examples should not be construed as limiting the scope of the present invention, and should be construed to facilitate understanding of the present invention.

[ Example ]

Example  1-1: For compression molded bodies Short-cut  Produce

A PET chip having an intrinsic viscosity of 0.65 dl / g and a melting point of 255 占 폚, which was made of a PET resin containing terephthalic acid and ethylene glycol as a diol at a molar ratio of 1: 1.2, was prepared.

Next, the PET chips were put into a spinneret and melted at 290 ° C, spinnable at a spinning temperature of 285 ° C and a spinning speed of 1,000 m / min, and then wound on a can through a winding process.

The untreated subtowel loaded in the can was stabilized after aging for 8 hours or more, and the canned water was prepared so that the total fineness could be 2 million denier.

Next, the unstretched-sub tow was stretched at a temperature of 80 캜 at a stretch ratio of 3.15, and then subjected to a suit heat treatment at 180 캜 for 20 seconds using a hot drum. As a result, the shrinkage rate of the PET short-cut fibers was controlled by adjusting the tension of the hot drum to 0.97 times for the first section and the third section for the entire four sections, and for the remaining sections to 1.0 time.

Cutting was then performed to produce short-cut fibers for compression-molded bodies having an average fineness of 1.5 denier (de) and an average fiber length of 12 mm, with a strength of 5.1 g / d and an elongation of 35%. The dry heat shrinkage rate was 2.8%. The prepared short-cut fibers are shown in Fig. 1, and their SEM cross-sectional photographs are shown in Fig.

Example  1-2 ~ Example  1-6 and Comparative Example  1-1 to 1-6

Short-cut fibers were prepared in the same manner as in Example 1-1, except that the types of PET chips or short fibers used in Table 1 were changed so as to produce short-cut fibers. Example 1-6 and Comparative Examples 1-1 to 1-6 were carried out.

The strength and elongation were measured in accordance with the method described in JIS L1013: 2010 under the conditions of a sample length of 100 mm and a tensile speed of 50 mm / min using an Instron universal tensile tester at ten times per level, The mean value was measured in terms of strength (g / denier) and elongation (%).

division PET chip Shortcut fiber Intrinsic viscosity
(dl / g) Melting point
(° C) Average fineness
(de) Fiber sheet
(mm) burglar
(g / d) Shindo
(%) Dry heat
Shrinkage rate
(%) Example 1-1 0.65 255 1.5 12 5.8 40 5.1 Examples 1-2 0.65 255 3.0 12 5.5 46 5.0 Example 1-3 0.65 255 1.0 12 5.8 41 4.9 Examples 1-4 0.65 255 1.5 17 5.8 40 5.1 Examples 1-5 0.65 255 1.5 2 5.8 40 5.1 Examples 1-6 0.72 258 1.5 12 6.1 38 5.0 Comparative Example 1-1 0.65 255 6.0 12 4.8 52 6.1 Comparative Example 1-2 0.65 255 0.4 12 No spinning Comparative Example 1-3 0.65 255 1.5 22 5.8 40 5.1 Comparative Example 1-4 0.65 255 1.5 0.9 5.8 40 5.1 Comparative Example 1-5 0.60 253 1.5 12 4.6 55 6.5 Comparative Example 1-6 0.82 262 1.5 12 No spinning

As a result of the test results shown in Table 1, it was confirmed that Examples 1-1 to 1-6 had appropriate physical properties at a strength of 5.5 to 6.1 g / d, an elongation of 38 to 46% and a dry heat shrinkage of 4.9 to 5.1% . On the other hand, in Comparative Example 1-1 in which the average fineness exceeded 6.0 de, there was a problem that the elongation exceeded 50%, and the short fiber of Comparative Example 1-2 having an average fineness of less than 0.5 de and the PET chip having too low intrinsic viscosity In the case of the short fiber of Comparative Example 1-5, there was a problem that the dry heat shrinkage ratio exceeded 6%.

Comparative Example 1-6 in which the average fineness exceeded 5de and Comparative Example 1-6 in which a PET chip having an intrinsic viscosity exceeding 0.80 dl / g were used, had problems in that spinning was not performed well in the production of short fiber.

Example  2-1: Shortcut  Manufacture of binder fibers

A polyethylene terephthalate (PET) resin having an intrinsic viscosity of 0.65 dl / g and a melting point of 255 캜 was prepared.

Further, a PP chip obtained by chipping a polypropylene (PP) resin having an enthalpy value of 94 J / g and a melting point of 165 DEG C necessary for dissolving the crystal was prepared in DSC (differential thermal analysis) analysis.

Next, the PET chips were melted at 290 ° C and the PP chips were melted at 260 ° C, and then they were put in a composite spinneret and spun, and then cooled to prepare cis-core type unoriented-subtowels.

At this time, the composite spinning was carried out at a spinning temperature of 275 ° C and a coiling speed of 950 m / min, and then, the composite spinning was carried out through the winding process and loaded on the can.

Next, the unstretched-sub tow was stretched 3.2 times at 85 캜, and then subjected to a suit heat treatment at 170 캜 for 20 seconds using a hot drum.

Next, cutting was carried out to prepare a cis-core short binder fiber for a binder having an average fineness of 2 denier and an average fiber length of 12 mm. The strength was 4.3 g / d, and the elongation was 50%. At this time, the cross sectional area ratio between sheath and core was 1: 1, the sheath was made of PP resin, and the core was made of PET resin.

Example  2-2 ~ Example  2-3 and Comparative Example  2-1 to 2-4

The cis-core short-cut binder fibers were produced in the same manner as in Example 2-1, except that the fibers were prepared by differentiating the sheath and core components from the following Table 2, Examples 2-1 to 2-4 were carried out.

division core
(PET resin) Cis
(PP resin) Sectional area ratio
(Sheath portion: core portion) Average fineness
(de) Fiber sheet
(mm) Intrinsic viscosity
(dl / g) Melting point
(° C) Melting point
(° C) Example 2-1 0.65 255 165 1: 1 2 12 Example 2-2 0.65 255 165 1: 1 2.5 15 Example 2-3 0.65 255 165 1: 1 4.0 10 Comparative Example 2-1 0.65 255 152 1: 1 2 12 Comparative Example 2-2 0.65 255 190 1: 1 2 12 Comparative Example 2-3 0.65 255 165 1: 1 7.5 12 Comparative Example 2-4 0.65 255 165 1: 1 2 32

Manufacturing example  One : Of the compression molded article  Produce

Next, the low shrinkage PET short fibers of Example 1-1 and the PP / PET short fibers of Example 2-1 were dispersed in water at a concentration of 0.04% by weight, respectively, to prepare a dispersion. Next, to 100 parts by weight of the shortcomb fiber, 7 parts by weight of an acrylic binder was added to the dispersion. Next, the dispersion was stirred and mixed to form a web in a paper machine. Next, the formed web was dried at 180 ° C to produce a wet-laid nonwoven fabric having an average area density of 100 g / m ² .

Next, ten nonwoven fabrics were laminated, heat-treated at 200 ° C for 90 seconds, and then cold-pressed to obtain a 1,200 g / m ² press-molded body (average thickness 2 mm).

Manufacturing example  2 to 8 and Comparative Manufacturing Example  1 to 8: Of the compression molded article  Produce

Production Examples 2 to 8 and Comparative Production Examples 1 to 10 were respectively carried out in the same manner as in Production Example 1 except that short-cut fibers or short-cut binder fibers were prepared in the same manner as in Table 3, .

division Shortcut
fiber Shortcut
bookbinder
fiber Web
dry
Temperature
(° C) Wet
Non-woven Compression molding body Average area density
(g / m ² ) Average thickness
(mm) Average area density
(g / m ² ) Production Example 1 Example 1-1 Example 2-1 180 100 2.0 1200 Production Example 2 Examples 1-2 180 99 2.0 1218 Production Example 3 Example 1-3 180 99 2.0 1175 Production Example 4 Examples 1-4 180 100 2.0 1192 Production Example 5 Examples 1-5 180 98 2.0 1207 Production Example 6 Examples 1-6 180 98 2.0 1181 Production Example 7 Example 1-1 Example 2-2 180 99 2.0 1227 Production Example 8 Example 2-3 180 101 2.0 1212 Comparative Preparation Example 1 Comparative Example 1-1 Example 2-1 180 102 2.0 1218 Comparative Production Example 2 Comparative Example 1-3 180 101 2.0 1200 Comparative Production Example 3 Comparative Example 1-4 180 102 2.0 1195 Comparative Production Example 4 Comparative Example 1-5 180 101 2.0 1230 Comparative Preparation Example 5 Example 1-1 Comparative Example 2-1 180 99 2.0 1196 Comparative Preparation Example 6 Comparative Example 2-2 180 102 2.0 1183 Comparative Preparation Example 7 Comparative Example 2-3 180 102 2.0 1225 Comparative Preparation Example 8 Comparative Example 2-4 180 98 2.0 1187

Experimental Example  : Of the compression molded article  Property measurement

The flexural modulus, bending strength, tensile strength, sound absorption performance, sound insulation performance and vibration damping property of the compression molded products produced in the above Production Examples and Comparative Production Examples were measured and the results are shown in Tables 5 and 6 below.

(1) Method of measuring flexural modulus and flexural strength

Flexural modulus and flexural strength were measured under ASMT D790 at 50% relative humidity and 23 캜.

(2) Tensile Strength (Load at Tensile Strength, MPa )

The tensile strength was measured in accordance with ASMT D638 at a relative humidity of 50% and 23 占 폚 after preparing a compression molded article having a size of 100 mm x 20 mm x 10 mm (width x length x height).

(3) Sound absorption coefficient measurement by frequency

Three compression molded bodies (1.2 m × 1.0 m (width × length)) were prepared for each of the specimens applicable to the ISO R 354, Alpha Cabin method for measuring the sound absorption coefficient, and left for 30 minutes at an external temperature of 0 ° C. and 25 ° C. The absorption coefficient was measured, and the measuring equipment used was Instron R.

(4) Measurement of transmission loss (dB) by frequency

The compression molded product was cut into 0.84 m × 0.84 m (length × length) to prepare samples, and permeation loss was measured using APAMAT-II (Autoneum).

(5) Mass production, workability, Operability  evaluation

The productivity was evaluated according to the method of evaluating the yield of the finished product which was judged to be good to the amount of the input raw materials, and the work performance and the workability were evaluated based on the calculation method of the occurrence frequency of the measures per hour. The evaluation results were evaluated comprehensively and expressed as " > > > >

division Manufacturing example One 2 3 4 5 6 Flexural modulus (Mpa) 520 530 500 510 490 520 Flexural Strength (Mpa) 9.9 10.4 9.3 9.8 9.1 9.7 Tensile Strength (Mpa) 22.1 21.5 22.8 22.3 20.4 22.5 Sound absorption performance
(Sound absorption coefficient) 1,000Hz 0.65 0.61 0.60 0.57 0.61 0.56 2,000Hz 0.72 0.71 0.62 0.67 0.69 0.64 3,150Hz 0.78 0.71 0.76 0.74 0.78 0.77 5,000Hz 0.91 0.89 0.86 0.90 0.88 0.83 Sound insulation performance
(Transmission loss,
dB) 1,000Hz 24.5 24.2 24.1 24.6 24.6 24.2 2,000Hz 25.9 25.8 25.7 25.2 26.7 26.6 3,150Hz 36.5 35.0 36.5 36.4 35.0 35.0 5,000Hz 46.9 46.1 45.7 45.5 46.7 45.9 Mass Production / Workability / Operation ◎ ◎ ○ ◎ ○ ○

division Manufacturing example Comparative Manufacturing Example 7 8 One 2 3 Flexural modulus (Mpa) 530 530 540 Non-woven fabric not available
(Poor dispersibility) 420 Flexural Strength (Mpa) 10.1 9.8 10.3 8.1 Tensile Strength (Mpa) 21.9 21.4 18.5 17.4 Sound absorption performance
(Sound absorption coefficient) 1,000Hz 0.55 0.57 0.58 0.56 2,000Hz 0.66 0.63 0.59 0.64 3,150Hz 0.71 0.75 0.72 0.73 5,000Hz 0.86 0.90 0.83 0.80 Sound insulation performance
(Transmission loss,
dB) 1,000Hz 24.9 24.1 23.8 23.9 2,000Hz 26.7 25.1 26.4 26.2 3,150Hz 35.1 35.2 35.3 34.1 5,000Hz 45.3 45.7 45.0 45.2 Mass Production / Workability / Operation ◎ ○ ○ △

division Comparative Manufacturing Example 4 5 6 7 8 Flexural modulus (Mpa) 430 420 380 490 Non-woven fabric not available
(Poor dispersibility Flexural Strength (Mpa) 8.4 8.3 7.6 8.9 Tensile Strength (Mpa) 17.8 17.1 16.2 18.1 Sound absorption performance
(Sound absorption coefficient) 1,000Hz 0.57 0.54 0.57 0.56 2,000Hz 0.61 0.66 0.70 0.64 3,150Hz 0.75 0.75 0.78 0.78 5,000Hz 0.86 0.86 0.88 0.80 Sound insulation performance
(Transmission loss,
dB) 1,000Hz 23.9 24.7 24.8 24.7 2,000Hz 26.3 26.8 26.9 26.6 3,150Hz 34.0 33.3 33.6 33.1 5,000Hz 44.2 44.5 44.6 44.6 Mass Production / Workability / Operation △ △ △ △

From the results of Tables 4 to 6, it was confirmed that the compression molded products of Production Examples 1 to 8 had excellent mechanical properties, sound absorption performance and sound insulation performance as a whole.

On the other hand, Comparative Production Example 1 using the short fibers of Comparative Example 1-1 had a problem of lowering tensile strength as compared with Production Example 1. [

In Comparative Production Example 2 using the short fibers of Comparative Example 1-3, the dispersibility of the short-cut fibers was poor and the production rate of the wet-laid nonwoven fabric was too high.

In addition, in Comparative Production Example 4 using short fibers of Comparative Production Examples 3 and 5 and Comparative Production Example 4 using Comparative Example 1-5, there was a problem that overall mechanical properties were significantly lower than those of Production Example .

In Comparative Production Examples 5 to 6 using the binder fibers of Comparative Examples 2-1 to 2-2, the mechanical properties of the compression molded product were poor. In Comparative Production Example 7 produced using the binder fibers of Comparative Example 3 There is a problem that the sound absorption performance at high frequencies is low. Also, in Comparative Production Example 7 using the binder fiber of Comparative Example 4, the fiber length was too long, so that the binder fibers were aggregated and the dispersibility was poor, which resulted in a problem that the percent defective of the wet nonwoven fabric was too high.

Through the above-mentioned Examples and Experimental Examples, it was confirmed that a compression molded body excellent in mechanical properties and excellent in sound and water absorbability can be produced by using the short fiber of the present invention. Such a compression molded article of the present invention can be applied to products such as automobile windows and other interior and exterior materials for vehicles, sound absorbing materials used for electric products and electronic products, and hygroscopic moisture absorbers.

Claims (20)

A polyethylene terephthalate (PET) resin comprising a polymer obtained by polymerizing terephthalic acid and a diol in a molar ratio of 1: 1 to 1.25.
The short fiber according to claim 1, wherein the PET resin has an intrinsic viscosity of 0.64 to 0.80 dl / g and a melting point of 250 to 260 ° C.
The short-cut fiber for a compression-molded body according to claim 1, wherein the average fineness is 0.5 to 5 de and the average fiber length is 1 to 20 mm.
The short-cut fiber for a compression-molded body according to claim 1, wherein the short-cut fiber has a strength of 3.5 to 7 g / d and an elongation of 20 to 50%.
The short-cut fiber for a compression-molded body according to claim 1, wherein the surface of the short fiber is modified with a hydrophilic modifier or a hydrophobic modifier.
The short fiber according to claim 1, wherein all or part of the surface of the short fiber includes a hydrophilic coating layer or a hydrophobic coating layer.
The short-cut fiber for a compression-molded body according to claim 1, wherein the dry heat shrinkage ratio is 2 to 6%.
A first step of melting and spinning a PET chip made of polyethylene terephthalate (PET) resin and then cooling to prepare an untreated sub-tow;
A second step of cutting the unstretched sub-tow by stretching and dressing heat treatment under hot water and steam conditions, and then cutting;
Wherein the short-cut fibers for the compression-molded body are made of a thermoplastic resin.
[9] The method according to claim 8, wherein the PET resin comprises a polymer obtained by polymerizing terephthalic acid and a diol in a molar ratio of 1: 1 to 1.25.
The method of producing a short-cut fiber for a compression-molded body according to claim 8, wherein the two-step stretching is conducted at a temperature of 70 ° C to 90 ° C at a stretching ratio of 2 to 4 times.
A dispersion comprising a short cut fiber, a short cut binder fiber and water according to any one of claims 1 to 7; And a binder resin.
12. The fiber aggregate composition according to claim 11, wherein the dispersion comprises 0.02 to 2% by weight of the short cut fibers, 0.001 to 1% by weight of the short cut binder fibers, and the balance water.
12. The fiber aggregate composition according to claim 11, wherein the binder resin is contained in an amount of 5 to 20 parts by weight based on 100 parts by weight of the total amount of the short-cut fibers and the short-cut binder fibers.
A nonwoven fabric comprising extrudates obtained by compressing a laminate obtained by laminating a wet nonwoven fabric as a single layer or multiple layers,
Wherein the wet-laid nonwoven fabric is produced by drying a web obtained by subjecting a paper-making machine to the fiber aggregate composition of claim 11.
A process for producing a dispersion by mixing short-cut fibers, short-cut binder fibers and water of any one of claims 1 to 7;
Mixing the dispersion and the binder resin to prepare a mixed solution;
A third step of preparing a web in the paper making machine;
Drying the web to produce a wet-laid nonwoven fabric;
A fifth step of preparing a laminate in which the wet-laid nonwoven fabric is laminated in multiple layers, and then performing a heat treatment;
6) cold-compressing the heat-treated laminate; And
And (7) drying the cold compact.
The method according to claim 15, wherein the drying in the fourth step is performed at 160 캜 to 190 캜,
Wherein the heat treatment in the step (6) is performed at a temperature of 180 ° C to 220 ° C for 1 minute to 2 minutes.
The method of claim 15 wherein the wet nonwoven fabric of the fourth step is the average area density is 70 ~ 140 g / m ^2,
Wherein the dried cold compact of step 7 has an average area density of 1,050 to 1,420 g / m < ² > when the thickness is 2 mm.
A fiber-reinforced composite material comprising the compression-molded body of claim 14.
An automotive interior and exterior material comprising the compression molded article of claim 14.
A sound absorbing material comprising the compression molded article of claim 14.

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