Polyester materials, methods of making and using the same

Abstract

The application relates to the field of high polymer materials, and discloses a polyester material, a preparation method and application thereof, wherein the average sound absorption coefficient of the polyester material is 0.61-0.95 under the condition of a frequency less than 1000 Hz, and the average sound absorption coefficient of the polyester material is 0.64-0.96 under the condition of a frequency greater than 5000 Hz; the size shrinkage rate of the polyester material is not higher than 3% in the temperature range of 0-215 DEG C. The preparation method comprises the following steps: (1) mixing a first polyester, a component a with a structural formula as shown in formula (I) and silicon dioxide, and then performing melt-blowing spinning to obtain first polyester melt-blown fibers; and (2) pre-treating fibers containing a second polyester, and then compounding the first polyester melt-blown fibers obtained in the step (1). The polyester material has good absorption to low-frequency, medium-frequency and high-frequency sound waves, has excellent sound absorption effect, has good heat resistance, has low production cost, and has remarkable economic benefits.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of high molecular materials, in particular to a polyester material and a preparation method and application thereof. BACKGROUND

[0002] With the vigorous development of industry, transportation and urban construction, noise pollution is becoming increasingly serious, and noise pollution has been listed as one of the four major global pollutions together with water pollution, air pollution and solid waste pollution. Studies have shown that noise not only causes hearing impairment, but also has adverse effects on the cardiovascular system, nervous system and endocrine system. Therefore, how to effectively prevent and control noise pollution is very important.

[0003] Automobiles, buildings, household and industrial electrical equipment, etc. will produce low-frequency noise. At present, most of the sound-absorbing materials used to block low-frequency noise are some high-gram-weight, high-thickness felt or high-density foam materials. These materials are easy to absorb water and mildew, have general medium-high frequency sound absorption efficiency, and some will produce toxic volatile gases in high-temperature use conditions.

[0004] At present, fiber-based porous sound-absorbing materials are most widely used. However, the traditional fiber-based sound-absorbing materials have limited sound absorption performance due to their coarse fiber diameter and large pore size, and can only rely on increasing density or thickness to improve sound absorption performance, which cannot meet the lightweight requirements of specific fields such as automobiles and aviation. Based on the shortcomings and deficiencies of traditional fiber-based sound-absorbing materials, it is of important application value to prepare a melt-blown composite ultra-fine fiber sound-absorbing material with three-dimensional fluffy structure and high, medium and low frequency wide frequency sound absorption. The melt-blown composite material has the advantages of simple processing technology, wide raw material sources and adjustable fiber structure, and is one of the most potential methods for preparing ultra-fine fiber sound-absorbing materials.

[0005] Chinese patent application with publication number CN104424941A provides a sound-absorbing material and a preparation method thereof. The sound-absorbing material comprises, from bottom to top, a PET sound-absorbing base material layer, an adhesive layer and a PP melt-blown non-woven fabric layer. The PET sound-absorbing base material layer is formed by hot bonding of 0.5-1.5 dtex PET fibers and low-melting-point PET fibers. The PET sound-absorbing cotton base material layer and the PP melt-blown non-woven fabric layer in the sound-absorbing material are combined by spraying polyethylene (PE) hot melt adhesive powder and then heated. The sound-absorbing material prepared has a sound absorption rate of 32.1-52.7% in the range of 250-6300 Hz. Although the product is a wide frequency sound-absorbing material, its sound absorption rate still needs to be improved. Moreover, the polypropylene and other materials used in the sound-absorbing material have low heat resistance temperature, which makes the sound-absorbing material have poor thermal stability at high temperature, thereby affecting its sound absorption performance.

[0006] CN105599400A discloses a kind of layered sound-absorbing material and its preparation method, the sound-absorbing material includes hot air cotton layer and heat-resistant fiber composite layer, the hot air cotton layer is obtained by low melting point polyester fiber, fine denier polyester fiber and ordinary polyester fiber carding, web laying, heat treatment;The heat-resistant fiber composite layer is the nonwoven material layer that is formed by one kind of heat-resistant fiber in polyphenylene sulfide fiber, poly (2, 6-dibromophenylene ether) fiber, meta-aramid fiber, heat-resistant fiber needs to be wet nonwoven processing and is obtained by at least one side calendering treatment under temperature 160-300 ℃, linear pressure 0.2-100 kgf / cm, continuous use temperature is 160-240 ℃;The upper and lower surface of the hot air cotton is attached to the heat-resistant fiber composite material, and the nonwoven material layer formed by heat-resistant fiber is attached to the hot air cotton layer at 90-180 ℃ by low melting point hot melt web film;The sound-absorbing material prepared by the method has complex processing technology and expensive heat-resistant fiber, although the heat-resistant performance is improved, the sound absorption coefficient is only 0.12-0.25 at low frequency 0-500Hz, and the low-frequency sound absorption efficiency is poor.

[0007] Therefore, it is urgent to provide a polyester material capable of heat resistance and wide-frequency sound absorption. SUMMARY

[0008] The purpose of the present application is to overcome the problems of poor wide-frequency sound absorption efficiency and poor heat resistance of the sound-absorbing material in the prior art, and to provide a polyester material, a preparation method and application thereof. The polyester material has good absorption to low-frequency, medium-frequency and high-frequency sound waves, excellent sound absorption effect, good heat resistance, low production cost and significant economic benefits.

[0009] To achieve the above-mentioned purpose, the first aspect of the present application provides a polyester material, the average sound absorption coefficient of which is 0.61-0.95 at a frequency less than 1000Hz, and the average sound absorption coefficient of which is 0.64-0.96 at a frequency greater than 5000Hz; the dimensional shrinkage rate of the polyester material is not higher than 3% at a temperature of 0-215 ℃.

[0010] The second aspect of the present application provides a preparation method of a polyester material, which comprises the following steps:

[0011] (1) mixing a first polyester, a component a with a structural formula as shown in formula (I) and silicon dioxide, and then melt-blowing to obtain a first polyester melt-blown fiber;

[0012]

[0013] wherein R1, R2, R3, R4, R5, R6, R7 and R8 are each independently hydrogen or C1-C4 alkyl, and n is an integer of 6-500;

[0014] (2) the fiber containing the second polyester is compounded with the first polyester melt-blown fiber obtained in step (1) after pretreatment.

[0015] The third aspect of the present application provides the use of the polyester material of the first aspect and / or the polyester material obtained by the preparation method of the second aspect in the preparation of sound-absorbing products.

[0016] Through the above technical solutions, the polyester material provided by the present application has the following beneficial effects:

[0017] The average sound absorption coefficient of the polyester material provided by the present application is 0.61-0.95 under the condition of a frequency less than 1000 Hz, and the average sound absorption coefficient is 0.64-0.96 under the condition of a frequency greater than 5000 Hz. The dimensional shrinkage rate of the polyester material is not higher than 3% in the temperature range of 0-215℃, which indicates that the polyester material has good absorption to low-frequency sound waves and high-frequency sound waves, and has excellent sound absorption effect and good heat resistance. The preparation method of the polyester material provided by the present application adds component a and silicon dioxide to the first polyester for melt-blown spinning. By improving the fluidity of the first polyester melt, the crystallization rate of the first polyester melt-blown fiber is controlled, and then the bonding degree of the first polyester melt-blown fiber and the fiber containing the second polyester is controlled. The porosity of the polyester material prepared can be adjusted, the sound absorption performance of the polyester material is improved, and at the same time, the polyester material has good thermal stability at high temperature and good heat resistance.

[0018] Other features and advantages of the present application will be described in detail in the subsequent specific embodiment part. BRIEF DESCRIPTION OF DRAWINGS

[0019] Figure 1 is a scanning electron microscope image of the polyester material prepared in Example 1;

[0020] Figure 2 is a scanning electron microscope image of the polyester material prepared in Example 2;

[0021] Figure 3 is a scanning electron microscope image of the polyester material prepared in Example 3;

[0022] Figure 4 is a scanning electron microscope image of the polyester material prepared in Example 4;

[0023] Figure 5 is a scanning electron microscope image of the polyester material prepared in Example 5;

[0024] Figure 6 is a scanning electron microscope image of the polyester material prepared in Example 6;

[0025] Figure 7 is a scanning electron microscope image of the polyester material prepared in Example 7;

[0026] Figure 8 This is a scanning electron microscope image of the polyester material prepared in Comparative Example 1;

[0027] Figure 9 This is a scanning electron microscope image of the polyester material prepared in Comparative Example 2;

[0028] Figure 10 This is a scanning electron microscope image of the polyester material prepared in Comparative Example 3. Detailed Implementation

[0029] The following provides a detailed description of specific embodiments of the present invention. It should be understood that the specific embodiments described herein are for illustrative and explanatory purposes only and are not intended to limit the scope of the invention.

[0030] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0031] The first aspect of this invention provides a polyester material, wherein the average sound absorption coefficient of the polyester material is 0.61-0.95 at frequencies below 1000Hz and 0.64-0.96 at frequencies above 5000Hz; and the dimensional shrinkage rate of the polyester material is no higher than 3% within a temperature range of 0-215℃. The polyester provided by this invention exhibits good absorption of both low-frequency and high-frequency sound waves, demonstrating excellent sound absorption performance. Furthermore, it possesses high thermal stability and good heat resistance at high temperatures.

[0032] In this invention, the average sound absorption coefficient is tested according to ISO 10534-2:1998 Measurement of sound absorption coefficient and specific impedance in acoustic impedance tubes - Part 2: Transfer function method.

[0033] In the present application, the process for testing the size shrinkage rate includes: cutting the polyester material of the present application into a 10cm*10cm block, placing it into a hot air oven with a preset temperature for 30min, taking out the polyester material after the time ends, measuring its size, and calculating the size shrinkage rate; changing the temperature of the hot air oven, and repeating the above experiment; wherein the preset temperature is 0-215℃. It should be noted that the size shrinkage rate of the polyester material in the temperature range of 0-215℃ is not higher than 3%, which means that in the temperature range of 0-215℃, the maximum value of the size shrinkage rate of the polyester material is not higher than 3%. According to the present application, preferably, the average sound absorption coefficient of the polyester material under the condition of a frequency of 1000-5000Hz is 0.74-0.96. The inventor found that under this preferred embodiment, the polyester material also has good absorption to medium and high frequency sound waves, indicating that the polyester material is a broadband sound absorption material.

[0034] In the present application, the polyester material has a loose structure and good porosity, and preferably, the porosity of the polyester material is 47-70%.

[0035] In the present application, the process for testing the porosity includes: converting the scanning electron microscope image of the polyester material of the present application into a black and white image using Photoshop software, and then using Matlab software to calculate the proportion of the black part in the black and white image to obtain the porosity of the polyester material.

[0036] The calculation program of the Matlab software is as follows:

[0037] i=imread('picture folder');

[0038] imshow(i);

[0039] sum(sum(i==0)) / numel(i).

[0040] According to the present application, preferably, the polyester material contains a first polyester, a second polyester, a component a with a structural formula as shown in formula (I), and silicon dioxide;

[0041]

[0042] wherein R1, R2, R3, R4, R5, R6, R7 and R8 are each independently hydrogen or C1-C4 alkyl, and n is an integer of 6-500. The inventor found that under this preferred embodiment, the polyester material containing a first polyester, a second polyester, a component a and silicon dioxide has good absorption to low, medium and high frequency sound waves, excellent sound absorption effect, and good heat resistance.

[0043] In the present application, R1, R2, R3, R4, R5, R6, R7 and R8 can be each independently hydrogen, hydroxyl, straight-chain alkyl or cycloalkyl, and can be specifically methyl, ethyl, n-propyl, isopropyl, cyclopropyl, n-butyl, isobutyl, tert-butyl or other possible C1-C4 alkyl.

[0044] According to the present application, preferably, R1, R2, R3, R4, R5, R6, R7 and R8 can be each independently selected from hydrogen, methyl and ethyl. For example, when R1, R2, R3, R4, R5, R6, R7 and R8 are all methyl, component a is polydimethylsiloxane; when R1 is hydrogen and R2, R3, R4, R5, R6, R7 and R8 are all methyl, component a is polymethylsiloxane; when R1, R2, R3, R4, R5, R6, R7 and R8 are all ethyl, component a is polydiethylsiloxane; when R1 is hydrogen and R2, R3, R4, R5, R6, R7 and R8 are all ethyl, component a is polyethylsiloxane.

[0045] According to the present application, the first polyester and the second polyester can be aromatic-aliphatic polyester or aliphatic-aromatic polyester, and in order to further improve the sound absorption effect of the polyester material, preferably, the first polyester and the second polyester are different, and each is independently selected from at least one of polybutylene terephthalate (PBT), polyethylene terephthalate (PET) and polytrimethylene terephthalate (PTT).

[0046] In the present application, the particle size of the silica is not particularly limited, and can be ordinary silica or nanoscale silica, and preferably, the average particle size of the silica is 100-3000 nm.

[0047] The above-mentioned substances can be obtained by commercial purchase or prepared by the preparation method disclosed in the prior art.

[0048] According to the present application, preferably, in the polyester material, the content of component a is 0.4-2.1 wt%, and the content of the silica is 0.4-2.1 wt%.

[0049] In the present application, component a in the polyester material can be measured by differential scanning calorimeter (DSC) and infrared spectrometer; further, the content of component a in the polyester material can be obtained by thermogravimetric analysis; high temperature is used to burn the ash of the polyester material, and the organic matter is burned and volatilized, and the remaining is inorganic matter, and the content of the inorganic matter is measured.

[0050] The second aspect of the present application provides a preparation method of a polyester material, which comprises the following steps:

[0051] (1) mixing the first polyester, component a with structural formula as shown in formula (I) and silicon dioxide, and then melt-blowing to obtain the first polyester melt-blown fiber;

[0052]

[0053] wherein R1, R2, R3, R4, R5, R6, R7 and R8 are each independently hydrogen or C1-C4 alkyl, and n is an integer of 6-500;

[0054] (2) pre-treating the fiber containing the second polyester, and then compounding the fiber with the first polyester melt-blown fiber obtained in step (1).

[0055] According to the present application, the preparation method of the polyester material is simple, suitable for industrial production, and has significant economic benefits. Moreover, the polyester material is obtained by directly compounding the first polyester melt-blown fiber and the fiber containing the second polyester, without using hot melt adhesive for compounding, so that no harmful gas is generated, which is environmentally friendly.

[0056] In the present application, R1, R2, R3, R4, R5, R6, R7 and R8 can each independently be hydrogen, hydroxyl, linear alkyl or cycloalkyl, and specifically can be methyl, ethyl, n-propyl, isopropyl, cyclopropyl, n-butyl, isobutyl, tert-butyl or other possible C1-C4 alkyl.

[0057] According to the present application, preferably, R1, R2, R3, R4, R5, R6, R7 and R8 can each independently be hydrogen, methyl and ethyl. For example, when R1, R2, R3, R4, R5, R6, R7 and R8 are all methyl, component a is polydimethylsiloxane; when R1 is hydrogen and R2, R3, R4, R5, R6, R7 and R8 are all methyl, component a is polymethylsiloxane; when R1, R2, R3, R4, R5, R6, R7 and R8 are all ethyl, component a is polydiethylsiloxane; when R1 is hydrogen and R2, R3, R4, R5, R6, R7 and R8 are all ethyl, component a is polyethylsiloxane.

[0058] According to the present application, preferably, component a can be polydimethylsiloxane. The inventors have found that in this preferred specific embodiment, component a can improve the flowability of the first polyester melt, thereby reducing the melt-blowing die temperature during melt-blowing, reducing production cost, and having significant economic benefits; moreover, the adhesion effect of the first polyester melt-blown fiber and the fiber containing the second polyester is improved, so that the polyester material has good thermal stability at high temperature and good heat resistance.

[0059] According to the present application, the first polyester and the second polyester can be aromatic-aliphatic polyester or aliphatic-aromatic polyester, and in order to further improve the sound absorption effect and heat resistance of the polyester material, preferably, the first polyester and the second polyester are different, and each is independently selected from at least one of polybutylene terephthalate (PBT), polyethylene terephthalate (PET) and polytrimethylene terephthalate (PTT). Further preferably, the first polyester is polybutylene terephthalate, and the second polyester is polyethylene terephthalate.

[0060] According to the present application, the particle size of the silica is not particularly limited, and can be ordinary silica or nanoscale silica, and preferably, the average particle size of the silica is 100-3000 nm. The inventors have found that in this preferred embodiment, the silica can adjust the crystallization rate of the first polyester melt-blown fiber, and by adjusting the adhesion degree of the first polyester melt-blown fiber and the fiber containing the second polyester, the porosity of the polyester material can be adjusted, thereby improving the sound absorption effect of the polyester material, and also making it have good heat resistance; in addition, the silica can improve the flowability of the first polyester melt, thereby reducing the melt-blown die temperature during melt-blown spinning, reducing production cost, and having significant economic benefits.

[0061] The above-mentioned substances can be obtained by commercial purchase or prepared by the preparation method disclosed in the prior art.

[0062] According to the present application, in order to further improve the flowability of the first polyester melt, preferably, the intrinsic viscosity of the first polyester is 0.50-1.00 dl / g, the melting point is 180-225℃, and the melt index under the condition of 190℃, 2.16 kg is 200-820 g / 10 min.

[0063] According to the present application, preferably, the weight ratio of the first polyester, the component a and the silica is 18-98:1:0.3-3. The inventors have found that in this preferred embodiment, by the synergistic effect of the component a and the silica, the flowability of the first polyester melt is further improved, thereby reducing the melt-blown die temperature during melt-blown spinning, reducing production cost, and improving the sound absorption effect and heat resistance of the polyester material.

[0064] In the present application, the melt-blowing method can adopt conventional means in the art, and preferably, the melt-blowing process comprises: mixing the first polyester, component a and the silica, and then inputting into a screw extruder, extruding and melting into a melt, and then extruding from the spinneret of the melt-blowing die, and then blowing at high speed in the nip of hot air at a certain temperature and speed, and stretching the fiber in the process. The spinning process can be adjusted according to the needs of the first polyester melt-blown fiber, for example, adjusting the melt-blowing die temperature, the drawing hot air temperature, the melt-blowing receiving distance (DCD distance), etc.

[0065] According to the present application, preferably, the melt-blowing conditions at least comprise: the melt-blowing die temperature is 240-290℃, and specifically can be 240℃, 250℃, 260℃, 270℃, 280℃, 290℃, or any value between the aforementioned two values; the melt-blowing receiving distance is 70-180mm, and specifically can be 70mm, 100mm, 150mm, 180mm, or any value between the aforementioned two values; the drawing hot air temperature is 260-290℃, and specifically can be 260℃, 270℃, 280℃, 290℃, or any value between the aforementioned two values.

[0066] According to the present application, preferably, the diameter of the first polyester melt-blown fiber is 2.0-3.0μm, and the crystallinity is 40-50%. The inventors have found that in this preferred specific embodiment, the bonding effect of the first polyester melt-blown fiber with the fiber containing the second polyester can be improved.

[0067] In the present application, the crystallinity is obtained by X-ray diffraction method, and the specific process comprises: cutting the first polyester melt-blown fiber into powder, then preparing a sample, and fixing it on the X-ray diffraction tester platform.

[0068] According to the present application, the fiber containing the second polyester can be a two-dimensional synthetic fiber, or a three-dimensional crimped hollow fiber. In order to further improve the elastic recovery performance and sound absorption effect of the polyester material, preferably, in step (2), the fiber containing the second polyester has a three-dimensional crimped hollow structure. The inventors have found that in this preferred specific embodiment, the polyester material prepared has the characteristics of being fluffy, soft and having good resilience.

[0069] According to the present application, in order to further improve the sound absorption effect and heat resistance of the polyester material, preferably, the fiber containing the second polyester has a fineness of 1-15dtex and a hollow rate of 20-35%.

[0070] The above-mentioned substances can be obtained by commercial purchase or prepared by the preparation method disclosed in the prior art.

[0071] According to the present application, the second polyester-containing fiber can have the same fineness or different fineness. In order to further improve the sound absorption effect and heat resistance of the polyester material, preferably, the second polyester-containing fiber contains at least one of a first fineness fiber, a second fineness fiber and a third fineness fiber; the first fineness fiber has a fineness greater than 1 dtex and less than or equal to 4 dtex, the second fineness fiber has a fineness greater than 4 dtex and less than 9 dtex, and the third fineness fiber has a fineness greater than or equal to 9 dtex and less than 15 dtex.

[0072] According to the present application, in order to further improve the sound absorption effect and heat resistance of the polyester material, preferably, the second polyester-containing fiber contains a first fineness fiber, a second fineness fiber and a third fineness fiber.

[0073] According to the present application, the amount of the second polyester-containing fiber of different fineness is not particularly limited. In order to further improve the sound absorption effect and heat resistance of the polyester material, preferably, the weight ratio of the first fineness fiber, the second fineness fiber and the third fineness fiber is 1:1-6:1-6.

[0074] According to the present application, preferably, the weight ratio of the second polyester-containing fiber to the first polyester melt-blown fiber is 0.4-2.5:1, specifically 0.4:1, 1:1, 1.5:1, 2:1, 2.5:1, or any value between the aforementioned two values. The inventors have found that in this preferred specific embodiment, the bonding effect of the second polyester-containing fiber and the first polyester melt-blown fiber is improved, the porosity of the polyester material is improved, and the sound absorption effect and heat resistance of the polyester material are further improved.

[0075] In the present application, the pretreatment method of the second polyester-containing fiber is not particularly limited, and the pretreatment method of the fiber commonly selected in the art can be used. Preferably, the pretreatment process includes: opening and carding the second polyester-containing fiber into a fiber web, and beating the fiber web. For example, the equipment used for pretreatment can be a cotton feeder, a coarse opener, a fine opener and a carding machine, and the specific process of pretreatment can include: forming a uniform cotton web after the second polyester-containing fiber is treated by the cotton feeder, the coarse opener, the fine opener and the carding machine, and then blowing the cotton web by a blowing machine.

[0076] According to the present application, the fibers containing the second polyester and the first polyester melt-blown fibers can be compounded in a manner selected from the art, preferably, the fibers containing the second polyester and the first polyester melt-blown fibers are compounded by thermal bonding, wherein the height difference between the air-laying machine and the melt-blown die is 30-80 mm. The inventors have found that in the preferred embodiment, the bonding effect between the fibers containing the second polyester and the first polyester melt-blown fibers can be improved, and thus the sound absorption effect and the heat resistance of the polyester material can be improved.

[0077] According to the present application, when the first polyester melt-blown fibers and the fibers containing the second polyester are subjected to thermal bonding, the temperature of the thermal bonding is related to the temperature of the first polyester melt-blown fibers after being discharged from the melt-blown die and the temperature of the drawing hot air, and preferably, the thermal bonding is performed under the conditions that the temperature is 240-290℃, and specifically, the temperature can be 240℃, 250℃, 260℃, 270℃, 280℃, 290℃, or any value between any two of the foregoing values; and the time is 5-60 s, and specifically, the time can be 5 s, 10 s, 20 s, 30 s, 40 s, 50 s, 60 s, or any value between any two of the foregoing values.

[0078] The third aspect of the present application provides the use of the polyester material of the first aspect and / or the polyester material prepared by the preparation method of the second aspect in the preparation of sound absorption products.

[0079] According to a particularly preferred embodiment of the present application, a preparation method of a polyester material is provided, and the method comprises the following steps:

[0080] (1) the fibers containing the second polyester are subjected to the processes of the air-laying machine, the coarse opener, the fine opener, and the carding machine to form a uniform web, and then the web is blown apart by the air-laying machine;

[0081] (2) the first polyester, component a, and silicon dioxide are mixed, and then melt-blown spinning is performed under the conditions that the die temperature is 240-290℃, the melt-blown receiving distance is 70-180 mm, and the drawing hot air temperature is 260-290℃, to obtain the first polyester melt-blown fibers;

[0082] (3) the fibers containing the second polyester are synchronously introduced into the first polyester melt-blown fibers which have not yet completely cooled, and the polyester material is compounded by thermal bonding under the condition that the height difference between the air-laying machine and the melt-blown die is 30-80 mm;

[0083] In the present application, component a is polydimethylsiloxane, the first polyester is polybutylene terephthalate, the second polyester is polyethylene terephthalate, the fibers containing the second polyester have a three-dimensional crimped hollow structure, and the average particle size of the silicon dioxide is 100-3000 nm.

[0084] In step (1), the intrinsic viscosity of the first polyester is 0.50-1.00 dl / g, the melting point is 180-225℃, and the melt index at 190℃ under the condition of 2.16 kg is 200-820 g / 10 min; the weight ratio of the first polyester, component a and silicon dioxide is 18-98:1:0.3-3; the diameter of the first polyester melt-blown fiber is 2.0-3.0 μm, and the crystallinity is 40-50%;

[0085] In step (2), the fiber containing the second polyester has a three-dimensional crimped hollow structure; the fiber containing the second polyester has a fineness of 1-15 dtex and a hollow rate of 20-35%; the fiber containing the second polyester contains first fineness fiber, second fineness fiber and third fineness fiber, the first fineness fiber has a fineness greater than 1 dtex and less than or equal to 4 dtex, the second fineness fiber has a fineness greater than 4 dtex and less than 9 dtex, and the third fineness fiber has a fineness greater than or equal to 9 dtex and less than 15 dtex, and the weight ratio of the first fineness fiber, the second fineness fiber and the third fineness fiber is 1:1-6:1-6; the weight ratio of the fiber containing the second polyester and the first polyester melt-blown fiber is 0.4-2.5:1.

[0086] In the above preferred embodiment, the polyester material prepared can better absorb low-frequency, medium-frequency and high-frequency sound waves, has excellent sound absorption performance, good heat resistance, and reduced production cost, and has significant economic benefits.

[0087] The application will be described in detail below with reference to the examples, but the scope of the application is not limited thereto.

[0088] In the following examples and comparative examples, all raw materials are commercially available.

[0089] The average sound absorption coefficient is tested according to ISO 10534-2:1998 Acoustics-Determination of sound absorption coefficient, absorption of sound in a reverberation room-Part 2: Measurement of the normal incidence coefficients of a surface by the surface test method.

[0090] The porosity process includes: converting the scanning electron microscope image of the polyester material into a black and white image using Photoshop software, and then using Matlab software to calculate the proportion of the black part in the black and white image to obtain the porosity of the polyester material.

[0091] The Matlab software calculation program is as follows:

[0092] i = imread ('picture folder');

[0093] imshow (i);

[0094] sum (sum (i == 0)) / numel (i).

[0095] The test process of the size shrinkage rate comprises: cutting the polyester material into a 10 cm x 10 cm block, placing the polyester material into a hot air oven with a fixed temperature for 30 minutes, taking out the polyester material after the time ends, measuring the size of the polyester material, and calculating the size shrinkage rate; the temperature of the hot air oven is changed, and the above experiment is repeated; wherein the temperature is 0-215 DEG C.

[0096] The crystallinity is obtained according to the X-ray diffraction method, and the specific process comprises: cutting the first polyester melt-blown fiber into powder, then preparing a sample, and fixing the sample on an X-ray diffraction tester platform.

[0097] Example 1

[0098] (1) Three-dimensional crimped hollow PET fibers with fineness of 2.78 dtex, 6.67 dtex and 14.44 dtex respectively are mixed in a mass ratio of 10:60:30, the mixed fibers are processed by a cotton feeder, a coarse opener, a fine opener and a carding machine to form a uniform cotton web, and then the cotton web is blown away by a blowing machine;

[0099] (2) PBT melt-blown fibers are obtained by melt-blown spinning using a mixture of PBT melt-blown material with a specific viscosity of 0.70 dl / g, a melting point of 218 DEG C and a melt index of 700 g / min, and polydimethylsiloxane with a molecular weight of 41600 and silica with an average particle size of 500 nm (mass ratio of 96:2:2), the main melt-blown process is that the die temperature is 270 DEG C, the melt-blown receiving distance is 100 mm, and the drawing hot air temperature is 290 DEG C;

[0100] (3) The three-dimensional crimped hollow PET mixed fibers in step (1) are synchronously fed into the PBT melt-blown fibers which have not yet completely cooled, the mass ratio of the three-dimensional crimped hollow PET mixed fibers to the PBT melt-blown fibers is 60:40, and the three-dimensional crimped hollow PET mixed fibers and the PBT melt-blown fibers are compounded by using thermal bonding, so as to prepare a polyester material; wherein the height difference between the outlet of the blowing machine and the melt-blown die is 50 mm.

[0101] The scanning electron microscope graph of the polyester material prepared in Example 1 is shown in Figure 1 .

[0102] Example 2

[0103] (1) Three-dimensional crimped hollow PET fibers with fineness of 1.33 dtex, 6.67 dtex and 14.44 dtex respectively are mixed in a mass ratio of 20:50:30, the mixed fibers are processed by a cotton feeder, a coarse opener, a fine opener and a carding machine to form a uniform cotton web, and then the cotton web is blown away by a blowing machine;

[0104] (2) PBT meltblown material with intrinsic viscosity of 0.70 dl / g, melting point of 218 °C and melt index of 700 g / min is used to meltblown spinning with a mixture of polydimethylsiloxane with molecular weight of 36200, silica with average particle size of 880 nm (mass ratio of 96:2:2) to obtain PBT meltblown fibers, the main meltblown process: die temperature is 270 °C, meltblown receiving distance is 100 mm, and drawing hot air temperature is 290 °C.

[0105] (3) The three-dimensional crimped hollow PET mixed fibers in step (1) are synchronously fed into the PBT meltblown fibers which have not yet completely cooled, and the mass ratio of the three-dimensional crimped hollow PET mixed fibers to the PBT meltblown fibers is 30:70, and the three-dimensional crimped hollow PET mixed fibers and the PBT meltblown fibers are compounded by using thermal bonding to prepare a polyester material; wherein the height difference between the outlet of the blowing machine and the meltblown die is 50 mm.

[0106] The scanning electron microscope image of the polyester material prepared in Example 2 is shown in Figure 2 .

[0107] Example 3

[0108] The polyester material is prepared according to the method of Example 2, except that in step (2), the mass ratio of PBT meltblown material, polydimethylsiloxane and silica is replaced by 96:3:1.

[0109] The scanning electron microscope image of the polyester material prepared in Example 3 is shown in Figure 3 .

[0110] Example 4

[0111] The polyester material is prepared according to the method of Example 2, except that in step (2), the mass ratio of PBT meltblown material, polydimethylsiloxane and silica is replaced by 96:1:3.

[0112] The scanning electron microscope image of the polyester material prepared in Example 4 is shown in Figure 4 .

[0113] Example 5

[0114] (1) Three-dimensional crimped hollow PET fibers with fineness of 2.78 dtex, 6.67 dtex and 14.44 dtex respectively are mixed in a mass ratio of 10:60:30, and the mixed fibers are processed by a cotton feeder, a coarse opener, a fine opener and a carding machine to form a uniform cotton web, and then the cotton web is blown away by a blowing machine;

[0115] (2) PBT meltblown fiber was prepared by meltblowing spinning using a mixture of PBT meltblown material with intrinsic viscosity of 0.50 dl / g, melting point of 180℃ and melt index of 820 g / min, and a mixture of polydimethylsiloxane with molecular weight of 45200 and silica with average particle size of 100 nm (mass ratio of 98:1:1), main meltblowing process: die temperature of 240℃, meltblown receiving distance of 100 mm, drawing hot air temperature of 260℃;

[0116] (3) The three-dimensional crimped hollow PET mixed fiber in step (1) was synchronously fed into the PBT meltblown fiber which had not yet completely cooled, and the mass ratio of the three-dimensional crimped hollow PET mixed fiber to the PBT meltblown fiber was 60:40, and the three-dimensional crimped hollow PET mixed fiber and the PBT meltblown fiber were compounded by using thermal bonding, thereby preparing a polyester material; wherein the height difference between the outlet of the blowing machine and the meltblowing die was 50 mm.

[0117] The scanning electron microscope image of the polyester material prepared in Example 5 is shown in Figure 5 .

[0118] Example 6

[0119] (1) The three-dimensional crimped hollow PET fibers with fineness of 2.78 dtex, 6.67 dtex and 14.44 dtex were mixed in a mass ratio of 10:60:30, and the mixed fibers were processed by a cotton feeder, a coarse opener, a fine opener and a carding machine to form a uniform cotton web, and then the cotton web was blown away by a blowing machine;

[0120] (2) PBT meltblown fiber was prepared by meltblowing spinning using a mixture of PBT meltblown material with intrinsic viscosity of 1.0 dl / g, melting point of 225℃ and melt index of 200 g / min, and a mixture of polydimethylsiloxane with molecular weight of 7380 and silica with average particle size of 1300 nm (mass ratio of 90:5:5), main meltblowing process: die temperature of 270℃, meltblown receiving distance of 100 mm, drawing hot air temperature of 290℃;

[0121] (3) The three-dimensional crimped hollow PET mixed fiber in step (1) was synchronously fed into the PBT meltblown fiber which had not yet completely cooled, and the mass ratio of the three-dimensional crimped hollow PET mixed fiber to the PBT meltblown fiber was 60:40, and the three-dimensional crimped hollow PET mixed fiber and the PBT meltblown fiber were compounded by using thermal bonding, thereby preparing a polyester material; wherein the height difference between the outlet of the blowing machine and the meltblowing die was 50 mm.

[0122] The scanning electron microscope image of the polyester material prepared in Example 6 is shown in Figure 6 .

[0123] Example 7

[0124] (1) Three-dimensional crimped hollow PET fibers with fineness of 3.33 dtex and 8.89 dtex respectively were mixed in a mass ratio of 40:60, and the mixed fibers were processed by a cotton feeder, a coarse opener, a fine opener and a carding machine to form a uniform cotton web, and then the cotton web was blown apart by a blowing machine.

[0125] (2) PBT melt-blown fibers were obtained by melt-blown spinning using a PBT melt-blown material with intrinsic viscosity of 0.70 dl / g, melting point of 218℃ and melt index of 700 g / min, and a mixture of polydimethylsiloxane (PDMS) with molecular weight of 23600 and silica with average particle size of 3000 nm (mass ratio of 96:2:2), the main melt-blown process: die temperature of 270℃, melt-blown receiving distance of 100 mm, and hot air temperature of 290℃.

[0126] (3) The three-dimensional crimped hollow PET mixed fibers in step (1) were synchronously fed into the PBT melt-blown fibers which were not completely cooled, and the mass ratio of the three-dimensional crimped hollow PET mixed fibers to the PBT melt-blown fibers was 50:50, and the three-dimensional crimped hollow PET mixed fibers and the PBT melt-blown fibers were compounded by using thermal bonding, thereby preparing a polyester material; wherein the height difference between the outlet of the blowing machine and the melt-blown die was 50 mm.

[0127] The scanning electron microscope graph of the polyester material prepared in Example 7 is shown in Figure 7 .

[0128] Example 8

[0129] The polyester material was prepared according to the method of Example 1, except that step (1) was replaced by:

[0130] (1) Three-dimensional crimped hollow PET fibers with fineness of 6.67 dtex were processed by a cotton feeder, a coarse opener, a fine opener and a carding machine to form a uniform cotton web, and then the cotton web was blown apart by a blowing machine.

[0131] Example 9

[0132] The polyester material was prepared according to the method of Example 1, except that in step (2), the polydimethylsiloxane was replaced by polydiethylsiloxane with a molecular weight of 12000.

[0133] Example 10

[0134] The polyester material was prepared according to the method of Example 1, except that in step (2), the silica was replaced by silica with an average particle size of 15 μm.

[0135] Example 11

[0136] The polyester material was prepared according to the method of Example 2, except that in step (2), the PBT melt-blown material was replaced by PBT melt-blown material with an intrinsic viscosity of 1.2 dl / g, a melting point of 225 °C, and a melt index of 150 g / min.

[0137] Example 12

[0138] The polyester material was prepared according to the method of Example 2, except that in step (2), the mass ratio of PBT melt-blown material, polydimethylsiloxane (PDMS), and nano-sized silicon dioxide was replaced by 85:10:5.

[0139] Example 13

[0140] The polyester material was prepared according to the method of Example 2, except that in step (3), the mass ratio of three-dimensional crimped hollow PET mixed fibers and PBT melt-blown fibers was replaced by 20:80.

[0141] Example 14

[0142] The polyester material was prepared according to the method of Example 2, except that step (1) was replaced by:

[0143] (1) The two-dimensional PET fibers were processed through a cotton feeder, a coarse opener, a fine opener, and a carding machine to form a uniform cotton web, and then the cotton web was blown apart by a blowing machine.

[0144] Comparative Example 1

[0145] The polyester material was prepared according to the method of Example 3, except that in step (2), no silicon dioxide was added, and the mass ratio of PBT melt-blown material and polydimethylsiloxane (PDMS) was 96:4.

[0146] The scanning electron microscope image of the polyester material prepared in Comparative Example 1 is shown in Figure 8 .

[0147] Comparative Example 2

[0148] The polyester material was prepared according to the method of Example 3, except that in step (2), no polydimethylsiloxane (PDMS) was added, and the mass ratio of PBT melt-blown material and silicon dioxide was 96:4.

[0149] The scanning electron microscope image of the polyester material prepared in Comparative Example 2 is shown in Figure 9 .

[0150] Comparative Example 3

[0151] (1) Three-dimensional crimped hollow PET fibers with fineness of 2.78 dtex, 6.67 dtex and 14.44 dtex respectively were mixed in a mass ratio of 10:60:30, and the mixed fibers were processed by a cotton feeder, a coarse opener, a fine opener and a carding machine to form a uniform cotton web, and then the cotton web was blown apart by a blowing machine;

[0152] (2) PBT melt-blown fibers were obtained by melt-blown spinning using PBT melt-blown material with intrinsic viscosity of 1.0 dl / g, melting point of 225℃ and melt index of 200 g / min, and the main melt-blown process was as follows: die temperature was 290℃, melt-blown receiving distance was 100 mm, and drawing hot air temperature was 310℃;

[0153] (3) The above three-dimensional crimped hollow PET mixed fibers were synchronously fed into the PBT melt-blown fibers which were not completely cooled, and the mass ratio of the three-dimensional crimped hollow PET mixed fibers to the PBT melt-blown fibers was 60:40, and the three-dimensional crimped hollow PET mixed fibers and the PBT melt-blown fibers were compounded by using thermal bonding, so as to prepare a polyester material; wherein the height difference between the outlet of the blowing machine and the melt-blown die was 50 mm.

[0154] The scanning electron microscope graph of the polyester material prepared in Comparative Example 3 is shown in Figure 10 .

[0155] Comparative Example 4

[0156] (1) Three-dimensional crimped hollow PET fibers with fineness of 2.78 dtex, 6.67 dtex and 14.44 dtex respectively were mixed in a mass ratio of 10:60:30, and the mixed fibers were processed by a cotton feeder, a coarse opener, a fine opener and a carding machine to form a uniform cotton web, and then the cotton web was blown apart by a blowing machine;

[0157] (2) PP melt-blown fibers were obtained by melt-blown spinning using polypropylene (PP) melt-blown material with intrinsic viscosity of 0.90 dl / g, melting point of 165℃ and melt index of 1500 g / min, and the main melt-blown process was as follows: die temperature was 230℃, melt-blown receiving distance was 150 mm, and drawing hot air temperature was 250℃;

[0158] (3) The above three-dimensional crimped hollow PET mixed fibers were synchronously fed into the PP melt-blown fibers which were not completely cooled, and the mass ratio of the three-dimensional crimped hollow PET mixed fibers to the PP melt-blown fibers was 60:40, and the three-dimensional crimped hollow PET mixed fibers and the PP melt-blown fibers were compounded by using thermal bonding, so as to prepare a polyester material; wherein the height difference between the outlet of the blowing machine and the melt-blown die was 50 mm.

[0159] Comparative Example 5

[0160] (1) mixing three-dimensional crimped hollow PET fibers with fineness of 2.78 dtex, 6.67 dtex and 14.44 dtex respectively according to a mass ratio of 10:60:30, forming a uniform cotton web after the mixed fibers are processed through a cotton feeder, a rough opener, a fine opener and a carding machine, and then blowing the cotton web apart through a blowing machine;

[0161] (2) using PET melt-blown material with a specific viscosity of 0.50 dl / g, a melting point of 180℃ and a melt index of 600 g / min to perform melt-blown spinning to obtain PET melt-blown fibers, the main melt-blown process: die temperature is 260℃, melt-blown receiving distance is 100mm, and hot air temperature is 280℃;

[0162] (3) synchronously feeding the above three-dimensional crimped hollow PET mixed fibers into the PET melt-blown fibers which have not yet completely cooled, the mass ratio of the three-dimensional crimped hollow PET mixed fibers to the PET melt-blown fibers is 60:40, and the three-dimensional crimped hollow PET mixed fibers and the PET melt-blown fibers are compounded by using thermal bonding, so as to prepare a polyester material; wherein the height difference between the outlet of the blowing machine and the melt-blown die is 50mm.

[0163] Test Example 1

[0164] The porosity, average sound absorption coefficient and heat resistance of the polyester materials prepared in Examples 1-14 and Comparative Examples 1-5 were tested, and the results are shown in Table 1.

[0165] Table 1

[0166]

[0167]

[0168] From the results in Table 1, compared with Comparative Examples 1-5, the polyester materials prepared by the preparation method provided in Examples 1-14 have good absorption of low-frequency sound waves and high-frequency sound waves, excellent sound absorption effect, and high thermal stability and good heat resistance at high temperatures.

[0169] Test Example 2

[0170] The diameter and crystallinity of the first polyester melt-blown fibers obtained in Examples 1-14 and Comparative Examples 1-5 were tested, and the grammage of the prepared polyester materials was tested, and the results are shown in Table 2.

[0171] Table 2

[0172]

[0173]

[0174] Test Example 3

[0175] The components of the polyester materials prepared in Examples 1 to 14 and Comparative Examples 1 to 5 were detected by differential scanning calorimeter (DSC) and infrared spectrometer. The polyester materials were ashed at high temperature to burn off the organic matter, and the remaining was silica. The results of the content of component a and silica in the polyester materials are shown in Table 3.

[0176] Table 3

[0177]

[0178]

[0179] The preferred embodiments of the present application are described in detail above, but the present application is not limited thereto. Within the technical concept of the present application, various simple modifications can be made to the technical solutions of the present application, including the combination of various technical features in any other suitable manner. These simple modifications and combinations should also be considered as disclosed by the present application and fall within the protection scope of the present application.

Claims

1. A polyester material, characterized by, The average sound absorption coefficient of the polyester material is 0.61-0.95 at a frequency less than 1000 Hz, 0.74-0.96 at a frequency of 1000-5000 Hz, and 0.64-0.96 at a frequency greater than 5000 Hz; and the size shrinkage of the polyester material is not higher than 3% at a temperature of 0-215 ℃. The polyester material contains a first polyester, a second polyester, a component a with a structural formula as shown in formula (I), and silicon dioxide; the first polyester is different from the second polyester, and each of the first polyester and the second polyester is independently selected from at least one of polybutylene terephthalate, polyethylene terephthalate, and polytrimethylene terephthalate; Formula (I); wherein R1, R2, R3, R4, R5, R6, R7, and R8 are each independently hydrogen or C1-C4 alkyl, and n is an integer of 6-500. In the polyester material, the content of the component a is 0.4-2.1% by weight, and the content of the silicon dioxide is 0.4-2.1% by weight; and the weight ratio of the first polyester, the component a, and the silicon dioxide is 18-98:1:0.3-3.

2. The polyester material according to claim 1, characterized in that, The porosity of the polyester material is 47-70%.

3. The polyester material according to claim 1, characterized in that, R1, R2, R3, R4, R5, R6, R7, and R8 are each independently hydrogen, methyl, and ethyl.

4. The polyester material according to claim 3, characterized in that, The average particle size of the silicon dioxide is 100-3000 nm.

5. The method for preparing the polyester material as described in claim 1, characterized in that, The method comprises the following steps: (1) mixing a first polyester, a component a with a structural formula as shown in formula (I), and silicon dioxide, and then performing melt-blowing spinning to obtain first polyester melt-blown fibers; the weight ratio of the first polyester, the component a, and the silicon dioxide is 18-98:1:0.3-3; Formula (I); wherein R1, R2, R3, R4, R5, R6, R7, and R8 are each independently hydrogen or C1-C4 alkyl, and n is an integer of 6-500. (2) pre-treating fibers containing a second polyester, and then compounding the fibers with the first polyester melt-blown fibers obtained in step (1); the first polyester is different from the second polyester, and the weight ratio of the fibers containing the second polyester and the first polyester melt-blown fibers is 0.4-2.5:

1.

6. The preparation method according to claim 5, characterized in that, R1, R2, R3, R4, R5, R6, R7, and R8 are each independently hydrogen, methyl, or ethyl. The average particle size of the silicon dioxide is 100-3000 nm.

7. The production method according to claim 5 or 6, characterized by, In step (1), the intrinsic viscosity of the first polyester is 0.50-1.00 dl / g, the melting point is 180-225 ℃, and the melt index at 190 ℃ under a load of 2.16 kg is 200-820 g / 10 min; The conditions of the melt-blowing spinning at least include: a melt-blowing die temperature of 240-290 ℃, a melt-blowing receiving distance of 70-180 mm, and a drawing hot air temperature of 260-290 ℃; The diameter of the first polyester melt-blown fibers is 2.0-3.0 μm, and the crystallinity is 40-50%.

8. The production method according to claim 5 or 6, characterized by, In step (2), the fibers containing the second polyester have a three-dimensional crimped hollow structure. The second polyester-containing fiber has a fineness of 1-15 dtex and a hollow rate of 20-35%.

9. The production method according to claim 8, characterized by, The second polyester-containing fiber contains at least one of a first fineness fiber, a second fineness fiber and a third fineness fiber; the first fineness fiber has a fineness greater than 1 dtex and less than or equal to 4 dtex, the second fineness fiber has a fineness greater than 4 dtex and less than 9 dtex, and the third fineness fiber has a fineness greater than or equal to 9 dtex and less than 15 dtex.

10. The method of claim 9, wherein, The second polyester-containing fiber contains at least one of a first fineness fiber, a second fineness fiber and a third fineness fiber; The weight ratio of the first fineness fiber, the second fineness fiber and the third fineness fiber is 1:1-6:1-6.

11. The method of claim 10, wherein, The pre-treatment process comprises: opening and carding the second polyester-containing fiber into a fiber web, and beating the fiber web; The compounding is performed by heat bonding; The heat bonding condition at least comprises: a temperature of 240-290 ℃ and a time of 5-60 s.

12. Use of the polyester material according to any one of claims 1 to 4 or prepared by the preparation method according to any one of claims 5 to 11 in the preparation of sound-absorbing articles.

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