CN116144207A

CN116144207A - Sound insulation coating with good absorption effect on low-frequency sound waves and preparation method thereof

Info

Publication number: CN116144207A
Application number: CN202211605509.XA
Authority: CN
Inventors: 王四九; 任强
Original assignee: Jiangsu Jiunuo New Material Technology Co ltd
Current assignee: Jiangsu Jiunuo New Material Technology Co ltd
Priority date: 2022-12-14
Filing date: 2022-12-14
Publication date: 2023-05-23
Anticipated expiration: 2042-12-14
Also published as: CN116144207B

Abstract

The invention provides a sound-insulating coating with good absorption effect on low-frequency sound waves and a preparation method thereof. The method aims at the problem that the traditional sound attenuation material has little effect in the aspect of suppressing low-frequency sound below 1000 Hz. According to the invention, MOFs material MIL53 (Fe) with stronger attenuation to low-frequency sound is screened out, and an in-situ solvothermal synthesis technology is adopted to load the MOFs material MIL53 (Fe) onto the surface of a specific inorganic fiber. The fiber is used for preparing the sound insulation coating, so that the high-efficiency absorption of the coating on low-frequency sounds such as low-frequency sounds of 1000Hz and below, human voice and the like is realized, and the noise reduction coefficient NRC of the coating with the thickness of 3mm can reach 0.80. Meanwhile, according to the GB/T8626-2007 test, the surface of the coating is subjected to flame burning for 30 seconds, is not ignited, is not dripped, is not ignited to filter paper below, and has excellent flame retardant property, so that A1-level flame retardance is achieved.

Description

Sound insulation coating with good absorption effect on low-frequency sound waves and preparation method thereof

Technical Field

The invention relates to a sound-insulating coating with good absorption effect on low-frequency sound waves and a preparation method thereof, and in particular relates to a sound-insulating coating prepared from inorganic fibers loaded with MOFs MIL53 (Fe). The coating of the present invention can provide excellent sound insulation effects after being sprayed on a ceiling or a wall surface of a building.

Background

The modern residence has the problem of poor sound insulation of the floor, and the noise generated on the floor directly influences the sleeping and daily life of the residents on the floor. The problem of how to create an acoustically comfortable space and how to provide people with a quiet and comfortable living environment is of increasing interest. The frequency range of sound which can be heard by human ears is generally 20Hz to 20000Hz, the wavelength of low-frequency sound is longer, the sound can be easily spread by bypassing the barrier, and the traditional sound attenuation material has little effect in inhibiting the low-frequency sound below 1000 Hz.

For example, the material for damping and sound insulation in China is mainly an acoustic board, and most common commercial acoustic boards are boards made of mineral wool. The mineral wool boards are adhered to a ceiling or a wall needing a sound insulation effect through a specific adhesive, gaps among the boards are filled, and finally the boards are integrally painted with a paint to form an integral decoration effect, so that the installation process is complex and is not easy to adapt to uneven special-shaped surface installation. In addition, the low frequency sound insulation effect of the thin mineral wool board is not ideal, and the sufficiently effective low frequency band absorption requires an increase in the board thickness to 50mm or more. As such, while meeting the acoustic comfort requirements, building space is sacrificed.

Based on the above problems, water-based soundproof paint for floor soundproof has been developed, and chinese patent CN201911276898.4 discloses a water-based soundproof paint for floor soundproof damping and a preparation method thereof. The sound-insulating paint coated on floor includes emulsion, stuffing, aggregate, halogen-free fire retardant, defoaming agent, bactericide, thickener, dispersant, deionized water, rubber grains and rubber fiber. However, the coating also uses the thickness of the coating itself and the overlapping between the aggregates to form millimeter and micron holes for absorbing sound, the sound absorbing effect on the low frequency part is poor, and the rubber particles and the fibers are still inflammable materials, so that fire hazards exist. Chinese patent CN 108384343B discloses a coating composition capable of absorbing sound and reducing noise, which comprises acrylic emulsion, film forming aid, surfactant, thickener, inorganic filler, and biochar particles made of cactus, sisal hemp, agave leaf, sarcandra leaf, corn stalk, ramie, flax, apocynum venetum, hemp, undaria pinnatifida, kelp, etc. The composition has a sound absorption coefficient of 0.47 to 0.59 for high frequency sound and has no listed effect for low frequency sound absorption.

MOFs are english abbreviations of metal-organic framework compounds, which generally refer to a class of organic-inorganic hybrid species constructed from metal ions/clusters and organic ligands through directed coordination bonds, whose properties blend with those of both inorganic and organic components. Metal organic framework compounds (MOFs) have attracted considerable attention over the past 20 years due to their diverse chemical, physical structures and properties. MOFs material has wide application prospect in gas storage separation, catalysis, pharmacy and other aspects. For example, patent CN202010114652.3 discloses a preparation method of an activated carbon fiber material loaded with Fe-MOF, which benefits from the high specific surface area and high porosity of the MOF material, and the activated carbon fiber material loaded with MOF has an excellent decolorizing effect on high-concentration organic dye in printing and dyeing wastewater. MOFs material has anisotropic, low-density, high-porosity, organic-inorganic alternate hybrid structure, and has great application potential in the aspect of sound absorption materials, but little research is performed. The absorption of low-frequency sounds such as bass sounds and human voices with frequencies of 1000Hz and below is not reported yet, and the application of the low-frequency sounds in sound-insulating paint is not reported.

The invention aims to overcome the defect that the sound-absorbing plate for ceilings and walls has poor attenuation effect on low-frequency sound waves, utilizes a specific MOFs material MIL53 (Fe) to load the surface of inorganic fibers through an in-situ solvothermal synthesis technology, and uses the fibers to prepare sound-insulating paint. The MIL53 (Fe) -loaded fiber is used for preparing sound insulation paint, and the absorption of low-frequency sounds such as bass sounds, human voice sounds and the like with the frequency of 1000Hz and below by the paint is realized. The coating on the surface of the wall (especially the ceiling) of the building provides excellent low-frequency sound insulation effect and can obviously improve the acoustic environment. Meanwhile, the inorganic mineral fiber-based coating has excellent flame retardant property, does not burn when meeting fire, and does not produce smoke. According to GB/T8626-2007 test, the surface of the coating is subjected to flame burning for 30 seconds, the coating is not ignited, low-falling matters are avoided, filter paper below the coating is not ignited, and the coating has excellent flame retardant property and achieves A1-level flame retardance.

Disclosure of Invention

The invention aims to overcome the defect that the traditional sound-insulating paint has weaker sound attenuation capability in the low-frequency sound wave band below 1000Hz, further improve the sound-insulating effect of the sound-insulating paint for ceilings and walls, and provide quiet and comfortable living environment for residents.

The technical scheme for realizing the aim of the invention is as follows: a sound-insulating paint with good absorption effect on low-frequency sound waves and a preparation method thereof are provided, wherein the sound-insulating paint comprises the following components:

inorganic fiber loaded with MOFs MIL53 (Fe) 10-20%

10 to 20 percent of inorganic water-based resin

1 to 3 percent of polymer emulsion

Pigment and filler 1-15%

0.1 to 3 percent of auxiliary agent

The balance being water

Further, the preparation method of the MOFs MIL53 (Fe) loaded inorganic fiber comprises the following steps:

(1) Preparing granular inorganic fibers or a mixture of a plurality of granular inorganic fibers in a certain mass ratio; preparing a mixed solution of citric acid and sodium dihydrogen phosphate for later use; preparing DMF (N, N-dimethylformamide) solution of ferric chloride and terephthalic acid for standby.

(2) The prepared inorganic fiber is added into a high-speed mixer, and is heated to the temperature of 50-60 ℃ while being stirred at the stirring speed of 50-100 r/min. Then adding a silane coupling agent accounting for 10-20% of the total mass of the inorganic fiber for activation reaction for 10-40 min, wherein the silane is one or more selected from epoxy silane KH-560 and amino silane KH-550.

(3) And (3) spraying and adding the prepared mixed solution of citric acid and sodium dihydrogen phosphate with the mass of 1:1 to the surface of the inorganic fiber activated in the step (2) through an atomization device under the condition of stirring at 50 ℃, stirring at a high speed for 200-500 r/min after the addition, and preserving the heat for 10-20 minutes.

(4) Raising the temperature of the high-speed mixer to 180-190 ℃ under stirring, and preserving the heat for 10-15 minutes to obtain the carboxylated inorganic fibers.

(5) Cooling to room temperature, stopping stirring, adding the prepared DMF (N, N-dimethylformamide) solution of ferric trichloride and terephthalic acid, adding a high-speed mixer to 130 ℃ at a speed of 5-10 ℃/min, and preserving the temperature for 6-8 hours.

(6) Filtering, taking out the fiber, washing with ethanol, and removing unreacted substances to obtain the inorganic fiber loaded with MIL53 (Fe).

Further, the concentration of citric acid in the mixed solution of citric acid and sodium dihydrogen phosphate is 1-1.2mol/L, and the concentration of sodium dihydrogen phosphate is 0.5-0.6mol/L; the dosage of the mixed solution of citric acid and sodium dihydrogen phosphate is 10-15 percent of the weight of the inorganic fiber.

Further, in DMF solution of ferric chloride and terephthalic acid, the concentration of ferric chloride in the solution is 0.15-0.2mol/L, and the concentration of terephthalic acid in the solution is 0.075-0.1mol/L; the ratio of the volume of the DMF (N, N-dimethylformamide) solution of the ferric chloride and the terephthalic acid to the weight of the inorganic fiber after carboxylation is 40L/kg-45L/kg.

Further, the inorganic fiber is in the form of a mixture of one or more of ceramic fiber, glass fiber and rock wool fiber. Ceramic fibers include, but are not limited to, alumina fibers, zirconia fibers, aluminum silicate fibers, titania fibers, silicon carbide fibers. Further preferred are alumina fibers.

Further, the inorganic water-based resin is organosilicon grafted modified potassium silicate with the modulus of 3.8-4.0.

Further, the pigment is rutile titanium dioxide, and the filler is one or more of boric acid, borax, glass beads and aluminum hydroxide; the auxiliary agent at least comprises a cellulose ether stabilizer, a polycarboxylate dispersant, a silicone defoamer and a silicone hydrophobizing agent.

The invention relates to a sound insulation coating with good absorption effect on low-frequency sound waves and a preparation method thereof, wherein MOFs (organic metal framework material) MIL53 (Fe) is loaded on the surface of an inorganic fiber prepared by the method, and the process of loading MIL53 (Fe) on the surface of the fiber involves chemical reaction. First, a part of hydroxyl groups on the surface of the fiber is subjected to dehydration condensation reaction with hydroxyl groups generated by hydrolysis of silane containing epoxy groups and amino groups, so that epoxy groups or amino groups are grafted, the epoxy groups or amino groups react with a part of carboxyl groups on citric acid, and the surface of the fiber is connected with carboxyl groups. The carboxyl groups on the fibers then coordinate with the metal ions in the solution. The metal ions grafted onto the fibers then undergo a coordination reaction with the organic ligands in solution. Finally, through the continuous self-assembly of metal ions and organic ligands on the fiber surface, an organometallic framework material, labeled MILs 53 (Fe), was successfully grown on the fiber surface.

The preparation method of the sound-insulating coating containing MIL53 (Fe) inorganic fiber comprises the following steps: adding metered water and an auxiliary agent into a dispersing kettle for pre-dispersing, adding inorganic water-based resin and polymer emulsion for uniform mixing, slowly adding inorganic fibers loaded with MOFs MIL53 (Fe), mixing for 30-60 minutes under the stirring of 200-500 rpm until the granular fibers are uniformly dispersed, adding pigment and filler with the formula amount, and mixing for 20-40 minutes under the stirring of 500-1000 rpm to obtain the sound insulation coating.

In the coating, the multilayer organic-inorganic alternate hybridization structure from micron level to nanometer level formed by the deposition of MIL-53 (Fe) on the surface of the inorganic fiber can greatly increase the flow resistance of air in the fiber, so that the viscous vibration of the air is generated to increase the dissipative acoustic energy, the sound absorption performance of the coating at low frequency is improved, and the overall sound insulation performance of the coating is improved.

After the technical scheme is adopted, the invention has the following positive effects:

(1) The sound-insulating coating consists of inorganic fibers loaded with a metal framework material MIL53 (Fe), water-based resin, pigment and filler and an auxiliary agent. MIL-53 (Fe) grows and deposits on the surface of the inorganic fiber, a multi-layer organic-inorganic alternate hybridization structure from micron level to nanometer level is formed, and the cooperation of the micron level and the nanometer level structure greatly increases the flow resistance of air in the fiber and enhances the dissipation of sound wave energy under different frequencies. The result shows that when the thickness of the coating is 3mm, compared with the traditional sound insulation material, the sound insulation material has good absorption effect on low-frequency sounds with the frequency of 1000Hz and below, so that the average noise reduction coefficient NRC of the coating can reach 0.80. Shows good sound insulation effect.

(2) The inorganic fibers adopted by the invention are flame-retardant, and after MIL-53 (Fe) is loaded, the flame-retardant property of the fibers is not affected, and the inorganic water-based resin is a non-combustible material. The prepared sound-insulating coating is applied to the indoor ceilings or walls of buildings and has excellent flame retardant property. According to GB/T8626-2007 test, the surface of the coating is subjected to flame burning for 30 seconds, the coating is not ignited, the continuous burning is 0, no low-drop matters exist, the lower filter paper is not ignited, the excellent flame retardant performance is achieved, and A1-level flame retardance can be achieved.

Drawings

The invention is further described below with reference to the accompanying drawings.

FIG. 1 is an X-ray diffraction (XRD) pattern of the alumina fiber, MIL-53 (Fe) and MIL-53 (Fe) -loaded alumina fiber in the coating of example 1.

FIG. 2 is an SEM image of MIL-53 (Fe) MOFs alumina fibers of example 1.

Detailed Description

For the purpose of making the objects, technical solutions and advantages of the embodiments of the present invention more apparent, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention, and it is apparent that the described embodiments are some embodiments of the present invention, but not all embodiments of the present invention.

The implementation conditions employed in the examples may be further adjusted according to specific requirements. The raw materials related to the modified fiber comprise citric acid, sodium dihydrogen phosphate, ferric chloride, terephthalic acid, DMF, a silane coupling agent, granular ceramic fiber, glass fiber and rock wool fiber which are all commercial industrial grade products, wherein the diameter of the granular fiber is less than or equal to 5 micrometers, and the length of the granular fiber is 2-6 millimeters. The raw materials used for the coating are also commercial products, and typical purchasing approaches are as follows: the modulus of the organosilicon coated grafted modified potassium silicate is 3.8-4.0, and the organosilicon coated grafted modified potassium silicate is purchased from Anhui porcelain and new material Co., ltd; the alkali-resistant acrylic emulsion is an emulsion of a trade mark Crosfect 508 of Australian wetting industry; the glass beads are HL30 hollow glass beads produced by Santa Clay; boric acid, borax and aluminum hydroxide are commercial materials with the particle size of more than 200 meshes; cellulose ether stabilizers, polycarboxylate dispersants, silicone defoamers and silicone hydrophobing agents are conventional commercially available materials.

The test method is as follows:

x-ray diffraction (XRD): the spectra of the inorganic fiber, MIL-53 (Fe) and MIL-53 (Fe) -loaded inorganic fiber were respectively tested by X-ray diffraction, and XRD spectra of 5-50℃were recorded.

Scanning Electron Microscope (SEM): and (3) observing by adopting a Japanese JSM-6510 scanning electron microscope, wherein the microscopic surface is sprayed with gold, and the accelerating voltage is 15kV.

Flame retardancy of the coating:

according to the GB/T8626-2007 test, in which the surface of the coating is subjected to flame ignition for 30 seconds, a filter paper is placed under the coating to be tested, particles formed by combustion are collected and whether the filter paper is ignited or not is observed.

Coating sound insulation:

the sound-insulating properties of a coating are measured by the sound absorption coefficient, which is the ratio of the sound energy absorbed by the coating itself to the sound energy incident on the surface of the material. The greater the sound absorption coefficient, the better the sound-insulating effect, the sound absorption coefficient (α) of the coating ₀ ) The test was performed according to GB/T18696.2-2002 using a SW002 standing wave tube, BSWA VS302USB dual-acoustic analyzer and a BSWA-100 power amplifier, manufactured by Beijing reputation sonophore technology Co. The noise reduction coefficient refers to the arithmetic average value of the sound absorption coefficient of the material at the center line frequency of 250Hz, 500Hz, 1000Hz and 2000Hz, two bits after the decimal point is calculated, and 0 or 5 is rounded off at the last bit.

Example 1: the embodiment provides a sound insulation coating with good absorption effect on low-frequency sound waves, which comprises, by mass, 10% of organosilicon grafted modified potassium silicate, 1.4% of alkali-resistant acrylic emulsion, 20% of alumina fiber loaded with MIL-53 (Fe), 1% of rutile titanium dioxide, 1.5% of borax, 1.5% of boric acid, 2% of glass beads, 3% of aluminum hydroxide, 0.6% of cellulose ether stabilizer, 0.5% of polycarboxylate dispersant, 0.3% of organosilicon defoamer, 0.2% of organosilicon hydrophobe and 58.0% of deionized water.

Wherein, the alumina fiber loaded with MIL-53 (Fe) is carried out according to the following steps:

(1) Preparing granular alumina fiber; preparing a mixed solution of citric acid and sodium dihydrogen phosphate for later use, wherein the concentration of the citric acid is 1mol/L, and the concentration of the sodium dihydrogen phosphate is 0.5mol/L; preparing DMF (N, N-dimethylformamide) solution of ferric chloride and terephthalic acid for later use, wherein the concentration of the ferric chloride DMF solution is 0.15mol/L; the concentration of the terephthalic acid DMF solution is 0.075mol/L.

(2) The prepared granular alumina fibers were added to a high speed mixer, and stirring and heating at a low speed of 50 rpm were started, and heating was performed to a fiber temperature of 50℃while stirring. Then adding an epoxy silane coupling agent KH560 accounting for 10 percent of the total mass of the fiber for activation reaction for 20 minutes to perform activation.

(3) And (3) spraying the prepared mixed solution of citric acid and sodium dihydrogen phosphate on the surface of the inorganic fiber after the activation in the step (2) through an atomization device under the condition of stirring at 50 ℃, wherein the mass ratio of the citric acid to the sodium dihydrogen phosphate is 10% of the weight of the inorganic fiber, stirring at a high speed for 200 r/min after adding, and preserving heat for 15 minutes.

(4) The temperature of the high-speed mixer is increased to 180 ℃ under stirring, and the temperature is kept for 13 minutes, so as to obtain carboxylated inorganic fibers.

(5) Cooling to room temperature, stopping stirring, adding prepared DMF (N, N-dimethylformamide) solution of ferric chloride and terephthalic acid, wherein the volume of the DMF (N, N-dimethylformamide) solution of ferric chloride and terephthalic acid and the volume-weight ratio of inorganic fibers after carboxylation treatment are 40L/kg, heating a high-speed mixer to 130 ℃ at the speed of 5 ℃/min, and preserving heat for 6 hours.

(6) Filtering, taking out the fiber, washing with ethanol, and removing unreacted substances to obtain the alumina fiber loaded with MIL53 (Fe).

XRD was used to characterize the structure of the alumina fiber, MIL-53 (Fe) and MIL-53 (Fe) -loaded alumina fiber, respectively, in example 1. As shown in FIG. 1, MIL53 (Fe) has obvious diffraction peaks at 9.4 degrees, 12.4 degrees, 17.6 degrees and 25.45 degrees, and the peak positions are consistent with the literature reports, which shows that the prepared MIL-53 (Fe) is a crystal with high crystallinity. The characteristic peaks of the alumina fiber are 33.0 °, 37.8 ° and 39.4 ° and 45.5 °, respectively. By analyzing the main diffraction peak positions of the alumina fiber loaded with MIL-53 (Fe), it can be seen that diffraction peaks of the alumina fiber and MIL-53 (Fe) appear simultaneously in the XRD pattern of the alumina fiber loaded with MIL-53 (Fe), but the peaks corresponding to the alumina fiber are very weak, which means that the fiber surface is covered by a layer of MIL53 (Fe).

FIG. 2 shows SEM images of alumina fibers supporting MIL53 (Fe) MOFs, showing dense growth of MIL53 (F2) MOFs with crystal grain sizes of about 500nm on the surface of alumina fibers with diameters of about 2 microns. Inside the MOF there are also holes on the nano-scale that are not observed. The multi-layer micro-hole and nano-hole structure can effectively attenuate sound waves with different frequency bands, including sound waves with the frequency below 1000 Hz.

The preparation method of the sound-insulating paint comprises the following steps: adding 58% of water, 0.6% of cellulose ether stabilizer, 0.5% of polycarboxylate dispersant, 0.3% of organosilicon defoamer and 0.2% of organosilicon hydrophobing agent into a dispersing kettle for pre-dispersing, adding 10% of organosilicon grafted modified potassium silicate and 1.4% of alkali-resistant acrylic emulsion, uniformly mixing, slowly adding 20% of alumina fiber loaded with MIL53 (Fe) and stirring for 60 minutes at 200 rpm until the granular fiber is uniformly dispersed, and then adding 1% of rutile titanium pigment, 1.5% of borax, 1.5% of boric acid, 2% of glass beads and 3% of aluminum hydroxide according to the total mass of the formula, and stirring for 30 minutes at 500 rpm to obtain the sound-insulating coating. And (3) spraying the paint onto a cement substrate by adopting a CY9511A type building paint spray gun twice, wherein a spraying gap is 48 hours, and finally forming a paint film with the thickness of 3mm, drying for 7 days, and testing the performance.

The flame retardant properties of the coatings prepared in example 1 are shown in Table 1 below.

Table 1 shows the flammability performance of the coating (3 mm) of example 1, six panels were prepared, three for the surface ignition mode and three for the edge ignition mode.

TABLE 1 flammability Performance test of example 1 coating

As can be seen from Table 1, the panel was completely free from fire and had a continuous burning time of 0s, and the soundproof coating achieved A1-grade fireproof performance

The sound absorption coefficients of the coatings prepared in example 1 at different frequencies are shown in table 2 below.

TABLE 2 Sound absorption coefficient of coating (3 mm) of example 1

Example 1 the noise reduction coefficient of example 1 was calculated from the data in the table to be 0.80 as a result of the sound absorption coefficient test according to GB/T18696.2-2002 when the coating layer was 3 mm. Example 1 is a preferred example.

Example 2: the difference from example 1 is that the alumina fiber is changed to a glass fiber. The test results are: the flame retardant property of the coating with the thickness of 3mm according to the test of GB/T8626-2007 is that the surface is subjected to flame burning for 30 seconds, the surface is not ignited, the continuous burning time is 0s, no low-falling matters exist, the filter paper below the surface is not ignited, and the fireproof property reaches A1 level; the noise reduction coefficient according to GB/T18696.2-2002 was 0.75 at 3mm of coating.

Example 3: the difference from example 1 is that the alumina fibers are changed to aluminum silicate fibers. The test results are: the flame retardant property of the coating with the thickness of 3mm according to the test of GB/T8626-2007 is that the surface is subjected to flame burning for 30 seconds, the surface is not ignited, low falling matters are not generated, filter paper below the surface is not ignited, and the grade A1 is achieved; the noise reduction coefficient according to GB/T18696.2-2002 was 0.70 at 3mm of coating.

Example 4: the difference from example 1 is that the alumina fiber is changed to the silicon carbide fiber. The test results are: the flame retardant property of the coating with the thickness of 3mm according to the test of GB/T8626-2007 is that the surface is subjected to flame burning for 30 seconds, the surface is not ignited, low falling matters are not generated, filter paper below the surface is not ignited, and the grade A1 is achieved; the noise reduction coefficient according to GB/T18696.2-2002 was 0.65 at 3mm of coating.

Example 5: unlike example 1, the paint formulation consisted of 13.0% silicone coated graft modified potassium silicate, 2.5% alkali resistant acrylic emulsion, 12.5% MILs-53 (Fe) loaded rock wool fiber, 2.5% rutile titanium dioxide, 1.0% borax, 1.0% boric acid, 4.5% glass beads, 6% aluminum hydroxide, 0.5% cellulose ether stabilizer, 0.5% polycarboxylate dispersant, 0.3% silicone defoamer, 0.2% silicone hydrophobe and 55.5% deionized water.

The test results are: the flame retardant property of the coating with the thickness of 3mm according to the test of GB/T8626-2007 is that the surface is subjected to flame burning for 30 seconds, the surface is not ignited, low falling matters are not generated, filter paper below the surface is not ignited, and the grade A1 is achieved; the noise reduction coefficient according to GB/T18696.2-2002 was 0.60 at 3mm of coating.

Example 6: unlike example 1, the paint formulation consisted of 15.0% silicone coated graft modified potassium silicate, 2.5% alkali resistant acrylic emulsion, 16.5% MILs-53 (Fe) -loaded zirconia fiber, 2.5% rutile titanium dioxide, 2.0% borax, 2.0% boric acid, 3.5% glass beads, 4% aluminum hydroxide, 0.5% cellulose ether stabilizer, 0.6% polycarboxylate dispersant, 0.3% silicone defoamer, 0.2% silicone hydrophobe and 50.4% deionized water.

The test results are: the flame retardant property of the coating with the thickness of 3mm according to the test of GB/T8626-2007 is that the surface is subjected to flame burning for 30 seconds, the surface is not ignited, low falling matters are not generated, filter paper below the surface is not ignited, and the grade A1 is achieved; the noise reduction coefficient according to GB/T18696.2-2002 was 0.75 at 3mm of coating.

Example 7: unlike example 1, the paint formulation consisted of 10.0% silicone coated graft modified potassium silicate, 1.5% alkali resistant acrylic emulsion, 15.0% MILs-53 (Fe) -loaded alumina fiber, 1.5% rutile titanium dioxide, 1.0% borax, 1.0% boric acid, 1.5% glass beads, 4% aluminum hydroxide, 0.6% cellulose ether stabilizer, 0.5% polycarboxylate dispersant, 0.3% silicone defoamer, 0.2% silicone hydrophobe and 62.9% deionized water.

The test results are: the flame retardant property of the coating with the thickness of 3mm according to the test of GB/T8626-2007 is that the surface is subjected to flame burning for 30 seconds, the surface is not ignited, low falling matters are not generated, filter paper below the surface is not ignited, and the grade A1 is achieved; the noise reduction coefficient according to GB/T18696.2-2002 was 0.65 at 3mm of coating. When the MIL-53 (Fe) -loaded alumina fiber was reduced from 20% to 15% in example 1, the noise reduction coefficient was reduced.

Comparative example 1 the difference from example 1 is that the alumina fiber loaded with the organometallic oxide MILs 53 (Fe) was changed to a pure alumina fiber without any loading.

Test results: the flame retardance of the coating is not obviously different from that of the coating in the embodiment 1, and the A1-grade fireproof performance is also achieved. The results of the sound absorption coefficient of the coating prepared in comparative example 1 at a thickness of 3mm are shown in table 3 below, and the sound absorption coefficient of the coating at 1000Hz or less is significantly reduced compared with example 1 (table 2), and the sound absorption coefficient of 1000Hz or more is not greatly changed, but the overall noise reduction coefficient is reduced by 0.20 and 0.60 compared with example 1. This is consistent with MILs 53 (Fe) primarily improving the sound absorption effect in the acoustic wave bands below 1000 Hz.

TABLE 3 Sound absorption coefficient of coating of comparative example 1 (3 mm)

Comparative example 2 unlike example 1, the alumina fiber loaded with the organometallic oxide MILs 53 (Fe) was replaced by a separately synthesized MILs 53 (Fe) powder in equal amounts, i.e., only MILs 53 (Fe) powder was used as a sound absorbing material.

The test results are shown in Table 4, the flame retardance of the coating is reduced relative to that of example 1, the coating can be ignited, but the continuous burning time is less than 20 seconds, the A2-grade fireproof requirement can be met, the A1-grade fireproof requirement cannot be met, and the flame retardance of the system is reduced due to the fact that only MIL53 (Fe) is adopted, which is equivalent to the fact that more organic components are introduced. The sound absorption coefficient is shown in table 5, and the sound insulation effect is remarkably reduced from 0.80 to 0.55 with respect to example 1. The sound absorption coefficient below 1000Hz is still higher as compared to comparative example 1, but the sound absorption coefficient above 1000Hz is significantly reduced. This is because the use of only MOF MIL53 (Fe) powder in place of the alumina fibers loaded with the metal oxide MIL53 (Fe) results in too few micro-scale voids and also reduces the sound-insulating effect on high frequency sound waves. To achieve full band noise reduction from low to high frequencies, it is necessary to use inorganic fibers, particularly alumina fibers, loaded with the organometallic oxide MILs 53 (Fe).

Table 4 flammability test of the coating of comparative example 2

TABLE 5 Sound absorption coefficient of coating of comparative example 2 (3 mm)

While the foregoing is directed to embodiments of the present invention, other and further details of the invention may be had by the present invention, it should be understood that the foregoing description is merely illustrative of the present invention and that no limitations are intended to the scope of the invention, except insofar as modifications, equivalents, improvements or modifications are within the spirit and principles of the invention.

Claims

1. The sound-insulating coating with good absorption effect on low-frequency sound waves is characterized by comprising the following raw materials in percentage by mass:

10 to 20 percent of inorganic fiber loaded with MIL53 (Fe)

10 to 20 percent of inorganic water-based resin

1-3% of polymer emulsion

Pigment and filler 1-15%

0.1 to 3 percent of auxiliary agent

The balance being water.

2. The soundproof coating material having excellent absorbing effect on low-frequency sound waves according to claim 1, wherein: the preparation method of the inorganic fiber loaded with MIL53 (Fe) comprises the following steps:

(1) Adding inorganic fibers into a high-speed mixer, heating to the temperature of 50-60 ℃ under the condition of low stirring speed of 50-100 r/min, and then adding a silane coupling agent accounting for 10-20% of the total mass of the inorganic fibers for activation reaction for 10-40 min, wherein the silane coupling agent is selected from one of epoxy silane KH-560 and amino silane KH-550;

(2) Spraying and adding the prepared mixed solution of citric acid and sodium dihydrogen phosphate to the surface of the activated inorganic fiber through an atomization device under the condition of stirring at 50 ℃, stirring at a high speed of 200-500 r/min after adding, and preserving the heat for 10-20 min;

(3) Raising the temperature of the high-speed mixer to 180-190 ℃ under stirring, and preserving the heat for 10-15 minutes to obtain carboxylated inorganic fibers;

(4) Cooling to room temperature, stopping stirring, adding DMF solution containing ferric chloride and terephthalic acid, heating a high-speed mixer to 130-140 ℃ at 5-10 ℃/min, and preserving heat for 6-8 hours;

(5) The fiber was taken out and filtered, and washed with ethanol to remove unreacted materials, thereby obtaining MILs 53 (Fe) -loaded inorganic fibers.

3. The soundproof coating material having excellent absorbing effect on low-frequency sound waves according to claim 1, wherein: the concentration of citric acid in the mixed solution is 1-1.2mol/L, and the concentration of sodium dihydrogen phosphate is 0.5-0.6mol/L; the mass ratio of the citric acid to the sodium dihydrogen phosphate is 1:1, and the dosage of the mixed solution is 10-15% of the mass of the inorganic fiber; the concentration of ferric chloride in DMF solution containing ferric chloride and terephthalic acid is 0.15-0.2mol/L, and the concentration of terephthalic acid is 0.075-0.1mol/L; the ratio of the volume of the DMF solution containing ferric chloride and terephthalic acid to the weight of the inorganic fiber after carboxylation is 40L/kg-45L/kg.

4. The soundproof coating material having excellent absorbing effect on low frequency sound waves according to claim 2, wherein: the inorganic fiber is one or a mixture of a plurality of ceramic fiber, glass fiber and rock wool fiber; wherein the ceramic fibers include, but are not limited to, one or more of alumina fibers, zirconia fibers, aluminum silicate fibers, silicon carbide fibers.

5. The soundproof coating material having excellent absorbing effect on low-frequency sound waves according to claim 1, wherein: the inorganic water-based resin is organic silicon grafted modified potassium silicate with the modulus of 3.8-4.0.

6. The soundproof coating material having excellent absorbing effect on low-frequency sound waves according to claim 1, wherein: the pigment is rutile type titanium dioxide; the filler is one or more of boric acid, borax, glass beads and aluminum hydroxide; the auxiliary agent at least comprises a cellulose ether stabilizer, a polycarboxylate dispersant, a silicone defoamer and a silicone hydrophobizing agent.

7. The method for producing a sound-insulating coating having a good absorption effect for low-frequency sound waves according to any one of claims 1 to 6: adding metered water and an auxiliary agent into a dispersing kettle for pre-dispersing, adding inorganic water-based resin and polymer emulsion for uniform mixing, slowly adding inorganic fibers loaded with MOFs MIL53 (Fe), mixing for 30-60 minutes under the stirring of 200-500 rpm until the granular fibers are uniformly dispersed, adding pigment and filler with the formula amount, and mixing for 20-40 minutes under the stirring of 500-1000 rpm to obtain the sound insulation coating.

8. The soundproofing paint having a good absorbing effect on low frequency sound waves according to any one of claims 1 to 6, wherein: the sound-insulating coating is used for having high absorptivity for low-frequency sounds with the frequency of 1000Hz and below, so that the overall noise reduction coefficient of the coating reaches 0.8.