Porous material, preparation method of porous material, noise reduction coating, noise reduction coating and application of noise reduction coating

Abstract

The invention provides a porous material and a preparation method thereof, a noise reduction coating, a noise reduction coating and application thereof, and the preparation method comprises the following steps: mixing a polyether type waterborne polyurethane dispersion and a silicon source, carrying out a hydrothermal reaction, and calcining the obtained hydrothermal reaction product to obtain the porous material. The polyether type waterborne polyurethane dispersion is used as a pore-foaming agent, the internal pore diameter of the obtained porous material is complex, a stronger effect is provided for repeated refraction and reflection energy consumption of sound, and the noise reduction effect is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of noise reduction materials, and in particular to a porous material and a preparation method thereof, a noise reduction paint, a noise reduction coating and applications thereof. Background Art

[0002] Automobile noise mainly comes from road noise, tire noise, wind noise and engine noise. Currently, automobiles have very high requirements for noise control.

[0003] In the prior art, the noise reduction in the car compartment is mainly achieved by improving the sealing of the compartment, the shock absorption system of the chassis, the sound insulation effect of the engine compartment, and the selection of silent tires, etc. However, the noise reduction effect is still limited, so it is necessary to develop new noise reduction materials for automobiles to improve the noise reduction effect of automobiles. Summary of the invention

[0004] In view of the shortcomings of the prior art, the purpose of the present invention is to provide a porous material and a preparation method thereof, a noise reduction coating, a noise reduction coating and its application. By combining a polyether type waterborne polyurethane dispersion and a silicon source, using the polyether type waterborne polyurethane dispersion as a porogen and using the silicon source to prepare silica, a silica porous material with suitable particle size and pore size is formed. This porous material can provide holes for repeated refraction and reflection of noise, thereby achieving excellent noise reduction effect.

[0005] To achieve this object, the present invention adopts the following technical solutions:

[0006] In a first aspect, the present invention provides a method for preparing a porous material, the preparation method comprising: mixing a polyether type aqueous polyurethane dispersion and a silicon source, and subjecting the mixture to a hydrothermal reaction, and calcining the obtained hydrothermal reaction product to obtain the porous material.

[0007] The present invention provides a different noise reduction functional filler, and its noise reduction principle lies in that the noise reduction filler prepared to produce the noise reduction effect is a multi-complex porous material. When the sound passes through the coating, it enters the pores of the porous material and the noise is consumed during repeated refraction in the pores.

[0008] In order to realize the above principle, a material with suitable pore size and suitable holes is required. In order to make the pore size length complex and diversified, the present invention adopts the preparation of polyether-type water-based polyurethane dispersion as a porogenic material. The polyether-type polyurethane water-based dispersion has a strong microphase separation structure and is in a curled-up agglomeration form. The polyether-type polyurethane water-based dispersion is mixed with a silicon source, and then a hydrothermal reaction is performed to make the silicon source form silicon dioxide on the surface of the polyether-type polyurethane water-based dispersion. The polyether-type polyurethane water-based dispersion is then removed through a calcination process, thereby obtaining a porous material with complex holes. The prepared internal pore size is complex, which provides a basis for the repeated refraction and reflection energy consumption of sound; and the polyether-type structure is adopted. Since the ether bond has a strong hydrogen bond, the agglomeration is more compact, and there are more channels in the silicon dioxide structure, which further increases the sound consumption efficiency.

[0009] Preferably, the molecular weight M of the polyether type waterborne polyurethane in the polyether type waterborne polyurethane dispersion is n The value is 60000 to 120000, for example, 60000, 66600, 73300, 80000, 86600, 93300, 100000, 106600, 113300 or 120000, but is not limited to the values ​​listed, and other values ​​not listed within the range are also applicable.

[0010] The present invention further prefers that the molecular weight M of the polyether type aqueous polyurethane dispersion n It is 60,000 to 120,000, has a higher molecular segment, and is in a curled-up agglomeration form. The prepared internal pore size is more complex, providing a stronger effect on the energy consumption of repeated refraction and reflection of sound.

[0011] Preferably, the polyether type aqueous polyurethane dispersion is in a curled and agglomerated form.

[0012] It is shown that the curled and agglomerated morphology is critical for forming holes that can repeatedly refract and reflect. It is precisely because the polyether-based waterborne polyurethane dispersion is in a curled and agglomerated morphology and the holes formed inside are not a simple single pore structure that it can have better sound consumption efficiency and further improve the noise reduction effect.

[0013] Preferably, the silicon source comprises any one of tetraethyl orthosilicate, white carbon or silica sol, or a combination of at least two of them, wherein typical but non-limiting combinations are a combination of tetraethyl orthosilicate and white carbon, a combination of silica sol and white carbon, and a combination of tetraethyl orthosilicate and silica sol.

[0014] Preferably, the molar ratio of the polyether waterborne polyurethane and the silicon source in the polyether waterborne polyurethane dispersion is (0.2-0.5):1, for example, it can be 0.2:1, 0.24:1, 0.27:1, 0.3:1, 0.34:1, 0.37:1, 0.4:1, 0.44:1, 0.47:1 or 0.5:1, etc., but is not limited to the listed values, and other unlisted values ​​within the range are also applicable.

[0015] In the present invention, the molar ratio of the polyether type waterborne polyurethane to the silicon source in the polyether type waterborne polyurethane dispersion is preferably controlled within the above range to obtain a porous material with moderate pore size and particle size.

[0016] Preferably, a first solvent is added during the mixing.

[0017] Preferably, the first solvent comprises water and ethanol.

[0018] Preferably, the molar ratio of water to ethanol in the first solvent is (15-100):(1-4), wherein the proportion of water can be, for example, 15, 16, 18, 20, 25, 30, 40, 50, 60, 70, 80, 90, 100, etc.; the proportion of ethanol can be, for example, 1, 2, 3 or 4, etc.

[0019] Preferably, the molar ratio of the first solvent to the silicon source is (16-104):1, for example, it can be 16:1, 26:1, 36:1, 46:1, 56:1, 65:1, 75:1, 85:1, 95:1 or 104:1, but is not limited to the listed values, and other unlisted values ​​within the range are also applicable.

[0020] Preferably, the raw materials for preparing the polyether type waterborne polyurethane in the polyether type waterborne polyurethane dispersion include: diisocyanate, polyether polyol, catalyst and chain extender.

[0021] Preferably, the chain extender accounts for 3-5wt% of the total mass of the raw materials, for example, it can be 3wt%, 3.3wt%, 3.5wt%, 3.7wt%, 3.9wt%, 4.2wt%, 4.4wt%, 4.6wt%, 4.8wt% or 5wt%, etc., but is not limited to the listed values, and other values ​​not listed within this range are also applicable.

[0022] Preferably, the chain extender comprises 2,2-dimethylolpropionic acid (DMPA) and / or 2,2-dimethylolbutanoic acid (DMBA).

[0023] Preferably, the molar ratio of the diisocyanate to the polyether polyol is 2:1 to 4:3, for example, 2:1, 1.8:1, 1.7:1, 1.6:1, 1.5:1, 1.4:1 or 4:3, but is not limited to the listed values, and other unlisted values ​​within the range are also applicable.

[0024] The present invention preferably controls the molar ratio of diisocyanate to polyether polyol within the above range, so as to obtain a polymer having a curled agglomerate morphology and a molecular weight M n In the dispersion of 6~12W.

[0025] Preferably, the catalyst accounts for 0.05-0.1wt% of the total mass of the raw materials, for example, it can be 0.05wt%, 0.06wt%, 0.07wt%, 0.08wt%, 0.09wt% or 0.1wt%, etc., but is not limited to the listed values, and other unlisted values ​​within this range are also applicable.

[0026] Preferably, the catalyst comprises an organotin catalyst.

[0027] Preferably, the diisocyanate comprises any one of isophorone diisocyanate, dicyclohexylmethane-4,4'-diisocyanate or hexamethylene diisocyanate, or a combination of at least two thereof, wherein typical but non-limiting combinations are a combination of isophorone diisocyanate and dicyclohexylmethane-4,4'-diisocyanate, a combination of hexamethylene diisocyanate and dicyclohexylmethane-4,4'-diisocyanate, and a combination of isophorone diisocyanate and hexamethylene diisocyanate.

[0028] Preferably, the number average molecular weight of the polyether polyol is 2000-3000, for example, 2000, 2110, 2220, 2330, 2445, 2550, 2660, 2770, 2880 or 3000, but is not limited to the listed values, and other unlisted values ​​within the range are also applicable.

[0029] Preferably, the polyether polyol comprises a combination of at least two of polytrimethylene ether glycol (PO3G), polytetramethylene glycol ether (PTMEG), polyethylene glycol (PEG) or polypropylene glycol (PPG), wherein a typical but non-limiting combination is a combination of polytrimethylene ether glycol and polytetramethylene glycol ether, a combination of polyethylene glycol and polytetramethylene glycol ether, a combination of polytrimethylene ether glycol and polyethylene glycol, a combination of polypropylene glycol and polytetramethylene glycol ether, preferably polytrimethylene ether glycol and polytetramethylene glycol ether.

[0030] Preferably, the preparation of the polyether type waterborne polyurethane dispersion comprises: mixing the raw materials and the second solvent, carrying out a chain extension reaction, adding a third solvent and a capping agent, and sequentially adjusting the pH by a first step, removing the solvent, and adjusting the pH by a second step to obtain the polyether type waterborne polyurethane dispersion.

[0031] Preferably, the second solvent comprises a ketone solvent.

[0032] Preferably, the ketone solvent includes acetone and / or butanone.

[0033] Preferably, the amount of the second solvent added is 1.5 to 2 times the total mass of the raw materials, for example, it can be 1.5 times, 1.6 times, 1.7 times, 1.8 times, 1.9 times or 2 times, but is not limited to the listed values, and other unlisted values ​​within this range are also applicable.

[0034] Preferably, the duration of the chain extension reaction is 1 to 4 hours, for example, it can be 1 hour, 1.4 hours, 1.7 hours, 2 hours, 2.4 hours, 2.7 hours, 3 hours, 3.4 hours, 3.7 hours or 4 hours, but is not limited to the listed values, and other values ​​not listed in this range are also applicable.

[0035] Preferably, the temperature of the chain extension reaction is 50-80°C, for example, 50°C, 55°C, 60°C, 65°C, 70°C, 75°C or 80°C.

[0036] Preferably, the amount of the third solvent added is 1.2 to 1.5 times the mass of the second solvent, for example, it can be 1.2 times, 1.24 times, 1.27 times, 1.3 times, 1.34 times, 1.37 times, 1.4 times, 1.44 times, 1.47 times or 1.5 times, etc., but is not limited to the listed values, and other unlisted values ​​within this range are also applicable.

[0037] Preferably, the end-capping agent comprises ethylenediamine and / or hexamethylenediamine.

[0038] Preferably, the adjusting agents used for the first pH adjustment and the second pH adjustment each independently include AMP95 and / or triethylamine.

[0039] Preferably, the first pH adjustment and the second pH adjustment independently adjust the pH to 7-9, for example, 7, 7.3, 7.5, 7.7, 7.9, 8.2, 8.4, 8.6, 8.8 or 9, but are not limited to the listed values, and other unlisted values ​​within the range are also applicable.

[0040] Preferably, the temperature of the hydrothermal reaction is 140-170°C, for example, it can be 140°C, 144°C, 147°C, 150°C, 154°C, 157°C, 160°C, 164°C, 167°C or 170°C, but is not limited to the listed values, and other unlisted values ​​within the range are also applicable.

[0041] Preferably, the hydrothermal reaction time is 72 to 96 h, for example, 72 h, 75 h, 78 h, 80 h, 83 h, 86 h, 88 h, 91 h, 94 h or 96 h, but is not limited to the listed values, and other unlisted values ​​within the range are also applicable.

[0042] Preferably, before the hydrothermal reaction, the preparation method further comprises: stirring the material for a certain period of time.

[0043] Preferably, the stirring temperature is room temperature.

[0044] Preferably, the stirring time is 10 to 15 hours, for example, it can be 10 hours, 10.6 hours, 11.2 hours, 11.7 hours, 12.3 hours, 12.8 hours, 13.4 hours, 13.9 hours, 14.5 hours or 15 hours, but is not limited to the listed values, and other unlisted values ​​within the range are also applicable.

[0045] Preferably, the calcination temperature is 600-700°C, for example, it can be 600°C, 612°C, 623°C, 634°C, 645°C, 656°C, 667°C, 678°C, 689°C or 700°C, but is not limited to the listed values, and other unlisted values ​​within the range are also applicable.

[0046] Preferably, the calcination time is 8 to 16 hours, for example, 8 hours, 8.9 hours, 9.8 hours, 10.7 hours, 11.6 hours, 12.5 hours, 13.4 hours, 14.3 hours, 15.2 hours or 16 hours, but is not limited to the listed values, and other values ​​not listed within the range are also applicable.

[0047] In a second aspect, the present invention provides a porous material, wherein the porous material is prepared by the method for preparing the porous material described in the first aspect.

[0048] The porous material provided in the second aspect of the present invention can better absorb sound due to the complex pore diameters inside.

[0049] Preferably, the porous material is a silica filler having pores, and the pores have a pore diameter of 55 to 100 nm, for example, 55 nm, 56 nm, 62 nm, 67 nm, 73 nm, 78 nm, 84 nm, 89 nm, 95 nm or 100 nm, etc., but is not limited to the listed values, and other unlisted values ​​within the range are also applicable.

[0050] The aperture in the present invention is adjusted through multiple tests and controlled at 55-100nm to achieve the best noise reduction effect. When the aperture is too large, the number of reflections will be greatly reduced, and the noise reduction effect of the sound will be poor. If it is too low, it will increase the difficulty of noise entering the aperture. After a lot of research, the optimal particle size range and particle size have been found.

[0051] It is worth mentioning that the core of the porous material of the present invention, in addition to the pore size, lies in the fact that the formed pores are not a single pore structure but a complex and repeated pore channel structure, which is different from the conventional pore structure. Such an effect is achieved through experimental research and the preparation method described in the first aspect of the present invention.

[0052] Preferably, the particle size D50 of the silica filler is 5 to 9 μm, for example, it can be 5 μm, 5.4 μm, 5.7 μm, 6 μm, 6.4 μm, 6.7 μm, 7 μm, 7.4 μm, 7.7 μm, 8 μm, 8.2 μm, 8.5 μm, 8.8 μm or 9.0 μm, but is not limited to the listed values, and other unlisted values ​​within the range are also applicable.

[0053] The present invention preferably controls the particle size of the silica filler within the above range, which is more conducive to the subsequent preparation of the coating, ensures the adhesion and other properties of the subsequent coating, and at the same time has a better noise reduction effect.

[0054] In a third aspect, the present invention provides a noise reduction coating, wherein the noise reduction coating comprises the porous material described in the second aspect.

[0055] Preferably, the noise reduction coating further comprises: a polyurethane dispersion and additives.

[0056] Preferably, the mass ratio of the porous material to the polyurethane dispersion in the noise reduction coating is (12-15):100, for example, it can be 12:100, 12.4:100, 12.7:100, 13:100, 13.4:100, 13.7:100, 14:100, 14.4:100, 14.7:100 or 15:100, but is not limited to the listed values, and other unlisted values ​​within the range are also applicable.

[0057] The present invention preferably controls the mass ratio of the porous material to the polyurethane dispersion within the above range, which has a better noise reduction effect.

[0058] Preferably, the polyurethane dispersion is an aqueous polyurethane dispersion.

[0059] Preferably, the polyurethane dispersion comprises any one of the commercially available waterborne polyurethane dispersions Haoyi New Material HYR-2435B, Haoyi New Material HYR-2125 or Covestro 2611, or a combination of at least two thereof, wherein a typical but non-limiting combination is a combination of Haoyi New Material HYR-2435B and Haoyi New Material HYR-2125, or a combination of Haoyi New Material HYR-2125 and / or Covestro 2611.

[0060] Preferably, the additives include a wetting agent, a defoaming agent, a leveling agent and a film-forming aid.

[0061] Preferably, the mass ratio of the additive to the polyurethane dispersion is (3.3-8.9):100, for example, it can be 3.3:100, 4:100, 4.6:100, 5.2:100, 5.8:100, 6.5:100, 7.1:100, 7.7:100, 8.3:100 or 8.9:100, but is not limited to the listed values, and other unlisted values ​​within the range are also applicable.

[0062] Preferably, the mass ratio of the wetting agent, defoaming agent, leveling agent, film-forming aid and polyurethane dispersion is (0.1-0.3):(0.1-0.3):(0.1-0.3):(3-8):100, wherein the proportion of the wetting agent can be, for example, 0.1, 0.13, 0.15, 0.17, 0.19, 0.22, 0.24, 0.26, 0.28 or 0.3, etc.; the proportion of the defoaming agent can be, for example, The proportion of the leveling agent may be, for example, 0.1, 0.13, 0.15, 0.17, 0.19, 0.22, 0.24, 0.26, 0.28 or 0.3, etc. The proportion of the film-forming aid may be, for example, 3, 3.5, 4, 5, 6, 7, 7.5 or 8, etc.

[0063] The present invention has no special requirements for the specific selection of the wetting agent, defoaming agent, leveling agent and film-forming aid. The materials that can be used for the wetting agent, defoaming agent, leveling agent and film-forming aid that are well known to those skilled in the art can be used, and can also be adjusted according to actual conditions.

[0064] Preferably, the wetting agent comprises Tego270 and / or BYK346.

[0065] Preferably, the defoaming agent comprises Tego902W and / or BYK093.

[0066] Preferably, the leveling agent includes Tego450 and / or BYK381.

[0067] Preferably, the film-forming aid includes any one of propylene glycol methyl ether, propylene glycol methyl ether acetate, alcohol ester dodeca or dipropylene glycol butyl ether acetate, or a combination of at least two of them, wherein a typical but non-limiting combination is a combination of propylene glycol methyl ether and propylene glycol methyl ether acetate, a combination of alcohol ester dodeca and propylene glycol methyl ether acetate, a combination of propylene glycol methyl ether and alcohol ester dodeca, and a combination of dipropylene glycol butyl ether acetate and alcohol ester dodeca.

[0068] In a fourth aspect, the present invention provides a noise reduction coating, wherein the noise reduction coating is formed by coating the noise reduction coating described in the third aspect.

[0069] Compared with the current mainstream noise reduction materials, physical blocking such as multi-layer vacuum noise reduction and physical isolation such as the use of sound-absorbing polyurethane cotton materials can achieve the effect of noise reduction. However, under the condition of fixed structure, the present invention only needs a 30-40μm coating to achieve the noise reduction effect, and there is currently no good means of implementation in the prior art.

[0070] Preferably, the thickness of the noise reduction coating is 30-40 μm, for example, it can be 30 μm, 32 μm, 33 μm, 34 μm, 35 μm, 36 μm, 37 μm, 38 μm, 39 μm or 40 μm, but is not limited to the listed values, and other unlisted values ​​within the range are also applicable.

[0071] The coating of the present invention can be formed on the surface of ABS (acrylonitrile-butadiene-styrene copolymer), PC (polycarbonate) or ABS+PC sheet.

[0072] In a fifth aspect, the present invention provides a use of the noise reduction coating described in the fourth aspect in an automobile, preferably in a new energy vehicle.

[0073] Preferably, the noise reduction coating is applied in window seals and / or door seals.

[0074] Compared with the prior art, the present invention has at least the following beneficial effects:

[0075] (1) The preparation method of the porous material provided by the present invention can obtain a porous material with suitable particle size and pore size, and the pores are complex and repeated. When used as a noise reduction material, the efficiency of noise reduction can be greatly improved. In the noise reduction test, the noise reduction performance reaches more than 50%;

[0076] (3) The noise reduction coating provided by the present invention contains porous materials, and only needs to form a coating of a certain thickness to have a better noise reduction effect, without changing the sealing structure, etc., and can be well applied in existing new energy vehicles. BRIEF DESCRIPTION OF THE DRAWINGS

[0077] Figure 1 This is a SEM picture of the noise reduction coating made from the porous material in Application Example 1 of the present invention. DETAILED DESCRIPTION

[0078] For the convenience of understanding the present invention, the present invention lists the following embodiments. It should be understood by those skilled in the art that the embodiments are only to help understand the present invention and should not be regarded as specific limitations of the present invention.

[0079] It should be understood that, in the description of the present invention, the terms "first", "second", etc. are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first", "second", etc. may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "plurality" means two or more.

[0080] Example 1

[0081] This embodiment provides a method for preparing a porous material, the preparation method comprising the following steps:

[0082] (1) Preparation of polyether type waterborne polyurethane dispersion

[0083] IPDI (isophorone diisocyanate) was added to a hydrothermal reaction vessel according to the molar ratio of isocyanate to polyol being controlled at 1.8:1, and polyether polyol (PO3G with a number average molecular weight of 2500 and PTMEG with a number average molecular weight of 2500, the mass ratio of the two being 1:1) and 0.05% of an organotin catalyst (specifically, Evonik T-9) were added; 1.6 times the total mass (the total mass of isocyanate, polyether polyol, organotin catalyst and chain extender) of acetone was then added, and 3.5% of the total mass of DMPA (2,2-dihydroxymethylpropionic acid) was added as a chain extender, and the chain extension reaction was continued at 60°C for 2 hours;

[0084] After the chain extension reaction, deionized water with a mass of 1.3 times that of acetone was added, and ethylenediamine was quickly added to consume the remaining NCO, and then AMP95 was added to adjust the pH to 8.0; the acetone was removed in vacuo, and AMP95 was used again to adjust the pH to 8.0 to obtain a polyether-type waterborne polyurethane dispersion.

[0085] (2) Preparation of porous materials

[0086] According to the molar ratio of water: ethanol: tetraethyl orthosilicate: polyether type waterborne polyurethane = 50:3:1:0.3, tetraethyl orthosilicate is added into a stirrer, and water, ethanol and the polyether type waterborne polyurethane dispersion of step (1) are added, and the mixture is stirred for 12 hours at room temperature (25°C), and then transferred to a high-pressure device, the temperature is controlled at 150°C, and the hydrothermal reaction is continued for 80 hours, and then the pressure is reduced. After centrifugal filtration, the prepared solid powder is washed with water, and then calcined in a muffle furnace at 650°C for 10 hours to obtain a white porous material.

[0087] Example 2

[0088] This embodiment provides a method for preparing a porous material, the preparation method comprising the following steps:

[0089] (1) Preparation of polyether type waterborne polyurethane dispersion

[0090] According to the molar ratio of isocyanate to polyol controlled at 2:1, HMDI (dicyclohexylmethane-4,4'-diisocyanate) was added to the hydrothermal reaction vessel, and polyether polyol (PO3G with a number average molecular weight of 3000 and PTMEG with a number average molecular weight of 3000, the mass ratio of the two was 0.8:1) and 0.1% of the organotin catalyst (Evonik T-9) were added; then 1.5 times the total mass (the total mass of isocyanate, polyether polyol, organotin catalyst and chain extender) of butanone was added, and 3.0% of the total mass of DMBA (2,2-dihydroxymethylbutyric acid) was added as a chain extender, and the chain extension reaction was continued at 80°C for 4 hours;

[0091] After the chain extension reaction, deionized water with a mass of 1.2 times that of butanone was added, and hexamethylenediamine was quickly added to consume the remaining NCO, and then triethylamine was added to adjust the pH to 7.0; the butanone was removed in vacuo, and triethylamine was used again to adjust the pH to 7.0 to obtain a polyether-type waterborne polyurethane dispersion.

[0092] (2) Preparation of porous materials

[0093] According to the molar ratio of water: ethanol: silica sol: polyether waterborne polyurethane = 100:4:1:0.5, silica sol is added to a stirrer, and water, ethanol and the polyether waterborne polyurethane dispersion described in step (1) are added, and the mixture is fully stirred at room temperature (25°C) for 15 hours, and then transferred to a high-pressure device, the temperature is controlled at 170°C, and the hydrothermal reaction is continued for 72 hours, and then the pressure is reduced. After centrifugal filtration, the prepared solid powder is washed with water, and then calcined in a muffle furnace at 700°C for 8 hours to obtain a white porous material.

[0094] Example 3

[0095] This embodiment provides a method for preparing a porous material, the preparation method comprising the following steps:

[0096] (1) Preparation of polyether type waterborne polyurethane dispersion

[0097] HDI (hexamethylene diisocyanate) was added to a hydrothermal reaction vessel according to the molar ratio of isocyanate to polyol being controlled at 4:3, and polyether polyol (PO3G with a number average molecular weight of 2000 and PTMEG with a number average molecular weight of 2000, with a mass ratio of 1.2:1) and 0.06% of an organotin catalyst (Evonik T-9) were added; then, butanone with a total mass (the total mass of isocyanate, polyether polyol, organotin catalyst and chain extender) of 2 times was added, and DMBA (2,2-dihydroxymethylbutyric acid) with a total mass of 5.0% was added as a chain extender, and the chain extension reaction was continued at 75°C for 1 hour;

[0098] After the chain extension reaction, deionized water with a mass of 1.5 times that of butanone was added, and hexamethylenediamine was quickly added to consume the remaining NCO, and then triethylamine was added to adjust the pH to 9.0; butanone was removed in vacuo, and triethylamine was used again to adjust the pH to 9.0 to obtain a polyether-type waterborne polyurethane dispersion.

[0099] (2) Preparation of porous materials

[0100] According to the molar ratio of water: ethanol: white carbon black: polyether type waterborne polyurethane = 15:1:1:0.2, white carbon black is added into a stirrer, and water, ethanol and the polyether type waterborne polyurethane dispersion of step (1) are added, and the mixture is stirred at room temperature (25°C) for 10 hours, and then transferred to a high-pressure device, the temperature is controlled at 140°C, and the hydrothermal reaction is continued for 96 hours, and then the pressure is reduced. After centrifugal filtration, the prepared solid powder is washed with water, and then calcined in a muffle furnace at 600°C for 16 hours to obtain a white porous material.

[0101] Example 4

[0102] This embodiment provides a method for preparing a porous material. The preparation method is the same as that of Embodiment 1 except that the molar ratio of isocyanate to polyol is controlled at 3:1, and thus will not be described in detail.

[0103] Example 5

[0104] This embodiment provides a method for preparing a porous material. The preparation method is the same as that of Embodiment 1 except that the molar ratio of isocyanate to polyol is controlled to be 1:1, and thus will not be described in detail herein.

[0105] Example 6

[0106] This embodiment provides a method for preparing a porous material. The preparation method is the same as that of Example 1, except that PO3G is replaced by PEG with the same number average molecular weight, and PTMEG is replaced by PPG with the same number average molecular weight, and the details are not repeated here.

[0107] Example 7

[0108] The present embodiment provides a method for preparing a porous material. The preparation method is the same as that of Example 1 except that the added amount of polyether waterborne polyurethane in step (2) is only 0.1, i.e., water: ethanol: tetraethyl orthosilicate: polyether waterborne polyurethane = 50:3:1:0.1, and will not be described again.

[0109] Example 8

[0110] The present embodiment provides a method for preparing a porous material. The preparation method is the same as that of Example 1 except that the amount of polyether waterborne polyurethane added in step (2) is as high as 0.7, i.e., water: ethanol: tetraethyl orthosilicate: polyether waterborne polyurethane = 50:3:1:0.7, and will not be described in detail here.

[0111] Comparative Example 1

[0112] This comparative example provides a method for preparing a porous material. The preparation method is the same as Example 1 except that step (1) is not performed and the polyether-type aqueous polyurethane dispersion in step (2) is replaced by a commercially available polyurethane (specifically, Wictobond 374-13 from LANXESS Chemical). The details are not described again.

[0113] Comparative Example 2

[0114] This comparative example provides a method for preparing a porous material. The preparation method is the same as Example 1 except that tetraethyl orthosilicate is replaced by pseudoboehmite in step (2), and the details are not repeated here.

[0115] Test method: BET was used to test the average pore size of the porous material, and a laser particle size analyzer was used to test the particle size of the porous material. The test results of the above embodiments and comparative examples are shown in Table 1.

[0116] Table 1

[0117]

[0118] Application Example 1

[0119] This application example provides a noise reduction coating. In terms of weight percentage, the noise reduction coating includes an aqueous polyurethane dispersion (HYR-2435B), a porous material prepared in Example 1, a wetting agent (Tego270), a defoaming agent (Tego902W), a leveling agent (Tego450) and a film-forming aid (propylene glycol methyl ether), wherein the ratio of aqueous polyurethane dispersion: porous material: wetting agent: defoaming agent: leveling agent: film-forming aid is 100:13:0.2:0.2:0.2:4.

[0120] The SEM image of the noise reduction coating made of the porous material obtained in Example 1 after coating and drying is as follows: Figure 1 As shown, from Figure 1 It can be seen that the average pore diameter of the porous material obtained in this application example is 65 nm, and the pores are deeper and more numerous.

[0121] Application Example 2

[0122] This application example provides a noise reduction coating. The noise reduction coating includes, in parts by mass, an aqueous polyurethane dispersion (HYR-2435B), a porous material prepared in Example 2, a wetting agent (BYK346), a defoaming agent (BYK093), a leveling agent (BYK381) and a film-forming aid (propylene glycol methyl ether acetate), wherein the ratio of aqueous polyurethane dispersion: porous material: wetting agent: defoaming agent: leveling agent: film-forming aid = 100:15:0.1:0.1:0.1:8.

[0123] Application Example 3

[0124] This application example provides a noise reduction coating. The noise reduction coating includes, in parts by mass, an aqueous polyurethane dispersion (Covestro 2611), a porous material prepared in Example 3, a wetting agent (BYK346), a defoaming agent (Tego902W), a leveling agent (BYK381) and a film-forming aid (dipropylene glycol butyl ether acetate), wherein the ratio of aqueous polyurethane dispersion: porous material: wetting agent: defoaming agent: leveling agent: film-forming aid = 100:12:0.3:0.3:0.3:3.

[0125] Application Examples 4 to 8 and Comparative Application Examples 1 to 2

[0126] Application Examples 4 to 8 and Application Comparative Examples 1 to 2 provide a noise reduction coating. Except for using the porous materials in Examples 4 to 8 and Comparative Examples 1 to 2, the noise reduction coating is the same as Application Example 1, and will not be repeated here.

[0127] Application Example 9

[0128] This application example provides a noise reduction coating, which is the same as Application Example 1 except that the number of porous materials prepared in Example 1 is adjusted to 18 parts, that is, the mass ratio of the porous material to the aqueous polyurethane dispersion is 18:1.

[0129] Application Example 10

[0130] This application example provides a noise reduction coating, which is the same as Application Example 1 except that the number of porous materials prepared in Example 1 is adjusted to 8 parts, that is, the mass ratio of the porous material to the aqueous polyurethane dispersion is 8:1.

[0131] Noise reduction performance test: A cube transparent PC box material with a length, width and height of 20*20*20cm was prepared, and the thickness of the PC sheet was 0.8cm. The noise reduction coating prepared in application examples 1 to 10 was sprayed on the six external surfaces of the PC sheet to form a 35μm thick coating. The noise source was placed in the PC box and tested using a noise meter at a distance of two meters from the PC box. The test results of the above application examples and comparative examples are shown in Table 2.

[0132] Table 2

[0133]

[0134] From Table 1 and Table 2, we can see that:

[0135] (1) It can be seen from the application examples 1 to 3 that the preparation method of the porous material provided by the present invention has excellent noise reduction performance, wherein the noise reduction performance can reach more than 50%;

[0136] (2) It can be seen from Examples 1 and 4 to 5 that the regulation of the molar ratio of isocyanate to polyol will affect the molecular weight of the polyether-based aqueous polyurethane dispersion, thereby affecting the pore size of the porous material, resulting in the noise reduction performance being affected. Therefore, the present invention preferably adjusts the molecular weight M of the polyether-based aqueous polyurethane dispersion to 1:1. w Controlling within a reasonable range can further improve the noise reduction effect;

[0137] (3) Based on Example 1 and Example 6, it can be seen that the present invention preferably uses a combination of PO3G and PTMEG as the polyether polyol, which can prepare a more complex pore structure and further improve the noise reduction effect;

[0138] (4) It can be seen from Example 1 and Examples 7 to 8 that the molar ratio of the polyether type aqueous polyurethane dispersion to the silicon source will affect the pore structure of the porous material. The present invention preferably controls the molar ratio of the polyether type aqueous polyurethane dispersion to the silicon source within a reasonable range, which can better improve the noise reduction effect;

[0139] (5) It can be seen from Application Example 1 and Application Examples 9 to 10 that the present invention preferably controls the mass ratio of the porous material in the noise reduction coating within a reasonable range, which can further improve the noise reduction effect; and although the noise reduction performance in Application Example 9 is acceptable, due to the large amount of porous material added, the bonding strength with the substrate is reduced and the coating is easy to fall off.

[0140] (6) It can be seen from the comprehensive application example 1 and the application comparative examples 1-2 that if the polyether type waterborne polyurethane dispersion is not used as a porogen or silicon dioxide is not used as a porous material, the alumina in comparative example 2 will experience pore shrinkage and collapse during the calcination process, and the pore size and particle size will be small. Finally, the noise reduction performance of the application comparative examples 1-2 will be significantly reduced. This shows that the present invention specifically combines the polyether type waterborne polyurethane dispersion and the silicon source to obtain a noise reduction material with excellent performance.

[0141] The present invention illustrates the detailed features of the present invention through the above embodiments, but the present invention is not limited to the above detailed features, that is, it does not mean that the present invention must rely on the above detailed features to be implemented. Those skilled in the art should understand that any improvement of the present invention, equivalent replacement of the technical features selected by the present invention, addition of auxiliary technical features, selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.

Claims

1. A method for preparing a porous material, characterized in that: The preparation method comprises: A polyether type waterborne polyurethane dispersion and a silicon source are mixed and subjected to a hydrothermal reaction, and the obtained hydrothermal reaction product is calcined to obtain a porous material.

2. The preparation method according to claim 1, characterized in that: The molecular weight M of the polyether type waterborne polyurethane in the polyether type waterborne polyurethane dispersion is n 60,000 to 120,000; The molar ratio of the polyether type waterborne polyurethane to the silicon source in the polyether type waterborne polyurethane dispersion is (0.2-0.5):

1.

3. The preparation method according to claim 1 or 2, characterized in that: The raw materials for preparing the polyether type waterborne polyurethane in the polyether type waterborne polyurethane dispersion include: diisocyanate, polyether polyol, catalyst and chain extender; The molar ratio of the diisocyanate to the polyether polyol is 2:1 to 4:3; The number average molecular weight of the polyether polyol is 2000 to 3000; The polyether polyol includes a combination of at least two of polytrimethylene ether glycol, polytetramethylene glycol, polyethylene glycol or polypropylene glycol.

4. The preparation method according to claim 3, characterized in that: The preparation of the polyether type waterborne polyurethane dispersion comprises: The raw material and the second solvent are mixed to carry out a chain extension reaction, and then a third solvent and a capping agent are added, and the first pH adjustment, the solvent removal and the second pH adjustment are carried out in sequence to obtain a polyether type waterborne polyurethane dispersion.

5. The preparation method according to claim 1, characterized in that: The temperature of the hydrothermal reaction is 140 to 170° C.; the time of the hydrothermal reaction is 72 to 96 hours; The calcination temperature is 600-700° C.; the calcination time is 8-16 hours.

6. A porous material, characterized in that: The porous material is prepared by the method for preparing a porous material according to any one of claims 1 to 5; The porous material is a silica filler having pores, and the pores have a pore diameter of 55 to 100 nm; The particle size D50 of the silica filler is 5 to 9 μm.

7. A noise reduction coating, characterized in that: The noise reduction coating comprises the porous material according to claim 6.

8. The noise reduction coating according to claim 7, characterized in that: The noise reduction coating further comprises: a polyurethane dispersion and an additive; The mass ratio of the porous material to the polyurethane dispersion in the noise reduction coating is (12-15):100; The additives include wetting agents, defoamers, leveling agents and film-forming aids; The mass ratio of the additive to the polyurethane dispersion is (3.3-8.9):

100.

9. A noise reduction coating, characterized in that: The noise reduction coating is formed by coating the noise reduction paint according to claim 7 or 8.

10. Use of the noise reduction coating according to claim 9 in an automobile.

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