Perforated plate composite material as well as preparation method and application thereof

Abstract

The invention discloses a perforated plate composite material as well as a preparation method and application thereof, and relates to the field of sound-absorbing materials. The composite material comprises a perforated plate and foamed silicone rubber which are stacked, wherein the foamed silicone rubber comprises silicone rubber, an ABS flame retardant, white carbon black, an AC foaming agent, an organic tin curing agent, a sulfur accelerator, sublimed sulfur, TiO2 and glass fibers. The mechanical strength, ductility and elasticity are greatly improved by vulcanizing the silicone rubber, the density and pore size distribution of the rubber are changed by adding multiple inorganic fillers, the sound absorption effect on low and medium frequency noise is good, meanwhile, the sound absorption efficiency of the sound absorption plate in a medium frequency band or a medium-high frequency band can be guaranteed, the perforated plate is mainly used for sound absorption of medium and high frequencies, and the sound absorption effect is good. Under the combined action of the two components, the requirement for wide-frequency noise absorption can be met, the production cost is low, and the production process is environmentally friendly and harmless.

Description

Technical Field

[0001] The invention relates to the field of sound absorbing materials, and in particular to a perforated plate composite material and a preparation method and application thereof. Background Art

[0002] The existing sound-absorbing materials can achieve a sound absorption efficiency of more than 90% when dealing with medium and high frequency noise, but the sound absorption effect of low frequency or medium and low frequency noise is poor due to the small frequency and large wavelength, and some sound absorption coefficients can only be below 10%. Traditional sound-absorbing materials need to meet the requirement that the material thickness is ≥ 1 / 4 of the noise wavelength to have a good sound absorption effect, but this is not realistic in many practical applications. It is necessary to seek composite materials that can maximize the sound absorption frequency while having high sound absorption efficiency.

[0003] Silicone rubber is a sound-absorbing material that is easily available in daily life and has a low cost. Since it contains a large number of micropores, when sound waves are transmitted to the surface of the material, part of them are reflected by the material, and the remaining part enters the material through the micropores. The friction between the air and the pore wall generates heat and vibration, so that the mechanical energy contained in it is converted into heat energy and dissipated, thereby achieving the effect of sound absorption. However, ordinary silicone rubber alone cannot meet the absorption of medium and low frequency noise, and some projects require foamed rubber to further improve its physical and chemical properties such as strength and ductility. Summary of the invention

[0004] The present invention provides a perforated plate composite material and a preparation method and application thereof, which utilizes perforated plates and foamed silicone rubber to improve the sound absorption efficiency of medium-low and medium-high frequency band noise, can meet the noise absorption of a wider frequency, and improve the physical properties of the composite material to a certain extent.

[0005] In order to solve the above technical problems, one of the purposes of the present invention is to provide a perforated plate composite material, comprising a stacked perforated plate and a foamed silicone rubber, wherein a cavity for accommodating the foamed silicone rubber is opened on one side of the perforated plate, the foamed silicone rubber is located in the cavity, and the foamed silicone rubber comprises the following components in parts by weight:

[0006] Silicone rubber: 50-100 parts;

[0007] ABS flame retardant: 5-10 parts;

[0008] White carbon black: 5-10 parts;

[0009] AC foaming agent: 1-10 parts;

[0010] Organotin curing agent: 1-5 parts;

[0011] Sulfur promoter: 1-5 parts;

[0012] Sublimed sulfur: 1-5 parts;

[0013] TiO2: 1-5 parts;

[0014] Glass fiber: 1-10 parts.

[0015] By adopting the above scheme, the foamed silicone rubber of the present invention contains raw rubber, and the rubber is vulcanized by using sublimated sulfur and a vulcanizing agent. The addition of a vulcanizing agent can increase the stability of the experiment and improve the reaction rate, and can also reduce the amount of sublimated sulfur. When the silicone rubber is foamed, glass fiber is added, and the sound absorption capacity of the silicone rubber can be improved by changing the density of the composite material and its internal composition structure. At the same time, the addition of white carbon black and titanium dioxide fillers can also improve the physical and chemical properties such as stability, thermal conductivity and ductility of the composite material. Compared with unfoamed rubber, the foamed rubber has a better ability to absorb low-frequency noise. The perforated plate has a good ability to absorb medium and high-frequency noise. The main principle is resonance sound absorption. When the noise frequency reaches the resonance frequency, the sound absorption capacity is strong. The foamed silicone rubber has a strong ability to absorb medium and low-frequency noise. By filling the foamed silicone rubber into the cavity of the perforated plate, under the joint action of the two, it can meet the noise absorption of a wider frequency.

[0016] As a preferred solution, the viscosity of the silicone rubber is 1500-5000 mPa·s.

[0017] As a preferred embodiment, the glass fiber is an irregular column with a length of 2-5 cm.

[0018] As a preferred embodiment, the AC foaming agent is azodicarbonamide.

[0019] As a preferred solution, the AC foaming agent has an effective ingredient content of 97-99%.

[0020] As a preferred embodiment, the organic tin curing agent is dibutyltin dilaurate.

[0021] As a preferred embodiment, the sulfur promoter is thiuram and / or guanidine organic matter.

[0022] As a preferred embodiment, the sulfur promoter is at least one of 2-mercaptobenzothiazole, dimethylamine disulfide, and 1,2-ethylenethiourea.

[0023] As a preferred embodiment, the ABS flame retardant is at least one of diethyl aluminum hypophosphite, halloysite nanotubes and zinc borate.

[0024] As a preferred solution, the effective component content of the ABS flame retardant is 90-95%.

[0025] As a preferred embodiment, the S content in the sublimated sulfur is 98.5-99.5%.

[0026] As a preferred solution, the perforated plate has a thickness of 8-12 mm, a perforation diameter of 1-2 mm, and a perforation rate of 2-5%.

[0027] In order to solve the above technical problems, the second object of the present invention is to provide a method for preparing a perforated plate composite material, comprising the following steps:

[0028] (1) Put silicone rubber and ABS flame retardant into a container and stir to mix evenly to obtain a mixture A;

[0029] (2) adding white carbon black, titanium dioxide, glass fiber, AC foaming agent, sublimated sulfur, sulfur promoter and organic tin curing agent to the mixture A, stirring at high speed, and dispersing uniformly by ultrasonication, standing and waiting for curing to be completed, to obtain a mixture B;

[0030] (3) foaming the solidified mixture B, and slicing it after cooling to obtain foamed silicone rubber;

[0031] (4) Filling the foamed silicone rubber into the cavity of the perforated plate to obtain a perforated plate composite material.

[0032] As a preferred embodiment, in step (1), silicone rubber and ABS flame retardant are placed in a container, stirred and mixed at 50-80° C. for 20-40 minutes, and then cooled to room temperature to obtain mixture A.

[0033] As a preferred embodiment, in step (3), the cured mixture B is foamed at 160-200° C. for 1-4 hours.

[0034] Compared with the prior art, the present invention has the following beneficial effects:

[0035] The present application significantly increases the mechanical strength, ductility and elasticity of silicone rubber by vulcanization. The addition of a variety of inorganic fillers can directly change the density and pore size distribution of the rubber, so that it has a good sound absorption effect on medium and low frequency noise, and has better sound absorption ability in the medium and low frequency bands, while also ensuring its sound absorption efficiency in the medium frequency band or medium and high frequency bands. The main principle of perforated plate absorption of high-frequency noise is resonant sound absorption. When the noise frequency reaches the resonant frequency, the sound absorption ability is stronger, and it is mainly used for medium and high frequency sound absorption. By filling the foamed silicone rubber into the cavity of the perforated plate, under the joint action of the two, it can meet the noise absorption of a wider frequency. Compared with traditional materials, it has a larger sound absorption range, and the production cost is lower, and the production process is environmentally friendly and harmless. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 : is a schematic structural diagram of a perforated plate composite material in an embodiment of the present invention;

[0037] Figure 2: are side view and top view of the foamed silicone rubber in Example 2 of the present invention;

[0038] Figure 3 : is the sound absorption efficiency of the perforated plate composite material in Examples 1-3 of the present invention at different frequencies;

[0039] Figure 4 : Sound absorption efficiency of the perforated plate composite materials in Example 2 of the present invention and Comparative Examples 1-6 at different frequencies. DETAILED DESCRIPTION

[0040] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0041] Embodiment 1

[0042] A perforated plate composite material, such as Figure 1 As shown, it includes a stacked perforated plate and foamed silicone rubber, a cavity for accommodating the foamed silicone rubber is formed on one side of the perforated plate, the thickness of the perforated plate excluding the cavity is 10 mm, the diameter of the perforated hole is 1 mm, and the perforation rate is 3%; the thickness of the foamed silicone rubber is 30 mm, and the foamed silicone rubber includes 100 kg of No. 107 silicone rubber, 5 kg of ABS flame retardant, 8 kg of AC foaming agent, 5 kg of organic tin curing agent, 1 kg of vulcanizing agent, 1 kg of sublimated sulfur, 5 kg of of white carbon black powder, 2kg of glass fiber and 5kg of titanium dioxide; among them, the viscosity of No. 107 silicone rubber is 2000mPa·s, the AC foaming agent is azodicarbonamide, the effective ingredient content is 99%, the vulcanization promoter is 2-mercaptobenzothiazole, the ABS flame retardant is diethyl aluminum hypophosphite, the effective ingredient content is 95%, the organic tin curing agent is dibutyltin dilaurate, the S content in the sublimated sulfur is 99%, and the glass fiber is an irregular column with a length of 4cm.

[0043] Embodiment 2

[0044] A perforated plate composite material, such as Figure 1As shown, it includes a stacked perforated plate and foamed silicone rubber, one side of the perforated plate is formed with a cavity for accommodating the foamed silicone rubber, the thickness of the perforated plate excluding the cavity is 10 mm, the perforation diameter is 1 mm, and the perforation rate is 3%; the thickness of the foamed silicone rubber is 30 mm, and the foamed silicone rubber includes 100 kg of No. 107 silicone rubber, 5 kg of ABS flame retardant, 10 kg of AC foaming agent, 5 kg of organic tin curing agent, 1 kg of vulcanizing agent, 1 kg of sublimated sulfur, 5 kg of of white carbon black powder, 5kg of glass fiber and 5kg of titanium dioxide; among them, the viscosity of No. 107 silicone rubber is 1500mPa·s, the AC foaming agent is azodicarbonamide, the effective ingredient content is 99%, the vulcanization promoter is dithiocarbonyl dimethylamine disulfide, the ABS flame retardant is halloysite nanotubes, the effective ingredient content is 95%, the organic tin curing agent is dibutyltin dilaurate, the S content in the sublimated sulfur is 99%, and the glass fiber is an irregular column with a length of 4cm.

[0045] Embodiment 3

[0046] A perforated plate composite material, such as Figure 1 As shown, it includes a stacked perforated plate and foamed silicone rubber, a cavity for accommodating the foamed silicone rubber is formed on one side of the perforated plate, the thickness of the perforated plate excluding the cavity is 10 mm, the diameter of the perforated hole is 1 mm, and the perforation rate is 3%; the thickness of the foamed silicone rubber is 30 mm, and the foamed silicone rubber includes 50 kg of No. 107 silicone rubber, 5 kg of ABS flame retardant, 5 kg of AC foaming agent, 5 kg of organic tin curing agent, 1 kg of vulcanizing agent, 1 kg of sublimated sulfur, 5 kg of of white carbon black powder, 10kg of glass fiber and 5kg of titanium dioxide; among them, the viscosity of No. 107 silicone rubber is 5000mPa·s, the AC foaming agent is azodicarbonamide, the active ingredient content is 99%, the vulcanization promoter is 1,2-ethylenethiourea, the ABS flame retardant is zinc borate, the active ingredient content is 95%, the organic tin curing agent is dibutyltin dilaurate, the S content in the sublimated sulfur is 99%, and the glass fiber is an irregular column with a length of 4cm.

[0047] A method for preparing a perforated plate composite material in the above embodiment comprises the following steps:

[0048] (1) 107 glue and ABS flame retardant were placed in a container, stirred and mixed at 60° C. for 30 min, and then cooled to room temperature to obtain a mixture A;

[0049] (2) adding white carbon black powder, titanium dioxide, glass fiber, AC foaming agent, sublimated sulfur, sulfur promoter and organic tin curing agent to mixture A, stirring at high speed, and dispersing uniformly by ultrasonication, standing and waiting for curing to be completed, to obtain mixture B;

[0050] (3) Foaming the cured mixture B at 180° C. for 2 h, then cooling it at room temperature, and slicing it after 24 h to obtain a finished foamed silicone rubber;

[0051] (4) Filling the foamed silicone rubber into the cavity of the perforated plate to obtain a perforated plate composite material.

[0052] Comparative Example 1

[0053] A perforated plate composite material, wherein each step in the preparation method thereof and the reagents and process parameters used in each step are the same as those in Example 2, except that the AC foaming agent is replaced by an equal amount of CaCO3 foaming agent.

[0054] Comparative Example 2

[0055] A perforated plate composite material, wherein each step in the preparation method thereof and the reagents and process parameters used in each step are the same as those in the second embodiment, except that the glass fiber is replaced by kaolin in an equal amount.

[0056] Comparative Example 3

[0057] A perforated plate composite material, wherein each step in the preparation method thereof and the reagents and process parameters used in each step are the same as those in Example 2, except that an AC foaming agent is replaced by an equal amount of a CaCO3 foaming agent, and glass fiber is replaced by an equal amount of kaolin.

[0058] Comparative Example 4

[0059] A perforated plate composite material, wherein each step in the preparation method thereof and the reagents and process parameters used in each step are the same as those in Example 2, except that the addition amount of white carbon black powder and titanium dioxide is 0.

[0060] Comparative Example 5

[0061] A perforated plate composite material, wherein each step in the preparation method thereof and the reagents and process parameters used in each step are the same as those in Example 2, except that white carbon black powder and titanium dioxide are replaced by glass fiber in equal amounts.

[0062] Comparative Example 6

[0063] A perforated plate composite material, wherein each step in the preparation method thereof and the reagents and process parameters used in each step are the same as those in the second embodiment, except that the addition amount of the AC foaming agent is 0.

[0064] Performance testing

[0065] 1. Combustion performance: The combustion performance of the foamed silicone rubber of the embodiment and the comparative example was tested in accordance with GB / T 10707-2008 "Determination of Combustion Performance of Rubber". The test results are shown in Table 1 below.

[0066] 2. Density: The density of the foamed silicone rubber of the embodiment and the comparative example was tested in accordance with GB / T 533-2008 "Determination of density of vulcanized rubber or thermoplastic rubber". The test results are shown in Table 1 below.

[0067] 3. Tensile strength: The tensile strength of the foamed silicone rubber of the embodiment and the comparative example was tested in accordance with GB / T 528-2009 "Determination of tensile stress-strain properties of vulcanized rubber or thermoplastic rubber". The test results are shown in Table 1 below.

[0068] 4. Elasticity: The elastic modulus of the foamed silicone rubber of the embodiment and the comparative example was tested according to the standard HG / T 3321-2012 "Determination of elastic modulus of vulcanized rubber". The test results are shown in Table 1 below.

[0069] 5. Sound absorption efficiency: According to GB / T 18696.2-2002 "Measurement of sound absorption coefficient and acoustic impedance in acoustic impedance tubes", the sound absorption efficiency of the perforated plate composite materials of the embodiment and the comparative example was tested at different frequencies. The test results are as follows: Figure 3-4 shown.

[0070] Table 1 - Performance test results of foamed silicone rubber in the examples and comparative examples of the present application

[0071] Test items Combustion performance density Tensile Strength Elastic modulus Example 1 FV-0 <![CDATA[0.56g / cm 3 ]]> 0.43Mpa 1.2Mpa Example 2 FV-0 <![CDATA[0.60g / cm 3 ]]> 0.46Mpa 1.5Mpa Example 3 FV-0 <![CDATA[0.62g / cm 3 ]]> 0.42Mpa 1.1Mpa Comparative Example 1 FV-0 <![CDATA[0.55g / cm 3 ]]> 0.40Mpa 0.8Mpa Comparative Example 2 FV-0 <![CDATA[0.64g / cm 3 ]]> 0.42Mpa 1.1Mpa Comparative Example 3 FV-0 <![CDATA[0.64g / cm 3 ]]> 0.50Mpa 1.6Mpa Comparative Example 4 FV-1 <![CDATA[0.57g / cm 3 ]]> 0.40Mpa 0.8Mpa Comparative Example 5 FV-0 <![CDATA[0.65g / cm 3 ]]> 0.57Mpa 1.9Mpa Comparative Example 6 FV-0 <![CDATA[0.83g / cm 3 ]]> 0.64Mpa 2.3Mpa

[0072] like Figure 2 As shown, the surface and interior of the foamed silicone rubber material prepared in Example 2 contain a complex microporous structure, and the micropore size is about 400nm-1000nm, which is formed by the nitrogen generated by the AC foaming agent during the rubber vulcanization process. The microporous structure makes the material have a better sound absorption effect.

[0073] like Figure 3 As shown, the viscosity of the 107 silicone rubber, the amount of glass fiber and AC foaming agent added in the foamed silicone rubber material of Example 2 of the present application will affect the sound absorption band of the foamed silicone rubber material. When the silicone rubber is foamed, adding glass fiber can affect the foaming effect. The sound absorption capacity of the silicone rubber is improved by changing the density of the composite material and its internal composition structure. The perforated plate composite material of Example 2 has the highest sound absorption efficiency for low-frequency noise, indicating that the sound absorption performance is optimal.

[0074] like Figure 4As shown, compared with comparative examples 1-6, Example 2 of the present application uses AC foaming agent to form micropores of different pore sizes during the rubber vulcanization stage, thereby generating a relaxation phenomenon to consume part of the sound energy, which can improve the sound absorption efficiency of medium and low frequency noises. At the same time, glass fiber, white carbon black powder and titanium dioxide are doped into the silicone rubber during the foaming stage. The glass fiber will change the size of the pores in the foamed silicone rubber material, broaden the sound absorption frequency band of the material, and have excellent sound absorption efficiency.

[0075] The specific embodiments described above further illustrate the purpose, technical solutions and beneficial effects of the present invention. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the scope of protection of the present invention. It is particularly pointed out that for those skilled in the art, any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention should be included in the scope of protection of the present invention.

Claims

1. A perforated plate composite material, characterized in that: The invention comprises a stacked perforated plate and a foamed silicone rubber, wherein a cavity for accommodating the foamed silicone rubber is opened on one side of the perforated plate, the foamed silicone rubber is located in the cavity, and the foamed silicone rubber comprises the following components in parts by weight: Silicone rubber: 50-100 parts; ABS flame retardant: 5-10 parts; White carbon black: 5-10 parts; AC foaming agent: 1-10 parts; Organotin curing agent: 1-5 parts; Sulfur promoter: 1-5 parts; Sublimed sulfur: 1-5 parts; TiO2: 1-5 parts; Glass fiber: 1-10 parts.

2. A perforated plate composite material according to claim 1, characterized in that: The viscosity of the silicone rubber is 1500-5000 mPa·s.

3. A perforated plate composite material according to claim 1, characterized in that: The glass fiber is an irregular column with a length of 2-5 cm.

4. A perforated plate composite material according to claim 1, characterized in that: The AC blowing agent is azodicarbonamide.

5. The perforated plate composite material according to claim 1, characterized in that: The organic tin curing agent is dibutyltin dilaurate.

6. The perforated plate composite material according to claim 1, characterized in that: The sulfur-promoting agent is thiuram and / or guanidine organic matter.

7. The perforated plate composite material according to claim 1, characterized in that: The ABS flame retardant is at least one of diethyl aluminum hypophosphite, halloysite nanotubes and zinc borate.

8. The perforated plate composite material according to claim 1, characterized in that: The perforated plate has a thickness of 8-12 mm, a perforation diameter of 1-2 mm, and a perforation rate of 2-5%.

9. A method for preparing a perforated plate composite material according to any one of claims 1 to 8, characterized in that: The following steps are involved: (1) Put silicone rubber and ABS flame retardant into a container and stir to mix evenly to obtain a mixture A; (2) adding white carbon black, titanium dioxide, glass fiber, AC foaming agent, sublimated sulfur, sulfur promoter and organic tin curing agent to the mixture A, stirring at high speed, and dispersing uniformly by ultrasonication, standing and waiting for curing to be completed, to obtain a mixture B; (3) foaming the solidified mixture B, and slicing it after cooling to obtain foamed silicone rubber; (4) Filling the foamed silicone rubber into the cavity of the perforated plate to obtain a perforated plate composite material.

10. The method for preparing a perforated plate composite material according to claim 9, characterized in that: In step (1), silicone rubber and ABS flame retardant are placed in a container, stirred and mixed at 50-80° C. for 20-40 minutes, and then cooled to room temperature to obtain a mixture A; In step (3), the cured mixture B is foamed at 160-200° C. for 1-4 hours.

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