CN1288203C - Method for preparing organic polymer/inorganic mineral composite foamed sound-absorbing material - Google Patents

Abstract

A method for preparing an organic polymer/inorganic mineral composite foam sound-absorbing material. First, 20-50% of resin, 0-50% of rubber, 20-60% of inorganic mineral, 3-5% of hair Foaming agent, 0.5-3% flame retardant and 1-4% stabilizer are stirred and mixed evenly; the above-mentioned mixture is mixed on a mixer at a temperature of 90-140°C for 5-20 minutes to make the required green body ; Chemically foam the finished green body in an oven at a temperature of 150-220° C. for 5-15 minutes. According to the principle that different polymers and inorganic substances have different responses to sound frequencies, the invention adopts a multi-component polymer and inorganic substance blending method, which has the advantages of both organic and inorganic materials, thereby improving the sound absorption performance in the middle and low frequency range.

Description

Preparation method of organic polymer/inorganic mineral composite foam sound-absorbing material

technical field

The invention relates to a preparation method of a sound-absorbing material, in particular to a preparation method of an organic polymer/inorganic mineral composite foam sound-absorbing material which can significantly improve the sound absorption performance of middle and low frequencies.

Background technique

Together with air pollution and water pollution, noise pollution has become the three major environmental hazards in the contemporary world. The control of noise pollution has become an urgent environmental problem, and the use of porous sound-absorbing materials to absorb and reduce noise has become the main technical means at present.

At present, there are three main types of sound-absorbing materials, namely, inorganic porous materials such as microporous glass cloth, metal foam, mineral wool, etc., organic foam polymers such as foam plastics, plant fiber materials, etc., and organic/inorganic composite porous materials. However, although the mechanical properties of inorganic porous materials are good, its low-frequency sound absorption performance is ideal, but the sound absorption performance in the middle and high frequency range is not ideal, it is not easy to construct, and inorganic fiber sound-absorbing materials are easy to scatter, causing certain harm to the human body and the environment , Not suitable for use in places with relatively high environmental and hygienic requirements. Synthetic organic foam polymers have excellent sound absorption performance in the middle and high frequency range and have a wide range of applications, but the sound absorption effect of this type of material in the low frequency range is not obvious, and the mechanical properties are not ideal. The organic/inorganic composite sound-absorbing material is a new type of sound-absorbing material, and it is a new research direction of sound-absorbing materials. It has the advantages of both inorganic sound-absorbing materials and organic foam sound-absorbing materials. High-strength materials with high-efficiency sound-absorbing properties in the , mid-frequency and low-frequency ranges have become the main research goals to meet the actual application requirements.

Contents of the invention

The object of the present invention is to provide a kind of preparation method of organic polymer/inorganic mineral composite foam sound-absorbing material, the sound-absorbing material prepared according to the preparation method of the present invention is a kind of porosity, pore size and its distribution and open porosity can be The foam sound-absorbing material with controlled three-dimensional network structure has the characteristics of wide applicable frequency range and high sound absorption coefficient of medium and low frequencies.

In order to achieve the above-mentioned purpose, the technical solution adopted in the present invention is: firstly mix 20-50% resin, 0-50% rubber, 20-60% inorganic minerals, 3-5% blowing agent, 0.5% ～3% flame retardant and 1～4% stabilizer are stirred and mixed evenly; the above mixture is mixed on a mixer at a temperature of 90～130°C for 8～20 minutes to make the required green body; The green body can be chemically foamed in an oven at a temperature of 160-205° C. for 5-12 minutes.

Resin of the present invention is polyvinyl chloride, polypropylene, polyethylene or polystyrene; Rubber is ethylene propylene rubber, nitrile rubber or butyl rubber; Inorganic mineral is rock wool, expanded perlite, mineral wool or glass wool; The foaming agent is azodicarbonamide, N,N-dinitrosopentamethylenetetramine or 4,4 bisbenzenesulfonyl hydrazide; the flame retardant is magnesium hydroxide, aluminum hydroxide or triphenyl phosphate ester; the stabilizer is dibutyltin dilaurate, butyltin mercaptide, antimony mercaptide compound heat stabilizer or L518 series rare earth multifunctional heat stabilizer.

According to the principle that different polymers and inorganic substances have different responses to sound frequencies, the invention adopts a multi-component polymer and inorganic substance blending method, which has the advantages of both organic and inorganic materials, thereby improving the sound absorption performance in the middle and low frequency range. The sound-absorbing material is a new type of foam sound-absorbing material with a three-dimensional network structure with controllable porosity, pore size and distribution, and open porosity. It has a wide range of applicable frequencies, high sound absorption coefficient at medium and low frequencies, and excellent flame retardancy. , heat insulation, heat and humidity resistance, hygienic safety, low cost, good processability, and secondary processing (such as tailoring), etc., can be widely used in theaters, conference rooms, concert halls, recording studios, gymnasiums Places or environments that require sound absorption and noise reduction, such as highways and highways.

Description of drawings

Fig. 1 is the influence of the sound-absorbing material prepared by the preparation method of the present invention on the sound-absorption coefficient at different thicknesses, wherein the abscissa is the noise frequency, and the ordinate is the sound-absorption coefficient;

Fig. 2 is the impact of the amount of rubber in the sound-absorbing material prepared by the preparation method of the present invention on the sound-absorbing performance of the foam, wherein the abscissa is the noise frequency, and the ordinate is the sound absorption coefficient;

Fig. 3 is the effect of the content of inorganic minerals in the sound-absorbing material prepared by the preparation method of the present invention on the sound-absorption coefficient, wherein the abscissa is the noise frequency, and the ordinate is the sound-absorption coefficient.

Detailed ways

Embodiment 1: at first by mass percentage the magnesium hydroxide of 20% polyvinyl chloride (PVC) and 50% ethylene propylene rubber (EPR), 23% rock wool, 3% azodicarbonamide, 0.5% and 3.5% dibutyltin dilaurate and stir and mix evenly; Mix the above-mentioned mixture on a mixer at a temperature of 90°C for 20 minutes to make the required green body; Chemical foaming takes 5 minutes.

Embodiment 2: first by mass percentage with 50% polypropylene (PP) and 40% expanded perlite, 5% N, N-dinitrosopentamethylenetetramine, 1% aluminum hydroxide and Stir and mix 4% butyltin mercaptide evenly; knead the above mixture on a mixer at 130°C for 15 minutes to make the required green body; chemically foam the prepared green body at a temperature of 205°C in an oven 10 minutes will do.

Embodiment 3: first by mass percent 30% polyethylene (PE) and 5% butyl rubber (IIR), 60% mineral wool, 3% 4,4 bisbenzenesulfonyl hydrazide monoxide, 1% Triphenyl phosphate and 1% mercaptan antimony composite heat stabilizer were stirred and mixed evenly; the above mixture was mixed on a mixer at a temperature of 110°C for 15 minutes to make the required green body; the made green body Chemical foaming in an oven at a temperature of 160°C for 10 minutes is sufficient.

Embodiment 4: first by mass percent, 40% polystyrene (PS) and 32% ethylene propylene rubber (EPR), 20% glass wool, 4% azodicarbonamide, 2% magnesium hydroxide and 2% of the L518 series of rare earth multifunctional heat stabilizers were stirred and mixed evenly; the above-mentioned mixture was kneaded on a mixer at a temperature of 130°C for 8 minutes to make the required green body; Chemical foaming at 200°C for 9 minutes is sufficient.

Embodiment 5: at first 25% polyvinyl chloride (PVC) and 19% acrylonitrile-butadiene rubber (NBR), 47% rock wool, 3% N by mass percent, N-dinitrosopentamethylene Tetramine, 3% aluminum hydroxide and 3% dibutyltin dilaurate were stirred and mixed evenly; the above-mentioned mixture was kneaded for 12 minutes at a temperature of 130° C. on a mixer to make the required green body; the prepared The body can be chemically foamed in an oven at 205°C for 8 minutes.

Embodiment 6: first by mass percent 35% polystyrene (PS) and 27% butyl rubber (IIR), 30% glass wool, 4% 4,4 bisbenzenesulfonyl hydrazide monoxide, 2 % of triphenyl phosphate and 2% of butyltin mercaptide were stirred and mixed evenly; the above mixture was kneaded on a mixer for 13 minutes at a temperature of 110°C to make the required green body; Chemical foaming at 160°C for 12 minutes is sufficient.

Referring to Figure 1, ▲, ● and ■ in the figure represent the sound absorption performance of the organic polymer/inorganic mineral composite material when the thickness is 8mm, 10mm and 12mm respectively. It can be seen from Figure 1 that when the thickness is small, the sound absorption coefficient is higher at high frequencies and lower at low frequencies. As the thickness increases, the sound absorption coefficient at high frequencies gradually decreases and the sound absorption coefficient at low frequencies gradually decreases. rise. It is mainly due to the difference in acoustic impedance caused by the difference in thickness.

Referring to Figure 2, ■, ●, ▲,  in the figure represent the sound absorption performance of the organic polymer/inorganic mineral composite material when the rubber (such as EPR) content is 0%, 5%, 10% and 15%, respectively. It can be seen from Figure 2 that as the amount of rubber increases, the sound absorption factor at frequencies below 1000 Hz tends to increase, while the sound absorption factor at frequencies above 1000 Hz shows a decreasing trend. Compared with the foam without rubber, EPR can improve the comprehensive sound absorption performance (expressed by the average sound absorption factor) of foam materials. The reasons are: ① At room temperature, EPR is in a high elastic state. Some sonic energy; ②The segments and side groups on the rubber macromolecular chains move under the action of sonic waves. This kind of movement has a large frictional resistance within the molecule and/or between molecules, and consumes a lot of sonic energy. Therefore, rubber is conducive to the improvement of the comprehensive sound absorption performance of the material. Since the glass transition temperature of rubber is much lower than that of PVC, the energy that causes rubber deformation and the movement of molecular segments is relatively low. Therefore, within a certain range, the increase in the amount of rubber in the composite material makes the relatively low frequency The sound absorption factor is significantly improved. But it is not that the greater the amount of rubber, the better the overall sound absorption performance of the material, because when the amount of EPR is too large, the viscosity of the system will be too small during the foaming process, and the foaming gas will increase rapidly with the rapid decomposition of the foaming agent. , the cell grows rapidly, and the cell wall also rapidly becomes thinner, causing the adjacent cells to merge, the cell structure deteriorates, the porosity decreases, and the sound absorption performance of the material also decreases. When the foaming is serious, it can also lead to the collapse of the cells, resulting in a sharp decrease in the porosity of the material, which seriously affects the sound absorption performance of the material.

Referring to Figure 3, ■, ●, ▲ represent the sound absorption performance of the organic polymer/inorganic mineral composite material when the amount of inorganic minerals (such as rock wool) is 35%, 45%, and 55%, respectively. It can be seen from Figure 3 that the comprehensive sound absorption performance of 45% rock wool is better; with the increase of the amount of rock wool, in the range below 800Hz, the sound absorption coefficient increases first and then decreases, and in the range above 800Hz Basically an increasing trend. This is determined by the nature of rock wool. There are two functions of rock wool in this system: 1. Because of its excellent sound absorption performance, its addition will undoubtedly improve the sound absorption performance; 2. Rock wool Cotton is also an inorganic fiber, and its addition will increase the viscosity and hardness of the foaming melt, making it difficult to foam, and it is not easy to homogenize during mixing, making the contact between the phase and interface worse. The gas decomposed by the foaming agent escapes out of the product along the rock wool fiber, resulting in a decrease in porosity, resulting in a decrease in sound absorption performance, and easily forming larger bubbles, causing the product to collapse and the surface to be uneven, affecting the apparent quality. Therefore, the impact of rock wool on the sound absorption performance of materials mainly depends on which of the above-mentioned contradictions is dominant. The results in Figure 3 may be the result of different void ratios brought about by different rock wool dosages.

Table 1 is the comparison of the sound absorption performance of organic polymer/inorganic mineral composite sound-absorbing materials with polymer foam and mineral sound-absorption performance material name Thickness/cm Sound absorption coefficient at each frequency (Hz) Average sound absorption coefficient 250 500 1000 2000 4000 A phenolic foam polyurethane foam 222.5 0.150.10.07 0.520.260.11 0.60.550.16 0.780.520.31 0.810.620.83 0.5720.410.296 Rock wool C polyether vinyl foam 2.511 0.090.080.04 0.240.130.06 0.570.230.08 0.930.440.18 0.970.750.29 0.560.3260.13

A and C are organic polymer/inorganic mineral composite sound-absorbing materials prepared by the present invention

In order to test the sound absorption performance of the material obtained in the present invention, it is compared with the sound absorption performance of some other sound absorption materials, as shown in Table 1. As can be seen from Table 1, the sound absorption properties of the materials A and C obtained in the present invention are superior to other foamed polymer materials and inorganic mineral rock wool at the same thickness, especially the sound absorption performance at medium and low frequencies is very high: at 250-500Hz Within the range, the sound absorption coefficient is almost 2 times that of other materials. Under the same conditions, its average sound absorption coefficient is much higher than other materials. It can be seen that the sound-absorbing material obtained in the present invention is a new type of sound-absorbing material with high sound-absorbing coefficient and excellent sound-absorbing performance.

The pore size and distribution, porosity and open porosity of the sound-absorbing material prepared according to the preparation method of the present invention are easy to control, the density is low, less than 600Kg/m ³ , organic-inorganic combination, and high sound absorption in a wide frequency range Performance, in the range of 100 ~ 2000Hz has a high sound absorption effect, the average sound absorption coefficient is above 0.5, which is more than 40% higher than that of ordinary foam plastics, especially in the range of medium and low frequencies; it has high mechanical properties, Compressive strength greater than 5MPa; excellent forming and processing performance, can be made into products of various complex shapes, low cost, good secondary processing performance, easy to cut, convenient for construction; flame retardant, anti-mildew, aging resistance and heat resistance good.

Claims (6)

1, a kind of preparation method of organic polymer/inorganic mineral composite foamed sound-absorbing material is characterized in that:

1) at first by mass percentage 20～50% resin, 0～50% rubber, 20～60% inorganic mineral, 3～5% whipping agent, 0.5～3% fire retardant and 1～4% stablizer are mixed;

Said inorganic mineral is rock wool, pearlstone, mineral wool or glass wool;

2) above-mentioned mixture was being made required base substrate in mixing 8～20 minutes on the mixing roll under 90～130 ℃ of temperature;

3) with the base substrate made in baking oven under 160～205 ℃ of temperature chemical foaming got final product in 5～12 minutes.

2, the preparation method of organic polymer/inorganic mineral composite foamed sound-absorbing material according to claim 1 is characterized in that: said resin is polyvinyl chloride, polypropylene, polyethylene or polystyrene.

3, the preparation method of organic polymer/inorganic mineral composite foamed sound-absorbing material according to claim 1 is characterized in that: said rubber is ethylene-propylene rubber(EPR), paracril or isoprene-isobutylene rubber.

4, the preparation method of organic polymer/inorganic mineral composite foamed sound-absorbing material according to claim 1 is characterized in that: said whipping agent is Cellmic C 121, N, N-dinitroso five methyne tetramines or 4,4 one bis oxide benzol sulfohydrazides.

5, the preparation method of organic polymer/inorganic mineral composite foamed sound-absorbing material according to claim 1 is characterized in that: said fire retardant is magnesium hydroxide, aluminium hydroxide or triphenylphosphate.

6, the preparation method of organic polymer/inorganic mineral composite foamed sound-absorbing material according to claim 1 is characterized in that: said stablizer is dibutyl tin laurate, thiol-butyl tin, mercaptan antimony composite thermal stabilizer or L518 serial rare-earth multifunctional heating stablizer.

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