Energy-saving and noise-reducing composite material, preparation method and application thereof

Abstract

The present application relates to the technical field of building materials, in particular to an energy-saving and noise-reducing composite material and its preparation method and application. The energy-saving and noise-reducing composite material comprises a tightly bonded light-reflecting layer and a base layer; the base layer is formed by pressing and curing the base material; the base material is composed of 1-3mm particle size aggregate, 3-5mm particle size aggregate and 2-4mm long wollastonite mineral fibers; the light-reflecting layer is formed by curing the light-reflecting material; the light-reflecting material is composed of 0.1-0.3mm particle size quartz sand, 50-100um particle size pearl powder and 100-150um particle size glass sphere microbead powder; the composite material has irregular through holes with a pore size covering 0.2-1mm. The preparation method and application of the above energy-saving and noise-reducing composite material. The present application solves the technical problems of noise reduction and energy saving of tunnel closed reverberation, and cooperatively realizes high diffuse reflectivity of tunnel wall material and reduction of reverberation noise, thereby improving the comfort and safety of the tunnel closed space.

Description

Technical Field

[0001] This invention relates to the field of building materials technology, specifically to an energy-saving and noise-reducing composite material, its preparation method, and its application. Background Technology

[0002] As enclosed transportation spaces, tunnels present significantly different acoustic and optical environments compared to open roads. Acoustically, noise repeatedly reflects off the tunnel walls, creating a reverberant sound field that leads to a significant increase in noise level and a prolonged reverberation time. This not only severely impacts the auditory comfort of drivers and passengers but also poses traffic safety hazards; according to traffic department statistics, noise interference causes 28% of tunnel traffic accidents. Optically, tunnels lack natural light and rely entirely on artificial lighting, resulting in enormous energy consumption. Traffic operation data shows that lighting energy consumption accounts for 35-40% of tunnel operating costs, with light source utilization rates below 50%. Therefore, developing a low-cost, functional wall material that can simultaneously address reverberation noise within tunnels and improve lighting efficiency has become a key research focus in this field.

[0003] Currently, the main means of improving the acoustic environment inside tunnels is to install traditional sound-absorbing panels or sound-absorbing linings on the walls. These materials usually focus on sound absorption performance, but their surface optical properties (such as low reflectivity or specular reflection) are often not conducive to the efficient use of light and cannot contribute to energy conservation in lighting, thus having a relatively simple function.

[0004] In the field of road functional materials, there are also some materials in the existing technology that have both acoustic and optical functions.

[0005] For example, in the patent technology solution with publication number CN108688245A, through the concave-convex texture structure and the through-hole design that penetrates the protective layer, reflective material layer and substrate thickness direction, the reflectivity is more than 85%, but the noise reduction effect in the reverberation environment is only 10dB at most, which does not meet the increasingly high noise reduction requirements of tunnel reverberation environment.

[0006] The patent solution published in CN120272109A provides an anti-skid, noise-reducing porous road hot-melt material. It uses bio-based resin as the base material and adds ultra-fine bamboo fiber with honeycomb pores and polyurethane elastomer as noise-reducing materials, along with glass beads of different sizes to provide retroreflective effects. This technology aims to improve the noise reduction, anti-skid performance, and nighttime reflective visibility of road markings. Test data shows that its coating has a certain sound absorption coefficient and sound insulation. However, this technology has the following limitations: 1. It addresses the marking problem of open roads, and its core optical performance lies in retroreflection, which contradicts the optical mechanism of tunnel walls requiring uniform diffuse reflection of light throughout the space to reduce light energy consumption; 2. The sound absorption coefficient (α) and sound insulation (R) provided are material parameters measured under laboratory conditions; however, tunnel noise reduction focuses more on the insertion loss or reverberation time reduction brought about by the material in the actual tunnel reverberation field. Materials with good absorption coefficients may not achieve excellent overall noise reduction effects in the specific sound field of a tunnel. 3. It emphasizes the environmental friendliness of bio-based materials (easy to degrade), but for tunnels, the wall materials need long-term stability. Premature degradation will shorten the maintenance cycle and increase costs.

[0007] Therefore, there is an urgent need in this field for a new type of composite material specifically designed for the inner walls of tunnels, which must be able to overcome the above limitations and, while meeting the requirements of tunnel engineering for material durability, safety, and low cost, synergistically achieve high diffuse reflectivity to improve lighting energy efficiency and significantly reduce reverberation noise in tunnels, thereby comprehensively improving the comfort and safety of the tunnel environment. Summary of the Invention

[0008] This invention provides an energy-saving and noise-reducing composite material, its preparation method, and its application. It solves the technical problems of noise reduction in tunnel enclosures and energy saving in lighting, and synergistically achieves high diffuse reflectivity of tunnel wall materials and reduces reverberation noise, thereby improving the comfort and safety of tunnel enclosures.

[0009] The first objective of this invention is to provide an energy-saving and noise-reducing composite material.

[0010] To achieve the first objective of this invention, an energy-saving and noise-reducing composite material is provided, comprising a reflective layer and a matrix layer tightly bonded from top to bottom;

[0011] The matrix layer is formed by pressing and curing a matrix material, during which irregular pores naturally form from top to bottom along the thickness direction of the matrix layer; the matrix material is composed of the following raw materials in parts by weight:

[0012] 35-65 parts of aggregate with a particle size of 1-3mm;

[0013] 10-15 parts of aggregate with a particle size of 3-5mm;

[0014] 5-10 parts of wollastonite mineral fibers, 2-4 mm in length;

[0015] 5-10 parts toughening agent;

[0016] 30-40 parts adhesive; and

[0017] Hardener 0.3-0.8 parts;

[0018] The reflective layer is formed by coating a reflective material onto the surface of a substrate layer and curing it. During the forming process, reflective pores naturally form from top to bottom, penetrating the thickness direction of the reflective layer. The reflective material is composed of the following raw materials in parts by weight:

[0019] 10-20 parts of quartz sand with a particle size of 0.1-0.3 mm;

[0020] 5-10 parts of pearlescent powder with a particle size of 50-100μm;

[0021] 20-25 parts of glass microsphere powder with a particle size of 100-150 μm; and

[0022] 40-65 parts of acrylic emulsion;

[0023] The irregular pores are interconnected with the pores of the reflective layer to form irregularly sized through holes; the diameter of the irregularly sized through holes is in the range of 0.2 mm to 1 mm.

[0024] In one specific embodiment of the present invention, the bulk porosity of the energy-saving and noise-reducing composite material is 20-25%.

[0025] In one specific embodiment of the present invention, the irregular aperture through-hole includes a natural gradient through-hole; the aperture of the natural gradient through-hole gradually increases from aperture A to aperture B along the thickness direction of the energy-saving and noise-reducing composite material from top to bottom; wherein, aperture A refers to the aperture diameter of the natural gradient through-hole on the upper surface of the reflective layer, which is 0.2 to 0.5 mm; aperture B refers to the aperture diameter of the natural gradient through-hole on the lower surface of the substrate layer, which is 0.5 to 1 mm.

[0026] Natural gradient through-holes are a special type of irregularly sized through-hole structure that naturally forms after the aggregates of different particle sizes in the matrix layer are pressed and molded. The entire structure extends through the matrix layer from top to bottom along the thickness direction, and the diameter of the pores gradually increases from top to bottom along the matrix layer. Because the pores of the natural gradient through-holes pass through the non-adhesive areas between aggregates of different particle sizes, the pores of the natural gradient through-holes extend from top to bottom along the thickness direction of the matrix layer, with local natural variations. It is precisely because of the special pore structure of the natural gradient through-holes that, on the one hand, the sound waves inside the pores are prevented from returning to the reverberation chamber from the openings on the surface of the reflective layer, and on the other hand, the sound waves entering the pores are dissipated inside the natural gradient through-holes. Therefore, the composite material obtained by pressing and molding irregularly sized aggregates has a further improvement effect on tunnel reverberation noise reduction.

[0027] In one specific embodiment of the present invention, the pressure for pressing and curing is 15-25 MPa.

[0028] In one specific embodiment of the present invention, the aggregate with a particle size of 1-3 mm includes quartz sand with a particle size of 1-3 mm, natural modified mineral powder with a particle size of 1-3 mm, and inorganic non-metallic raw materials with a particle size of 1-3 mm; wherein, the weight ratio of quartz sand with a particle size of 1-3 mm, natural modified mineral powder with a particle size of 1-3 mm, and inorganic non-metallic raw materials with a particle size of 1-3 mm is (15-25):(10-20):(10-20).

[0029] In one specific embodiment of the present invention, the quartz sand with a particle size of 1-3 mm contains SiO2 ≥ 98 wt% and mud ≤ 0.5 wt%; the natural modified mineral powder with a particle size of 1-3 mm is calcium-based modified dolomite powder, wherein CaCO3 and MgCO3 ≥ 95 wt%, and its modification is performed using zinc stearate, with the amount of zinc stearate being 1.5 wt%; the inorganic non-metallic raw material with a particle size of 1-3 mm is metakaolin, with SiO2 and Al2O3 ≥ 90 wt% and its loss on ignition ≤ 1.5 wt%.

[0030] In one specific embodiment of the present invention, the 2-4 mm long wollastonite mineral fibers have a needle-like ratio ≥80% and a whiteness ≥90%; the 3-5 mm diameter aggregate is recycled fiberglass granules, composed of glass fiber and unsaturated polyester resin, with a glass fiber content of 30% and an unsaturated polyester resin purity ≥85%; the toughening agent is a modified plastic, which is formed by blending and modifying PP and PE in a weight ratio of 7:3, and has a melt index of 10-15 g / 10 min; the binder is an epoxy resin with an epoxy value of 0.41-0.47 eq / 100 g; the curing agent is polyamide 650, with an amine value of 200-240 mg KOH / g and a viscosity of 2000-4000 cP at 25°C; the 50-100 μm diameter pearlescent powder has a refractive index ≥1.9; and the 100-150 μm diameter glass microsphere powder has a light transmittance ≥92%.

[0031] In one specific embodiment of the present invention, the acrylic emulsion has a solid content of ≥45% and a viscosity of 500-1000 cP.

[0032] The second objective of this invention is to provide a method for preparing the above-mentioned energy-saving and noise-reducing composite material.

[0033] To achieve the second objective of this invention, the preparation method of the above-mentioned energy-saving and noise-reducing composite material includes the following steps:

[0034] a. The matrix material is mixed according to the weight proportions, and then pressed and cured to form the matrix layer;

[0035] b. Take the reflective material according to the weight proportions, mix them, and coat them on the upper surface of the substrate layer in step a. After curing and molding, the energy-saving and noise-reducing composite material is obtained.

[0036] In one specific embodiment of the present invention, the mold is made of Cr12MoV and has a surface roughness Ra≤0.8μm.

[0037] A third objective of this invention is to provide the application of the above-mentioned energy-saving and noise-reducing composite material in the preparation of a brightening and noise-reducing material for underground space walls.

[0038] The walls of underground spaces include tunnel walls.

[0039] The beneficial effects of this invention are:

[0040] 1. The energy-saving and noise-reducing composite material provided by this invention achieves an overall noise reduction of ≥15dB in reverberation chamber testing, demonstrating excellent acoustic performance. This effect is mainly attributed to the naturally formed, interconnected, irregularly sized through-hole structure within the material. This structure effectively enhances the noise reduction and attenuation effect within the reverberation chamber. Compared to regular pore structures that require precision machining to achieve noise reduction, the irregular through-holes of this invention further improve sound absorption efficiency, and the irregular pores are naturally formed during the pressing and curing process, reducing the manufacturing cost of the energy-saving and noise-reducing composite material.

[0041] 2. The energy-saving and noise-reducing composite material of this invention achieves excellent noise reduction while maintaining a high diffuse reflectance similar to existing technologies. To achieve this technical balance, the reflective material of this invention ensures that even on a naturally formed, well-permeable irregular porous structure, the reflective layer can still form a complete surface with high diffuse reflectance, thus solving the technical problem that high porosity structures usually lead to increased light scattering and decreased diffuse reflectance. This makes the material of this invention particularly suitable for occasions with high requirements for indoor lighting and sound environment, achieving a true synergy between the two major functions of "energy saving" and "noise reduction".

[0042] 3. The production process of the composite material of this invention has significant economic advantages. Its core noise-reducing through-hole structure is naturally formed during the material molding process, eliminating the need for subsequent secondary processing steps such as mechanical drilling or laser drilling. This greatly simplifies the production process, reduces equipment investment and energy consumption, significantly lowers production costs, and lays the foundation for large-scale commercial application.

[0043] 4. The energy-saving and noise-reducing composite material of this invention naturally forms irregularly sized through-pores, controlling the bulk porosity of the composite material within the range of 20% to 25%. This ensures excellent acoustic performance while maintaining sufficient mechanical strength and dimensional stability. This porosity range avoids the strength degradation problem caused by excessively high porosity and also prevents the noise reduction effect from being affected by excessively low porosity, giving the product a combination of high diffuse reflection, high noise reduction performance, and high reliability.

[0044] 5. The reflective layer of this invention naturally forms a textured surface, which not only improves the diffuse reflectivity of the reflective layer surface but also has a certain effect on breaking up and reducing the noise of sound waves. Attached Figure Description

[0045] Appendix Figure 1 This is a partial cross-sectional schematic diagram of the energy-saving and noise-reducing composite material of the present invention;

[0046] Appendix Figure 2 This is a schematic diagram of the matrix material laying process in the composite material preparation method of this invention.

[0047] Appendix Figure 3 This is a schematic diagram of the pressing and curing molding process in the composite material preparation method of this invention.

[0048] Appendix Figure 4 This is a schematic diagram of the coating of reflective material in the composite material preparation method of a specific embodiment of the present invention.

[0049] The attached diagram lists the components represented by each number as follows:

[0050] 1. Substrate layer; 2. Reflective layer; 3. Lower mold; 4. Hopper; 5. Upper mold; 6. Spraying device; 7. Irregularly sized through holes; 71. Hole diameter A; 72. Hole diameter B; 8. Recycled fiberglass granules; 9. Quartz sand with a particle size of 1-3 mm; 10. Wollastonite mineral fibers with a length of 2-4 mm. Detailed Implementation

[0051] Based on the appendix Figure 1An energy-saving and noise-reducing composite material includes a reflective layer 2 and a matrix layer 1 tightly bonded from top to bottom; the matrix layer 1 is formed by pressing and curing a matrix material, and irregular pores naturally form from top to bottom along the thickness direction of the matrix layer 1 during the forming process; the matrix material is composed of the following raw materials in parts by weight:

[0052] 35-65 parts of aggregate with a particle size of 1-3mm;

[0053] 10-15 parts of aggregate with a particle size of 3-5mm;

[0054] 5-10 parts of wollastonite mineral fibers, 2-4 mm in length;

[0055] 5-10 parts toughening agent;

[0056] 30-40 parts adhesive; and

[0057] Hardener 0.3-0.8 parts;

[0058] The reflective layer 2 is formed by coating a reflective material onto the surface of the substrate layer 1 and curing it, and during the forming process, reflective pores that penetrate the thickness direction of the reflective layer 2 are naturally formed; the reflective material is composed of the following raw materials in parts by weight:

[0059] 10-20 parts of quartz sand with a particle size of 0.1-0.3 mm;

[0060] 5-10 parts of pearlescent powder with a particle size of 50-100μm;

[0061] 20-25 parts of glass microsphere powder with a particle size of 100-150 μm; and

[0062] 40-65 parts of acrylic emulsion;

[0063] The irregular pores are interconnected with the pores of the reflective layer to form irregularly sized through holes 7; the diameter of the irregularly sized through holes 7 ranges from 0.2 mm to 1 mm.

[0064] In some examples, the bulk porosity of the energy-saving and noise-reducing composite material is 20–25%. The bulk porosity is measured using a mercury porosimeter.

[0065] In some examples, the irregularly sized through-holes 7 include natural gradient through-holes; the diameter of the natural gradient through-holes gradually increases from A 71 to B 72 along the thickness direction of the energy-saving and noise-reducing composite material from top to bottom; A 71 refers to the orifice diameter of the natural gradient through-hole on the upper surface of the reflective layer 2, which is 0.2–0.5 mm, and B 72 refers to the orifice diameter of the natural gradient through-hole on the lower surface of the matrix layer 1, which is 0.5–1 mm. These natural gradient through-holes are formed naturally under a pressing pressure of 15–25 MPa, utilizing the particle size difference of the matrix material raw materials and the spatial steric hindrance between the aggregates, resulting in an irregularly sized, gradually increasing pore size structure.

[0066] In some examples, the compression molding pressure is 15–25 MPa. Under this pressure, the aggregates of different particle sizes in the matrix material are distributed and stacked differently in the molded matrix layer due to differences in particle size and specific gravity. Simultaneously, irregular pores with irregular pore sizes are formed due to the differences in aggregate particle size. The presence of these irregular pores causes sound waves to scatter through the small pores on the upper surface of the composite material. Sound waves enter the irregular pores, where the amplitude is weakened at medium-sized pores, while low-frequency noise is absorbed through the large pores on the lower surface of the composite material. This achieves sound wave attenuation / reduction, thus reducing noise in the reverberation environment.

[0067] In some examples, the aggregate with a particle size of 1-3 mm includes quartz sand 9 with a particle size of 1-3 mm, natural modified mineral powder with a particle size of 1-3 mm, and inorganic non-metallic raw materials with a particle size of 1-3 mm; wherein, the weight ratio of quartz sand 9 with a particle size of 1-3 mm, natural modified mineral powder with a particle size of 1-3 mm, and inorganic non-metallic raw materials with a particle size of 1-3 mm is (15-25):(10-20):(10-20).

[0068] It should be noted that: 1-3mm quartz sand 9 refers to quartz sand with a particle size distribution of 1mm to 3mm, which is a mixture of the oversize material from a 1mm sieve and the undersize material from a 3mm sieve, based on particle size; 1-3mm natural modified mineral powder refers to natural modified mineral powder with a particle size distribution of 1mm to 3mm, which is a mixture of the oversize material from a 1mm sieve and the undersize material from a 3mm sieve, based on particle size; 1-3mm inorganic non-metallic raw materials refers to inorganic non-metallic raw materials with a particle size of 1mm to 3mm, which is a mixture of the oversize material from a 1mm sieve and the undersize material from a 3mm sieve, based on particle size; and 3-5mm aggregate refers to recycled fiberglass granules with a particle size of 3mm to 5mm, which is a mixture of the oversize material from a 3mm sieve and the undersize material from a 5mm sieve, based on particle size.

[0069] In some examples, the 1-3 mm quartz sand 9 contains SiO2 ≥ 98 wt% and mud ≤ 0.5 wt%; the 1-3 mm natural modified mineral powder is calcium-based modified dolomite powder, wherein CaCO3 and MgCO3 ≥ 95 wt%, and its modifier is zinc stearate, with an addition amount of 1.5 wt%; the 1-3 mm inorganic non-metallic raw material is metakaolin, with SiO2 and Al2O3 ≥ 90 wt% and its loss on ignition ≤ 1.5 wt%.

[0070] In some examples, the needle-like rate of 2-4 mm long wollastonite mineral fibers 10 is ≥80%, and the whiteness is ≥90%; the aggregate with a particle size of 3-5 mm is recycled fiberglass granules 8 with a particle size of 3-5 mm, which is composed of glass fiber and unsaturated polyester resin, with a glass fiber content of 30% and an unsaturated polyester resin purity of ≥85%; the toughening agent is a modified plastic, which is made by blending and modifying PP and PE in a weight ratio of 7:3, and its melt index is 10-15 g / 10 min; the binder is epoxy resin with an epoxy value of 0.41-0.47 eq / 100 g; the curing agent is polyamide 650, with an amine value of 200-240 mg KOH / g and a viscosity of 2000-4000 cP at 25℃; the refractive index of pearl powder with a particle size of 50-100 μm is ≥1.9; and the light transmittance of glass microspheres with a particle size of 100-150 μm is ≥92%.

[0071] It should be noted that the 1-3mm diameter quartz sand 9, as the aggregate skeleton of the matrix layer 1, not only serves as a basic guarantee for the compressive strength of the composite material, but also allows for the natural formation of irregularly sized through holes 7 during pressing and curing, absorbing sound waves; the 1-3mm diameter natural modified mineral powder is used to adjust the pore distribution of the matrix layer 1 and reduce the material cost of the energy-saving and noise-reducing composite material; the 1-3mm diameter inorganic non-metallic raw materials enhance the weather resistance and adhesion of the energy-saving and noise-reducing composite material; the 2-4mm length wollastonite mineral fiber 10 improves the flexural strength of the energy-saving and noise-reducing composite material sheet; the recycled fiberglass granules 8 are supported by recycled fiberglass, which can reduce the raw material cost of the energy-saving and noise-reducing composite material; the modified plastic composed of PP and PE can improve the toughness of the energy-saving and noise-reducing composite material; the adhesive bonds the various raw materials of the matrix layer 1; and the curing agent accelerates the curing of the adhesive.

[0072] In some instances, the acrylic emulsion has a solids content of ≥45% and a viscosity of 500–1000 cP.

[0073] The preparation method of the above-mentioned energy-saving and noise-reducing composite material includes the following steps:

[0074] a. The matrix material is mixed according to the weight proportions and then pressed into shape to obtain the matrix layer;

[0075] b. Take the reflective material according to the weight proportions, mix them, and coat them on the upper surface of the substrate layer in step a. After curing and molding, the energy-saving and noise-reducing composite material is obtained.

[0076] As attached Figures 2 to 4 As shown, the matrix material is mixed in the hopper 4 and then placed in the cavity of the lower mold 3; the upper mold 5 presses down, providing a pressing pressure of 15-25 MPa, and after curing, a matrix layer 1 is formed; reflective material is coated on the surface of the pressed matrix layer 1 using a spraying device 6, and after drying, dehydration and curing, an energy-saving and noise-reducing composite material is obtained.

[0077] In some instances, the pressing time is 3 to 5 minutes; during the pressing process at a pressure of 15 to 25 MPa, the temperature of the lower mold 3 is controlled at 40 to 50°C, which is beneficial to promote the initial curing of the pressed base layer 1, facilitates the demolding of the base layer 1, and improves production efficiency.

[0078] In some instances, the final thickness of the reflective layer 2 is controlled between 0.3 and 0.5 mm; the thickness of the reflective layer 2 is measured using a wet film thickness gauge.

[0079] In some instances, the adhesion of the reflective layer 2 of the finished energy-saving and noise-reducing composite material to the surface of the substrate layer 1 meets the Class 1 requirement of GB / T9286~1998 "Cross-cut test of paint and varnish film", that is, a small amount of coating peels off at the intersection of the cuts, but the cross-cut area is not significantly affected by more than 5%.

[0080] The energy-saving and noise-reducing composite material prepared by this invention has a natural uneven texture with a height difference of 0.3 to 0.8 mm on the upper surface of the reflective layer 2, which is formed by curing after coating. This is one of the reasons why the energy-saving and noise-reducing composite material has high diffuse reflection efficiency.

[0081] The above-mentioned energy-saving and noise-reducing composite material is used in the preparation of brightening and noise-reducing materials for underground space walls; preferably, the underground space wall is the wall of a vehicle tunnel.

[0082] To further demonstrate the role of the energy-saving and noise-reducing composite material of the present invention in improving reverberation noise reduction in tunnel closures and energy saving in lighting, the following embodiments and comparative examples are provided:

[0083] In the following examples and comparative examples, the bulk porosity of the energy-saving and noise-reducing composite material was detected by a mercury porosimeter; its diffuse reflectance was detected by a spectrophotometer in the visible light band of 380–780 nm; its noise attenuation was tested according to the test method of "sound absorption A2 of a room with a reverberation chamber containing a specimen" in GB / T20247–2006 "Acoustic Reverberation Chamber Sound Absorption Test", and the noise attenuation was tested in a reverberation chamber containing a specimen. The noise levels before and after actual application on the walls of a specific enclosed tunnel were also tested to re-measure the effect of the energy-saving and noise-reducing composite material in actual application; its mechanical properties, compressive strength and flexural strength, were tested according to the test methods of compressive strength and flexural strength in GBT3810.4-2016 "Ceramic Tile Test Methods Part 4: Determination of Modulus of Fracture and Breaking Strength".

[0084] Example 1

[0085] This embodiment provides a method for preparing an energy-saving and noise-reducing composite material, including the following steps:

[0086] (1) Raw material ratio:

[0087] Matrix layer raw materials: 20 parts by weight of quartz sand with a particle size of 1-3 mm, 15 parts by weight of calcium-modified dolomite powder with a particle size of 1-3 mm, 15 parts by weight of metakaolin with a particle size of 1-3 mm, 8 parts by weight of wollastonite mineral fiber with a length of 2-4 mm, 12 parts by weight of recycled fiberglass granules with a particle size of 3-5 mm, 8 parts by weight of PP:PE=7:3 blended modified plastic, 30 parts by weight of epoxy resin E-44, and 0.5 parts by weight of polyamide 650.

[0088] Reflective layer raw materials: 15 parts by weight of quartz sand with a particle size of 0.1-0.3mm, 8 parts by weight of pearl powder with a particle size of 50-100μm, 22 parts by weight of glass microsphere powder with a particle size of 100-150μm, and 55 parts by weight of acrylic emulsion.

[0089] (2) Prepare reflective material and substrate raw materials; take materials and mix the above reflective layer raw materials to form reflective material for later use; take materials and mix the above substrate layer raw materials to obtain substrate material;

[0090] (3) Pressing and molding: Press the matrix material in the mold at 20MPa for 4min to obtain the matrix layer blank; coat the upper surface of the matrix layer blank with a reflective material of 0.8mm thickness, dehydrate at 80℃ for 3min, then cure at 110℃ for 6min, and finally cool to room temperature at 3℃ / min to obtain the finished energy-saving and noise-reducing composite material.

[0091] In this embodiment, the volume porosity of the energy-saving and noise-reducing composite material is 22%. The gradient through-holes with irregular pore sizes have a pore size of 0.3-0.5 mm on the surface of the reflective layer, a pore size of 0.6-0.8 mm in the middle of the composite material, and a pore size of 0.9-1.0 mm at the bottom of the composite material.

[0092] In this embodiment, the diffuse reflectivity of the reflective layer of the energy-saving and noise-reducing composite material is 88%.

[0093] The compressive strength of the energy-saving and noise-reducing composite material product in this embodiment is 28 MPa, and the flexural strength is 5.5 MPa.

[0094] In this embodiment, the noise reduction of the energy-saving and noise-reducing composite material product in the reverberation chamber with the test specimen is 18dB.

[0095] The energy-saving and noise-reducing composite material product of this embodiment was applied as an internal wall test case in a highway tunnel. The lighting energy consumption can be reduced by 35%; the initial noise of the highway tunnel internal wall before the finished product was assembled was 82dB, and the noise after assembly was 63dB.

[0096] Example 2

[0097] This embodiment provides a method for preparing an energy-saving and noise-reducing composite material, including the following steps:

[0098] (1) Raw material ratio:

[0099] Matrix layer raw materials: 25 parts by weight of quartz sand with a particle size of 1-3 mm, 10 parts by weight of calcium-based modified dolomite powder with a particle size of 1-3 mm, 10 parts by weight of metakaolin with a particle size of 1-3 mm, 10 parts by weight of wollastonite mineral fiber with a length of 2-4 mm, 10 parts by weight of recycled fiberglass granules with a particle size of 3-5 mm, 5 parts by weight of PP:PE=7:3 blended modified plastic, 29.7 parts by weight of epoxy resin E-44, and 0.3 parts by weight of polyamide 650.

[0100] Reflective layer raw materials: 10 parts by weight of quartz sand with a particle size of 0.1-0.3mm, 5 parts by weight of pearl powder with a particle size of 50-100μm, 20 parts by weight of glass microsphere powder with a particle size of 100-150μm, and 65 parts by weight of acrylic emulsion.

[0101] (2) Prepare reflective material and matrix raw materials; take materials and mix the above reflective layer raw materials to make reflective material for later use; take materials and mix the above matrix layer raw materials to obtain matrix material.

[0102] (3) Pressing and molding: Press the matrix material in the mold at 25MPa for 3min to obtain the matrix layer blank; coat the upper surface of the matrix layer blank with a reflective material of 0.5mm thickness, dehydrate at 90℃ for 3min, then cure at 120℃ for 5min, and finally cool to room temperature at 5℃ / min to obtain the finished energy-saving and noise-reducing composite material.

[0103] In this embodiment, the volume porosity of the energy-saving and noise-reducing composite material is 20%. The gradient through-holes with irregular pore sizes have a pore size of 0.2-0.4 mm on the surface of the reflective layer, a pore size of 0.5-0.7 mm in the middle of the composite material, and a pore size of 0.8-0.9 mm at the bottom of the composite material.

[0104] In this embodiment, the diffuse reflectivity of the reflective layer of the energy-saving and noise-reducing composite material is 85%.

[0105] The compressive strength of the energy-saving and noise-reducing composite material product in this embodiment is 30 MPa, and the flexural strength is 6.0 MPa.

[0106] In this embodiment, the noise reduction of the energy-saving and noise-reducing composite material product in the reverberation chamber with the test specimen is 15dB.

[0107] In this embodiment, the energy-saving and noise-reducing composite material was used as an interior wall test case in an underground utility tunnel. The results showed that lighting energy consumption could be reduced by 30%. The initial noise level in a highway tunnel before the finished product was assembled was 75 dB, and the noise level after assembly was 58 dB.

[0108] Example 3

[0109] This embodiment provides a method for preparing an energy-saving and noise-reducing composite material, including the following steps:

[0110] (1) Raw material ratio:

[0111] Matrix layer raw materials: 15 parts by weight of quartz sand with a particle size of 1-3 mm, 20 parts by weight of calcium-based modified dolomite powder with a particle size of 1-3 mm, 20 parts by weight of metakaolin with a particle size of 1-3 mm, 5 parts by weight of wollastonite mineral fiber with a length of 2-4 mm, 15 parts by weight of recycled fiberglass granules with a particle size of 3-5 mm, 10 parts by weight of PP:PE=7:3 blended modified plastic, 30 parts by weight of epoxy resin E-44, and 0.8 parts by weight of polyamide 650.

[0112] Reflective layer raw materials: 20 parts by weight of quartz sand with a particle size of 0.1-0.3mm, 10 parts by weight of pearl powder with a particle size of 50-100μm, 25 parts by weight of glass microsphere powder with a particle size of 100-150μm, and 45 parts by weight of acrylic emulsion.

[0113] (2) Prepare reflective material and matrix raw materials; take materials and mix the above reflective layer raw materials to make reflective material for later use; take materials and mix the above matrix layer raw materials to obtain matrix material.

[0114] (3) Pressing and molding: Press the matrix material in the mold at 15MPa for 5min to obtain the matrix layer blank; coat the upper surface of the matrix layer blank with a reflective material of 1.0mm thickness, dehydrate at 85℃ for 5min, then cure at 115℃ for 7min, and finally cool to room temperature at 2℃ / min to obtain the finished energy-saving and noise-reducing composite material.

[0115] In this embodiment, the volume porosity of the energy-saving and noise-reducing composite material is 25%. The gradient through-holes with irregular pore sizes have a pore size of 0.4-0.5 mm on the surface of the reflective layer, a pore size of 0.7-0.8 mm in the middle of the composite material, and a pore size of 0.9-1.0 mm at the bottom of the composite material.

[0116] In this embodiment, the diffuse reflectance of the reflective layer side of the energy-saving and noise-reducing composite material is 90%.

[0117] The compressive strength of the energy-saving and noise-reducing composite material product in this embodiment is 25 MPa, and the flexural strength is 5.0 MPa.

[0118] In this embodiment, the noise reduction of the energy-saving and noise-reducing composite material product in the reverberation chamber with the test specimen is 20dB.

[0119] The energy-saving and noise-reducing composite material product of this embodiment was piloted in the underground space of a cultural and tourism venue. The results showed that lighting energy consumption could be reduced by 40%, and the visual comfort score of tourists could be improved by 80%. The initial noise before the finished product was assembled was 70dB, and the noise after assembly was 48dB.

[0120] Comparative Example 1

[0121] The raw material ratios and preparation parameters of this comparative example are the same as those of Example 1, but the raw materials for the matrix layer, including quartz sand, calcium-modified dolomite powder, metakaolin, and recycled fiberglass granules, all have a particle size of 2-3 mm.

[0122] The porosity of the finished product in this comparative example is 15%, and the pores exist in a uniform form with a diameter of 0.5 to 0.6 mm.

[0123] The diffuse reflectance of the finished product in this comparative example is 87%.

[0124] The compressive strength of the finished product in this comparative example is 26 MPa.

[0125] The noise reduction of the comparative sample product in the reverberation chamber is 8 dB.

[0126] As can be seen from the finished product performance parameters of Comparative Example 1, although the matrix material uses aggregates with similar particle sizes, it can still achieve noise reduction, but the noise reduction effect is limited. This indicates that by compounding aggregates of different particle sizes, the irregularity of the pore size of the through-holes helps to achieve noise reduction. More importantly, this particle size distribution and the setting of different aggregates make the aggregates form gradient through-holes during the pressing and curing process. The existence of these gradient through-holes makes the amplitude of sound waves entering the gradient through-holes increase with the increase of pore size, thereby enabling the composite material to achieve a high noise attenuation effect as a whole, and thus achieve a noise attenuation of >15dB.

[0127] Comparative Example 2

[0128] The substrate material ratio in this comparative example is the same as that in Example 1. The preparation process omits the formation of the reflective layer, and other preparation parameters are the same as those in Example 1.

[0129] The bulk porosity of the product in this comparative example is 22%.

[0130] The diffuse reflectance of the upper surface of this comparative example product is 45%.

[0131] The noise reduction of the finished product in the comparative example chamber with reverberation was 17 dB.

[0132] The compressive strength of the finished product in this comparative example is 27 MPa.

[0133] As can be seen from the performance parameters of the comparative example product, when the substrate layer surface is not coated with reflective material to form a reflective layer, the diffuse reflectance of the resulting product is only 51% of that of Example 1, making it difficult to achieve the energy-saving target. At the same time, since the substrate layer contains irregularly sized through-holes that run from top to bottom through the substrate layer, the noise attenuation in the reverberation chamber with the specimen is only reduced by 1 dB compared to Example 1. This indicates that while the reflective layer achieves high diffuse reflectance, the pores of the reflective layer are interconnected with the pores of the substrate layer. This does not suppress the noise reduction of the irregular through-holes in the composite material, but rather helps to improve the noise reduction effect of the composite material.

Claims

1. An energy-saving and noise-reducing composite material, characterized in that, It includes a reflective layer (2) and a base layer (1) that are tightly bonded from top to bottom; The matrix layer (1) is formed by pressing and solidifying a matrix material, and irregular pores naturally form from top to bottom along the thickness direction of the matrix layer (1) during the forming process; the matrix material is composed of the following raw materials in parts by weight: 35-65 parts of aggregate with a particle size of 1-3mm; 10-15 parts of aggregate with a particle size of 3-5mm; 5-10 parts of wollastonite mineral fibers, 2-4 mm in length; 5-10 parts toughening agent; 30-40 parts adhesive; and, Hardener 0.3-0.8 parts; The reflective layer (2) is formed by coating a reflective material onto the surface of the substrate layer (1) and curing it, and during the forming process, reflective pores that penetrate the thickness direction of the reflective layer (2) are naturally formed; the reflective material is composed of the following raw materials in parts by weight: 10-20 parts of quartz sand with a particle size of 0.1-0.3 mm; 5-10 parts of pearlescent powder with a particle size of 50-100μm; 20-25 parts of glass microsphere powder with a particle size of 100-150 μm; and, 40-65 parts of acrylic emulsion; The irregular pores are interconnected with the pores of the reflective layer to form irregularly sized through holes (7); the pore diameter of the irregularly sized through holes (7) ranges from 0.2 mm to 1 mm; wherein, the irregularly sized through holes (7) include natural gradient through holes; the pore diameter of the natural gradient through holes gradually increases from pore diameter A (71) to pore diameter B (72) from top to bottom along the thickness direction of the energy-saving and noise-reducing composite material; wherein, pore diameter A (71) refers to the orifice diameter of the natural gradient through hole on the upper surface of the reflective layer (2), which is 0.2 to 0.5 mm; pore diameter B (72) refers to the orifice diameter of the natural gradient through hole on the lower surface of the substrate layer (1), which is 0.5 to 1 mm.

2. The energy-saving and noise-reducing composite material according to claim 1, characterized in that: The volume porosity of the energy-saving and noise-reducing composite material is 20-25%.

3. The energy-saving and noise-reducing composite material according to claim 1, characterized in that: The pressure for pressing and curing is 15-25 MPa.

4. The energy-saving and noise-reducing composite material according to claim 1, characterized in that: The aggregate with a particle size of 1-3 mm includes quartz sand with a particle size of 1-3 mm, natural modified mineral powder with a particle size of 1-3 mm, and inorganic non-metallic raw materials with a particle size of 1-3 mm; wherein, the weight ratio of quartz sand with a particle size of 1-3 mm, natural modified mineral powder with a particle size of 1-3 mm, and inorganic non-metallic raw materials with a particle size of 1-3 mm is (15-25):(10-20):(10-20).

5. The energy-saving and noise-reducing composite material according to claim 4, characterized in that: The quartz sand with a particle size of 1-3 mm contains SiO2 ≥ 98 wt% and mud ≤ 0.5 wt%; the natural modified mineral powder with a particle size of 1-3 mm is calcium-based modified dolomite powder, wherein CaCO3 and MgCO3 ≥ 95 wt%, and its modification is performed using zinc stearate, with the amount of zinc stearate being 1.5 wt%; the inorganic non-metallic raw material with a particle size of 1-3 mm is metakaolin, with SiO2 and Al2O3 ≥ 90 wt% and its loss on ignition ≤ 1.5 wt%.

6. The energy-saving and noise-reducing composite material according to claim 1, characterized in that: The 2-4 mm long wollastonite mineral fibers have a needle-like ratio ≥80% and a whiteness ≥90%; the 3-5 mm diameter aggregate is recycled fiberglass granules, composed of glass fiber and unsaturated polyester resin, with a glass fiber content of 30% and an unsaturated polyester resin purity ≥85%; the toughening agent is a modified plastic, which is a blend of PP and PE in a weight ratio of 7:3, with a melt index of 10-15 g / 10 min; the binder is an epoxy resin with an epoxy value of 0.41-0.47 eq / 100 g; the curing agent is polyamide 650, with an amine value of 200-240 mg KOH / g and a viscosity of 2000-4000 cP at 25℃; the 50-100 μm diameter pearlescent powder has a refractive index ≥1.9; and the 100-150 μm diameter glass microsphere powder has a light transmittance ≥92%.

7. The energy-saving and noise-reducing composite material according to claim 1, characterized in that: The acrylic emulsion has a solid content of ≥45% and a viscosity of 500-1000 cP.

8. A method for preparing the energy-saving and noise-reducing composite material according to any one of claims 1-7, characterized in that, Includes the following steps: a. The matrix material is mixed according to the weight proportions, and then pressed and cured to form the matrix layer; b. Take the reflective material according to the weight proportions, mix them, and coat them on the upper surface of the substrate layer in step a. After curing and molding, the energy-saving and noise-reducing composite material is obtained.

9. The application of the energy-saving and noise-reducing composite material according to any one of claims 1-7 in the preparation of a brightening and noise-reducing material for underground space walls.

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