Reflection type modified asphalt waterproof coiled material and preparation method thereof

Abstract

The invention provides a reflective modified asphalt waterproof coiled material and a preparation method thereof, and belongs to the technical field of waterproof coiled materials, the reflective modified asphalt waterproof coiled material is sequentially provided with a reflective composite surface membrane, a self-adhesion modified asphalt layer and an isolation bottom membrane from top to bottom, the reflective composite surface film comprises a polyvinylidene fluoride reflective weather-proof surface layer, a middle framework barrier layer and a metal barrier layer, and the metal barrier layer serves as a bottom layer and makes contact with the self-adhesion modified asphalt layer. The polyvinylidene fluoride reflective weather-resistant surface layer comprises a polyvinylidene fluoride base material, a titanium dioxide filler, a functional additive and an anti-aging agent; and the middle skeleton barrier layer is made of hollow microsphere modified polyethylene glycol terephthalate.

Description

Technical Field

[0001] This invention belongs to the field of waterproof membrane technology, and particularly relates to a reflective modified bitumen waterproof membrane and its preparation method. Background Technology

[0002] Reflective coatings or waterproof membranes for buildings are a new type of building material that relies on reflecting solar radiation to reduce roof and indoor temperatures in summer. Current research focuses primarily on high-reflectivity heat-insulating coatings, with insufficient research on reflective heat-insulating waterproof membranes. High-reflectivity waterproof membranes achieve their solar reflection performance through specular reflection or scattering generated by the material on the membrane surface. Currently, hot-melt modified bitumen membranes made of high-reflectivity ceramic particles are the main type, while surface-film-reinforced high-reflectivity, exposed modified bitumen waterproof membranes are rarely reported. The main reasons for this include: 1) Currently, exposed waterproof membranes are mainly butyl membranes or hot-melt modified bitumen membranes, and mature technology for exposed self-adhesive modified bitumen waterproof membranes has not yet been developed; 2) Self-adhesive modified bitumen waterproof membranes are difficult to match with high-reflectivity reinforcing films that can be exposed for extended periods. Summary of the Invention

[0003] In view of this, the present invention provides a reflective modified bitumen waterproof membrane and its preparation method, aiming to at least partially solve the above-mentioned technical problems. The technical solution provided by the present invention is as follows.

[0004] As one aspect of the present invention, a reflective modified bitumen waterproof membrane is provided, comprising, from top to bottom: a reflective composite membrane, a self-adhesive modified bitumen layer, and a separating base membrane. The reflective composite membrane includes a polyvinylidene fluoride (PVDF) reflective weather-resistant surface layer, an intermediate skeleton barrier layer, and a metal barrier layer, wherein the metal barrier layer serves as the bottom layer and is in contact with the self-adhesive modified bitumen layer. The PVDF reflective weather-resistant surface layer comprises PVDF vinyl material, titanium dioxide filler, functional additives, and anti-aging agents. The intermediate skeleton barrier layer is hollow microsphere-modified polyethylene terephthalate.

[0005] As another aspect of the present invention, a method for preparing a reflective modified bitumen waterproof membrane is provided, comprising: stacking and bonding a polyvinylidene fluoride reflective weather-resistant surface layer, an intermediate skeleton barrier layer, and a metal barrier layer in sequence, and curing them at 60-80°C for 120-170 hours to obtain a reflective composite membrane; flattening the reflective composite membrane, applying a self-adhesive modified bitumen layer to the surface of the metal barrier layer under rapid water cooling at 0-5°C, and after the self-adhesive modified bitumen layer cools down to 60-90°C, attaching an isolation base film, and then performing roller pressing and stress release treatment to prepare the reflective modified bitumen waterproof membrane.

[0006] Based on the above technical solution, the reflective modified bitumen waterproof membrane and its preparation method provided by the present invention have at least the following beneficial effects:

[0007] (1) In the product technical solution of the present invention, polyvinylidene fluoride (PVDF) is used as the substrate to reduce the refractive index of the substrate, and titanium dioxide (TiO2) with a higher refractive index is used as the filler to achieve the reflection of sunlight. The PVDF substrate and TiO2 filler are mixed and supplemented with functional additives and anti-aging agents. Due to the large difference in refractive index between PVDF and TiO2, the PVDF reflective weather-resistant surface layer formed has high reflectivity. Moreover, PVDF does not contain active groups such as ether bonds or carbonyl bonds, but has stable carbon-fluorine bonds, thus having good aging resistance and hydrophobicity, which can meet the requirements of long-term exposure of reflective waterproof membranes. Hollow microspheres have a certain strength and low thermal conductivity. They are used to modify polyethylene terephthalate (PET) and used as the intermediate skeleton to provide the strength required for waterproof membranes while effectively reducing the heat transfer from top to bottom. This allows sunlight to form a new scattering interface at the interface of the intermediate skeleton and dissipate in the form of radiative heat, which helps to improve the reflectivity of the reflective composite membrane. Using a metal barrier layer as the bottom layer of the reflective composite film further blocks and reflects sunlight, reducing or slowing down the aging rate of the self-adhesive modified asphalt layer. This invention stacks a PVDF reflective weather-resistant surface layer, a middle skeleton barrier layer, and a metal barrier layer from top to bottom, resulting in a reflective composite film with high reflectivity, weather resistance, and hydrophobicity. It can reflect over 95% of sunlight, reducing roof and indoor temperatures in summer and lowering air conditioning energy consumption.

[0008] (2) In the preparation method of the present invention, the preparation method of the reflective modified bitumen waterproof membrane of the present invention is relatively simple and can be prepared in batches. Attached Figure Description

[0009] Figure 1 This is a schematic diagram of the layered structure of the reflective modified bitumen waterproof membrane of the present invention;

[0010] Figure 2 This is a schematic diagram of the layered structure of the reflective composite mask of the present invention.

[0011] [Attached image labels]

[0012] 1-Isolation base film, 2-Self-adhesive modified asphalt layer, 3-Reflective composite surface film, 4-Isolation side film, 301-Metal barrier layer, 302-Intermediate skeleton barrier layer, 303-Polyvinylidene fluoride reflective weather-resistant surface layer. Detailed Implementation

[0013] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. However, it should be understood that these descriptions are exemplary only and are not intended to limit the scope of the invention. In the following detailed description, numerous specific details are set forth to provide a thorough understanding of the embodiments of the invention for ease of explanation. However, it will be apparent that one or more embodiments may be practiced without these specific details. Furthermore, descriptions of well-known structures and techniques are omitted in the following description to avoid unnecessarily obscuring the concept of the invention.

[0014] Reflective coatings or waterproof membranes reduce roof and indoor temperatures by reflecting solar radiation. Reflective thermal insulation technology mainly includes three types: reflection, blocking, and radiation. Reflective thermal insulation materials often combine these three technologies to achieve a cooling effect. GB / T 25261-2018 "Building Reflective Thermal Insulation Coatings" and JG / T 235-2014 "Building Reflective Thermal Insulation Coatings" indicate that the characterization of reflective performance is mainly based on solar reflectance and near-infrared reflectance. These two types of light include visible light and infrared light, with wavelengths between 300nm and 2500nm. Improving the reflectivity of materials mainly requires addressing the reflection of visible and infrared light, which can achieve at least 92% energy savings (these two types account for the total solar energy). Solar reflection technology mainly relies on the high specular reflection and scattering of sunlight by the film-forming material, as well as low absorption and transmission. Since the existing building maintenance structure base layer is mostly made of opaque materials, the main means to improve reflectivity is to increase reflectivity while reducing absorption. Reflectivity is the interfacial reflection or diffraction of light between two media due to the difference in refractive index, and its magnitude is related to the difference in refractive index. High-reflectivity materials generally require a substrate with a lower refractive index and fillers with higher reflectivity, supplemented by additives and dispersion media. Among them, titanium dioxide (TiO2), especially rutile TiO2, is currently the best choice among fillers for improving reflectivity due to its high refractive index of 2.73. However, it only has high reflectivity for visible and near-infrared light, while its reflectivity for ultraviolet light is low. This results in ultraviolet light transmitted through the substrate having a significant impact on the aging of the underlying self-adhesive modified asphalt layer.

[0015] Current reflective waterproof membranes are mainly made of butyl materials and hot-melt modified bitumen membranes. In order to improve their reflectivity, it has been proposed to add reflective powder, nano silica, zinc oxide, aluminum oxide and other materials for blending. However, the cost is high and the process is complicated. The weather resistance and applicability of the membranes made from these materials have not yet been proven.

[0016] Therefore, in order to achieve high reflectivity of self-adhesive modified bitumen waterproof membrane, it is currently necessary not only to solve the problem of high reflectivity of the membrane, but also to ensure the weather resistance of the membrane and its compatibility with self-adhesive modified bitumen.

[0017] In response, this invention addresses this issue based on the principle of light scattering: the greater the difference in refractive index between the filler and the substrate, the greater the degree of scattering. Since rutile TiO2 has the highest refractive index (2.73) among the fillers, this invention considers the refractive index of the substrate and achieves a greater difference between the two by further reducing the refractive index of the substrate, thus giving the film high reflectivity. During implementation, it was found that fluorocarbon resins, especially pure polyvinylidene fluoride (PVDF) films, have a refractive index between 1.42 and 1.50 and possess excellent aging resistance and hydrophobic properties, making them suitable for manufacturing high-reflectivity, weather-resistant PVDF surface layers.

[0018] Furthermore, while ensuring that the surface layer has high reflectivity, weather resistance and hydrophobic properties, the present invention improves the intermediate layer by using hollow microspheres to modify polyethylene terephthalate (PET) to block heat transfer and provide the strength required for waterproof membranes, while improving the reflectivity of the reflective composite film.

[0019] Specifically, the reflective modified bitumen waterproof membrane provided by the present invention comprises, from top to bottom: a reflective composite membrane, a self-adhesive modified bitumen layer, and an isolation base membrane. The reflective composite membrane includes a polyvinylidene fluoride (PVDF) reflective weather-resistant surface layer, an intermediate skeleton barrier layer, and a metal barrier layer. The metal barrier layer serves as the bottom layer and is in contact with the self-adhesive modified bitumen layer. The PVDF reflective weather-resistant surface layer contains PVDF vinyl material, titanium dioxide filler, functional additives, and anti-aging agents. The intermediate skeleton barrier layer is hollow microsphere-modified polyethylene terephthalate.

[0020] In embodiments of this invention, polyvinylidene fluoride (PVDF), with its low refractive index, excellent weather resistance, and hydrophobicity, is used as the substrate with a low refractive index in high-reflectivity materials. Meanwhile, titanium dioxide (TiO2), with a higher refractive index, is used as a filler to achieve high solar reflectivity. Mixing the PVDF substrate and TiO2 filler, along with functional additives and anti-aging agents, results in a PVDF reflective weather-resistant surface layer with high reflectivity, good aging resistance, and hydrophobicity, potentially meeting the requirements for long-term exposure of reflective waterproof membranes. Utilizing the strength and low thermal conductivity of hollow microspheres, polyethylene terephthalate (PET) is modified. The modified material serves as the intermediate skeleton, providing the required strength for the waterproof membrane while effectively reducing heat transfer from top to bottom. It also allows sunlight to form a new scattering interface at the intermediate skeleton, dissipating as radiative heat, thus improving the reflectivity of the reflective composite film. By using a metal barrier layer as the bottom layer of the reflective composite membrane, its opaque nature further blocks and reflects sunlight, reducing or slowing down the aging rate of the self-adhesive modified bitumen layer caused by sunlight. Thus, this invention provides a reflective composite membrane formed by the sequential stacking of a PVDF reflective weather-resistant surface layer, an intermediate skeleton barrier layer, and a metal barrier layer. This membrane offers excellent reflective and heat-insulating properties, achieving a solar reflectance ≥0.95 and a heat radiation ratio ≥0.94. Compared to ordinary modified bitumen waterproof membranes, its surface temperature in summer is 15-20°C lower (at an ambient temperature of 35°C), effectively reducing roof and indoor temperatures in summer and lowering air conditioning energy consumption.

[0021] Figure 1 This is a schematic diagram of the layered structure of the reflective modified bitumen waterproof membrane of the present invention. Figure 2 This is a schematic diagram of the layered structure of the reflective composite mask of the present invention.

[0022] like Figures 1-2As shown, the reflective modified bitumen waterproof membrane of the present invention comprises, from top to bottom: a reflective composite membrane 3, a self-adhesive modified bitumen layer 2, and a separating base membrane 1. The reflective composite membrane 3 comprises, from top to bottom: a polyvinylidene fluoride reflective weather-resistant surface layer 303, a middle skeleton barrier layer 302, and a metal barrier layer 301. Further, in the reflective modified bitumen waterproof membrane, the width of both sides of the separating base membrane 1 is 30-50 mm wider than the width of the self-adhesive modified bitumen layer 2, for example, it can be 30 mm, 35 mm, 40 mm, 45 mm, 50 mm, or any value within this range, to facilitate quick removal during construction. The separating base membrane is a silicone oil-coated separating membrane. The membrane material can be selected from any one of polypropylene (PP), polyethylene terephthalate (PET), and polyethylene (PE). The thickness of the separating base membrane is 20-40 μm to prevent the self-adhesive modified bitumen layer from sticking during the roll-up process and from damage during transportation. One side of the self-adhesive modified bitumen layer 2 is aligned with one side of the reflective composite membrane 3, while the other side of the self-adhesive modified bitumen layer 2 is 8-12mm wider than the reflective composite membrane 3 to serve as an overlap edge. For example, the overlap edge can be 8mm, 9mm, 10mm, 11mm, 12mm, or any value within this range to achieve overlap between the two waterproof membranes. Additionally, the surface of the overlap edge is covered with a release liner 4, which is wider than the overlap edge. This release liner 4 protects the uncovered self-adhesive modified bitumen layer, preventing adhesion and damage. During construction, the release liner 4 can be removed for use. The material of the release liner 4 can be the same as that of the release base membrane, both being silicone oil-coated release films. The film material can also be selected from PP, PET, and PE, and the thickness of the release liner 4 can be the same as that of the release base membrane 1. The thickness of the self-adhesive modified bitumen layer is 1.5-2.0 mm to achieve adhesion with the substrate, which can be cement, insulation board, metal plate, etc. The self-adhesive modified bitumen layer used in this invention is coated with ordinary self-adhesive modified bitumen, and its performance meets the requirements of GB 23441-2009 "Requirements for Polymer Modified Bitumen Waterproof Membranes".

[0023] According to embodiments of the present invention, the initial and aging values ​​of the tensile strength and elongation at break of the polyvinylidene fluoride (PVDF) reflective weather-resistant surface layer all improve with increasing thickness. Specifically, when the thickness is ≤15μm, the performance decreases significantly with decreasing thickness. When the thickness is between 22.5 and 30μm, the performance improvement is relatively slow. Therefore, the thickness of the PVDF reflective weather-resistant surface layer of the present invention is 20-30μm, for example, 20μm, 25μm, 30μm, etc., or any value within this range. The thickness of the intermediate skeleton barrier layer is 75-125μm, for example, 75μm, 80μm, 85μm, 90μm, 100μm, 110μm, 115μm, 120μm, 125μm, etc., or any value within this range. Within this range, cost, strength, and thermal insulation effect can be balanced. The thickness of the bottom metal barrier layer is 6-20 μm, for example, it can be 6 μm, 8 μm, 10 μm, 12 μm, 15 μm, 18 μm, 20 μm, etc., or any value within this range. Within this range, the metal is relatively thin and flexible, avoiding cracking and increased costs during use, while achieving good light blocking and improved reflection effects. The metal light-blocking layer used in this invention can be aluminum foil, preferably O-state aluminum foil, which can block 99.99% of sunlight, reduce the aging effect of ultraviolet rays on the underlying modified asphalt, and its performance meets the high-precision requirements of GBT3198-2010 "Aluminum and Aluminum Alloy Foil".

[0024] According to embodiments of the present invention, the polyvinylidene fluoride (PVDF) reflective weather-resistant surface layer of the present invention is formed by extrusion granulation and casting of polyvinylidene fluoride resin, titanium dioxide filler, functional additives, and anti-aging agents. Specifically, by weight, the polyvinylidene fluoride reflective weather-resistant surface layer comprises: 60-80 parts of polyvinylidene fluoride resin, 5-25 parts of copolymer of polyvinylidene fluoride with tetrafluoroethylene or hexafluoropropylene, 10-20 parts of titanium dioxide filler, 3-5 parts of functional additives, and 0.5-1.0 parts of anti-aging agent.

[0025] In the embodiments of this invention, the refractive index of pure PVDF film is between 1.42 and 1.50, which is already among the lowest refractive index films of various plastics. Modification is expected to further reduce the refractive index of PVDF and improve the reflective performance of the PVDF reflective weather-resistant surface layer. Polyethylene (PE), polypropylene (PP), polyurethane (PU), polymethyl methacrylate (PMMA), and acrylonitrile-butadiene-styrene (ABS) all have higher refractive indices than PVDF and contain active groups such as ether bonds (-COC) and carbonyl groups (-C=O), which reduce the aging resistance of the materials and make them unsuitable as choices for modified PVDF. During implementation, it was found that the refractive index of tetrafluoroethylene-vinylidene fluoride (TFE-VDF) copolymer is 1.40, melting point is 155-160℃, decomposition temperature is >360℃, and operating temperature is -60~125℃; the refractive index of vinylidene fluoride-hexafluoropropylene (VDF-HFP) copolymer is 1.42, melting point is 150~180℃, decomposition temperature is >380℃, and operating temperature is -40~150℃; and the refractive index of PVDF is 1.42-1.5, melting point is 150~180℃, decomposition temperature is >310℃, and operating temperature is -40~150℃. All three have similar properties, exhibiting good hydrophobicity and aging resistance. Furthermore, the refractive indices of tetrafluoroethylene (TFE) and hexafluoropropylene (HFP) are lower than those of PVDF, suggesting the potential to reduce the weather resistance of the substrate through blending modification of PVDF with TFE-VDF copolymers or VDF-HFP copolymers.

[0026] Furthermore, considering that rutile TiO2 has the highest refractive index and high reflectivity for visible and infrared light, but low reflectivity for ultraviolet light; while anatase TiO2 has a refractive index of 2.55, its reflectivity for visible and infrared light is slightly lower than that of rutile TiO2, but it has high reflectivity for ultraviolet light. Combining the two is expected to improve the high reflectivity of sunlight through a compounding method. Therefore, the titanium dioxide of this invention comprises rutile TiO2 and anatase TiO2, with a compounding ratio of 4:1 to 1:4, for example, 4:1, 4:2, 4:3, 4:4, 3:1, 2:1, 1:1, 2:2, 1:2, 1:3, 1:4, etc. For example, 10-20 parts of TiO2 may include 8-15 parts of rutile TiO2 and 2-5 parts of anatase TiO2. The rutile phase TiO2 and anatase phase TiO2 used have a particle size of 200-500nm to ensure uniform dispersion.

[0027] Furthermore, the titanium dioxide used in this invention is sodium silicate and aluminum sulfate modified titanium dioxide. Specifically, obtaining sodium silicate and aluminum sulfate modified titanium dioxide includes: heating a titanium dioxide slurry of 20%-40% by mass to 60-80℃ and stirring at 500-1000 r / min for 10-30 min; adding a sodium silicate solution (based on SiO2 mass fraction of 6% of titanium dioxide) and adjusting the pH to 8-9, then aging for 1-2 h; cooling to 50-70℃, adding aluminum sulfate (based on Al2O3 mass fraction of 4% of titanium dioxide) at 200-400 r / min, adjusting the pH to 7-8, and continuing aging for 2-4 h; after washing and filtration, sodium silicate and aluminum sulfate modified titanium dioxide is obtained, wherein the modified titanium dioxide includes: modified rutile phase TiO2 and modified anatase phase TiO2. By coating and modifying TiO2, its reactivity can be reduced, the risk of precipitation and pulverization after ultraviolet irradiation can be decreased, and its outdoor durability can be improved.

[0028] According to embodiments of the present invention, the functional additive is acrylic resin or epoxy resin. The anti-aging agent includes an anti-UV aging agent and an anti-thermal-oxidative aging agent, totaling 0.5-1.0 parts, which can ensure its own optical and thermal stability while reducing the aging of the self-adhesive modified bitumen layer by ultraviolet radiation. The presence of the functional additive can improve the tensile elongation of PVDF and enhance its flowability during extrusion processing; it also reduces the crystallinity of PVDF and lowers its refractive index. However, since its weather resistance is inferior to that of PVDF, the amount added needs to be controlled; excessive addition will affect the weather resistance of the waterproof membrane.

[0029] According to an embodiment of the present invention, the intermediate framework barrier layer is formed by extrusion granulation and casting of polyethylene terephthalate (PET), hollow microspheres, anatase titanium dioxide, and an anti-aging agent. Specifically, by weight, the intermediate framework barrier layer comprises: 90-95 parts polyethylene terephthalate, 3-5 parts hollow microspheres, 2-3 parts anatase titanium dioxide, and 0.5-1.0 parts anti-aging agent. The anti-aging agent includes an anti-UV aging agent and an anti-thermal-oxidative aging agent; the hollow microspheres are selected from any one of hollow glass microspheres, hollow ceramics, and hollow resins, preferably hollow glass microspheres, which contain an inert gas or air, the inert gas being nitrogen; the particle size of the hollow microspheres is 10-20 μm; the particle size of the anatase titanium dioxide is 200-500 nm. By mixing hollow microspheres, anatase TiO2, and anti-aging agents, and modifying PET, the resulting intermediate framework barrier layer combines strength and a skeletal structure. The tightly packed hollow microspheres reduce the thermal conductivity of the intermediate framework barrier layer, decreasing downward heat conduction and allowing sunlight and heat to dissipate as radiative heat, thus increasing reflectivity. The anatase TiO2 within the intermediate framework barrier layer further reflects ultraviolet light, while the anti-aging agent ensures its thermal and optical stability.

[0030] As a second aspect of the present invention, a method for preparing a reflective modified bitumen waterproof membrane is provided, comprising: steps A1-A2.

[0031] Step A1: Stack and glue the polyvinylidene fluoride reflective weather-resistant surface layer, the intermediate skeleton barrier layer, and the metal barrier layer in sequence, and cure them at 60-80℃ for 120-170h to obtain the reflective composite mask.

[0032] Step A2: Flatten the reflective composite film, apply a self-adhesive modified bitumen layer to the metal barrier layer under rapid water cooling at 0-5℃, and after the self-adhesive modified bitumen layer cools down to 60-90℃, apply the isolation base film, and after roller pressing and stress release treatment, the reflective modified bitumen waterproof membrane is prepared.

[0033] In the embodiments of the present invention, the preparation method of the reflective modified bitumen waterproof membrane of the present invention is relatively simple, suitable for mass production, and does not use harmful solvents, making it more environmentally friendly and producing less waste liquid.

[0034] According to an embodiment of the present invention, in step A1, the polyvinylidene fluoride (PVDF) reflective weather-resistant surface layer is obtained through the following steps: PVDF resin, PVDF copolymer with tetrafluoroethylene or hexafluoropropylene copolymer, titanium dioxide filler, functional additives, and anti-aging agent from the above formulation are added to a hopper. After uniform mixing, the mixture is conveyed to a twin-screw extruder at 180-220°C for melting and thorough mixing, followed by extrusion and granulation into white masterbatch with a diameter of 4-6 mm. Further, the white masterbatch is conveyed to a single-screw extruder and extruded at 200-220°C to form a 20-30 μm thick PVDF reflective weather-resistant surface layer via casting.

[0035] According to an embodiment of the present invention, in step A1, the intermediate skeleton barrier layer is obtained by the following steps: polyethylene terephthalate (PET), hollow microspheres, anatase titanium dioxide and anti-aging agent in the above formula are mixed evenly at a speed of 100-300 r / min, and then conveyed to a single screw extruder at 250-275°C for melting (the screw speed control unit exceeds 200 r / min), extruded, and cast to form an intermediate skeleton barrier layer with a thickness of 75-125 μm.

[0036] According to an embodiment of the present invention, in step A1, polyurethane adhesive is used for bonding, and the amount of polyurethane adhesive used is 5-10 g / m³. 2 (Dry adhesive amount); The thickness of the self-adhesive modified asphalt layer is 1.5-2.0mm.

[0037] The technical solution of the present invention will be described in detail below with reference to specific embodiments and comparative examples.

[0038] Example 1

[0039] Reflective modified bitumen waterproof membrane: This membrane consists of a reflective composite membrane, a 1.5mm thick self-adhesive modified bitumen layer, and a silicone-coated base membrane. The reflective composite membrane comprises a 25μm thick polyvinylidene fluoride reflective weather-resistant surface layer, a 100μm thick intermediate skeleton barrier layer, and a 10μm thick aluminum foil, bonded together from top to bottom with weather-resistant polyurethane adhesive. The dry adhesive usage is 8g / m². 2 The reflective composite mask comprises: 65 parts PVDF resin, 15 parts tetrafluoroethylene-vinylidene fluoride (TFE-VDF) copolymer, 15 parts modified TiO2 (rutile TiO2: anatase TiO2 = 4:1), 4 parts PMMA resin, and 1 part anti-aging agent (UV anti-aging agent: thermo-oxidative anti-aging agent = 2:1); the intermediate skeleton barrier layer (PET layer) comprises: 92 parts PET masterbatch, 5 parts hollow glass microspheres with a particle size of 15μm, 2 parts unmodified anatase TiO2 (particle size of 200-500nm), 0.5 parts UV anti-aging agent, and 0.5 parts thermo-oxidative anti-aging agent.

[0040] The preparation method of the reflective composite mask includes: taking 65 parts of PVDF resin, 15 parts of tetrafluoroethylene-vinylidene fluoride (TFE-VDF) copolymer, 15 parts of modified TiO2 (rutile phase TiO2: anatase phase TiO2 = 4:1), 4 parts of PMMA resin, and 1 part of anti-aging agent (anti-UV aging agent: anti-thermal oxidation aging agent = 2:1) and adding them sequentially into a hopper. After preliminary mixing, the above materials are fed into a twin-screw extruder heated to 180~220℃. After thorough mixing, the mixture is granulated into white masterbatch with a diameter of 4-6mm. The masterbatch is then placed in a single-screw extruder and extruded at a high temperature of 200~220℃ and cast to produce a 25μm high-reflective composite mask.

[0041] The preparation process of modified TiO2 is as follows: a 30% (w / w) compound TiO2 slurry is prepared using deionized water, heated to 70℃, and rapidly stirred at 1000 r / min for 20 min. Sodium silicate solution (based on SiO2 mass fraction equal to 6% of titanium dioxide) is added at this temperature and stirring speed. Dilute sulfuric acid is slowly added dropwise to adjust the pH to 8. After stirring for 5-10 min, stirring is stopped, and the mixture is aged for 2 h. The temperature is lowered to 50-70℃, stirring is started at 200 r / min, aluminum sulfate (based on Al2O3 mass fraction equal to 4% of titanium dioxide) is slowly added, and sodium hydroxide is slowly added dropwise to adjust the pH to 8. Stirring is stopped, and the mixture is aged for 3 h. The mixture is filtered and washed to obtain a filter cake. The filter cake is dried in an oven at 105℃ to obtain the modified product. The modified product is then ground, dispersed, and filtered to obtain modified TiO2.

[0042] Preparation method of the intermediate skeleton barrier layer: 92 parts of PET masterbatch, 5 parts of hollow glass microspheres with a particle size of 15 μm, 2 parts of unmodified anatase TiO2 (particle size of 200-500 nm), 0.5 parts of anti-UV anti-aging agent and 0.5 parts of anti-thermal-oxidative aging agent are added sequentially to a mixing tank and mixed at low speed (150 r / min) for 20 min. The above mixture is fed into a single-screw extruder at 250~275℃, the screw speed is controlled not to exceed 200 r / min, and a 100 μm PET film product is obtained by extrusion casting at this temperature.

[0043] Example 2

[0044] The same preparation process as in Example 1 was used, except that the composition of the fluorocarbon resin in the reflective composite film was different. Specifically, the reflective composite film included: 65 parts PVDF resin, 15 parts vinylidene fluoride-hexafluoropropylene (VDF-HFP) copolymer, 15 parts modified TiO2 (rutile phase TiO2: anatase phase TiO2 = 4:1), 4 parts PMMA resin, and 1 part anti-aging agent (anti-UV aging agent: anti-thermal oxidation aging agent = 2:1).

[0045] Comparative Example 1

[0046] The same preparation process as in Example 1 was used, except that fluorocarbon resin was not included. Specifically, the reflective composite film includes: 80 parts PVDF resin, 15 parts modified TiO2 (rutile TiO2: anatase TiO2 = 4:1), 4 parts PMMA resin, and 1 part anti-aging agent (anti-UV aging agent: anti-thermal-oxidative aging agent = 2:1).

[0047] The performance of the reflective modified bitumen waterproof membranes of Examples 1-2 and Comparative Example 1 was tested, and the specific test results are shown in Table 1.

[0048] Table 1

[0049]

[0050] As shown in Table 1, blending PVDF with VDF-HFP copolymer or TFE-VDF copolymer can effectively improve the reflectivity of reflective composite membranes, thereby improving the reflectivity of reflective modified bitumen waterproof membranes. Among these, the blending modification of TFE-VDF copolymer with PVDF has the most significant effect on improving reflectivity.

[0051] Example 3

[0052] The same preparation process as in Example 1 was used, except that the composition and amount of the reflective composite mask were different. Specifically, the reflective composite mask included: 60 parts PVDF resin, 20 parts tetrafluoroethylene-vinylidene fluoride (TFE-VDF) copolymer, 15 parts modified TiO2 (rutile TiO2: anatase TiO2 = 4:1), 4 parts PMMA resin, and 1 part anti-aging agent (anti-UV aging agent: anti-thermal-oxidative aging agent = 2:1).

[0053] Example 4

[0054] The same preparation process as in Example 1 was used, except that the composition and amount of the reflective composite mask were different. Specifically, the reflective composite mask included: 70 parts PVDF resin, 10 parts tetrafluoroethylene-vinylidene fluoride (TFE-VDF) copolymer, 15 parts modified TiO2 (rutile phase TiO2: anatase phase TiO2 = 4:1), 4 parts PMMA resin, and 1 part anti-aging agent (anti-UV aging agent: anti-thermal oxidation aging agent = 2:1).

[0055] Example 5

[0056] The same preparation process as in Example 1 was used, except that the composition and amount of the reflective composite mask were different. Specifically, the reflective composite mask included: 75 parts PVDF resin, 5 parts tetrafluoroethylene-vinylidene fluoride (TFE-VDF) copolymer, 15 parts modified TiO2 (rutile phase TiO2: anatase phase TiO2 = 4:1), 4 parts PMMA resin, and 1 part anti-aging agent (anti-UV aging agent: anti-thermal-oxidative aging agent = 2:1).

[0057] The performance of the reflective modified bitumen waterproof membranes of Examples 3-5 above was tested, and the specific test results are shown in Table 2.

[0058] Table 2

[0059]

[0060] As shown in Table 2, within the range of reflective composite film formulations provided by the present invention, all formulations can improve the solar reflectance and near-infrared reflectance of waterproof membranes. Among them, the formulation in Example 1 has the best effect.

[0061] Comparative Example 2

[0062] The same preparation process as in Example 1 was used, except that unmodified TiO2 was used. Specifically, the reflective composite film comprises: 65 parts PVDF resin, 15 parts tetrafluoroethylene-vinylidene fluoride (TFE-VDF) copolymer, 15 parts unmodified TiO2 (rutile phase TiO2: anatase phase TiO2 = 4:1), 4 parts PMMA resin, and 1 part anti-aging agent (anti-UV aging agent: anti-thermal oxidation aging agent = 2:1).

[0063] The performance of the reflective modified bitumen waterproof membranes of Example 1 and Comparative Example 2 was tested, and the specific test results are shown in Table 3.

[0064] Table 3

[0065]

[0066] As shown in Table 3, the reflective composite film formed by unmodified TiO2 initially has a high solar reflectance, near-infrared reflectance, and initial hemispherical reflectance. However, after long-term aging tests, its solar reflectance decreases, indicating that the unmodified TiO2 reflective composite film is not suitable for long-term use and cannot solve the problems of long-term exposure and weather resistance of waterproof membranes.

[0067] Example 6

[0068] The same preparation process as in Example 1 was used, except that the composition and amount of the reflective composite mask were different. Specifically, the reflective composite mask included: 69 parts PVDF resin, 16 parts tetrafluoroethylene-vinylidene fluoride (TFE-VDF) copolymer, 10 parts modified TiO2 (rutile TiO2: anatase TiO2 = 4:1), 4 parts PMMA resin, and 1 part anti-aging agent (anti-UV aging agent: anti-thermal-oxidative aging agent = 2:1).

[0069] Example 7

[0070] The same preparation process as in Example 1 was used, except that the composition and amount of the reflective composite mask were different. Specifically, the reflective composite mask included: 61 parts PVDF resin, 14 parts tetrafluoroethylene-vinylidene fluoride (TFE-VDF) copolymer, 20 parts modified TiO2 (rutile TiO2: anatase TiO2 = 4:1), 4 parts PMMA resin, and 1 part anti-aging agent (anti-UV aging agent: anti-thermal-oxidative aging agent = 2:1).

[0071] The performance of the reflective modified bitumen waterproof membranes of Examples 1, 6-7 above was tested, and the specific test results are shown in Table 4.

[0072] Table 4

[0073]

[0074] As shown in Table 4, the difference between Examples 1, 6, and 7 lies in the proportion of modified TiO2 added. The greater the amount of modified TiO2 added, the lower the film elongation. When the elongation is too low, it is not conducive to film formation and processing.

[0075] Example 8

[0076] The same preparation process as in Example 1 was used, except that the ratio of rutile TiO2 to anatase TiO2 was different. Specifically, the reflective composite film includes: 65 parts PVDF resin, 15 parts tetrafluoroethylene-vinylidene fluoride (TFE-VDF) copolymer, 15 parts modified TiO2 (rutile TiO2: anatase TiO2 = 4:0), 4 parts PMMA resin, and 1 part anti-aging agent (anti-UV aging agent: anti-thermal-oxidative aging agent = 2:1).

[0077] Example 9

[0078] The same preparation process as in Example 1 was used, except that the ratio of rutile TiO2 to anatase TiO2 was different. Specifically, the reflective composite film includes: 65 parts PVDF resin, 15 parts tetrafluoroethylene-vinylidene fluoride (TFE-VDF) copolymer, 15 parts modified TiO2 (rutile TiO2: anatase TiO2 = 3:1), 4 parts PMMA resin, and 1 part anti-aging agent (anti-UV aging agent: anti-thermal-oxidative aging agent = 2:1).

[0079] Example 10

[0080] The same preparation process as in Example 1 was used, except that the ratio of rutile TiO2 to anatase TiO2 was different. Specifically, the reflective composite film includes: 65 parts PVDF resin, 15 parts tetrafluoroethylene-vinylidene fluoride (TFE-VDF) copolymer, 15 parts modified TiO2 (rutile TiO2: anatase TiO2 = 2:2), 4 parts PMMA resin, and 1 part anti-aging agent (anti-UV aging agent: anti-thermal-oxidative aging agent = 2:1).

[0081] Example 11

[0082] The same preparation process as in Example 1 was used, except that the ratio of rutile TiO2 to anatase TiO2 was different. Specifically, the reflective composite film includes: 65 parts PVDF resin, 15 parts tetrafluoroethylene-vinylidene fluoride (TFE-VDF) copolymer, 15 parts modified TiO2 (rutile TiO2: anatase TiO2 = 1:3), 4 parts PMMA resin, and 1 part anti-aging agent (anti-UV aging agent: anti-thermal-oxidative aging agent = 2:1).

[0083] Example 12

[0084] The same preparation process as in Example 1 was used, except that the ratio of rutile TiO2 to anatase TiO2 was different. Specifically, the reflective composite film includes: 65 parts PVDF resin, 15 parts tetrafluoroethylene-vinylidene fluoride (TFE-VDF) copolymer, 15 parts modified TiO2 (rutile TiO2: anatase TiO2 = 0:4), 4 parts PMMA resin, and 1 part anti-aging agent (anti-UV aging agent: anti-thermal-oxidative aging agent = 2:1).

[0085] The performance of the reflective modified bitumen waterproof membranes of Examples 1, 8-12 above was tested, and the specific test results are shown in Table 5.

[0086] Table 5

[0087]

[0088] Table 5 shows that increasing the proportion of anatase TiO2 in modified TiO2 will reduce the solar reflectance and near-infrared reflectance of the waterproof membrane. Similarly, increasing the proportion of rutile TiO2 will increase the visible light reflectance and near-infrared reflectance of the waterproof membrane, but rutile TiO2 alone cannot further improve the solar reflectance. By combining rutile TiO2 and anatase TiO2, the overall solar reflectance can be improved.

[0089] Comparative Example 3

[0090] The same preparation process as in Example 1 was used, except for the composition of the intermediate framework barrier layer. Specifically, the intermediate framework barrier layer includes: 97 parts PET masterbatch, 0 parts hollow glass microspheres with a particle size of 15 μm, 2 parts unmodified anatase TiO2 (particle size of 200-500 nm), 0.5 parts UV aging agent, and 0.5 parts thermo-oxidative aging agent.

[0091] Example 13

[0092] The same preparation process as in Example 1 was used, except for the composition of the intermediate framework barrier layer. Specifically, the intermediate framework barrier layer includes: 96 parts PET masterbatch, 1 part hollow glass microspheres with a particle size of 15 μm, 2 parts unmodified anatase TiO2 (particle size of 200-500 nm), 0.5 parts UV aging resistant agent, and 0.5 parts thermo-oxidative aging resistant agent.

[0093] Example 14

[0094] The same preparation process as in Example 1 was used, except for the composition of the intermediate framework barrier layer. Specifically, the intermediate framework barrier layer includes: 94 parts PET masterbatch, 3 parts hollow glass microspheres with a particle size of 15 μm, 2 parts unmodified anatase TiO2 (particle size of 200-500 nm), 0.5 parts UV aging agent and 0.5 parts thermo-oxidative aging agent.

[0095] The performance of the reflective modified bitumen waterproof membranes of Example 1, Comparative Example 3, and Examples 13-14 were tested, and the specific test results are shown in Table 6.

[0096] Table 6

[0097]

[0098] As shown in Table 6, although hollow glass microspheres have a heat insulation function, they have little effect on reflectivity, but they have a good effect on heat emission. With the increase of the amount added, the hemispherical emissivity increases, but excessive addition will increase the melt viscosity, increase the difficulty of film formation, and if the addition is too large, it will be detrimental to the continuity of the film structure after the hollow glass microspheres are continuous.

[0099] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above descriptions are merely specific embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A reflective modified bituminous waterproofing membrane, characterized in that, From top to bottom are sequentially arranged: a reflective composite surface film, a self-adhesive modified asphalt layer and a release bottom film, the reflective composite surface film comprises a polyvinylidene fluoride reflective weatherable surface layer, an intermediate skeleton barrier layer, and a metal barrier layer, wherein the metal barrier layer as the bottom layer is in contact with the self-adhesive modified asphalt layer; The polyvinylidene fluoride reflective weatherable surface layer comprises a polyvinylidene fluoride base material, a titanium dioxide filler, a functional additive and an anti-aging agent. The intermediate skeleton barrier layer is a hollow microsphere modified polyethylene terephthalate.

2. The reflective modified asphalt waterproof roll material according to claim 1, characterized in that: In the reflective modified asphalt waterproof roll material, the width of the release bottom film on both sides is 30-50mm wider than the width of the self-adhesive modified asphalt layer, the width of one side of the self-adhesive modified asphalt layer is 8-12mm wider than the reflective composite surface film as the lap edge, the surface of the lap edge is covered with a release edge film, and the release edge film is wider than the lap edge.

3. The reflective modified asphalt waterproof roll material according to claim 2, characterized in that: The thickness of the polyvinylidene fluoride reflective weatherable surface layer is 20-30μm; The thickness of the intermediate skeleton barrier layer is 75-125μm; The thickness of the metal barrier layer is 6-20μm, and the metal barrier layer is a metal aluminum foil; The thickness of the self-adhesive modified asphalt layer is 1.5-2.0mm; The release bottom film and the release edge film are both release films coated with silicone oil, and the film material of the release film is selected from any one of polypropylene, polyethylene terephthalate and polyethylene.

4. The modified bituminous waterproofing membrane according to claim 1, wherein The polyvinylidene fluoride reflective weatherable surface layer comprises, by weight fraction: 60-80 parts of polyvinylidene fluoride resin, 5-25 parts of a copolymer of polyvinylidene fluoride and tetrafluoroethylene or hexafluoropropylene, 10-20 parts of titanium dioxide filler, 3-5 parts of functional additive, and 0.5-1.0 parts of anti-aging agent; The functional additive is an acrylic resin or an epoxy resin; The titanium dioxide includes rutile titanium dioxide and anatase titanium dioxide, and the ratio of the two is 4:1~1:4, and the particle size is 200-500nm.

5. The reflective modified bituminous waterproofing membrane according to claim 4, characterized in that, The polyvinylidene fluoride reflective weatherable surface layer is formed by casting after extrusion granulation of the polyvinylidene fluoride base material, the titanium dioxide filler, the functional additive and the anti-aging agent.

6. The modified bituminous waterproofing membrane according to claim 4, wherein the polymer is a copolymer of ethylene and butyl acrylate. The titanium dioxide is sodium silicate and aluminum sulfate modified titanium dioxide; The sodium silicate and aluminum sulfate modified titanium dioxide is obtained by the following steps: The titanium dioxide slurry with a mass fraction of 20%-40% is heated to 60-80℃, and stirred at a speed of 500-1000r / min for 10-30min, then sodium silicate solution is added and the pH is adjusted to 8-9, and then aged for 1-2h; Cool to 50-70℃, add aluminum sulfate at a speed of 200-400r / min, adjust the pH to 7-8, continue to age for 2-4h, and then wash and filter to obtain the sodium silicate and aluminum sulfate modified titanium dioxide.

7. The modified bituminous waterproofing membrane according to claim 1, wherein The intermediate skeleton barrier layer comprises, by weight fraction: 90-95 parts of polyethylene terephthalate, 3-5 parts of hollow microbeads, 2-3 parts of anatase titanium dioxide, and 0.5-1.0 parts of an anti-aging agent; The hollow microbeads are selected from any one of hollow glass microbeads, hollow ceramic, and hollow resin. The particle size of the hollow microbeads is 10-20 μm. The particle size of the anatase titanium dioxide is 200-500 nm.

8. The reflective modified bituminous waterproofing membrane according to claim 7, characterized in that, The intermediate skeleton barrier layer is obtained by casting after extrusion granulation of polyethylene terephthalate, hollow microbeads, anatase titanium dioxide, and an anti-aging agent.

9. A method for producing a reflective modified bitumen waterproofing membrane as claimed in any one of claims 1 to 8, characterized in that, The preparation method comprises: The polyvinylidene fluoride reflective weatherable surface layer, the intermediate skeleton barrier layer, and the metal barrier layer are stacked and glued in sequence, and after curing at 60-80°C for 120-170 h, a reflective composite surface film is obtained; The reflective composite surface film is flattened, and a self-adhesive modified asphalt layer is sprayed on the metal barrier layer under water quenching at 0-5°C. After the self-adhesive modified asphalt layer cools down to 60-90°C, the release backing film is attached, and after roller pressing and stress release treatment, the reflective modified asphalt waterproof coiled material is prepared.

10. The method of claim 9, wherein, The gluing uses polyurethane glue, the amount of which is 5-10 g / m 2 ; Preferably, the intermediate skeleton barrier layer is obtained by the following steps: The polyethylene terephthalate, hollow microbeads, anatase titanium dioxide, and anti-aging agent are mixed uniformly at a rotation speed of 100-300 r / min, then conveyed into a single screw extruder at 250-275°C for melting and extrusion, and the intermediate skeleton barrier layer is obtained by casting; Preferably, the polyvinylidene fluoride reflective weatherable surface layer is obtained by the following steps: The polyvinylidene fluoride resin, a copolymer of vinylidene fluoride and tetrafluoroethylene or hexafluoropropylene, titanium dioxide filler, functional additives, and anti-aging agent are added into a hopper, mixed uniformly, then conveyed into a twin screw extruder at 180-220°C for melting and extrusion granulation into white masterbatch with a diameter of 4-6 mm; The white masterbatch is conveyed into a single screw extruder and extruded at 200-220°C, and the polyvinylidene fluoride reflective weatherable surface layer is obtained by casting.

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