Modified asphalt sizing material, preparation method and vapor-permeable modified asphalt waterproof coiled material

Abstract

The invention relates to a modified asphalt sizing material, which is prepared from the following components in percentage by weight: 35.5 to 38.5 percent of 70 # asphalt, 6.5 to 9.5 percent of base oil, 4.5 to 5.5 percent of aromatic oil, 3.5 to 4.5 percent of SBS (Styrene Butadiene Styrene), 5.5 to 6.5 percent of SIS (Styrene Isoprene Styrene), 5.5 to 6.5 percent of SBR (Styrene Butadiene Rubber) powder, 1.9 to 2.1 percent of blocked isocyanate, 0.06 to 0.08 percent of activating agent, 4.5 to 5.5 percent of porous silicon dioxide and 24 to 30 percent of powder. The modified asphalt sizing material can trigger the activating agent to catalyze the deblocking of the blocked isocyanate at the processing temperature of 180 + / -2 DEG C to release-NCO groups, the-NCO groups can react with trace moisture in an asphalt system to generate CO2 gas, in the rubber layer forming process, CO2 is wrapped by the asphalt in a viscoelastic state to form a uniform closed-cell foam structure, and in the forming process of a rubber layer, the modified asphalt sizing material can be used for forming an asphalt layer. According to the structure, liquid water permeation is blocked by utilizing the characteristic that the surface tension of liquid water is greater than that of a bubble wall, and an initial channel is constructed for vapor diffusion; furthermore, closed-cell foam is bridged by utilizing nano-pores of porous silicon dioxide, a'nano-pore adsorption-micropore diffusion 'three-dimensional vapor-permeable network is constructed, diffusion and discharge of water vapor are accelerated, liquid water is further blocked, and dynamic balance of waterproofness and breathability is realized.

Description

Technical Field

[0001] This invention relates to the field of waterproof membrane technology, and in particular to a modified bitumen compound and its preparation method, and a breathable modified bitumen waterproof membrane. Background Technology

[0002] In the field of building waterproofing, self-adhesive modified bitumen waterproof membranes have become a core material for waterproofing and damp-proofing of roofs, basements, bathrooms, roof gardens, roads, bridges, tunnels, parking lots, and other projects due to their advantages such as convenient construction and reliable adhesion. However, in pursuit of rapid waterproofing, existing self-adhesive modified bitumen waterproof membranes typically employ a dense structure for both the main adhesive and the surface membrane. This results in insufficient breathability of the membrane. After a period of time, residual moisture in the substrate (such as concrete or mortar) expands under sunlight, easily forming voids between the membrane and the substrate, leading to problems such as water seepage and leakage. At the same time, the moisture in the enclosed environment can breed mold, further damaging the membrane's performance and the durability of the building structure, thus affecting the long-term reliability of the building waterproofing project.

[0003] In view of this, the present invention is hereby proposed. Summary of the Invention

[0004] To address the aforementioned technical problems, this invention provides a modified asphalt compound and its preparation method, as well as a breathable modified asphalt waterproof membrane.

[0005] The technical solution adopted in this invention is as follows:

[0006] In one aspect, this invention provides a modified asphalt compound, comprising, by weight percentage:

[0007] 70# asphalt 35.5-38.5%, base oil 6.5-9.5%, aromatic oil 4.5-5.5%, SBS 3.5-4.5%, SIS 5.5-6.5%, SBR powder 5.5-6.5%, blocked isocyanate 1.9-2.1%, activator 0.06-0.08%, porous silica 4.5-5.5%, powder 24-30%.

[0008] This invention proposes a modified asphalt compound that, at a processing temperature (180±2℃), can trigger the activator to catalyze the deblocking of blocked isocyanates, releasing -NCO groups. These groups react with trace amounts of moisture in the asphalt system to generate CO2 gas (R-NCO+H2O→R-NH2+CO2↑). During the molding process of the modified asphalt layer, the CO2 is encapsulated by the viscoelastic asphalt to form a uniform closed-cell foam structure (pore size 20-50μm). This structure utilizes the property that the surface tension of liquid water is greater than that of the pore wall to block liquid water penetration, while simultaneously creating an initial channel for water vapor diffusion. Furthermore, the closed-cell foam is bridged by the nanopores of porous silica to construct a three-dimensional vapor-permeable network of "nanopore adsorption-micropore diffusion," accelerating the diffusion and discharge of water vapor and further blocking liquid water. This solves the technical problem of traditional roll materials being "waterproof but not vapor-permeable, or vapor-permeable but not waterproof."

[0009] Preferably, the blocked isocyanate is ε-caprolactam-blocked HDI.

[0010] Preferably, the activator is dibutyltin dilaurate or zinc oxide.

[0011] Preferably, the average pore size of the porous silica is 3-7 nm.

[0012] Preferably, the viscosity of the 70# asphalt is 3000-12000 mPa·s, and the pour point is -5℃;

[0013] The base oil has a viscosity of 200-3000 mPa·s and a pour point of -25℃;

[0014] The molecular weights of both the SBS and the SIS are greater than 150,000.

[0015] The SBR powder has a binder content of 50-55%;

[0016] The powder is talc powder with a particle size of 200 mesh.

[0017] Another aspect of the present invention provides a method for preparing modified asphalt binder as described in any of the above technical solutions, comprising the following steps:

[0018] S1. Mix 70# asphalt, base oil and aromatic oil, heat to 148-152℃, stir for 25-35 minutes, and control the water content of the system to be 0.8-1.2%;

[0019] S2. Add SBR powder and stir at 150-165℃ for 55-65 minutes.

[0020] S3. Heat to 178-182℃, add SBS and SIS, and stir for 115-125 minutes.

[0021] S4. Maintain the temperature at 178-182℃, add the blocked isocyanate and activator, stir for 25-35 minutes, and then grind with a colloid mill for 60 minutes with a colloid mill gap of 0.25 mm.

[0022] S5. Maintain the temperature at 178-182℃, add porous silica and powder, and stir for 55-65 minutes to obtain the final product.

[0023] In another aspect, the present invention provides a breathable modified bitumen waterproof membrane, comprising, from top to bottom, a hydrophobic microporous TPU film layer, a modified bitumen adhesive layer, a butyl rubber pressure-sensitive self-adhesive layer, and a PET release film layer, wherein the modified bitumen adhesive layer is made from the modified bitumen adhesive described in any of the above technical solutions. Detailed Implementation

[0024] To better understand the above technical solutions, exemplary embodiments of the present invention will be described in more detail below.

[0025] In one aspect, this invention provides a modified asphalt compound, comprising, by weight percentage:

[0026] The composition includes 35.5-38.5% 70# asphalt, 6.5-9.5% base oil, 4.5-5.5% aromatic oil, 3.5-4.5% SBS, 5.5-6.5% SIS, 5.5-6.5% SBR powder, 1.9-2.1% blocked isocyanate, 0.06-0.08% activator, 4.5-5.5% porous silica, and 24-30% powder. In this invention, the blocked isocyanate is catalytically deactivated at processing temperature to react with moisture in the asphalt system, forming closed-cell foam that bridges with the nanopores of porous silica, thus achieving a dynamic balance between waterproofing and breathability in the main adhesive layer. Furthermore, the addition of SBS, SIS, and other components further ensures the low-temperature flexibility, peelability, and heat resistance of the adhesive layer.

[0027] In a preferred embodiment of the present invention, the blocked isocyanate is ε-caprolactam-blocked HDI. In this invention, ε-caprolactam-blocked HDI is selected as the foaming agent, with a deblocking temperature of 150-160℃, which is compatible with the processing temperature of the modified asphalt compound. At 180±2℃, sufficient release of -NCO groups and a controllable reaction rate are ensured, while avoiding localized, intense foaming, thus generating a uniform closed-cell foam structure. If the deblocking temperature of the blocked isocyanate is too high, insufficient release of -NCO groups will occur at the processing temperature, resulting in insufficient foaming and affecting the vapor permeability of the adhesive layer. If the deblocking temperature of the blocked isocyanate is too low, intense foaming will occur at the processing temperature, degrading the waterproofness of the adhesive layer.

[0028] In a preferred embodiment of the present invention, the activator is dibutyltin dilaurate or zinc oxide. In this invention, selecting dibutyltin dilaurate or zinc oxide as the activator can effectively control the foaming rate of the blocked isocyanate.

[0029] In a preferred embodiment of the present invention, the average pore size of the porous silica is 3-7 nm. In this invention, the porous silica with a nanopore size of 3-7 nm can effectively "bridge" the gaps in the closed-cell foam to form a continuous vapor permeable network, ensuring vapor permeability efficiency; at the same time, the size effect of the nanopores (< the critical permeability size of liquid water) and surface tension are used to prevent liquid water from passing through, forming a double barrier with the closed-cell foam structure.

[0030] In a preferred embodiment of the present invention, the viscosity of 70# asphalt is 3000-12000 mPa·s and the pour point is -5℃;

[0031] The base oil has a viscosity of 200-3000 mPa·s and a pour point of -25℃;

[0032] Both SBS and SIS have molecular weights greater than 150,000.

[0033] The SBR powder has a binder content of 50-55%;

[0034] The powder is talc powder with a particle size of 200 mesh.

[0035] Another aspect of the present invention provides a method for preparing modified asphalt binder as described in any of the above technical solutions, comprising the following steps:

[0036] S1. Mix 70# asphalt, base oil and aromatic oil, heat to 148-152℃, stir for 25-35 minutes, and control the water content of the system to be 0.8-1.2%;

[0037] S2. Add SBR powder and stir at 150-165℃ for 55-65 minutes.

[0038] S3. Heat to 178-182℃, add SBS and SIS, and stir for 115-125 minutes.

[0039] S4. Maintain the temperature at 178-182℃, add the blocked isocyanate and activator, stir for 25-35 minutes, and then grind with a colloid mill for 60 minutes with a colloid mill gap of 0.25 mm.

[0040] S5. Maintain the temperature at 178-182℃, add porous silica and powder, and stir for 55-65 minutes to obtain the final product.

[0041] In this invention, the degree of foaming reaction of the subsequent closed-cell isocyanate is regulated by controlling the moisture content in the asphalt system in step S1, ensuring that the number of closed-cell foams is appropriate, their morphology is intact, and their distribution is uniform. If the moisture content is too low, the foaming reaction will be incomplete, and the vapor permeability of the adhesive layer will decrease; if the moisture content is too high, the excess moisture cannot be completely consumed, which can easily cause the foam structure to merge or break, and the residual moisture may form bubble defects during the cooling process of the adhesive layer, thereby causing a decrease in the mechanical properties and waterproof performance of the adhesive layer.

[0042] In another aspect, this invention provides a breathable modified bitumen waterproof membrane, comprising, from top to bottom, a hydrophobic microporous TPU film layer, a modified bitumen adhesive layer, a butyl rubber pressure-sensitive self-adhesive layer, and a PET release film layer, wherein the modified bitumen adhesive layer is made from the modified bitumen adhesive of any of the above-mentioned technical solutions. In an embodiment of this invention, the hydrophobic microporous TPU film layer uses a TPU film material with a water contact angle ≥125°, a roll-off angle ≤10°, and an average pore size of 0.1-0.3μm, which helps to improve the waterproof and breathable properties of the membrane.

[0043] Example 1

[0044] A modified bitumen compound comprising, by weight percentage:

[0045] 37% of 70# asphalt (viscosity 8500 mPa·s, pour point -5℃), 8% of base oil (viscosity 1500 mPa·s, pour point -25℃), 5% of aromatic oil, 4% of SBS (model 1301), 6% of SIS (model 1105), 6% of SBR powder (rubber content 52%), 2% of blocked isocyanate (ε-caprolactam blocked HDI), 0.07% of activator (dibutyltin dilaurate), 5% of porous silica (average pore size 5 nm), and 26.93% of powder (talc, particle size 200 mesh).

[0046] The modified asphalt compound described above is prepared by the following method, including the following steps:

[0047] S1. Mix 70# asphalt, base oil and aromatic oil, heat to 150℃, stir at a frequency of 15Hz for 30 minutes, and control the water content of the system to 1%.

[0048] S2. Add SBR powder and stir for 60 min at a temperature of 155℃ and a frequency of 30Hz.

[0049] S3. Heat to 180℃, add SBS and SIS, and stir at 25Hz for 120min.

[0050] S4. Keep the temperature at 180℃, add the blocked isocyanate and activator, stir at a frequency of 25Hz for 30 minutes, and then grind with a colloid mill for 60 minutes with a colloid mill gap of 0.25mm.

[0051] S5. Maintain the temperature at 180℃, add porous silica and powder, and stir at a frequency of 30Hz for 60 minutes to obtain the final product.

[0052] The modified bitumen compound prepared according to the above method is used to prepare a breathable modified bitumen waterproof membrane. The specific method is as follows: after the modified bitumen compound is cooled to 160°C, it is coated onto a hydrophobic microporous TPU film layer through a steel belt production line and pre-cooled and shaped. Then, a butyl rubber pressure-sensitive self-adhesive layer is coated on the modified bitumen compound layer, and finally a PET release film layer is covered to obtain the breathable modified bitumen waterproof membrane.

[0053] Comparative Examples 1-2

[0054] The difference between this comparative example and Example 1 is that the amount of 70# asphalt used is different, and talc powder is used to adjust the total weight of the raw materials to 100%. The remaining steps remain unchanged.

[0055] Comparative Examples 3-4

[0056] The difference between this comparative example and Example 1 is that the amount of base oil used is different, and talc is used to adjust the total weight of the raw materials to 100%. The remaining steps remain unchanged.

[0057] Comparative Examples 5-6

[0058] The difference between this comparative example and Example 1 is that the amount of aromatic oil used is different, and talc powder is used to adjust the total weight of the raw materials to 100%. The remaining steps remain unchanged.

[0059] Comparative Examples 7-8

[0060] The difference between this comparative example and Example 1 is that the amount of SBS used is different, and talc is used to adjust the total weight of the raw materials to 100%. The remaining steps remain unchanged.

[0061] Comparative Examples 9-10

[0062] The difference between this comparative example and Example 1 is that the amount of SIS used is different, and talc is used to adjust the total weight of the raw materials to 100%. The remaining steps remain unchanged.

[0063] Comparative Examples 11-12

[0064] The difference between this comparative example and Example 1 is that the amount of SBR powder used is different, and talc is used to adjust the total weight of the raw materials to 100%. The remaining steps remain unchanged.

[0065] Comparative Examples 13-14

[0066] The difference between this comparative example and Example 1 is that the amount of ε-caprolactam blocking HDI is different, and talc is used to adjust the total weight of the raw materials to 100%. The remaining steps remain unchanged.

[0067] Comparative Examples 15-16

[0068] The difference between this comparative example and Example 1 is that the amount of dibutyltin dilaurate is different, and talc is used to adjust the total weight of the raw materials to 100%. The remaining steps remain unchanged.

[0069] Comparative Examples 17-18

[0070] The difference between this comparative example and Example 1 is that the amount of porous silica used is different, and talc powder is used to adjust the total weight of the raw materials to 100%. The remaining steps remain unchanged.

[0071] Comparative Example 19

[0072] The difference between this comparative example and Example 1 is that the water content of the system is controlled at 2% in step S1. The remaining steps remain unchanged.

[0073] Comparative Example 20

[0074] The difference between this comparative example and Example 1 is that the water content of the system is controlled at 0.3% in step S1. The remaining steps remain unchanged.

[0075] For comparative examples 1-18, please refer to Table 1 for the dosage of each component of the raw materials.

[0076] Table 1

[0077]

[0078]

[0079] The waterproof membranes prepared in Example 1 and Comparative Examples 1-20 were subjected to performance tests, and the results are recorded in Table 2. The vapor permeability test method refers to GB / T 17146, the water impermeability test method refers to GB / T 328.10, and the remaining performance refers to the N-type II product standard for non-woven membranes in GB / T 23441.

[0080] Table 2

[0081]

[0082]

[0083] As shown in Table 2, all indicators of the breathable modified bitumen waterproof membrane prepared in the embodiments of the present invention meet the standards. Comparing Example 1 with Comparative Examples 1-4, it can be seen that the bitumen content has a significant impact on heat resistance and low-temperature flexibility. Comparing with Comparative Examples 3-4, it can be seen that the base oil has a high pour point and low viscosity. When the base oil content is too low, the low-temperature flexibility and low-temperature flexibility after heat aging are unqualified; when the base oil content is too high, both heat resistance and peel performance are unqualified. Comparing with Comparative Examples 5-6, it can be seen that the aromatic oil has a low pour point. When the aromatic oil content is too low, the peel performance is not met; when the aromatic oil content is too high, the low-temperature flexibility before and after aging is not met. Compared with Comparative Examples 7-10, it can be seen that when SBS is combined with SIS to construct a macromolecular framework, SBS has greater cohesion, providing strength, while SIS has relatively longer chain segments, better flexibility, and is more beneficial at low temperatures. When the SBS addition is less than 3.5%, the polymer structure strength of the material is low, and aging degradation is severe; when the SBS addition is more than 4.5%, the material skeleton strength is too high, leading to a sharp decline in peel performance; when the SIS addition is less than 5.5%, the low-temperature margin is small, and the low-temperature performance is unqualified before and after thermal aging. Compared with Comparative Examples 11-12, it can be seen that the amount of SBR powder mainly affects the adhesive properties. When its amount is too low, the peel performance of the roll material decreases, and further increasing its amount to 7% does not significantly improve the peel performance. Compared with Comparative Examples 13-20, it can be seen that too low the content of ε-caprolactam-blocked HDI, dibutyltin dilaurate, and porous silica, as well as too low the moisture content of the asphalt system, are all detrimental to vapor permeability. Too high the content of the above components and too high the moisture content of the asphalt system are detrimental to waterproofing.

[0084] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A modified asphalt binder, characterized in that, Including by weight percentage: 70# asphalt 35.5-38.5%, base oil 6.5-9.5%, aromatic oil 4.5-5.5%, SBS 3.5-4.5%, SIS 5.5-6.5%, SBR powder 5.5-6.5%, blocked isocyanate 1.9-2.1%, activator 0.06-0.08%, porous silica 4.5-5.5%, powder 24-30%.

2. The modified asphalt compound as described in claim 1, characterized in that, The blocked isocyanate is ε-caprolactam-blocked HDI.

3. The modified asphalt compound as described in claim 1, characterized in that, The activator is dibutyltin dilaurate or zinc oxide.

4. The modified asphalt compound as described in claim 1, characterized in that, The average pore size of the porous silica is 3-7 nm.

5. The modified asphalt compound as described in claim 1, characterized in that, The viscosity of the 70# asphalt is 3000-12000 mPa·s, and the pour point is -5℃; The base oil has a viscosity of 200-3000 mPa·s and a pour point of -25℃; The molecular weights of both the SBS and the SIS are greater than 150,000. The SBR powder has a binder content of 50-55%; The powder is talc powder with a particle size of 200 mesh.

6. A method for preparing modified asphalt binder as described in any one of claims 1-5, characterized in that, Includes the following steps: S1. Mix 70# asphalt, base oil and aromatic oil, heat to 148-152℃, stir for 25-35 minutes, and control the water content of the system to be 0.8-1.2%; S2. Add SBR powder and stir at 150-165℃ for 55-65 minutes. S3. Heat to 178-182℃, add SBS and SIS, and stir for 115-125 minutes. S4. Keep the temperature at 178-182℃, add the blocked isocyanate and activator, stir for 25-35 minutes, and then grind with a colloid mill for 60 minutes with a colloid mill gap of 0.25 mm. S5. Maintain the temperature at 178-182℃, add porous silica and powder, and stir for 55-65 minutes to obtain the final product.

7. A breathable modified bitumen waterproof membrane, characterized in that, From top to bottom, it comprises a hydrophobic microporous TPU film layer, a modified asphalt adhesive layer, a butyl rubber pressure-sensitive self-adhesive layer, and a PET release film layer, wherein the modified asphalt adhesive layer is made from the modified asphalt adhesive as described in any one of claims 1-5.

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