Super-weather-resistant plant-based asphalt waterproof coiled material and preparation method thereof

Abstract

The invention discloses a super-weather-resistant plant-based asphalt waterproof coiled material and a preparation method thereof, and relates to the technical field of waterproof coiled material preparation. The polarity of the cottonseed oil asphalt is reduced through esterification reaction, the compatibility of the cottonseed oil asphalt and the petroleum-based asphalt is improved, and meanwhile oil loss and microbial erosion are inhibited through the inner storage and outer locking mechanism of the modified pine fibers. The scheme breaks through the limitations of low replacement rate, high cost and complex process of plant-based asphalt in the traditional technology, improves the replacement rate of cottonseed oil asphalt to 75%, and realizes collaborative optimization of performance, cost and environmental protection through high-proportion utilization of industrial waste (waste tire rubber powder).

Description

Technical Field

[0001] This invention relates to the field of waterproof membrane preparation technology, specifically to an ultra-weather-resistant plant-based bitumen waterproof membrane and its preparation method. Background Technology

[0002] In practical applications, plant-based asphalt faces a significant bottleneck: insufficient weather resistance severely limits its service life and performance stability. Plant-based asphalt is mainly composed of heavy oils, lignin, cellulose, hemicellulose, and other biomass components. It was previously believed that these natural materials contain a large number of easily oxidized active groups in their molecular structure, making them prone to degradation, aging, and performance deterioration under the influence of ultraviolet radiation, rainwater, and high / low temperature cycles.

[0003] The main factors affecting the durability of plant-based materials include oil loss, with an average annual oil loss rate of about 3% in plant-based bitumen under ideal conditions; and the fermentation and decay of polysaccharides such as hemicellulose, which leads to microbial growth. Unmodified plant-based bitumen waterproof membranes exhibit reduced low-temperature flexibility after 12 months of outdoor exposure, and may even crack and leak.

[0004] Therefore, how to effectively improve the weather resistance of plant-based bitumen and solve its long-term service in complex climatic environments has become a key technical challenge that needs to be overcome to promote the large-scale application of plant-based waterproof materials.

[0005] Meanwhile, for plant-based bitumen, the proportion of its additives is inversely proportional to its durability. Although adding plant-based bitumen to petrochemical bitumen can reduce the use of petroleum feedstocks, the resulting bitumen waterproof membranes are prone to degradation and performance deterioration under environmental factors such as ultraviolet radiation, temperature and humidity cycles, and rainwater erosion, thus limiting their application in the field of waterproof membranes for a long time.

[0006] This limits the amount of plant-based bitumen used in waterproof membranes; generally, the amount of plant-based bitumen used in waterproof membranes does not exceed 15%. This very low amount limits the application of plant-based bitumen in bituminous waterproof membranes. Summary of the Invention

[0007] The purpose of this invention is to provide an ultra-weather-resistant plant-based bitumen waterproof membrane and its preparation method, so as to solve the contradiction between improving weather resistance and low-doping environmental protection.

[0008] To solve the above problems, the present invention employs the following technical means: A super weather-resistant plant-based bitumen waterproof membrane includes a bitumen mixture, naphthenic oil, pine fiber, waste tire rubber powder, and calcite powder; The asphalt mixture comprises 75% modified cottonseed oil asphalt and 25% petroleum-based asphalt. The pine fiber serves as a reinforcing filler phase, and the naphthenic oil is adsorbed within the pine fiber.

[0009] In this process, pine fibers are used to adsorb naphthenic oil. When pine fibers are saturated with adsorbed naphthenic oil, they act as a locking agent within the mixed asphalt matrix, forming a physical barrier that increases the mechanical properties of the waterproof membrane while inhibiting the volatilization of oil in the plant-based asphalt membrane. Furthermore, by impregnating pine fibers with naphthenic oil to saturation, the pine fibers, acting as a reinforcing phase fixed within the mixed asphalt matrix, allow for the slow release of adsorbed naphthenic oil during membrane use, even after the oil in the matrix has volatilized. This replenishes the oil content in the plant-based asphalt.

[0010] Furthermore, through the dual effects of locking in oil and slowly releasing and replenishing oil, it effectively ensures the weather resistance of mixed bitumen waterproof membranes with a high proportion of plant-based bitumen.

[0011] Preferably, the modified cottonseed oil asphalt is modified using 2% sulfonic acid resin as a catalyst and non-polar modification with ethanol.

[0012] Furthermore, the pine fiber is prepared from pine trees that are more than 5 years old.

[0013] Furthermore, by selecting high-strength, high-oil-content, low-hemicellulose, and low-sugar pine fibers, it is possible to ensure that pine fibers, as a reinforcing phase, impart high mechanical strength to the plant-based mixed asphalt roofing membrane. Simultaneously, it allows naphthenic oils to more fully fill the fiber cells and non-crystalline regions of the microfibrils. While ensuring good filling, the slow-release effect of pine fibers on naphthenic oils is utilized to continuously replenish the oils lost through volatilization in the plant-based mixed asphalt roofing membrane.

[0014] Furthermore, by weight percentage, it comprises 48% asphalt mixture, 9% naphthenic oil, 3% pine fiber, 20% waste tire rubber powder, and 20% calcite.

[0015] Furthermore, a method for preparing the aforementioned plant-based bitumen waterproof membrane includes: S1. Add 2% sulfonic acid resin as a catalyst to cottonseed oil pitch, then add excess ethanol, and react for 4 to 6 hours at 110 to 130°C. Thus, in the first step, sulfonic acid resin is used as a catalyst, and ethanol is used to esterify and modify cottonseed oil asphalt. By esterifying and modifying the polar groups on the outside of cottonseed oil asphalt, the cottonseed oil asphalt is made into a non-polar state. This allows for better compatibility between the two when a large amount of cottonseed oil asphalt is mixed with petroleum-based asphalt in the later stage.

[0016] S2. After filtration, the asphalt filter material is mixed with petroleum-based asphalt, and pine fibers that have been fully impregnated and adsorbed with naphthenic oil are added to prepare a coating material. The naphthenic oil that fills the pine fiber not only replenishes the oil content, but also acts as a substitute for SBS filler modifier.

[0017] S3. After adding the coating material to the auxiliary materials, the coating is applied to obtain the finished product.

[0018] Furthermore, the sulfonic acid resin is mixed with the cottonseed oil pitch before the ethanol, stirred at 80°C, and then anhydrous ethanol is added, followed by reaction at 130°C for 4 hours.

[0019] Furthermore, the pine wood fiber is formed by drying and breaking down pine wood into independent fibers of 1000-3000 micrometers.

[0020] Furthermore, when using pine fiber to absorb naphthenic oil, the naphthenic oil and pine fiber are mixed in a mass ratio of 3:1 and heated and mixed at 180°C for 2 hours.

[0021] In this way, the pine fibers are fully combined with the naphthenic oil. During the filling process, the resin remaining in the pine fiber cells is dissolved, allowing the naphthenic oil to fully fill the interior of the pine fiber cells and the non-crystalline areas of the microfibrils.

[0022] Furthermore, the auxiliary materials are waste tire rubber powder and calcite powder.

[0023] Naphthenic oil, also used as an additive in waste tire rubber powder, can cause the waste tire rubber powder to swell, increasing its oil absorption and cross-linking degree. Pine fibers enriched with naphthenic oil can replace traditional waste tire rubber powder modifiers, achieving the same effect at high temperatures. Furthermore, the pine fibers can store oil, achieving a dual effect of slow oil release within the roll material and locking in oil loss externally, effectively ensuring the weather resistance of plant-based asphalt.

[0024] In summary, this application has the following beneficial effects: The cottonseed oil asphalt substitution rate was successfully increased to 75%, replacing a large amount of petroleum-based asphalt. The ethanol and sulfonic acid resin used in the reaction process can be recovered, meeting the necessary conditions for industrial-scale production. Simultaneously, the use of naphthenic oils instead of aromatic oils not only meets health requirements and aligns with the concept of green building materials, but also, through physical action, fills the molecular structure of asphalt and rubber, acting as a plasticizer and softener, improving the flexibility and deformation resistance of asphalt. Furthermore, the lower polarity of naphthenic oils helps delay the aging of asphalt and rubber.

[0025] In cottonseed oil-asphalt waterproof membranes, this invention innovatively incorporates pine fibers rich in naphthenic oil, achieving a dual optimization of product performance and weather resistance. The pine fibers play a crucial role; under normal circumstances, oil evaporation is approximately 3% annually. The pine fibers and asphalt mixture form a microscopic "reinforced concrete structure" that effectively locks in oil evaporation. Simultaneously, pretreatment ensures that the pine fibers store a large amount of naphthenic oil, which is slowly released during use, forming a continuous protective mechanism and significantly improving the weather resistance of the waterproof membrane. Data shows that the annual oil loss rate of exposed membranes is significantly reduced, from the normal 3% to 0.6%, a reduction of up to 80%. Detailed Implementation

[0026] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0027] Therefore, the following detailed description of embodiments of the present invention is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0028] It should be noted that, unless otherwise specified, the embodiments and features described in this invention can be combined with each other.

[0029] A plant-based bitumen waterproof membrane comprises a bitumen mixture, naphthenic oil, pine fiber, waste tire rubber powder, and calcite powder; The asphalt mixture comprises 75% modified cottonseed oil asphalt and 25% petroleum-based asphalt. The pine fiber serves as a reinforcing filler phase, and the naphthenic oil is adsorbed within the pine fiber.

[0030] In this process, pine fibers are used to adsorb naphthenic oil. When pine fibers are saturated with adsorbed naphthenic oil, they act as a locking agent within the mixed asphalt matrix, forming a physical barrier that increases the mechanical properties of the waterproof membrane while inhibiting the volatilization of oil in the plant-based asphalt membrane. Furthermore, by impregnating pine fibers with naphthenic oil to saturation, the pine fibers, acting as a reinforcing phase fixed within the mixed asphalt matrix, allow for the slow release of adsorbed naphthenic oil during membrane use, even after the oil in the matrix has volatilized. This replenishes the oil content in the plant-based asphalt.

[0031] Furthermore, through the dual effects of locking in oil and slowly releasing and replenishing oil, it effectively ensures the weather resistance of mixed bitumen waterproof membranes with a high proportion of plant-based bitumen.

[0032] Preferably, the modified cottonseed oil asphalt is modified using 2% sulfonic acid resin as a catalyst and non-polar modification with ethanol.

[0033] Furthermore, the pine fiber is prepared from pine trees that are more than 5 years old.

[0034] Furthermore, by selecting high-strength, high-oil-content, low-hemicellulose, and low-sugar pine fibers, it is possible to ensure that pine fibers, as a reinforcing phase, impart high mechanical strength to the plant-based mixed asphalt roofing membrane. Simultaneously, it allows naphthenic oils to more fully fill the fiber cells and non-crystalline regions of the microfibrils. While ensuring good filling, the slow-release effect of pine fibers on naphthenic oils is utilized to continuously replenish the oils lost through volatilization in the plant-based mixed asphalt roofing membrane.

[0035] Furthermore, by weight percentage, it comprises 48% asphalt mixture, 9% naphthenic oil, 3% pine fiber, 20% waste tire rubber powder, and 20% calcite.

[0036] Furthermore, a method for preparing the aforementioned plant-based bitumen waterproof membrane includes: S1. Add 2% sulfonic acid resin as a catalyst to cottonseed oil pitch, then add excess ethanol, and react for 4 to 6 hours at 110 to 130°C. Thus, in the first step, sulfonic acid resin is used as a catalyst, and ethanol is used to esterify and modify cottonseed oil asphalt. By esterifying and modifying the polar groups on the outside of cottonseed oil asphalt, the cottonseed oil asphalt is made into a non-polar state. This allows for better compatibility between the two when a large amount of cottonseed oil asphalt is mixed with petroleum-based asphalt in the later stage.

[0037] S2. After filtration, the asphalt filter material is mixed with petroleum-based asphalt, and pine fibers that have been fully impregnated and adsorbed with naphthenic oil are added to prepare a coating material. The naphthenic oil that fills the pine fiber not only replenishes the oil content, but also acts as a substitute for SBS filler modifier.

[0038] S3. After adding the coating material to the auxiliary materials, the coating is applied to obtain the finished product.

[0039] Furthermore, the sulfonic acid resin is mixed with the cottonseed oil pitch before the ethanol, stirred at 80°C, and then anhydrous ethanol is added, followed by reaction at 130°C for 4 hours.

[0040] Furthermore, the pine wood fiber is formed by drying and breaking down pine wood into independent fibers of 1000-3000 micrometers.

[0041] Furthermore, when using pine fiber to absorb naphthenic oil, the naphthenic oil and pine fiber are mixed in a mass ratio of 3:1 and heated and mixed at 180°C for 2 hours.

[0042] In this way, the pine fibers are fully combined with the naphthenic oil. During the filling process, the resin remaining in the pine fiber cells is dissolved, allowing the naphthenic oil to fully fill the interior of the pine fiber cells and the non-crystalline areas of the microfibrils.

[0043] Furthermore, the auxiliary materials are waste tire rubber powder and calcite powder.

[0044] Naphthenic oil, also used as an additive in waste tire rubber powder, can cause the waste tire rubber powder to swell, increasing its oil absorption and cross-linking degree. Pine fibers enriched with naphthenic oil can replace traditional waste tire rubber powder modifiers, achieving the same effect at high temperatures. Furthermore, the pine fibers can store oil, achieving a dual effect of slow oil release within the roll material and locking in oil loss externally, effectively ensuring the weather resistance of plant-based asphalt.

[0045] The following detailed description is based on specific embodiments.

[0046]

[0047] Performance tests were conducted on Comparative Examples 1 to 6 in accordance with the relevant requirements of Type I in GB 23441-2007 "Self-adhesive Polymer Modified Bituminous Waterproof Membrane". The main tests included six indicators: heat resistance, low-temperature flexibility, impermeability, peel strength, oil penetration, and thermal aging.

[0048] Based on the principle of accelerated aging (Arrhenius equation), environmental parameters were enhanced, and an artificial climate aging chamber was used to test the weather resistance of roll materials. During natural aging, the aging rate of roll materials is affected by a combination of factors including temperature, light, and humidity. It is generally believed that the chemical reaction rate approximately doubles for every 10°C increase in temperature; increased ultraviolet radiation intensity can directly accelerate the photo-oxidative degradation of materials. Therefore, it is necessary to shorten the aging time by increasing stress parameters (such as temperature, light intensity, wind speed, and humidity) while ensuring that the parameter combination is consistent with the degradation mechanism of the natural environment.

[0049] Parameter settings: Ultraviolet light 340nm, 0.8W / ㎡•nm, total radiation approximately 120W / ㎡•day over 16 hours, cumulative radiation approximately 3240W / ㎡ over 3 months, equivalent natural radiation approximately 54,000 MJ / ㎡ (close to 10-year values). Temperature: Daytime 65℃, Nighttime 50℃, average temperature 57.5℃ over 12 hours, acceleration factor approximately 25-30 times, combined with light to achieve a total acceleration factor of approximately 40 times. Humidity: 60% in dry season (12 hours), 90% in rainy season (water spray, 12 hours), water sprayed 3 times a week (30 minutes / time) to simulate alternating dry and wet conditions. Wind speed: 4m / s, continuously activated to promote surface oxygen exchange and heat dissipation.

[0050] Remove the specimens for weighing and repeat the relevant requirements for Type I of GB 23441-2007 "Self-adhesive polymer modified bitumen waterproof membrane".

[0051] The test results are as follows:

[0052] In summary, the formulation and performance data of Comparative Examples 1-6 show that the material properties exhibit a regular change when the cottonseed oil bitumen substitution rate increases from 0% to 75%. Regarding heat resistance, the national standard requires waterproof membranes to withstand temperatures up to 70℃ without slippage. Comparative Example 1, using 36% unmodified cottonseed oil bitumen, has a heat resistance of only 51℃, far below the standard. While Comparative Examples 2-4 show improvements, Comparative Example 5, with a heat resistance of 84℃, is at a relatively high level among the comparative examples, maintaining stability in high-temperature environments and avoiding slippage and deformation due to high temperatures, thus ensuring waterproofing effectiveness. Low-temperature flexibility is crucial for the crack resistance of waterproof membranes in low-temperature environments. The standard requires low-temperature flexibility to reach -20℃ without cracks. Comparative Example 5 achieves a low-temperature flexibility of -29℃, far exceeding the national standard and performing exceptionally well among all comparative examples, only 3℃ lower than Comparative Example 1, which has the best low-temperature flexibility. Its impermeability remains at 0.5MPa, and all indicators exceed the GB23441-2007 Type I standard.

[0053] In Comparative Example 5, pine fiber was added, and other corresponding embodiments were set up as follows:

[0054] Comparing Comparative Examples 5 to 11, when the addition amount increased from 0 to 3%, the heat resistance of the roll material increased from 81℃ (Comparative Example 5) to 115℃ (Example 1), an increase of 42%; however, after exceeding 3% (4%), the viscosity of the mixture increased sharply, making the coating process impossible and production impossible. 3% pine fiber improves weather resistance through a dual effect of "internal storage and external locking"—the micropores inside the fiber store oil (filled with naphthenic oil during pretreatment), and a physical barrier is formed on the outside to inhibit oil volatilization, reducing the average annual oil loss rate from 3% to 0.6%.

[0055] Furthermore, this application also provides the following examples for different amounts of naphthenic oil added:

[0056] Regarding the weather resistance of Comparative Example 5 and Examples 1 to 3, the results are as follows:

[0057] The results in the table above show that Example 1, with the addition of 3% pine fiber, had a weight loss rate of only 2.14% after 2160 hours of artificial climate aging, which is 87.5% lower than that of Comparative Example 5 (17.10%) without fiber, confirming the key role of the 3% addition in delaying aging. Furthermore, the addition of 3% fiber did not significantly increase costs (fillers such as calcite powder can be adjusted accordingly), achieving a balance between performance optimization and process feasibility.

[0058] Regarding the performance parameters of Examples 1 to Comparative Examples 3, Example 3 (12% petrochemical asphalt, 36% cottonseed oil asphalt, 3% pine fiber, 9% naphthenic oil, 20% rubber powder, and 20% stone powder) showed significant advantages: Performance fully met standards: heat resistance 83℃ (standard ≥70℃), low-temperature flexibility -25℃ (standard ≤-20℃), water impermeability 0.5MPa (standard ≥0.3MPa), and peel strength (roll and aluminum sheet) reached 3.06N / mm, an improvement of 104% compared to the standard value; outstanding weather resistance, with a weight loss of only 2.24% after artificial aging, low-temperature flexibility maintained at -21℃, and peel strength of 2.01N / mm, all superior to Examples 1 and 2, verifying the effectiveness of the formulation optimization.

[0059] In terms of cost, it is ahead of the competition: the cost per ton is 3100 yuan, which is 8.8% lower than Example 1 and 8.8% lower than Comparative Example 5. This is because it completely eliminates tire rubber powder modifiers (which are more expensive) and achieves performance substitution through the synergistic effect of pine fiber and naphthenic oil. This formula not only meets all the indicators of GB23441-2007, but its cost performance is also significantly competitive among similar plant-based roll materials, providing data support for industrialization and promotion.

[0060] Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. 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 super weather-resistant plant-based bitumen waterproof membrane, characterized in that, Including asphalt mixtures, naphthenic oil, pine fiber, waste tire rubber powder, and calcite powder; The asphalt mixture comprises 75% modified cottonseed oil asphalt and 25% petroleum-based asphalt. The pine fiber serves as a reinforcing filler phase, and the naphthenic oil is adsorbed within the pine fiber.

2. The ultra-weather-resistant plant-based bitumen waterproof membrane according to claim 1, characterized in that, The modified cottonseed oil asphalt is non-polar modified using ethanol with 2% sulfonic acid resin as a catalyst.

3. The ultra-weather-resistant plant-based bitumen waterproof membrane according to claim 1, characterized in that, The pine fiber is prepared from pine trees that are more than 5 years old.

4. A super weather-resistant plant-based bitumen waterproof membrane according to any one of claims 1 to 3, characterized in that, By weight percentage, it comprises 48% bitumen mixture, 9% naphthenic oil, 3% pine fiber, 20% waste tire rubber powder, and 20% calcite.

5. A method for preparing an ultra-weather-resistant plant-based bitumen waterproof membrane according to any one of claims 1 to 4, characterized in that, include: S1. Add 2% sulfonic acid resin as a catalyst to cottonseed oil pitch, then add excess ethanol, and react for 4 to 6 hours at 110 to 130°C. S2. After filtration, the asphalt filter material is mixed with petroleum-based asphalt, and pine fibers that have been fully impregnated and adsorbed with naphthenic oil are added to prepare a coating material. S3. After adding the coating material to the auxiliary materials, the coating is applied to obtain the finished product.

6. The preparation method according to claim 5, characterized in that, The sulfonic acid resin is mixed with the cottonseed oil asphalt before the ethanol is added, stirred at 80°C, and then anhydrous ethanol is added, followed by reaction at 130°C for 4 hours.

7. The preparation method according to claim 5, characterized in that, The pine wood fiber is made by drying and breaking down pine wood to form independent fibers of 1000-3000 micrometers.

8. The preparation method according to claim 7, characterized in that, When using pine fiber to absorb naphthenic oil, the naphthenic oil and pine fiber are mixed at a mass ratio of 3:1 and heated and mixed at 180°C for 2 hours.

9. The preparation method according to claim 5, characterized in that, The auxiliary materials are waste tire rubber powder and calcite powder.

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