Preparation method of weather-resistant chlorinated polyethylene waterproof coiled material

Abstract

The application discloses a kind of preparation methods of weather-resistant chlorinated polyethylene waterproofing membrane, belong to the technical field of preparation chlorinated polyethylene waterproofing membrane, the preparation method includes: preparation intercalation hydrotalcite, handle white carbon black, material, mix material;The preparation intercalation hydrotalcite, after mixing magnesium-aluminum hydrotalcite, water, stirring at room temperature, add lanthanum nitrate hexahydrate, polyethylene glycol octylphenyl ether, stirring at 80 DEG C, add polyethylene glycol 200, stirring at 80 DEG C, cool to room temperature, centrifugal, take precipitate, after washing with water and drying, obtain intercalation hydrotalcite.The weather-resistant chlorinated polyethylene waterproofing membrane prepared by the application has good weather resistance, low preparation cost, good mechanical properties and waterproof performance, and good processing performance.

Description

Technical Field

[0001] This invention relates to the field of chlorinated polyethylene waterproof membrane technology, and specifically to a method for preparing weather-resistant chlorinated polyethylene waterproof membrane. Background Technology

[0002] Polymer waterproof membranes are flexible and bendable waterproof materials at room temperature. These membranes are made from synthetic polymers and complementary additives such as performance enhancers, processing aids, and fillers. Polymer waterproof membranes offer advantages such as good product uniformity, excellent chemical resistance, good weather resistance, low density, and light weight. Furthermore, they maintain good flexibility even at low temperatures.

[0003] Depending on the raw materials, polymer waterproof membranes are mainly classified into EPDM rubber waterproof membranes, polyvinyl chloride (PVC) waterproof membranes, chlorinated polyethylene (CPE) waterproof membranes, thermoplastic polyolefin waterproof membranes, and chlorinated polyethylene-rubber blend waterproof membranes. Among them, chlorinated polyethylene (CPE) waterproof membranes have the advantages of abundant raw materials, lower price, and simple processing. Furthermore, from the structural perspective of chlorinated polyethylene resin, because the chlorinated polyethylene molecular chain does not contain double bonds, chlorinated polyethylene materials have good heat resistance and UV resistance, and can maintain good performance under certain acidic and alkaline environments. Moreover, the polar chlorine atoms in chlorinated polyethylene give it excellent resistance to polar substances, such as oil resistance. As a halogen atom, chlorine provides excellent flame retardant properties, so chlorinated polyethylene materials also possess a certain degree of flame retardancy. Furthermore, the chlorine atoms on the chlorinated polyethylene molecular chain are randomly distributed, resulting in a random distribution of polar and nonpolar bonds. This causes different regions of the molecular chain to exhibit polar and nonpolar characteristics, giving chlorinated polyethylene excellent filling and blending properties. It can accommodate both polar and nonpolar additives, thereby enhancing its overall performance and broadening its application areas. Based on these advantages, chlorinated polyethylene waterproof membranes are among the most common waterproof membranes in the building waterproofing industry.

[0004] However, as published in "Preparation and Performance Research of High-Strength Chlorinated Polyethylene Waterproof Membrane" by Zhang Guangbin et al., *China Building Waterproofing*, 2010, chlorinated polyethylene waterproof membranes have been used in my country's building waterproofing field for over 20 years, and began to be applied to the waterproofing of railway concrete bridge decks at the end of the last century. However, in recent years, due to the insufficient weather resistance (aging resistance) of chlorinated polyethylene waterproof membranes, their application in the building waterproofing field has been declining year by year. Analysis shows that the insufficient weather resistance of chlorinated polyethylene waterproof membranes is mainly due to the following two reasons: The first reason is inherent to chlorinated polyethylene itself. For example, a preliminary study on the aging performance of chlorinated polyethylene waterproofing materials, published in *Preliminary Study on the Aging Performance of Chlorinated Polyethylene Waterproofing Materials* by Li Liying, *China High-Tech Enterprises*, 2017, defines aging as the phenomenon where, during use and storage, external factors such as light, heat, oxygen, water, and microorganisms cause changes in the chemical composition and structure of materials, leading to a decline in performance, such as hardening, stickiness, brittleness, discoloration, and reduced strength. During application, chlorinated polyethylene waterproofing materials are easily affected by external factors, causing changes in their internal structure, resulting in the replacement of some main chain hydrogen atoms with chlorine atoms. This significantly reduces their heat resistance, oxidation resistance, and oil resistance, leading to aging and affecting the application benefits of chlorinated polyethylene waterproofing materials to a certain extent. The literature also conducted xenon lamp weathering aging tests and hot air aging tests, finding that light and temperature accelerate the aging of chlorinated polyethylene waterproofing materials.

[0005] The second reason is the influence of processing aids. For example, as published in "Research Progress and Prospect of Chlorinated Polyethylene Waterproof Membranes" by Zhou Zhiyi et al., Modern Chemical Industry Research, 2018, processing aids can affect the weather resistance of chlorinated polyethylene waterproof membranes, and the migration of plasticizers is the main factor affecting the thermal aging of chlorinated polyethylene waterproof membranes.

[0006] The third reason is the influence of processing temperature. As published in the "Research Progress and Prospect of Chlorinated Polyethylene Waterproof Membrane" by Zhou Zhiyi et al. in "Modern Chemical Industry Research" in 2018, higher processing temperatures can easily cause chlorinated polyethylene to degrade, thereby affecting the weather resistance of chlorinated polyethylene waterproof membranes.

[0007] To address the aforementioned issues, the most common improvement methods currently employed include selecting chlorinated polyethylene with good weather resistance, performing blending modification (e.g., adding heat stabilizers and light stabilizers), using plasticizers with good high-temperature exudation resistance (e.g., using diisodecyl phthalate as the main plasticizer and chlorinated paraffin as the auxiliary plasticizer), and reducing the processing temperature. However, these improvement methods have the following shortcomings: The first shortcoming is that, regarding heat stabilizers and light stabilizers, such as those described in *Preparation and Properties of Mg(OH)2-BA-MMA Hybrid Grafted Polymers* (Li Ruidi et al., *Modern Plastics Processing and Application*, 2020), inorganic small-molecule stabilizers can affect the mechanical properties of chlorinated polyethylene. Furthermore, they can also negatively impact the waterproofing performance of the prepared chlorinated polyethylene waterproof membrane. On the other hand, other stabilizers, such as metal soap stabilizers and organotin stabilizers, suffer from low efficiency and high cost, respectively, as described in *Synthesis and Performance Study of Novel Organic Polymer Heat Stabilizers* (Lü Chanting, *Dalian University of Technology*, 2007). Furthermore, as disclosed in the study on the thermal stability and properties of low residual crystallinity chlorinated polyethylene (Lin Heng, Nanjing University of Technology, 2003), the thermal degradation mechanism of chlorinated polyethylene is dehydrochlorination and oxidative degradation. However, the main function of existing stabilizers is to capture and absorb the hydrogen chloride produced during degradation, thereby reducing the autocatalytic degradation effect of hydrogen chloride on chlorinated polyethylene. Few stabilizers can simultaneously capture and absorb hydrogen chloride and inhibit oxidative degradation, resulting in poor stabilization effect of the stabilizers.

[0008] The second drawback is that plasticizers with good high-temperature exudation resistance generally have a larger molecular weight. As the molecular weight of the plasticizer increases, its effect on improving the processing performance of chlorinated polyethylene decreases, and it is more likely to cause processing difficulties at lower processing temperatures. Summary of the Invention

[0009] To address the shortcomings of existing technologies, this invention provides a method for preparing weather-resistant chlorinated polyethylene waterproof membrane. The prepared chlorinated polyethylene waterproof membrane exhibits good weather resistance, low preparation cost, good mechanical and waterproof properties, and good processability.

[0010] To solve the above technical problems, the technical solution adopted by the present invention is as follows: A method for preparing a weather-resistant chlorinated polyethylene waterproof membrane includes: preparing intercalated hydrotalcite, treating silica, preparing materials, and mixing materials. The preparation of intercalated hydrotalcite involves mixing magnesium aluminum hydrotalcite and water, stirring at 200-500 rpm for 30-40 minutes at room temperature, adding lanthanum nitrate hexahydrate and polyethylene glycol octylphenyl ether, stirring at 200-500 rpm for 30-40 minutes at 80°C, adding polyethylene glycol 200, stirring at 200-500 rpm for 30-40 minutes at 80°C, cooling to room temperature, centrifuging at 3000 rpm for 20-30 minutes at room temperature, collecting the precipitate, washing with water, and drying to obtain intercalated hydrotalcite. In the preparation of the intercalated hydrotalcite, the ratio of magnesium aluminum hydrotalcite, water, lanthanum nitrate hexahydrate, polyethylene glycol octylphenyl ether, and polyethylene glycol 200 is 100g:1000-1200mL:2.4-2.6g:10-12g:10-12g; The particle size of the magnesium aluminum hydrotalcite is 800-1200 mesh; The process for treating silica involves mixing silica and water, stirring at 200-500 rpm for 30-40 minutes at room temperature, adding sodium dodecylbenzenesulfonate and polyethylene glycol 400, stirring at 50-100 rpm for 2-3 hours at room temperature, centrifuging at 10000 rpm for 20-30 minutes at room temperature, collecting the precipitate, washing it with water, and drying it to obtain the treated silica. In the process of treating silica, the ratio of silica, water, sodium dodecylbenzenesulfonate, and polyethylene glycol 400 is 100g:1000-1200mL:9-10g:9-10g. The silica is precipitated silica with a particle size of 50-100 nm. The materials to be prepared, by weight, are 100 parts chlorinated polyethylene, 20-25 parts treated silica, 10-12 parts main plasticizer, 5-6 parts auxiliary plasticizer, 15-18 parts magnesium oxide, 1.8-2 parts stearic acid, and 3-3.2 parts intercalated hydrotalcite. In the preparation of the materials, the manufacturer of the chlorinated polyethylene is Weifang Shuoyi Chemical Co., Ltd., the brand name is CM3000, the chlorine content is 36%, and the Mooney viscosity ML(1+4) 125℃ is 80. The main plasticizer is dioctyl phthalate; The auxiliary plasticizer is chlorinated paraffin; The magnesium oxide has a particle size of 2-10 μm; The mixture is prepared by adding chlorinated polyethylene and treated silica to a high-speed mixer, followed by a first high-speed mixing. Then, the prepared main plasticizer, auxiliary plasticizer, magnesium oxide, stearic acid, and intercalated hydrotalcite are added to the high-speed mixer, followed by a second high-speed mixing. The mixture is then subjected to open milling and thin-passing, formed into triangular bales, and extruded into sheets to obtain chlorinated polyethylene waterproof membrane. In the mixing process, the temperature of the first high-speed stirring is 80-82℃, the stirring speed is 1000-1200rpm, and the time is 2-3min; The second high-speed stirring was carried out at a temperature of 80-82℃, a stirring speed of 1000-1200 rpm, and a time of 5-6 minutes. The roll temperature during the initial thin pass of the mill is 150-155℃; The number of times to apply the triangular bandage is 9-11.

[0011] Compared with the prior art, the beneficial effects of the present invention are as follows: (1) In preparing intercalated hydrotalcite, this invention references the synergistic effect of lanthanum(III) ions and nonionic surfactants on aluminum corrosion inhibition. Mu Guannan et al. Chemical Cleaning. 1996, which discloses the interaction between lanthanum ions and nonionic surfactants; it also references the progress in the application of organic modified hydrotalcite in PVC heat stabilizers. Yuan Haokun et al. Chemical Engineering Design Communications. 2022, which discloses that polyethylene glycol modified hydrotalcite has good thermal stability because the increase in the number and molecular weight of hydroxyl groups in polyhydroxy alcohols is beneficial to improving the compatibility and initial thermal stability of organic modified hydrotalcite with PVC; and it also references the study on the surface properties of anionic-nonionic surfactant composite modified hydrotalcite. Xu Jinfang et al. Journal of Inorganic Chemistry. 2014, which discloses... This invention employs two surfactants to modify hydrotalcite: polyethylene glycol octylphenyl ether (PEG) and polyethylene glycol 200. PEG and 200 are used to achieve uniform dispersion of lanthanum ions. As rare earth ions, lanthanum ions improve the weather resistance of chlorinated polyethylene and promote the fixation of PEG and 200 on the hydrotalcite surface. Furthermore, in treating silica, this invention utilizes the dispersing effects of sodium dodecylbenzenesulfonate (NDB) and polyethylene glycol 400. NDB and 400 work synergistically to achieve high adsorption on the silica surface, thereby further improving the weather resistance, mechanical properties, and processing performance of the prepared chlorinated polyethylene. (2) The chlorinated polyethylene waterproof membrane prepared by the present invention has a Mooney viscosity of 10.04-10.81 at 165℃, a tensile strength of 12.5-13.8 MPa, an elongation at break of 628.0-662.3%, a dimensional change rate (transverse) of 0.8-1.1% after heat treatment, a dimensional change rate (longitudinal) of 0.6-0.9% after heat treatment, no cracks at low temperature bending at -25℃, impermeability, and water impermeability. After xenon lamp aging test, the tensile strength decreases by 5.2-5.7%, the elongation at break decreases by 6.9-7.5%, the tensile strength decreases by 7.7-8.4%, and the elongation at break decreases by 7.9-8.1% after hot air aging test. Detailed Implementation

[0012] To provide a clearer understanding of the technical features, objectives, and effects of the present invention, specific embodiments of the present invention are now described.

[0013] Example 1 A method for preparing a weather-resistant chlorinated polyethylene waterproof membrane is as follows: 1. Preparation of intercalated hydrotalcite: 100g magnesium aluminum hydrotalcite and 1000mL water were mixed and stirred at 200rpm for 30min at room temperature. 2.4g lanthanum nitrate hexahydrate and 10g polyethylene glycol octylphenyl ether were added and stirred at 200rpm for 30min at 80℃. 10g polyethylene glycol 200 was added and stirred at 200rpm for 30min at 80℃. The mixture was cooled to room temperature and centrifuged at 3000rpm for 20min at room temperature. The precipitate was collected, washed with water, and dried to obtain intercalated hydrotalcite. The magnesium aluminum hydrotalcite has a particle size of 1000 mesh; 2. Treatment of silica: Mix 100g silica and 1000mL water, stir at 200rpm for 30min at room temperature, add 9g sodium dodecylbenzenesulfonate and 9g polyethylene glycol 400, stir at 50rpm for 2h at room temperature, centrifuge at 10000rpm for 20min at room temperature, collect the precipitate, wash with water and dry to obtain the treated silica; The silica is precipitated silica with a particle size of 100 nm. 3. Material preparation: By weight, prepare 100 parts of chlorinated polyethylene, 20 parts of treated silica, 10 parts of main plasticizer, 5 parts of auxiliary plasticizer, 15 parts of magnesium oxide, 1.8 parts of stearic acid, and 3 parts of intercalated hydrotalcite. The chlorinated polyethylene is manufactured by Weifang Shuoyi Chemical Co., Ltd., with the brand name CM3000, a chlorine content of 36%, and a Mooney viscosity ML(1+4) of 80 at 125°C. The main plasticizer is dioctyl phthalate; The auxiliary plasticizer is chlorinated paraffin; The magnesium oxide has a particle size of 5 μm; 4. Mixing: Add the prepared chlorinated polyethylene and treated silica to the high-speed mixer and stir at 1000 rpm for 2 minutes at 80°C. Continue to add the prepared main plasticizer, auxiliary plasticizer, magnesium oxide, stearic acid, and intercalated hydrotalcite to the high-speed mixer and stir at 1000 rpm for 5 minutes at 80°C. Transfer to the open mill, set the roller temperature to 150°C, and perform open milling and thin-pass milling. Make 10 triangular rolls and produce sheets to obtain chlorinated polyethylene waterproof membrane.

[0014] Example 2 A method for preparing a weather-resistant chlorinated polyethylene waterproof membrane is as follows: 1. Preparation of intercalated hydrotalcite: 100g magnesium aluminum hydrotalcite and 1000mL water were mixed and stirred at 200rpm for 30min at room temperature. 2.4g lanthanum nitrate hexahydrate and 10g polyethylene glycol octylphenyl ether were added and stirred at 200rpm for 30min at 80℃. 10g polyethylene glycol 200 was added and stirred at 200rpm for 30min at 80℃. The mixture was cooled to room temperature and centrifuged at 3000rpm for 20min at room temperature. The precipitate was collected, washed with water, and dried to obtain intercalated hydrotalcite. The magnesium aluminum hydrotalcite has a particle size of 1000 mesh; 2. Treatment of silica: Mix 100g silica and 1000mL water, stir at 200rpm for 30min at room temperature, add 9g sodium dodecylbenzenesulfonate and 9g polyethylene glycol 400, stir at 50rpm for 2h at room temperature, centrifuge at 10000rpm for 20min at room temperature, collect the precipitate, wash with water and dry to obtain the treated silica; The silica is precipitated silica with a particle size of 100 nm. 3. Material preparation: By weight, prepare 100 parts of chlorinated polyethylene, 25 parts of treated silica, 12 parts of main plasticizer, 6 parts of auxiliary plasticizer, 18 parts of magnesium oxide, 2 parts of stearic acid, and 3.2 parts of intercalated hydrotalcite. The chlorinated polyethylene is manufactured by Weifang Shuoyi Chemical Co., Ltd., with the brand name CM3000, a chlorine content of 36%, and a Mooney viscosity ML(1+4) of 80 at 125°C. The main plasticizer is dioctyl phthalate; The auxiliary plasticizer is chlorinated paraffin; The magnesium oxide has a particle size of 5 μm; 4. Mixing: Add the prepared chlorinated polyethylene and treated silica to the high-speed mixer. Mix at 1200 rpm for 2-3 minutes at 82°C. Continue to add the prepared main plasticizer, auxiliary plasticizer, magnesium oxide, stearic acid, and intercalated hydrotalcite to the high-speed mixer. Mix at 1200 rpm for 6 minutes at 82°C. Transfer to an open mill, set the roller temperature to 155°C, and perform open milling and thin-pass milling. Make 10 triangular rolls and produce sheets to obtain chlorinated polyethylene waterproof membrane.

[0015] Example 3 A method for preparing a weather-resistant chlorinated polyethylene waterproof membrane is as follows: 1. Preparation of intercalated hydrotalcite: 100g magnesium aluminum hydrotalcite and 1200mL water were mixed and stirred at 500rpm for 40min at room temperature. 2.6g lanthanum nitrate hexahydrate and 12g polyethylene glycol octylphenyl ether were added and stirred at 500rpm for 40min at 80℃. 12g polyethylene glycol 200 was added and stirred at 500rpm for 40min at 80℃. The mixture was cooled to room temperature and centrifuged at 3000rpm for 30min at room temperature. The precipitate was collected, washed with water, and dried to obtain intercalated hydrotalcite. The magnesium aluminum hydrotalcite has a particle size of 1000 mesh; 2. Treatment of silica: Mix 100g silica and 1000mL water, stir at 200rpm for 30min at room temperature, add 9g sodium dodecylbenzenesulfonate and 9g polyethylene glycol 400, stir at 50rpm for 2h at room temperature, centrifuge at 10000rpm for 20min at room temperature, collect the precipitate, wash with water and dry to obtain the treated silica; The silica is precipitated silica with a particle size of 100 nm. 3. Material preparation: By weight, prepare 100 parts of chlorinated polyethylene, 20 parts of treated silica, 10 parts of main plasticizer, 5 parts of auxiliary plasticizer, 15 parts of magnesium oxide, 1.8 parts of stearic acid, and 3 parts of intercalated hydrotalcite. The chlorinated polyethylene is manufactured by Weifang Shuoyi Chemical Co., Ltd., with the brand name CM3000, a chlorine content of 36%, and a Mooney viscosity ML(1+4) of 80 at 125°C. The main plasticizer is dioctyl phthalate; The auxiliary plasticizer is chlorinated paraffin; The magnesium oxide has a particle size of 5 μm; 4. Mixing: Add the prepared chlorinated polyethylene and treated silica to the high-speed mixer and stir at 1000 rpm for 2 minutes at 80°C. Continue to add the prepared main plasticizer, auxiliary plasticizer, magnesium oxide, stearic acid, and intercalated hydrotalcite to the high-speed mixer and stir at 1000 rpm for 5 minutes at 80°C. Transfer to the open mill, set the roller temperature to 150°C, and perform open milling and thin-pass milling. Make 10 triangular rolls and produce sheets to obtain chlorinated polyethylene waterproof membrane.

[0016] Example 4 A method for preparing a weather-resistant chlorinated polyethylene waterproof membrane is as follows: 1. Preparation of intercalated hydrotalcite: 100g magnesium aluminum hydrotalcite and 1000mL water were mixed and stirred at 200rpm for 30min at room temperature. 2.4g lanthanum nitrate hexahydrate and 10g polyethylene glycol octylphenyl ether were added and stirred at 200rpm for 30min at 80℃. 10g polyethylene glycol 200 was added and stirred at 200rpm for 30min at 80℃. The mixture was cooled to room temperature and centrifuged at 3000rpm for 20min at room temperature. The precipitate was collected, washed with water, and dried to obtain intercalated hydrotalcite. The magnesium aluminum hydrotalcite has a particle size of 1000 mesh; 2. Treatment of silica: Mix 100g silica and 1200mL water, stir at 500rpm for 40min at room temperature, add 10g sodium dodecylbenzenesulfonate and 10g polyethylene glycol 400, stir at 100rpm for 3h at room temperature, centrifuge at 10000rpm for 30min at room temperature, collect the precipitate, wash with water and dry to obtain the treated silica; The silica is precipitated silica with a particle size of 100 nm. 3. Material preparation: By weight, prepare 100 parts of chlorinated polyethylene, 20 parts of treated silica, 10 parts of main plasticizer, 5 parts of auxiliary plasticizer, 15 parts of magnesium oxide, 1.8 parts of stearic acid, and 3 parts of intercalated hydrotalcite. The chlorinated polyethylene is manufactured by Weifang Shuoyi Chemical Co., Ltd., with the brand name CM3000, a chlorine content of 36%, and a Mooney viscosity ML(1+4) of 80 at 125°C. The main plasticizer is dioctyl phthalate; The auxiliary plasticizer is chlorinated paraffin; The magnesium oxide has a particle size of 5 μm; 4. Mixing: Add the prepared chlorinated polyethylene and treated silica to the high-speed mixer and stir at 1000 rpm for 2 minutes at 80°C. Continue to add the prepared main plasticizer, auxiliary plasticizer, magnesium oxide, stearic acid, and intercalated hydrotalcite to the high-speed mixer and stir at 1000 rpm for 5 minutes at 80°C. Transfer to the open mill, set the roller temperature to 150°C, and perform open milling and thin-pass milling. Make 10 triangular rolls and produce sheets to obtain chlorinated polyethylene waterproof membrane.

[0017] Comparative Example 1 Based on the preparation method of weather-resistant chlorinated polyethylene waterproof membrane in Example 1, the only difference is that step 1, preparing the intercalated hydrotalcite, is replaced with: Mix 100g of magnesium aluminum hydrotalcite with 1000mL of water and stir at 200rpm for 30min at room temperature. Add 10g of polyethylene glycol octylphenyl ether and stir at 200rpm for 30min at 80℃. Add 10g of polyethylene glycol 200 and stir at 200rpm for 30min at 80℃. Cool to room temperature and centrifuge at 3000rpm for 20min at room temperature. Take the precipitate, wash with water and dry to obtain intercalated hydrotalcite. The magnesium-aluminum hydrotalcite has a particle size of 1000 mesh.

[0018] Comparative Example 2 Based on the preparation method of weather-resistant chlorinated polyethylene waterproof membrane in Example 1, the only difference is that step 1, preparing the intercalated hydrotalcite, is replaced with: Mix 100g of magnesium aluminum hydrotalcite with 1000mL of water and stir at 200rpm for 30min at room temperature. Add 2.4g of lanthanum nitrate hexahydrate and stir at 200rpm for 30min at 80℃. Add 10g of polyethylene glycol 200 and stir at 200rpm for 30min at 80℃. Cool to room temperature and centrifuge at 3000rpm for 20min at room temperature. Take the precipitate, wash with water and dry to obtain intercalated hydrotalcite. The magnesium-aluminum hydrotalcite has a particle size of 1000 mesh.

[0019] Comparative Example 3 Based on the preparation method of weather-resistant chlorinated polyethylene waterproof membrane in Example 1, the only difference is that step 1, preparing the intercalated hydrotalcite, is replaced with: Mix 100g of magnesium aluminum hydrotalcite with 1000mL of water and stir at 200rpm for 30min at room temperature. Add 2.4g of lanthanum nitrate hexahydrate and 10g of polyethylene glycol octylphenyl ether and stir at 200rpm for 30min at 80℃. Cool to room temperature and centrifuge at 3000rpm for 20min at room temperature. Take the precipitate, wash with water and dry to obtain intercalated hydrotalcite. The magnesium-aluminum hydrotalcite has a particle size of 1000 mesh.

[0020] Comparative Example 4 Based on the preparation method of weather-resistant chlorinated polyethylene waterproof membrane in Example 1, the only difference is that step 2, treating the silica, is changed to: Mix 100g of silica and 1000mL of water, stir at 200rpm for 30min at room temperature, add 18g of sodium dodecylbenzenesulfonate, stir at 50rpm for 2h at room temperature, centrifuge at 10000rpm for 20min at room temperature, take the precipitate, wash with water and dry to obtain the treated silica. The silica is precipitated silica with a particle size of 100 nm.

[0021] Comparative Example 5 Based on the preparation method of weather-resistant chlorinated polyethylene waterproof membrane in Example 1, the only difference is that step 2, treating the silica, is changed to: Mix 100g of silica and 1000mL of water, stir at 200rpm for 30min at room temperature, add 18g of polyethylene glycol 400, stir at 50rpm for 2h at room temperature, centrifuge at 10000rpm for 20min at room temperature, take the precipitate, wash with water and dry to obtain the treated silica. The silica is precipitated silica with a particle size of 100 nm.

[0022] Application Example 1 The Mooney viscosity of the chlorinated polyethylene waterproof membranes prepared in Examples 1-4 and Comparative Examples 1-5 was tested at 165°C. The membranes were preheated for 1 minute and tested for 4 minutes. The test results are as follows:

[0023] Application Example 2 Chlorinated polyethylene waterproof membranes with a thickness of 1.5 mm were prepared according to the methods of Examples 1-4 and Comparative Examples 1-5. Then, according to the standard GB 12953-2003 Chlorinated Polyethylene Waterproof Membrane, the tensile strength, elongation at break, dimensional change rate after heat treatment (80℃×24h), low-temperature bending performance, puncture resistance, and impermeability of Examples 1-4 and Comparative Examples 1-5 were tested. During the test, 10 test samples were selected for each formulation, and the average value of the 10 test samples was taken.

[0024] The test results are as follows:

[0025] Application Example 3 The chlorinated polyethylene waterproof membranes of Examples 1-4 and Comparative Examples 1-5 were subjected to xenon lamp aging tests and hot air aging tests, and the specific methods are as follows: Xenon lamp aging test: After testing the tensile strength and elongation at break of the chlorinated polyethylene waterproof membrane test sample according to the method in Application Example 3, the chlorinated polyethylene waterproof membrane test sample was added to a xenon lamp aging test chamber. The xenon lamp aging test chamber used irradiation light of 270-800nm, and the light intensity was controlled at 500W / m. 2 The blackboard temperature of the test chamber was controlled at 63℃, the relative humidity at 50%, the water precipitation time at 18 min, and the drying time at 102 min, with each cycle lasting 2 hours, for a total test time of 250 hours. Then, the tensile strength and elongation at break of the chlorinated polyethylene waterproof membrane test samples were tested, and the decrease rate of tensile strength and the decrease rate of elongation at break were calculated. Ten test samples were selected for each formulation, and the average value of the ten test samples was taken. Hot air aging test: After testing the tensile strength and elongation at break of the chlorinated polyethylene waterproof membrane test samples according to the method in Application Example 3, the chlorinated polyethylene waterproof membrane test samples were placed in a hot air aging test chamber. The suspension spacing of the test samples was controlled to 20 mm, and the temperature of the test chamber was controlled to 100 °C. After 168 h, the tensile strength and elongation at break of the chlorinated polyethylene waterproof membrane test samples were tested, and the decrease rate of tensile strength and the decrease rate of elongation at break were calculated. Ten test samples were selected for each formulation, and the average value of the ten test samples was taken. The calculation results are as follows:

[0026] The results from Application Examples 1-3 show that adding lanthanum nitrate hexahydrate during the preparation of intercalated layered double hydroxides can improve the weather resistance of the prepared chlorinated polyethylene; adding polyethylene glycol octylphenyl ether and polyethylene glycol 200 during the preparation of intercalated layered double hydroxides can improve the weather resistance, mechanical properties, and processing properties of the prepared chlorinated polyethylene; adding sodium dodecylbenzenesulfonate and polyethylene glycol 400 during the treatment of silica can improve the weather resistance, mechanical properties, and processing properties of the prepared chlorinated polyethylene, and there is also a synergistic effect between sodium dodecylbenzenesulfonate and polyethylene glycol 400.

Claims

1. A method for preparing a weather-resistant chlorinated polyethylene waterproof membrane, characterized in that, include: Preparation of intercalated hydrotalcite, treatment of precipitated silica, material preparation, and mixing; The preparation of intercalated hydrotalcite involves mixing magnesium aluminum hydrotalcite and water, stirring at room temperature, adding lanthanum nitrate hexahydrate and polyethylene glycol octylphenyl ether, stirring at 80°C, adding polyethylene glycol 200, stirring at 80°C, cooling to room temperature, centrifuging, taking the precipitate, washing with water and drying to obtain intercalated hydrotalcite. The process for treating silica involves mixing silica and water, stirring at room temperature, adding sodium dodecylbenzenesulfonate and polyethylene glycol 400, stirring at room temperature, centrifuging, collecting the precipitate, washing it with water, and drying it to obtain the treated silica.

2. The method for preparing weather-resistant chlorinated polyethylene waterproof membrane according to claim 1, characterized in that, In the preparation of the intercalated hydrotalcite, the ratio of magnesium aluminum hydrotalcite, water, lanthanum nitrate hexahydrate, polyethylene glycol octylphenyl ether, and polyethylene glycol 200 is 100g:1000-1200mL:2.4-2.6g:10-12g:10-12g.

3. The method for preparing weather-resistant chlorinated polyethylene waterproof membrane according to claim 1, characterized in that, In the preparation of the intercalated hydrotalcite, the particle size of the magnesium aluminum hydrotalcite is 800-1200 mesh.

4. The method for preparing weather-resistant chlorinated polyethylene waterproof membrane according to claim 1, characterized in that, In the process of treating silica, the ratio of silica, water, sodium dodecylbenzenesulfonate, and polyethylene glycol 400 is 100g:1000-1200mL:9-10g:9-10g.

5. The method for preparing weather-resistant chlorinated polyethylene waterproof membrane according to claim 1, characterized in that, The silica in the process is precipitated silica with a particle size of 50-100 nm.

6. The method for preparing weather-resistant chlorinated polyethylene waterproof membrane according to claim 1, characterized in that, The materials to be prepared, by weight, are 100 parts of chlorinated polyethylene, 20-25 parts of treated silica, 10-12 parts of primary plasticizer, 5-6 parts of secondary plasticizer, 15-18 parts of magnesium oxide, 1.8-2 parts of stearic acid, and 3-3.2 parts of intercalated hydrotalcite.

7. The method for preparing weather-resistant chlorinated polyethylene waterproof membrane according to claim 6, characterized in that, In the preparation of the materials, the manufacturer of the chlorinated polyethylene is Weifang Shuoyi Chemical Co., Ltd., the brand name is CM3000, the chlorine content is 36%, and the Mooney viscosity ML(1+4) 125℃ is 80. The main plasticizer is dioctyl phthalate; The auxiliary plasticizer is chlorinated paraffin; The magnesium oxide has a particle size of 2-10 μm.

8. The method for preparing weather-resistant chlorinated polyethylene waterproof membrane according to claim 1, characterized in that, The mixture is prepared by adding chlorinated polyethylene and treated silica to a high-speed mixer, followed by a first high-speed mixing. Then, the prepared main plasticizer, auxiliary plasticizer, magnesium oxide, stearic acid, and intercalated hydrotalcite are added to the high-speed mixer, followed by a second high-speed mixing. The mixture is then subjected to open milling and thin-passing, formed into triangular sheets, and extruded into sheets to obtain chlorinated polyethylene waterproof membrane.

9. The method for preparing weather-resistant chlorinated polyethylene waterproof membrane according to claim 8, characterized in that, In the mixing process, the temperature of the first high-speed stirring is 80-82℃, the stirring speed is 1000-1200rpm, and the time is 2-3min; The second high-speed stirring was carried out at a temperature of 80-82℃, a stirring speed of 1000-1200 rpm, and a time of 5-6 minutes. The roll temperature during the initial thin pass of the mill is 150-155℃; The number of times to apply the triangular bandage is 9-11.

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