A root-resistant EPDM waterproofing membrane and a preparation method thereof

Abstract

This invention relates to the field of polymer waterproofing materials technology, and discloses a root-barrier EPDM rubber waterproofing material, comprising the following components by weight: 60-80 parts EPDM rubber, 15-25 parts polypropylene resin, 5-15 parts butyl rubber, 10-15 parts carbon black N330, 5-10 parts silica, 10-16 parts 4010 naphthenic oil, 3-8 parts composite root inhibitor, 2-5 parts vulcanization system, 1-3 parts activation system, 1.5-3 parts anti-aging system, and 0.5-2 parts processing aid. The invention also discloses a preparation method. This invention has the following beneficial technical effects: higher seam peel strength; effectively prevents the migration and loss of the root inhibitor, achieving a long-lasting root-barrier effect; stronger puncture resistance; and solves the problems of poor water tightness and insufficient low-temperature flexibility of traditional weldable EPDM roll materials.

Description

Technical Field

[0001] This invention relates to the field of polymer waterproofing materials technology, specifically to a root-resistant EPDM rubber waterproofing material and its preparation method, and particularly to a dynamically vulcanized EPDM rubber waterproofing membrane with weldable joints and root penetration resistance. Background Technology

[0002] Ethylene propylene diene monomer (EPDM) waterproofing materials have become the preferred material for high-end waterproofing projects due to their excellent weather resistance, ozone resistance, chemical corrosion resistance, and good physical and mechanical properties. Ordinary EPDM waterproofing membranes possess excellent properties such as high strength, high elongation, puncture resistance, and resistance to high and low temperatures, theoretically possessing the basic conditions for physical root barrier properties. However, existing EPDM waterproofing materials have some technical defects.

[0003] Traditional EPDM waterproof membranes typically use adhesives to bond overlapping joints, resulting in low joint strength and poor durability. These joints are easily weakened by plant roots, leading to poor root-blocking effects and leaks. Existing root-blocking waterproof materials use chemical root inhibitors, but these agents migrate and leach over time, causing their effectiveness to diminish. Furthermore, some chemical root inhibitors pose potential environmental hazards. Materials relying solely on physical root blocking often require increased thickness, raising costs and complicating construction. Ordinary EPDM waterproof materials suffer from phase separation during dynamic vulcanization. The poor compatibility between the polypropylene and rubber phases results in suboptimal tear strength and puncture resistance, failing to meet the stringent mechanical performance requirements of root-blocking materials. Current technologies for composite bonding of butyl rubber and EPDM rubber have not been effectively solved. The significant difference in vulcanization rates between the two rubbers and weak interfacial bonding limits the multi-layered composite structure design of root-blocking waterproof materials. Meanwhile, the crosslinking system is not precisely controlled, and the residual internal stress caused by rapid crosslinking seriously affects the long-term dimensional stability of the material.

[0004] CN108424584A discloses a graphene-based EPDM root-barrier waterproof membrane, which is composed of the following components and parts by weight: 80-125 parts EPDM rubber, 32-47 parts graphene nanosheets, 22-38 parts tackifying resin, 6-15 parts root inhibitor, 8-13 parts rubber softener, 2-8 parts antioxidant, and 1-4 parts crosslinking agent. Its corresponding performance still needs improvement.

[0005] Therefore, developing a EPDM rubber waterproof material that combines excellent physical and mechanical properties, weldable joints, and long-lasting root barrier function has become an urgent technical problem to be solved in this field. Summary of the Invention

[0006] This invention discloses a root-barrier EPDM rubber waterproof material. By dynamically vulcanizing EPDM with functional materials, combined with a specific process formula and processing method, its performance meets engineering design requirements. It solves the joint bonding defects of traditional products, realizes weldable lap joints and high joint peel strength, is suitable for modern buildings and waterproofing projects, and reduces the risk of water leakage caused by easily punctured joints and poor root-barrier effect in applications.

[0007] To solve the above-mentioned technical problems, the present invention provides a root-barrier EPDM rubber waterproof material, which comprises the following components by weight: 60-80 parts of EPDM rubber, 15-25 parts of polypropylene resin, 5-15 parts of butyl rubber, 10-15 parts of carbon black N330, 5-10 parts of silica, 10-16 parts of 4010 naphthenic oil, 3-8 parts of composite root inhibitor, 2-5 parts of vulcanization system, 1-3 parts of activation system, 1.5-3 parts of anti-aging system, and 0.5-2 parts of processing aid.

[0008] Furthermore, the EPDM rubber is an ethylene-propylene-nonconjugated diene terpolymer, wherein the ethylene content is 50-65 wt%, the third monomer is ethylene-idene norbornene (ENB) with a content of 4-8 wt%, and the Mooney viscosity ML(1+4) at 125°C is 40-60.

[0009] Furthermore, the polypropylene resin is homopolymer polypropylene with a melt flow rate of 2-10 g / 10min (230℃, 2.16 kg) and isotacticity ≥95%.

[0010] Furthermore, the butyl rubber is an isobutylene-isoprene copolymer with an unsaturation degree of 1.5-2.5 mol% and a Mooney viscosity (ML(1+8)) of 40-55 at 125 °C.

[0011] Furthermore, the silica is fumed silica with a specific surface area of ​​150-250 m² / g and a particle size of 10-20 nm, and its surface is modified with a silane coupling agent.

[0012] Furthermore, the composite root inhibitor is composed of a physical root inhibitor and a chemical root inhibitor in a mass ratio of 2:1, wherein the physical root inhibitor is nano-montmorillonite with a particle size of 50-100 nm and an interlayer spacing of ≥1.8 nm; and the chemical root inhibitor is 2,3,5,6-tetrachloro-4-(methylsulfonyl)pyridine.

[0013] Furthermore, the vulcanization system is a slow crosslinking system, comprising, by weight: 0.8-1.5 parts of dicumyl peroxide (DCP), 0.5-1.2 parts of triallyl isocyanurate (TAIC), 0.3-0.8 parts of sulfur, and 0.4-1.5 parts of accelerator TMTD.

[0014] Furthermore, the activation system comprises, by weight, 2-5 parts zinc oxide, 0.5-1.5 parts stearic acid, and 0.3-0.8 parts polyethylene glycol.

[0015] Furthermore, the anti-aging system comprises, by weight, 0.5-1 parts of antioxidant RD, 0.5-1 parts of antioxidant 4010NA, and 0.5-1 parts of ultraviolet absorber UV-327.

[0016] Furthermore, the processing aids include, by weight, 1-3 parts of silane coupling agent Si69, 0.5-1 parts of polyethylene wax, and 0.3-0.8 parts of zinc stearate.

[0017] This invention also provides a method for preparing the above-mentioned root-barrier EPDM rubber waterproof material, comprising the following steps: S1. Raw material pretreatment: Bake EPDM rubber and butyl rubber for 1-2 hours, then cut them into small pieces of 5-10 cm. S2. Internal mixing and blending: Add EPDM rubber and butyl rubber to an internal mixer at a rotor speed of 40-50 rpm and a temperature of 90-120 ℃ for 2-3 minutes; then add polypropylene resin and continue mixing for 3-5 minutes until the resin is completely melted; next, add silica, naphthenic oil, and silane coupling agent and mix for 5-8 minutes; finally, add the activation system, antioxidant system, composite root inhibitor, and processing aid, and mix for 3-5 minutes, with the discharge temperature controlled at 140-150 ℃. S3. Open mill sheeting: After the internally mixed rubber compound is filtered, it is fed into the open mill, and the vulcanization system is added. The roller temperature is controlled at 55-65 ℃, the roller gap is 2-3 mm, and the thin pass is 3-5 times. Then the sheet is cooled. S4. Dynamic vulcanization: The cooled rubber compound is fed into a single-screw extruder for dynamic vulcanization. The temperatures of each section are set as follows: feeding section 145-155 ℃, plasticizing section 160-170 ℃, vulcanization section 1 170-180 ℃, vulcanization section 2 175-185 ℃, homogenization section 170-180 ℃, die head temperature 165-175 ℃, screw speed 40-70 rpm, feeding rate controlled at 80-120 kg / h, material residence time 2.5-4 minutes, extrusion pressure controlled at 12-18 MPa, and die head pressure controlled at 8-12 MPa. The vulcanization reaction is completed during the extrusion process. S5. Calendering: The dynamically vulcanized rubber compound is calendered into rolls with a thickness of 1.2-2.0 mm using a three-roll calender, with the calendering temperature controlled at 80-100 ℃. S6. Cooling and winding: The calendered roll is cooled to room temperature by cooling rollers and then wound into a finished product.

[0018] Furthermore, in step S2, the silica is added in batches. First, 60% of the silica is added and mixed for 3 minutes, then the remaining 40% of the silica is added and mixed for 5 minutes to ensure uniform dispersion of the silica.

[0019] Furthermore, in step S4, the dynamic vulcanization process adopts segmented temperature-controlled vulcanization technology. The degree of vulcanization is precisely controlled by adjusting the screw speed and temperature distribution, and the gelation rate is controlled at 85-90%.

[0020] Compared with the prior art, the present invention has the following beneficial technical effects: 1. Weldable joint technology: This invention achieves uniform blending of rubber and polypropylene phases through dynamic vulcanization process. The material surface has good thermoplasticity and can be treated with hot air welding. The joint peel strength can reach more than 1.5 N / mm, which is far higher than traditional adhesive bonding methods. This fundamentally solves the problem of weak joints and ensures the integrity of the root barrier system.

[0021] 2. Composite root barrier technology: The composite root barrier technology combines physical and chemical root barrier. The layered structure of nano-montmorillonite not only provides a physical barrier but also adsorbs chemical root barrier agents, effectively preventing the migration and loss of root barrier agents and achieving a long-lasting root barrier effect.

[0022] 3. Nanoscale dispersion technology of silica: Through stepwise feeding process and in-situ modification with silane coupling agent, the nanoscale uniform dispersion of silica in rubber matrix is ​​achieved. The filler-rubber interaction is enhanced, the tear strength of the material can reach more than 25 N / mm, the tensile strength can reach more than 7.5 MPa, and the elongation at break can reach more than 450%, which significantly improves the puncture resistance of the material.

[0023] 4. Ternary Blend Dynamic Vulcanization System: For the first time, butyl rubber is introduced into the weldable EPDM / PP dynamic vulcanization system. By controlling the matching of vulcanization rates (EPDM vulcanization rate is fast, butyl rubber is slow), good co-vulcanization of the two phases is achieved, solving the problems of poor water tightness and insufficient low-temperature flexibility of traditional weldable EPDM rolls. Attached Figure Description

[0024] Figure 1 This is a process flowchart of the preparation method of the present invention. Detailed Implementation

[0025] Production and preparation process: The root-barrier EPDM rubber waterproof material of this embodiment has the following formula by weight: 70 parts of EPDM rubber (Dow Chemical 4770R, ethylene content 56wt%, ENB content 5.5wt%, Mooney viscosity 50), 20 parts of polypropylene resin (Yanshan Petrochemical 1300, melt flow rate 3.0 g / 10min), 10 parts of butyl rubber (Exxon 268, unsaturation 2.0 mol%, Mooney viscosity 47), 30 parts of fumed silica (Cabot LM-150, specific surface area 150 m² / g), 12 parts of 4010 naphthenic oil (Karamay 4010), 4 parts of nano-montmorillonite (Zhejiang Fenghong DK-2, interlayer spacing 2.1 nm), 2 parts of chemical root inhibitor (2,3,5,6-tetrachloro-4-(methylsulfonyl)pyridine), 1.0 part of DCP, 0.8 parts of TAIC, 0.5 parts of sulfur, and TMTD accelerator. 0.7 parts, zinc oxide 3 parts, stearic acid 1.0 part, polyethylene glycol 0.5 parts, antioxidant RD 0.8 parts, antioxidant 4010NA 0.7 parts, ultraviolet absorber UV-327 0.6 parts, silane coupling agent Si69 2 parts, polyethylene wax 0.8 parts, zinc stearate 0.5 parts.

[0026] The preparation method is as follows: S1. Raw material pretreatment: Bake EPDM rubber and butyl rubber for 1 hour, then cut them into small pieces of about 8cm. S2. Internal mixing and blending: Add EPDM rubber and butyl rubber to an internal mixer at a rotor speed of 45 rpm and a temperature of 85 ℃ for 2.5 minutes; then add polypropylene resin and continue mixing for 4 minutes until the resin is completely melted; next, add 18 parts of silica, all of 4010 naphthenic oil, and all of silane coupling agent Si69, and mix for 3 minutes; then add the remaining 12 parts of silica and mix for 6 minutes; finally, add zinc oxide, stearic acid, polyethylene glycol, antioxidant, composite root inhibitor, polyethylene wax, and zinc stearate, and mix for 4 minutes, with the discharge temperature controlled at 145 ℃. S3. Open milling and sheeting: The internally mixed rubber compound is fed into the open mill, the roller temperature is controlled at 60 ℃, the roller gap is 2.5 mm, and it is passed through the mill 4 times. Then the sheet is cooled to room temperature and left to stand for 8 hours. S4. Dynamic Vulcanization: The cooled rubber compound is fed into a single-screw extruder for dynamic vulcanization. The extruder uses a barrier-type pin screw with a length-to-diameter ratio of 25:1. The temperatures of each section are set as follows: feeding section 150 ℃, plasticizing section 165 ℃, vulcanization section 1 175 ℃, vulcanization section 2 180 ℃, homogenization section 175 ℃, and die head temperature 170 ℃. The screw speed is 60 rpm, the feeding rate is 100 kg / h, the material residence time is about 3 minutes, the extrusion pressure is controlled at 15 MPa, and the die head pressure is controlled at 10 MPa. The vulcanization reaction is completed during the extrusion process, and the gelation rate is controlled at 88%. S5. Calendering: The dynamically vulcanized rubber compound is calendered into rolls with a thickness of 1.5 mm using a three-roll calender. The calendering temperature is controlled at 90 ℃ and the linear speed is 5 m / min. S6. Cooling and winding: The calendered roll is cooled to room temperature by cooling rollers and then wound into finished products, each roll being 20 m long and 1 m wide.

[0027] The applicant conducted performance testing, and the results are shown in the table below:

[0028] On-site construction process: This invention is applicable to root-penetration resistant waterproofing projects such as green roofs, roofs of large public buildings, and underground engineering slabs. The core technology used is hot air welding joint technology, and the construction process is as follows.

[0029] (1) Construction preparation: Materials: 1.2-2.0 mm thick roll material, welding rods of the same material, butyl sealant, metal pressure strip, 0.4 mm thick polyethylene isolation film Equipment: automatic hot air welding machine, handheld welding gun, weld gas filling tester, pressure roller, cutter Base requirements: flat and firm, moisture content ≤9%; internal and external corners are rounded with R≥50 mm; no sand, hollow, or oil stains.

[0030] (2) Core process flow: Base treatment → Apply base treatment agent (0.2-0.3kg / m²) → Construction of additional layers such as corners / pipes (width ≥500 mm) → Roll positioning and laying → Hot air welding → Weld inspection → Node sealing → End fixing → Water tightness test → Construction of protective layer / planting layer.

[0031] (3) Key construction points:

[0032] Roll material installation: slope <3% parallel to the ridge, slope >3% perpendicular to the ridge; long side overlap ≥80 mm, short side overlap ≥100 mm; allow 0.5%-1% expansion allowance.

[0033] Hot air welding: Automatic welding: temperature 380-420 ℃, speed 1.5-2.5 m / min, pressure 0.2-0.3 MPa; Hand-held welding: Temperature 350-390 ℃, short side double pass welding (spacing ≥30 mm).

[0034] Weld inspection: Visual inspection reveals no missing welds / false welds; pressurize to 0.2 MPa, hold pressure for 15 minutes, and the pressure drop is ≤0.01 MPa to be considered acceptable.

[0035] Finishing treatment: fix with metal strips (spacing ≤ 600 mm), seal with butyl sealant; flashing height ≥ 250 mm.

[0036] (4) Acceptance and Precautions:

[0037] Water tightness test: water storage ≥20 mm, no leakage on roof for 24 hours and underground works for 72 hours; Environmental requirements: Construction temperature 5-35 ℃, operation is strictly prohibited in rainy weather or winds of level 5 or above; Finished product protection: Wear soft-soled shoes to avoid sharp objects puncturing the roll material; repair damaged areas by welding with the same type of roll material.

[0038] The above embodiments are merely preferred technical solutions of the present invention and should not be considered as limitations on the present invention. The scope of protection of the present invention should be limited to the technical solutions described in the claims, including equivalent substitutions of the technical features described in the claims. That is, equivalent substitutions and improvements within this scope are also within the scope of protection of the present invention.

Claims

1. A root barrier EPDM waterproofing material, characterized by, By weight, it includes the following components: 60-80 parts of EPDM rubber, 15-25 parts of polypropylene resin, 5-15 parts of butyl rubber, 10-15 parts of carbon black N330, 5-10 parts of silica, 10-16 parts of 4010 naphthenic oil, 3-8 parts of composite root inhibitor, 2-5 parts of vulcanization system, 1-3 parts of activation system, 1.5-3 parts of anti-aging system, and 0.5-2 parts of processing aids.

2. The root barrier EPDM waterproofing material according to claim 1, characterized in that, The EPDM rubber is an ethylene-propylene-nonconjugated diene terpolymer, wherein: the ethylene content is 50-65wt%, the third monomer is ethylene-bis(norbornene) with a content of 4-8wt%, and the Mooney viscosity ML(1+4) at 125℃ is 40-60.

3. The root barrier EPDM waterproofing material according to claim 2, characterized in that, The polypropylene resin is homopolymer polypropylene with a melt flow rate of 2-10 g / 10min (230 ℃, 2.16 kg) and isotacticity ≥95%.

4. The root-barrier EPDM rubber waterproof material according to claim 3, characterized in that, The butyl rubber is an isobutylene-isoprene copolymer with an unsaturation of 1.5-2.5 mol% and a Mooney viscosity (ML(1+8)) of 40-55 at 125 °C.

5. The root-barrier EPDM rubber waterproof material according to claim 4, characterized in that, The silica is fumed silica with a specific surface area of ​​150-250 m² / g and a particle size of 10-20 nm, and its surface is modified with a silane coupling agent.

6. The root-barrier EPDM rubber waterproof material according to claim 5, characterized in that, The composite root inhibitor is composed of a physical root inhibitor and a chemical root inhibitor in a mass ratio of 2:

1. The physical root inhibitor is nano-montmorillonite with a particle size of 50-100 nm and an interlayer spacing of ≥1.8 nm. The chemical root inhibitor is 2,3,5,6-tetrachloro-4-(methylsulfonyl)pyridine.

7. The root-barrier EPDM rubber waterproof material according to claim 6, characterized in that, The vulcanization system is a slow crosslinking system, comprising, by weight: 0.8-1.5 parts dicumyl peroxide, 0.5-1.2 parts triallyl isocyanurate, 0.3-0.8 parts sulfur, and 0.4-1.5 parts accelerator TMTD.

8. The root-barrier EPDM rubber waterproof material according to claim 7, characterized in that, The activation system comprises, by weight, 2-5 parts zinc oxide, 0.5-1.5 parts stearic acid, and 0.3-0.8 parts polyethylene glycol.

9. A root-barrier EPDM rubber waterproof material according to claim 8, characterized in that, The anti-aging system comprises, by weight, 0.5-1 parts of antioxidant RD, 0.5-1 parts of antioxidant 4010NA, and 0.5-1 parts of ultraviolet absorber UV-327; the processing aids comprise, by weight, 1-3 parts of silane coupling agent Si69, 0.5-1 parts of polyethylene wax, and 0.3-0.8 parts of zinc stearate.

10. A method for preparing the root-barrier EPDM rubber waterproof material according to any one of claims 1 to 9, characterized in that... This includes the following steps: S1. Raw material pretreatment: Bake EPDM rubber and butyl rubber for 1-2 hours, then cut them into small pieces of 5-10cm. S2. Internal mixing and blending: Add EPDM rubber and butyl rubber to an internal mixer at a rotor speed of 40-50 rpm and a temperature of 90-120 ℃ for 2-3 minutes; then add polypropylene resin and continue mixing for 3-5 minutes until the resin is completely melted; next, add silica, naphthenic oil, and silane coupling agent and mix for 5-8 minutes; finally, add the activation system, antioxidant system, composite root inhibitor, and processing aid, and mix for 3-5 minutes, with the discharge temperature controlled at 140-150 ℃. S3. Open mill sheeting: After the internally mixed rubber compound is filtered, it is fed into the open mill, and the vulcanization system is added. The roller temperature is controlled at 55-65 ℃, the roller gap is 2-3 mm, and the thin pass is 3-5 times. Then the sheet is cooled. S4. Dynamic vulcanization: The cooled rubber compound is fed into a single-screw extruder for dynamic vulcanization. The temperatures of each section are set as follows: feeding section 145-155 ℃, plasticizing section 160-170 ℃, vulcanization section 1 170-180 ℃, vulcanization section 2 175-185 ℃, homogenization section 170-180 ℃, die head temperature 165-175 ℃, screw speed 40-70 rpm, feeding rate controlled at 80-120 kg / h, material residence time 2.5-4 minutes, extrusion pressure controlled at 12-18 MPa, and die head pressure controlled at 8-12 MPa. The vulcanization reaction is completed during the extrusion process. S5. Calendering: The dynamically vulcanized rubber compound is calendered into rolls with a thickness of 1.2-2.0 mm using a three-roll calender, with the calendering temperature controlled at 80-100 ℃. S6. Cooling and winding: The calendered roll is cooled to room temperature by cooling rollers and then wound into a finished product.

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