Preparation process of puncture-resistant flame-retardant polyethylene waterproof coiled material, waterproof coiled material, external magnetic field enrichment device and application

Abstract

The application relates to the field of waterproof coiled materials, and particularly discloses a preparation process of a puncture-resistant and flame-retardant polyethylene waterproof coiled material, the waterproof coiled material, an external magnetic field enrichment device and application, and the preparation process comprises the following steps: (1) weighing raw materials, uniformly stirring the raw material components to obtain a mixture; (2) performing extrusion granulation on the mixture to obtain a master batch; (3) performing extrusion molding on the master batch, and applying an external magnetic field to the extruded coiled material, so that shielding agents are enriched on one side of the extruded coiled material, and an uncrosslinked waterproof coiled material is obtained; and (4) performing local ultraviolet light irradiation crosslinking on the side of the uncrosslinked waterproof coiled material where the shielding agents are enriched, and obtaining a waterproof coiled material with an uncrosslinked splicing end. The application can overcome the problems that the puncture-resistant layer of the existing waterproof coiled material cannot be hot welded or is prone to delamination and has low joint peeling strength due to compatibility problems.

Description

Technical Field

[0001] This application relates to the field of waterproof membranes, and more specifically, it relates to a preparation process of a puncture-resistant and flame-retardant polyethylene waterproof membrane, the waterproof membrane itself, an external magnetic field enrichment device, and its application. Background Technology

[0002] Polyethylene waterproof membrane is a very common flexible waterproof material that is currently used in numerous projects. However, the waterproof performance of current polyethylene waterproof membranes after continuous application requires a high degree of integrity, as local damage can easily lead to internal water seepage. Furthermore, polyethylene itself has low hardness and poor puncture resistance. The imperfections of perfectly flat construction sites and the impact of plant root penetration further necessitate an increasing demand for improved puncture resistance in polyethylene membranes.

[0003] Because the substrate for rolled waterproofing membranes often contains sharp objects and requires root protection, the puncture resistance of these membranes is increasingly important. A common practice is to attach a layer of plastic material with better strength, hardness, and puncture resistance than the substrate to the surface of the membrane. Chinese patent CN201720731471.9 discloses a PVC root-puncture resistant waterproof membrane, which adds a polystyrene puncture-resistant layer to the surface of the PVC membrane. Chinese patent CN201621257037.3 discloses a TPO self-adhesive composite root-puncture resistant waterproof membrane, which adds a puncture-resistant layer formed of TPO material.

[0004] However, the puncture-resistant layer is usually made of different types of plastics, which may lead to problems such as inability to heat weld or compatibility issues causing delamination and low seam peel strength. Summary of the Invention

[0005] In order to overcome the problems of existing waterproof membranes having puncture-resistant layers that cannot be heat-welded or are prone to delamination and low joint peel strength due to compatibility issues, this application provides a preparation process for a puncture-resistant flame-retardant polyethylene waterproof membrane, the waterproof membrane itself, an external magnetic field enrichment device, and its application.

[0006] In a first aspect, this application provides a process for preparing a puncture-resistant, flame-retardant polyethylene waterproof membrane, employing the following technical solution:

[0007] A process for preparing a puncture-resistant, flame-retardant polyethylene waterproof membrane includes the following steps:

[0008] (1) Weigh the raw materials and stir the raw material components evenly to obtain a mixture; the raw materials of the waterproof membrane are composed of resin, crosslinking agent, photoinitiator and shielding agent, and the shielding agent is a charged ultraviolet shielding agent;

[0009] (2) The mixture is extruded and granulated to obtain masterbatch;

[0010] (3) The masterbatch is extruded and an external magnetic field is applied to the extruded roll material to enrich the shielding agent on one side of the extruded roll material, thus obtaining an uncrosslinked waterproof roll material.

[0011] (4) Local ultraviolet light irradiation is applied to the side of the uncrosslinked waterproof membrane enriched with shielding agent to crosslink it, so as to obtain an uncrosslinked waterproof membrane at the splicing end.

[0012] By adopting the above technical solution, on the one hand, this application can form a cross-linked layer on the surface of the waterproof membrane through ultraviolet irradiation cross-linking, which can effectively improve the flexibility, surface puncture resistance, and mechanical properties of the membrane. However, because the polyethylene forms a cross-chain network structure after cross-linking, the material loses its thermoplasticity, affecting the subsequent hot welding performance. Furthermore, the elongation at break of the cross-linked waterproof membrane decreases significantly, affecting its flexibility. Therefore, this application adds a charged ultraviolet shielding agent to the raw materials of the waterproof membrane, and combines this with the application of an external magnetic field to the uncross-linked waterproof membrane. This allows the ultraviolet shielding agent to accumulate on one side of the waterproof membrane. During the local cross-linking process of the waterproof membrane under ultraviolet light, only a cross-linked layer forms on the surface. Due to the shielding effect of the ultraviolet shielding agent, deeper cross-linking is prevented, ultimately resulting in a partially cross-linked waterproof membrane. This not only improves the puncture resistance of the membrane, but also allows for good hot welding performance when splicing the uncross-linked end walls later. The overall waterproof membrane also exhibits good flexibility. Furthermore, after cross-linking on the surface of the waterproof membrane, the flame retardant properties of the membrane surface can be improved due to the reduction of carbon-carbon double bonds within the membrane.

[0013] Furthermore, the charged ultraviolet shielding agent includes titanium dioxide.

[0014] Further, in step (2), the extrusion temperature for extrusion granulation is 150-210℃. In step (3), the extrusion temperature for extrusion molding is 180-220℃, and the extrusion molding speed is 0.5-5m / min.

[0015] Furthermore, in step (3), the processing temperature during the application of the magnetic field is 190-225℃. In step (3), the strength of the external magnetic field is 10-50 A / m, and the length of the external magnetic field is 0.5-1m.

[0016] Furthermore, in step (4), the ultraviolet crosslinking temperature is 70-80℃ and the time is 10-60s. In step (4), an ultraviolet shielding plate is used to cover the non-crosslinked areas of the uncrosslinked waterproof membrane.

[0017] Furthermore, the raw materials of the waterproof membrane include the following components by weight: 54-95 parts polyethylene, 1-20 parts inorganic filler, 1-10 parts flame retardant, 1-2 parts crosslinking agent, 0.5-2 parts photoinitiator, 1-10 parts shielding agent, and 0.5-2 parts anti-aging agent.

[0018] Furthermore, the polyethylene is one or more of linear low-density polyethylene, low-density polyethylene, high-density polyethylene, and metallocene polyethylene.

[0019] The co-crosslinking agent includes, but is not limited to, one or more of the following: trimethylolpropane triacrylate (TMPTA), trimethylolpropane trimethacrylate (TMPTAMA), trimethylolpropane diallyl ether, ethylene glycol diacrylate (EGDA), ethylene glycol dimethacrylate (EGDMA), N,N′-p-phenylbismaleimide (PDM), zinc diacrylate, zinc dimethacrylate, triallyl cyanurate (TAC), and triallyl isocyanurate (TAIC).

[0020] The photoinitiator includes, but is not limited to, one or more of the following: benzophenone derivatives, thioxanthone derivatives, alkylaryl ketone derivatives and benzyl derivatives, benzoin and its derivatives, benzoyl derivatives, alkylphenyl ketones, acylphosphide oxides, aryl iodonium salts, and cumeneferric hexafluorophosphate.

[0021] The inorganic filler includes, but is not limited to, one or more of the following: calcium carbonate powder, talc powder, clay powder, attapulgite clay powder, barium sulfate powder, talc powder, and wollastonite powder.

[0022] The flame retardant mentioned therein includes, but is not limited to, one or more of phosphorus-based flame retardants, inorganic hydroxide flame retardants, and nitrogen-containing flame retardants, as well as mixtures thereof.

[0023] The anti-aging agents mentioned therein include, but are not limited to, one or more of hindered phenolic anti-aging agents, hindered amine anti-aging agents, phosphite anti-aging agents, and thioester anti-aging agents, or mixtures thereof.

[0024] Secondly, this application provides a waterproof membrane prepared according to the above-mentioned puncture-resistant polyethylene waterproof membrane preparation process, comprising an uncrosslinked polyethylene layer and a crosslinked polyethylene layer located partially on one side of the uncrosslinked polyethylene layer.

[0025] Thirdly, this application provides an external magnetic field enrichment device for the preparation process of the aforementioned puncture-resistant polyethylene waterproof membrane, comprising an upper electromagnetic device and a lower electromagnetic device mounted on the forming die of an extruder, wherein the upper electromagnetic device and the lower electromagnetic device are arranged opposite to each other. By adopting the above technical solution, this external magnetic field enrichment device can conveniently apply an external magnetic field to the membrane during the extrusion process, and has a simple structure and is easy to operate.

[0026] Fourthly, this application provides an application of a puncture-resistant, flame-retardant polyethylene waterproof membrane.

[0027] In summary, this application has the following beneficial effects:

[0028] 1. This application achieves the enrichment of ultraviolet shielding agent on the surface of the waterproof membrane by irradiating specific areas with ultraviolet light and then comprehensively controlling the amount of crosslinking agent, photoinitiator, shielding agent, and ultraviolet irradiation time through the combined action of an external magnetic field and the Lorentz force of the charged ultraviolet shielding agent. This enables control over the thickness and degree of crosslinking of the crosslinked layer on the surface of the membrane, thus meeting the requirements for membrane flexibility, surface puncture resistance, and mechanical strength under different application scenarios.

[0029] 2. The waterproof membrane in this application is cross-linked only on the surface and not on the end walls, which not only gives the waterproof membrane good puncture resistance, but also good flexibility and hot welding performance; at the same time, the preparation process is very simple. Attached Figure Description

[0030] Figure 1 This is a structural schematic diagram of the puncture-resistant, flame-retardant polyethylene waterproof membrane of this application.

[0031] Figure 2 This is a schematic diagram of the structure of the external magnetic field enrichment device in the embodiments of this application.

[0032] Figure 3 This is a schematic diagram illustrating the principle of how an external magnetic field acts on a shielding agent.

[0033] Figure 4 This is a schematic diagram of the ultraviolet crosslinking process.

[0034] Explanation of reference numerals in the attached drawings: 1. Uncrosslinked polyethylene layer; 2. Crosslinked polyethylene layer; 3. Upper electromagnetic device; 4. Lower electromagnetic device; 5. Molding mold; 6. Ultraviolet lamp; 61. Irradiation area; 7. Roll material; 8. Ultraviolet shielding plate; 9. Digitally controlled regulated power supply. Detailed Implementation

[0035] The present application will be further described in detail below with reference to the accompanying drawings and embodiments.

[0036] Example

[0037] The embodiments of this application provide a process for preparing a puncture-resistant, flame-retardant polyethylene waterproof membrane, including the following steps:

[0038] (1) The raw materials of the waterproof membrane include the following components by weight: 54-95 parts polyethylene, 1-20 parts inorganic filler, 1-10 parts flame retardant, 1-2 parts crosslinking agent, 0.5-2 parts photoinitiator, 1-10 parts shielding agent and 0.5-2 parts anti-aging agent.

[0039] The polyethylene used is a mixture of one or more of linear low-density polyethylene, low-density polyethylene, high-density polyethylene, and metallocene polyethylene. In this embodiment, low-density polyethylene LD150 and metallocene polyethylene 1018ma are specifically used. The charged ultraviolet shielding agent includes titanium dioxide.

[0040] The crosslinking agent includes, but is not limited to, one or more mixtures of trimethylolpropane triacrylate (TMPTA), trimethylolpropane trimethacrylate (TMPTAMA), diallyl trimethylolpropane ether, ethylene glycol diacrylate (EGDA), ethylene glycol dimethacrylate (EGDMA), N,N′-p-phenylbismaleimide (PDM), zinc diacrylate, zinc dimethacrylate, triallyl cyanurate (TAC), and triallyl isocyanurate (TAIC). In this embodiment, triallyl isocyanurate is specifically used.

[0041] Photoinitiators include, but are not limited to, one or more of the following: benzophenone derivatives, thioxanthone derivatives, alkylaryl ketone derivatives and benzyl derivatives, benzoin and its derivatives, benzoyl derivatives, alkylphenyl ketones, acylphosphide oxides, aryliodonium salts, and cumeneferric hexafluorophosphate. In this embodiment, benzoin dimethyl ether and benzoin are specifically used.

[0042] Inorganic fillers include, but are not limited to, one or more of the following: calcium carbonate powder, talc powder, clay powder, attapulgite clay powder, barium sulfate powder, talc powder, and wollastonite powder. In this embodiment, calcium carbonate powder is specifically used.

[0043] The flame retardants include, but are not limited to, one or more mixtures of phosphorus-based flame retardants, inorganic hydroxide flame retardants, and nitrogen-containing flame retardants. In this embodiment, magnesium hydroxide is specifically used.

[0044] The anti-aging agents include, but are not limited to, one or more mixtures of hindered phenolic anti-aging agents, hindered amine anti-aging agents, phosphite anti-aging agents, and thioester anti-aging agents. In this embodiment, antioxidant 1010 is specifically used.

[0045] Weigh the raw materials: Mix the raw material components evenly to obtain a mixture.

[0046] (2) The mixture is extruded and granulated at an extrusion temperature of 150-210℃ to obtain masterbatch.

[0047] (3) Add the granulated polyethylene roll masterbatch into the extrusion equipment for extrusion molding. The extrusion temperature is 180-220℃. Then, at the extruder outlet, apply an external magnetic field to the extruded roll using an external magnetic field device. The strength of the external magnetic field is 10-50A / m, the length of the external magnetic field is 0.5-1m, the processing temperature during the application of the magnetic field is 190-225℃, and the direction of the magnetic field is perpendicular to the extruded roll, so that the shielding agent is enriched on one side of the extruded roll, and an uncrosslinked waterproof roll is obtained.

[0048] (4) Using a UV shielding plate to block the non-crosslinked areas of the uncrosslinked waterproof membrane, the side of the uncrosslinked waterproof membrane enriched with shielding agent is locally irradiated with UV light for crosslinking, resulting in an uncrosslinked waterproof membrane at the splicing end. The UV crosslinking temperature is 70-80℃, and the time is 10-60s. A schematic diagram of the resulting waterproof membrane structure is shown below. Figure 1 As shown, it includes an uncrosslinked polyethylene layer 1 and a crosslinked polyethylene layer 2. The crosslinked polyethylene layer 2 is located above the uncrosslinked polyethylene layer 1, and the portion of the uncrosslinked polyethylene layer 1 that is located above and adjacent to the crosslinked polyethylene layer 2 is the splicing end.

[0049] For step (3), the structure of the external magnetic field device is as follows: Figure 2 As shown, it consists of an upper electromagnetic device 3 installed above the forming die 5 at the extruder outlet, and a lower electromagnetic device 4 installed below it, with the upper electromagnetic device 3 and lower electromagnetic device 4 facing each other vertically. A digitally controlled regulated power supply 9 is connected between the upper electromagnetic device 3 and the lower electromagnetic device 4 to regulate their operation. Meanwhile, Figure 2 The arrow in the image represents the direction of the magnetic field, which is perpendicular to the roll material 7.

[0050] In step (3), the principle of the effect of the external magnetic field on the shielding agent is as follows: Figure 3 As shown, under the action of the upper electromagnetic device 3 and the lower electromagnetic device 4, a vertical magnetic field is formed inside the forming mold 5. Along the extrusion direction of the roll 7, the shielding agent particles gradually accumulate to one side of the roll 7. The horizontal arrow in the figure indicates the extrusion direction of the roll 7.

[0051] In step (4), the installation method of the ultraviolet shielding plate 8 is as follows: Figure 4 As shown, the ultraviolet shielding plate 8 is installed on one side of the width direction of the roll material 7, and then under the irradiation of the ultraviolet lamp 6, the irradiated area 61 formed acts on the roll material 7 to form an uncrosslinked polyethylene layer 1 and a crosslinked polyethylene layer 2.

[0052] The following is an illustration through specific examples.

[0053] Example 1

[0054] Example 1 provides a process for preparing a puncture-resistant, flame-retardant polyethylene waterproof membrane, comprising the following steps:

[0055] (1) Weigh 76 parts of low-density polyethylene LD150, 10 parts of calcium carbonate, 5 parts of magnesium hydroxide, 1 part of triallyl isocyanurate, 2 parts of benzoin dimethyl ether, 5 parts of titanium dioxide and 1 part of antioxidant 1010; mix them at high speed to obtain a mixture.

[0056] (2) The mixture is added to a twin-screw extruder for extrusion granulation at an extrusion temperature of 200°C to obtain polyethylene roll masterbatch.

[0057] (3) The granulated polyethylene roll masterbatch is added to a single screw roll extrusion equipment for extrusion molding. The extrusion temperature is 180℃. Then, at the outlet of the extruder, an external magnetic field is applied to the extruded roll using an external magnetic field device. The strength of the external magnetic field is 20A / m, the length of the external magnetic field is 0.5m, and the processing temperature during the application of the magnetic field is 190℃ to obtain uncrosslinked polyethylene roll.

[0058] (4) Place a UV shielding plate on one side of the width direction of the uncrosslinked polyethylene roll to block it, and then use a UV crosslinking device to irradiate the uncrosslinked polyethylene roll with UV light at a temperature of 80°C and an irradiation crosslinking time of 10s to obtain a waterproof roll with uncrosslinked splicing ends.

[0059] Example 2

[0060] Example 2 provides a process for preparing a puncture-resistant, flame-retardant polyethylene waterproof membrane, comprising the following steps:

[0061] (1) Weigh 56 parts of low-density polyethylene LD150, 20 parts of calcium carbonate, 10 parts of magnesium hydroxide, 1 part of triallyl isocyanurate, 2 parts of benzoin dimethyl ether, 10 parts of titanium dioxide and 1 part of antioxidant 1010; stir at high speed to mix evenly and obtain a mixture.

[0062] (2) The mixture is added to a twin-screw extruder for extrusion granulation at an extrusion temperature of 200°C to obtain polyethylene roll masterbatch.

[0063] (3) The granulated polyethylene roll masterbatch is added to a single screw roll extrusion equipment for extrusion molding. The extrusion temperature is 180℃. Then, at the outlet of the extruder, an external magnetic field is applied to the extruded roll using an external magnetic field device. The strength of the external magnetic field is 20A / m, the length of the external magnetic field is 0.5m, and the processing temperature during the application of the magnetic field is 190℃ to obtain uncrosslinked polyethylene roll.

[0064] (4) Place a UV shielding plate on one side of the width direction of the uncrosslinked polyethylene roll to block it, and then use a UV crosslinking device to irradiate the uncrosslinked polyethylene roll with UV light at a temperature of 80°C and an irradiation crosslinking time of 10s to obtain a waterproof roll with uncrosslinked splicing ends.

[0065] Example 3

[0066] Example 3 provides a process for preparing a puncture-resistant, flame-retardant polyethylene waterproof membrane, including the following steps:

[0067] (1) Weigh 93 parts of low-density polyethylene LD150, 1 part of calcium carbonate, 1 part of magnesium hydroxide, 1 part of triallyl isocyanurate, 2 parts of benzoin, 1 part of titanium dioxide and 1 part of antioxidant 1010; stir at high speed to mix evenly and obtain a mixture.

[0068] (2) The mixture is added to a twin-screw extruder for extrusion granulation at an extrusion temperature of 200°C to obtain polyethylene roll masterbatch.

[0069] (3) The granulated polyethylene roll masterbatch is added to a single screw roll extrusion equipment for extrusion molding. The extrusion temperature is 180℃. Then, at the outlet of the extruder, an external magnetic field is applied to the extruded roll using an external magnetic field device. The strength of the external magnetic field is 20A / m, the length of the external magnetic field is 0.5m, and the processing temperature during the application of the magnetic field is 190℃ to obtain uncrosslinked polyethylene roll.

[0070] (4) Place a UV shielding plate on one side of the width direction of the uncrosslinked polyethylene roll to block it, and then use a UV crosslinking device to irradiate the uncrosslinked polyethylene roll with UV light at a temperature of 80°C and an irradiation crosslinking time of 10s to obtain a waterproof roll with uncrosslinked splicing ends.

[0071] Example 4

[0072] Example 4 provides a process for preparing a puncture-resistant, flame-retardant polyethylene waterproof membrane, comprising the following steps:

[0073] (1) Weigh 96 parts of metallocene polyethylene 1018MA, 1 part of calcium carbonate, 1 part of magnesium hydroxide, 1 part of triallyl isocyanurate, 0.5 parts of benzoin dimethyl ether, 1 part of titanium dioxide and 0.5 parts of antioxidant 1010; stir at high speed to mix well to obtain a mixture.

[0074] (2) The mixture is added to a twin-screw extruder for extrusion granulation at an extrusion temperature of 200°C to obtain polyethylene roll masterbatch.

[0075] (3) The granulated polyethylene roll masterbatch is added to a single screw roll extrusion equipment for extrusion molding. The extrusion temperature is 180℃. Then, at the outlet of the extruder, an external magnetic field is applied to the extruded roll using an external magnetic field device. The strength of the external magnetic field is 20A / m, the length of the external magnetic field is 0.5m, and the processing temperature during the application of the magnetic field is 190℃ to obtain uncrosslinked polyethylene roll.

[0076] (4) Place a UV shielding plate on one side of the width direction of the uncrosslinked polyethylene roll to block it, and then use a UV crosslinking device to irradiate the uncrosslinked polyethylene roll with UV light at a temperature of 80°C and an irradiation crosslinking time of 10s to obtain a waterproof roll with uncrosslinked splicing ends.

[0077] Example 5

[0078] Example 5 provides a process for preparing a puncture-resistant, flame-retardant polyethylene waterproof membrane, comprising the following steps:

[0079] (1) Weigh 54 parts of metallocene polyethylene 1018MA, 20 parts of calcium carbonate, 10 parts of magnesium hydroxide, 2 parts of triallyl isocyanurate, 2 parts of benzoin dimethyl ether, 10 parts of titanium dioxide and 2 parts of antioxidant 1010; stir at high speed to mix evenly to obtain a mixture.

[0080] (2) The mixture is added to a twin-screw extruder for extrusion granulation at an extrusion temperature of 200°C to obtain polyethylene roll masterbatch.

[0081] (3) The granulated polyethylene roll masterbatch is added to a single screw roll extrusion equipment for extrusion molding. The extrusion temperature is 180℃. Then, at the outlet of the extruder, an external magnetic field is applied to the extruded roll using an external magnetic field device. The strength of the external magnetic field is 20A / m, the length of the external magnetic field is 0.5m, and the processing temperature during the application of the magnetic field is 190℃ to obtain uncrosslinked polyethylene roll.

[0082] (4) Place a UV shielding plate on one side of the width direction of the uncrosslinked polyethylene roll to block it, and then use a UV crosslinking device to irradiate the uncrosslinked polyethylene roll with UV light at a temperature of 80°C and an irradiation crosslinking time of 60s to obtain a waterproof roll with uncrosslinked splicing ends.

[0083] Example 6

[0084] Example 6 provides a process for preparing a puncture-resistant, flame-retardant polyethylene waterproof membrane, comprising the following steps:

[0085] (1) Weigh 66 parts of low-density polyethylene LD150, 10 parts of calcium carbonate, 5 parts of magnesium hydroxide, 1 part of triallyl isocyanurate, 2 parts of benzoin dimethyl ether, 15 parts of titanium dioxide and 1 part of antioxidant 1010; mix them at high speed to obtain a mixture.

[0086] (2) The mixture is added to a twin-screw extruder for extrusion granulation at an extrusion temperature of 200°C to obtain polyethylene roll masterbatch.

[0087] (3) The granulated polyethylene roll masterbatch is added to a single screw roll extrusion equipment for extrusion molding. The extrusion temperature is 180℃. Then, at the outlet of the extruder, an external magnetic field is applied to the extruded roll using an external magnetic field device. The strength of the external magnetic field is 20A / m, the length of the external magnetic field is 0.5m, and the processing temperature during the application of the magnetic field is 190℃ to obtain uncrosslinked polyethylene roll.

[0088] (4) Place a UV shielding plate on one side of the width direction of the uncrosslinked polyethylene roll to block it, and then use a UV crosslinking device to irradiate the uncrosslinked polyethylene roll with UV light at a temperature of 80°C and an irradiation crosslinking time of 20s to obtain a waterproof roll with uncrosslinked splicing ends.

[0089] Example 7

[0090] Example 7 provides a process for preparing a puncture-resistant, flame-retardant polyethylene waterproof membrane, comprising the following steps:

[0091] (1) Weigh 76 parts of low-density polyethylene LD150, 10 parts of calcium carbonate, 5 parts of magnesium hydroxide, 1 part of triallyl isocyanurate, 2 parts of benzoin dimethyl ether, 5 parts of titanium dioxide and 1 part of antioxidant 1010; mix them at high speed to obtain a mixture.

[0092] (2) The mixture is added to a twin-screw extruder for extrusion granulation at an extrusion temperature of 200°C to obtain polyethylene roll masterbatch.

[0093] (3) The granulated polyethylene roll masterbatch is added to a single screw roll extrusion equipment for extrusion molding. The extrusion temperature is 180℃. Then, at the outlet of the extruder, an external magnetic field is applied to the extruded roll using an external magnetic field device. The strength of the external magnetic field is 50A / m, the length of the external magnetic field is 0.5m, and the processing temperature during the application of the magnetic field is 190℃ to obtain uncrosslinked polyethylene roll.

[0094] (4) Place a UV shielding plate on one side of the width direction of the uncrosslinked polyethylene roll to block it, and then use a UV crosslinking device to irradiate the uncrosslinked polyethylene roll with UV light at a temperature of 80°C and an irradiation crosslinking time of 10s to obtain a waterproof roll with uncrosslinked splicing ends.

[0095] Example 8

[0096] Example 8 provides a process for preparing a puncture-resistant, flame-retardant polyethylene waterproof membrane, comprising the following steps:

[0097] (1) Weigh 76 parts of low-density polyethylene LD150, 10 parts of calcium carbonate, 5 parts of magnesium hydroxide, 1 part of triallyl isocyanurate, 2 parts of benzoin dimethyl ether, 5 parts of titanium dioxide and 1 part of antioxidant 1010; mix them at high speed to obtain a mixture.

[0098] (2) The mixture is added to a twin-screw extruder for extrusion granulation at an extrusion temperature of 200°C to obtain polyethylene roll masterbatch.

[0099] (3) The granulated polyethylene roll masterbatch is added to a single screw roll extrusion equipment for extrusion molding. The extrusion temperature is 180℃. Then, at the outlet of the extruder, an external magnetic field is applied to the extruded profile using an external magnetic field device. The strength of the external magnetic field is 10A / m, the length of the external magnetic field is 1m, and the processing temperature during the application of the magnetic field is 190℃ to obtain uncrosslinked polyethylene roll.

[0100] (4) Place a UV shielding plate on one side of the width direction of the uncrosslinked polyethylene roll to block it, and then use a UV crosslinking device to irradiate the uncrosslinked polyethylene roll with UV light at a temperature of 80°C and an irradiation crosslinking time of 10s to obtain a waterproof roll with uncrosslinked splicing ends.

[0101] Comparative Example

[0102] Comparative Example 1

[0103] Comparative Example 1 used low-density polyethylene LD150 as a control sample.

[0104] Comparative Example 2

[0105] Comparative Example 2 used metallocene polyethylene 1018ma as a control sample.

[0106] Comparative Example 3

[0107] Comparative Example 3 provides a process for preparing a puncture-resistant, flame-retardant polyethylene waterproof membrane, comprising the following steps:

[0108] (1) Weigh 81 parts of low-density polyethylene LD150, 10 parts of calcium carbonate, 5 parts of magnesium hydroxide, 1 part of triallyl isocyanurate, 2 parts of benzoin dimethyl ether and 1 part of antioxidant 1010; mix them at high speed to obtain a mixture.

[0109] (2) The mixture is added to a twin-screw extruder for extrusion granulation at an extrusion temperature of 200°C to obtain polyethylene roll masterbatch.

[0110] (3) The granulated polyethylene roll masterbatch is added to a single screw roll extrusion equipment for extrusion molding at an extrusion temperature of 190°C to obtain uncrosslinked polyethylene roll.

[0111] (4) Use ultraviolet crosslinking equipment to crosslink uncrosslinked polyethylene rolls with ultraviolet light at a temperature of 80°C and a crosslinking time of 60s to obtain waterproof rolls.

[0112] Comparative Example 4

[0113] Comparative Example 4 provides a preparation process for a puncture-resistant, flame-retardant polyethylene waterproof membrane, comprising the following steps:

[0114] (1) Weigh 76 parts of low-density polyethylene LD150, 10 parts of calcium carbonate, 5 parts of magnesium hydroxide, 1 part of triallyl isocyanurate, 2 parts of benzoin dimethyl ether, 5 parts of clay powder and 1 part of antioxidant 1010; stir at high speed to obtain a mixture.

[0115] (2) The mixture is added to a twin-screw extruder for extrusion granulation at an extrusion temperature of 200°C to obtain polyethylene roll masterbatch.

[0116] (3) The granulated polyethylene roll masterbatch is added to a single screw roll extrusion equipment for extrusion molding. The extrusion temperature is 180℃. Then, at the outlet of the extruder, an external magnetic field is applied to the extruded roll using an external magnetic field device. The strength of the external magnetic field is 50A / m, the length of the external magnetic field is 0.5m, and the processing temperature during the application of the magnetic field is 190℃ to obtain uncrosslinked polyethylene roll.

[0117] (4) Place a UV shielding plate on one side of the width direction of the uncrosslinked polyethylene roll to block it, and then use a UV crosslinking device to irradiate the uncrosslinked polyethylene roll with UV light at a temperature of 80°C and an irradiation crosslinking time of 20s to obtain a waterproof roll with uncrosslinked splicing ends.

[0118] Comparative Example 5

[0119] Comparative Example 5 provides a process for preparing a puncture-resistant, flame-retardant polyethylene waterproof membrane, comprising the following steps:

[0120] (1) Weigh 76 parts of low-density polyethylene LD150, 10 parts of calcium carbonate, 5 parts of DOPO flame retardant, 1 part of trimethylolpropane diallyl ether, 2 parts of benzoin dimethyl ether, 5 parts of talc and 1 part of antioxidant 1010; mix them at high speed to obtain a mixture.

[0121] (2) The mixture is added to a twin-screw extruder for extrusion granulation at an extrusion temperature of 200°C to obtain polyethylene roll masterbatch.

[0122] (3) The granulated polyethylene roll masterbatch is added to a single screw roll extrusion equipment for extrusion molding. The extrusion temperature is 180℃. Then, at the outlet of the extruder, an external magnetic field is applied to the extruded roll using an external magnetic field device. The strength of the external magnetic field is 50A / m, the length of the external magnetic field is 0.5m, and the processing temperature during the application of the magnetic field is 190℃ to obtain uncrosslinked polyethylene roll.

[0123] (4) Place a UV shielding plate on one side of the width direction of the uncrosslinked polyethylene roll to block it, and then use a UV crosslinking device to irradiate the uncrosslinked polyethylene roll with UV light at a temperature of 80°C and an irradiation crosslinking time of 20s to obtain a waterproof roll with uncrosslinked splicing ends.

[0124] Performance testing

[0125] (1) The waterproof performance, mechanical properties and thermal welding performance of the materials in the examples and comparative examples were tested according to the method of national standard GB 18173 "Polymer Waterproof Materials".

[0126] (2) Flame retardant performance test: The oxygen index of the materials in the examples and comparative examples was tested according to GB / T 2406.2-2009 "Determination of flammability of plastics by oxygen index method - Part 2: Room temperature test". The glow wire flammability index (GWFI) of the materials in the examples and comparative examples was tested according to GB / T 5169.11-2017 "Fire hazard test for electrical and electronic products".

[0127] The test results are shown in Table 1.

[0128] Table 1 Performance Test Tables for Examples and Comparative Examples

[0129]

[0130] Comparing the performance of Examples 1-3 and Comparative Example 1, it can be seen that compared with the low-density polyethylene LD150 control sample of Comparative Example 1, the flame retardant performance, puncture resistance, and mechanical properties of Examples 1-3 are significantly improved. Furthermore, the hot-welding performance and flexibility of Examples 1 are not significantly reduced compared to Comparative Example 1. This demonstrates that the cross-linking method used in this application can indeed improve the mechanical properties of the waterproof membrane, while the localized cross-linking gives the waterproof membrane good hot-welding performance and flexibility.

[0131] Furthermore, the performance of Examples 1-3 and Comparative Example 3 revealed that although Comparative Example 3 had better puncture resistance and mechanical properties, it was completely impossible to perform thermal welding. This was because Comparative Example 3 did not use a UV shielding agent, which caused the waterproof membrane to be almost completely cross-linked. This further demonstrates the advantage of this application in performing local cross-linking on the surface of the waterproof membrane.

[0132] Based on the performance of Comparative Examples 4, 5 and 1, it was found that Comparative Examples 4 and 5 were over-crosslinked, resulting in a significant decrease in flexibility and a substantial decrease in hot welding performance. This demonstrates the necessity of enriching the shielding agent on the surface of the roll material in this application, and also reflects the flexibility and convenience of combining the external magnetic field and titanium dioxide in this application.

[0133] In addition, comparing Examples 4 and 5, it was found that the flexibility, mechanical strength and hot welding performance of Example 5 were worse. This is because more calcium carbonate was added in Example 5. This shows that the process of applying a magnetic field and a charged shielding agent in this application will not have too much impact on the performance of the waterproof membrane itself, and can be applied more flexibly and is easier to promote.

[0134] Simultaneous analysis of the performance of Examples 6 and 7, as well as Example 1, revealed that the higher amount of shielding agent in Example 6 resulted in lower surface cross-linking of the waterproof membrane and a higher proportion of shielding agent, leading to poorer mechanical properties, puncture resistance, and tensile properties. In Example 7, the higher magnetic field strength caused excessive accumulation of shielding agent on the surface, affecting the formation of the surface cross-linked layer and resulting in poor surface puncture resistance. However, since the total amount of titanium dioxide remained unchanged, the tensile strength did not change significantly. This demonstrates that the interaction between the external magnetic field and the shielding agent, along with the formation of a localized cross-linked layer on the surface of the waterproof membrane, allows the waterproof membrane to possess excellent overall performance. Furthermore, the preparation process is simple, flexible, and widely applicable.

[0135] This specific embodiment is merely an explanation of this application and is not intended to limit it. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they fall within the scope of the claims of this application.

Claims

1. A preparation process for a puncture-resistant, flame-retardant polyethylene waterproof membrane, characterized in that, Includes the following steps: (1) Weigh the raw materials and stir the raw material components evenly to obtain a mixture; the raw materials of the waterproof membrane are composed of resin, crosslinking agent, photoinitiator and shielding agent, and the shielding agent is a charged ultraviolet shielding agent; (2) The mixture is extruded and granulated to obtain masterbatch; (3) The masterbatch is extruded and an external magnetic field is applied to the extruded roll material to enrich the shielding agent on one side of the extruded roll material, thus obtaining an uncrosslinked waterproof roll material. (4) Local ultraviolet light irradiation is applied to the side of the uncrosslinked waterproof membrane enriched with shielding agent to crosslink it, so as to obtain an uncrosslinked waterproof membrane at the splicing end.

2. The preparation process of a puncture-resistant and flame-retardant polyethylene waterproof membrane according to claim 1, characterized in that, The charged ultraviolet shielding agent includes titanium dioxide.

3. The preparation process of a puncture-resistant, flame-retardant polyethylene waterproof membrane according to claim 1, characterized in that, In step (3), the processing temperature during the application of the magnetic field is 190~225℃.

4. The preparation process of a puncture-resistant and flame-retardant polyethylene waterproof membrane according to claim 1, characterized in that, In step (3), the strength of the external magnetic field is 10~50 A / m, and the length of the external magnetic field is 0.5~1m.

5. The preparation process of a puncture-resistant, flame-retardant polyethylene waterproof membrane according to claim 1, characterized in that, In step (4), a UV shielding plate is used to cover the non-crosslinked areas of the uncrosslinked waterproof membrane.

6. The preparation process of a puncture-resistant, flame-retardant polyethylene waterproof membrane according to claim 1, characterized in that, In step (4), the UV crosslinking temperature is 70~80℃ and the time is 10~60s.

7. The preparation process of a puncture-resistant and flame-retardant polyethylene waterproof membrane according to claim 1, characterized in that, The raw materials of the waterproof membrane include the following components by weight: 54-95 parts polyethylene, 1-20 parts inorganic filler, 1-10 parts flame retardant, 1-2 parts crosslinking agent, 0.5-2 parts photoinitiator, 1-10 parts shielding agent and 0.5-2 parts anti-aging agent.

8. A waterproof membrane prepared according to the preparation process of the puncture-resistant flame-retardant polyethylene waterproof membrane according to any one of claims 1 to 7, characterized in that: It includes an uncrosslinked polyethylene layer (1) and a crosslinked polyethylene layer (2) located on one side of the uncrosslinked polyethylene layer (1).

9. An external magnetic field enrichment device for the preparation process of the puncture-resistant flame-retardant polyethylene waterproof membrane according to any one of claims 1 to 7, characterized in that, It includes an upper electromagnetic device (3) and a lower electromagnetic device (4) installed on the forming die (5) of the extruder, the upper electromagnetic device (3) and the lower electromagnetic device (4) being arranged opposite to each other.

10. An application of the puncture-resistant, flame-retardant polyethylene waterproof membrane as described in claim 8.

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