Light irradiation halogen-free polyolefin self-adhesive waterproof coiled material

Abstract

The invention discloses a light irradiation halogen-free polyolefin self-adhesive waterproof coiled material which is of a multi-layer composite structure and at least comprises an ultraviolet light irradiation cross-linked flame-retardant waterproof layer serving as a core, hot-melt pressure-sensitive adhesive self-adhesive layers compounded on the upper surface and the lower surface of the waterproof layer, and a buffer isolation layer compounded on the upper self-adhesive layer, the buffer isolation layer is combined with the upper self-adhesive layer in an intermittent bonding manner, so that a stress buffer stripping area is formed between the buffer isolation layer and the upper self-adhesive layer; the ultraviolet light irradiation crosslinking flame-retardant waterproof layer is formed by carrying out melt blending and on-line ultraviolet light irradiation crosslinking on a mixture comprising the following components in parts by weight. The light-irradiated halogen-free polyolefin self-adhesive waterproof coiled material thoroughly solves the technical problems of flammability, water channeling, poor durability, serious pollution and the like of the traditional waterproof material, and is particularly suitable for the fields of underground engineering, rail transit, industrial building and the like with strict requirements on safety, reliability and environmental protection.

Description

Technical Field

[0001] This invention relates to the field of building waterproofing materials technology, specifically to a light-irradiated halogen-free polyolefin self-adhesive waterproof membrane. Background Technology

[0002] The safety and durability of building waterproofing projects are directly related to the lifespan of building structures and the safety of people's lives and property.

[0003] Ultraviolet (UV) crosslinking technology, also known as "UV irradiation processing," has been applied in the field of polymer material modification and is an effective method for improving the mechanical properties and temperature resistance of polyolefins. Irradiating polymer materials under normal pressure in the extruded molten state causes no damage to the material, is highly efficient and energy-saving, allows the light to penetrate deep into the polymer, and produces no waste. The control method is simple and suitable for industrial and large-scale production. UV irradiation crosslinking only achieves the crosslinking reaction under UV irradiation, thus reducing the limitations on extrusion temperature. Even if the material remains in the die's dead corner, it will not form crosslinking defects, significantly extending continuous production time.

[0004] Intumescent flame retardants have been widely used in flame retardant materials due to their high flame retardancy and environmental friendliness. When heated, they can form an expanded char layer with good heat insulation and oxygen barrier properties. However, the compatibility between functional components and flame retardant matrix remains a difficult problem to solve.

[0005] Currently, mainstream waterproof membranes on the market, such as bitumen-based membranes, PVC membranes, and some TPO membranes, generally suffer from the following technical problems:

[0006] 1. Poor flame retardant properties, mostly flammable materials, posing a fire hazard;

[0007] 2. If the waterproof layer does not adhere firmly to the substrate, water seepage and leakage are likely to occur;

[0008] 3. The material has poor flexibility and weak impact resistance, making it easily damaged by hard objects;

[0009] 4. Traditional flame retardants often contain halogens, have poor environmental performance, and release toxic gases when burned. Summary of the Invention

[0010] The purpose of this invention is to provide a light-irradiated halogen-free polyolefin self-adhesive waterproof membrane to solve the existing technical problems mentioned in the background art.

[0011] To achieve the above objectives, the present invention provides the following technical solution: a light-irradiated halogen-free polyolefin self-adhesive waterproof membrane, which is a multi-layer composite structure and includes at least:

[0012] The core is an ultraviolet radiation cross-linked flame-retardant waterproof layer, a hot melt pressure-sensitive adhesive self-adhesive layer is laminated on the upper and lower surfaces of the waterproof layer, and a buffer isolation layer is laminated on the upper self-adhesive layer.

[0013] The buffer isolation layer is bonded to the upper self-adhesive layer by intermittent bonding, thereby forming a stress-buffered peeling zone between the two.

[0014] The ultraviolet-irradiated cross-linked flame-retardant and waterproof layer is formed by melt blending and online ultraviolet-irradiated cross-linking of a mixture comprising the following components in parts by weight:

[0015] —80-95 parts of polyolefin resin matrix, wherein the polyolefin resin matrix includes high-density polyethylene (HDPE), linear low-density polyethylene (LLDPE) and polyolefin elastomer (TPV).

[0016] —15-40 parts of halogen-free composite flame retardant;

[0017] —0.5-2.5 parts of ultraviolet photoinitiator;

[0018] —1-5 parts of multifunctional crosslinking agent.

[0019] Furthermore, the halogen-free composite flame retardant comprises:

[0020] Natural polysaccharides were modified and used as a carbon source;

[0021] Ammonium polyphosphate (APP) is used as both an acid source and a gas source;

[0022] Ultrafine metal hydroxides as synergistic smoke suppressants;

[0023] The mass ratio of ammonium polyphosphate to modified carbon source is (1.5:1) to (3:1).

[0024] Furthermore, the carbon source is maleic anhydride-modified starch (St).

[0025] Furthermore, the buffer isolation layer is a polyester filament singed geotextile, non-woven fabric, or polyethylene film, and its bonding area with the upper self-adhesive layer accounts for 30%-70% of the total area.

[0026] A method for preparing a halogen-free polyolefin self-adhesive waterproof membrane by light irradiation includes the following steps:

[0027] (1) Preparation of halogen-free composite flame retardant;

[0028] (2) Mix the polyolefin resin matrix, halogen-free composite flame retardant, ultraviolet photoinitiator, crosslinking agent and other additives evenly to obtain a waterproof layer mixture;

[0029] (3) The mixture is melt-blended and extruded into a sheet by a twin-screw extruder, and the sheet is immediately subjected to an online cross-linking reaction in an ultraviolet irradiation zone to form a flame-retardant and waterproof layer;

[0030] (4) Apply hot melt pressure-sensitive adhesive to the upper and lower surfaces of the flame-retardant and waterproof layer obtained in step (3) to form a self-adhesive layer;

[0031] (5) The buffer isolation layer material is bonded to the surface of the upper self-adhesive layer by intermittent glue application or composite method, and after cooling, traction, cutting and winding, the finished product is obtained.

[0032] Furthermore, the intensity of the ultraviolet irradiation in step (3) is 250-400 W / cm², and the irradiation time is 10-60 seconds.

[0033] Compared with the prior art, the beneficial effects of the present invention are:

[0034] 1. This invention features high flame retardancy and environmental friendliness: It adopts an original halogen-free composite flame retardant system with modified starch as the carbon source, combined with an ultraviolet cross-linking network. The product's flame retardant rating can reach UL-94 V-2 or higher. It produces low smoke and is non-toxic when burning, meeting the requirements of green buildings.

[0035] 2. This invention offers superior waterproof reliability and durability: the hot-melt pressure-sensitive adhesive achieves a permanent "skin-like" bond with concrete, combined with a stress buffer design in the "peel zone," effectively preventing water seepage, exhibiting strong resistance to substrate deformation, and ensuring a long system lifespan.

[0036] 3. The present invention has excellent comprehensive mechanical properties: through the synergistic effect of toughening with polyolefin elastomer and crosslinking enhancement by ultraviolet irradiation, the product simultaneously possesses high tensile strength, high elongation at break and excellent impact resistance.

[0037] 4. Green and efficient production process: Ultraviolet irradiation crosslinking is completed online at room temperature and pressure, with low energy consumption and no pollution, which is in line with the concept of clean production. Attached Figure Description

[0038] Figure 1 This is a flowchart of the ultraviolet irradiation crosslinking process in this invention;

[0039] Figure 2 This is a flowchart illustrating the preparation technology of the halogen-free composite flame retardant in this invention.

[0040] Figure 3 This is a diagram showing the formulation data of the intumescent flame-retardant TPV / APP / St composite material using starch as a carbon source in this invention;

[0041] Figure 4 This is a graph showing the experimental data on the effect of the APP to St ratio on the LOI of the flame-retardant TPV composite material in this invention.

[0042] Figure 5 This is a graph showing the experimental data on the effect of the amount of the compound flame retardant system on the flame retardancy of TPV composite materials in this invention;

[0043] Figure 6 This is a comparison chart of samples after LOI testing of TPV and TASt30% in this invention. Detailed Implementation

[0044] In the description of this invention, unless otherwise stated, "a plurality of" means two or more; the terms "upper," "lower," "left," "right," "inner," "outer," "front end," "rear end," "head," "tail," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, the terms "first," "second," "third," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0045] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "connected" and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0046] According to the formula (e.g.) Figure 3 Weigh out the flame retardant system and polyolefin elastomer TPV, mix them evenly, and place them in a torque rheometer. Knead at 180℃ and 40r / min for 6 minutes to prepare TPV / APP / St flame retardant TPV composite materials. Then, place the obtained composite materials into corresponding molds and mold them using a flat vulcanizing machine (process parameters: temperature 185℃; preheating 5min, hot pressing 4min, cold pressing 2min, pressure 10MPa) to obtain the required samples.

[0047] Results of the influence of "APP to St ratio" on the LOI of flame-retardant TPV composite materials ( Figure 4 ),from Figure 1It can be seen that the limiting oxygen index (LOI) of pure TPV is 19.0%, while the LOI of the TASt7 composite material with only added st is not significantly different. This indicates that adding st alone cannot improve the flame retardant properties of TPV composites. Only the simultaneous addition of APP and st significantly improves the LOI of the composite material, and the LOI of the composite material reaches its highest value (25%) when the ratio of APP to st is 2:1. This shows that APP and st have a synergistic flame retardant effect, and the synergistic effect is best when the addition ratio is 2:1.

[0048] Related to the flame retardant mechanism of IFR, when the intumescent flame retardant composite material burns, APP will first decompose to produce phosphoric acid, polyphosphoric acid and some non-flammable gases. Then, under the action of acid, St will undergo a carbonization reaction to form a carbon layer. The non-flammable gases will cause the carbon layer to expand, thus forming an expanded carbon layer.

[0049] It is evident that APP needs to reach a certain ratio with St to function better. Too little APP will result in too little acid or gas produced during decomposition, and the carbon source cannot be fully carbonized. Too much APP will result in less carbon formation and excessive gas production during decomposition, which will damage the structure of the carbon layer.

[0050] and through ( Figure 5 As shown in the image:

[0051] Pure TPV material has a LOI of only 19.0%, classifying it as an extremely flammable material. However, adding flame retardants to TPV improves the LOI of the resulting flame-retardant TPV composites. Furthermore, the LOI of the composites increases with the amount of flame retardant added, and the UL-94 rating of the material also increases. When the mass fraction of the flame retardant system reaches 30%, the LOI of TASt30% can be increased to 25.0%, achieving a V-2 rating.

[0052] In the horizontal combustion experiment, the TPV material with intumescent flame retardant also exhibited a similar pattern to that shown in the limiting oxygen index experiment—the flame retardant performance of the flame retardant / TPV composite material improved with the addition of intumescent flame retardant. The TASt 30% sample burned 50 mm in 177 s, with a burning rate of 0.282 mm / s, which was 41.9% slower than the 0.485 mm / s of the pure TPV sample, indicating better flame retardant performance. On the other hand, after adding intumescent flame retardant, the flame-retardant TPV showed slow dripping during the horizontal combustion experiment, indicating that the intumescent flame retardant with starch as the carbon source was effective in suppressing dripping. Finally, the flame-retardant TPV / APP / St composite material also produced bubbles during combustion, indicating that the thermal decomposition process of APP was relatively smooth and could effectively assist in the formation of the char layer.

[0053] like Figure 6As shown, pure TPV remains smooth and flat after combustion, with only a very small amount of waxy residue remaining on the surface. It fails to form a char layer and cannot prevent the decomposition and combustion of the TPV substrate. In contrast, TASt30% exhibits a distinct char layer covering the substrate after combustion, and these expanded char layers provide better protection for the substrate.

[0054] Example 1:

[0055] 1. Raw material formula (waterproof layer, by weight):

[0056] -High-density polyethylene (HDPE): 20 parts;

[0057] - Linear low-density polyethylene (LLDPE): 30 parts;

[0058] - Polyolefin elastomer (POE, ethylene-octene copolymer): 35 parts;

[0059] - Halogen-free composite flame retardant: 15 parts (of which, ammonium polyphosphate APP: modified starch St = 10:5, i.e., mass ratio 2:1);

[0060] - Ultrafine magnesium hydroxide (synergistic smoke suppressant): 5 parts;

[0061] - Ultraviolet photoinitiator (benzophenone BP): 0.8 parts;

[0062] - Multifunctional crosslinking agent (tracene propyl isocyanurate TAIC): 1.5 parts;

[0063] - Antioxidant 1010: 0.3 parts

[0064] 2. Preparation method:

[0065] a. Preparation of composite flame retardant: Maleic anhydride-modified starch, APP, and ultrafine magnesium hydroxide are mixed evenly at high speed according to the above proportion.

[0066] b. Mixing: Put all the above raw materials into a high-speed mixer and premix them evenly.

[0067] c. Melt extrusion and crosslinking: The premixed material is added to a twin-screw extruder and melt-plasticized at 180-200℃. The extruded molten sheet is immediately passed through an ultraviolet irradiation device and irradiated with ultraviolet light at an intensity of 320W / cm² for 25 seconds to initiate a crosslinking reaction.

[0068] d. Calendering and cooling: The cross-linked sheet is shaped and cooled by a three-roll calender (temperature settings: upper roll 80℃, middle roll 60℃, lower roll 30℃) to obtain a flame-retardant and waterproof layer.

[0069] e. Adhesive application and lamination: Environmentally friendly hot-melt pressure-sensitive adhesive with polyvinyl alcohol as the main raw material is uniformly applied to the upper and lower surfaces of the waterproof layer. The adhesive layer on the upper surface is applied in strips (the bonding area accounts for about 50% of the total area) and laminated with polyester filament singed geotextile (buffer layer) to form a "peeling zone"; the lower surface is fully coated with adhesive and covered with a release film.

[0070] f. Rewinding: After being pulled and cut, the waterproof membrane is rewound to obtain the finished product.

[0071] 3. Performance test results:

[0072] The prepared waterproof membrane was tested according to GB / T23457-2017 "Pre-laid Waterproof Membranes" and UL-94 standard, and its main performance characteristics are as follows:

[0073] - Tensile strength (longitudinal / transverse): 22.5MPa / 20.8MPa;

[0074] -Elongation at break (longitudinal / transverse): 785% / 720%;

[0075] -Low-temperature bending performance (-35℃): No cracks;

[0076] - Peel strength from post-cast concrete: 2.8 N / mm;

[0077] -Oxygen Index (LOI): 32.5%;

[0078] -UL-94 Vertical Flammability Rating: V-2;

[0079] All indicators are better than the national standard requirements, with flame retardancy and bonding strength showing outstanding performance.

[0080] Example 2:

[0081] Optimize the flame retardant system and adjust the waterproof layer formula to improve flame retardancy rating:

[0082] The water resistance is improved by replacing APP in the composite flame retardant with partially coated APP.

[0083] The proportion of DOPO-modified starch was increased, and a small amount of zinc borate was introduced as a synergist.

[0084] The total number of composite flame retardants has increased to 25 parts.

[0085] Performance improvements:

[0086] The oxygen index (LOI) increased to ≥35.0%.

[0087] The UL-94 vertical flammability rating is V-1.

[0088] Cone calorimetry tests showed that the peak heat release rate (pHRR) and total heat release (THR) decreased by more than 50% compared to the control group.

[0089] It is understood that the above embodiments are merely exemplary implementations used to illustrate the principles of the present invention, and the present invention is not limited thereto. For those skilled in the art, various modifications and improvements can be made without departing from the spirit and essence of the present invention, and these modifications and improvements are also considered to be within the scope of protection of the present invention.

Claims

1. A light-irradiated halogen-free polyolefin self-adhesive waterproof membrane, characterized in that, It is a multi-layered composite structure, comprising at least: The core is an ultraviolet radiation cross-linked flame-retardant waterproof layer, a hot melt pressure-sensitive adhesive self-adhesive layer is laminated on the upper and lower surfaces of the waterproof layer, and a buffer isolation layer is laminated on the upper self-adhesive layer. The buffer isolation layer is bonded to the upper self-adhesive layer by intermittent bonding, thereby forming a stress-buffered peeling zone between the two. The ultraviolet-irradiated cross-linked flame-retardant and waterproof layer is formed by melt blending and online ultraviolet-irradiated cross-linking of a mixture comprising the following components in parts by weight: —80-95 parts of polyolefin resin matrix, wherein the polyolefin resin matrix includes high-density polyethylene (HDPE), linear low-density polyethylene (LLDPE) and polyolefin elastomer (TPV). —15-40 parts of halogen-free composite flame retardant; —0.5-2.5 parts of ultraviolet photoinitiator; —1-5 parts of multifunctional crosslinking agent.

2. The halogen-free, light-irradiated polyolefin self-adhesive waterproof membrane according to claim 1, characterized in that: The halogen-free composite flame retardant comprises: Natural polysaccharides were modified and used as a carbon source; Ammonium polyphosphate (APP) is used as both an acid source and a gas source; Ultrafine metal hydroxides as synergistic smoke suppressants; The mass ratio of ammonium polyphosphate to modified carbon source is (1.5:1) to (3:1).

3. The halogen-free, light-irradiated polyolefin self-adhesive waterproof membrane according to claim 1, characterized in that: The carbon source is maleic anhydride-modified starch (St).

4. The halogen-free, light-irradiated polyolefin self-adhesive waterproof membrane according to claim 1, characterized in that: The buffer isolation layer is a polyester filament singed geotextile, non-woven fabric or polyethylene film, and its bonding area with the upper self-adhesive layer accounts for 30%-70% of the total area.

5. A method for preparing a light-irradiated crosslinked halogen-free flame-retardant self-adhesive waterproof membrane as described in any one of claims 1-6, characterized in that, Includes the following steps: (1) Preparation of halogen-free composite flame retardant; (2) Mix the polyolefin resin matrix, halogen-free composite flame retardant, ultraviolet photoinitiator, crosslinking agent and other additives evenly to obtain a waterproof layer mixture; (3) The mixture is melt-blended and extruded into a sheet by a twin-screw extruder, and the sheet is immediately subjected to an online cross-linking reaction in an ultraviolet irradiation zone to form a flame-retardant and waterproof layer; (4) Apply hot melt pressure-sensitive adhesive to the upper and lower surfaces of the flame-retardant and waterproof layer obtained in step (3) to form a self-adhesive layer; (5) The buffer isolation layer material is bonded to the surface of the upper self-adhesive layer by intermittent glue application or composite method, and after cooling, traction, cutting and winding, the finished product is obtained.

6. The method according to claim 5, characterized in that, The intensity of ultraviolet irradiation in step (3) is 250-400 W / cm², and the irradiation time is 10-60 seconds.

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