Halogen-free flame-retardant polyolefin material as well as preparation method and application thereof

Abstract

The invention discloses a halogen-free flame-retardant polyolefin material as well as a preparation method and application thereof. The halogen-free flame-retardant polyolefin material is prepared from the following raw materials in parts by mass: 25 to 40 parts of polyethylene resin, 25 to 30 parts of polypropylene resin, 35 to 50 parts of phosphorus-nitrogen flame-retardant master batch and 0.1 to 0.5 part of antioxidant. The melt index of the polyethylene resin under the conditions that the temperature is 190 DEG C and the load is 2.16 kg is 40-80 g / 10 min; the polypropylene resin has a melt index of 20-60 g / 10 min at a temperature of 230 DEG C under a load of 2.16 kg and a cantilever beam impact strength of at least 300 J / m. The halogen-free flame-retardant polyolefin material disclosed by the invention is good in flowability and moderate in crystallization rate, and has excellent cohesiveness and stiffness while maintaining excellent processability.

Description

Technical Field

[0001] The invention relates to the technical field of polymer materials, and in particular to a halogen-free flame-retardant polyolefin material and a preparation method and application thereof. Background Art

[0002] Both polyethylene (PE) and polypropylene (PP) have the advantages of being odorless, non-toxic, excellent in low temperature resistance, good chemical stability, resistance to most acids and alkalis, low water absorption, and excellent electrical insulation. They are widely used in chemical, agricultural, construction, and packaging fields.

[0003] Polyethylene is widely used in simulated Christmas tree pine leaves or some simulated garden landscape trees due to its good simulation effect. The amount of polyethylene is increasing. The oxygen index of polyethylene is about 17, which is a flammable material. If the main material has poor flame retardant performance, the risk of fire is increasing, so flame retardant modification is needed. There are many directions for flame retardant modification of polyethylene. Bromine antimony flame retardant system is the most widely used flame retardant modification method, but many bromine antimony flame retardants are on the list of banned substances in European and American countries, with potential carcinogenic risks, and are environmentally unfriendly flame retardants. Phosphorus nitrogen flame retardant system belongs to the category of halogen-free flame retardant system, with better environmental protection and high flame retardant efficiency. It can reach UL94V-0 level by expanding solid phase into carbon. However, adding flame retardant to polyethylene will reduce its viscosity, resulting in a significant deterioration in the adhesion of the mixture. In specific applications, it cannot be bonded with other materials and maintain the shape without falling off. Summary of the invention

[0004] The present invention aims to solve at least one of the above technical problems existing in the prior art. To this end, the purpose of the present invention is to provide a halogen-free flame-retardant polyolefin material and a preparation method and application thereof, wherein the polyolefin material has at least one of excellent bonding performance, flame retardant performance and stiffness.

[0005] In order to achieve the above object, the technical solution adopted by the present invention is:

[0006] The first aspect of the present invention provides a halogen-free flame-retardant polyolefin material, comprising the following raw materials in parts by weight: 25 to 40 parts of polyethylene resin, 25 to 30 parts of polypropylene resin, 35 to 50 parts of phosphorus nitrogen flame retardant masterbatch, and 0.1 to 0.5 parts of antioxidant; the polyethylene resin has a melt index of 40 to 80 g / 10 min at a temperature of 190° C. and a load of 2.16 kg; the polypropylene resin has a melt index of 20 to 60 g / 10 min at a temperature of 230° C. and a load of 2.16 kg, and the cantilever beam impact strength is at least 300 J / m.

[0007] The mixture of polyethylene resin and polyvinyl chloride or polyester has good adhesion, but adding flame retardant will reduce the viscosity of polyethylene, resulting in a significant deterioration in the adhesion of the mixture, and it cannot be bonded to other materials and keep the shape without falling off in specific applications. In the present invention, a high melt index polyethylene resin with a melt index of 40 to 80 g / 10min (such as 50 g / 10min, 55 g / 10min, 60 g / 10min, 65 g / 10min, 70 g / 10min, 75 g / 10min) is used to provide the polyolefin material with good fluidity, and the material can be injection molded into different shapes. This type of polyethylene resin can also reduce the overall processing temperature of the polyolefin material. Similarly, the use of polypropylene resin with a melt index of 20 to 60 g / 10min (such as 30 g / 10min, 35 g / 10min, 40 g / 10min, 45 g / 10min, 50 g / 10min, 55 g / 10min) can also improve the fluidity of polyolefin materials and improve processing performance; the use of polypropylene resin with an impact strength of at least 300 J / m (such as at least 350 J / m, at least 400 J / m, at least 500 J / m, at least 600 J / m, 300 to 700 J / m, etc.) allows the material to still maintain a certain toughness after the addition of flame retardants, greatly improving the stress cracking of polyethylene resins and maintaining the stiffness of polyolefin materials. The molecular chain of polyethylene is relatively dense, and it takes a longer time to arrange the molecular chain during the crystallization process, while the molecular chain of polypropylene is easier to form a crystal structure, so the crystallization speed is faster. During injection molding, polypropylene can improve the viscosity of polyolefin materials and keep them fixed after cooling without falling off; further, the amount ratio of the two is controlled within the range of 25-40 parts / 25-30 parts, which can balance the bonding ability and crystallization speed of polyolefin materials. If the amount of polyethylene resin is too much, the bonding of polyolefin materials will decrease. If the amount of polypropylene resin is too much, the crystallization speed of polyolefin materials will be too fast, resulting in serious shrinkage and deformation of the material during injection molding. Therefore, the polyolefin material of the present invention has higher flame retardant properties and can maintain good bonding properties, stiffness and crystallization rate.

[0008] In the present invention, the melt index can be measured according to GB / T-3682-2000. The cantilever beam impact strength is tested according to ASTM D256-2019 standard, with a thickness of 3.2 mm.

[0009] In some embodiments of the present invention, the phosphorus-nitrogen flame retardant masterbatch comprises the following raw materials in parts by weight: 20 to 35 parts of polyethylene resin, 60 to 75 parts of phosphorus-nitrogen compound flame retardant, and 1 to 3 parts of lubricant polyethylene wax; such as 23 to 33 parts of polyethylene resin, 65 to 75 parts of phosphorus-nitrogen compound flame retardant, and 1 to 3 parts of lubricant polyethylene wax; the phosphorus-nitrogen compound flame retardant comprises a phosphorus-nitrogen compound intumescent flame retardant, such as at least one of ammonium polyphosphate flame retardant and piperazine pyrophosphate flame retardant, and the phosphorus-nitrogen compound flame retardant comprises a phosphorus-nitrogen compound intumescent flame retardant. The piperazine pyrophosphate system flame retardant of the retardant integrates acid source, gas source and carbon source, and has excellent carbonization and flame retardant properties, such as at least one of EPFR-110G, EPFR-110DM, EPFR-110DL and EPFR-110DN of Presbyo Chemical. It has good dispersibility, good heat resistance and high decomposition temperature. TGA shows that its 1% decomposition temperature is 265°C, which is much higher than other phosphorus-containing flame retardants such as ammonium polyphosphate. The flame retardant polyolefin material made from it has better flame retardant stability.

[0010] In some embodiments of the present invention, in order to improve the compatibility between the phosphorus-nitrogen flame retardant masterbatch and the substrate, the polyethylene resin in the raw material for preparing the phosphorus-nitrogen flame retardant masterbatch can be the same polyethylene resin as the substrate.

[0011] In some embodiments of the present invention, the preparation method of the phosphorus nitrogen flame retardant masterbatch comprises heating and kneading the raw materials, extruding and then pelletizing; the kneading temperature is 120-140°C, such as 120-135°C.

[0012] In some embodiments of the present invention, the halogen-free flame-retardant polyolefin material comprises the following raw materials in parts by weight: 25-40 parts of polyethylene resin, 26-29 parts of polypropylene resin, 40-46 parts of phosphorus nitrogen flame-retardant masterbatch, and 0.1-0.5 parts of antioxidant.

[0013] In some embodiments of the present invention, the halogen-free flame-retardant polyolefin material further includes an anti-UV agent, which can give the polyolefin material anti-UV properties, and in practical applications, can be used outdoors; the anti-UV agent includes at least one of ultraviolet absorbers UV-770, UV-531, UV-284, UV-538, UV-234, UV-326 or UV-327. In addition, based on the total weight of the polyolefin material as 100 parts by weight, the content of the anti-UV agent can be 0.05-3 parts by weight, such as 0.1-2 parts by weight, 0.1-1.0 parts by weight, 0.1-0.8 parts by weight, 0.1-0.5 parts by weight, etc.

[0014] In some embodiments of the present invention, the halogen-free flame-retardant polyolefin material also includes a lubricant, which can improve the extrusion processing performance of the polyolefin material. The type and amount of the lubricant can be conventionally selected in the art, for example, the lubricant can include at least one of polyethylene glycol (PEG) lubricants, fluoropolymer lubricants, silicone lubricants, fatty alcohol lubricants, fatty acid lubricants, fatty acid ester lubricants, stearic acid amide lubricants, fatty acid metal soap lubricants, alkanes and oxidized alkanes lubricants or micro-nano particle lubricants. Specifically, the PEG lubricant can be, for example, a PEG molecule with a molecular weight of 500-50000, which can be treated by end-capping, grafting, cross-linking, or other chemical modifications or physical modifications. The fluoropolymer lubricant can be, for example, at least one of polytetrafluoroethylene, polyvinylidene fluoride, polyhexafluoropropylene, etc., or other unimodal or multimodal fluoropolymers and crystalline or semi-crystalline fluoropolymers. The organosilicon lubricant can be any existing compound with carbon and silicon atoms as the main molecular chain and oligomers or polymers of organic groups such as methyl, phenyl, alkoxy, vinyl, etc. as the side chain. The fatty alcohol lubricant can be, for example, at least one of soft fatty alcohol, stearic alcohol, tallow fatty alcohol, etc. The fatty acid lubricant can be, for example, stearic acid and / or 12-hydroxystearic acid. The fatty acid ester lubricant can be, for example, at least one of butyl stearate, monoglyceride of stearic acid, palmitic acid hexadecyl ester, stearic acid octadecyl ester, etc. The stearic acid amide lubricant can be, for example, at least one of stearic acid amide, oleamide, erucic acid amide, n,n-ethylene bis stearic acid amide (EBS), etc. The fatty acid metal soap lubricant can be, for example, at least one of lead stearate, calcium stearate, magnesium stearate, synthetic calcium acetate, etc. The alkane and alkane oxide lubricant can be, for example, at least one of liquid paraffin, paraffin wax, polyethylene wax, polypropylene wax, ethylene oxide wax, etc. The micro-nano particle lubricant can be, for example, powdered rubber and / or silica gel particles. In addition, based on the total weight of the polyolefin material as 100 parts by weight, the content of the lubricant can be 0.05-5 parts by weight, such as 0.1-3 parts by weight, 0.1-2 parts by weight, 0.1-1.0 parts by weight, etc.

[0015] In some embodiments of the present invention, the halogen-free flame-retardant polyolefin material also includes an anti-dripping agent, and the anti-dripping agent is polytetrafluoroethylene. Polytetrafluoroethylene can not only prevent melting dripping and improve flame retardant properties, making it easy for the material to meet the requirements of ULV-0, but also increase melt strength and bending modulus, while reducing costs and enhancing product competitiveness. Optionally, in some specific examples of the present invention, the anti-dripping agent uses pure polytetrafluoroethylene or coated polytetrafluoroethylene, which will make the performance more excellent. In addition, based on the total weight of the polyolefin material as 100 parts by weight, the content of the anti-dripping agent can be 0.05-3 parts by weight, such as 0.1-2 parts by weight, 0.1-1.0 parts by weight, 0.1-0.8 parts by weight, 0.1-0.5 parts by weight, etc.

[0016] The second aspect of the present invention provides a method for preparing the halogen-free flame-retardant polyolefin material, comprising the following steps: mixing the raw materials for preparing the halogen-free flame-retardant polyolefin material, plasticizing, extruding and pelletizing to obtain the halogen-free flame-retardant polyolefin material.

[0017] In some embodiments of the present invention, the preparation method of the halogen-free flame-retardant polyolefin material comprises the following steps: mixing the other raw materials except the phosphorus-nitrogen flame-retardant masterbatch in the preparation raw materials of the halogen-free flame-retardant polyolefin material, and then mixing with the phosphorus-nitrogen flame-retardant masterbatch, plasticizing, extruding, and pelletizing to obtain the halogen-free flame-retardant polyolefin material. In the present invention, the phosphorus-nitrogen flame-retardant masterbatch is evenly dispersed during the preparation process, and the base material is a polyethylene resin with a large melt index. After the phosphorus-nitrogen flame-retardant masterbatch is added, it can be quickly melted and fully mixed with the main material. The later addition can also reduce the shearing time, reduce the influence of shear heat on the flame retardant, and thus reduce the decomposition problem caused by overheating.

[0018] In some embodiments of the present invention, the method for preparing the halogen-free flame retardant polyolefin material comprises the following steps: mixing the other raw materials except the phosphorus nitrogen flame retardant masterbatch in the preparation raw materials of the halogen-free flame retardant polyolefin material, feeding them from the main feed of a twin-screw extruder, feeding the nitrogen flame retardant masterbatch from the side feed, plasticizing, extruding, cooling, drying and pelletizing in the twin-screw extruder to obtain the halogen-free flame retardant polyolefin material.

[0019] In some embodiments of the present invention, the extrusion temperature is 170-190°C, such as 175-185°C.

[0020] In some embodiments of the present invention, the screw length-to-diameter ratio of the twin-screw extruder is 44-48:1, and the feeding screw of the side feeding is a large-groove conveying element, which facilitates the conveying of granular materials.

[0021] The third aspect of the present invention provides an injection molding material, comprising the halogen-free flame-retardant polyolefin material.

[0022] A fourth aspect of the present invention provides a simulated decorative article, which is made of the halogen-free flame-retardant polyolefin material.

[0023] In some embodiments of the present invention, the simulated decorations include indoor and / or outdoor simulated decorations, such as simulated garden decorations, such as simulated plants, simulated animals, etc.

[0024] The beneficial effects of the present invention are:

[0025] The halogen-free flame-retardant polyolefin material of the present invention has good fluidity and moderate crystallization rate. While maintaining excellent processing performance, it has excellent adhesion and stiffness, a melt index of >20g / 10min (at a temperature of 190°C and a load of 2.16Kg), can be formed into various shapes and is suitable for different injection molding machines (vertical injection molding machines and horizontal injection molding machines).

[0026] The preparation method of the halogen-free flame-retardant polyolefin material of the present invention is relatively simple, easy to realize large-scale production, low in cost and stable in product quality.

[0027] Some embodiments of the halogen-free flame-retardant polyolefin material of the present invention have excellent flame retardant properties, which can reach 1.5mmUL94V-0. The manufactured simulated leaf bones or trunks are ignited with a lighter for 30 seconds without causing flame extension and molten droplets. The flame retardant has good flame retardancy and safety. The flame retardant is halogen-free and environmentally friendly, and can meet the RoHs 2.0 and SVCH control of substances of very high concern.

[0028] Some embodiments of the halogen-free flame-retardant polyolefin material of the present invention have excellent weather resistance and can be used outdoors. After being tested for 1000 hours under the conditions of Cycle 1 of ASTM G154-12a, the color difference ΔE is less than 3.0, and the tensile strength retention rate is ≥70%. DETAILED DESCRIPTION

[0029] The present invention is further described in detail below by specific examples. Unless otherwise specified, the raw materials, reagents or devices used in the examples and comparative examples can be obtained from conventional commercial sources or can be obtained by prior art methods. Unless otherwise specified, the experiments or test methods are conventional methods in the art.

[0030] In the following examples or comparative examples, the raw materials used for preparation are as follows:

[0031] The melt index of LDPE MG70 is 70g / 10min (190℃, 2.16Kg), Qatar Petrochemical;

[0032] The melt index of LDPE 2420H is 2g / 10min (190℃, 2.16Kg), Guangzhou Petrochemical;

[0033] The melt index of PP K9960 is 45g / 10min (230℃, 2.16Kg), and the cantilever beam impact strength is 550J / m, Maoming Petrochemical;

[0034] The melt index of PP HP500N-Z is 10g / 10min (230℃, 2.16Kg), and the Izod impact strength is 30J / m, CNOOC Shell;

[0035] Flame retardants: EPFR-110G and EPFR-100C, Qingyuan Pusai Fulin Chemical Co., Ltd.;

[0036] Lubricant: polypropylene wax LICOCENE PP 6102FINE GRAIN, produced by Clariant;

[0037] Antioxidant: B215, Tianjin Lianlong New Materials Co., Ltd.;

[0038] Anti-UV agent: UV-531, Tianjin Lianlong New Materials Co., Ltd.

[0039] Lubricant: PE wax, LP0100F, SCG Chemicals, Thailand;

[0040] The anti-dripping agent PTFE FD310 is produced by Lu Poly Chemical.

[0041] The preparation method of phosphorus nitrogen flame retardant masterbatch is as follows: after the resin, compound flame retardant and lubricant polyethylene wax are mixed in an internal mixer at a temperature of 120-135°C for 5 minutes, they are removed and added into a single screw extruder with a length-to-diameter ratio of 36:1 for extrusion and then hot-cut into finished flame retardant masterbatch products.

[0042] Example 1

[0043] This example prepares a polyolefin material, and the specific process is as follows:

[0044] Polyethylene resin, polypropylene resin, antioxidant, anti-UV agent, lubricant and anti-dripping agent are mixed uniformly in stirring according to the proportions in Table 1, and then added into the feeding section of the twin-screw extruder from the main feed, and the phosphorus nitrogen flame retardant masterbatch is fed into the twin-screw extruder through the side feed, and after being plasticized uniformly in the twin-screw extruder and extruded into strands, the material is mixed uniformly through a water tank, a blow dryer, a pelletizer, a vibrating screen and a large mixing barrel to form a halogen-free flame retardant polyolefin material with good adhesion; wherein, the extrusion temperature of the twin-screw extruder is set to 175-185°C, the screw aspect ratio is 44-48:1, and the feeding screw of the side feed is a large screw groove conveying element, which is convenient for conveying granular materials.

[0045] Among them, the raw materials for preparing the phosphorus-nitrogen flame retardant masterbatch are according to Table 2, and the preparation method is as mentioned above.

[0046] The raw material proportions of Examples 2, 5, and 6 and Comparative Examples 1 to 4 are as shown in Table 1, and the preparation method refers to that of Example 1 above.

[0047] Embodiment 3-4

[0048] Examples 3 to 4 prepared polyolefin materials. The difference from Example 1 is that the phosphorus nitrogen flame retardant masterbatch was added through the main feeding screw and the side feeding feeder was removed. The raw material proportions are shown in Table 1. The preparation process refers to Example 1.

[0049] Comparative Example 5

[0050] This comparative example prepares a polyolefin material, which is different from Example 1 in that the polyethylene resin of the phosphorus nitrogen flame retardant masterbatch is changed to polypropylene resin PP K9960, and the phosphorus nitrogen flame retardant masterbatch is 33 parts of polypropylene resin PP K9960, 65 parts of compound flame retardant EPFR-110G, and 2 parts of lubricant polyethylene wax. After being mixed in a mixer at a temperature of 165-175°C for 5 minutes, it is removed and added to a single screw extruder with a length-to-diameter ratio of 36:1 for extrusion and then hot-cut into a phosphorus nitrogen flame retardant masterbatch finished product. The raw material ratio is shown in Table 1, and the other preparation processes refer to Example 1.

[0051] Table 1 Composition of polyolefin materials (unit: parts by weight)

[0052]

[0053] Table 2 Phosphorus nitrogen flame retardant masterbatch raw material composition (unit: weight parts)

[0054]

[0055]

[0056] Test example

[0057] This test example tests the polyolefin materials obtained in the examples and comparative examples, and the obtained polyolefin materials are injection molded using a Haitian horizontal injection molding machine to obtain standard samples. Molding process conditions: injection temperature (feeding port) 170℃ / 175℃ / 175℃ / 180℃ (nozzle); injection pressure 45MPa; holding time 10s; cooling time 12s. The performance tests are carried out respectively, and the performance test standards are as follows. The results are shown in Table 3.

[0058] Among them, the performance test methods or standards are as follows:

[0059] Melt index: tested according to ASTM D1238-2010 standard, 190℃, 2.16Kg;

[0060] Flexural modulus: tested according to ASTM D790-2010 standard, thickness 3.2mm specimen;

[0061] Tensile strength and elongation at break: tested in accordance with ASTM D638-2019 standard, 3.2mm thick specimen;

[0062] Izod notched impact performance: tested in accordance with ASTM D256-2019 standard, with a thickness of 3.2 mm;

[0063] Flame retardant test: tested according to UL94 standard, vertical burning test on 1.5mm thick specimens;

[0064] Anti-UV test: The flame-retardant polyolefin materials prepared in the examples and comparative examples were injection molded into 10mm*10mm*3mm (±0.5mm) square plates in an injection molding machine, and the color difference ΔE and tensile strength retention of the square plates were tested for 1000h under the conditions of Cycle 1 of ASTM G154-12a.

[0065] Evaluation of adhesion: The flame-retardant polyolefin materials prepared in the embodiments and comparative examples were injection molded on a vertical injection molding machine. PET simulated leaves were laid on the mold. The adhesion between the leaf bones and the leaves after injection molding was observed. The adhesion was divided into three grades (Grade A: firm adhesion, no cracking; Grade B: a small amount of adhesion was not completely tight; Grade C: completely not adhered and could be easily torn apart).

[0066] Table 3 Test results of polyolefin properties of examples and comparative examples

[0067]

[0068]

[0069] As can be seen from Table 3, the polyolefin materials obtained in the embodiments all have good adhesion, bending strength and impact strength, and all solve the defects of poor adhesion of traditional polyolefin materials. In Example 3 and Comparative Example 5, the phosphorus nitrogen flame retardant masterbatch or flame retardant is directly added to the twin-screw base machine from the main feeding port. Since the flame retardant is sheared by the twin-screw extruder, the flame retardant has been partially decomposed, and its flame retardant effect has decreased. Correspondingly, the base polyethylene resin in the phosphorus nitrogen flame retardant masterbatch is beneficial to improve the impact strength of the polyolefin material. The flame retardant effect and impact strength of the polyolefin in Example 3 can be improved by a suitable feeding method and a phosphorus nitrogen flame retardant masterbatch with a polyethylene resin base. Example 5 does not add an anti-UV agent, and its weather resistance is naturally poor, which leads to a low tensile strength retention rate and a large color difference after UV irradiation; the flame retardant of Example 6 is an ammonium polyphosphate system, which has lower heat resistance, poorer dispersion effect, lower flame retardant efficiency, and reduced flame retardant performance and adhesion compared to the pyrophosphate piperazine system. According to the actual application scenario, the polyolefin materials of Examples 3 to 6 with suitable performance can be selected, and the above defects can still be improved through appropriate ways, such as by adding phosphorus nitrogen flame retardant masterbatch, anti-UV agent and antioxidant. The polyolefin materials of Examples 1 and 2 are excellent in flame retardancy, anti-UV performance and antioxidant performance, so that after being tested for 1000h under the conditions of Cycle 1 of ASTM G154-12a, the color difference ΔE is less than 3.0, and the tensile strength retention rate is ≥80%. The flame retardant polyolefin materials of Comparative Examples 1 to 2 have good adhesion due to the adjustment of the addition amount of polyethylene and polypropylene, and more polypropylene is added. However, due to the rapid crystallization, the leaf shrinkage and deformation are serious, and the addition of more polyethylene will lead to a decrease in adhesion. Compared with the embodiments, the flame retardant polyolefin materials of Comparative Examples 3 to 4 have replaced the polyethylene / polypropylene model, and have not selected the high melt index model, which makes injection molding difficult, and the HP500N-Z scheme is used instead. Since HP500N-Z is a homopolymer polypropylene, it has low impact strength, poor toughness, and brittle leaf bones. Comparative Example 5 directly adds EPFR-110G without using flame retardant masterbatch. In the process of forming the resin, the flame retardant is unevenly dispersed, thereby reducing the adhesion of the polyolefin material. Compared with Example 1, the flame retardant polyolefin material of Comparative Example 6 replaces the base material of phosphorus nitrogen flame retardant masterbatch with polypropylene resin. Since the melting point of polypropylene resin is 165°C, the prepared flame retardant masterbatch is added to the twin-screw extruder from the side feed. Due to the short plasticization distance, the polypropylene is not completely plasticized and uniform, the impact strength is reduced, and the bonding effect is poor. It is further proved that the base material of the polyolefin material adopts high melt index polyethylene resin and high melt index polypropylene resin and makes both fully plasticized during the preparation process, which can improve the bonding effect and impact strength of the polyolefin material.

[0070] The above embodiments are preferred implementation modes of the present invention, but the implementation modes of the present invention are not limited to the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications that do not deviate from the spirit and principles of the present invention should be equivalent replacement methods and are included in the protection scope of the present invention.

Claims

1. A halogen-free flame-retardant polyolefin material, characterized in that: The invention comprises the following raw materials in parts by weight: 25 to 40 parts of polyethylene resin, 25 to 30 parts of polypropylene resin, 35 to 50 parts of phosphorus nitrogen flame retardant masterbatch, and 0.1 to 0.5 parts of antioxidant; the polyethylene resin has a melting index of 40 to 80 g / 10 min at a temperature of 190° C. and a load of 2.16 kg; the polypropylene resin has a melting index of 20 to 60 g / 10 min at a temperature of 230° C. and a load of 2.16 kg, and the cantilever beam impact strength is at least 300 J / m.

2. The halogen-free flame-retardant polyolefin material according to claim 1, characterized in that: The phosphorus-nitrogen flame retardant masterbatch comprises the following raw materials in parts by weight: 20 to 35 parts of polyethylene resin, 60 to 75 parts of phosphorus-nitrogen compound flame retardant, and 1 to 3 parts of lubricant polyethylene wax.

3. The halogen-free flame-retardant polyolefin material according to claim 2, characterized in that: The phosphorus-nitrogen composite flame retardant includes at least one of ammonium polyphosphate flame retardants and piperazine pyrophosphate flame retardants.

4. The halogen-free flame-retardant polyolefin material according to claim 1, characterized in that: The halogen-free flame-retardant polyolefin material further includes an anti-UV agent, and the anti-UV agent includes at least one of ultraviolet absorbers UV-770, UV-531, UV-284, UV-538, UV-234, UV-326 or UV-327.

5. The halogen-free flame-retardant polyolefin material according to claim 1, characterized in that: The halogen-free flame-retardant polyolefin material also includes a lubricant; the lubricant includes at least one of polyethylene glycol lubricants, fluorine-containing polymer lubricants, silicone lubricants, fatty alcohol lubricants, fatty acid lubricants, fatty acid ester lubricants, stearic acid amide lubricants, fatty acid metal soap lubricants, alkanes and oxidized alkanes lubricants or micro-nanoparticle lubricants.

6. The halogen-free flame-retardant polyolefin material according to claim 1, characterized in that: The halogen-free flame-retardant polyolefin material further includes an anti-drip agent; the anti-drip agent is polytetrafluoroethylene.

7. A method for preparing the halogen-free flame-retardant polyolefin material according to any one of claims 1 to 6, characterized in that: The following steps are involved: The raw materials for preparing the halogen-free flame-retardant polyolefin material are mixed, plasticized, extruded and pelletized to obtain the halogen-free flame-retardant polyolefin material.

8. The preparation method according to claim 7, characterized in that: The preparation method of the halogen-free flame-retardant polyolefin material comprises the following steps: mixing the other raw materials except the phosphorus-nitrogen flame-retardant masterbatch in the preparation raw materials of the halogen-free flame-retardant polyolefin material, feeding the raw materials from the main feed of a twin-screw extruder, feeding the nitrogen flame-retardant masterbatch from the side feed, plasticizing, extruding, cooling, drying and pelletizing in the twin-screw extruder to obtain the halogen-free flame-retardant polyolefin material.

9. An injection molding material, comprising the halogen-free flame-retardant polyolefin material according to any one of claims 1 to 6.

10. A simulated decorative item, made of the halogen-free flame-retardant polyolefin material according to any one of claims 1 to 6.

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