Flame-retardant enhanced special material for plastic tray as well as preparation method and application of flame-retardant enhanced special material

Abstract

The invention belongs to the technical field of high polymer material modification, and particularly relates to a flame-retardant reinforced plastic tray special material, in particular to a flame-retardant reinforced plastic tray special material for preparing a plastic tray through an injection molding process, and discloses a preparation method of the flame-retardant reinforced plastic tray special material. The invention relates to a special flame-retardant enhanced material for a plastic tray. The special flame-retardant enhanced material is prepared from HDPE (high-density polyethylene) resin, a flame retardant master batch, a polyethylene grafting material, thermosetting epoxy resin, a high-temperature curing agent, a normal-temperature curing agent, a curing accelerator, petroleum resin, talcum powder, a lubricant, an antioxidant and a light stabilizer as raw material systems through melt extrusion and granulation. The special material for the flame-retardant reinforced plastic tray not only has flame retardance, but also has good rigidity and toughness, especially has high elongation at break, and improves the bearing capacity and the application range of a common tray.

Description

Technical Field

[0001] The invention belongs to the technical field of polymer material modification, and specifically relates to a flame retardant reinforced plastic pallet special material, and in particular to a flame retardant reinforced plastic pallet special material used for preparing plastic pallets by injection molding process, and discloses a preparation method thereof. Background Art

[0002] Plastic pallets are the most commonly used modern circulation tools in the logistics industry. Compared with pallets made of other materials, plastic pallets have the advantages of light weight, moisture resistance, corrosion resistance, and long practical life, and have broader application prospects.

[0003] Traditional plastic pallet materials usually have unsatisfactory strength and flame retardant properties. Pallets are often used to carry heavy goods, so they are required to have good rigidity and toughness. However, the pallets produced by plastic materials suitable for pallet production on the market have insufficient bearing capacity, causing the pallets to deform or even break. In addition, traditional pallet materials do not have flame retardant properties and are easy to burn during use, which poses a great safety hazard. Therefore, the art expects to develop a new type of special material for plastic pallets to overcome the above defects.

[0004] At present, the reinforcement and modification processes of plastic materials mainly include blending modification, filling modification, cross-linking modification, etc. For example, Chinese patent CN104262987A discloses a high-strength modified plastic pallet, and the modified plastic components mainly include plastic raw materials, reinforcing fibers, glass fibers and other components and additives; but since the material contains fiber components, the elongation at break performance of the product will be seriously reduced, and the application range of the product will be affected. For another example, Chinese patent CN104479192A discloses a material for plastic pallets with high strength and good toughness, but the material also contains a high content of glass fibers, which seriously reduces the elongation at break performance of the product, and the application range of the product is also affected. For example, Chinese patent CN105348619A discloses a method for producing flame-retardant plastic pallets, which comprises mixing plastic particles, flame retardants, lubricants and coupling agents, granulating at low temperature to form flame-retardant masterbatch, mixing the flame-retardant masterbatch with plastic particles to form flame-retardant plastic particles, and injecting the flame-retardant plastic particles to obtain flame-retardant plastic pallets; however, this scheme is only to simply blend plastic particles with flame retardants and other additives to obtain flame-retardant plastic particles, and the strength and toughness of the prepared plastic pallets are not high. In addition, Chinese patent CN106832505A discloses a special material for plastic pallets and a preparation method thereof, which uses high-density polyethylene as the main raw material, optimizes the type and formula of raw materials, and scientifically compounding can significantly improve the impact resistance, high temperature resistance, antistatic, anti-shrinkage performance, relative tensile load, strength, toughness, elastic modulus and oxidation resistance of the special material for plastic pallets, and is easy to biodegrade and reduce production costs; however, the implementation process of this method is relatively complicated, difficult to control, and has high costs. In addition, Chinese patent CN116063772A discloses a modified polymer plastic pallet and a preparation method thereof, wherein linear low-density polyethylene, polypropylene, calcium stearate, fumaric pinamide, and nanocellulose are stirred and mixed in a high-speed mixer, extruded and granulated by a twin-screw extruder, and then the granules are fed into an injection molding machine for injection molding to obtain a modified polymer plastic pallet having high tensile strength and impact strength properties; however, since toxic and harmful solvents such as dichloromethane are used in the preparation of fumaric pinamide, the patented technology is difficult to promote and apply.

[0005] In summary, the art is looking forward to developing a special material for plastic pallets that can meet the requirements of the bearing capacity and flame retardant performance of plastic pallets, which has positive significance for the development and promotion of plastic pallets. Summary of the invention

[0006] Therefore, the technical problem to be solved by the present invention is to provide a flame retardant reinforced plastic pallet special material, which can effectively solve the problems of insufficient bearing capacity and lack of flame retardant performance of ordinary plastic pallets. The special material also has a longer elongation at break, better toughness and environmental protection, and expands the application range of the special material;

[0007] The second technical problem to be solved by the present invention is to provide a preparation method and application of the above-mentioned flame retardant reinforced plastic pallet special material.

[0008] In order to solve the above technical problems, the flame retardant reinforced plastic pallet special material described in the present invention comprises the following raw material components in parts by weight:

[0009] 100 parts by weight of HDPE resin;

[0010] 8-10 parts by weight of flame retardant masterbatch;

[0011] 5-8 parts by weight of polyethylene grafted material;

[0012] 10-18 parts by weight of thermosetting epoxy resin;

[0013] 8-14 parts by weight of high temperature curing agent;

[0014] 1-4 parts by weight of room temperature curing agent;

[0015] 0.5-2 parts by weight of curing accelerator;

[0016] 8-15 parts by weight of petroleum resin;

[0017] 8-10 parts by weight of talc;

[0018] Lubricant 0.5-1.5 parts by weight;

[0019] 0.3-1.5 parts by weight of antioxidant;

[0020] Light stabilizer 0.2-0.8 parts by weight;

[0021] Wherein, the HDPE resin comprises a mixture of a first HDPE resin and a second HDPE resin;

[0022] The first HDPE resin includes a copolymerized HDPE injection molding material whose comonomer is 1-butene or 1-hexene;

[0023] The second HDPE resin comprises a bimodal HDPE pipe material.

[0024] Specifically, in the flame-retardant enhanced plastic pallet special material, in the HDPE resin, the mass ratio of the first HDPE resin to the second HDPE resin is 25-45:55-75.

[0025] Specifically, the flame retardant reinforced plastic pallet special material, the first HDPE resin has a weight average molecular weight of 60,000-100,000, a molar fraction of the comonomer of 1.5-2.0%, and a density of 0.950-0.960 g / cm 3, melt mass flow rate (MFR) is 7.0-20.0g / 10min (190°C, 2.16kg), and the elongation at break is ≥800%.

[0026] Specifically, the density of the second HDPE resin of the flame retardant reinforced plastic pallet special material is 0.948-0.958 g / cm 3 , MFR is 0.3-2.5g / 10min (190℃, 5.0kg).

[0027] The special material for plastic pallets of the present invention adopts two kinds of HDPE, one is a first HDPE with high density, good fluidity and easy processing, and its main function is to ensure that the material has certain rigidity and melt fluidity, and the other is a second HDPE with bimodal molecular weight distribution and good comprehensive performance, and has relatively high filling property for inorganic rigid fillers and less influence on the tensile elongation at break performance of the material, and its main function is to improve the impact resistance of the material and the filling amount of the rigid filler. The combination of the two HDPE can ensure that the material has high rigidity and mechanical properties, especially high tensile elongation at break.

[0028] In the special material for plastic pallets of the present invention, the first HDPE resin includes a copolymerized HDPE injection molding material whose comonomer is 1-butene or 1-hexene, and whose weight average molecular weight is 60,000-100,000 and whose mole fraction of the comonomer is 1.5-2.0%. The addition of an appropriate amount of the comonomer can slightly reduce the crystallinity of the polymer and increase the branching degree, thereby reducing the density, which is beneficial to the improvement of the environmental stress cracking resistance and impact resistance of the polymer. The density is preferably 0.950-0.960 g / cm 3 , melt mass flow rate (MFR) is 7.0-20.0 g / 10 min (190°C, 2.16 kg), and the elongation at break is ≥800%.

[0029] In the special material for plastic pallets of the present invention, the second HDPE resin comprises a bimodal HDPE pipe material, preferably with a density of 0.948-0.958 g / cm 3 , MFR is 0.3-2.5g / 10min (190℃, 5.0kg).

[0030] Specifically, the flame retardant reinforced plastic pallet special material, the flame retardant includes polyethylene flame retardant masterbatch. The flame retardant used in the present invention is a white polyethylene flame retardant masterbatch, which is compounded with a variety of flame retardant components and then extruded and granulated together with a polyethylene carrier resin. It has the characteristics of good dispersibility, small addition amount, and strong flame retardant performance. It has been proved through multiple tests that only about 5% of the addition amount is added to the resin, and the flame retardancy of the resin can reach UL94-V2 level.

[0031] Specifically, the flame retardant reinforced plastic pallet special material, the polyethylene graft material includes high-density polyethylene grafted with maleic anhydride. The polyethylene graft material (PE-g-MAH) used in the present invention is high-density polyethylene grafted with maleic anhydride. The PE-g-MAH prepared with high-density polyethylene as the base material has the least effect on the rigidity of the material and can also increase the compatibility of various polar materials with polyethylene. The grafting rate is 0.8-1.5%.

[0032] Specifically, the flame retardant reinforced plastic pallet special material, the thermosetting epoxy resin includes a glycidylamine epoxy resin. The thermosetting epoxy resin used in the present invention is mainly a glycidylamine epoxy resin, which is a highly polar thermosetting resin, has a good affinity with the polar groups on the surface of the rigid particle filler, and can improve the dispersibility of the rigid particle filler. In addition, when co-extruded with plastics under high-temperature processing conditions, it can be in-situ cured to form rigid microspheres with small particle sizes under the synergistic effect of self-catalysis and containing curing agents and accelerators. At the same time, during the curing reaction, the epoxy groups of the epoxy resin react with the MAH groups of PE-g-MAH in the material to form hard cross-linking points, further improving the compatibility of the rigid microspheres and other rigid particle fillers formed after curing with polyethylene, and can achieve good dispersion in plastics, playing a role in rigid particle filling enhancement.

[0033] Specifically, for the flame-retardant reinforced plastic pallet material, the residence time of the epoxy resin during the high temperature (greater than 170°C) extrusion process of the twin-screw extruder is relatively short (3-5 minutes). To achieve in-situ curing, it is necessary that the curing system of the curing agent and the epoxy resin can achieve dynamic curing at the extrusion processing temperature and time.

[0034] Specifically, the flame retardant reinforced plastic pallet special material, the high temperature curing agent includes an anhydride curing agent. The curing accelerator used in the present invention is 2,4,6-tris(dimethylaminomethyl)phenol (DMP-30 accelerator), which can shorten the curing time of the curing system and improve the curing effect.

[0035] Specifically, the flame retardant reinforced plastic pallet special material, the room temperature curing agent includes at least one of a polyamide curing agent or an amine modified curing agent.

[0036] The flame retardant reinforced plastic pallet special material of the present invention adopts two curing agents, one is a high temperature curing agent, and the other is a room temperature curing agent; wherein, the high temperature curing agent adopts an anhydride curing agent, and the anhydride curing agent preferably adopts methyl nadic anhydride (MNA) with very low toxicity; the room temperature curing agent can be one or a mixture of polyamide curing agent and amine modified curing agent, and the toxicity of polyamide curing agent and amine modified curing agent are also low, and they belong to environmentally friendly materials. Methyl nadic anhydride can make most of the epoxy resin dynamically in situ cured in a short time during the twin-screw extrusion process under the condition of containing a curing accelerator and high temperature, and at the same time, in the mixed curing process participated by the amine curing agent, due to the amide reaction between the anhydride and the amine, more epoxy resin can be cured, and the curing effect is improved.

[0037] Specifically, the flame-retardant enhanced plastic pallet special material, the curing accelerator includes 2,4,6-tris(dimethylaminomethyl)phenol; the curing time of the curing system can be shortened and the curing effect can be improved.

[0038] Specifically, the flame retardant reinforced plastic pallet special material, the petroleum resin includes at least one of aliphatic hydrocarbon resin (C5 petroleum resin), aromatic hydrocarbon resin (C9 petroleum resin), C5 / C9 petroleum resin, dicyclopentadiene resin (DCPD petroleum resin) and modified resins thereof. The petroleum resin used in the present invention can be one or a mixture of aliphatic hydrocarbon resin (C5 petroleum resin), aromatic hydrocarbon resin (C9 petroleum resin), C5 / C9 petroleum resin, dicyclopentadiene resin (DCPD petroleum resin) and modified resins thereof, preferably hydrogenated modified C9 petroleum resin. Petroleum resin can increase the compatibility of polar materials with polyethylene, improve the cohesion and strength of the blend, and greatly improve the processing fluidity of the blend. The petroleum resin used in the present invention has a ring and ball softening point of 80-160°C.

[0039] Specifically, the flame retardant reinforced plastic pallet special material, the talcum powder includes hydrated magnesium silicate; the talcum powder used in the present invention is hydrated magnesium silicate, which may be activated by a surface treatment agent or may not be treated, and has a particle size of 1200-5000 mesh.

[0040] Specifically, the flame retardant reinforced plastic pallet special material, the lubricant includes at least one of stearic acid, calcium stearate, zinc stearate, barium stearate and ethylene bisstearamide (EBS).

[0041] Specifically, in the flame-retardant enhanced plastic pallet special material, the antioxidant includes at least one of a hindered phenol antioxidant or a phosphite antioxidant; preferably, the antioxidant used in the present invention is a compound of hindered phenol antioxidant 1010 and phosphite antioxidant 168, and the compounding ratio is 1:1-2:1.

[0042] Specifically, in the flame retardant reinforced plastic pallet special material, the light stabilizer includes at least one of a benzophenone light stabilizer or a hindered amine light stabilizer. Preferably, the light stabilizer is one or both of a benzophenone light stabilizer UV-531 and a hindered amine light stabilizer UV-770.

[0043] The present invention also discloses a method for preparing the flame retardant enhanced plastic pallet special material, comprising the following steps:

[0044] (1) taking selected amounts of the thermosetting epoxy resin, the high temperature curing agent, the room temperature curing agent and the curing accelerator and mixing them to obtain a first mixture;

[0045] (2) taking the first mixed material and mixing it with selected amounts of the HDPE resin, flame retardant masterbatch, polyethylene grafted material, petroleum resin, talcum powder, lubricant, antioxidant, and light stabilizer to obtain a second mixed material;

[0046] (3) The second mixed material is melt-extruded and granulated to obtain.

[0047] Specifically, the preparation method of the flame retardant reinforced plastic pallet special material is as follows:

[0048] In the step (1), the mixing step includes a step of high-speed stirring and mixing at a rotation speed of 2000-3000 rpm; and / or,

[0049] In the step (2), the mixing step includes a step of high-speed stirring and mixing at a rotation speed of 800-1200 rpm.

[0050] Specifically, in the method for preparing the flame-retardant reinforced plastic pallet special material, in the step (3), the temperature of the melt extrusion granulation step is 180-200°C;

[0051] Preferably, the melt extrusion granulation step uses a co-rotating twin-screw extruder.

[0052] The invention also discloses the use of the flame retardant enhanced plastic pallet special material for preparing plastic pallets.

[0053] The invention also discloses a flame retardant enhanced plastic pallet. The raw materials for preparing the plastic pallet include the special material for the flame retardant enhanced plastic pallet.

[0054] The flame retardant reinforced plastic pallet special material of the present invention is made of HDPE resin, flame retardant masterbatch, polyethylene grafted material, thermosetting epoxy resin, high temperature curing agent, room temperature curing agent, curing accelerator, petroleum resin, talcum powder, lubricant, antioxidant, light stabilizer as raw material system and is melt extruded and granulated. The flame retardant reinforced plastic pallet special material of the present invention not only has flame retardancy, but also has good rigidity and toughness, especially has a higher elongation at break, which improves the load-bearing capacity and scope of use of ordinary pallets. The raw materials used in the present invention are environmentally friendly and harmless, the preparation method is simple, and the processing operation is easy. The pallets prepared with the raw materials can be recycled and reused.

[0055] The flame-retardant reinforced plastic pallet special material of the present invention uses two high-density polyethylenes with different characteristics and properties as base materials, and utilizes the strong affinity between the strongly polar epoxy resin and talcum powder to improve the dispersion of the talcum powder. The rigid microspheres and talcum powder formed after the epoxy resin is in-situ cured jointly play a role in reinforcing the rigid particles, thereby improving the strength of the material. Meanwhile, the epoxy resin can react chemically with PE-g-MAH during the curing process, and the formed hard cross-linking points not only improve the binding force between the epoxy resin and PE-g-MAH, but also improve the compatibility of the hard cross-linking points with talcum powder and polyethylene, thereby improving the cohesion of the material. Meanwhile, the viscosity-increasing effect of petroleum resin is utilized to further improve the cohesion and strength of the material and the processing fluidity. The flame-retardant reinforced plastic pallet special material prepared by combining with flame retardants and other additives has good processing performance, mechanical properties and environmental protection.

[0056] The flame-retardant reinforced plastic pallet special material described in the present invention uses resin raw materials mainly composed of two high-density polyethylene (HDPE) resins with different characteristics and performances. The inorganic filler talcum powder with good rigidity enhancement effect is used to improve the rigidity, but too much use will seriously reduce the toughness of the material, especially the elongation at break performance, and too little use will not significantly improve the rigidity. Therefore, in order to further improve the rigidity of the material without seriously losing the toughness of the material, the present invention uses an in-situ curable thermosetting epoxy resin to further improve the rigidity of the material. Since the epoxy resin is a strong polar resin, it has a good affinity with the polar groups on the surface of the talcum powder. At the same time, when the epoxy resin undergoes a curing reaction during the extrusion process, it can also react with the polyethylene graft material added to the material to increase the compatibility of the polar material with polyethylene. The formed hard cross-linking points and talcum powder rigid particles are both improved in compatibility with polyethylene. Therefore, under the synergistic effect of the inorganic filler talcum powder, the in-situ curable epoxy resin organic material and the polyethylene graft material, the rigidity of the material can be greatly improved while the toughness of the material can be minimized. In addition, the present invention also adds a certain amount of petroleum resin to increase the melt fluidity of the material. The viscosity-increasing effect of the petroleum resin can further improve the cohesion of the material blends and also play a role in increasing the rigidity and toughness of the material. The above raw materials are combined with flame retardants, curing agents, curing accelerators, antioxidants, lubricants and other additives through extruder granulation to prepare flame retardant reinforced plastic pallet special materials.

[0057] The flame-retardant reinforced plastic pallet special material of the present invention uses two high-density polyethylene resins with different characteristics and properties to ensure that the material has certain rigidity and mechanical properties, especially a higher tensile elongation at break; talcum powder and epoxy resin that can be cured in situ into rigid microspheres are used as rigid reinforcement materials, which can greatly improve the rigidity of the pallet, and then combined with a compatibilizer polyethylene grafted material to reduce the loss of elongation at break of the pallet special material; the petroleum resin used can not only improve the cohesion and strength of the pallet special material, but also greatly improve the processing fluidity of the pallet special material. The flame-retardant reinforced plastic pallet special material of the present invention effectively solves the problems of insufficient bearing capacity and lack of flame retardant properties of ordinary plastic pallets. The raw materials used are environmentally friendly and harmless, the preparation method is simple, and the processing operation is easy. The pallets prepared with it can be recycled and reused. The special material also has a longer elongation at break, better toughness and environmental protection, which expands the application range of the special material. DETAILED DESCRIPTION

[0058] In order to better understand the present invention, the present invention is further described below in conjunction with the embodiments, the purpose is to better understand the content of the present invention. Therefore, the following embodiments are only illustrative and do not limit the scope of protection of the present invention. Those skilled in the art can make some non-essential improvements and adjustments to the present invention based on the contents of the present invention.

[0059] The components used in the following examples and comparative examples of the present invention are commercially available products.

[0060] As an exemplary embodiment, the raw material component information used in the following examples of the present invention includes:

[0061] The first HDPE resin is HDPE DMDA 8008 produced by PetroChina Daqing Petrochemical Company, with a density of 0.957g / cm 3 , MFR is 8.0g / 10min;

[0062] The second HDPE resin is HDPE PN049-030-122 produced by Sinopec Tianjin Petrochemical Company, with a density of 0.949 g / cm 3 , MFR is 0.3 / 10min;

[0063] The polyethylene flame retardant masterbatch is produced by Shandong Guoliang Environmental Protection Technology Co., Ltd.;

[0064] PE-g-MAH is E100 from DuPont (MFR is 2.0 g / 10 min, grafting rate is 1.2%);

[0065] The epoxy resin was glycidylamine epoxy resin (AG-80) produced by Shanghai Resin Research Institute;

[0066] The high temperature curing agent is methylnadic anhydride (MNA) produced by Shanghai Bangcheng Chemical Co., Ltd.;

[0067] The room temperature curing agent is an amine-modified curing agent (593) produced by Baling Petrochemical;

[0068] The curing accelerator is 2,4,6-tris(dimethylaminomethyl)phenol (DMP-30) produced by Changzhou Yijia New Material Technology Co., Ltd.

[0069] The petroleum resin is hydrogenated C9 petroleum resin (HPR-C9100) produced by Shandong Qilong Chemical Co., Ltd. (ring and ball softening point 95-135°C);

[0070] The talc powder is HM4 talc powder (mesh number is 2143) produced by IMIFABI, Italy;

[0071] The lubricant is zinc stearate produced by Zibo Xinsu Company;

[0072] The antioxidants are 1010 and 168 produced by Linyi Sanfeng Company, mixed in a 1:1 ratio;

[0073] The light stabilizer is a benzophenone light stabilizer (UV-531) produced by Nanjing Jingtianwei Chemical Co., Ltd.

[0074] Examples 1-5

[0075] In the schemes of Examples 1 to 5 of the present invention, the proportions of the various raw material components are shown in Table 1 below, and the proportions of each component are in parts by weight.

[0076] Table 1 Example formulation

[0077] raw material Example 1 Example 2 Example 3 Example 4 Example 5 First HDPE 36 25 32 45 38 Second HDPE 64 75 68 55 62 Flame retardant masterbatch 9 8 10 10 9 PE-g-MAH 7 5 6 8 6 Epoxy resin 16 10 14 17 18 High temperature curing agent 12 8 10.5 14 13 Room temperature curing agent 3 3 4 1 2 Accelerator 1.2 0.8 0.5 0.6 2 Petroleum resin 13 8 15 10 12 talcum powder 9 10 8 10 8 Lubricants 1.2 0.5 1.5 0.8 1.0 Antioxidants 0.5 0.3 0.8 1.5 0.8 Light Stabilizer 0.5 0.8 0.2 0.4 0.5

[0078] In the schemes of embodiments 1 to 5 of the present invention, the method for preparing the special material for plastic pallets comprises the following steps:

[0079] (1) weighing the epoxy resin, the high temperature curing agent, the low temperature curing agent and the curing accelerator according to the formula and mixing them uniformly in a high-speed mixer at room temperature for 5 minutes at a stirring speed of 2000 rpm to obtain a first mixture;

[0080] (2) taking the first mixed material and a selected amount of the HDPE resin, flame retardant masterbatch, polyethylene grafted material, petroleum resin, talcum powder (to be dried), lubricant, antioxidant, and light stabilizer, and mixing them in a high-speed mixer at room temperature for 15 minutes at a stirring speed of 1000 rpm to obtain a second mixed material;

[0081] (3) The second mixed material is placed in a co-rotating twin-screw extruder, melt-extruded and granulated at 180-200° C., and then dried and packaged to form a finished product.

[0082] Comparative Examples 1-6

[0083] In comparative examples 1 to 6 of the present invention, the proportions of the various raw material components are shown in Table 2 below, and the proportions of each component are in parts by weight.

[0084] Table 2 Comparative Example Formula

[0085] raw material Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 Comparative Example 6 First HDPE 100 / 39 36 36 41 Second HDPE / 100 68 64 64 72 Flame retardant masterbatch 9 9 9 9 9 9 PE-g-MAH 7 7 / 7 7 7 Epoxy resin 16 16 16 20.5 / 16 High temperature curing agent 12 12 12 15.5 / 12 Room temperature curing agent 3 3 3 4 / 3 Accelerator 1.2 1.2 1.2 1.2 / 1.2 Petroleum resin 13 13 13 13 13 / talcum powder 9 9 9 / 40 9 Lubricants 1.2 1.2 1.2 1.2 1.2 1.2 Antioxidants 0.5 0.5 0.5 0.5 0.5 0.5 Light Stabilizer 0.5 0.5 0.5 0.5 0.5 0.5

[0086] In Comparative Examples 1-6 of the present invention, the preparation method of the special material for plastic pallets is the same as that of the aforementioned Examples 1-5.

[0087] Experimental example

[0088] The special materials for plastic pallets prepared in the above-mentioned Examples 1-5 and Comparative Examples 1-6 were respectively taken and performance tests were carried out, wherein:

[0089] The tensile performance test standard is GB / T 1040, the specimen type is 1B, and the tensile speed is 50mm / min;

[0090] The bending performance test standard is GB / T 9341;

[0091] The test standard for simply supported beam notched impact strength (23°C) is GB / T 1043.1, and the notch type is Type A.

[0092] The test results of the special materials prepared by Examples 1-5 and Comparative Examples 1-6 are shown in Table 3.

[0093] Table 3 Special material performance test results

[0094]

[0095] It can be seen from the test results in Table 3 above that the special material for plastic pallets of the present invention uses two high-density polyethylene resins with different characteristics and properties to ensure that the material has certain rigidity and mechanical properties, especially a higher tensile elongation at break; and the use of talcum powder and epoxy resin that can be cured in situ into rigid microspheres as rigid reinforcement materials can greatly improve the rigidity of the pallet, and the loss of elongation at break of the special material for pallets can be reduced by combining with the compatibilizer polyethylene grafted material; the petroleum resin used can not only improve the cohesion and strength of the special material for pallets, but also greatly improve the processing fluidity of the special material for pallets. It can be seen that the flame-retardant reinforced plastic pallet special material prepared by the present invention not only has flame retardancy, but also has good rigidity and toughness, especially has a higher elongation at break, which improves the carrying capacity and scope of use of the pallet.

[0096] It can be seen from the test results in Table 3 above that the special material prepared by using only HDPE1 injection molding material as the base resin in Comparative Example 1 has poor toughness, especially the elongation at break performance; while the special material prepared by using only HDPE2 pipe material as the base resin in Comparative Example 2 also has good mechanical properties, but the special material is difficult to extrude during the extrusion process and has poor fluidity, so it is not suitable for injection molding pallets. This also fully proves that the combination of two HDPE special materials in the present invention shows good synergy.

[0097] According to the test results in Table 3 above, the comprehensive performance of the special material prepared without grafting material in the formula of Comparative Example 3 is greatly reduced; the comprehensive performance of the special material prepared with only one rigid reinforcement material in the formula of Comparative Example 4 and Comparative Example 5 is also greatly reduced; and the comprehensive performance of the special material prepared without petroleum resin in the formula of Comparative Example 6 is also slightly reduced, and it is found that the processing fluidity of the composition is also low, it is difficult to extrude and process, and it is not suitable for preparing trays by injection molding process. This also fully proves that the present invention uses two different types of rigid reinforcement materials with good synergistic effect.

[0098] In summary, the flame retardant reinforced plastic pallet material prepared by the present invention not only has flame retardancy, but also has good rigidity and toughness, especially has a higher elongation at break, thereby improving the load-bearing capacity and application range of the pallet.

[0099] The embodiments of the present invention are described in detail above. Specific examples are used herein to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method of the present invention and its core idea. At the same time, for those skilled in the art, according to the idea of ​​the present invention, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. A flame retardant reinforced plastic pallet special material, characterized in that: The raw material components include the following parts by weight: 100 parts by weight of HDPE resin; 8-10 parts by weight of flame retardant masterbatch; 5-8 parts by weight of polyethylene grafted material; 10-18 parts by weight of thermosetting epoxy resin; 8-14 parts by weight of high temperature curing agent; 1-4 parts by weight of room temperature curing agent; 0.5-2 parts by weight of curing accelerator; 8-15 parts by weight of petroleum resin; 8-10 parts by weight of talc; Lubricant 0.5-1.5 parts by weight; 0.3-1.5 parts by weight of antioxidant; Light stabilizer 0.2-0.8 parts by weight; Wherein, the HDPE resin comprises a mixture of a first HDPE resin and a second HDPE resin; The first HDPE resin includes a copolymerized HDPE injection molding material whose comonomer is 1-butene or 1-hexene; The second HDPE resin comprises a bimodal HDPE pipe material.

2. The flame retardant reinforced plastic pallet material according to claim 1 is characterized in that: In the HDPE resin, the mass ratio of the first HDPE resin to the second HDPE resin is 25-45:55-75.

3. The flame retardant reinforced plastic pallet material according to claim 1 or 2, characterized in that: The weight average molecular weight of the first HDPE resin is 60,000-100,000, the molar fraction of the comonomer is 1.5-2.0%, and the density is 0.950-0.960 g / cm 3 , melt mass flow rate (MFR) is 7.0-20.0g / 10min (190°C, 2.16kg), and the elongation at break is ≥800%.

4. The flame retardant reinforced plastic pallet material according to claim 1 or 2, characterized in that: The density of the second HDPE resin is 0.948-0.958 g / cm 3 , MFR is 0.3-2.5g / 10min (190℃, 5.0kg).

5. The flame retardant reinforced plastic pallet material according to any one of claims 1 to 4, characterized in that: The flame retardant comprises a polyethylene flame retardant masterbatch; and / or, The polyethylene graft material comprises high-density polyethylene grafted with maleic anhydride; and / or, The thermosetting epoxy resin includes a glycidylamine type epoxy resin; and / or, The high temperature curing agent includes an anhydride curing agent; and / or, The room temperature curing agent includes at least one of a polyamide curing agent or an amine modified curing agent; and / or, The curing accelerator includes 2,4,6-tris(dimethylaminomethyl)phenol; and / or, The petroleum resin includes at least one of aliphatic hydrocarbon resin (C5 petroleum resin), aromatic hydrocarbon resin (C9 petroleum resin), C5 / C9 petroleum resin, dicyclopentadiene resin (DCPD petroleum resin) and modified resins thereof; and / or, The talc comprises hydrated magnesium silicate; and / or, The lubricant comprises at least one of stearic acid, calcium stearate, zinc stearate, barium stearate and ethylene bis stearamide (EBS); and / or, The antioxidant comprises at least one of a hindered phenol antioxidant or a phosphite antioxidant; and / or, The light stabilizer includes at least one of a benzophenone light stabilizer or a hindered amine light stabilizer.

6. A method for preparing the flame retardant reinforced plastic pallet material according to any one of claims 1 to 5, characterized in that: The steps include: (1) taking selected amounts of the thermosetting epoxy resin, the high temperature curing agent, the room temperature curing agent and the curing accelerator and mixing them to obtain a first mixture; (2) taking the first mixed material and mixing it with selected amounts of the HDPE resin, flame retardant masterbatch, polyethylene grafted material, petroleum resin, talcum powder, lubricant, antioxidant, and light stabilizer to obtain a second mixed material; (3) The second mixed material is melt-extruded and granulated to obtain.

7. The method for preparing the flame retardant reinforced plastic pallet material according to claim 6, characterized in that: In the step (1), the mixing step includes a step of high-speed stirring and mixing at a rotation speed of 2000-3000 rpm; and / or, In the step (2), the mixing step includes a step of high-speed stirring and mixing at a rotation speed of 800-1200 rpm.

8. The method for preparing the flame retardant reinforced plastic pallet material according to claim 6 or 7, characterized in that: In the step (3), the temperature of the melt extrusion granulation step is 180-200°C; Preferably, the melt extrusion granulation step uses a co-rotating twin-screw extruder.

9. Use of the flame retardant reinforced plastic pallet material according to any one of claims 1 to 5 for preparing plastic pallets.

10. A flame retardant reinforced plastic pallet, characterized in that: The raw materials for preparing the plastic pallet include the flame retardant reinforced plastic pallet special material as described in any one of claims 1-5.

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