A kind of element-free rubber plastic material and its preparation method

Abstract

The application provides an element-sabium-free rubber and plastic material and a preparation method thereof, and belongs to the technical field of foaming rubber and plastic materials.The rubber and plastic material comprises the following components: nitrile rubber, polyvinyl chloride, chlorinated polyethylene, chlorinated paraffin, epoxy soybean oil, aluminum hydroxide, light calcium carbonate, a foaming agent, a foaming aid, carbon black, a compound flame retardant, a flame retardant synergist, solid paraffin, stearic acid, polyethylene glycol, sulfur, an antioxidant and a vulcanization accelerator.The element-sabium-free rubber and plastic product is prepared by adjusting the composition and ratio of raw materials, and the complete replacement of antimony trioxide is realized under the premise of ensuring the flame-retardant safety of the product.

Description

Technical Field

[0001] This invention relates to the field of foamed rubber and plastic materials technology, specifically to an antimony-free rubber and plastic material and its preparation method. Background Technology

[0002] NBR / PVC foam materials are widely used due to their low density and low thermal conductivity, resulting in excellent flexibility, cushioning, compressibility, elasticity, oil and chemical resistance, plasticity, weather resistance, and insulation. However, NBR / PVC foam materials have poor flame retardancy. During combustion, they generate a large amount of heat, accelerating the spread of fire and producing large amounts of smoke and toxic gases, endangering human health. Furthermore, the processing of NBR / PVC foam materials typically requires the addition of large amounts of fillers and plasticizers, further reducing their flame retardancy. In other words, while NBR / PVC foam materials contribute to my country's technological development, they also pose a potential fire hazard. Therefore, improving the fire safety of NBR / PVC foam materials and endowing them with flame retardant properties is crucial.

[0003] Currently, there are many types of materials used to improve flame retardant performance. They are generally classified into additive flame retardants and reactive flame retardants based on the relationship between the flame retardant and the flame-retarded material. Reactive flame retardants involve bonding flame-retardant elements or groups as monomers into the material, typically having minimal impact on the material's inherent properties while still achieving a flame-retardant effect. Additive flame retardants, on the other hand, are directly mixed with the material, offering convenient application, wide applicability, and advantages such as low cost, ease of operation, and successful industrialization. They are currently the main research direction for NBR / PVC flame retardancy. Additive flame retardants are generally classified into filler-type flame retardants, halogen-based flame retardants, phosphorus-based flame retardants, and nitrogen-based halogen-free flame retardants. Currently, the most commonly used flame retardants in NBR / PVC foam material processing are filler-type flame retardants, mainly referring to antimony trioxide, magnesium hydroxide, and aluminum hydroxide. During combustion, these promote esterification of the polymer molecular chains, forming a dense char layer on the material surface, thus achieving a flame-retardant effect. However, with the increasing market demand for antimony trioxide, the gradual depletion of raw material antimony ore resources, and the increasing requirements for environmental protection, the price of antimony trioxide has gradually risen, seriously affecting the cost of NBR / PVC products. Therefore, the research and development of new flame retardant systems has gradually become the research and development focus of NBR / PVC rubber and plastic thermal insulation materials.

[0004] Besides antimony trioxide, other commonly used flame retardants include halogenated, phosphorus-based, and nitrogen-based flame retardants. Zinc borate is also a filler-type flame retardant that has been widely studied in recent years. Selecting suitable flame retardants for compounding to prepare highly flame-retardant rubber-plastic insulation materials and conducting industrial research on them is essential and of significant practical importance. Therefore, it is necessary to provide an antimony-free rubber-plastic material and its preparation method to overcome the problems existing in the current technology. Summary of the Invention

[0005] In view of this, the present invention provides an antimony-free rubber and plastic material and its preparation method. The present invention achieves the preparation of antimony-free rubber and plastic products by using a specific compound flame retardant and flame retardant synergist, combined with a specific preparation process, thereby ensuring the flame retardant safety of the product and achieving a complete replacement of antimony trioxide.

[0006] This invention provides an antimony-free rubber and plastic material, comprising the following components by weight:

[0007] The composition includes: 7-15 parts nitrile rubber, 6-10 parts polyvinyl chloride, 5-9 parts chlorinated polyethylene, 15-19 parts chlorinated paraffin, 0.7-1.2 parts epoxidized soybean oil, 17-20 parts aluminum hydroxide, 6-10 parts light calcium carbonate, 9-15 parts foaming agent, 4.5-8 parts foaming aid, 1.1-1.7 parts carbon black, 4.5-6.8 parts compound flame retardant, 2.7-4.5 parts flame retardant synergist, 0.5-1 part solid paraffin, 0.15-0.5 parts stearic acid, 0.3-0.6 parts polyethylene glycol, 0.2-0.5 parts sulfur, 0.05-0.08 parts antioxidant, and 0.8-2 parts vulcanization accelerator.

[0008] Furthermore, the compound flame retardant includes at least one of phosphorus-based flame retardants and nitrogen-based flame retardants. Preferably, the mass ratio of phosphorus-based flame retardant to nitrogen-based flame retardant in the compound flame retardant is 2 to 3:1.

[0009] Furthermore, the flame retardant synergist is any one of expandable graphite, pentaerythritol, and zinc borate. Preferably, the mass ratio of expandable graphite, pentaerythritol, and zinc borate is 4:25:10.

[0010] Furthermore, the mass ratio of the compound flame retardant to the flame retardant synergist is 1.5~2.5:1.

[0011] Furthermore, the foaming agent is AC foaming agent, and the foaming aid is one or more of urea ester, adipic acid, and salicylic acid. Preferably, the foaming aid is urea ester.

[0012] Furthermore, the antioxidant is antioxidant 4020, and the vulcanization accelerator is one or more of accelerator ZBEC and accelerator TBzTD. Preferably, the vulcanization accelerator is accelerator ZBEC.

[0013] The present invention also provides a method for preparing the antimony-free rubber and plastic material, comprising the following steps:

[0014] S1. Nitrile rubber, polyvinyl chloride, chlorinated polyethylene, epoxidized soybean oil, light calcium carbonate, carbon black, compound flame retardant, flame retardant synergist, solid paraffin wax, stearic acid, polyethylene glycol, and antioxidant are put into a mixing equipment and mixed. Then, the first part of aluminum hydroxide and the first part of chlorinated paraffin wax are added for a first mixing. Then, the second part of aluminum hydroxide and the second part of chlorinated paraffin wax are added for a second mixing. After the rubber is mixed, the rubber is discharged, sliced ​​after open milling, cooled and allowed to stand to obtain material No. 1.

[0015] S2. Add sulfur, vulcanization accelerator, foaming agent and foaming aid to material No. 1, mix evenly after open milling, and then slice to obtain material No. 2;

[0016] S3. The No. 2 material is extruded through an extruder to obtain molding compound. After the molding compound is freely foamed and cooled, antimony-free rubber and plastic products are obtained.

[0017] Furthermore, in step S1, the mass ratio of the first part of aluminum hydroxide to the second part of aluminum hydroxide is 1:1, and the mass ratio of the first part of chlorinated paraffin to the second part of chlorinated paraffin is 2:1.

[0018] Furthermore, in step S1, the temperature of the first mixing is 135°C and the mixing time is 2-3 minutes, while the temperature of the second mixing is 155°C and the mixing time is 7-9 minutes.

[0019] Furthermore, the glue discharge temperature in step S1 is 168℃~175℃, preferably 168℃.

[0020] Furthermore, in step S3, the temperature of the feeding section of the extruder is 30℃~38℃, the temperature of the plasticizing section is 35℃~40℃, the temperature of the die head section is 40℃~45℃, the die head pressure is 0.4~0.5MPa, and the rotation speed is 14~18 r / min.

[0021] Furthermore, the foaming process described in step S3 is carried out in a foaming furnace, which is divided into seven or six temperature control zones. Preferably, the foaming furnace is divided into six temperature control zones, and the temperature settings of each zone are as follows: Zone 1 110℃~130℃, Zone 2 115℃~135℃, Zone 3 130℃~140℃, Zone 4 140℃~150℃, Zone 5 150℃~170℃, Zone 6 165℃~180℃. The initial conveying speed of Zone 1 of the foaming furnace is 1.0~1.4 m / min.

[0022] Furthermore, the thickness of the No. 1 material film is 8~9 mm, preferably, the thickness of the No. 1 material film is 8 mm.

[0023] Furthermore, the thickness of the No. 2 material film is 9~10 mm, preferably, the thickness of the No. 2 material film is 9 mm.

[0024] Furthermore, the cooling method described in step S3 is air cooling, and the cooling distance is 100 m.

[0025] Furthermore, step S3, after cooling, also includes cutting and packaging steps.

[0026] The antimony-free rubber and plastic materials prepared by this invention have a wide range of applications, including but not limited to the preparation of conventional thermal insulation materials, sound insulation materials, and shock-absorbing materials.

[0027] Compared with the prior art, the present invention has the following beneficial effects:

[0028] The main flame retardant of this invention is a phosphorus-nitrogen-based flame retardant. By adjusting the composition and ratio of raw materials and combining it with the use of flame retardant synergists, this invention achieves the preparation of antimony-free rubber and plastic products, and achieves complete replacement of antimony trioxide while ensuring the flame retardant safety of the products. Detailed Implementation

[0029] This invention provides an antimony-free rubber and plastic material, comprising the following components by weight:

[0030] The composition includes: 7-15 parts nitrile rubber, 6-10 parts polyvinyl chloride, 5-9 parts chlorinated polyethylene, 15-19 parts chlorinated paraffin, 0.7-1.2 parts epoxidized soybean oil, 17-20 parts aluminum hydroxide, 6-10 parts light calcium carbonate, 9-15 parts foaming agent, 4.5-8 parts foaming aid, 1.1-1.7 parts carbon black, 4.5-6.8 parts compound flame retardant, 2.7-4.5 parts flame retardant synergist, 0.5-1 part solid paraffin, 0.15-0.5 parts stearic acid, 0.3-0.6 parts polyethylene glycol, 0.2-0.5 parts sulfur, 0.05-0.08 parts antioxidant, and 0.8-2 parts vulcanization accelerator.

[0031] Nitrile rubber (NBR) is the main material in rubber-plastic composites, possessing excellent oil resistance. Polyvinyl chloride (PVC) enhances the stability, abrasion resistance, and aging resistance of materials; when combined with NBR, it combines the elasticity of rubber with the processing stability of plastics. Chlorinated polyethylene (CPE) is primarily used as a toughening agent, flame retardant, and impact modifier; by blending with materials such as PVC, it significantly improves the weather resistance, flame retardancy, and low-temperature performance of composite rubber-plastic materials. Chlorinated paraffin acts as a plasticizer, improving the flexibility and processing performance of rubber. Epoxidized soybean oil, as a plasticizer... Plasticizers and softeners improve the processing and physical properties of rubber; aluminum hydroxide is a flame retardant and filler; light calcium carbonate is a filler that reduces thermal conductivity; carbon black is a reinforcing agent; solid paraffin is a physical antioxidant and mold release agent; stearic acid has softening and plasticizing effects; polyethylene glycol is used as an internal mold release agent and vulcanization activator; sulfur is the most commonly used vulcanizing agent in the rubber industry. It reacts with the double bonds in the rubber molecular chain to form disulfide bonds (-CSC-), transforming linear rubber into a network molecular structure, thereby significantly improving the performance of the rubber.

[0032] Preferably, the antimony-free rubber-plastic material comprises, by weight, the following components: 13 parts nitrile rubber, 7 parts polyvinyl chloride, 6 parts chlorinated polyethylene, 16 parts chlorinated paraffin, 0.7 parts epoxidized soybean oil, 20 parts aluminum hydroxide, 8.7 parts light calcium carbonate, 10 parts foaming agent, 5 parts foaming aid, 1.3 parts carbon black, 5.4 parts compound flame retardant, 3.6 parts flame retardant synergist, 0.7 parts solid paraffin, 0.39 parts stearic acid, 0.35 parts polyethylene glycol, 0.5 parts sulfur, 0.06 parts antioxidant, and 1.3 parts vulcanization accelerator.

[0033] In some embodiments of the present invention, the compound flame retardant includes a single compound or compound system of phosphorus-based flame retardant and nitrogen-based flame retardant. The phosphorus-based flame retardant includes, but is not limited to, any one of ammonium polyphosphate, aluminum hypophosphite, polyphosphate, phosphate ester, phosphazene compound, phosphonic acid, and phosphonate. The nitrogen-based flame retardant includes, but is not limited to, any one of melamine, melamine cyanuric acid, and its derivatives. The compound system includes, but is not limited to, any one of ammonium polyphosphate-based compound system and phosphonate compound system. Preferably, the phosphorus-nitrogen flame retardant is a compound system of ammonium polyphosphate and melamine. Preferably, the compound system of ammonium polyphosphate and melamine is prepared by compounding ammonium polyphosphate and melamine at a mass ratio of 2:1.

[0034] Phosphorus-based flame retardants (such as phosphate esters and ammonium polyphosphate APP) decompose at high temperatures to generate polyphosphoric acid (Hn+2PnO3n+1). Polyphosphoric acid is a strong dehydrating agent, which can promote the dehydration and carbonization of hydroxyl (-OH), amino (-NH2) and other groups in the material to form a dense and porous carbon layer. This carbon layer has excellent heat insulation (preventing heat from being transferred to the interior) and barrier properties (isolating oxygen and combustible gases), which is the core function of phosphorus-based flame retardants.

[0035] Nitrogen-based flame retardants decompose rapidly at high temperatures, releasing large amounts of inert gases such as N2, CO2, and NH3. These gases do not participate in combustion and can dilute the concentration of combustible gases (such as methane and formaldehyde) and oxygen produced by the decomposition of materials, preventing the mixed gas from reaching the conditions for combustion.

[0036] Nitrogen compounds (such as melamine derivatives) produced by the decomposition of nitrogen-based flame retardants can react with the decomposition products of phosphorus-based flame retardants (such as polyphosphoric acid) to form a "phosphorus-nitrogen-carbon" composite carbon layer, which improves the density of the carbon layer. At the same time, the presence of nitrogen can suppress the amount of smoke generated during the combustion of materials (reducing the generation of carbon black particles).

[0037] Pentaerythritol undergoes an esterification reaction with polyphosphoric acid produced by the decomposition of phosphorus and nitrogen systems, rapidly dehydrating and crosslinking to form a dense and stable aromatic cyclic carbon layer. This fills the pore defects in rubber and plastic foam materials, constructing a highly efficient physical barrier layer. Phosphorus is anchored in the carbon layer through phosphorus-oxygen-carbon covalent bonds, reducing the volatilization loss of phosphorus-containing substances and improving phosphorus utilization efficiency. The water vapor released during the dehydration process works synergistically with inert gases such as NH3 and CO2 from the decomposition of phosphorus and nitrogen systems to reduce the oxygen concentration and combustible gas concentration in the combustion zone.

[0038] Expandable graphite rapidly expands at high temperatures to form a worm-like structure with a large specific surface area and porosity. It can coat the surface of rubber and plastic foam materials, forming a dense physical barrier layer that prevents heat transfer into the material and hinders the escape of combustible gases, thus inhibiting combustion. Ammonium polyphosphate (APP) in phosphorus-nitrogen flame retardants acts as an acid source, releasing acidic substances such as phosphoric acid when heated. These acidic substances can undergo esterification with pentaerythritol, promoting its dehydration and char formation. Expandable graphite works synergistically with APP and pentaerythritol; the polyphosphoric acid and phosphate compounds produced by the decomposition of APP promote the transformation of the graphite's worm-like structure into a denser char layer, enhancing the stability and thermal insulation performance of the char layer. Furthermore, the char layer formed by the deesterification and charring of pentaerythritol synergistically enhances the quality and flame-retardant effect of the char layer. Expandable graphite releases gases during expansion. These gases, along with inert gases such as ammonia (NH3) and carbon dioxide (CO2) produced by the decomposition of phosphorus-nitrogen flame retardants, dilute the oxygen concentration in the combustion zone and reduce the concentration of combustible gases, thereby inhibiting the combustion reaction. Furthermore, expandable graphite also has a certain smoke-suppressing effect; it can adsorb and capture smoke particles generated during combustion, reducing smoke release.

[0039] Zinc borate (common molecular formula 2ZnO·3B2O3·3.5H2O) is a typical inorganic flame retardant synergist. It has relatively weak flame retardancy itself, but it can significantly improve flame retardant efficiency and optimize flame retardant performance in phosphorus-based and nitrogen-based flame retardant systems through "synergistic effect".

[0040] While polyphosphoric acid, generated by phosphorus-based flame retardants, can catalyze carbonization, the carbonized layer may exhibit porous and loose characteristics when used alone, making it susceptible to penetration by high-temperature gases. Zinc borate decomposes at high temperatures to form B2O3 (boron oxide) and ZnO (zinc oxide). B2O3, a glassy substance, forms a "phosphorus-boron composite glass phase" with polyphosphoric acid, filling the pores of the carbonized layer and making it denser and more continuous. ZnO acts as an "inorganic filler," uniformly dispersed within the carbonized layer, enhancing its mechanical strength and preventing cracking or detachment at high temperatures, further strengthening its physical barrier properties. When zinc borate and phosphorus-based flame retardants work synergistically, the resulting "phosphorus-boron composite carbonized layer" adheres to the surface of molten material, inhibiting dripping. Simultaneously, the glassy properties of B2O3 can "encapsulate" the molten resin, preventing its flow and reducing the risk of reignition at its source.

[0041] The carbonized layer formed by nitrogen-based flame retardants alone (such as the cyanuric anhydride carbonized layer generated from the decomposition of melamine) is usually thin, has poor toughness, and is easily decomposed at high temperatures. B2O3 from the decomposition of zinc borate can chemically react with nitrogen-based decomposition products (such as amino and cyano groups) to form a "nitrogen-boron cross-linked structure" (such as borate amine compounds). This structure can significantly improve the thickness and thermal stability of the carbonized layer. On the one hand, the "physical insulation" ability of the composite carbonized layer far exceeds that of a single nitrogen-based carbonized layer, effectively preventing heat and gas transfer; on the other hand, the glassy properties of B2O3 can "bond" carbonized layer fragments, preventing them from falling off and extending the flame-retardant effect.

[0042] Nitrogen-based flame retardants tend to produce nitrogen-containing smog (such as NOx and cyanide smog) during combustion, and the smoke density is relatively high, which is their main drawback. Zinc borate's smoke-suppressing effect in this system is mainly achieved through two points: B2O3 can react with nitrogen-containing active groups in the smoke (such as -NH2, -CN) to generate stable boron-carbon compounds (such as BN), reducing the release of toxic nitrogen-containing gases; ZnO, as a "smoke inhibitor," can catalyze the oxidation of carbon particles (converting carbon particles into CO2), while simultaneously adsorbing tar and particulate matter in the smoke, significantly reducing smoke density.

[0043] The addition of flame retardant synergists can improve the mechanical properties of rubber and plastic foam materials to a certain extent. It can be uniformly dispersed in the material, acting as a filler and reinforcement, improving the tensile strength, elongation at break, and other mechanical properties, allowing the material to maintain good physical properties while being flame retardant.

[0044] In some embodiments of the present invention, the compound flame retardant is a combination of a phosphorus-based flame retardant and a nitrogen-based flame retardant. Preferably, the mass ratio of the phosphorus-based flame retardant to the nitrogen-based flame retardant in the compound flame retardant is 2 to 3:1.

[0045] In some embodiments of the present invention, the flame retardant synergist is any one of expandable graphite, pentaerythritol, and zinc borate. Preferably, the mass ratio of expandable graphite, pentaerythritol, and zinc borate is 4:25:10.

[0046] In some embodiments of the present invention, the mass ratio of the compound flame retardant to the flame retardant synergist is 1.5 to 2.5:1.

[0047] In some embodiments of the present invention, the foaming agent is AC foaming agent, and the foaming aid is one or more of urea ester, adipic acid, and salicylic acid. Preferably, the foaming aid is urea ester.

[0048] In some embodiments of the present invention, the antioxidant is antioxidant 4020, and the vulcanization accelerator is one or more of accelerator ZBEC (zinc dibenzyl dithiocarbamate) and accelerator TBzTD (tetrabenzyl thiuramized disulfide). Preferably, the vulcanization accelerator is accelerator ZBEC.

[0049] This invention uses phosphorus-nitrogen flame retardants as the main flame retardant components and flame retardant synergists as auxiliary flame retardant components, combined with the use of antioxidants and other additives. Under the premise of ensuring the good comprehensive performance of rubber and plastic foam materials, it realizes the preparation of antimony-free rubber and plastic materials, so that rubber and plastic foam materials still have good flame retardancy and good physical properties without the use of antimony trioxide.

[0050] The present invention also provides a method for preparing the antimony-free rubber and plastic material, comprising the following steps:

[0051] S1. Nitrile rubber, polyvinyl chloride, chlorinated polyethylene, epoxidized soybean oil, light calcium carbonate, carbon black, compound flame retardant, flame retardant synergist, solid paraffin wax, stearic acid, polyethylene glycol, and antioxidant are put into a mixing equipment and mixed. Then, the first part of aluminum hydroxide and the first part of chlorinated paraffin wax are added for a first mixing. Then, the second part of aluminum hydroxide and the second part of chlorinated paraffin wax are added for a second mixing. After the rubber is mixed, the rubber is discharged, sliced ​​after open milling, cooled and allowed to stand to obtain material No. 1.

[0052] S2. Add sulfur, vulcanization accelerator, foaming agent and foaming aid to material No. 1, mix evenly after open milling, and then slice to obtain material No. 2;

[0053] S3. The No. 2 material is extruded through an extruder to obtain molding compound. After the molding compound is freely foamed and cooled, antimony-free rubber and plastic products are obtained.

[0054] In some embodiments of the present invention, in step S1, the mass ratio of the first part of aluminum hydroxide to the second part of aluminum hydroxide is 1:1, and the mass ratio of the first part of chlorinated paraffin to the second part of chlorinated paraffin is 2:1.

[0055] In some embodiments of the present invention, the temperature of the first mixing step S1 is 135°C and the mixing time is 2-3 min, and the temperature of the second mixing step is 155°C and the mixing time is 7-9 min.

[0056] In some embodiments of the present invention, the glue discharge temperature in step S1 is 168°C to 175°C, preferably 168°C.

[0057] In some embodiments of the present invention, the temperature of the feeding section of the extruder in step S3 is 30℃~38℃, the temperature of the plasticizing section is 35℃~40℃, the temperature of the die head section is 40℃~45℃, the die head pressure is 0.4~0.5MPa, and the rotation speed is 14~18 r / min.

[0058] In some embodiments of the present invention, the foaming in step S3 is carried out in a foaming furnace, which is divided into seven-zone control or six-zone control according to temperature. Preferably, the foaming furnace is divided into six-zone control according to temperature.

[0059] In some embodiments of the present invention, the temperature settings of each zone of the foaming oven are as follows: Zone 1 110℃~130℃, Zone 2 115℃~135℃, Zone 3 130℃~140℃, Zone 4 140℃~150℃, Zone 5 150℃~170℃, and Zone 6 165℃~180℃.

[0060] In some embodiments of the present invention, the initial conveying speed of zone one of the foaming furnace is 1.0~1.4 m / min, and the linear speed of the remaining zones is adjusted according to the foaming conditions. This invention only limits the initial conveying speed of zone one of the foaming furnace, and does not limit the conveying speed of the subsequent zones. In actual production, the foaming conditions of materials vary due to factors such as raw material composition and proportions. Therefore, the temperature and conveying speed of each zone need to be flexibly adjusted according to the actual foaming conditions to ensure the foaming quality and dimensional stability of the material. Optimization and adjustment based on actual conditions can also improve the adaptability and flexibility of the process, adapting to different production needs.

[0061] In some embodiments of the present invention, the thickness of the No. 1 material film is 8-9 mm, preferably, the thickness of the No. 1 material film is 8 mm.

[0062] In some embodiments of the present invention, the thickness of the No. 2 material film is 9-10 mm, preferably, the thickness of the No. 2 material film is 9 mm.

[0063] In some embodiments of the present invention, the cooling method in step S3 is air cooling, and the cooling distance is 100 m.

[0064] In some embodiments of the present invention, step S3, after cooling, further includes cutting and packaging steps.

[0065] The antimony-free rubber and plastic materials prepared by this invention have a wide range of applications, including but not limited to the preparation of conventional thermal insulation materials, sound insulation materials, and shock-absorbing materials.

[0066] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of this invention, and not all of them. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0067] Unless otherwise specified, the test methods or experimental methods described in the following examples are all conventional methods; unless otherwise specified, the raw materials and additives are obtained from conventional commercial sources or prepared by conventional methods.

[0068] The phosphorus-nitrogen flame retardants in the following examples or comparative examples are compounded from ammonium polyphosphate and melamine in a mass ratio of 2:1.

[0069] Example 1

[0070] An antimony-free rubber-plastic material, with the following specific components by weight:

[0071] The composition includes: 12 parts nitrile rubber, 8 parts polyvinyl chloride, 7 parts chlorinated polyethylene, 15 parts chlorinated paraffin, 1 part epoxidized soybean oil, 19 parts aluminum hydroxide, 7.5 parts light calcium carbonate, 12.5 parts AC foaming agent, 6 parts urea ester, 1.3 parts carbon black, 5.4 parts compound flame retardant, 2.7 parts flame retardant synergist, 0.5 parts solid paraffin, 0.3 parts stearic acid, 0.35 parts polyethylene glycol, 0.4 parts sulfur, 0.05 parts antioxidant 4020, and 1 part vulcanization accelerator ZBEC.

[0072] The mass ratio of the compound flame retardant to the flame retardant synergist is 2:1.

[0073] The preparation method of the antimony-free rubber and plastic material includes the following steps:

[0074] S1. Nitrile rubber, polyvinyl chloride, chlorinated polyethylene, epoxidized soybean oil, light calcium carbonate, carbon black, compound flame retardant, flame retardant synergist, solid paraffin wax, stearic acid, polyethylene glycol, and antioxidant 4020 are mixed in an internal mixer. Then, the first part of aluminum hydroxide and the first part of chlorinated paraffin wax are added and the mixture is mixed at 135°C for 2.5 min. Next, the second part of aluminum hydroxide and the second part of chlorinated paraffin wax are added and the mixture is mixed at 155°C for 7 min. After the rubber mixing temperature reaches 168°C, the rubber is discharged onto a two-roll mill. After two-roll milling, the rubber is sliced, cooled, and stacked for 72 h to obtain material No. 1 with a thickness of 8 mm, a width of 600 mm, and a length of 1200 mm. The mass ratio of the first part of aluminum hydroxide to the second part of aluminum hydroxide is 1:1, and the mass ratio of the first part of chlorinated paraffin wax to the second part of chlorinated paraffin wax is 2:1.

[0075] S2. Add sulfur, vulcanization accelerator ZBEC, AC foaming agent and urea ester to the No. 1 material. After mixing evenly by open milling, slice it to obtain No. 2 material with a thickness of 9 mm, a width of 280 mm and a length of 25000 mm.

[0076] S3. The No. 2 material is extruded through an extruder to obtain molding rubber. After the molding rubber is freely foamed, it is cooled by air through a conveyor belt with a cooling distance of 100 m to obtain antimony-free rubber and plastic products.

[0077] The extruder parameters mentioned in step S3 are: feeding section temperature 30℃; plasticizing section temperature 37℃; die head section temperature 40℃.

[0078] The foaming process described in step S3 is carried out in a foaming furnace. The temperature settings for each zone of the foaming furnace are as follows: Zone 1 110℃, Zone 2 125℃, Zone 3 137℃, Zone 4 145℃, Zone 5 160℃, and Zone 6 175℃; the initial transport speed of Zone 1 is 1 m / min.

[0079] The obtained antimony-free rubber and plastic products are sent to a cutting machine for cutting, cut to the required size, and then packaged and stored.

[0080] Example 2

[0081] An antimony-free rubber-plastic material, with the following specific components by weight:

[0082] 10 parts nitrile rubber, 6 parts polyvinyl chloride, 8 parts chlorinated polyethylene, 18 parts chlorinated paraffin, 1 part epoxidized soybean oil, 17 parts aluminum hydroxide, 7.7 parts light calcium carbonate, 12 parts AC foaming agent, 6 parts urea ester, 1.5 parts carbon black, 6.3 parts compound flame retardant, 2.8 parts flame retardant synergist, 1 part solid paraffin, 0.38 parts stearic acid, 0.45 parts polyethylene glycol, 0.3 parts sulfur, 0.07 parts antioxidant 4020, and 1.5 parts vulcanization accelerator ZBEC.

[0083] The mass ratio of the compound flame retardant to the flame retardant synergist is 2.25:1.

[0084] The preparation method of the antimony-free rubber and plastic material includes the following steps:

[0085] S1. Nitrile rubber, polyvinyl chloride, chlorinated polyethylene, epoxidized soybean oil, light calcium carbonate, carbon black, compound flame retardant, flame retardant synergist, solid paraffin wax, stearic acid, polyethylene glycol, and antioxidant 4020 are mixed in an internal mixer. Then, the first part of aluminum hydroxide and the first part of chlorinated paraffin wax are added and the mixture is mixed at 135°C for 2.5 min. Next, the second part of aluminum hydroxide and the second part of chlorinated paraffin wax are added and the mixture is mixed at 155°C for 7 min. After the rubber mixing temperature reaches 168°C, the rubber is discharged onto a two-roll mill. After two-roll milling, the rubber is sliced, cooled, and stacked for 72 h to obtain material No. 1 with a thickness of 8 mm, a width of 600 mm, and a length of 1200 mm. The mass ratio of the first part of aluminum hydroxide to the second part of aluminum hydroxide is 1:1, and the mass ratio of the first part of chlorinated paraffin wax to the second part of chlorinated paraffin wax is 2:1.

[0086] S2. Add sulfur, vulcanization accelerator ZBEC, AC foaming agent and urea ester to the No. 1 material. After mixing evenly by open milling, slice it to obtain No. 2 material with a thickness of 9 mm, a width of 280 mm and a length of 25000 mm.

[0087] S3. The No. 2 material is extruded through an extruder to obtain molding rubber. After the molding rubber is freely foamed, it is cooled by air through a conveyor belt with a cooling distance of 100 m to obtain antimony-free rubber and plastic products.

[0088] The extruder parameters mentioned in step S3 are: feeding section temperature 30℃; plasticizing section temperature 35℃; die head section temperature 40℃;

[0089] The foaming process described in step S3 is carried out in a foaming furnace. The temperature settings for each zone of the foaming furnace are as follows: Zone 1 120℃, Zone 2 128℃, Zone 3 130℃, Zone 4 147℃, Zone 5 160℃, Zone 6 177℃. The initial transport speed of Zone 1 is 1.2 m / min.

[0090] The obtained antimony-free rubber and plastic products are sent to a cutting machine for cutting, cut to the required size, and then packaged and stored.

[0091] Example 3

[0092] An antimony-free rubber-plastic material, with the following specific components by weight:

[0093] The composition includes: 13 parts nitrile rubber, 7 parts polyvinyl chloride, 6 parts chlorinated polyethylene, 16 parts chlorinated paraffin, 0.7 parts epoxidized soybean oil, 20 parts aluminum hydroxide, 8.7 parts light calcium carbonate, 10 parts AC foaming agent, 5 parts urea ester, 1.3 parts carbon black, 5.4 parts compound flame retardant, 3.6 parts flame retardant synergist, 0.7 parts solid paraffin, 0.39 parts stearic acid, 0.35 parts polyethylene glycol, 0.5 parts sulfur, 0.06 parts antioxidant 4020, and 1.3 parts vulcanization accelerator ZBEC.

[0094] The mass ratio of the compound flame retardant to the flame retardant synergist is 1.5:1.

[0095] The preparation method of the antimony-free rubber and plastic material includes the following steps:

[0096] S1. Nitrile rubber, polyvinyl chloride, chlorinated polyethylene, epoxidized soybean oil, light calcium carbonate, carbon black, compound flame retardant, flame retardant synergist, solid paraffin wax, stearic acid, polyethylene glycol, and antioxidant 4020 are mixed in an internal mixer. Then, the first part of aluminum hydroxide and the first part of chlorinated paraffin wax are added and the mixture is mixed at 135°C for 2.5 min. Next, the second part of aluminum hydroxide and the second part of chlorinated paraffin wax are added and the mixture is mixed at 155°C for 7 min. After the rubber mixing temperature reaches 168°C, the rubber is discharged onto a two-roll mill. After two-roll milling, the rubber is sliced, cooled, and stacked for 72 h to obtain material No. 1 with a thickness of 8 mm, a width of 600 mm, and a length of 1200 mm. The mass ratio of the first part of aluminum hydroxide to the second part of aluminum hydroxide is 1:1, and the mass ratio of the first part of chlorinated paraffin wax to the second part of chlorinated paraffin wax is 2:1.

[0097] S2. Add sulfur, vulcanization accelerator ZBEC, AC foaming agent and urea ester to the No. 1 material. After mixing evenly by open milling, slice it to obtain No. 2 material with a thickness of 9 mm, a width of 280 mm and a length of 25000 mm.

[0098] S3. The No. 2 material is extruded through an extruder to obtain molding rubber. After the molding rubber is freely foamed, it is cooled by air through a conveyor belt with a cooling distance of 100 m to obtain antimony-free rubber and plastic products.

[0099] The extruder parameters mentioned in step S3 are: feeding section temperature 35℃; plasticizing section temperature 38℃; die head section temperature 45℃;

[0100] The foaming process described in step S3 is carried out in a foaming furnace. The temperature settings for each zone of the foaming furnace are as follows: Zone 1 115℃, Zone 2 127℃, Zone 3 132℃, Zone 4 147℃, Zone 5 165℃, Zone 6 177℃. The initial transport speed of Zone 1 is 1.1 m / min.

[0101] The obtained antimony-free rubber and plastic products are sent to a cutting machine for cutting, cut to the required size, and then packaged and stored.

[0102] Comparative Example 1

[0103] The difference from Example 3 is that the compound flame retardant is replaced with an equal amount of antimony trioxide.

[0104] Comparative Example 2

[0105] The difference from Example 3 is that the compound flame retardant is replaced with an equal amount of nitrogen-based flame retardant.

[0106] Comparative Example 3

[0107] The difference from Example 3 is that the compound flame retardant is replaced with an equal amount of phosphorus-based flame retardant.

[0108] Comparative Example 4

[0109] The difference from Example 3 is that it does not contain flame retardant synergists.

[0110] Comparative Example 5

[0111] The difference from Example 3 is that it does not contain compound flame retardants.

[0112] Comparative Example 6

[0113] The difference from Example 3 is that the mass ratio of the compound flame retardant to the flame retardant synergist is 4:1.

[0114] Comparative Example 7

[0115] The difference from Example 3 is that the mass ratio of the compound flame retardant to the flame retardant synergist is 1:1.

[0116] Comparative Example 8

[0117] The difference from Example 3 is that it does not contain a flame retardant synergist, and an equal amount of antimony trioxide is used to replace the compound flame retardant.

[0118] The properties of the rubber and plastic materials prepared in the test examples and comparative examples are shown in Table 1.

[0119] Table 1. Test results of rubber and plastic materials.

[0120] Test Standards GB / T6343-2009 GB / T10294-2008 GB / T17794-2021 GB / T2406.1-2008 Example 1 44.5 0.0314 Smooth surface 36.5 Example 2 44.3 0.0312 Smooth surface 36.5 Example 3 43.2 0.0315 Smooth surface 37 Comparative Example 1 45.6 0.0315 Smooth surface 36.5 Comparative Example 2 45.4 0.0314 Surface rough 34 Comparative Example 3 45.8 0.0314 Smooth surface 34.5 Comparative Example 4 46.4 0.0313 Surface rough 33.5 Comparative Example 5 44.2 0.0314 Smooth surface 31 Comparative Example 6 45.5 0.0315 Surface rough 35 Comparative Example 7 44.7 0.0314 Smooth surface 35.5 Comparative Example 8 45.7 0.0316 Smooth surface 36

[0121] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. An antimony-free rubber-plastic material, characterized in that, By weight, it comprises the following components: The composition includes: 7-15 parts nitrile rubber, 6-10 parts polyvinyl chloride, 5-9 parts chlorinated polyethylene, 15-19 parts chlorinated paraffin, 0.7-1.2 parts epoxidized soybean oil, 17-20 parts aluminum hydroxide, 6-10 parts light calcium carbonate, 9-15 parts foaming agent, 4.5-8 parts foaming aid, 1.1-1.7 parts carbon black, 4.5-6.8 parts compound flame retardant, 2.7-4.5 parts flame retardant synergist, 0.5-1 part solid paraffin, 0.15-0.5 parts stearic acid, 0.3-0.6 parts polyethylene glycol, 0.2-0.5 parts sulfur, 0.05-0.08 parts antioxidant, and 0.8-2 parts vulcanization accelerator. The compound flame retardant is composed of ammonium polyphosphate and melamine in a mass ratio of 2:

1. The flame retardant synergist is expandable graphite, pentaerythritol, and zinc borate, and the mass ratio of expandable graphite, pentaerythritol, and zinc borate is 4:25:

10. The mass ratio of the compound flame retardant to the flame retardant synergist is 1.5~2.5:

1.

2. The antimony-free rubber-plastic material according to claim 1, characterized in that, The foaming agent is AC foaming agent, and the foaming aid is one or more of urea ester, adipic acid, and salicylic acid.

3. The antimony-free rubber-plastic material according to claim 1, characterized in that, The antioxidant is antioxidant 4020, and the vulcanization accelerator is one or more of accelerators ZBEC and accelerator TBzTD.

4. The method for preparing antimony-free rubber and plastic materials according to any one of claims 1-3, characterized in that, Includes the following steps: S1. Nitrile rubber, polyvinyl chloride, chlorinated polyethylene, epoxidized soybean oil, light calcium carbonate, carbon black, compound flame retardant, flame retardant synergist, solid paraffin wax, stearic acid, polyethylene glycol, and antioxidant are put into a mixing equipment and mixed. Then, the first part of aluminum hydroxide and the first part of chlorinated paraffin wax are added for a first mixing. Then, the second part of aluminum hydroxide and the second part of chlorinated paraffin wax are added for a second mixing. After the rubber is mixed, the rubber is discharged, sliced ​​after open milling, cooled and allowed to stand to obtain material No.

1. S2. Add sulfur, vulcanization accelerator, foaming agent and foaming aid to material No. 1, mix evenly after open milling, and then slice to obtain material No. 2; S3. The No. 2 material is extruded through an extruder to obtain molding compound. After the molding compound is freely foamed and cooled, antimony-free rubber and plastic products are obtained.

5. The method for preparing antimony-free rubber and plastic materials according to claim 4, characterized in that, In step S1, the mass ratio of the first part of aluminum hydroxide to the second part of aluminum hydroxide is 1:1, and the mass ratio of the first part of chlorinated paraffin to the second part of chlorinated paraffin is 2:1; the temperature of the first internal mixing in step S1 is 135℃, and the time of the first internal mixing is 2~3 min; the temperature of the second internal mixing is 155℃, and the time of the second internal mixing is 7~9 min; the glue discharge temperature in step S1 is 168℃~175℃.

6. The method for preparing antimony-free rubber and plastic materials according to claim 4, characterized in that, The temperature of the feeding section of the extruder described in step S3 is 30℃~38℃, the temperature of the plasticizing section is 35℃~40℃, the temperature of the die head section is 40℃~45℃, the die head pressure is 0.4~0.5MPa, and the rotation speed is 14~18 r / min.

7. The method for preparing antimony-free rubber and plastic materials according to claim 4, characterized in that, The foaming process described in step S3 is carried out in a foaming furnace. The foaming furnace is divided into seven-zone control or six-zone control according to temperature. The temperature settings of each zone of the foaming furnace are as follows: Zone 1 110℃~130℃, Zone 2 115℃~135℃, Zone 3 130℃~140℃, Zone 4 140℃~150℃, Zone 5 150℃~170℃, Zone 6 165℃~180℃. The initial conveying speed of Zone 1 of the foaming furnace is 1.0~1.4 m / min.