Self-extinguishing high-density polymer compound, process for obtaining a self-extinguishing high-density polymer compound, and product

Abstract

The present invention relates to a high-density self-extinguishing polymer compound comprising at least one thermoplastic polymer; at least one metallic or mineral filler of magnetite in an amount of between 68% and 76% by weight, the metallic filler being derived from steelmaking slag; at least one additive; and at least one fiber. The compound exhibits self-extinguishing properties and high resistance to combustion and heavy loads, making it highly suitable for a wide range of applications, including but not limited to, radiation shielding structures, while also offering favorable processability.

Description

Descriptive Report of the Invention Patent for "HIGH DENSITY SELF-EXTINGUISHING POLYMER COMPOUND, PROCESS FOR OBTAINING HIGH DENSITY SELF-EXTINGUISHING POLYMER COMPOUND, AND PRODUCT".

[0001] The present invention relates to a high-density, self-extinguishing polymeric compound that is highly resistant to combustion and capable of withstanding high mineral loads, thus being highly efficient for a range of applications, for example, radiation-blocking structures, and also possessing favorable processability. The present invention also relates to a process for obtaining the aforementioned polymeric compound, and to a product derived from the aforementioned polymeric compound and / or process. Description of the State of the Art

[0002] In view of the rising costs of polyolefins and competition from engineering polymers, the thermoplastic composites industry has shifted its focus from developing high-performance advanced composites to developing low-cost engineering composites.

[0003] Several efforts have been directed towards the development of composites consisting of polymer matrices, such as polyethylene and polypropylene, loaded with inorganic flame retardant particulate fillers and reinforced with glass fibers and hybrid fillers.

[0004] High-density polyethylene (HDPE), in particular, has some properties that hinder expansion in its applications, such as: high coefficient of thermal expansion, low softening temperature, low values ​​of mechanical properties in tension and flexion for applications requiring greater rigidity and strength, low electrical and thermal conductivity for certain applications, among others. Therefore, for a range of applications, it is desirable that HDPE be combined with other elements to obtain certain properties.

[0005] The prior art presents some attempts to use metallic and / or mineral fillers and fibers in conjunction with a high-density polymer for some specific applications. For example, document US9153377 refers to a high-density polymer composite for manufacturing a high-density article by melt-molding, using a combination of high-density polymer, magnetic filler, and fibers.

[0006] In turn, the academic article "Use of iron mine tailing as fillers to polyethylene" by Coura et al. suggests the use of iron mining waste combined with polymer to manufacture flame-retardant structures, although the fillers used here are different from those mentioned in the aforementioned article, since in this case mineral fillers are used. The article by Coura et al. generally indicates the use of polymer and mineral filler in a proportion of 80 / 20 percent by mass, respectively. Another article that considers the possibility of using polymers combined with mineral filler is "Thermal and electrical properties of magnetite-filled polymers" by Widenfeller et al.

[0007] In some cases, as seen in WO 2011 / 095642, the prior art also provides for high-density composites intended for use in radiation-blocking structures. Other examples that can be cited for the use of mineral fillers in polymeric products are document US9153377, which presents high-density compositions for commonly used products such as fishing hooks, or document US9153377, which discloses a process for obtaining the composite that involves melting and subsequent melt molding.

[0008] However, although some of the prior art documents suggest possible fire resistance characteristics of the composite proposed therein (e.g., Coura et al), it was observed that The ranges of composition elements suggested in the prior art are not suitable for more sensitive applications, such as radiation-blocking structures. The applicability and performance of these prior-art composites fall short not only in terms of fire resistance and automatic fire suppression, but also in their ability to maintain their structural integrity during a fire, resulting in flow or melting, and the loss of shielding and handling functions. Furthermore, these composites fall short in the mechanical characteristics required for this type of application, in which the structure must withstand high loads. Objectives of the Invention

[0009] A first objective of the present invention is to provide a self-extinguishing polymeric composite comprising compressive strength characteristics greater than 31 MPa suitable for sensitive applications such as radiation-blocking structures.

[0010] A second objective of the present invention is to provide a self-extinguishing polymer composite comprising a metallic or mineral filler incorporated into the composite in order to provide adequate mechanical and fire resistance characteristics, the mineral or metallic filler being derived from steelmaking slag.

[0011] A third objective of the present invention is to provide a self-extinguishing polymeric composite that, when subjected to fire, maintains its structural integrity without melting or flowing, allowing the maintenance of its shielding and handling functionalities.

[0012] A fourth objective of the present invention is to provide a self-extinguishing polymer composite that has adequate processability despite the high concentrations of mineral filler contained therein.

[0013] A fifth object of the present invention is to provide a process of obtaining the self-extinguishing polymer composite such as the one mentioned above.

[0014] A sixth objective of the present invention is to provide a product derived from the aforementioned self-extinguishing polymer composite and / or the process for obtaining the aforementioned self-extinguishing polymer composite. Brief Description of the Invention

[0015] The present invention relates to a self-extinguishing high-density polymeric compound comprising at least one thermoplastic polymer; at least one metallic or mineral magnetite filler between 68% and 76% by mass derived from steelmaking slag; at least one additive; and at least one fiber.

[0016] In one possible embodiment, the polymer is a polyethylene or a combination of polyethylene and ethylene-propylene-diene.

[0017] In another possible embodiment, the thermoplastic polymer is comprised between 5 to 40% by mass, or preferably between 5 to 15% by mass, or preferably between 7 to 10% by mass.

[0018] In another possible embodiment, the metallic or mineral filler is magnetite comprised of a particle size of 4 to nanometric dimensions or preferably 24 mesh.

[0019] In another possible embodiment, the fiber is comprised between 3 to 15% by mass, or preferably between 5 to 10% by mass.

[0020] In another possible embodiment, the fiber is, or comprises, a glass fiber.

[0021] In another possible embodiment, the additive is between 0.01 and 11% by mass, or preferably between 2 and 3% by mass.

[0022] In another possible embodiment, the additive comprises at least one adhesion promoting agent.

[0023] In another possible embodiment, the compound comprises at least one reinforcing fiber.

[0024] The present invention also contemplates a process for obtaining a self-extinguishing polymeric compound that comprises the steps of mixing, in a mixer, a thermoplastic polymer with at least one additive to obtain a polymer and additive mixture; feeding an extruder with the obtained polymer and additive mixture, at least one metallic or mineral filler of magnetite between 68% and 76% by mass and at least one fiber to obtain a polymer, filler and additive mixture; and extruding the obtained polymer, metallic or mineral filler and additive mixture, the metallic or mineral filler and the fiber to obtain the high-density polymeric compound.

[0025] In one possible embodiment, the process comprises the steps of forming, in a matrix, a blanket from the high-density polymer composite; and cutting the blanket at the exit of the matrix to obtain a blanket section.

[0026] In another possible embodiment, the process comprises the step of keeping the blanket section heated through a greenhouse.

[0027] In another possible embodiment, the process includes the step of shaping the blanket using a press and a mold to obtain a product.

[0028] In another possible embodiment, the process comprises the step of grinding and / or screening the metallic or mineral charge to obtain a metallic or mineral charge with suitable particle size.

[0029] In another possible embodiment, the process comprises the step of grinding the fiber to obtain a fiber of suitable size.

[0030] The present invention also contemplates a product comprising the high-density self-extinguishing polymeric compound as mentioned above in any of its possible embodiments, individually or in combination.

[0031] The present invention also contemplates a product that derives from the process of obtaining a high-density self-extinguishing polymeric compound such as the one mentioned above in any of its possible embodiments, individually or in combination. Brief Description of the Drawings

[0032] The present invention will now be described in more detail based on an example of execution represented in the drawings. The figures show:

[0033] Figure 1 is a first photographic representation of a product derived from the high-density polymeric compound of the present invention in a possible embodiment, arranged in a fire test structure, illustrating the product prior to the test being carried out;

[0034] Figure 2 is a second photographic representation of a product derived from the high-density polymeric compound of the present invention in a possible embodiment, arranged in a fire test structure, illustrating the product prior to testing;

[0035] Figure 3 - is a photographic representation of a product derived from the high-density polymeric compound of the present invention in a possible embodiment, arranged in a fire test structure, illustrating the product after the test has been performed;

[0036] Figure 4 - is a photographic representation of a product derived from the high-density polymeric compound of the present invention in a possible embodiment, arranged in a muffle furnace for fire testing, illustrating the product after the test has been performed;

[0037] Figure 5 - is a graph of torque by percentage of load present in two compositions containing metallic / mineral fillers; and

[0038] Figure 6 - is a schematic representation of the process of obtaining the high-density polymeric compound of the present invention in a preferred embodiment. Detailed Description of Figures

[0039] Initially, it should be noted that the term “preferably” used here aims to characterize particularly efficient embodiments of the present invention among the multiple possible embodiments, and the term should not be considered synonymous with “mandatory” or “imperative”.

[0040] Furthermore, for a better understanding of the present invention, the percentages of the components proposed herein should be understood as a percentage by mass when not expressly indicated otherwise.

[0041] The high-density polymeric compound proposed herein comprises at least one thermoplastic polymer, preferably based on pure ethylene and possibly comonomers. Said polymer may be, for example, a combination of polyethylene (high-density or not) and ethylene-propylene-diene. The thermoplastic polymer is comprised of between 5 and 40% by mass, or preferably between 5 and 15% by mass, or preferably between 7 and 10% by mass. Exemplary embodiments will be presented later in which the polymer is comprised, more preferably, at 7% by mass, or even at 8.8% by mass, or even at 10% by mass, or even at 37% by mass. In some embodiments, a combination of polyethylene and ethylene-propylene-diene in a 2:1 ratio may be used.

[0042] The high-density polymeric compound proposed herein further comprises at least one metallic or mineral filler. Said metallic or mineral filler preferably comprises magnetite, barite, or a combination of magnetite or barite. The metallic or mineral filler is preferably between 30 and 90% by mass, or more preferably between 60 and 85% by mass, or more preferably between 68 and 85% by mass, or most preferably between 80 and 85% by mass. The mineral or metallic filler is preferably derived from Steel mill slag. Exemplary embodiments will be presented later, where the metallic or mineral filler is preferably comprised of 84.6% by mass. Furthermore, test results will be presented later, showing advantageous results with the use of metallic or mineral filler at 50%, 60%, and 68% by mass, with even more expressive results using above 68% by mass, particularly 76% by mass of metallic or mineral filler.

[0043] The high-density polymeric composite proposed herein further comprises at least one additive. Said additive is preferably at least one adhesion promoter, and more preferably, polyethylene functionalized with maleic anide, polyethylene functionalized with acrylic acid, maleic anhydride, silanes, organotitanates, organozirconates, among others. Other additives may be used, in combination or alone, to obtain other desirable characteristics of the composite, such as lubricating additives (e.g., stearin, calcium stearate, zinc stearate, aluminum stearate, among others) and stabilizing additives (e.g., commercial antioxidants). Additives are preferably comprised between 1 and 4% by weight, more preferably between 2 and 3% by weight. Exemplary embodiments will be shown later where additives are comprised at 2.7% by weight.It should be noted that the compound proposed here does not use any flame retardant agents or additives. In some embodiments of the present invention, after combustion, the composite ceases to be a polymer and becomes a metal-ceramic material with high mechanical preservation and high shielding capacity for ionizing radiation.

[0044] The high-density polymer composite proposed herein further comprises at least one fiber. Preferably, the fiber is, or comprises, a glass fiber, with the glass fiber comprising between 3 and 15% by weight, or preferably between 5 and 10% by weight. Exemplary embodiments will be presented later. further where the fiberglass is comprised, more preferably, in 5.6% by mass, 8.8% by mass and 10% by mass.

[0045] The high-density polymer composite proposed herein may also preferably comprise reinforcing fibers such as textile fibers, or textile fiber waste and industrial waste containing fibers. Examples include, but are not limited to, textile and clothing industry waste and industrial waste containing fibers such as cotton, linen, or synthetic fibers such as polyester, polyamide, carbon, aramid, etc. Reinforcing fibers may be combined with glass fiber within the fiber proportions specified above.

[0046] The high-density polymer composite proposed here has demonstrated desirable thermal, density, and mechanical strength characteristics for sensitive applications, such as structures bombarded by radiation and requiring fire protection, such as, but not limited to, oncology treatment bunkers and rooms with X-ray and other radiation equipment. Examples of the implementation of this composite will be demonstrated below. Table 1 - Example 1 Table 2 - Example 2

[0047] Examples 1 and 2 above are possible embodiments of the compound of the present invention in which barite is used as the metallic or mineral filler of the compound. Tests carried out in examples 1 and 2 above indicated that the compounds obtained above comprise a density between 3.2 and 3.4 g / cm 2after pressing, thus confirming the viability of using barite incorporated with the polymer matrix (HDPE) to obtain a high-density compound.

[0048] In general, examples 1 and 2 above can be obtained by initially mixing the powdered components (metallic or mineral filler and flame retardant additives) and low-melting elements (other additives, in this example, stearin, with a melting point of up to 115°C) in a high-speed mixer, preferably with a tangential propeller speed of 35 to 40 m / s, until a temperature of 120°C is reached, with cooling in a slow mixer with a water chamber, to a temperature of 45°. Industrial waste containing natural or synthetic fibers (fabrics), if used, must be reduced in equipment such as a disc shredder, until it is smaller than 30 mm.

[0049] Subsequently, in one possible process, an industrial co-rotating twin-screw extruder, equipped with a main feeder and two side feeders, is used to mix the polymer, the metallic or mineral filler, and the fibers. The polymer is fed into the main feeder. A first side feeder feeds the powdered materials (metallic or mineral filler and additives), and a second side feeder feeds the fibers (glass or other fibers). The composite from the extruder outlet may or may not be granulated with a dry cutting head. The extruder may have the following configurations to obtain a suitable composite: operating temperature between 140 and 200°C; screw rotation at 90 RPM; and torque between 75 and 80 Nm. Optionally, two external dosers, one at 1.8% for polymers and the other at 100% for mineral filler, can be used to dose the polymer and mineral filler. Table 3 - Example 3

[0050] Example 3 above provides a compound whose metallic or mineral filler is a mixture of barite and magnetite, comprising a total metallic or mineral filler of 53.5%. Tests performed on the above composition yielded favorable results, with maximum tensile stress measured between 28 and 30 MPa and a density greater than 3.0 g / cm 2 It was also observed that the maleic anhydride additive proved to be effective in making the metals, fiber and polymer compatible.

[0051] In general, obtaining the compound in example 3 above involves mixing magnetite and barite to obtain the metallic or mineral filler, heating the metallic or mineral filler to 80°C and dispersing the maleic anhydride at this temperature for 30 minutes. Stearin is added and mixed with the metallic or mineral filler after it has cooled. The filler with additives is extruded and granulated in extruder together with the polymer, with the extruder comprising a configuration similar to that of examples 1, 2 and 3, but with a setup of two dosers at 5.2% and 50%, respectively. Subsequently, the obtained granulate is mixed with the glass fiber or other fibers, and the resulting mixture is processed in a new conical twin-screw extruder. Optionally, after a first extrusion in the conical twin-screw extruder, a second extrusion can be performed in an extruder (e.g., Haake) for greater dispersion of the components. Table 4 - Example 4 Table 5 - Example 5 Table 6 - Example 6 Table 7 - Example 7 Table 8 - Example 8 Table 9 - Example 9

[0052] Examples 4 to 9 presented above generally represent high-density polymer compositions. comprising only magnetite as a metallic or mineral filler. In this sense, tests have demonstrated that magnetite has an excellent affinity with polyethylene in the composite production process, with easy dispersion, resulting in a compound with excellent load absorption capacity, and allowing the use of high proportions of metallic or mineral filler in the composite while maintaining the desired mechanical strength characteristics of the final product. Magnetite also has a lower cost than barite in general, making it a cheaper alternative to metallic or mineral filler.Therefore, the use of magnetite as a single metallic or mineral filler advantageously allows for the production of a low-cost composite with mechanical characteristics and density suitable for application in structures for radiation protection, for example, but not limited to, bunkers for oncological treatment and rooms with X-ray and other radiation equipment.

[0053] Additionally, and surprisingly, the combination of the high metallic or mineral charge of magnetite with polyethylene (or polyethylene and ethylene-propylene-diene), fiberglass, and an adhesion-promoting additive results in a high-density polymeric composition that exhibits non-melting or non-flowing behavior when subjected to high temperatures (up to approximately 500°C), observed, for example, in fire situations. In other words, the compositions in Examples 4 to 9 above are capable of maintaining their structural integrity under fire conditions. This is understood to be due to the fact that the composition comprising the above elements undergoes an effect similar to that of sintering when subjected to partial pyrolysis, as a result of oxidative heating, as would be the case in a building fire.The result of this “sintering”-like behavior is that, after subjecting the compound to fire-like conditions, a structure is formed. This compound results in a hard material that maintains its integrity with good compressive strength. This property is highly desirable in applications involving structures exposed to radiation, since, in the event of a building fire, the radiation barrier remains intact during personnel evacuation, as well as during rescue operations or hazardous waste removal.

[0054] Figures 1 to 4 show photographs of a set of blocks 10 manufactured using the composite of Example 8. Figures 1 and 2 show the set of blocks 10 semi-enclosed in a structure for conducting a fire test. Figure 3 shows the set of blocks 10 after the test, demonstrating the maintenance of the structural integrity of the blocks 10 derived from the composite of the present invention under these conditions. The fire tests were repeated on the blocks 10 in a muffle furnace and showed the same behavior, as can be seen in Figure 4.

[0055] The tables below illustrate the results of tensile strength tests (performed in accordance with JIS K71 13:1981) and impact tests (performed in accordance with J IS 7062) carried out on test specimens derived from the compositions of examples 4 to 9 above, proving that they comprise desirable mechanical strength for applications in structures for radiation protection: Table 10 - Tensile strength test results Table 11 - Impact resistance test results

[0056] To confirm the positive effects of using magnetite as a metallic / mineral filler in the compositions proposed here, torque tests (in accordance with ASTM D2538-18) were performed on specimens from Example 4, as well as on specimens similar to Example 4 with the magnetite replaced by talc, another commonly used mineral filler found on the market. The test results can be seen in Figure 5.

[0057] Figure 5 shows a notable reduction in torque experienced by the composition containing magnetite compared to the same composition using talc, especially at high dosages. The torque reduction is particularly significant at higher filler concentrations, for example, between 68% and 76%. It is also important to note a particularly advantageous and unexpected feature of the composition proposed here: the use of magnetite as a metallic or mineral filler allows the incorporation of high concentrations of metallic or mineral filler into the compound, which is not observed with talc or other metallic / mineral fillers. For example, attempts to incorporate talc mineral fillers above 68% in the composition of example 8 as a replacement for magnetite were unsuccessful. This means that the use of magnetite in the composition proposed here allows for higher levels of metallic or mineral filler within the composition, resulting in benefits in mechanical strength, cost, and thermal resistance, self-extinguishing characteristics and ease of processing, as explained above.

[0058] In general, the metallic or mineral fillers used in examples 1 to 9 above may comprise a specific particle size suitable for blender and extruder processing to ensure adequate processability and mechanical strength characteristics of the compound. In the case of barite, the particle size may range from 100 to 300 mesh, preferably from 150 to 250 mesh, more preferably from 100 to 200 mesh, and more preferably larger grain sizes within the above ranges. In the case of magnetite, the particle size may range from 5 to 200 mesh, preferably from 15 to 150 mesh, more preferably from 24 to 115 mesh, and most preferably larger grain sizes within the above ranges.Advantageously, the use of magnetite as a metallic / mineral filler allows the use of larger particle sizes compared to barite, with no significant differences in process or mechanical properties having been noted when using grain sizes smaller than 24 mesh.

[0059] Additionally, it is important to emphasize the sustainability of the compound proposed here, both from an economic and ecological perspective. This is because the use of metallic or mineral filler derived from steelmaking not only allows for greater production viability of the compound by reducing costs, but also provides a suitable solution for reusing the industrial waste in question.

[0060] In accordance with the high-density polymeric compound presented above in its different embodiments, the present invention also contemplates a process for obtaining a high-density polymeric compound such as the one mentioned above, comprising the steps of: mixing 100, in a mixer, a high-density polymer thermoplastic density 20 with at least one additive 21 to obtain a mixture of polymer and additive 22; feeding 110 an extruder with the mixture of polymer and additive 22 obtained, at least one metallic or mineral filler 30 and at least one fiber 31 to obtain a mixture of polymer, filler and additive 32; and extruding 120 the mixture of polymer, filler and additive 32 obtained, the metallic or mineral filler 30 and the fiber 31 to obtain the high-density polymer compound 40. A preferred embodiment of the above process can be seen in figure 6.

[0061] In a preferred embodiment of the above process, as seen in Figure 6, a mixer 100 is used to mix a thermoplastic polymer 20 with at least one additive 21. As already clarified, the thermoplastic polymer can be a polyethylene (high density or not) or an ethylene-propylene-diene, or a combination of these two. The additives can be any additives already mentioned applicable to the high density compound proposed here, for example, an adhesion promoting agent or others.

[0062] The polymer-additive mixture 22 obtained from the mixer is then fed 110 into an extruder with at least one metallic or mineral filler 30 and at least one fiber 31 to obtain a polymer, filler, and additive mixture 32. As already explained, the metallic or mineral filler may be barite, magnetite, or a mixture of barite and magnetite. The fiber, in turn, is preferably a glass fiber, a reinforcing fiber, or a combination of both types of fiber.

[0063] Preferably, the polymer and additive mixture 22 is fed into an extruder hopper. A side feeder feeds the metallic or mineral filler 30. In some applications, it may be necessary to add the metallic or mineral filler through two side feeders if the volume of this filler is substantially high compared to the other components.

[0064] Still preferably, at another inlet of the extruder, the fiber 31 (for example, fiberglass) is fed directly into strands (“roving”) that enter and are cut by the screws of the extruder.

[0065] Extrusion 120 of the mixture 32 of the above elements (metallic or mineral filler, polymer and additive mixture, and fiber) by the extruder results in a high-density polymeric compound 40 such as the above.

[0066] To obtain a product derived from the high-density polymeric compound proposed herein, the aforementioned process may further comprise the steps of forming 130, in a die, a web 50 of the high-density polymeric composite; and cutting the web 140 at the die exit into a geometry suitable for the desired product, obtaining a web section 51. Preferably, the process further comprises the step of maintaining the heated web section 150 through an oven. More preferably, the web section 51 is transported by a metal belt, with heating (oven) along the belt, to maintain the web at the appropriate temperature for pressing.

[0067] Furthermore, the process may further comprise the step of shaping the blanket using a press and a mold. The blanket is preferably placed in the mold, and the press allows it to be formed onto the mold to obtain the desired final product. In one possible example, a pressure between 40 and 80 bar for 1 to 3 minutes may be used to press the blanket onto the mold.

[0068] Preferably, the mold may also comprise the following characteristics or elements: ejection system to demold the part; heating sized to be able to reach the ideal forming temperature quickly, this temperature being preferably between 120°C and 240°C, since the compression cycle requires cooling of the part in order to be able to demold; refrigeration circuit, ideally properly used to cool the part to the demolding temperature, preferably 120°C to 160°C, but which does not cool the mold assembly too much, increasing the production cycle; post-molding cooling belt, with an adequate cooling system that does not produce deformation in the parts.

[0069] Furthermore, the process proposed herein may further comprise a grinding and / or screening step 100A of the metallic or mineral fillers to obtain the appropriate particle size, as indicated above. The process proposed herein may further comprise a grinding step 100B of the fibers to obtain an appropriate fiber size for extrusion.

[0070] Having described a preferred embodiment, it should be understood that the scope of the present invention encompasses other possible variations, being limited only by the content of the appended claims, including possible equivalents.

Claims

CLAIMS 1. Self-extinguishing high-density polymeric compound characterized by the fact that it comprises: - at least one thermoplastic polymer based on ethylene and co-monomers; - at least one mineral or metallic filler of magnetite between 68% and 76% by mass, the mineral or metallic filler being derived from steel slag; - at least one additive; and - at least one fiber.

2. High density polymeric compound, according to claim 1, characterized by the fact that the thermoplastic polymer is a polyethylene or a combination between high density polyethylene and ethylene-propylene-diene.

3. High density polymeric compound, according to claim 1, characterized by the fact that the thermoplastic polymer is comprised between 5 to 40% by mass, or preferably between 5 to 15% by mass, or preferably between 7 to 10% by mass.

4. High density polymeric compound according to any one of the preceding claims, characterized in that the metallic or mineral filler comprises magnetite, barite or a combination of magnetite or barite.

5. High density polymeric compound according to any one of the preceding claims, characterized in that the metallic or mineral filler is between 30 and 90% by weight, or more preferably between 60 and 85% by weight, or more preferably between 68 and 85% by weight, or more preferably between 80 and 85% by weight.

6. High density self-extinguishing polymeric compound according to any one of the preceding claims, characterized because the metallic or mineral charge is magnetite comprised of a granulometry of 4 mesh to nanometric dimensions, or preferably 24 mesh.

7. High-density self-extinguishing polymeric compound according to any one of the preceding claims, characterized in that the fiber is comprised between 3 to 15% by mass, or preferably between 5 to 10% by mass.

8. High-density self-extinguishing polymeric compound according to any one of the preceding claims, characterized in that the fiber is, or comprises, a glass fiber.

9. High-density self-extinguishing polymeric compound according to any one of the preceding claims, characterized in that the additive is comprised between 0.01 to 11% by mass, or preferably between 2 to 3% by mass.

10. High-density self-extinguishing polymeric compound according to any one of the preceding claims, characterized in that the additive comprises at least one adhesion promoting agent.

11. High-density self-extinguishing polymeric compound according to any one of the preceding claims, characterized in that it comprises at least one reinforcing fiber.

12. Process for obtaining a high-density self-extinguishing polymeric compound, characterized by the fact that it comprises the steps of: - mixing (100), in a mixer, a thermoplastic polymer (20) with at least one additive (21) to obtain a mixture of polymer and additive (22); - feeding (110) an extruder with the polymer and additive mixture (22) obtained, at least one metallic or mineral charge (30) of magnetite between 68% and 76% by mass and at least one fiber (31) for obtaining a mixture of polymer, filler and additive (32), the metallic or mineral filler being derived from steel slag; and - extrude (120) the mixture of polymer, filler and additive (32) obtained, the metallic or mineral filler (30) and the fiber (31) to obtain the high-density polymer compound (40).

13. Process for obtaining a high-density self-extinguishing polymeric compound, according to claim 12, characterized by the fact that it comprises the steps of: - forming (130), in a matrix, a blanket (50) from the high-density polymer composite (40); and - cut (140) the blanket (50) at the matrix outlet to obtain a blanket section (51).

14. Process for obtaining a high-density self-extinguishing polymeric compound, according to claim 12, characterized by the fact that it comprises the step of keeping the blanket heated (150) through a stove.

15. Process for obtaining a high-density self-extinguishing polymeric compound, according to claim 12, characterized by the fact that it comprises the step of molding (160) the blanket using a press and a mold to obtain a product (60).

16. Process for obtaining a high-density self-extinguishing polymeric compound, according to any one of the previous claims, characterized by the fact that it comprises the step of grinding and / or sieving (100A) the metallic or mineral charge to obtain a metallic or mineral charge with suitable granulometry.

17. Process for obtaining a high-density self-extinguishing polymeric compound, according to any one of the preceding claims, characterized in that it comprises grinding stage (100B) the fiber to obtain a fiber of suitable size.

18. Product characterized by the fact that it comprises the high-density polymeric compound as defined in any one of claims 1 to 17.

19. Product characterized by the fact that it is obtained by a process as defined in any one of claims 1 to 17.

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