PROCESS FOR EXTRACTION, QUANTIFICATION AND RECOVERY OF POLYPROPYLENE ADDITIVES WITH BIODEGRADABLE NATURAL SOLVENTS

Abstract

PROCESS OF EXTRACTION, QUANTIFICATION AND RECOVERY OF POLYPROPYLENE ADDITIVES WITH BIODEGRADABLE NATURAL SOLVENTS AND USE OF POLYPROPYLENE RESULTING FROM MULTIPLE EXTRACTIONS.The present invention is directed to a process for extracting, quantifying and recovering polypropylene additives, characterized in that it comprises the steps of washing the plastic material (A), grinding the material (A) to a particle size between 10 and 500 microns, extraction in which the material (A) is transferred to a column (1) and then successively said material passes to column (2), column (3) and column (4) respectively for successive extractions with solvents (I), (II), (III) and (IV), extraction in packed columns, in which the solvent with the additives obtained from each extraction of columns (1), (2), (3) and (4) passes through a packed column (1?), (2?), (3?) and (4?), respectively, crystallization of the additives obtained after each extraction step in the packed columns (1?), (2?), (3?) and (4?), respectively; and quantification of the additives obtained and in which the waste material without the additives is subjected to pyrolysis.

Description

PROCESS FOR EXTRACTION, QUANTIFICATION AND RECOVERY OF POLYPROPYLENE ADDITIVES WITH BIODEGRADABLE NATURAL SOLVENTS TECHNICAL FIELD

[001] The present invention is situated in the field of polymer industry and research, primarily with the recovery of polypropylene additives through biodegradable natural solvents. The invention also focuses on the application of the circular economy since the polypropylene resulting from the extraction can be reused or pyrolyzed with lower energy consumption. SUMMARY

[002] The present invention relates to a process for the extraction, quantification and recovery of polypropylene additives using biodegradable natural solvents, based on cymene, myrcene (beta-myrcene), thymol, menthol, menthone, terpineol, limonene, pinene, borneol (2-camphanol), piperitone, citral, carvone, eugenol, citronellal, apiol, alpha bisabolol, chamazulene, tea tree, jasmine, German apple or matricaria, laurel, niaouli, everlasting flower, linalool, eucalyptol (1,8-cineole), melisa, caryophyllene, beta-caryophyllene, caryophyllene oxide, carene, phellandrene, pyrethrin, camphor (2-camphanone), farnesol, vitamin A, beta-carotene, and other derivatives of monoterpenes, sesquiterpenes, diterpenes, phytosterols, Phytostanols, where the process comprises open recycling, closed recycling, Soxhlet extraction, ultrasound, supercritical fluid extraction, and microwave extraction steps, with solid-phase extraction and purification steps using columns packed with materials that allow for said extraction, quantification, and recovery. Petition 870260052979, dated 01 / 06 / 2026, page 11 / 41 2 / 19 BRIEF DESCRIPTION OF THE FIGURES

[003] Figure 1 shows a diagram of the process according to the invention. BACKGROUND OF THE INVENTION

[004] Polymeric plastic materials generally contain additives or chemical substances necessary to make said materials useful elements with desired physical-chemical characteristics depending on the final application for which said material is intended. Additionally, additives allow for stabilization and compatibility of the mixtures during the plastic processing stages.

[005] Depending on the intended end application of the polymeric plastic materials, additives can be flame retardants, stabilizers (antioxidants), foaming agents, plasticizers, ultraviolet (UV) light absorbers, antistatic agents, and antibacterial agents, among many others. In the case of flame retardant additives, as their name indicates, they are applied to reduce the flammability of the material and delay the spread of fire on its surface. In the case of stabilizers (antioxidants), these are substances that provide stability both during the production or transformation of the material and during its use in a specific application, in order to prevent undesirable characteristics such as discoloration, yellowing, loss of mechanical properties and rigidity, among others.

[006] For their part, foaming agents can be used to provide an insulating foam-like structure in the final product and provide the material with characteristics such as low density and volume between Petition 870260052979, dated 01 / 06 / 2026, page 12 / 41 3 / 19 others. Plasticizers help polymers improve their processability and flexibility by modifying their properties in the glass transition state. Ultraviolet light absorbers provide greater stability and durability to polymers that will be used in weathering, helping to extend their lifespan. Antistatic and antibacterial agents, as their names indicate, help prevent the formation of static charges in polymers and inhibit bacteria in polymers, respectively.

[007] Given the importance of the impact of additives as agents that stabilize the structure of polymeric materials, making them virtually impossible to degrade in the short term, and the importance of recycling and reusing the constituent elements of said materials without causing greater damage to the environment, the aim was to recover the additives used in said polymeric materials.

[008] In this sense, US patent 2003 / 0191202 teaches a method for separating polymers and their additives from a material containing polymers, wherein the method is based on the principle of precipitating the polymer object and then separating it from its additives present in the solution. The separation of the additives from the solution is carried out in an additional step. The method comprises the steps of grinding and pre-cleaning the material, then selective extraction and further cleaning. After these steps, a solvent is added, precipitation is carried out, drying occurs, a second solvent is added (which may be different from the first), and the additives present in the liquid phase are separated, mainly by distillation, where the solvents are tetrahydrofuran (THF), aliphatic ketones, Petition 870260052979, dated 01 / 06 / 2026, page 13 / 41 4 / 19 alcohols and aromatic organic solvents.

[009] Also known is the article “A rapid ultrasonic extraction technique to identify and quantify additives in poly(ethylene)” by Nadejzda and colleagues, which teaches a procedure for the analysis of aromatic antioxidants and UV stabilizers in polyethylene. The separation of the additives is carried out by ultrasonic extraction with chloroform at 60°C for the separation of chimassorb 944 from a commercially available low-density polyethylene film and the separation of irganox 1010 and irgafos 168 from medium-density polyethylene films. Their quantification is carried out by UV spectroscopy and HPLC with acetonitrile as the mobile phase and at a wavelength of 280 nm.This investigation reports the effects of temperature, time, and additive structure as key factors affecting extraction efficiency and reports that recovery was achieved after 15 minutes, 45 minutes, and 60 minutes at 60°C for Irgafos 168, Irganox 1010, and Chimassorb 944, respectively.

[0010] Another document related to the polypropylene recycling process is patent document CN106279753, which reports a cross-linked polymer recovery process comprising the following steps: step 1) pre-treatment of waste cross-linked polypropylene: performing surface spray cleaning and ultraviolet sterilization on the waste cross-linked polypropylene; step 2) depolymerization and recycling of waste cross-linked polypropylene: breaking down the waste cross-linked polypropylene treated in step 1), aggregation to an extruder and depolymerization of a chain. Petition 870260052979, dated 01 / 06 / 2026, page 14 / 41 5 / 19 molecular weight cross-linked polypropylene under high temperature and alternating shear action to achieve recycling. The recycling process of cross-linked polypropylene has the benefits of being more environmentally friendly and more efficient, such that the depolymerized polypropylene has fluidity at high temperatures. The recycling process can be applied directly to product production and solves the problems of contamination and low efficiency of traditional treatment methods. In this case, the patent teaches the recycling of all constituent elements of the plastic material without differentiating or extracting them.

[0011] As can be seen, although the previous technique teaches processes for the recovery and recycling of polymeric materials such as polypropylene and other polymers and an effort to separate the additives that compose it, it is also true that the processes / methods do not help to minimize environmental problems, on the contrary, they promote environmental pollution by employing organic solvents resistant to biodegradation in their steps.

[0012] Most processes that transform plastic waste or byproducts present in the environment to obtain gas, propane, propylene, naphtha, ammonia, hydrogen, kerosene, etc., take polypropylene (PP), grind it, and introduce it into a pyrolysis furnace. When PP is additivated and / or thermally stabilized, a greater amount of energy and oxygen is required to transform all this material into the byproducts and products of interest. Furthermore, the pyrolysis of this additivated waste will generate greenhouse gases (SOx, NOx), and materials toxic to health, such as Petition 870260052979, dated 01 / 06 / 2026, page 15 / 41 6 / 19 dioxins and furans, among others. The toxic material is eliminated with the present invention, since the material will already be free of additives, thus the pyrolysis of said material, already treated in the extraction and recovery of additives process of the present invention, is much more efficient and cleaner compared to traditional methods, since energy consumption is lower given that the material is no longer stabilized and the generation of greenhouse gases is also reduced. This is a technical advantage of the present invention, given that most companies only pyrolyze in the open air, emitting a large quantity of gases that are harmful to the environment.

[0013] In this sense, the present invention makes a considerable contribution to solving the difficult extraction, quantification and recovery of additives that are part of unused or used polymeric materials, which is achieved through a process of extraction, quantification and recovery of polypropylene additives with biodegradable natural solvents such as limonene, pinene and other compounds or derivatives of terpenes, hemiterpenes, monoterpenes, sesquiterpenes, diterpenes, triterpenes, polyterpenes and meroterpenes and mixtures thereof, wherein the extraction process comprises open recycling, closed recycling, soxhlet, ultrasound, supercritical fluid and microwave steps with solid phase extraction and purification steps using columns packed with materials that allow said extraction, quantification and recovery.

[0014] Recovering these additives in recycled material with a shorter lifespan prevents their migration into bodies of water or other environments. Petition 870260052979, dated 01 / 06 / 2026, p. 16 / 41 7 / 19 environmental. Once these additives are recovered, the resin must have a high percentage of purity, that is, it is pure.

[0015] The high-purity resin obtained after successive extractions can be reused or undergo a pyrolysis process. Pyrolysis of this material will have: lower energy consumption (since it requires oxidizing the chains without thermal stabilizers), a smaller quantity of combustion gases (NOx, SOx, DIOXINS, FURANS) and, therefore, the pyrolysis process is cleaner. DETAILED DESCRIPTION OF THE INVENTION

[0016] The present invention relates to a process, which can be carried out on a laboratory scale and easily implemented on an industrial scale, in which the process has the following steps: Step 1: Washing; Step 2: Grinding; Step 3: Extraction in columns (1), (2), (3) and (4); Step 4: Extraction in packed columns (1'), (2'), (3') and (4'), respectively; Step 5: crystallization of the additives obtained in each extraction step 4 in the packed columns (1'), (2'), (3') and (4') respectively, and Step 6: Quantification and recovery of obtained additives. In this sense, the present invention covers a process for the extraction, quantification, and recovery of polypropylene additives and the utilization of the latter, wherein the process comprises the following steps: 1. Washing of the plastic material (A); 2. Grinding, in a crushing machine or mill, of Petition 870260052979, dated 01 / 06 / 2026, p. 17 / 41 8 / 19 material (A) up to particle size between 10 and 500 microns; 3. Extraction where material (A) from step 2 is transferred to a column (1) and then, successively, material (A) passes to column (2), column (3) and column (4) respectively, being identified in each case as A'; A” and A' for successive solvent extractions (I), (II), (III) and (IV); 4. A subsequent extraction step in packed columns (1'), (2'), (3') and (4'), in which the solvent with the additives obtained from each extraction of columns (1), (2), (3) and (4) passes through a packed column (1'), (2'), (3') and (4') respectively; 5. A subsequent crystallization step of the additives obtained after each extraction step in the packed columns (1'), (2'), (3') and (4') respectively and with the consequent recovery of the solvent; and 6. Quantification of the additives obtained and final disposal of the residual material A''' after the last extraction in column (4) by means of pyrolysis; and in which the residual material without additives is subjected to a subsequent pyrolysis process.

[0017] As shown in Figure 1, the plastic waste material (A), preferably PP, PE, PVS and PS, is subjected to step 1) washing with water at a temperature of 35°C. In step 2) grinding, the plastic waste material is subjected to particle size reduction until particles with dimensions between 50 and 100 microns are obtained. Subsequently, in step 3) extraction, this material is subjected to four extraction sub-steps, where the plastic waste material (A) remaining in the first Petition 870260052979, dated 01 / 06 / 2026, page 18 / 41 9 / 19 column is subjected to a subsequent extraction in the next column until it reaches the substep in column (4).

[0018] In Figure 1, each plastic waste material entering the subsequent column after column (1) is identified with the letter A'; A' and A'. Columns (1), (2), (3) and (4) can be of any dimension and material, depending on the amount of material to be recycled, for example, the columns can be made of glass, stainless steel, aluminum or other resistant material for columns or towers used in industrial chemistry, where the columns can be conventional cylindrical devices whose height is greater than their diameter. For example, but not limited to, for the case of the extraction process at the laboratory level, the columns can be borosilicate glass columns one meter high and a nominal diameter of 12.7 cm (5 inches) and inside they can have one or more stainless steel trays to support the plastic waste (A), (A'); (A) and (A'), depending on the case and column (1) to (4) where the process material is found.

[0019] The extraction product, that is, the solvent or mixture of solvents with the dissolved components resulting from each of the columns (1), (2), (3) and (4) passes respectively through a packed column (1'), (2'), (3') and (4') where each of these packed columns comprises a different packing constituted as follows:

[0020] The packed column (1') contains from 85% to 95% of a modified styrene-divinylbenzene polymer (Strata X33), preferably (90% of a modified styrene-divinylbenzene polymer (Strata X-33), from 7.5% to 2.5% of Petition 870260052979, dated 01 / 06 / 2026, page 19 / 41 10 / 19 activated carbon, preferably 5% activated carbon; and 2.5% to 7.5% silanized glass wool), preferably 5%.

[0021] The packed column (2') contains from 80% to 90% of a modified styrene-divinylbenzene polymer (Strata X33), preferably 85% of a modified styrene-divinylbenzene polymer (Strata X-33), from 7.5% to 15% of activated carbon, preferably 10% of activated carbon; and from 2.5% to 5% of silanized glass wool, preferably 5% of silanized glass wool.

[0022] The packed column (3') contains from 70% to 90% of a modified styrene-divinylbenzene polymer (Strata X33), preferably 80% of a modified styrene-divinylbenzene polymer (Strata X-33), from 5% to 15% of activated carbon, preferably 10% of activated carbon, and from 5% to 15% of silanized glass wool, preferably 10% of silanized glass wool.

[0023] The packed column (4') contains from 70% to 90% of a modified styrene-divinylbenzene polymer (Strata X33), preferably 80% of a modified styrene-divinylbenzene polymer (Strata X-33), from 5% to 15% of activated carbon, preferably 10% of activated carbon; and from 5% to 15% of silanized glass wool, preferably 10% of silanized glass wool.

[0024] The element or component of a modified styrene-divinylbenzene polymer (Strata X-33) refers to a reverse-phase functionalized polymeric sorbent that provides strong retention of neutral, acidic, or basic compounds under high and aggressive organic washing conditions, where this sorbent performs the retention Petition 870260052979, dated 01 / 06 / 2026, page 20 / 41 11 / 19 by means of retention mechanisms, which are pi-pi bonds, hydrogen bonds, i.e., dipole-dipole interactions and hydrophobic interactions. These packings allow the additives of interest to be separated and then subjected, each of them, to a crystallization substep to obtain the crystalline additives, quantify them and recover the solvent used in each of the columns (1), (2), (3) and (4).

[0025] According to step 1 of the extraction, quantification and recovery process of additives of the invention, the mixture of plastic waste (PP, PE and PVC), which may be unused or used, referred to as (A), passes through a washing tank with water at a temperature between 20 and 50°C, more preferably between 30 and 40°C and preferably at 35°C. This tank has a mechanical agitation system in order to eliminate external impurities from the material.

[0026] According to step 2 of the extraction, quantification and recovery process of additives of the invention, the material passes through a crushing machine or mill, which allows reducing the particle size of the material obtained from washing step 1, to achieve a particle size between 10 and 500 microns, more preferably between 20 and 200 microns, and even more preferably between 50 and 100 microns.

[0027] Once the material reaches the desired particle size, column extraction step 3 begins, in which each of the additives of interest is extracted. For this purpose, there are four columns (1), (2), (3) and (4) filled with different solvents, each column has a controlled heating system, ultrasound or microwave system and / or supercritical fluid. In this column extraction step 3 (1), (2), (3) and (4) according to Petition 870260052979, dated 01 / 06 / 2026, page 21 / 41 12 / 19 with the present invention, the following procedures are performed:

[0028] The recycled polymeric material (A) is transferred to column (1) and solid-liquid extraction is carried out for 2 to 3 hours using l-methyl-4-(1-methylethenyl)-cyclohexene (limonene) as solvent (I). Column (1) is heated to a temperature between 40 and 70°C, more preferably to 60°C and energy is applied by ultrasound or microwave radiation. After that, the solvent enriched with the additives extracted in column (1) is subjected to the packed column extraction step 4, specifically to a separation in the packed column (1”), which contains from 85% to 95% of a modified styrene-divinylbenzene polymer (Strata X-33), preferably 90% of a modified styrene-divinylbenzene polymer (Strata X-33), from 7.5% to 2.5% of activated carbon, preferably 5% of activated carbon; and from 7.5% to 2.5% of silanized glass wool), preferably 5%.After the above procedure, the solvent is recovered and the additives cis-13docosenamide (Erucamide), cis-9-octadecenamide (oleamide) and glycerol palmitate monostearate (GMS) proceed to step 5 of crystallization, which is carried out according to the basic concepts of crystallization, and subsequently, proceed to the final step 6 of quantification of the additives obtained.

[0029] After treatment in column 1 with solvent (I), the recycled polymeric material now called (A') passes to column (2), where solid-liquid extraction is carried out for 2 to 3 hours, using as solvent (II) a mixture of cyclohexane: l-methyl-4-(1-methylethenyl) Petition 870260052979, dated 01 / 06 / 2026, page 22 / 41 13 / 19 cyclohexene (limonene) in proportions between 20:80 and 80:20.

[0030] Column (2) is heated to a temperature between 40 and 70°C, preferably 60°C, and energy is applied by ultrasound or microwave radiation. After that, the solvent enriched with the additives extracted in column (2) is subjected to separation in the packed column (2'), which contains 80% to 90% of a modified styrene-divinylbenzene polymer (Strata X-33), preferably 85% of a modified styrene-divinylbenzene polymer (Strata X-33), 7.5% to 15% of activated carbon, preferably 10% of activated carbon; and 2.5% to 5% of silanized glass wool, preferably 5% silanized glass wool. After the previous procedure, the solvent is recovered and the octadecyl-3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate additive proceeds to step 5 of crystallization, which is carried out according to the basic concepts of crystallization, before moving on to the final step 6 of quantification of the additives obtained.

[0031] After treatment in column (2), the recycled polymeric material now called (A) passes through column (3), where solid-liquid extraction is carried out for 2 to 3 hours, using as solvent (III) a mixture of toluene:cyclohexane in proportions ranging from 20:80 to 80:20. Column (3) is heated to a temperature between 40 and 70°C, preferably 60°C, and energy is applied by ultrasound or microwave radiation. After that, the solvent enriched with the additives extracted in column (3) is subjected to separation in the packed column (3), which contains from 70% to 90% of a styrene polymer. Petition 870260052979, dated 01 / 06 / 2026, page 23 / 41 14 / 19 modified divinylbenzene (Strata X-33), preferably 80 of a modified styrene-divinylbenzene polymer (Strata X-33), 5% to 15% activated carbon, preferably 10% activated carbon, and 5% to 15% silanized glass wool, preferably 10% silanized glass wool. After the previous procedure, the solvent and the separated additives are recovered: octadecyl-3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate (Irganox 1076), pentaerythritol tetracis(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate) (Irganox 1010), 1,3,5-trimethyl-2,4,6-tris(3,5-di-tert-butyl-4-hydroxybenzyl)benzene (Etanox 330), tris(2,4-ditert-butylphenyl)phosphite (irgafox 168), bis(2,4-dicumylphenyl)pentaerythritol diphosphite (doverohos), 1,3,5tris(4-tert-butyl-3-hydroxy-2,6-dimethylbenzyl)-1,3,5-triazin-2,4,6-(1H,3H,5H)-trione (cyanox 1790); proceed to step 5 of crystallization, which is carried out according to the basic concepts of crystallization, to subsequently reach the final step 6 of quantification of the additives obtained.

[0032] After treatment in column (3), the recycled polymeric material now called (A') passes through column (4), in which solid-liquid extraction is carried out for 2 to 3 hours, using as solvent (IV) a mixture of toluene: l-methyl-4-(1-methylethenyl)-cyclohexene (limonene) in proportions ranging from 20:80 to 80:20. Column (4) is heated to a temperature between 40 and 70°C, preferably 60°C, and energy is applied by ultrasound or microwave radiation.After that, the solvent enriched with the additives extracted in column (4) is subjected to a separation in the packed column (4), which contains from 70% to 90% of a modified styrene-divinylbenzene polymer (Strata X-33). Petition 870260052979, dated 01 / 06 / 2026, page 24 / 41 15 / 19 preferably 80% of a modified styrene-divinylbenzene polymer (Strata X-33), 5% to 15% activated carbon, preferably 10% activated carbon; and 5% to 15% silanized glass wool, preferably 10% silanized glass wool. After the previous procedure, the solvent and the separated additives are recovered: Pentaerythritol tetracis(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate) (Irganox 1010), 1,3,5-trimethyl-2,4,6-tris(3,5-di-tert-butyl-4-hydroxybenzyl)benzene (Etanox 330), Tris(2,4-ditert-butylphenyl)phosphite (Irganox 168), bis(2,4-dicumylphenyl)pentaerythritol diphosphite (Doverohos), 1,3,5-tris(4-tert-butyl-3-hydroxy-2,6-dimethylbenzyl)-1,3,5-triazin-2,4,6-(1H,3H,5H)-trione (Cyanox 1790) proceed to step 5 of crystallization, which is carried out according to the basic concepts of crystallization, in order to subsequently reach the final stage 6 of quantifying the additives obtained.

[0033] In one embodiment of the invention, the columns (1'), (2'), (3') and (4') that participate in step 4 of the process, according to the present invention, are filled in the order indicated, that is, at the bottom of the column is the component with the highest proportion, then the activated carbon and at the top, the silanized glass wool. In another embodiment of the invention, the order of the components within the column is the reverse of the previous embodiment, that is, at the bottom of the column is the component with the lowest proportion, followed by the activated carbon component and at the top, the component present in the highest proportion.

[0034] Stage 5 of crystallization is carried out using conventional crystallization techniques, for example, Petition 870260052979, dated 01 / 06 / 2026, page 25 / 41 16 / 19 by selecting the appropriate solvent for crystallization, adding a solvent, hot filtration of impurities, and cooling the saturated solution contained in a suitable container in an ice bath and / or seeding a crystal of the compound that acts as a crystallization nucleus. Example of evaluating the efficiency of the method.

[0035] 600 grams of pure PP with a known concentration of additives of interest is taken as a reference. Once the material reaches the desired particle size, the column extraction step begins, in which each of the additives of interest is extracted. The 600 grams of the milled polymeric material are transferred to column (1) and solid-liquid extraction is carried out for 2 to 3 hours, using l-methyl-4-(1-methylethenyl)-cyclohexene (limonene) as solvent (I). Column (1) is heated to a temperature of 60°C and energy is applied by ultrasound or microwave radiation. After that, the solvent enriched with the additives extracted in column (1) is subjected to step 4 of packed column extraction, specifically to a packed column separation (1').Next, the solvent and the separated additives are recovered: cis-13-docosenamide (Erucamide), cis-9-octadecenamide (oleamide), and glycerol monostearate-glycerol palmitate (GMS). This process then proceeds to step 5, crystallization, which is carried out according to basic crystallization concepts, followed by the final step 6, quantification of the obtained additives. | In this step, between 90% and 95% of the aforementioned additives are recovered.

[0036] After treatment in column 1 with solvent (I), the polymeric material now called (A'), passes through Petition 870260052979, dated 01 / 06 / 2026, page 26 / 41 17 / 19 column (2), in which solid-liquid extraction is carried out for 2 to 3 hours, using as solvent (II) a mixture of cyclohexane:l-methyl-4-(1-methylethenyl)-cyclohexene (limonene) in proportions ranging from 20:80 to 80:20. Column (2) was heated to a preferred temperature of 60°C and energy is applied by ultrasound or microwave radiation. After that, the solvent enriched with the additives extracted in column (2) is subjected to separation in the packed column (2'). Next, the solvent and the additive octadecyl-3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate (Irganox 107 6) are recovered, which then proceeds to step 5 of crystallization, carried out according to the basic concepts of crystallization, to subsequently proceed to the final step 6 of quantification of the additives obtained, where a recovery of the additive of 70% was achieved.

[0037] After treatment in column (2), the molded polymeric material now called (A) passes through column (3), in which solid-liquid extraction is carried out for 2 to 3 hours, using as solvent (III) a mixture of toluene:cyclohexane in proportions ranging from 20:80 to 80:20. Column (3) is heated to a temperature of 60°C and energy is applied by ultrasound or microwave radiation. After that, the solvent enriched with the additives extracted in column (3) is subjected to separation in the packed column (3). Subsequently, the solvent and the separated additives are recovered: octadecyl-3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate (Irganox 1076), pentaerythritol tetracis(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate) (Irganox 1010), 1,3,5-trimethyl-2,4,6-tris(3,5-di-tert-butyl-4-hydroxybenzyl)benzene (Etanox 330), tris(2,4-diterc Petition 870260052979, dated 01 / 06 / 2026, p. 27 / 41 18 / 19 butylphenyl)phosphite (Irganox 168), bis(2,4-dicumylphenyl)pentaerythritol diphosphite (Doverohos), and 1,3,5-tris(4-tert-butyl-3-hydroxy-2,6-dimethylbenzyl)-1,3,5-triazin-2,4,6(1H,3H,5H)-trione (Cyanox 1790) proceed to step 5 of crystallization, which is carried out according to the basic concepts of crystallization, in order to subsequently proceed to the final step 6 of quantification of the additives obtained, in which the following percentages were found: 20% octadecyl-3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate (Irganox 1076), 80% pentaerythritol tetracis(3-(3,5-ditert-butyl-4-hydroxyphenyl)propionate) (Irganox 1010), 90% 1,3,5-trimethyl-2,4,6-tris(3,5-di-tert-butyl-4hydroxybenzyl)benzene (Etanox 330), 85% tris(2,4-ditert-butylphenyl)phosphite (irgafox 168), 77% bis(2,4dicumylphenyl)pentaerythritol diphosphite (doverohos), 81% 1,3,5-tris(4-tert-butyl-3-hydroxy-2,6-dimethylbenzyl)-1,3,5triazin-2,4,6-(1H,3H,5H)-trione (cyanox 1790).

[0038] After treatment in column (3), the milled polymeric material, now called A', goes to column (4), where solid-liquid extraction is carried out for 2 to 3 hours, using as solvent (IV) a mixture of toluene: l-methyl-4-(1-methylethenyl)-cyclohexene (limonene) in proportions ranging from 20:80 to 80:20. Column (4) is heated to a temperature of 60°C and energy is applied by ultrasound or microwave radiation. After that, the solvent enriched with the additives extracted in column (4) is subjected to separation in the packed column (4). Subsequently, the solvent and the separated additives are recovered: pentaerythritol tetracis(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate) (Irganox 1010), 1,3,5-trimethyl Petition 870260052979, dated 01 / 06 / 2026, page 28 / 41 19 / 19 2,4,6-tris(3,5-di-tert-butyl-4-hydroxybenzyl) benzene (Etanox 330), tris(2,4-ditert-butylphenyl)phosphite (irgafox 168), bis(2,4-dicumylphenyl)pentaerythritol diphosphite (doverohos), 1,3,5-tris(4-tert-butyl-3-hydroxy-2,6-dimethyl benzyl)-1,3,5-triazin-2,4,6-(1H,3H,5H)-trione (cyanox 1790); which then proceed to step 5 of crystallization, which is carried out according to the basic concepts of crystallization, and subsequently to the final step 6 of quantification of the additives, where said additives were found in the following percentages: 10% pentaerythritol tetracis(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate) (Irganox 1010), 5% 1,3,5-trimethyl-2,4,6-tris(3,5-ditert-butyl-4-hydroxybenzyl)benzene (Etanox 330), 5% tris(2,4-ditert-butylphenyl)phosphite (Irganox 168), 10% bis(2,4-dicumylphenyl)pentaerythritol diphosphite (Doverohos), 5% of 1,3,5-tris(4-tert-butyl-3-hydroxy-2,6-dimethyl benzyl)1,3,5-triazin-2,4,6-(1H,3H,5H)-trione (cyanox 1790).

[0039] Step 5 of crystallization is carried out using conventional crystallization techniques, for example, by selecting the appropriate solvent for crystallization, adding the solvent, hot filtration of impurities and cooling the saturated solution contained in a suitable container in an ice bath and / or by seeding a crystal of the compound that acts as a crystallization nucleus.

Claims

CLAIMS 1. Extraction, quantification and recovery process of additives in polypropylene characterized by comprising the following steps: Step 1) washing of a plastic material (A); Step 2) grinding of the plastic material (A) to a particle size between 10 and 500 microns; Step 3) carrying out extraction where the plastic material (A) from step 2) is transferred to a first column and then successively the plastic material (A) passes through a second column, a third column and a fourth column respectively for successive extractions with a first solvent, a second solvent, a third solvent and a fourth solvent, respectively, to obtain a first solvent, a second solvent, a third solvent and a fourth solvent with additives;Step 4) Performing extractions in packed columns, where the first, second, third, and fourth solvents with the additives obtained from each extraction in the first, second, third, and fourth columns of step 3) pass through a first packed column, a second packed column, a third packed column, and a fourth packed column respectively to obtain a first additive, a second additive, a third additive, and a fourth additive; Step 5) Crystallization of the additives obtained after each extraction step in the first, second, third, and fourth packed columns respectively of step 4); and Step 6) Quantification of the crystallized additives obtained from step 5);in which a waste material without additives is subjected to a subsequent pyrolysis process. Petition 870260052979, dated 01 / 06 / 2026, page 30 / 41 2 / 4, wherein in step 4) the first, second, third and fourth packed columns each comprise a different packing, and wherein the first packed column contains 85% to 95% of a modified styrene-divinylbenzene polymer (Strata X-33), 2.5% to 7.5% of activated carbon and 2.5% to 7.5% of silanized glass wool; the second packed column contains 80% to 90% of a modified styrene-divinylbenzene polymer (Strata X33), 7.5% to 15% of activated carbon and 2.5% to 5% of silanized glass wool; The third packed column contains 70% to 90% of a modified styrene-divinylbenzene polymer (Strata X33), 5% to 15% activated carbon, and 5% to 15% silanized glass wool;and the fourth packed column contains 70% to 90% of a modified styrene-divinylbenzene polymer (Strata X33), 5% to 15% activated carbon and 5% to 15% silanized glass wool.

2. Process for extraction, quantification and recovery of additives in polypropylene, according to claim 1, characterized in that step 1) is carried out at a temperature between 20 and 50°C.

3. Extraction, quantification and recovery process of additives in polypropylene, according to claim 1, characterized in that in step 2), grinding is carried out in a crusher or mill and the particle size is between 20 and 200 microns.

4. Extraction, quantification and recovery process of polypropylene additives, according to claim 1, characterized in that in step 3), each column has a controlled heating system, ultrasound system, microwave system or supercritical fluid.

5. Extraction, quantification and recovery process of additives in polypropylene, according to claim 1, characterized in that in step 3), in the first column a solid-liquid extraction is carried out for 2 to 3 hours with the first solvent which is 1-methyl-4-(1-methylethenyl)-cyclohexene (limonene) and the first column is heated to a temperature between 40 and 70°C, and energy is applied by ultrasound or microwave radiation.

6. Extraction, quantification and recovery process of additives in polypropylene, according to claim 1, characterized in that in step 3), the second column contains the second solvent which is a mixture of cyclohexane: 1-methyl-4-(1-methylethenyl)-cyclohexene (limonene) in proportions ranging from 20:80 to 80:20 and the second column is heated to a temperature between 40°C and 70°C, and energy is applied by ultrasound or microwave radiation.

7. Extraction, quantification and recovery process of additives in polypropylene, according to claim 1, characterized in that in step 3), the third column contains the third solvent which is a mixture of toluene:cyclohexane in proportions ranging from 20:80 to 80:20 and the third column is heated to a temperature between 40°C and 70°C, and energy is applied by ultrasound or microwave radiation.

8. Extraction, quantification and recovery process of additives in polypropylene, as claimed in Petition 870260052979, dated 01 / 06 / 2026, page 32 / 41 4 / 4 1, characterized in that in step 3), in the fourth column a solid-liquid extraction is carried out for 2 to 3 hours with the fourth solvent which is a mixture of toluene: 1-methyl-4-(1-methylethenyl)-cyclohexene (limonene) and the fourth column is heated to a temperature between 40°C and 70°C, and energy is applied by ultrasound or microwave radiation.

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