# US 11,992,787 B2 · Reducing surface and bulk contamination in plastic > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,992,787 B2 - Document ID: US11992787B2 - Status: Granted - Kind: B2 - Application number: 18/127,086 - Filed: 2023-03-28 - Published: 2023-08-10 - Granted: 2024-05-28 - Earliest claimed: 2020-04-15 - Assignees: The Procter & Gamble Company - Applicants: The Procter & Gamble Company - Inventors: Norman Scott Broyles; Dimitris Ioannis Collias; Anthony Frederick Cappel - Web page: https://patentgrep.com/patent/US11992787B2 ## CPC - B01D 11/0288: {Applications, solvents} - B01D 11/0203: {with a supercritical fluid} - B08B 3/04: Cleaning involving contact with liquid - B29B 17/00: Recovery of plastics or other constituents of waste material containing plastics; ({volume reduction of waste plastics, e.g. by mechanical compacting or melting disposal of solid waste B09B;} chemical recovery C08J11/00) - C08J 11/08: using selective solvents for polymer components - B01D 11/0292: {Treatment of the solvent} - B08B 2220/00: Type of materials or objects being removed - B08B 2240/00: Type of materials or objects being cleaned - B29B 2017/0015: {Washing, rinsing} - B29B 2017/0289: {Washing the materials in liquids} - B29B 2017/0293: {Dissolving the materials in gases or liquids} - B29K 2105/26: Scrap {or recycled material} - C08J 7/02: with solvents, e.g. swelling agents - C08J 2300/30: Polymeric waste or recycled polymer - Y02W 30/62: Plastics recycling; Rubber recycling - B01D: SEPARATION (separating solids from solids by wet methods B03B, B03D; by pneumatic jigs or tables B03B; by other dry methods B07; magnetic or electrostatic separation of solid materials from solid materials or fluids, separation by high-voltage electric fields B03C; centrifuges, vortex apparatus B04; presses per se for squeezing-out liquid from liquid-containing material B30B9/02; treatment of water C02F, e.g. softening by ion-exchange C02F1/42; {arrangements of air intake cleaners in gas turbine plants F02C7/05} ; arrangements or mounting of filters in air-conditioning, air-humidification or ventilation F24F13/28) - B08B: CLEANING IN GENERAL; PREVENTION OF FOULING IN GENERAL - B29B: PREPARATION OR PRETREATMENT OF THE MATERIAL TO BE SHAPED; MAKING GRANULES OR PREFORMS; RECOVERY OF PLASTICS OR OTHER CONSTITUENTS OF WASTE MATERIAL CONTAINING PLASTICS - C08J: WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H (working, e.g. shaping, of plastics B29) - B29K: INDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS OR TO MATERIALS FOR {MOULDS, } REINFORCEMENTS, FILLERS OR PREFORMED PARTS, e.g. INSERTS - Y02W: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO WASTEWATER TREATMENT OR WASTE MANAGEMENT ## Abstract The present invention generally relates to a method of reducing contamination from plastics. The resulting purer plastic can be used in demanding applications. ## Claims ### Claim 1 A method to extract contaminates from a first plastic to produce a purer plastic comprising: a. providing a first plastic comprising individual contaminants, each individual contaminant having a concentration; b. extracting said individual contaminates from said first plastic at a temperature and a pressure, using ethyl acetate, in extraction stages, wherein the total extraction time is less than about 6 hours, to produce a purer plastic comprising individual contaminates, each having a concentration; wherein said extraction is flooded leaching wherein said temperature is between about 20 and 90 C; wherein said extraction stages are conducted at an ethyl acetate to first plastic mass ratio; wherein said ethyl acetate to first plastic mass ratio per stage at any time is less than 100:1; wherein said pressure is between about atmospheric and 1,000 atm; wherein said first plastic individual contaminants comprise at least one of 4-tertpentylphenol, bisphenol A, OCDD, PCB 118, and 2-ethylhexyl phthalate; wherein each individual contaminants concentration in said purer plastic is reduced compared to each individual contaminants concentration in said first plastic; and wherein the average of said reductions of said concentrations of said first plastic contaminants to said purer plastic contaminants is at least about 55% or LOQ; and wherein ethyl acetate should not significantly dissolve the first plastic at the temperature and pressure of the process. ### Claim 2 (depends on 1) The method of claim 1, wherein said number of stages is between about 1 and about 50. ### Claim 3 (depends on 1) The method of claim 1, wherein said first plastic is a reclaimed plastic comprising at least one of a post-industrial or post-consumer film. ### Claim 4 (depends on 1) The method of claim 1, wherein said first plastic has a mass average surface area to volume ratio of at least about 1 mm-1. ### Claim 5 (depends on 1) The method of claim 1, wherein said first plastic is surface washed in a non-densified state by a surface washing process or processes prior to extraction and wherein said surface washing process or processes results in a greater than about an 80% reduction in loosely bound surface contamination; wherein said first plastic prior to surface washing has a surface area to volume ratio of greater than about 1 mm-1. ### Claim 6 (depends on 5) The method of claim 5, wherein said surface washing process is of the de-inking type; wherein said de-inking process results in a delta E percent change of less than about 10% between the de-inked first plastic and the first plastic without surface printed ink. ### Claim 7 (depends on 1) The method of claim 1, wherein said leaching solvent is purified after said flooded leaching or said flooded leaching stage or stages to allow re-use in the flooded leaching process by a solvent purification process or processes; wherein said solvent purification process or processes comprises at least one stage of physical adsorption or absorption of the chemical contaminants from the contaminated leaching solvent. ### Claim 8 (depends on 1) The method of claim 1, wherein said first plastic is a reclaimed plastic that is at least one of a post-industrial or post-consumer film; wherein said post-consumer film includes post-commercial film and/or post-household film. ### Claim 9 (depends on 1) The method of claim 1, wherein said pressure is about atmospheric. ### Claim 10 (depends on 9) The method of claim 9, wherein said temperature is about the normal boiling point of ethyl acetate. ### Claim 11 (depends on 1) The method of claim 1, wherein said pressure is above atmospheric. ### Claim 12 (depends on 11) The method of claim 11, wherein said temperature is above the critical temperature of ethyl acetate. ### Claim 13 (depends on 1) The method of claim 1; wherein said first plastic is surface washed in a non-densified state by a surface washing process or processes prior to extraction and wherein said surface washing process or processes results in a greater than about an 80% reduction in loosely bound surface contamination comprising at least one of 4-tertpentylphenol, bisphenol A, OCDD, PCB 118, and 2-ethylhexyl phthalate; wherein said first plastic prior to surface washing has a surface area to volume ratio of greater than about 1 mm-1. ### Claim 14 (depends on 1) The method of claim 1; wherein said first plastic is surface washed in a non-densified state by a surface washing process or processes prior to extraction and wherein said surface washing process or processes results in a greater than about an 80% reduction in loosely bound surface contamination comprising at least one of 4-tertpentylphenol, bisphenol A, OCDD, PCB 118, and 2-ethylhexyl phthalate; wherein said first plastic prior to surface washing has a surface area to volume ratio of greater than about 1 mm-1; wherein said surface washing process is of the de-inking type; wherein said de-inking process results in a delta E percent change of less than about 10% between the de-inked first plastic and the first plastic without surface printed ink.