# US 11,999,925 B2 · Plastic cleaning method using dispersant copolymer > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,999,925 B2 - Document ID: US11999925B2 - Status: Granted - Kind: B2 - Application number: 17/057,263 - Filed: 2019-06-10 - Published: 2021-10-07 - Granted: 2024-06-04 - Earliest claimed: 2018-06-27 - Assignees: Rohm and Haas Company - Applicants: Rohm and Haas Company - Inventors: Scott Backer; Paul Mercando - Web page: https://patentgrep.com/patent/US11999925B2 ## CPC - C11D 3/2093: {Esters; Carbonates} - C11D 1/66: Non-ionic compounds {(C11D1/002, C11D1/004, C11D1/008 take precedence)} - C11D 3/2082: {Polycarboxylic acids-salts thereof} - C11D 3/361: {Phosphonates, phosphinates or phosphonites} - C11D 3/3757: {(Co)polymerised carboxylic acids, -anhydrides, -esters in solid and liquid compositions} - C11D 2111/18: Glass; Plastics - C11D: DETERGENT COMPOSITIONS; USE OF SINGLE SUBSTANCES AS DETERGENTS; SOAP OR SOAP-MAKING; RESIN SOAPS; RECOVERY OF GLYCEROL ## Abstract A plastic cleaning method for cleaning a plastic article in an automatic dishwashing machine is provided, comprising: selecting an automatic dishwashing composition for cleaning plastic, wherein the automatic dishwashing composition, comprises: a builder; a phosphonate a nonionic surfactant; and a dispersant polymer comprising: (a) 60 to 98 wt % of structural units of formula I wherein each R1 is independently selected from a hydrogen and a —CH3 group; and (b) 2 to 40 wt % of structural units of formula II wherein each R2 is independently selected from an alkyl group with at least 4 carbon atoms and wherein each R3 is independently selected from a hydrogen and a methyl group. ## Claims ### Claim 1 A plastic cleaning method for cleaning a plastic article in an automatic dishwashing machine, comprising: selecting an automatic dishwashing composition for cleaning plastic, wherein the automatic dishwashing composition, comprises: a builder, wherein the builder includes a mixture of at least one carbonate and at least one citrate; a phosphonate; a nonionic surfactant; and a dispersant polymer comprising: (a) 85 to 91 wt % of structural units of formula I wherein each R1 is independently selected from a hydrogen and a —CH3 group; and (b) 9 to 15 wt % of structural units of formula II wherein each R2 is independently selected from an alkyl group with at least 4 carbon atoms and wherein each R3 is independently selected from a hydrogen and a methyl group; providing a plastic article, wherein the plastic article includes a polystyrene tumbler; and, applying the automatic dishwashing composition to the plastic article. ### Claim 2 (depends on 1) The plastic cleaning method of claim 1, wherein the plastic article is a plurality of plastic articles. ### Claim 3 (depends on 2) The plastic cleaning method of claim 2, wherein the automatic dishwashing composition is selected to contain less than 0.1 wt %, based on the dry weight of the automatic dishwashing composition, of phosphate, measured as elemental phosphorus. ### Claim 4 (depends on 3) The plastic cleaning method of claim 3, wherein the dispersant polymer is selected to have a weight average molecular weight, MW, of 1,200 to 50,000 Daltons. ### Claim 5 (depends on 4) The plastic cleaning method of claim 4, wherein the automatic dishwashing composition is selected to contain 0 wt %, based on the dry weight of the automatic dishwashing composition, of builders selected from the group consisting of nitrilotriacetic acid; ethylenediaminetetraacetic acid; diethylenetriaminepentaacetic acid; glycine-N,N-diacetic acid; methyl glycine-N,N-diacetic acid; 2-hydroxyethyliminodiacetic acid; glutamic acid-N,N-diacetic acid; 3-hydroxy-2,2′-iminodissuccinate; S,S-ethyl enediaminedisuccinate aspartic acid-diacetic acid; N,N′-ethylene diamine disuccinic acid; iminodisuccinic acid; aspartic acid; aspartic acid-N,N-diacetic acid; beta-alaninediacetic acid; polyaspartic acid; salts thereof and mixtures thereof. ### Claim 6 (depends on 2) The plastic cleaning method of claim 2, wherein the automatic dishwashing composition is selected to further comprises an additive selected from the group consisting of a bleaching agent, a bleach activator, an enzyme, a filler, and mixtures thereof. ### Claim 7 (depends on 1) The plastic cleaning method of claim 1, wherein the automatic dishwashing composition is selected to comprise: 50 to 85 wt % of the builder; 1.5 to 7.5 wt % of the nonionic surfactant; and 2 to 6 wt % of the dispersant polymer; wherein the dispersant polymer comprises: (a) 85 to 91 wt % of structural units of formula I wherein R1 is a hydrogen in at least 98 mol % of the structural units of formula I; and (b) 9 to 15 wt % of structural units of formula II wherein R2 is a butyl group in at least 98 mol % of the structural units of formula II and wherein R3 is a hydrogen in at least 98 mol % of the structural units of formula II; and wherein the dispersant polymer has a weight average molecular weight, MW, of 1,750 to 17,500 Daltons.