# US 8,785,622 B2 · Crosslinked polysaccharides and methods of production thereof > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,785,622 B2 - Document ID: US8785622B2 - Status: Granted - Kind: B2 - Application number: 12/322,288 - Filed: 2009-01-30 - Published: 2009-08-06 - Granted: 2014-07-22 - Earliest claimed: 2008-01-31 - Assignees: Rhodia Operations - Applicants: Caroline Mabille; Kraig Luczak - Inventors: Caroline Mabille; Kraig Luczak - Web page: https://patentgrep.com/patent/US8785622B2 ## CPC - C07H 1/00: Processes for the preparation of sugar derivatives - C07H: SUGARS; DERIVATIVES THEREOF; NUCLEOSIDES; NUCLEOTIDES; NUCLEIC ACIDS (derivatives of aldonic or saccharic acids C07C, C07D; aldonic acids, saccharic acids C07C59/105, C07C59/285; cyanohydrins C07C255/16; glycals C07D; compounds of unknown constitution C07G; polysaccharides, derivatives thereof C08B; DNA or RNA concerning genetic engineering, vectors, e.g. plasmids, or their isolation, preparation or purification C12N15/00; sugar industry C13) ## Abstract A substantially boron-free method for making a cationic guar comprises reacting particles of polysaccharide with a derivatizing agent to produce derivatized polysaccharide particles, washing the derivatized polysaccharide particles, and contacting, prior to or after the washing step, the particles with a glyoxal compound in order to crosslink the derivatized polysaccharide particles. Also disclosed are methods for making crosslinked derivatized polysaccharides, comprising (a) contacting particles of a polysaccharide with a titanium compound in an aqueous medium having an alkaline pH under conditions appropriate to intra-particulately crosslink the particles; (b) reacting, prior to or after the step of contacting the particles of polysaccharide with the titanium compound, the particles of polysaccharide with a derivatizing agent under conditions appropriate to produce derivatized polysaccharide particles; (c) washing the titanium crosslinked and derivatized particles; (d) contacting, concurrently with or after the step of washing the titanium crosslinked and derivatized particles, such particles with an aqueous medium having an acidic pH under conditions appropriate to substantially de-crosslink the particles; and (e) contacting, concurrently with or after step (d), the de-crosslinked particles with a glyoxal compound under conditions appropriate to intra-particulately crosslink the particles. The crosslinked cationic guar of the present invention is especially useful in home and personal care formulations, especially formulations comprising silicone since it improves silicone deposition. ## Claims ### Claim 1 A method for producing crosslinked derivatized polysaccharides, comprising: (a) contacting particles of a polysaccharide with a titanium compound in an aqueous medium having an alkaline pH under conditions appropriate to intra-particulately crosslink the particles; (b) reacting, prior to or after the step of contacting the particles of polysaccharide with the titanium compound, the particles of polysaccharide with a derivatizing agent under conditions appropriate to produce derivatized polysaccharide particles; (c) washing the titanium crosslinked and derivatized particles; (d) contacting, concurrently with or after the step of washing the titanium crosslinked and derivatized particles, such particles with an aqueous medium having an acidic pH under conditions appropriate to substantially de-crosslink the particles; and (e) contacting, concurrently with or after step (d), the de-crosslinked particles with a glyoxal compound under conditions appropriate to intra-particulately crosslink the particles. ### Claim 2 (depends on 1) The method of claim 1 wherein the titanium compound is selected from the group consisting of titanium salts, titanium chelates and titanium esters. ### Claim 3 The method of 1 wherein the titanium compound is selected from the group consisting of titanium tetrachloride, titanium tetrabromide, tetra amino titanate, titanium acetylacetonate, triethanolamine titanate, titanium lactate, n-butyl polytitanate, titanium tetrapropanolate, octyleneglycol titanate, tetra-n-butyl titanate, tetra-2-ethylhexyl titillate, tetra-isopropyl titanate, diisopropyl di-triethanolamino titanate, titanium ortho ester, titanium (IV) chloride and mixtures thereof. ### Claim 4 (depends on 1) The method of claim 1 wherein contacting the titanium crosslinked and derivatized particles with an aqueous medium in step (d), contacting the de-crosslinked particles with a glyoxal compound in step (e) or both is performed through a spraying process. ### Claim 5 (depends on 1) The method of claim 1 wherein about 0.01 to about 30 parts by weight of the glyoxal compound per 100 parts by weight of the derivatized polysaccharide particles is utilized to intra-particulately crosslink the particles. ### Claim 6 (depends on 5) The method of claim 5 wherein about 0.1 to about 30 parts by weight of the glyoxal compound per 100 parts by weight of the derivatized polysaccharide particles is utilized to intra-particulately crosslink the particles. ### Claim 7 (depends on 1) The method of claim 1 wherein the contacting of particles of polysaccharide with the titanium compound in step (a) occurs after the reacting of the particles of polysaccharide with the derivatizing agent in step (b). ### Claim 8 (depends on 1) The method of claim 1 wherein the aqueous medium having an acidic pH comprises a Bronsted acid. ### Claim 9 (depends on 8) The method of claim 8 wherein the Bronsted acid is citric acid. ### Claim 10 (depends on 1) The method of claim 1 wherein the derivatized polysaccharide particle is a derivatized guar particle. ### Claim 11 (depends on 10) The method of claim 10 wherein the derivatized guar particle is selected from the group consisting of hydroxypropyl guar, carboxymethyl guar, hydroxyethyl guar, carboxymethylhydroxypropyl guar, hydroxybutyl guar, cationic guar, hydrophobically modified guar, hydrophobically modified carboxymethyl guar, hydrophobically modified hydroxyethyl guar, hydrophobically modified hydroxypropyl guar, hydrophobically modified carboxymethylhydroxypropyl guar, hydrophobically modified hydroxybutyl guar, and hydrophobically modified cationic guar. ### Claim 12 (depends on 1) The method of claim 1 further comprising: (f) washing the glyoxal crosslinked and derivatized particles concurrently with or after step (e). ### Claim 13 (depends on 1) The method of claim 1 wherein the step of contacting particles of a polysaccharide with a titanium compound is conducted in an aqueous medium having a pH greater than 10 under conditions appropriate to intra-particulately crosslink the particles. ### Claim 14 (depends on 13) The method of claim 13 wherein the step (e) comprises contacting the de-crosslinked particles with a glyoxal compound in an aqueous medium having a pH less than 7 under conditions appropriate to intra-particulately crosslink the particles. ### Claim 15 (depends on 13) The method of claim 13 wherein contacting the titanium crosslinked and derivatized particles with an aqueous medium in step (d), contacting the de-crosslinked particles with a glyoxal compound in step (e) or both is performed through spraying.