Classifications

• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
  • C08K3/00—Use of inorganic substances as compounding ingredients
  • C08K3/32—Phosphorus-containing compounds
• • C—CHEMISTRY; METALLURGY
  • C01—INORGANIC CHEMISTRY
  • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
  • C01B25/00—Phosphorus; Compounds thereof
  • C01B25/16—Oxyacids of phosphorus; Salts thereof
  • C01B25/165—Hypophosphorous acid; Salts thereof
• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
  • C07C211/00—Compounds containing amino groups bound to a carbon skeleton
  • C07C211/62—Quaternary ammonium compounds
  • C07C211/63—Quaternary ammonium compounds having quaternised nitrogen atoms bound to acyclic carbon atoms
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
  • C08K5/00—Use of organic ingredients
  • C08K5/16—Nitrogen-containing compounds
  • C08K5/17—Amines; Quaternary ammonium compounds
  • C08K5/19—Quaternary ammonium compounds
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
  • C08K3/00—Use of inorganic substances as compounding ingredients
  • C08K3/32—Phosphorus-containing compounds
  • C08K2003/329—Phosphorus containing acids

Definitions

• the present invention concerns a process for the production of a hypophosphite salt using at least P4 and a catalyst.
• Base that can be used is preferably a hydroxide salt or a hydroxide salt precursor that can also be used as catalyst of the instant invention.
• hypophosphite salts and, especially, calcium hypophosphite can be prepared for example from white phosphorus (P4) reacted under alkaline conditions with calcium hydroxide or calcium oxide and water as taught by US5225052. It is also possible to obtain calcium hypophosphite by reaction of a calcium salt or simply from lime as taught by Chinese patent CN101332982, with hypophosphorous acid. For example the lime suspension is simply neutralized with hypophosphorous acid, the impurities are removed by filtration and the product isolated in a same way as previously described. It is also possible to obtain calcium hypophosphite from other metallic hypophosphites or the acid by ion exchange process.
• the present invention concerns a process for the production of a hypophosphite salt using at least P4 and a catalyst.
• the present invention then concerns a process to produce a hypophosphite salt defined as [C + Hypophosphite " ] by reacting P4 with a hydroxide salt, defined as [C + OH " ], or a hydroxide salt precursor; and a catalyst; wherein C + is the cationic moiety of [C + Hypophosphite " ] salt.
• reaction of the instant invention may be established as follows : [C + OH] + P4 -> [C + Hypophosphite ' ]
• This process permits then to produce hypophosphite salts, but also phosphate salts as a by product.
• Such a process according to the present invention permits to obtain a molar ratio of hypophosphite salt / phosphite salt superior to 1.5 ; preferably superior or equal to 1.6, more preferably superior or equal to 1.7, notably superior or equal to 2.0; permitting thereof to increase the selectivity of the reaction.
• the invention also concerns a blend of hypophosphite salts and phosphate salts susceptible to be obtained by the process of the present invention.
• salts are ionic compounds that result from the neutralization reaction of an acid and a base. There are composed of cations that are positively charged ions and anions that are negative ions; so that the product is electrically neutral.
• P 4 is the tetraphosphorus, also called “white phosphorus", consisting of six single P-P bonds.
• Catalyst as defined in the invention is a substance changing the rate of the reaction of the invention without being consumed by the reaction itself, contrarily to the other reagents.
• catalysts are preferably quaternary ammonium salts or phosphonium salts.
• the quaternary ammonium salt catalyst of the present invention is a quaternary ammonium salt of formula (I) wherein:
• R 1 , R 2 , R 3 and R 4 independently of one another represent an organic hydrocarbon group
• X is an organic or an inorganic anion.
• R 1 , R 2 , R 3 and R 4 independently of one another preferably represent a branched or unbranched alkyl group having 1-18 carbon atoms, more preferably having 1-6 carbon atoms.
• R 1 , R 2 , R 3 and R 4 independently of one another can also represent an aryl, alkylaryl or arylalkyl group having 6-18 carbon atoms, more preferably having 6-10 carbon atoms.
• Said organic hydrocarbon group may be branched or unbranched, saturated or unsaturated. Said group can notably be an aliphatic or an aromatic group.
• R , R 2 , R 3 and R 4 independently of one another preferably represent an afkyl group having 1-6 carbon atoms, such as methyl, ethyl, propyl, and butyl.
• X is an organic or an inorganic anion that may be OH, a halogen atom, a sulfate, a carbonate or an alkylate.
• Halogen atom may be for example F, CI, Br or I.
• Alkylate anions may be for example acetate.
• X is preferably an OH or a halogen such as CI or Br.
• Compounds of formula (I) are preferably chosen in the group consisting of: tetrabutylammonium hydroxide, tetrabutylammonium chroride, tetrabutylammonium bromide, benzalkonium chloride, tetraethylammonium hydroxide, tetramethylammonium chloride , tetramethylammonium hydroxide, tetraethylammonium bromide, cetrimonium bromide, dimethyldioctadecylammonium chloride, benzyltrimethylammonium chloride, benzyltrimethylammonium bromide, tetrabutylammonium acetate, and tetrapropylammonium hydroxide.
• Preferred molar proportions of catalyst may be comprised between 0.1 and 40 %, in relation with the mol of P4.
• Preferred molar proportions of catalyst may be comprised between 0.1 and 40 %, in relation with the mol of [C + OH ' ].
• Preferred molar proportions of quaternary ammonium salt are comprised between 10 and 40 %, in relation with the mol of P4.
• C + is the cationic moiety of [C + Hypophosphite " ] salt; that may represent an inorganic element such as a metal, an alkali earth metal, an alkali metal or a quaternary ammonium salt or quaternary phosphonium salt.
• C + is preferably an alkali earth metal, such as Ca or Mg, or an alkali metal, such as Li, Na or K, a quaternary ammonium salt or quaternary phosphonium salt.
• hydroxide salt precursor of [C + OH " ] may be used in the process of the invention.
• Such hydroxide salt precursor can be for example an oxide precursor, such as calcium oxide permitting to obtain calcium hydroxide, in presence of water.
• [C + OH " ] may be the catalyst used in the reaction, such as for example the quaternary ammonium salt as catalyst of formula (I).
• the preferred molar ratio [C + OH " ]/ P4 is comprised between 0.5 and 4, more preferably between 1.0 and 2.0.
• hypophosphite salt present in the composition according to the invention is preferably a compound of the formula (II) as defined below : C n+ (II) wherein :
• n is comprised between 1 and 5, more preferably 1 , 2 or 3 ;
• C is a cation, preferably an alkali earth metal, such as Ca or Mg, or an alkali metal, such as Li, Na or K, a quaternary ammonium salt or quaternary phosphonium salt.
• hypophosphite salt is more preferably chosen in the group consisting of: sodium hypophosphite, tetrabutylammonium hypophosphite, tetramethylammonium hypophosphite, tetramethylammonium hypophosphite, calcium hypophosphite, aluminium hypophosphite, lanthanum hypophosphite, and cesium hypophosphite.
• Reaction of the present invention can occur at a temperature comprised between 50 and 150°C, preferably comprised between 80 and 120°C. Pressure during the reaction may be between 0.5 and 1.5 bar as example.
• Process of the present invention may be carried out without or with a solvent.
• Preferred solvents are polar solvent such as water or alcohols.
• pH of the reaction is generally alkaline, that is superior to 7; notably comprised between 7.1 and 14.
• the quality of the hypophosphite salts may be determined by detecting the remaining impurities using thermal analysis tools such as ARC (Adiabatic Reaction Calorimeter) and TGA ⁇ Thermal Gravimetric Analysis).
• thermal analysis tools such as ARC (Adiabatic Reaction Calorimeter) and TGA ⁇ Thermal Gravimetric Analysis).
• reaction of the present invention may be carried out in a continuous, semi-continuous or discontinuous way.
• Said reaction may be made as example in a stirring reactor, a stirring reactor with a condenser, a tubular reactor, or a plug flow reactor.
• hypophosphite salt as produced in the present invention may be further stabilized, notably for its use in the field of plastic.
• a process for stabilizing said hypophosphite salt may comprise the steps of:
• hypophosphite salt at least one time, preferably 2 or 3 times, under a controlled value of pH comprised between 4 and 11 , preferably between 5 and 8, said hypophosphite salt being in an aqueous solution and/or in a solid state, and eventually washing at least one time the hypophosphite salt with an organic solvent miscible with water;
• step (b) drying the hypophosphite salt as obtained after the washing operation(s) of step (a) under reduced pressure to remove the volatiles.
• the starting hypophosphite sait which is used in step a) can be in the form of an aqueous solution, charged in a reactor and mixed with a mineral or an organic acid to obtain a slurry whose pH is set at a value of between 4 and 6.5, preferably 5 and 6.
• the acid used in this connection is preferably selected from the group comprising hypophosphorous acid, citric acid, maleic acid, acetic acid, chlorhydric acid and sulphuric acid and, more preferably, the acid is hypophosphorous acid.
• the starting hypophosphite salt of step a) may alternatively be in the form of an aqueous solution, charged in a reactor and mixed with a mineral or an organic base to obtain a slurry whose pH is set at a value of between 7.5 and 11 , preferably 8 and 10.
• the base is preferably selected from the group comprising sodium hydroxide, potassium hydroxide, calcium hydroxide, calcium oxide, magnesium oxide and magnesium hydroxide, even more preferably, the base is calcium hydroxide and/or calcium oxide.
• the process for stabilizing the hypophosphite salt can be batch, continuous or semi-continuous and be performed in a close or open system under inert atmosphere.
• That inert atmosphere can be for example carbon dioxide, argon, or nitrogen.
• the process for stabilizing the hypophosphite salt can be performed under atmospheric pressure, under pressure or under vacuum.
• a way to check the quality of the heat stabilized hypophosphite salt used in the instant invention is to perform a stability test at elevated temperature on the product, alone or mixed with plastic and measure the amount of phosphine generated during the test. It is also possible to measure the amount of phosphine generated when the product is compounded with plastics such as polyamide.
• Hypophosphite salt produced according to the present invention may notably be used as flame retardant agent in polymer compositions, preferably in thermoplastic polymer compositions.
• the invention then also concerns a thermoplastic composition comprising at least a hypophosphite salt as produced with the process as described.
• the polymer present in a flame retardant polymer composition of the invention is selected from the group consisting in polyphenylene ethers, polyamides, polyesters, polycarbonates, epoxy resins, phenolic resins, acrylonitrile butadiene styrene (ABS), styrene acrilonitrile (SAN), polystyrene such as high impact polystyrene (H!PS), polyphenylene ethers such as PPO, styrene butadiene rubber (SBR), halogenated polymers such as polyvinylchloride (PVC), and mixtures and blends of these polymers.
• polyphenylene ethers polyamides, polyesters, polycarbonates, epoxy resins, phenolic resins, acrylonitrile butadiene styrene (ABS), styrene acrilonitrile (SAN), polystyrene such as high impact polystyrene (H!PS), polyphen
• Polyamides are preferably PA66, PA6, PA11 , PA12, PA6.10, high temperature polyamides such as PPA, PA4.6, PA9T, PA66.6T, PA10T, PA6.6T and blends of polyamides, such as PA/PET, PA/ABS or PA/PP.
• Polyesters may be polyethylene terephthalate (PET) or polybutylene terephthalate (PBT).
• reaction mixture was cooled down. After using concentrated HCI to dissolve all solid, 0.4 g H 3 P0 4 (85%) was added as internal standard of P-NMR. P-NMR analysis showed this mixture contained 38.4% hypophosphite and 18.5% phosphate with ratio of 2.1

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• Health & Medical Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Medicinal Chemistry (AREA)
• Polymers & Plastics (AREA)
• Inorganic Chemistry (AREA)
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• 2012
  • 2012-04-06 WO PCT/CN2012/073582 patent/WO2013149396A1/en not_active Ceased
  • 2012-04-06 KR KR1020147030501A patent/KR101979057B1/ko not_active Expired - Fee Related
  • 2012-04-06 CA CA2868035A patent/CA2868035A1/en not_active Abandoned
  • 2012-04-06 CN CN201280072062.2A patent/CN104936891B/zh not_active Expired - Fee Related
  • 2012-04-06 JP JP2015503725A patent/JP5992601B2/ja not_active Expired - Fee Related
  • 2012-04-06 US US14/389,390 patent/US9976010B2/en not_active Expired - Fee Related
  • 2012-04-06 EP EP12873851.5A patent/EP2834190A4/en not_active Withdrawn

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