Classifications

• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
  • C08G18/00—Polymeric products of isocyanates or isothiocyanates
  • C08G18/06—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen
  • C08G18/28—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen characterised by the compounds used containing active hydrogen
  • C08G18/40—High-molecular-weight compounds
  • C08G18/63—Block or graft polymers obtained by polymerising compounds having carbon-to-carbon double bonds on to polymers
  • C08G18/632—Block or graft polymers obtained by polymerising compounds having carbon-to-carbon double bonds on to polymers onto polyethers
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
  • C08G18/00—Polymeric products of isocyanates or isothiocyanates
  • C08G18/06—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen
  • C08G18/28—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen characterised by the compounds used containing active hydrogen
  • C08G18/30—Low-molecular-weight compounds
  • C08G18/38—Low-molecular-weight compounds having heteroatoms other than oxygen
  • C08G18/3819—Low-molecular-weight compounds having heteroatoms other than oxygen having nitrogen
  • C08G18/3842—Low-molecular-weight compounds having heteroatoms other than oxygen having nitrogen containing heterocyclic rings having at least one nitrogen atom in the ring
  • C08G18/3851—Low-molecular-weight compounds having heteroatoms other than oxygen having nitrogen containing heterocyclic rings having at least one nitrogen atom in the ring containing three nitrogen atoms in the ring
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
  • C08G18/00—Polymeric products of isocyanates or isothiocyanates
  • C08G18/06—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen
  • C08G18/28—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen characterised by the compounds used containing active hydrogen
  • C08G18/40—High-molecular-weight compounds
  • C08G18/409—Dispersions of polymers of C08G in organic compounds having active hydrogen
• • 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
  • C08K5/34—Heterocyclic compounds having nitrogen in the ring
  • C08K5/3467—Heterocyclic compounds having nitrogen in the ring having more than two nitrogen atoms in the ring
  • C08K5/3477—Six-membered rings
  • C08K5/3492—Triazines
  • C08K5/34922—Melamine; Derivatives thereof
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
  • C08G2110/00—Foam properties
  • C08G2110/0008—Foam properties flexible

Definitions

• This invention relates to a stable dispersion of melamine in a polymer polyol an
• Polyurethane by nature of being an organic polymer when subjected to sufficient heat in an oxygen- containing environment will burn. For many applications it is desirable to reduce or retard the burning characteristics of such polymer by incorporating a flame retardant.
• flame retardants for this purpose include phosphorus
• halogen-containing compounds such as, for example, tris(chloroethyl)phosphonate (TCEP) and dimethoxymethyl phosphonate (DMMP).
• TCEP tris(chloroethyl)phosphonate
• DMMP dimethoxymethyl phosphonate
• nitrogen-containing compounds notably melamine, may be used to prepare combustion-modified polyurethanes.
• U.S. Patent 4,892,893 discloses use of melamine, present in an amount of from 5 to 25 percent based on total weight of the flexible foam, having a mean particle size of from 25 to 500 microns, and to impart resistance to cigarette smoldering ignition of flexible polyurethane foam. According to these patents, the melamine is incorporated into the polyol
• U.S. Patent 4,293,697 discloses a stabilized dispersion of melamine in a polyether
• At least 90 percent of the melamine particles have a mean size of less than 10 microns and are stabilized as a dispersion in the polyol by the presence of silicic acids and silicates, salts of perfluorinated alkyl carboxylic acids, salts of alkyl sulfonic acids and perfluorinated alkyl sulfonic acids, polyperfluorate polyols and salts of aliphatic alcohol sulphates.
• Small melamine particle size is not favorable for use where a high loading of melamine in the foam is required to provide the desirable degree of flame retardation. High loadings of small particle sized melamine frequently result in poor quality or unstable foams.
• U.S. Patent 4,644,015 discloses stabilized dispersions of melamine in standard polyetherpolyolsfor use in preparing flexible polyurethane foam.
• the melamine particles having a mesh size of greater than 325 that is less than 45 microns, being stabilized by the presence of an amine compound consisting of diethanolamine, ethanolam ⁇ ne ortrihexylamine.
• the presence of such amine compound in the amounts required to provide a stabilized dispersion is not desirable when preparing polyurethane foam especially in the presence of water.
• Such amine compounds possess catalytic properties leading to system reactivities which are too quick for many commercial foam producers.
• the furniture industry desires foams exhibiting enhanced load bearing properties.
• a convenient means of achieving the desirable load bearing characteristics of flexible foam is to use a filler or polymer polyol in its preparation.
• Polymer polyols are distinguishable from conventional polyether polyolsj ⁇ that they have suspended therein a discrete organic polymer.
• Illustrative of polymer polyol types are those wherein the suspended organic polymer is a styrene:acrylonitrile (SAN) copolymer, a polyurea adduct(PHD), a polyisocyanate-potyamine adduct (PIPA) or an epoxy resin.
• SAN styrene:acrylonitrile
• PPD polyurea adduct
• PIPA polyisocyanate-potyamine adduct
• this invention is a stable dispersion which comprises:
• (b) from 20 to 60 percent based on the total weight of (a) and (b), of melamine which has a mean particle size of from at least 10 to 125 microns;
• this invention is a process for preparing a stable dispersion as described in the first aspect.
• this invention is a polyurethane polymer obtainable by contacting under reaction conditions an organic isocyanate with an isocyanate reactive composition which contains a stable dispersion as claimed in Claim 1 wherein the organic polyisocyanate is present in an amount to provide from 0.85 to 1.25 isocyanate groups per isocyanate reactive hydrogen atom present characterized in that the polymer has dispersed therein: from 2 to 30 percent based on total weight of polymer of melamine that has a mean particle size of from at least 10 to 125 microns; from 0.1 to 2.5 percent based on total weight of polymer of an inorganic particulate solid which has an average particle size of from 5 to 30 nanometers; and from 2 to 25 weight percent of a polymer solid.
• Such above-described melamine polymer polyol dispersions are stable. Additionally, such stabilized dispersions can be conveniently processed to provide flexible polyurethane foam exhibiting desirable combustion-modified characteristics and overall commercially attractive physical properties.
• the stable dispersion of this invention has a continuous phase comprising a polyol having suspended therein an organic polymer solid and having further dispersed therein melamine particles and an inorganic particulate solid (sometimes referred to hereinafter as IPS).
• IPS inorganic particulate solid
• stable it is understood that when the dispersion is stored at room temperature, ' without agitation, the melamine essentially remains dispersed in the continuous phase with little or no sedimentation being observed. If sedimentation should occur the dispersion of this invention may be characterized in that only a minimum of effort is required to redisperse the melamine due to the presence of the IPS. Generally little or no melamine sedimentation will occur within the first 2 weeks after preparation of the dispersion. Depending on the amount of IPS present, frequently little or no melamine sedimentation may occur in the first 12 or even first 20 weeks after preparation of the dispersion.
• the continuous phase of the stable dispersion comprises a polyether polyol or mixture of polyether polyols containing from 4 to 50 weight percent of a polymer solid.
• a polyether polyol or mixture of polyether polyols containing from 4 to 50 weight percent of a polymer solid.
• such polyol contains the polymer solid in an amount of from-4 to 30, more preferably from 5 to 20 percent.
• Polyol containing a higher solids content than this will generally be highly viscous and difficult to manage; a lower solids content normally will not provide for any noticeable effect when incorporated into a polyurethane polymer.
• a polyether polyol containing such solid is generally referred to as a "polymer polyol".
• the continuous phase comprises such a polymer polyol in an amount of at least 50, preferably at least 60, and more preferably at least 75 weight percent of the continuous phase.
• the continuous phase is not constituted in its entirety by the polymer polyol the remaining percentage may be constituted by other conventional polyoxyalkylene polyols used in the preparation of polyurethane polymers.
• Suitable polyols containing an organic polymer solid for use in this present invention include SAN-, PHD- and PIPA-type polymer polyols. Processes for obtaining suitable PHD- and PIPA-type polymer polyols are disclosed in U.S.
• Patents 4,374,209; 3,325,421; 4,042,537 and 4,093,567 Processes for obtaining suitable SAN copolymer polyols for use in this present invention are described in U.S. Patents 3,385,351 ; 3,304,273; 3,523,093 and 3,110,695.
• the polyol of the continuous phase has an average of from 2 to 4 isocyanate-reactive groups per molecule; an average hydroxyl equivalent weight of from 750 to 3000, preferably at least 1000, more preferably at least 1200; and preferablyat most 2500, more preferably at most 2000. Additionally it is advantageous forthe polyol to have a primary hydroxyl content of from at I east 10, preferably from at least 30, and more preferably from at least 50 percent of its total hydroxyl content. Use of a polyol having such characteristics generally provides for a flexible polyurethane foam with desirable physical properties.
• the continuous phase comprises a SAN polymer polyol, and more preferably consists essentially of a SAN polymer polyol.
• SAN polymer polyols include those sold by The Dow Chemical Company and include the products designated as VORANOL TM CP-8020, VORANOL" CP-8010, VORANOL” CP-8030,and products designated as VORALUX TM in conjunction with the designation codes H N200 through to H N206.
• the melamine dispersed within the continuous phase is characterized in that it has a mean particle size of from 10to 125 microns.
• the melamine particle size is preferably at least 25, more preferably at least 40 and most preferably at least 50 microns, and preferably at most 100, more preferably at most 90 microns.
• Melamine having such a particle size is readily available commercially and may be obtained and used directly without the need for particle size reduction through milling, grinding or such like techniques.
• Use of melamine having a smaller particle size than defined provides mixtures whose viscosity is undesirably high for convenient processing and preparation of polyurethane foam.
• the stable dispersion of the present invention comprises the melamine in an amount sufficient to provide forthe desired combustion modification of flexible polyurethane foams prepared therefrom.
• the dispersion comprises the melamine in an amount of from 20 to 60, preferably at least 25, and more preferably at least 30, and preferably at most 55, more preferably at most 50, and most preferably at most 35 weight percent based on total weight of melamine and polyol including polymer solids.
• the melamine has a small particle size generally it will be present in a smaller amount than when having a larger particle size.
• the stability of the melamine dispersed in the continuous phase is provided for by the presence of an inorganic particulate solid (IPS) that has an average particle size of from 5 to 30 nanometers.
• the IPS has an average particle size of from 5 to 20, and more preferably from 7 to 14 nanometers.
• the IPS is present in an amount of from 0.2 to 5, preferably at least 0.25, more preferably at least 0.5, and preferably at most 3.0, more preferably at most 2.0 percent based on the total weight of melamine and polyol including polymer solids present. Greater amounts of the IPS generally providing for enhanced storage stability characteristics of the dispersion and ability to redisperse the melamine should any sedimentation occur.
• Suitable IPS substances for use in the present invention include hydrophilic substances compatible with processes for the preparation of polyurethane polymers such as silicates or especially silicic acids and particularly fumed silicic acids.
• exemplary of preferred silicic acid products for use in this present invention include substances designated as AEROSIL 200, AEROSIL 300 and AEROSIL 380 available from Degussa GmbH, Germany.
• a dispersing aid when preparing the dispersions of this invention a dispersing aid may be present.
• the dispersing aid advantageously is used in an amount of from 0.25 to 1.5, preferably from 0.5 to 1.0 percent based on total weight of melamine and continuous phase including polymer solids.
• Suitable dispersing aids include derivatives of fatty acids and particularly amine salts of electroneutral fatty acids.
• Exemplary of a commercially available and preferred dispersing aid suitable for use in this present invention is TEGODISPERS 705 available from Th. GoldschmidtAG and understood to be an amine salt of a fatty acid.
• the stable dispersion described hereinabove can be prepared by contacting and mixing the desired quantity of continuous phase, melamine and IPS and optional dispersing aid.
• the IPS and optional dispersing aid may be present in the continuous phase prior to the addition of the melamine, added during the addition of melamine or subsequent to the addition of the melamine.
• the continuous phase, IPS and optional dispersing aid are premixed and then in a subsequent step mixed with the melamine.
• the elevated temperature need not be greater than 60°C and preferably is from 30°C to 60°C, more preferably from 40°C to 55°C. Depending on the batch size of the preparation, components and their amounts, and mixing conditions employed, mixing times may vary from ten to five hours.
• This invention also relates to a polyurethane polymer obtained by contacting and intimately mixing under reaction conditions an organic isocyanate with an isocyanate-reac ve * composition that comprises the described stable dispersion.
• the isocyanate-reactive composition comprises the dispersion in a quantity sufficient to provide for an end melamine concentration within the polymer that provides for the desired modification of the combustion characteristics of the polymer.
• the melamine/polymer polyol dispersion will comprise at least 25, preferabl at least 35, and more preferably at least 45 percent by weight of the total isocyanate-reactive composition including dispersion present.
• the isocyanate-reactive composition may also contain other isocyanate-reactive compounds especially other polyols, including polyether polyols, polyester polyols, chain-extending agents, and same ordifferent polymer polyols optionally characterized by the absence of melamine dispersed therein.
• Suitable additional isocyanate- reactive compounds that may be present include polyether polyols having an average functionality of from 1.6, preferably from 1.8, more preferably from 1.9, up to 3.0; an average hydroxyl equivalent weight of from 500 to 5000, preferably from 1000 to 3000, and more preferably from 1500to 2500; and optionally a primary hydroxyl content of at least 30 and preferably at least 50 percent of its total hydroxyl content.
• VORANOL polyether polyol products designated by the trademark "VORANOL” and include VORANOL CP 4800 and VORANOL CP-6001 available from The Dow Chemical Company.
• the organic polyisocyanates useful in preparing the polyurethane polymer include those containing at least 2 and preferably from 2.0 to 3.0 isocyanate groups per molecule.
• Suitable isocyanates include aromatic polyisocyanates, aliphatic, cycloaliphaticand heterocyclic polyisocyanates used alone or in admixture.
• the preferred isocyanates used in the practice of this invention are aromatic polyisocyanates and include toluene diisocyanate, especially mixtures of the 2,4 and 2,6 isomers in weight ratios of 65:35 or 80:20; and polyisocyanate mixtures comprising 2,4'- or 4,4'-methylene diphenylisocyanate; or isocyanate- -term ⁇ nated prepolymers thereof.
• the isocyanate is present in an amount to provide from 0.85 to 1.25, preferably at least 0.95, more preferably at least 1.0 and most preferably at least 1.02, and preferably at most 1.15, and more preferably at most 1.05 isocyanate groups per isocyanate reactive hydrogen atom present including those of any water present.
• the blowing agent is present in an amount to provide the resulting polymer with an overall density of from 10 to 100, preferably from 15 to 80, and more preferably from 20 to 60 kg/m3.
• a preferred blowing agent for general use in the production of the polymer of this invention is water advantageously present in proportions of from 0.5 to 8, preferably from 1 to 6, and more preferably from 2 to 6 percent based on the total weight of the isocyanate-reactive composition.
• Non-reactive blowing agents can be used in conjunction with water or less preferably as a total replacement of water.
• blowing agents include certain halogen- and non- halogen-substituted aliphatic or cycloaliphatic hydrocarbons having boiling points ranging from -40°Cto + 100°C including methylene chloride, volatile fluorocarbons and chlorofluorocarbons, e.g. trichlorofluoromethane, dichlorodifluoromethane and 1-chloro-2- fluoroethane and low boiling hydrocarbons, e.g. n-propane, cyclopropane, butane, isobuta ⁇ e, pentane, hexane, cyclohexane and their mixtures.
• catalysts are present. Suitable catalysts are those known to those • skilled in the art of preparing polyurethane polymers and include tertiary amines and metallic compounds.
• Useful tertiary amines include N-alkylmorpholines, such as N-ethylmorpholine, N,N-dialkylcyclohexylamines where the alkyl groups are methyl, ethyl, propyl and butyl, trialkylamines such astriethylamine, tripropylamine, tributylamine and triamylamine, triethylenediamine, bis(2-dimethylaminoethyl) ether, N,N-dimethylaminoethyl- -N',N'-dimethylaminopropyl ether, and other tertiary amines well known in the art.
• N-alkylmorpholines such as N-ethylmorpholine, N,N-dialkylcyclohexylamines where the alkyl groups are methyl, ethyl, propyl and butyl
• trialkylamines such astriethylamine,
• UsefuB metal compounds include those of bismuth, lead, titanium, iron, antimony, uranium, cadmium, cobalt, aluminum, mercury, zinc, nickel, cerium, vanadium, copper, manganese, zirconium and tin. Tin compounds are particularly useful, examples including stannous octoate, (stannous 2-ethylhexoate) and dibutyltin dilaurate.
• the levels of catalyst used are conventional, typically ranging from 0.01 to 3 parts by weight per 100 parts of isocyanate-reactive composition.
• at least one surfactant and/or cell regulating agent is present when preparing the polyurethane.
• Suitable surfactants include non-silicone containing surfactants, such as poly(alkyleneoxides) and the diverse silicone surfactants, preferably those which are block copolymers of a polysiloxane and a polyoxyalkylene as described in U.S. Patent 3,629,308.
• exemplary of such surfactants are the products designated as DC- 193 and Q4-3667 available from Dow Corning and TEGOSTAB B41 13 and B8681 available from Th. Goldschmidt AG.
• the amount of surfactants advantageously employed is from 0.1 to 3, preferably from 0.2 to 1.5 percent by total weight of the isocyanate-reactive composition.
• TCEP tris(chloroethyl)phosphonate
• DMMP dimethoxymethyl phosphonate
• the polymers according to this invention can be prepared by any of the methods known in the art, including prepolymer and quasi-prepolymer methods though preferred are one-shot procedures. Typical of a suitable manufacturing procedure is that as disclosed in U-S. Patent 3,874,988. Other suitable manufacturing procedures are such as described in, for example, "Polyurethanes Handbook" by G ⁇ nter Oertel Hanser Publishes Kunststoff ISBN 0-02- 948920-2 (1985).
• the polyurethane polymer obtained according to this invention comprises the melamine in an amount sufficient to provide the polymer with the desired modification of the combustion characteristics of the polymer. Typically the polyurethane polymer contains melamine particles from 2 to 30 and more typically from 5 to 25 percent of total polymer weight including melamine.
• the polyurethane polymer will also contain the organic polymer solid and IPS in correspondingly loweramounts.
• the IPS typically being present in an amount of from 0.1 to 2.5, more typically from 0.2 to 1.5 percent of total polymer weight including melamine present.
• the organic polymer solid typically being present in an amount of from 2 to 25, and more typically from 2 to 15 percent of total polymer weight.
• the polyurethane polymers, particularly foams, prepared from the dispersion of this invention are useful in the preparation of articles such as upholstery materials, packing materials and insulation for sound or heat, and automotive applications such as, for example, head rests and steering wheels.
• Melamine A melamine average particle size 90 microns, supplied by DSM
• Melamine B melamine average particle size 10 microns, supplied by DSM
• Polyol B SAN copolymer polyol (15% solids), VORALUX" HN 202 supplied by The
• Thermolin 101 a halogen/phosphorus flame retardant additive supplied by Olin S.A.;
• a stable dispersion of melamine in a PHD polymer polyol is prepared, which in the absence of an inorganic particulate solid is also observed not to possess desirable stability characteristics.
• a similar lack of dispersion stability is also observed for melamine dispersed in a PIPA polymer polyol when an IPS is absent.
• Polyurethane foam is prepared from Dispersions 4 and 10.
• the formulation used to prepare the foam and the physical properties ofthe resulting foam is given in Table 3.
• Comparative Foam A is prepared from similar components but wherein the melamine is mixed directly in the isocyanate-reactive composition and used immediately in the preparation of a polyurethane foam. Processing and physical properties of the resulting foams are seen to be essentially equivalent with the exception of results form the F.R. testing. Comparative foam A is observed to have a significantly inferior F.R. performance compared to Foam 1.
• a further n advantage observed when preparing polyurethane foam with the stable dispersion of this invention by a continuous foaming process is the enhanced reproducibility/consistency ofthe F.R. performance ofthe foam.
• the concentration of melamine in the foam can vary depending on whether the foam sample considered is produced at an early or late stage ofthe continuous foaming process.
• the variance in C . melamine concentration can be observed through poor reproducibility of the F.R. performance observed for different samples ofthe foam.
• Non or poor stability of the dispersed melamine is considered to result in a non uniform distribution of melamine.

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• Chemical Kinetics & Catalysis (AREA)
• Medicinal Chemistry (AREA)
• Polymers & Plastics (AREA)
• Organic Chemistry (AREA)
• Dispersion Chemistry (AREA)
• Polyurethanes Or Polyureas (AREA)

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• 1992
  • 1992-09-30 CA CA002119570A patent/CA2119570A1/en not_active Abandoned
  • 1992-09-30 EP EP92921915A patent/EP0607312A1/de not_active Ceased
  • 1992-09-30 WO PCT/US1992/008367 patent/WO1993007193A1/en not_active Application Discontinuation

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