Fire resistant material

Abstract

The present invention relates to inorganic-organic hybrids (IOHs), methods for their preparation and their use as fire resistant materials or components of fire resistant materials. More specifically, the invention relates to polyamide fire resistant formulations containing IOHs which have application in the production of fire resistant articles or parts thereof for use in the transportation, building, construction and electrical or optical industries.

1 . An inorganic-organic hybrid (IOH) which comprises: 
 (i) an expandable or swellable layered inorganic component; and    (ii) an organic component including at least one ionic organic component and one or more neutral organic components which are intercalated between and/or associated with the layer(s) of the inorganic component,    the ionic or neutral organic components being capable of decomposing or subliming endothermically, and/or releasing volatiles with low combustibility on decomposition and/or inducing charring of organic species during thermal decomposition or combustion.    
   
   
       2 . An IOH according to  claim 1 , in which the inorganic component is rendered positively or negatively charged due to isomorphic substitution of elements within the layers.  
   
   
       3 . An IOH according to  claim 1 , in which the inorganic component is selected from a 1:1 layered silicate structure, a 2:1 layered silicate structure, a double hydroxide of the general formula Mg 6 Al 3.4 (OH) 18.8 (CO 3 ) 1.7 .H 2 O and a synthetically prepared layered material.  
   
   
       4 . An IOH according to  claim 1 , in which the inorganic compound is a naturally occurring or a synthetic analogue of a phyllosilicate.  
   
   
       5 . An IOH according to  claim 4 , in which the naturally occurring or synthetic analogue of a phyllosilicate is a smectite clay.  
   
   
       6 . An IOH according to  claim 5 , in which the smectite clay is selected from montmorillonite, nontronite, beidellite, volkonskoite, hectorite, bentonite, saponite, sauconite, magadiite, kenyaite, laponite, vermiculite, synthetic micromica and synthetic hectorite.  
   
   
       7 . An IOH according to  claim 5 , in which the naturally occurring phyllosilicate is selected from bentonite, montmorillonite and hectorite.  
   
   
       8 . An IOH according to  claim 4 , in which the phyllosilicate has a platelet thickness less than about 5 nanometers and an aspect ratio greater than about 10:1.  
   
   
       9 . An IOH according to  claim 8 , in which the aspect ratio is greater than about 50:1.  
   
   
       10 . An IOH according to  claim 8 , in which the aspect ratio is greater than about 100:1.  
   
   
       11 . An IOH according to  claim 1 , in which the inorganic component includes interlayer or exchangeable metal cations to balance the charge.  
   
   
       12 . An IOH according to  claim 11 , in which the metal cation is selected from an alkali metal and alkali earth metal.  
   
   
       13 . An IOH according to  claim 12 , in which the alkali or alkali earth metal is selected from Na + , K + , Mg 2+  and Ca 2+ .  
   
   
       14 . An IOH according to  claim 11 , in which the cation exchange capacity of the inorganic component is less than about 400 milli-equivalents per 100 grams.  
   
   
       15 . An IOH according to  claim 11 , in which the ionic organic component is exchanged with the exchangeable metal ions of the inorganic component.  
   
   
       16 . An IOH according to  claim 1 , in which the ionic species contains onium ion(s).  
   
   
       17 . An IOH according to  claim 16 , in which the ionic species containing onium ion(s) is an ammonium, phosphonium or sulfonium derivative of an aliphatic, aromatic or aryl-aliphatic amine, phosphine or sulfide.  
   
   
       18 . An IOH according to  claim 1 , in which the ionic or neutral organic component is a neutral or ionic derivative of a nitrogen based molecule.  
   
   
       19 . An IOH according to  claim 18 , in which the nitrogen based molecule is a triazine based species.  
   
   
       20 . An IOH according to  claim 19 , in which the triazine based species is selected from melamine, triphenyl melamine, melam (1,3,5-triazine-2,4,6-triamine-n-(4,6-diamino-1,3,5-triazine-yl)), melem ((-2,5,8-triamino-1,3,4,6,7,9,9b-heptaazaphenalene)), melon (poly{8-amino-1,3,4,6,7,9,9b-heptaazaphenalene-2,5diyl)imino}), bis and triaziridinyltriazine, trimethylsilyltriazine, melamine cyanurate, melamine phthalate, melamine phosphate, melamine phosphite, melamine phthalimide, dimelamine phosphate, phosphazines, low molecular weight polymers with triazine and phosphazine repeat units and isocyanuric acid and salts or derivatives thereof.  
   
   
       21 . An IOH according to  claim 20 , in which isocyanuric acid and salts or derivatives thereof are selected from isocyanuric acid, cyanuric acid, triethyl cyanurate, melamine cyanurate, trigylcidylcyanurate, triallyl isocyanurate, trichloroisocyanuric acid, 1,3,5-tris(2-hydroxyethyl)triazine-2,4,6-trione, hexamethylenentetramine.melam cyanurate, melem cyanurate and melon cyanurate.  
   
   
       22 . An IOH according to  claim 18 , in which the organic component is a derivative of phosphoric acid or boric acid.  
   
   
       23 . An IOH according to  claim 22 , in which the derivative of phosphoric acid or boric acid is selected from ammonia polyphosphate, melamine polyphosphate and melamine phosphate ammonium borate.  
   
   
       24 . An IOH according to  claim 1 , in which the ionic organic component is used in combination with other ionic compounds which are capable of improving compatibility and dispersion between the inorganic and organic components.  
   
   
       25 . An IOH according to  claim 24 , in which the other ionic compound is an amphiphilic molecule that incorporates a hydrophilic ionic group along with hydrophobic alkyl or aromatic moieties.  
   
   
       26 . An IOH according to  claim 1 , which further comprises one or more coupling reagents.  
   
   
       27 . An IOH according to  claim 26 , in which the coupling reagent is selected from an organically functionalised silane, zirconate and titanate.  
   
   
       28 . An IOH according to  claim 27 , in which the silane coupling reagent is tri-alkoxy, acetoxy or halosilanes functionalised with amino, epoxy, isocyanate, hydroxyl, thiol, mercapto and/or methacryl reactive moieties or modified to incorporate functional groups based on triazine derivatives, long chain alkyl, aromatic or alkylaromatic moieties.  
   
   
       29 . A method for the preparation of the IOH defined in  claim 1 , which comprises mixing components (i) and (ii) or constituents thereof in one or more steps.  
   
   
       30 . A method according to  claim 29 , in which mixing is achieved using melt, solution or powder processing.  
   
   
       31 . A method according to  claim 29 , in which the mixing is achieved using solution processing.  
   
   
       32 . A method for using the IOH defined in  claim 1  as a fire resistant material.  
   
   
       33 . A fire resistant formulation which comprises: 
 (i) the IOH defined in  claim 1;  and    (ii) one or more flame retardants.    
   
   
       34 . A formulation according to  claim 33 , in which the flame retardant is selected from phosphorus derivatives, nitrogen containing derivatives, molecules containing borate functional groups, molecules containing two or more alcohol groups, molecules which endothermically release non-combustible decomposition gases and expandable graphite.  
   
   
       35 . A formulation according to  claim 34 , in which the phosphorus derivatives are selected from melamine phosphate, dimelamine phosphate, melamine polyphosphate, ammonia phosphate, ammonia polyphosphate, pentaerythritol phosphate, melamine phosphite and triphenylphosphine.  
   
   
       36 . A formulation according to  claim 34 , in which the nitrogen containing derivatives are selected from melamine, melamine cyanurate, melamine phthalate, melamine phthalimide, melam, melem, melon, melam cyanurate, melem cyanurate, melon cyanurate, hexamethylene tetraamine, imidazole, adenine, guanine, cytosine and thymine.  
   
   
       37 . A formulation according to  claim 34 , in which the molecules containing borate functional groups are selected from ammonia borate and zinc borate.  
   
   
       38 . A formulation according to  claim 34 , in which the molecules containing two or more alcohol groups are selected from pentaerytliritol, polyethylene alcohol, polyglycols and carbohydrates.  
   
   
       39 . A formulation according to  claim 34 , in which the molecules which endothermically release non-combustible decomposition gases are selected from magnesium hydroxide and aluminum hydroxide.  
   
   
       40 . A method for the preparation of the fire resistant formulation defined in  claim 33 , which comprises mixing the following components or constituents thereof in one or more steps: 
 (i) an expandable or swellable layered inorganic component; and    (ii) an organic component including at least one ionic organic component and one or more neutral organic components which are intercalated between and/or associated with the layer(s) of the inorganic component,    the ionic or neutral organic components being capable of decomposing or subliming endothermically, and/or releasing volatiles with low combustibility on decomposition and/or inducing charring of organic species during thermal decomposition or combustion.    
   
   
       41 . A method according to  claim 40 , in which mixing is achieved using melt, solution or powder processing.  
   
   
       42 . A method according to  claim 40 , in which the mixing is achieved using melt processing in a twin screw extruder or batch mixer; or powder processing using a high shear powder mixer or milling procedures.  
   
   
       43 . A polyamide fire resistant formulation which comprises either: 
 (A) (i) the IOH defined in  claim 1;  and 
 (ii) a polyamide based matrix; or  
   (B) (i) a fire resistant formulation comprising the IOH defined in  claim 1  and one or more flame retardants; and 
 (ii) a polyamide based matrix.  
   
   
   
       44 . A formulation according to  claim 43 , in which the polyamide based matrix comprises generic groups with repeat units based on amides selected from Nylon4, Nylon6, Nylon7, Nylon 11, Nylon12, Nylon46, Nylon66, Nylon 68, Nylon610, Nylon612 and aromatic polyamides and co-polymers, blends or alloys thereof.  
   
   
       45 . A formulation according to  claim 43 , in which the polyamide based matrix is selected from Nylon12, Nylon6 and Nylon66 and co-polymers, alloys or blends thereof.  
   
   
       46 . A formulation according to  claim 43 , which further comprises one or more additives.  
   
   
       47 . A formulation according to  claim 46 , in which the additives are selected from polymeric stabilisers; lubricants; antioxidants; pigments, dyes or other additives to alter the materials optical properties or colour; conductive fillers or fibers; release agents; slip agents; plasticisers; antibacterial or fungal agents; and processing agents.  
   
   
       48 . A formulation according to  claim 47 , in which the polymeric stabiliser is a UV, light or thermal stabilizer.  
   
   
       49 . A formulation according to  claim 47 , in which the processing agents are selected from dispersing reagents, foaming or blowing agents, surfactants, waxes, coupling reagents, rheology modifiers, film forming reagents and free radical generating reagents.  
   
   
       50 . A formulation according to  claim 43 , in which the polyamide based matrix is Nylon12, Nylon6 and/or Nylon66; the IOH is montmorillonite or hectorite modified with melamine hydrochloride and/or melamine cyanurate hydrochloride and/or melamine and/or melamine cyanurate; and the flame retardant is melamine cyanurate and/or magnesium hydroxide; and the additive is a processing agent and/or a polymeric stabiliser.  
   
   
       51 . A formulation according to  claim 46 , in which the polyamide based matrix is present in an amount of about 45 to about 95% w/w, the IOH is present in an amount less than about 25% w/w and the flame retardant and/or additives are present in an amount less than about 30% w/w.  
   
   
       52 . A formulation according to  claim 46 , in which the polyamide based matrix is present in an amount greater than about 75% w/w, the IOH is present in an amount less than about 3% w/w, the melamine cyanurate flame retardant is present in an amount of about 11 to about 15% w/w and additives are present in an amount of about less than about 4% w/w.  
   
   
       53 . A formulation according to  claim 46 , in which the polyamide based matrix is present in an amount greater than about 75% w/w, the IOH is present in an amount less than about 3% w/w, the melamine cyanurate flame retardant is present in an amount of about 11 and about 15% w/w, magnesium hydroxide flame retardant present in an amount of about 1 and about 5% w/w and additives are present in an amount less than about 4% w/w.  
   
   
       54 . A method for the preparation of the polyamide fire resistant formulation defined in  claim 43 , which comprises dispersing an inorganic-organic hybrid (IOH) comprising: 
 (i) an expandable or swellable layered inorganic components and    (ii) an organic component including at least one ionic organic component and one or more neutral organic components which are intercalated between and/or associated with the layer(s) of the inorganic component, the ionic or neutral organic components being capable of decomposing or subliming endothermically, and/or releasing volatiles with low combustibility on decomposition and/or inducing charring of organic species during thermal decomposition or combustion    and optionally including one or more fire retardants into the polyamide based matrix in one or more steps.    
   
   
       55 . A method according to  claim 54 , in which at least some of the components are ground prior to mixing.  
   
   
       56 . A method according to  claim 55 , in which the components are ground to a particle size less than about 200 microns.  
   
   
       57 . A method according to  claim 55 , in which dispersion is achieved using melt, solution or powder processing.  
   
   
       58 . A method according to  claim 55 , in which the dispersion is achieved using melt processing in a single or twin screw extruder, batch mixer or continuous compounder.  
   
   
       59 . A method according to  claim 58 , in which the melt processing is conducted in a twin screw extruder.  
   
   
       60 . A method according to  claim 54 , in which the dispersion occurs at a sufficient shear rate, shear stress and residence time to disperse the IOH at least partially on a nanometer scale.  
   
   
       61 . A fire resistant article or parts thereof which is composed wholly or partly of the IOH as defined in  claim 1 .  
   
   
       62 . A fire resistant article or parts thereof as defined in  claim 61 , which is used in transport, building, construction, electrical or optical applications.  
   
   
       63 . A fire resistant article or parts thereof as defined in  claim 62 , in which the transport application is air, automotive, aerospace or nautical.  
   
   
       64 . A fire resistant article or parts thereof as defined in  claim 61 , which is a hollow article or sheet.  
   
   
       65 . A fire resistant article or parts thereof as defined in  claim 61  which is selected from pipes, ducts, fabric, carpet, cables, wires, fibres, Environmental control systems, stowage bin hinge covers, cable trays, ECS duct spuds, latches, brackets, passenger surface units and thermoplastic laminate sheet.  
   
   
       66 . A fire resistant hollow article or parts thereof which is composed wholly or partly of the fire resistant formulation defined in  claim 52  and manufactured by rotational moulding or extrusion.  
   
   
       67 . A fire resistant fibre, fabric, carpet or parts thereof which is composed wholly or partly of the fire resistant formulation defined in  claim 52  and manufactured by melt spinning or extrusion.  
   
   
       68 . A fire resistant article or parts thereof which is composed wholly or partly of the formulation defined in  claim 52  and manufactured by sintering.  
   
   
       69 . A fire resistant article or parts thereof which is composed wholly or partly of the fire resistant formulation defined in  claim 52  and manufactured by injection or compression moulding.  
   
   
       70 . (canceled)  
   
   
       71 . (canceled)