Coupling of reinforcing fibres to resins in curable composites

Abstract

A method for preparing a moulded composite comprises milling reinforcing fibres to a mean fibre length of less than 5 mm, treating the milled fibres with a coupling agent and suspending the dried fibres in a liquid resin which reacts with the coupling agent on the fibres. Preferred fibres include glass fibres and milled mica coated with calcined iron oxide. Preferred coupling agents are organosilanes and metal acrylates e.g. zinc diacrylate. Composites formed by the above method exhibit improved impact resistance, tensile strength and flexural strength.

1 . A reinforcing fibre having a surface with substantially no sizing agent thereon, wherein the surface of the fibre is substantially coated with a coupling agent for coupling said fibre with a resin when cured.  
   
   
       2 . A reinforcing fibre as claimed in  claim 1 , which is substantially inorganic and which is suitable for use with a resin which is substantially organic, the coupling agent comprising a plurality of molecules each having a first end adapted to bond to the fibre and a second end which is adapted to bond to the resin.  
   
   
       3 . A reinforcing fibre as claimed in  claim 1  or  claim 2 , wherein said coupling agent has been selected from the group consisting of a polymerisable coupling agent and a coupling agent which has been at least partially polymerised before application thereof to the fibre.  
   
   
       4 . A reinforcing fibre as claimed in  claim 3 , wherein the coupling agent is a non-polymerised polymerisable coupling agent.  
   
   
       5 . A reinforcing fibre as claimed in  claim 3  or  claim 4 , wherein said coupling agent has been at least partially polymerised after application thereof to the fibre.  
   
   
       6 . A reinforcing fibre as claimed in  claim 5 , wherein said coupling agent has been at least partially polymerised in the presence of additional polymerisable coupling agent.  
   
   
       7 . A reinforcing fibre as claimed in any one of  claims 1  to  6 , wherein at least one of the fibre, the resin and the coupling agent have been selected so as to yield a composite of high impact resistance.  
   
   
       8 . A reinforcing fibre as claimed in any one of  claims 1  to  7 , wherein at least one of the fibre, the resin and the coupling agent have been selected so as to yield a composite of high tensile strength.  
   
   
       9 . A reinforcing fibre as claimed in any one of  claims 1  to  8 , wherein at least one of the fibre, the resin and the coupling agent have been selected so as to yield a composite of high flexural strength.  
   
   
       10 . A reinforcing fibre as claimed in any one of  claims 1  to  9 , wherein the coupling agent has been selected from the group consisting of a silane, an organic metal ligand and combinations thereof.  
   
   
       11 . A reinforcing fibre as claimed in  claim 10 , wherein the coupling agent is a titanate, a zirconate or a combination thereof.  
   
   
       12 . A reinforcing fibre, wherein said fibre has a surface which is substantially coated with a coupling agent for coupling said fibre with a substantially organic resin wren cured, said coupling agent being at least partially polymerised.  
   
   
       13 . A reinforcing fibre as claimed in  claim 12 , wherein the coupling agent has been selected from the group consisting of a polymerised or partially polymerised silane, a polymerised or partially polymerised organic metal ligand and combinations thereof.  
   
   
       14 . A reinforcing fibre as claimed in any one of  claims 1  to  13 , wherein the surface of the fibre has been pre-treated with a metal oxide before application of the coupling agent thereto.  
   
   
       15 . A reinforcing fibre as claimed in  claim 14 , wherein the metal oxide is selected from iron (III) oxide, iron (II) oxide, titanium dioxide, tungsten oxide, hafnium dioxide, nickel oxide, cobalt oxide, manganese dioxide, chromium trioxide, vanadium pentoxide, zinc oxide, molybdenum trioxide, tin dioxide, indium trioxide, niobium pentoxide, tantalum pentoxide and zirconium dioxide.  
   
   
       16 . A process for making a reinforcing fibre suitable for use in reinforcing a composite made of the fibre and a resin, said process including the step of substantially removing any sizing agent previously applied to the surface of the reinforcing fibre.  
   
   
       17 . A process for making a reinforcing fibre as claimed in  claim 16 , said process including the additional step of substantially coating the surface of the fibre with a coupling agent for coupling said fibre to said resin  
   
   
       18 . A process for making a reinforcing fibre as claimed in  claim 16  or  claim 17 , wherein the fibre is substantially inorganic and the resin is substantially organic, and the coupling agent comprises a plurality of molecules each having a first end which is adapted to bond to the fibre and a second end which is adapted to bond to the resin.  
   
   
       19 . A process for making a reinforcing fibre as claimed in  claim 18 , wherein said coupling agent has been selected from the group consisting of a polymerisable coupling agent and a coupling agent which is at least partially polimerised.  
   
   
       20 . A process for making a reinforcing fibre as claimed in  claim 19 , wherein the coupling agent is a polymerisable coupling agent that has been allowed to at least partially polymerise in the presence of additional coupling agent.  
   
   
       21 . A process for making a reinforcing fibre as claimed in  claim 20 , wherein the coupling agent has been selected from the group consisting of an unpolymerised or partially polimerised silane, an unpolymerised or partially polimerised organic metal ligand and combinations thereof.  
   
   
       22 . A process for making a reinforcing fibre as claimed in  claim 21 , wherein the organic metal ligand is a titanate, a zirconate or a combination thereof.  
   
   
       24 . A process for making a reinforcing fibre as claimed in  16  to  22 , wherein the surface of the fibre has been pre-treated with a metal oxide after removal of the sizing agent but before application of the coupling agent thereto.  
   
   
       25 . A process for making a reinforcing fibre as claimed  claim 24 , wherein the metal oxide is selected from iron (III) oxide, iron (II) oxide, titanium dioxide, tungsten oxide, hafnium dioxide, nickel oxide, cobalt oxide, manganese dioxide, chromium trioxide, vanadium pentoxide, zinc oxide, molybdenum trioxide, tin dioxide, indium trioxide, niobium pentoxide, tantalum pentoxide and zirconium dioxide.  
   
   
       26 . A reinforcing fibre for a curable resin made by the process according to any one of  claims 16  to  25 ,  
   
   
       27 . A cured composite comprising a cured resin incorporating a plurality of reinforcing fibres, at least a portion of said reinforcing fibres having a surface from which sizing agent has been substantially removed.  
   
   
       28 . A cured composite as claimed in  claim 27 , wherein at least a portion of said reinforcing fibres has a surface which is substantially coated with a coupling agent for coupling said fibre with said resin.  
   
   
       29 . A cured composite as claimed in  claim 28 , wherein said coupling agent has been selected from the group consisting of a polymerisable coupling agent and a coupling agent which has been at least partially polimerised.  
   
   
       30 . A cured composite as claimed in  claim 28  or  claim 29 , wherein the fibre is substantially inorganic and the resin is substantially organic, and the coupling agent comprises a plurality of molecules each having a first end adapted to bond to the fibre and a second end which is adapted to bond to the resin.  
   
   
       31 . A cured composite as claimed in any one of claims  29  or  30 , wherein the coupling agent is a coupling agent which has been at least partially polymerised.  
   
   
       32 . A cured composite as claimed in any one of claims  29  or  30 , wherein the coupling agent is a polymerisable coupling agent.  
   
   
       33 . A cured composite as claimed in  claim 32 , wherein the coupling agent has been selected from the group consisting of a silane, an organic metal ligand and combinations thereof.  
   
   
       34 . A cured composite as claimed in  claim 33 , wherein the coupling agent is a titanate, a zirconate or a combination thereof.  
   
   
       35 . A cured composite as claimed in any one of  claims 32  to  34 , wherein the coupling agent was at least partially polymerised after application thereof to the reinforcing fibre, but before polymerisation of the resin.  
   
   
       36 . A cured composite as claimed in  claim 31 , wherein the coupling agent has been selected from the group consisting of a polymerised or partially polimerised silane, a polymerised or partially polimerised organic metal ligand and combinations thereof.  
   
   
       37 . A cured composite as claimed in any one of  claims 27  to  36 , wherein the surface of the fibre has been pre-treated with a metal oxide before application of the coupling agent thereto.  
   
   
       38 . A reinforcing fibre as claimed in  claim 37 , wherein the metal oxide is selected from iron (III) oxide, iron (I) oxide, titanium dioxide, tungsten oxide, hafnium dioxide, nickel oxide, cobalt oxide, manganese dioxide, chromium trioxide, vanadium pentoxide, zinc oxide, molybdenum trioxide, tin dioxide, indium trioxide, niobium pentoxide, tantalum pentoxide and zirconium dioxide.  
   
   
       39 . A curable composite comprising a curable resin incorporating a plurality of reinforcing fibres, at least a portion of said reinforcing fibres having a surface which is substantially free of sizing agent.  
   
   
       40 . A curable composite as claimed in  claim 39 , in which at least a portion of said fibres are substantially coated with a coupling agent for coupling said fibres with the resin when cured.  
   
   
       41  A curable composite as claimed in  claim 40 , wherein said coupling agent has been selected from the group consisting of a polymerisable coupling agent and a coupling agent which is at least partially polymerised.  
   
   
       42 . A curable composite as claimed in  claim 40  or  claim 41 , wherein the fibres are substantially inorganic and the resin is substantially organic, and the coupling agent comprises a plurality of molecules each having a first end adapted to bond to the fibres and a second end which is adapted to bond to the resin.  
   
   
       43 . A curable composite as claimed in  claim 41  or  claim 42 , wherein the coupling agent is at least partially polimerised before application thereof to the reinforcing fibres.  
   
   
       44 . A curable composite as claimed in  claim 41  or  claim 42 , wherein the coupling agent has been polymerised, at least partially, after application thereof to the reinforcing fibres.  
   
   
       45 . A curable composite as claimed in any one of  claims 40  to  44 , wherein the coupling agent has been selected from the group consisting of a silane, an organic metal ligand and combinations thereof.  
   
   
       46 . A curable composite as claimed in  claim 45 , wherein the coupling agent is a titanate, a zirconate or a combination thereof.  
   
   
       47 . A curable composite as claimed in any one of  claims 40  to  46 , wherein the surface of the fibre has been pre-treated with a metal oxide before application of the coupling agent thereto.  
   
   
       48 . A curable composite as claimed in  claim 47 , wherein the metal oxide is selected from iron (III) oxide, iron (II) oxide, titanium dioxide, tungsten oxide, hafnium dioxide, nickel oxide, cobalt oxide, manganese dioxide, chromium trioxide, vanadium pentoxide, zinc oxide, molybdenum trioxide, tin dioxide, indium trioxide, niobium pentoxide, tantalum pentoxide and zirconium dioxide.  
   
   
       49 . A process for making a cured composite including the steps of: 
 preparing a curable composite by combining a curable resin and a plurality of reinforcing fibres, at least a portion of said reinforcing fibres having a surface from which substantially all sizing agent has been removed; and    curing said curable composite.    
   
   
       50 . A process for making a cured composite as claimed in  claim 49 , wherein at least a portion of the fibres have a surface which is substantially coated with a coupling agent fox coupling said fibre with the resin when cured.  
   
   
       51 . A process for making a cured composite as claimed in  claim 49  or  claim 50 , wherein said coupling agent is selected from the group consisting of a polymerisable coupling agent and a polymerised coupling agent.  
   
   
       52 . A process for making a cured composite as claimed in  claim 51 , wherein said coupling agent is a polymerisable coupling agent.  
   
   
       53 . A process for making a cured composite as claimed in any one of claims  50  to  52 , wherein the fibres are substantially inorganic and the resin is substantially organic, and the coupling agent comprises a plurality of molecules each having a first end adapted to bond to the fibres and a second end which is adapted to bond to the resin.  
   
   
       54 . A process for making a cured composite as claimed in any one of  claims 50  to  53 , wherein the coupling agent is at least partially polimerised before application thereof to the reinforcing fibres.  
   
   
       55 . A process for making a cured composite as claimed in any one of  claims 50  to  53 , wherein the coupling agent has been polymerised, at least partially, after application thereof to the reinforcing fibres.  
   
   
       56 . A process for making a cured composite as claimed in any one of  claims 50  to  55 , wherein the coupling agent has been selected from the group consisting of a silane, an organic metal ligand and combinations thereof.  
   
   
       57 . A process for making a cured composite as claimed in  claim 56 , wherein the coupling agent is a titanate, a zirconate or a combination thereof.  
   
   
       58 . A process for making a cured composite as claimed in any one of  claims 50  to  57 , wherein the surface of the fibre has been pre-treated with a metal oxide before application of the coupling agent thereto.  
   
   
       59 . A process for making a cured composite as claimed in  claim 58 , wherein the metal oxide is selected from iron (III) oxide, iron (II) oxide, titanium dioxide, tungsten oxide, hafnium dioxide, nickel oxide, cobalt oxide, manganese dioxide, chromium trioxide, vanadium pentoxide, zinc oxide, molybdenum trioxide, tin dioxide, indium trioxide, niobium pentoxide, tantalum pentoxide and zirconium dioxide.  
   
   
       60  A method of applying a composite to a surface, said method comprising: 
 preparing a curable composite by combining a curable resin and a plurality of reinforcing fibres at least a portion of said reinforcing fibres having a surface from which substantially all sizing agent has been removed;    applying the curable composite to the surface; and    curing said curable composite.    
   
   
       61 . A method of applying a composite to a surface as claimed in  claim 60 , in which at least a portion of the reinforcing fibres has a surface which is substantially coated with a coupling agent before the composite is prepared.  
   
   
       62 . A method of applying a composite to a surface as claimed in  claim 61 , wherein said coupling agent is selected from the group consisting of a polymerisable coupling agent and a polymerised coupling agent.  
   
   
       63 . A method of applying a composite to a surface as claimed in  claim 61  or  62 , wherein the fibres are substantially inorganic and the resin is substantially organic, and the coupling agent comprises a plurality of molecules each having a first end adapted to bond to the fibres and a second end which is adapted to bond to the resin.  
   
   
       64 . A method of applying a composite to a surface as claimed in any one of  claims 61  to  63 , wherein the coupling agent is at least partially polimerised before application thereof to the reinforcing fibres.  
   
   
       65 . A method of applying a composite to a surface as claimed in any one of  claims 61  to  63 , wherein the coupling agent has been polymerised, at least partially, after application thereof to the reinforcing fibres.  
   
   
       66 . A method of applying a composite to a surface as claimed in any one of  claims 61  to  65 , wherein the coupling agent has been selected from the group consisting of a silane, an organic metal ligand and combinations thereof.  
   
   
       67 . A method of applying a composite to a ice as claimed in  claim 66 , wherein the coupling agent is a titanate, a zirconate or a combination thereof.  
   
   
       68 . A method of applying a composite to a surface as claimed in any one of  claims 60  to  67 , wherein the surface of the fibre has been pre-treated with a metal oxide before application of the coupling agent thereto.  
   
   
       69 . A method of applying a composite to a surface as claimed in  claim 68 , wherein the metal oxide is selected from iron (III) oxide, iron (II) oxide, titanium dioxide, tungsten oxide, hafnium dioxide, nickel oxide, cobalt oxide, manganese dioxide, chromium trioxide, vanadium pentoxide, zinc oxide, molybdenum trioxide, tin dioxide, indium trioxide, niobium pentoxide, tantalum pentoxide and zirconium dioxide.  
   
   
       70 . A method of applying a composite to a surface as claimed in any one of  claims 60  to  69 , wherein the step of applying the curable composite to the surface is selected from painting, pumping, brushing, wiping, streaking, pouring, rolling, spreading or other suitable applying methods used in fibreglass fabrication.  
   
   
       71 . A method of applying a composite to a surface as claimed in any one of  claims 60  to  70 , wherein the fibres have a mean length of less than about 4 mm and the composite is applied to the surface by spraying.  
   
   
       72 . A method of applying a composite to a surface as claimed in  claim 71 , wherein the fibres have a mean length of about 3 mm.  
   
   
       73 . A method of applying a composite to a surface as claimed in  claim 71 , wherein the fibres have a maximum mean length of about 3 mm.  
   
   
       74 . A cured composite produced by the process according to any one of  claims 49  to  59 .  
   
   
       75 . A cured composite as claimed in  claim 75 , wherein the fibres have a maximum mean length of less than about 4 mm.  
   
   
       76 . A cured composite as claimed in  claim 75 , wherein the fibres have a mean length of less than about 3 mm.  
   
   
       77 . A cured composite as claimed in  claim 76 , wherein the fibres have a maximum mean length of under 1 mm.  
   
   
       78 . A method of moulding a composite, said method comprising: 
 preparing a curable composite by combining a curable resin and a plurality of reinforcing fibres, at least a portion of said fibres having a surface from which substantially all sizing agent has been removed;    locating the curable composite in a mould; and    curing said curable composite in the mould.    
   
   
       79 . A method of moulding a composite as claimed in  claim 78 , wherein at least a portion of said reinforcing fibres has a surface which has been coated with a coupling agent.  
   
   
       80 . A method of moulding a composite as claimed in  claim 79 , wherein the coupling agent has been selected from the group consisting of a polymerisable coupling agent and a polymerised coupling agent.  
   
   
       81 . A method of moulding a composite as claimed in  claim 79  or  claim 80 , wherein the fibres are substantially inorganic and the resin is substantially organic, and the coupling agent comprises a plurality of molecules each having a first end adapted to bond to the fibres and a second end which is adapted to bond to the resin.  
   
   
       82 . A method of moulding a composite as claimed in any one of  claims 79  to  81 , wherein the coupling agent is at least partially polimerised before application thereof to the reinforcing fibres.  
   
   
       83 . A method of moulding a composite as claimed in any one of  claims 79  to  81 , wherein the coupling agent has been polymerised, at least partially, after application thereof to the reinforcing fibres.  
   
   
       84 . A method of moulding a composite as claimed in any one of  claims 79  to  83 , wherein the coupling agent has been selected from the group consisting of a silane, an organic metal ligand and combinations thereof.  
   
   
       85 . A method of moulding a composite as claimed in  claim 84 , wherein the coupling agent is a titanate, a zirconate or a combination thereof.  
   
   
       86 . A method of moulding a composite as claimed in any one of  claims 78  to  85 , wherein the surface of the fibre has been pre-treated with a metal oxide before application of the coupling agent thereto.  
   
   
       87 . A method of moulding a composite as claimed in  claim 86 , wherein the metal oxide is selected from iron (III) oxide, iron (II) oxide, titanium dioxide, tungsten oxide, hafnium dioxide, nickel oxide, cobalt oxide, manganese dioxide, chromium trioxide, vanadium pentoxide, zinc oxide, molybdenum trioxide, tin dioxide, indium trioxide, niobium pentoxide, tantalum pentoxide and zirconium dioxide.  
   
   
       88 . A method of moulding a composite as claimed in any one of  claims 78  to  87 , wherein the fibres have a mean length of less than about 4 mm and the composite is applied to the surface by spraying.  
   
   
       89 . A method of moulding a composite as claimed in  claim 88 , wherein the fibres have a mean length of about 3 mm.  
   
   
       90 . A method of moulding a composite as claimed in  claim 89 , wherein the fibres have a maximum mean length of about 3 mm.  
   
   
       91 . A method of moulding a composite as claimed in any one of  claims 78  to  90 , wherein the step of locating the curable composite in the mould comprises pumping it, pouring it or otherwise placing it in the mould.  
   
   
       92 . A method of moulding a composite as claimed in  claim 91 , wherein the moulding process involves injection moulding and the step of locating the curable composite in the mould comprises injecting the curable composite into the mould.  
   
   
       93 . A method of moulding a composite as claimed in any one of  claims 78  to  92 , wherein the composite comprises an organic thixotrope.  
   
   
       94 . A method of moulding a composite as claimed in  claim 93 , wherein the organic thixotrope is selected from an amide and a glyceryl stearate.  
   
   
       95 . A method of moulding a composite as claimed in any one of  claims 78  to  94 , wherein the resin is selected from Eterset 2504 PT orthophthalic ethylene glycol fumaric acid resin, Eterset 2597 PT orthophthalic ethylene glycol fumaric acid resin, NAN YAR LAI 11 orthophthalic ethylene glycol fumaric acid resin and combinations thereof.  
   
   
       96 . A method of moulding a composite as claimed in any one of  claims 78  to  95 , wherein the fibre material is selected from milled glass fibre, an aramid fibre, a Wollastonite fibre, a nylon fibre, a calcined mica, a surface treated mica and combinations thereof.  
   
   
       97 . A method of moulding a composite as claimed in any one of  claims 78  to  96 , wherein the reinforcing fibre material is selected from the group consisting of surface treated mineral fibres such as Wollastonite, and ceramic fibres such as glass fibres, surface treated synthetic fibres, surface treated aramid fibres, mylar fibre&, nylon fibres, linear polyethylenes, linear polypropylenes, polyesters and carbon fibres.  
   
   
       98 . A method of moulding a composite as claimed in any one of  claims 78  to  97 , wherein the composite comprises a filler selected from Zenospheres, PVC powder, treated organo clays and combinations thereof.  
   
   
       99 . A method of moulding a composite as claimed in any one of  claims 78  to  98 , wherein the coupling agent is selected from a silane having an acrylic functional group, a silane having a vinyl functional group, a silane having a styrene functional group, zinc diacrylate, and combinations thereof.  
   
   
       100 . A method of moulding a composite as claimed in any one of  claims 78  to  99 , wherein the coupling agent is allowed to partially polymerise in aqueous solution prior to coupling thereof to the surface of the fibre and further polymerisation thereon.  
   
   
       101 . A method of moulding a composite as claimed in  claim 100 , wherein the pH of the aqueous solution is raised to more than 7.  
   
   
       102 . A method of moulding a composite as claimed in  claim 101 , wherein the resin has an elongation at break of greater than 6%.  
   
   
       103 . A method of moulding a composite as claimed in  claim 102 , wherein the resin has an elongation at break of greater than 10%.  
   
   
       104 . A method of moulding a composite as claimed in  claim 102  or  claim 103 , wherein the resin is selected from the group consisting of epoxy vinyl ester resins, tough vinyl functional urethane resins, tough vinyl functional acrylic resins, and non plasticised flexible polyester resins.  
   
   
       105 . A method of moulding a composite as claimed in any one of  claims 78  to  104 , wherein the composite comprises from 0% to 50% by weight of reinforcing fibres.  
   
   
       106 . A product including a reinforcing fibre, a process for making a reinforcing fibre, a process for making a plurality of reinforcing fibres, a reinforcing fibre for a curable resin made by the process of the invention, a cured composite, a curable composite, a process for making a curable composite, a method of applying a composite to a surface and a method of moulding a composite. The uniqueness of this invention has to do with the manufacture and the nature of the fibre reinforcement, the nature of the resins used, the way in which the fibres are mixed into the resin and processes for applying the composite to a mould. The composite formed as a result of adding the short fibre reinforcement improves the impact resistance, the tensile strength flexural strength of the cured composite, substantially simplifies the moulding process, increasing productivity and reducing or eliminating VOCs in the fabrication shop.  
   
   
       107 . A product according to  claim 106  which is able to be sprayed onto a mould or injected into a mould.  
   
   
       108 . A product according to  claim 106  which when sprayed onto an open mould does not require mechanical consolidation or when injected into a closed mould does not require any additional fibre reinforcement.  
   
   
       109 . A product according to  claim 106  which when sprayed onto an open mould does not require mechanical consolidation to optimise the properties of the composite.  
   
   
       110 . A method for preparing a product according to  claim 106  in which the reinforcing fibre is milled so that the mean fibre length is less than 5 mm. These fibres are te treated with a coupling agent, dissolved m a suitable solvent. The fibres are agitated in suspension in the coupling agent solution for a period of hours so that the entire surface of the fibres are coated in the coupling agent. The fibres are then filtered and dried. They are then sieved to break up agglomerates. The dried sieved fibres are then added to a liquid resin so that all the fibres are wetted individually, without incorporating air. The liquid resin is formulated so that it can react chemically with the coupling agent on the fibres.  
     The product is then catalysed, applied to a mould and allowed to cure.  
   
   
       111 . A method according to  claim 110  in which the reinforcing fibres are glass fibres, which are free of all surface pre treatment. These fibres are preferably milled so that they have a mean fibre length of approximately 3 mm with less than 1% fibres greater than 4 mm. An organo functional silane is then dissolved in water at pH of 3 and at a concentration of less than 1%. The preferred organo functional silanes are hose that contain a carbon double bond in their structure. The fibres are then added to the solution and agitated in the suspension for a period of hours so that all the available surface of the fibre is coated with the silane. Optionally the pH can be raised after this period to between pH 7 and pH 10 so that the remaining silane molecules in solution will react with the bound silanes to produce silanol oligomers. The fibres are then on the surface of the fibres, filtered from solution and dried. They are then sieved to break up agglomerates and suspended in suitable liquid resins such as unsaturated polyester resins, vinyl ester resins, acrylic resins, vinyl functional resins and combinations. The liquid resin is formulated so that it can react chemically with the coupling agent on the fibres.  
     The product is then applied to a mould and allowed to cure.  
   
   
       112 . A process made in accordance with  claim 111  except the fibre is milled mica which has been coated with calcined iron oxide prior to the application of silane coupling agents.  
   
   
       113 . A process made in accordance with  claim 110  where the fibres are synthetic fibres such as nylons, aramid fibres, PET fibres, polyester fibres surface treated linear polyethylene fibres. The coupling agent in these cases is a metal acrylate capable of forming chemical bonds to the surface of the fibres. An example is zinc diacrylate.  
   
   
       114 . A process made in accordance with  claim 106 ,  107 ,  108 ,  109 ,  110 ,  111  where the polymerisable resin is a resin with an elongation at break greater than 10%. These are the preferred resins because they produce products with superior physical properties.