Coated glass fibre mesh fabric with reduced gross heat of combustion

Abstract

The invention is drawn to a glass fiber mesh fabric coated with an organic polymer coating having a reduced gross heat of combustion (less than 3.0 MJ/kg), said polymer coating comprising (i) from 60 wt % to 99.9 wt % of poly(vinylidene chloride) (PVDC) or a copolymer thereof; and (ii) from 0.1 wt % to 40 wt % of a formaldehyde-based resin selected from melamine-formaldehyde resins, phenol-formaldehyde resins, urea-formaldehyde resins or a combination thereof. The invention also provides a method for producing such a coated glass fiber mesh fabric.

1 . A glass fiber mesh fabric coated with an organic polymer coating, wherein the organic polymer coating comprises: (i) from 60 wt % to 99.9 wt % of a poly(vinylidene chloride) (PVDC) or a copolymer thereof; and
 (ii) from 0.1 wt % to 40 wt % of a formaldehyde-based resin selected from the group consisting of a melamine-formaldehyde resin, a phenol-formaldehyde resin, a urea-formaldehyde resin and a combination thereof.   
     
     
         2 . The coated glass fiber mesh fabric according to  claim 1 , comprising from 6 wt % to 20 wt % of the organic polymer coating, measured as loss on ignition (LOI), relative to a total weight of the coated glass fiber mesh. 
     
     
         3 . The coated glass fiber mesh fabric according to  claim 1 , wherein the organic polymer coating comprises from 0.1 to 10 wt % of the melamine-formaldehyde resin or the phenol-formaldehyde resin or the urea-formaldehyde resin or a combination thereof. 
     
     
         4 . The coated glass fiber mesh fabric according to  claim 1 , wherein the organic polymer coating comprises a poly(vinylidene chloride) copolymer comprising from 75 to 98 wt % of vinylidene chloride monomer units and from 2 to 25 wt % of at least one comonomer selected from the group consisting of methyl acrylate, ethyl acrylate, butyl acrylate, methyl methacrylate, acrylonitrile, methacrylonitrile, an unsaturated carboxylic acid and vinyl chloride. 
     
     
         5 . The coated glass fiber mesh fabric according to  claim 1 , having a gross heat of combustion (PCS) of less than 3.5 MJ/kg (according to EN ISO 1716:2010). 
     
     
         6 . The coated glass fiber mesh fabric according to  claim 1 , wherein the organic polymer coating further comprises from 0.1 to 40 wt % of an organic polymer having a T g  lower than 40° C. 
     
     
         7 . The coated glass fiber mesh fabric according to  claim 6 , wherein the organic polymer having a T g  lower than 40° C. is selected from the group consisting of a polyacrylates, a polymethacrylate, a styrene-butadiene copolymer, a styrene-acrylate copolymer, a poly(vinyl acetate) and a poly(ethylene vinylacetate) copolymer. 
     
     
         8 . A method for producing the coated glass fiber mesh of  claim 1 , the method comprising:
 (a) impregnating a woven or knitted uncoated glass fiber mesh fabric with an aqueous coating composition comprising, with respect to total solids content,
 (i) from 60 wt % to 99.9 wt % of the poly(vinylidene chloride) (PVDC) or the copolymer thereof, and 
 (ii) from 0.1 wt % to 40 wt % of at least a second polymer selected from the group consisting of a melamine-formaldehyde resin, a phenol-formaldehyde resin, a urea formaldehyde resin and a combination thereof; and 
   (b) drying the impregnated glass fiber mesh fabric by heating at a temperature between about 100° C. and 280° C. for a period of time between about 5 seconds to 5 minutes.   
     
     
         9 . The method according to  claim 8 , wherein the poly(vinylidene chloride) or the copolymer thereof is an aqueous latex composition having a solids content between 30 and 70 wt %. 
     
     
         10 . The method according to  claim 8 , wherein the melamine-formaldehyde resin, the phenol-formaldehyde resin or the urea-formaldehyde resin is added as a non-cured aqueous solution of an oligomeric resin. 
     
     
         11 . The method according to  claim 8 , wherein the uncoated glass fiber mesh fabric has a weight of 30 to 500 g/m 2 .