Extended curable compositions for use as binders

Abstract

The present invention provides low-cost formaldehyde-free curable aqueous compositions comprising 100 weight parts of one or more than one binder chosen from (i) mixtures of one or more than one polycarboxylic acid or polymeric polyacid and one or more than one polyol compound comprising at least two hydroxyl or epoxy groups, (ii) copolymers or copolymeric polyacids bearing carboxylic acid groups or anhydride groups and hydroxyl groups, and (iii) mixtures thereof, and 10 to 40 weight parts of one or more than one extender having an average particle size ranging from 0.5 μm or more and as high as 45 μm or less, preferably chosen from microcrystalline silica, diatomaceous silica, kaolin, bentonite, and anhydrous aluminosilicate clay delaminated. In the inventive binder compositions, the ratio of the wet over dry tensile strength of said composition is about 0.5 or greater. The present invention further provides products coated or impregnated with the binder, such as heat-resistant fiberglass nonwovens used for insulation. The aqueous binder may further comprise one or more phosphorous-containing accelerator.

1 . A curable aqueous composition comprising: 
 100 weight parts of one or more than one binder chosen from: 
 (i) mixtures of one or more than one polycarboxylic acid or polymeric polyacid, each comprising at least two carboxylic acid groups, anhydride groups or salts thereof, and one or more than one polyol compound having a molecular weight of 1000 or less and comprising at least two hydroxyl groups or epoxy groups,  
 (ii) one or more copolymer or copolymeric polyacid including, as copolymerized units, one or more monomer bearing carboxylic acid groups or anhydride groups, and one or more hydroxyl group-bearing monomer, and  
 (iii) mixtures of (i) and (ii),  
   wherein, the said carboxylic acid groups, anhydride groups or salts thereof are neutralized to the extent of 35% or less with a fixed base, and, further    wherein, the ratio of the number of equivalents of the said carboxylic acid groups, anhydride groups or salts thereof in any of the said one or more than one binder to the number of equivalents of the said hydroxyl groups in the same said one or more than one binder is from 1/0.01 to 1/3, and    10 to 40 weight parts of one or more than one extender having an average particle size ranging from 0.5 μm or more and as high as 45 μm or less chosen from microcrystalline silica, diatomaceous silica, kaolin, bentonite, smectite, vermiculite, calcined aluminum silicate, anhydrous aluminosilicate clay delaminated wollastonite, calcium metasilicate, ground glass, nepheline syenite, hydrotalcite, and mixtures thereof,    wherein the wet over dry tensile strength of said composition is about 0.5 or greater.    
   
   
       2 . A composition as claimed in  claim 1 , further comprising one or more phosphorous-containing accelerator.  
   
   
       3 . A composition as claimed in  claim 1 , further comprising one or more emulsion polymer including, as copolymerized units, greater than 30 wt. %, based on the weight of the emulsion polymer solids, of an ethylenically unsaturated acrylic monomer including one or more C 5  or greater alkyl group.  
   
   
       4 . A composition as claimed in  claim 1 , wherein the said binder comprises binder (i) and the said polyol comprises one or more epoxy resin.  
   
   
       5 . A composition as claimed in  claim 1 , wherein the ratio of the hot-wet tensile strength to the dry tensile strength of said composition when cured is about 0.70 or greater.  
   
   
       6 . A composition as claimed in  claim 1 , wherein the said extender has been screened so as to pass through a screen having a grid size ranging from more than 0.5 μm to 45 μm and so as not to pass through a screen or filter having a grid size or lower resolution limit of 0.5 μm.  
   
   
       7 . A curable aqueous composition comprising: 
 100 weight parts of one or more than one binder chosen from one or more copolymer or copolymeric polyacid including, as copolymerized units, one or more monomer bearing carboxylic acid groups or anhydride groups, and one or more hydroxyl group-bearing monomer,    wherein, the said carboxylic acid groups, anhydride groups or salts thereof are neutralized to the extent of 35% or less with a fixed base, and,    further wherein, the ratio of the number of equivalents of the said carboxylic acid groups, anhydride groups or salts thereof in the said one or more than one binder to the number of equivalents of the said hydroxyl groups in the same said one or more than one binder is from 1/0.01 to 1/3, and,    10 to 40 weight parts of one or more than one extender having an average particle size ranging from 0.5 μm or more and as high as 45 μm or less chosen from microcrystalline silica, diatomaceous silica, kaolin, bentonite, anhydrous aluminosilicate clay delaminated, wollastonite, smectite, vermiculite, calcined aluminum silicate, wollastonite, calcium metasilicate, alkali aluminum silicate, ground glass, nepheline syenite, titanium dioxide, zinc oxide, mica, hydrotalcite, and mixtures thereof,    wherein the wet over dry tensile strength of said composition is about 0.5 or greater.    
   
   
       8 . A composition as claimed in  claim 7 , wherein the said extender has been screened so as to pass through a screen having a grid size ranging from more than 0.5 μm to 45 μm and so as not to pass through a screen or filter having a grid size or lower resolution limit of 0.5 μm.  
   
   
       9 . A composition as claimed in  claim 7 , wherein the said copolymer or copolymeric polyacid further comprises, as copolymerized units, one or more ethylenically unsaturated monomer having a solubility of less than 2 g/100 g of water at 25° C. in the amount of 3 to 25 wt. %, based on the total weight of monomers used to make the curable aqueous binder composition, the said ethylenically unsaturated monomer chosen from ethyl (meth)acrylate, methyl methacrylate, butyl (meth)acrylate, styrene, mono-alkyl (meth)acrylamide, and di-alkyl (meth)acrylamide.  
   
   
       10 . A non-woven heat resistant fibrous substrate coated or impregnated with the cured composition as claimed in  claim 1.