Patent Abstract:
A waterproof and insect and termite resistant composition comprising inorganic additives and polyester fibres dispersed in a curable and settable acrylate latex, whereby the composition when covering a point of entry of terminates to a building forms a termite barrier. The said composition impregnated into a construction fibre matting either formed in situ or preformed and sealed in place with the said composition across points of entry of termites to form a flexible, waterproof and insect and termite resistant barrier.

Full Description:
[0001]     This invention relates to an insect, more particularly termite and waterproof barrier.  
       BACKGROUND OF THE INVENTION  
       [0002]     Insects such as ants and termites can enter a building structure through very small openings, cracks and the like, often these gaps or openings not being readily discernable. While the invention is applicable to the provision of a barrier to insects the invention is particularly directed to the provision of a termite and waterproof barrier.  
         [0003]     Termites usually enter a building from the ground, and physical barriers have been proposed to prevent the entry of termites into the building. These include concrete slabs, ant caps on posts or pillars supporting the building, and steel mesh. These physical barriers can be used in combination with chemical termiticide treatment of the soil around the footings and penetrations.  
         [0004]     Recent concern about the environmental effect of various termiticides such as organophosphates and organochlorines have resulted in restrictions being placed on the use of chemical treatment of the soil and or building structure.  
         [0005]     It is an object of the invention to provide a physical barrier to prevent and or deter the entry of termites into a building.  
         [0006]     A further object of the invention is to provide a composition which can be applied to areas of a building to close a possible entry point into the building.  
         [0007]     A still further object of the invention is to provide a physical barrier in the form of a fabric coated or impregnated with the composition to close possible entry points.  
         [0008]     A still further object of the invention is to provide a coated or impregnated fabric and to adhere the fabric to the structure by an application of a layer of the composition.  
         [0009]     A still further object of the invention is to provide a termite and waterproof barrier having sufficient flexibility and elasticity to accommodate for any relevant movement between portions of the structure.  
       BRIEF STATEMENT OF THE INVENTION  
       [0010]     There is provided according to the invention a waterproofing and insect and termite composition comprising inorganic additives, fibres, and a curable or settable component such as an acrylate latex, whereby the composition when applied as a thick paint or coating forms when it cures a waterproof, flexible membrane resistant to insects and termites. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0011]      FIG. 1  is a view showing two possible entry points into a building,  
         [0012]      FIG. 2  is a view showing the barrier applied between two portions of the building,  
         [0013]      FIG. 3  shows one form of the fibre reinforced membrane,  
         [0014]      FIG. 4  shows the barrier applied to a brick veneer construction,  
         [0015]      FIG. 5  shows the barrier applied to an infill full brick construction,  
         [0016]      FIG. 6  shows an alternate barrier to the infill brick construction,  
         [0017]      FIG. 7  shows the barrier applied to foundation and footing slab, and  
         [0018]      FIG. 8  shows an alternate barrier to the foundation and footing slab.  
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0019]     The invention uses a composition that can be supplied in the form of a liquid, paste, gel or other similar form that can be applied to cracks, holes or gaps in building structures to form a waterproof and insect, particularly termite proof barrier.  
         [0020]     In its preferred form the composition comprises an acrylic latex with inorganic additives and polyester fibres dispersed in the latex to form a composition that is waterproof and self-curing, resistant to insects, particularly termite attack.  
         [0021]     One example of the composition can include  
                                                             % w/w                                        Calcium Carbonate   25           Polyester fibre   15           Styrene/butyl acrylate latex   40           Iron oxide pigment   2           Titanium dioxide   2.5           Plasticiser   1           Stabiliser   1           Biocide   0.1           Water   to 100%                      
 
         [0022]     In another preferred form of the invention another composition can include the following:  
                                                             % w/w                                        Styrene-acrylic polymer   60           Calcium Carbonate   25           Titanium Dioxide   5           Pigment   2           Propylene Glycol   2           Polymeric dispersant   1           Boric Acid   0.5           Water   up to 100%                      
 
         [0023]     In a still further preferred form of the invention the composition can include:  
                                                       Styrene-acrylic polymer   50           Calcium Carbonate   20           Glass Fibre   12           Titanium Dioxide   5           Pigment   5           Ethylene Glycol   3           Boric Acid   1           Dispersant   1           Biocide   0.15           Water   up to 100%                      
 
         [0024]     Preferably the fibres are chopped fibres typically with a length of 1-3 mm and a diameter of 0.01 to 0.1 mm although other lengths and diameters can be used. The fibres can be of any material that is inedible to termites such as nylon, polyester, polyethylene, polypropylene, glass fibre etc. Cellulose fibres are not suitable.  
         [0025]     The composition can be varied widely and still remain functional.  
         [0026]     The inorganic constituents can be varied in total amount, relative proportions and chemical composition. For any given chemical entity the amount can be varied from about 0% to about 50% of the total composition. The number of possible additives is vast and encompasses practically any inorganic salt, oxide or mineral. Practically, the choice is limited to readily available materials with low solubility in water, low toxicity, and no adverse environmental impact. Examples include calcium carbonate, titanium dioxide, iron oxides (haematite and magnetite), magnesium oxide, magnesium carbonate, silica, silicates etc. In addition it is possible to use other fillers such as plastic beads, metal filings, carbon (in the form of graphite, char, charcoal, carbon black etc) in place of or as well as inorganic constituents.  
         [0027]     The composition includes a settable or curable sealant. Suitable materials include acrylates, co-polymers, bitumen, water based silicones, polyurethane, chalking compounds, resins, latex and adhesives. The settable or curable sealant is essential to the performance of the product and can comprise 20 to 80% by weight of the product, typically about 40% to 60% by weight.  
         [0028]     Minor constituents of the composition include catalysts, plasticisers, UV stabilisers and biocides. These additives are well known in this type of application and can be selected from a wide variety of materials. For example, glycols, polyethylene glycols, surfactants and phthalate esters can function as plasticisers and stabilisers; isothiazolines and formaldehyde are well-known examples of biocides used in aqueous formulations.  
         [0029]     Many other minor additives can be incorporated in the product to modify its characteristics without altering its fundamental properties. For example, organic dyes or pigments could be used to extend the range of colours for decorative effects. Coarse materials such as sand or carborundum could be added to give the material non-slip properties. Most importantly termiticides could be added to enhance the termite resistant properties of the material. Examples of termiticides include organophosphates (such as chlorpyrifos) organochlorines (such as heptachlor), natural and synthetic pyrethroids (such as deltamethrin and permethrin) and inorganic compounds (such as compounds of arsenic, copper and boron).  
         [0030]     However, organic compounds such as organophosphates, organochlorines and pyrethroids are intrinsically chemically unstable and liable to lose efficacy over a period substantially less than the lifetime of the barrier or liable to leach out of the barrier into the local environment, which in the case of a cavity wall treatment could be most undesirable. Inorganic compounds have the virtue of remaining efficacious as long as the barrier remains intact i.e., for the lifetime of the barrier and not likely to leach out of the barrier over a period of time. Arsenic and copper are not considered to be environmentally acceptable and therefore the preferred additive is a boron containing compound. Examples of boron containing compounds include boric acid, borax, borates, tetraborates and borohydrates although without limitation thereto.  
         [0031]     The preferred boron-containing compound is boric acid. Preferably boric acid is present at concentrations of 2.0 g/kg to 80 g/kg or more. The preferred concentration is about 30 g/kg, more particularly 5 to 10 g/kg.  
         [0032]     The composition can be used in conjunction with construction materials such as stainless steel mesh, fibre glass, woven plastic mesh (such as shade cloth, flywire, and the like) geotextile and other similar fabrics to form a water proof and insect, particularly termite, proof damp course and termite barrier in building cavities.  
         [0033]     When used in conjunction with building materials such as geotextile fabric, the composition can be coated to the fabric in-situ, or the fabric can be precoated and supplied in a cured form as a waterproof, termite-proof membrane. In either case the membrane is made to adhere to the building materials by application of the composition in a liquid form followed by either the prepared membrane or the freshly coated fabric. The membrane when coated with the composition and cured is flexible, has good tensile strength so that it cannot be easily torn. Also the membrane has a slight degree of elasticity. The following example will serve to clarify the method of application of the composition:  
         [0034]     Referring to  FIG. 1  illustrating a concrete slab  1  formed with a minor crack  2  and a construction joint  3  several millimetres wide. Both the crack  2  and the construction joint  3  provide points of entry for termites and/or moisture.  
         [0035]     The crack can be sealed by applying the composition with a brush, roller or spray gun to form a continuous barrier at least 2 mm thick and several mm wide to form a flexible, durable barrier to moisture and insects. The composition can also be applied with a spatula or similar tool to force material into the crack and form an even more efficacious barrier.  
         [0036]     However a construction joint cannot be sealed in this way and either of the following methods can be used.  
         [0037]     Turning now to  FIG. 2  the composition  4  is applied to either side of the construction joint with a brush, roller, spray, spatula or other similar means. A piece of construction fabric  5  is first coated with the composition on one side, is then applied across the construction joint, coated side towards the concrete. A second coat is then applied across the fabric and the concrete so as to form a continuous waterproof, insect-proof barrier. It will be realised the drawings are illustrations only of the invention and thickness have been exaggerated for illustration purposes.  
         [0038]     Alternatively the construction fabric can be pre-coated and cured and applied to the construction joint after the initial application of the composition to the concrete as described above. In this case, the barrier is completed by applying a second coat of the composition to the membrane after placing the prepared material across the construction joint, paying further attention to the edges of the membrane.  
         [0039]     A further refinement of the technique is shown in  FIG. 3 . This is applicable to sealing wall cavities and the like. The membrane  6  is prepared with the cured coating of the composition in a continuous roll with one or both edges  7  left uncoated. The pre-coated material can be cut to length as required, with the untreated edge of edges facilitating sealing the membrane to the concrete slab or to other construction material.  
         [0040]     The invention when formed into a membrane by coating a construction material such as construction fabric whether pre-formed or formed in-situ can be described as a fibre-reinforced membrane. Thus the strength of the construction fabric is greatly enhanced by the fibres in the composition applied to the fabric.  
         [0041]     Further examples of the application of the invention will now be described. The method of applying the membrane is as described above. The preferred form of the membrane is a pre-coated strip with one or both edges left untreated.  
         [0042]     In  FIG. 4  the invention is applied to a brick veneer building on a monoslab foundation  9  having a stepped portion  10 . The membrane  8  is positioned between one course of bricks  11  and between the bottom member  12  of the internal wall of the building. The membrane is rolled out, cut to length and sealed to the adjacent bricks and the concrete slab.  
         [0043]     A further building construction is shown in  FIG. 5 . The building is a full brick construction having outer wall  13  and inner wall  14 . The foundation is of in-fill construction with a perimeter foundation  15  supporting the outer wall  13  and an in-fill wall  16 . The concrete flow slab  17  of the building is supported on the in-fill wall portion  16 . The membrane  8  is positioned between a course of bricks in the outer wall  13  and between the lowest course of the bricks of the inner wall  14  and the floor slab  17 . In addition membranes  8   a  and  8   b  can be positioned and sealed by applying layer of the composition to the lower portions of the walls  13  and  16  and applying the membranes  8   a  and  8   b , the flexibility of the membranes permitting it to be bent and be sealed against the top surface of the foundation  15 . The membrane  8   b  extends up to and is also sealed to the lower side portion of the floor slab  17 .  
         [0044]     An alternate treatment of the building of  FIG. 5  is shown in  FIG. 6 . In this instance the membranes  8   a  and  8   b  are not positioned against the lower surfaces of the walls  8  and  16 , the protection of the building being provided by the membrane  8  bridging between the walls  13  and  14 .  
         [0045]      FIG. 7  shows the application of the membrane  8  to extend between a course of bricks in the outer wall  18  to the top surface of a footing slab  19  beneath the inner wall  20 . The footing slab rests on the perimeter foundation  20 .  
         [0046]     Extra protection to the building can be provided as shown in  FIG. 8  by the application of membranes  8   c  and  8   d . Membrane  8   c  seals between the outer wall  18  and the foundation  20 , while membrane  8   d  seals between the foundation  20  and the footing slab  19 .  
         [0047]     In an alternate construction the membrane  8  bridging the gap between the outer wall and the inner wall can be omitted, the protection being provided by membranes  8   c  and  8   d.    
         [0048]     The composition has many other applications in building construction and other areas.  
         [0049]     Timber treatment, including posts and poles. In this application the composition can be applied direct to the timber as a waterproof, insect-proof coating or can be applied in conjunction with a fabric “sock” in the case of posts and poles to form a more efficacious system. It can be applied to bridging timbers especially abutment timbers. The composition can be used as a waterproof and termite resisting paste or glue for other construction materials, including stainless steel mesh, stainless steel sheeting, and light aluminium.  
         [0050]     The composition can be used as a waterproofing material for general construction, to repair material breaches in damp courses and physical termite barriers, and as a waterproofing sealant in marine applications, for concrete, galvanised metal and other water holding tanks.  
         [0051]     Thus there is provided according to the invention a composition which provides a waterproof and insect and vermin proof barrier. Although the composition can include a termiticide, as an alternative additive the barrier is provided without any such additive. The composition is self curing, and when applied to a material such as construction fabric forms a strong flexible membrane. The composition is self adhering to all surfaces and thus to seal the membrane to a surface, the composition itself can be used without the necessity of a separate adhesive.

Technology Classification (CPC): 4