Title of Invention

A WATER BASED COATING/FLOORING COMPOSITION CONTAINING EMULSIFIED EPOXY RESINS

Abstract

A stabilized oil in water emulsion The present invention relates to a stabilized oil in water emulsion capable of being used as coating/flooring composition comprising: 1) diglycidyl ether of Bisphenol in combination with ethoxylated nonyl-phenol and sodium lauryl sulphate, 2) at least one hardener consisting of water soluble/dispersible polyamide resin and a polyamine and at least one known filler material.

Full Text

This invention relates to a water based coating/flooring composition containing emulsified epoxy resins. This coating/flooring where an epoxy' resin emulsion was used as a base may be self levelling in nature. Coating compositions containing epoxy resins are widely used in civil engineering industry. The products known in the art exhibit excellent mechanical and physical properties and are used as floor coatings and as protective coatings for cementious substrates. However, the hitherto known compositions possess very high volatile organic compounds emission rate which no doubt is a potential health hazard. Use of environmentally harmftil solvents must therefore be minimised to meet the stringent requirements of the changing environmental protection regulations. Consequently, efforts are made to develop green products which are environmentally compatible. In the case of coating composition an effective way to reduce volatile organic compound content is by using water as a liquid phase. Prior to the enforcement of environment regulations a typical epoxy coating composition was made from high molecular weight curing agent cross linked with high molecular weight epoxy resins and are solvent based for easy application. Water based epoxy resin compositions are preferred over conventional solvent based products as they have near zero volatile organic compound content, are almost odourless, and are non-inflammable. Water based compositions of our invention are easy to clean up, exhibit good adhesion especially to damp or green concrete, have low viscosity and show good abrasion resistance. The water based epoxy resin composition developed by us uses an oil-in-water type emulsion as a base material. An appropriate hardener and suitably graded fillers are also used. The oil-in-water emulsion may contain a small quantity of organic solvents. The epoxy resins used in the composition is a diglycidyl ether of Bisphenoi A based unmodified resin with an epoxy content between 5.1 to 5.6 having a viscosity of 9000 to 12000 cp. Bisphenoi A base resin modified with monofunctional aromatic reactive diluent with an epoxy content between 5.2 to 5.5, liquid epoxy novolac resin based on bisphenoi F and epichlorohydrin with an epoxy equivalent wt of 170 to 190, and a 75% xylene solution of unmodified Bisphenoi A based resin of low molecular weight having an epoxy value of 1.9 to 2.2 may also be used for preparation of said emulsion. Emulsion is prepared by adding an ionic/non-ionic emulsifier such as a combination of nonyl-phenol ethoxylate and a sodium salt of lauryl ether sulphate to any of the epoxy resins referrenced herein above and emulsifying the mixture under agitation while adding water thereto. A high shear mixer may be used for agitating and emulsifying the mixture. At low volume phases a highly viscous water-in-oil emulsion is formed which undergoes a catastrophic 'phase inversion' to form a stable oil-in-water type emulsion at a higher volume phase ratio. The water content of the emulsion may vary from 25 to 75%. Conventional protective colloids and defoamers may be added at the final stage of emulsification. Hardeners used in the compositions must have a water soluble/dispersible polyamide resin with low free amine and high reactivity. The desired hardener must provide improved adhesion, and good stability to the concrete. Floor coatings with high gloss to matt finish can be produced by using the hardener either alone or in combination with benzyl alcohol. Atypical hardener formulation is represented herein below: Benzyl alcohol - 40-60 parts by wt. Polyamide - 20-30 parts by wt. Polyamine - 20-30 parts by wt. Defoamer - 0.05 to 3 parts by wt. The following hardeners may effectively be used in the subject composition. 1. Isophorone diamine 2. Tris 2,4,6 (dimethylaminoethyl) phenol 3. Polyamides with 180 - 600 cps 4. Ethylene diamine in ethylene glycol monoethyl ether 5. 2,4,4-trimethylene hexamethylane diamine 6. Epoxy functionalised aromatic amine accelerator. The grades and the choice of fillers are also important in achieving the desired qualities of the final composition. Generally a self levelling flooring composition must have the following fillers. 1. Silica flour (40 to 100 microns) 40 to 50% 2. Quartz (o.l to 0.3 mm) 55 to 70% Mica powder and Barytes may preferably used as filler. The oil-in-water emulsion mav have the following; non-ionic « tar' surfactants: 1. Sorbitan mono oleate/polyoxythylene sorbitan mono oleate 2. Ethoxylated alcohols such as cetyl, cetostearyl, lauryl, oleyl and stearvl alcohols either alone or in combination with each other. 3. Nonyl phenol ethoxylate (8-9 mols of ethylene oxide units preferably). lonoic surfactants capable of being used in this composition are 1. Sodium stearate which may be fonned in situ. 2. Sodium lauryl sarcosinate and 3. Sodium lauryl ether sulphate. Defoamers that may be used according this invention are: 1. Tributyl phosphate, 2. Polyethylene glycol with mol wt in the range of 200 to 600, 3. Dimethyl polysiloxane emulsion, 4. Methyl isobutyl ketone and 5. Higher alcohols such as octanol and dicanol. Protective colloids that can be added to the composition are (1) Sodium alignate (2) gum accacia and (3) polyvinyl alcohol solution. An aqueous solution with 15% strength is preferred. A typical oil-in-water emulsion forming the base of the composition contains the following: Diglycidyl ether of Bisphenol A - 30 to 60% Nonyl phenol ethoxylate with 8 to 9 mols of ethylene oxide 0.5 to 3% Sodium lauryl ether sulphate - 0.5 - 3% Water - 20 to 40% Defoamers -0.5 to 4% 15% solution of polyvinyl alcohol as protective colloid 0.1 to 2%. Required pigments may also be added to this emulsion. The water based coating composition containing emulsified epoxy resins according to this invention comprises (1) an oil-in-water emulsion of diglycidyl ether of Bisphenol, at least one known ionic/non-ionic emulsifer and water; (2) at least one hardener consisting of water soluble/dispersible polyamide resin with low free amine content and a polyamine, and (3) and known fillers. The weight ratio of the oil-in-water emulsion and the hardener to the weight ratio of the filler is preferably in the range of 1.0/0.3 to 1.0 to 1.0. The range of the hardener to the filler is from 0.1/1.0 to 0.8/1.0. The water content in the emulsion may vary from 25 to 75%, During the final stages of emulsification, other ingredients such as, the protective colloids and defoamers mav be added. This invention will now be described with reference to the following illustrative example. 100 gm of the oil in water emulsion of the epoxy resin is added to a mixture of 50/50 parts of polyamine and polyamide. The resulting mixture is stirred for about 5 minutes. 100 gms of a mixture containing silica flour of 40-100 microns and quartz of 0.1 to 0.3 mm are then added and the mixture homogenized thoroughly for an additional period of five minutes. A suitable coating composition may have the following percentage composition. Oil-in-water emulsion and hardener 25 to 30% Solvents 1 to 3% Fillers 15 to 30% Pigments 4 to 10% Water 30 to 40% The weight ratio of the oil-in-water emulsion and the hardener to the weight ratio of the filler is preferably in the range of 1.0/0.3 to 1.0 to 1.0. The range of the hardener to the filler is fi-om 0.1/1.0 to 0.8/1.0. The water content in the emulsion may vary fi'om 25 to 75%. During the final stages of emulsification, other ingredients such as, the protective colloids and defoamers mav be added. This invention will now be described with reference to the following illustrative example. 100 gm of the oil in water emulsion of the epoxy resin is added to a mixture of 50/50 parts of polyamine and polyamide. The resulting mixture is stirred for about 5 minutes. 100 gms of a mixture containing silica flour of 40-100 microns and quartz of 0.1 to 0.3 mm are then added and the mixture homogenized thoroughly for an additional period of five minutes. A suitable coating composition may have the tbllowing percentage composition. Oil-in-water emulsion and hardener 25 to 30% Solvents 1 to 3% Fillers 15 to 30% Pigments 4 to 10% Water 30 to 40% WE CLAIM: 1. A stabilized oil in water emulsion capable of being used as coating/flooring composition comprising: 1) 30% to 60% of diglycidyl ether of Bisphenol in combination with 0.5% to 3% of ethoxylated nonyl-phenol and 0.5% to 3% of sodium lauryl sulphate, 2) at least one hardener consisting of water soluble/dispersible polyamide resin and a polyamine and at least one known filler material. 2. The stabilized oil in water emulsion as claimed in claim 1, wherein said dyglycidyl ether is selected from unmodified Bisphenol A with an epoxy content of 5.1 to 5.6 having a viscosity in the range of 9000 to 12000 cp, Bisphenol A with modified monofunctional aromatic reactive groups with an epoxy content of 5.2 to 5.5, liquid epoxy novolac resin based on Bisphenol F and epichlorohydrin having an epoxy equivalent weight of 170 to 190; and a 75% solution of unmodified Bisphenol A resin of low molecular weight in xylene having an epoxy value of 1.9 to 2.2. 3. The stabilized oil in water emulsion as claimed in claims 1 and 2 wherein said hardener is selected from Isophorone diamine, Tris 2,4,6 (diaminomethyl) phenol, polyamides with a viscosity of 180 to 600 cps. Ethylene diamine in ethylene glycol monoethyl, 2,4,4-trimethylene diamine, and epoxy functionalised aromatic amine accelerator. 4. The stabilized oil in water emulsion as claimed in claims 1 to 3, wherein said fillers are selected from silica flour of 40 to 100 microns, quartz of 0.1 to 0.3 mm, mica powder and Barytes. 5. The stabilized oil in water emulsion as claimed in claims 1 to 4 also containing known defoamers protective colloids and pigments. 6. The stabilized oil in water emulsion as claimed in claim 5, wherein said defoamers are selected form tributyl phosphate, polyethylene glycol having a molecular weight range of 200 to 600, an emulsion of dimethyl polysiloxane, methyl isobutyl ketone, and higher alcohols such as octanol and decanol. 7. The stabilized oil in water emulsion as claimed in claim 5, wherein said protective colloids are selected from sodium alignate, gum accasia and a solution of polyvinyl alcohol preferably of 15% strength. 8. The stabilized oil in water emulsion as claimed in claims 1 to 7 comprising 25 to 30% of said oil in water emulsion and hardener, 1 to 3% of a known organic solvent, 15 to 30% of fillers, 4 to 10% of pigments and 30 to 45% of water. 9. The stabilized oil in water emulsion as claimed in claims 1 to 8, wherein said oil-in-water emulsion consists of 30 to 60% diglycidyl ether of Bisphenol 0.5 to 3% nonyl phenol ethoxylate, 0.5 to 3% of sodium lauryl ether sulphate, 20 to 40% of water, 0.5 to 4% of know defoamers, and 0.1 to 2% of known protective colloids. 10. A stabilized oil in water emulsion substantially as herein described.

Documents:

814-mas-2000-abstract.pdf

814-mas-2000-claims filed.pdf

814-mas-2000-claims granted.pdf

814-mas-2000-correspondnece-others.pdf

814-mas-2000-correspondnece-po.pdf

814-mas-2000-description(complete) filed.pdf

814-mas-2000-description(complete) granted.pdf

814-mas-2000-form 1.pdf

814-mas-2000-form 26.pdf

814-mas-2000-form 3.pdf

814-mas-2000-other documents.pdf