Field of the invention

[0001] The present invention relates to the nano-coat formulation.

More particularly, the present invention relates to a composition and method of making nano-coat formulation for corrosion resistance in rebars.

Background of the invention

[0002] Corrosion is a major problem for all types of steel and RCC structures. Moreover, with the increase in the prices of steel, protection of the steel and its structure from corrosion has become mandatory and gained further importance. As the steel rebars in concrete are the most vital element in RCC structure and are even prone to corrosion. Ultimately the protection of steel rebars gains the most importance.

[0003] The rebars in RCC structures of coastal areas face the problem of corrosion more than any other region. Hence the same structures needat most protection against rusting or corrosion with higher bonding to concrete.

[0004] The rebar corrosion is concerned, the rate of corrosion depends on several factors such as the type and surface configuration of rebars, the type of cement employed in the mortar, the dose of concrete, the permeability of concrete, the presence of cracks and fissures, humidity of concrete, and, most importantly, in the presence of contaminants and aggressive species such as 02, Cl- C02, S02, S2-, SO42-, etc., In general, aggressive actions of chloride ions and carbonation of concrete environment are the main factors which cause concrete corrosion.

[0005] The patent document US9469769B 1 describes the anticorrosion treatment composition for steel rebar embedded in concrete as a composition for coating steel rebar before the steel rebar is embedded in concrete. The coating of the steel rebar with the anti-corrosion treatment composition forms a treatment film on the steel rebar which controls both uniform corrosion and pitting corrosion of the steel rebar after it has been embedded in the concrete. The anticorrosion treatment composition includes an inorganic acid, an organic acid, polyethylene glycol, and water. The inorganic acid forms between approximately 3.9 wt % and approximately 15.0 wt % of the anti-corrosion treatment composition, the organic acid forms between approximately 0.1 wt % and approximately 2.9 wt % of the anti-corrosion treatment composition, the polyethylene glycol forms between approximately 2.0 wt % and approximately 10.7 wt % of the anti-corrosion treatment composition, and the remainder of the anti-corrosion treatment composition is water.

[0006] Prior art US Patent No 6395110, which teaches of a copperbased alloy having a composition of Cu, Pb, P, Su, and Ni, at various proportions but the composition could not teach the use of Va, W which provides high strength, high bonding capacity, and highly corrosive resistance capacity.

[0007] The patent document CN104743953B discloses a low-cost rebar corrosion inhibitor and belongs to the technical field of building materials. The corrosion inhibitor is compounded of corrosion inhibition components (sodium benzoate, sodium acetate, thiocarbamide and magnesium oxide) and water serving as a dispersion medium, wherein sodium benzoate is an organic type corrosion inhibition component and belongs to anodic corrosion inhibition components; sodium acetate and thiocarbamide are organic type corrosion inhibition components and belong to mixed-type corrosion inhibition components; magnesium oxide is an inorganic type corrosion inhibition component; therefore, the corrosion inhibitor disclosed by the invention is compounded of the organic and inorganic corrosion inhibition components and also is a mixture and a composition of the anodic corrosion inhibition component and the mixed type corrosion inhibition component, so that the prepared corrosion inhibitor has obvious inhibition effects on the anodic reaction and cathodic reaction in the rebar corrosion process, the defects of singly using organic or inorganic corrosion inhibition component is overcome. The corrosion inhibitor is low in price, low in use amount, non-toxic and pollution-free, and can be used in a way of being directly mixed with concrete, is well adapted to the concrete, and can be widely applied to the reinforced concrete structure of water conservancy, railways, and civil buildings. [0008] Existing technologies of coating RCC rebar include the methods like fusion bonded epoxy coating, which requires a specific plant, high cost of application gives better corrosion resistance but decreases bonding of concrete with steel not convenient for coating on-site in remote areas.

[0009] Another method is Cement polymer composite coating

(CPCC) which describes the application of cement slurry with bonding polymer by a dipping process. Gaps in coating accelerate corrosion on rebar and concrete to concrete bonding is not adequate.

[0010] Use of paints for corrosion resistance not specified by IS code. It does not give adequate bonding of coated rebars with steel.

[0011] To overcome the existing problems faced by the prior art, there is a need to provide a composition and method of making nano-coat formulation for corrosion resistance in rebars.

Objects of the invention

[0012] The object of the present invention is to provide a composition and method of making nano-coat formulation for corrosion resistance in rebars. [0013] One more object of the present invention is to provide a composition and method of making nano-coat formulation for corrosion resistance in rebars that has a short coating time.

[0014] Another object of the present invention is to provide a composition and method of making nano-coat formulation for corrosion resistance in rebars that provides better rust resistance.

[0015] Yet another object of the present invention is to provide a composition and method of making nano-coat formulation for corrosion resistance in rebars that is economical and eco-friendly.

[0016] Yet another object of the present invention is to provide a composition and method of making nano-coat formulation for corrosion resistance in rebars that is suitable for the coastal and seismic region.

Summary of the invention

[0017] According to the present invention there is provided a composition and method of making nano-coat formulation for corrosion resistance in rebars. The composition comprises of tungsten (T) and derivative of Tungsten based and /or alkali of the component which is taken in the range of 10-30% of the total weight, Vanadium (V), and alkali derivative of Vanadium such alkali Vanadate is taken in the range of 5-25% by weight of the composition, Sodium Nitrate (NaNCh) taken in the range of 10-30% and Calcium Nitrite CaiNChh taken between 10-30%. Water is used as a base for making the composition. In order to give color, fluorescence is used and color such as pink, and blue is used in the composition.

[0018] Further a method of preparing the composition is provided. The method describes pouring steel guard nano-coat liquid in a tank, the tank is free from oil grease dust or any other impurities.

[0019] In the next step, the bundles of steel rebars or single rebars as per requirement and of the desired size are taken and are made dry and free from oil grease dust or any other impurities on the surface. In the next step the rebars are directly dipped into the composition for 1-2 minutes and every part of steel is brought in contact with the composition.

[0020] In the further step, the rebars are removed from the composition and kept in a tilted position for removal of excess liquid therefrom.

[0021] Finally, the rebars are dried for up to 1-2 hours and cured for 3-4hours. Once the rebars are touch dry and cured, they are ready for further use in RCC structures.

Detailed description of the invention

[0022] An embodiment of this invention, illustrating its features, will now be described in detail. The words "comprising," "having," "containing," and "including," and other forms thereof, are intended to be equivalent in meaning and be open-ended in that an item or items following any one of these words is not meant to be an exhaustive listing of such item or items or meant to be limited to only the listed item or items.

[0023] The terms “first,” “second,” and the like, herein do not denote any order, quantity, or importance, but rather are used to distinguish one element from another, and the terms “a” and “an” herein do not denote a limitation of quantity, but rather denote the presence of at least one of the referenced items.

[0024] The present invention discloses a composition (100) and method (200) of making nano-coat formulation for corrosion resistance in rebars. The composition (100) is corrosion resistant and gives high bonding strength composition, improved anti-rust resistance, highly stable, high strength composition with a formulation made especially for Mild Steel (RCC REBARS), and the reactions in the formulation get activated as soon as it comes in contact with Mild Steel.

[0025] In a present embodiment, tungsten (T) and derivative of

Tungsten based and/or alkali of the component which is taken in the range of 10- 30% of the total weight, more particularly the range taken in 22-27% by weight of the composition is taken. The composition (100) further contains Vanadium (V), and alkali derivative of Vanadium such as alkali Vanadate taken in the range of 5- 25% by weight of the composition more particularly between 12-18% or can be between 12-15%. Sodium Nitrate (NaNCh) is taken in the range of 10-30%, particularly between 17-20% more particularly 17-20. Finally, Calcium Nitrite CafNChh is taken between 10-30% particularly selected between 14-25% more particularly 15-17%.

[0026] In another embodiment the proportion of Tungsten (T)

Derivative is 26%, Alkali Vanadate is 15%, (NaNCh) is 17%, Ca(NO2)2 is 14% and water is 28%.

[0027] Water is used as a base for making the composition (100). In order to give color, fluorescence can be used and the color such as pink, or blue would be used in the composition (100).

[0028] Then, the addition of Vanadate (V), Sodium Nitrate

(NaNO3) process under constant stirring at room temperature is done. Further to this, Calcium Nitrite Ca(NO2)2 was added under room temperature for 10 minutes to make the formulation followed by the addition of color and color pigments into the composition. The results are achieved by the present invention in comparison with traditionally coated composition are enumerated as follows. Therefore, the present invention is advantageous over the prior art.

[0029] The composition (100) is applied on the which penetrates the surface of the steel rebar to be used for construction purposes into the very fine cracks, holes, and crevices of the steel where it reacts with the bare surface of iron to form complex water-insoluble compounds in the form of a very tenacious layer which becomes an inseparable part of iron which in due course protects the steel from rusting results high strength.

[0030] The composition (100) does not allow the iron to form Fe ions and stops the initiation of rusting. Further, the water repellent formula of the steel guard complies and does not allow water to invade the steel. The composition (10) stops corrosion in four different manners by stopping the formation of Fe2+ ions, forming a fine and tenacious coat on the surface of the steel, checking in the grace of water, and fights against atmospheric pollution. [0031] The composition (100) comes into contact with steel, it reacts with Fe2+ and Fe3+ ions and bonds them in such a way that the further conversion of Fe2+ and Fe3+ ions into hydroxy carbonates is highly useful in preventing rust and consequently enhances high bonding strength in the structure.

[0032] Simultaneously billions of nuclei are formed on the surface and micro-crystals start growing around them. This forms a very tenacious attachment with the substratum resulting in the formation of a highly complex crystalline structure on the steel surface.

[0033] During this process, a dense forest of micro-crystals is developed on the steel surface, which has a great affinity towards cement as well as steel. Finally, the composition (100) becomes an inseparable part of steel, remains unaffected even at 300 degrees Celsius, and is also stable in sub-zero temperatures up to - 196 degrees.

[0034] Micro Crystal Development Theory (MCDT) described above indicates that each crystal nucleus of the composition (100) has the power of attracting other cement molecules to it by the virtue of crystal forces and it forms a TRAP for all these molecules which do not possess sufficient energy to escape.

[0035] Chemisorption, another important reaction takes place during the formation of a reaction where molecules are held on a steel surface by chemical bonds formed between composition and steel molecules, here heat of absorption is high and is very difficult to reverse the process i.e. only heating to high temperature can reverse the chemisorption’s. [0036] Each crystal of steel complex is cubic shaped (like a crystal of diamond) with 4 threefold axes which help to increase adherence to steel and concrete resulting in enhancing brushing structure.

[0037] The composition (100) is generated from the metal itself and is an inseparable part of the mild steel. As the relation of bonding of the steel with concrete in RCC structure, in which the beam and the compression lead is taken by the concrete and tensile load is taken by steel when the beam is laded. These compression stresses in concrete and tensile stresses in steel act as a clanking couple to counteract the applied load but this happens only when there is a perfect grip between steel and concrete. Hence bond strength is important.

[0038] If such bonding strength between the concrete and steel is not achieved, it happens just as a steel rod is pierced into an oversized bore of concrete. This ultimately decreases the power and strength of the beam and consequently collapses.

[0039] Such a situation occurs when the steel rods are not protected by the composition application. The uncoated bars come in direct contact with moisture and water, resulting in direct corrosion on the surface of the steel rod which separates the rod and the bonding cement slurry, which results in bond or grip stresses. This causes the rod not to get a "stress transfer phenomenon". Hence the beam loses its strength and gets demolished even if sufficient reinforcement is provided. The composition (100) prevents all such recurrences only because the composition (100) prevents rusting process and keeps bond stress intact. The formulation for preparing 1000 ml of composition (100):

1) Formulation 1

2) Formulation 2

[0040] The water-based composition (100) is produced by using the following method (200). The method (200) is explained in conjunction with the composition (100) for the brevity of the invention.

[0041] The method (200) begins at step 10. [0042] At step 20: a steel guard is poured into a nano-coat liquid tank, the tank is free from oil grease dust or any other impurities.

[0043] At step 30: the bundles of steel rebars or single rebars of desired sizes are taken as per requirement and are made dry and free from oil grease dust or any other impurities on the surface.

[0044] At step 40: the rebars are dipped directly into the composition (100) for 1-2 minutes.

[0045] At step 50: the whole surface area of the rebar is brought in contact with the composition (100).

[0046] At step 60: the rebars are removed and kept in a tilted position for the removal of excess liquid on them.

[0047] At step 70: the rebars are dried for 1-2 hours maximum and cured for 3-4 hours. Once the rebars are touched dry and cured are then ready for further use in RCC structures.

[0048] The method (200) ends at step 80.

[0049] Further, the addition of all the active ingredients in water is kept aside for lOminutes, and the addition of Vanadium (V), Sodium Nitrate (NaNOs) is done under constant stirring at room temperature. Further to this Calcium Nitrite Ca (NO2).’. is added at room temperature for 10 minutes followed by the addition of colour and color pigments into the composition. [0050] The foregoing descriptions of specific embodiments of the present invention have been presented for purposes of illustration and description.

They are not intended to be exhaustive or to limit the present invention to the precise forms disclosed, and obviously, many modifications and variations are possible in light of the above teaching. The embodiments were chosen and described to best explain the principles of the present invention and its practical application, and to thereby enable others skilled in the art to best utilize the present invention and various embodiments with various modifications as are suited to the particular use contemplated. It is understood that various omissions and substitutions of equivalents are contemplated as circumstances may suggest or render expedient, but such omissions and substitutions are intended to cover the application or implementation without departing from the scope of the claims of the present invention.