Claims:We claim:
1. Synthesis of copper sulfide nanostructures on brass coated steel cords used in radial tires under ambient conditions, with a chemical compound of formula CuxS (where x varies from 1-2) obtained through ambient electrospray treatment of elemental sulphur (S) on Brass-Coated Steel Cords (BCSC) at a temperature between room temperature and 1100˚C, the said method comprising the steps of:
i) placing a platinum wire each inside a plurality of glass capillaries (101a, 101b, 101c) and placing a BCSC below the said plurality of glass capillaries (101a, 101b, 101c), at a distance of 1-5 cm, wherein the said set-up is at a temperature between room temperature and 1100˚C;
ii) refluxing 10-50 mg of a sulphur precursor in 10-100 mL of an organic solvent followed by purging the solution obtained to obtain a precursor solution of sulphur;
iii) transferring the said precursor solution of sulphur into the said plurality of glass capillaries using a micropipette;
iv) performing electrospray treatment for about 25-30 minutes by applying high voltage to the platinum wire and grounding the BCSC through a motor while simultaneously rotating the BCSC;
characterised in that a spray plume is generated from the tip of the glass capillaries (101a, 101b, 101c) consisting of sulphur containing species which react with the Copper from the BCSC to form CuxS, which is copper sulphide nanostructure coated on the said BCSC, wherein x is ~ 2.
2. The method of synthesizing a chemical compound of formula CuxS as claimed by Claim 1 wherein the electrosprayed BCSC is stored in vacuum or nitrogen or inert environment before vulcanising with rubber compound.
3. The method of synthesizing a chemical compound of formula CuxS as claimed by Claim 1 wherein the said sulphur precursor is sulphur powder.
4. The method of synthesizing a chemical compound of formula CuxS as claimed by Claim 1 wherein the refluxing 10-50 mg of the sulphur precursor in 10-100 mL of an organic solvent is at 120˚C for 10 hours.
5. The method of synthesizing a chemical compound of formula CuxS as claimed by Claim 1 wherein the refluxing is followed by purging the solution obtained with nitrogen.
6. The method of synthesizing a chemical compound of formula CuxS as claimed by Claim 1 wherein the refluxing is followed by purging the solution obtained with an inert gas.
7. The method of synthesizing a chemical compound of formula CuxS claimed by Claim 1 wherein the said sulphur precursor is a sulphur containing organic or inorganic material.
8. The method of synthesizing a chemical compound of formula CuxS as claimed by Claim 1 wherein the concentration of the said sulphur precursor is between one nanomolar to 1000 millimolar.
9. The method of synthesizing a chemical compound of formula CuxS as claimed by Claim 1 wherein the said organic solvent is selected from a group comprising of toluene, hexane, methanol, ethanol, benzene, and carbon disulfide.
10. An apparatus (100) for synthesis of copper sulfide nanostructures in brass coated steel cords used in radial tires under ambient conditions, the chemical compound of formula CuxS obtained through the method as claimed in Claim 1, the said apparatus (100) comprising of:
i) a plurality of glass capillaries (101a, 101b, 101c), wherein each of the said glass capillaries (101a, 101b, 101c) consist of a platinum wire (102a, 102b, 102c) placed inside;
ii) a Brass-Coated Steel Cord (BCSC) (103) positioned below the said glass capillaries at a distance of 1-5 cm, the said BCSC (103) being connected to a motor (104), the said motor (104) facilitating the constant rotation of the said BCSC.
11. The apparatus (100) for synthesizing a chemical compound of formula CuxS as claimed by Claim 10 wherein the said plurality of glass capillaries (101a, 101b, 101c) have an inner diameter of 20 to 25 mm.
12. The apparatus (100) for synthesizing a chemical compound of formula CuxS as claimed by Claim 10 wherein the said plurality of glass capillaries (101a, 101b, 101c) are made by pulling a borosilicate glass capillary using a micropipette puller.
Dated this 18th day of October, 2021
Kalyan Jhabakh
(Agent for Applicant)
IN/PA-830

, Description:SYNTHESIS OF COPPER SULFIDE NANOSTRUCTURES IN BRASS COATED STEEL CORDS USED IN RADIAL TIRES UNDER AMBIENT CONDITIONS
FIELD OF THE INVENTION
The present invention relates to synthesizing copper sulfide nanostructures on Brass- Coated Steel Cords (BCSC) which are used in the reinforcement of the ply region in radial tires. In particular, the invention relates to a method of synthesising copper sulfide nanostructures (CuxS, where x varies from 1-2) on BCSC through electrospray droplet synthesis under ambient conditions, which when formed ex-situ and incorporated into the rubber matrix, reduces vulcanization time and lowers the quantity of sulphur used in tires.
BACKGROUND
Generally, in radial tires the ply region experiences maximum stress and is prone to deformation. Brass-coated Steel Cords (BCSC) are used as reinforcing materials to overcome such deformities. At room temperature and atmospheric pressure, BCSC do not adhere with the rubber compound and upon vulcanization, an interface composed of metal sulfide nanostructures is formed leading to adhesion. Usually, copper sulfides are formed in-situ on BCSC during vulcanization. Further, conventional methods that produce an interface ex-situ require subjecting BCSC to a very high temperature, which has several disadvantages.
In recent years, many attempts have been made to fabricate metal sulfide nanostructures on BCSC through flame pyrolysis technique. This method suffers from a series of limitations with regard to the feasibility and environmental damages incurred when sulphur donating precursors are used. Surface temperature of BCSC (between 100 to 350 °C) incurs an additional manufacturing cost and free radicals produced by the sulphur donating precursors pose a serious trouble in commercialising this methodology.
US9694517 discloses a ready-for-use metal reinforcer capable of adhering by vulcanization to an unsaturated rubber matrix, wherein the ready-for-use metal reinforcer comprises a surface provided with nanoparticles of at least one sulfide of a metal selected from the group consisting of cobalt, copper, iron, zinc, and alloys comprising at least one of these elements. The metal reinforcers can be used in the metal/rubber composites intended in particular for the manufacture of finished articles made of rubber, such as hoses, belts, plies or tires, and also in the processes for the surface treatment of these metal reinforcers for the purpose of making it possible for them to adhere to unsaturated rubbers, such as natural rubber. The reinforcer of the invention can be obtained by flame spray pyrolysis (FSP) of a sulphur precursor which generates hydrogen sulfide in the flame. The gas (H2S) formed is propelled, sprayed by the flame towards the surface of the body being treated, hence the name assigned to this technology. By virtue of the strong oxidizing power of the hydrogen sulfide with regard to the metal, metal sulfides are formed. In the said method, the temperature of the surface metal, during the sulphurization, is preferably between 50°C and 500°C, more preferably between 100°C and 350°C.
US9365700 discloses an adhesive composition to be coated on steel to promote adhesion of rubber to steel during curing, the said composition comprising of an AMS (alkoxy-modified silsesquioxane) selected from the group consisting of an amino AMS, an amino/mercaptan co-AMS, an amino/blocked mercaptan co-AMS, and a weak acid-neutralized solid or aqueous solution thereof, wherein the AMS liberates about 0.05% to about 10% by weight alcohol based on the weight of the AMS when the product is treated by substantially total acid hydrolysis. The patent further discloses a method of making the said adhesive comprising the steps of (a) combining as a reaction mixture: (i) water, (ii) a solvent for water, (iii) a hydrolysis and condensation catalyst, (iv) an optional weak acid, (v) an aminotrialkoxysilane, and (vi) an optional selection from the group consisting of a mercaptoalkyltrialkoxysilane, a blocked mercaptoalkyltrialkoxysilane, and mixtures of these; (b) allowing the reaction mixture to react for about 0.5 hours to about 200 hours to form an amino alkoxysilane-modified silsesquioxane; (c) recovering the amino alkoxysilane-modified silsesquioxane from the reaction mixture; and (d) forming an adhesive solution of the amino AMS in a solvent, wherein the solution comprises about 0.01% to about 98% of the amino AMS.
US8642691 discloses a vulcanizable rubber composition comprising steel embedded therein, the composition also comprising an amino alkoxy-modified silsesquioxane (AMS) that comprises one or more compounds selected from the group consisting of an amino-AMS, an amino/mercaptan co-AMS, an amino/blocked mercaptan co-AMS, and mixtures thereof, and having the formula wherein w, x, y and z represent mole fractions, z does not equal zero, at least one of w, x or y must also be present, and w+x+y+z=1.00; wherein at least one of R1, R2, R3 and R4 must be present and selected from the group consisting of R6Z, wherein Z is selected from the group consisting of NH2, HNR7 and NR72; and the remaining R1, R2, R3 or R4 are the same or different and selected from the group consisting of (i) H or an alkyl groups having one to about 20 carbon atoms, (ii) cycloalkyl groups having 3 to about 20 carbon atoms, (iii) alkylaryl groups having 7 to about 20 carbon atoms, (iv) R6X, wherein X is selected from the group consisting of Cl, Br, SH, SaR7, NR72, OR7, CO2H, SCOR7, CO2R7, OH, olefins, epoxides, amino groups, vinyl groups, acrylates and methacrylates, wherein a=1 to about 8, and (v) R6YR8X, wherein Y is selected from the group consisting of O, S, NH and NR7; wherein R6 and R8 are selected from the group consisting of alkylene groups having one to about 20 carbon atoms, cycloalkylene groups having 3 to about 20 carbon atoms, and a single bond; and R5 and R7 are selected from the group consisting of alkyl groups having one to about 20 carbon atoms, cycloalkyl groups having 3 to about 20 carbon atoms, and alkylaryl groups having 7 to about 20 carbon atoms; wherein the amino AMS liberates about 0.05% to about 10% by weight alcohol when treated by substantially total acid hydrolysis; wherein the rubber composition is free of an effective amount to promote adhesion to steel of adhesion promoting metallic salts.
WO2020156967A1 discloses a steel cord comprising of one or more filaments comprising a steel filamentary substrate and coating that partly or totally covers the steel filamentary substrate. The coating comprises brass that consists of copper and zinc. The coating is enriched with iron. Characteristic of the coating is that the iron is present as particles in the brass, the particles having a size between 10 and 10 000 nanometer. The coating provided in the steel cord makes it rubber adherent. The steel cord disclosed by the said patent document strengthens a rubber article when it is introduced in a rubber-steel cord composite. The patent document also discloses the method to produce a filament of a steel cord as described above is presented. The method comprises the steps of:
(a) Providing an intermediate steel wire having an intermediate diameter O’: the first intermediate steel wire. The intermediate diameter is selected on the basis of the final filament diameter, the steel composition in particular the carbon content, the final tensile strength to be achieved. Typical sizes are between 0.5 and 3.2 mm;
(b) Electroplating the intermediate steel wire with copper, iron and zinc. Preferably the metals copper, iron and zinc are coated in layers;
(c) Subjecting the copper-iron-zinc coated intermediate steel wire to a heat treatment to diffuse the zinc into the copper at a temperature of at least 420°C, the melting temperature of zinc. The formation of iron-zinc zeta-^) phase is avoided if the temperature is kept below 530°C: the iron will not melt and there is no formation of iron-zinc alloy. The temperature must be held for at least 2 seconds in order to enable the zinc to diffuse into the copper, within 10 seconds the diffusion is sufficient. The resulting wire is an intermediate steel wire with a brass coating enriched with iron particles;
(d) Optionally the zinc oxide and iron oxide are removed from the surface of the intermediate steel wire with a brass coating enriched with iron particles. By preference this is done in an acid bath.
US4182639 discloses a method for improving the adhesion of brass-coated steel cord to rubber. The invention employs inorganic or organic phosphates, preferably tricresylphosphate, and various sulphur-containing rubber vulcanization accelerating agents. The accelerators interact with ZnO to form complexed zinc perthiomercaptides, and the perthiomercaptide is believed to be the active sulphurating agent that reacts with and bonds to the rubber hydrocarbon. The surface of a typical 70/30 brass (70% copper, 30% zinc) contains ZnO, and after the reaction of accelerator and ZnO is completed, the remaining active copper sites on the brass are covered or rendered inert by treatment with corrosion inhibitors or other such treatment. As a result of such treatments, the brass surface then contains the proper number of reactive polysulfide pendant groups, which are free to interact with and bond to the rubber compound. The number of reactive polysulfide pendant groups on the brass surface controls the extent of the interaction of the cord with the rubber because none or relatively few copper sites remain active on the cord.
The research article published in the Journal ACS Applied Materials and Interfaces on “Organo-Chlorinated thin films deposited by atmospheric pressure plasma-enhanced chemical vapour deposition for adhesion enhancement between rubber and zinc-plated steel monofilaments (ACS Applied Materials and Interfaces, 2015, 7, 26, 14317-14327)” discloses a method of adhesion interface established between the rubber and the zinc –plated steel monofilament pretreated by Ar/O2 plasma and coated with a 75 nm thick organo-chlorinated thin film.
All the above cited prior art documents disclose complex processes for reinforcement of BCSC which either involve high temperature or successive heat treatment or involve use of multiple organic compounds. They also involve the formation of metal sulfides or addition of sulphur content in the rubber composition for covering steel cords and operate at high temperatures. The conventional methods also require more time for vulcanization and need higher sulphur content. Further, the methods that operate at a surface temperature of BCSC (between 100 to 350°C) incur an additional manufacturing cost and free radicals produced by the sulphur donating precursors pose a serious trouble in commercialising the said methodology. Therefore there is a need in the art to provide a method for improving the brass-rubber interfacial adhesion through an economically viable and environmentally friendly process.
OBJECTIVES OF THE INVENTION
The principal objective of the present invention is to provide a method of synthesis of copper sulfide nanostructures (CuxS, where x varies from 1-2) on brass-coated steel cords (BCSC), the said synthesis being possible even at room temperature (ambient conditions), to improve the brass-rubber interfacial adhesion.
Another objective of the present invention is to provide a method of synthesis of copper sulfide nanostructures (CuxS, where x varies from 1-2) on brass-coated steel cords (BCSC) which has the added advantage of reduction in vulcanization time.
Yet another objective of the present invention is to provide an economical method of synthesis of copper sulfide nanostructures (CuxS) on brass-coated steel cords (BCSC).
Still another objective of the present invention is to provide an environmental friendly method of synthesis of copper sulfide nanostructures (CuxS) on brass-coated steel cords (BCSC).
Yet another objective of the present invention is to provide an apparatus for enabling the synthesis of copper sulfide nanostructures (CuxS) on brass-coated steel cords (BCSC) in order to achieve the aforesaid objectives.
SUMMARY OF THE INVENTION
The present invention discloses a method of synthesizing a chemical compound of formula CuxS, where x varies from 1-2 through electrospray treatment of elemental sulphur (S) on Brass-Coated Steel Cords (BCSC) at a temperature between room temperature and 1100˚C, the said method comprising the steps of:
i) placing a platinum wire each inside a plurality of glass capillaries and placing BCSC below the said plurality of glass capillaries, at a distance of 1-5 cm, wherein the said set-up is at a temperature between room temperature and 1100˚C;
ii) refluxing 10-50 mg of a sulphur precursor in 10-100 mL of an organic solvent at 120˚C for 10 hours followed by purging the solution obtained with an inert gas or nitrogen to obtain a precursor solution of sulphur;
iii) transferring the said precursor solution of sulphur into the said plurality of glass capillaries using a micropipette;
iv) performing electrospray treatment for about 25-30 minutes by applying high voltage to the platinum wire and grounding the BCSC through a motor while simultaneously rotating the BCSC, whereby a spray plume is generated from the tip of the glass capillaries consisting of S2- ions which react with the copper from the BCSC to form mixture of CuxS which is uniformly distributed on the said BCSC, wherein x ranges from 1 - 2; and,
v) storing the electrosprayed BCSC in vacuum or nitrogen environment before vulcanising with rubber compound.
The present invention further discloses an apparatus (100) for synthesising a chemical compound of formula CuxS through the aforementioned method wherein the said apparatus (100) comprises of:
i) a plurality of glass capillaries (101a, 101b, 101c), wherein each of the said glass capillaries (101a, 101b, 101c) consist of a platinum wire (102a, 102b, 102c) placed inside;
ii) a Brass-Coated Steel Cords (BCSC) (103) positioned below the said glass capillaries at a distance of 1-5 cm, the said BCSC (103) being connected to a motor (104), the said motor facilitating the constant rotation of the said BCSC.
BRIEF DESCRIPTION OF THE DIAGRAMS
Figure 1(A) is a schematic representation of the apparatus (100) for synthesising a chemical compound of formula CuxS through the method disclosed by the present invention
Figure 1(B) illustrates copper sulfide nanostructure formation on brass coated steel cord with increase in electrospray time. The nanostructures evolve into fully grown structures as a function of time.
Figure 2(A) and (B) represent Scanning Electron Microscope (SEM) images of the copper sulfide nanostructures on BCSC grown by the electrospray method.
Figure 2(C) represents Energy Dispersive X-ray Spectra (EDX) spectra indicating the formation of copper sulphide nanostructures
Figure 3 illustrates the nanostructure thickness and morphology wherein (A), (B) and (C) represent bright-field TEM images of the nanostructures formed on brass grid, (D) represents HRTEM showing crystalline nature of the nanostructures. The lattice fringes marked in the images correspond to that of copper sulfide nanostructures (E), (F) and G represent the SEM images of the nanostructures, respectively. The TEM and SEM images imply the dendritic morphology for the copper sulfide nanostructures.
Figure 4 represents concentration-dependent nanostructure growth at concentration of sulphur solution at (A) 5mM, (B) 10mM, (C) 15mM, (D) 20mM, respectively and (E) represents the rubber coverage over brass-coated steel cord and (F) shows the pull out force (POF) at different sulphur concentrations.
Figure 5 represents time dependent nanostructure growth at electrospray time of (A) 10 minutes, (B) 15 minutes, (C) 20 minutes, (D) 25 minutes and (E) represents rubber coverage over brass-coated steel cord and (F) shows the pull out force at different time periods.
Figure 6 shows X-ray diffraction data of electrospray-assisted synthesis vs. control after vulcanization with rubber compound. While the conventional control experiment produced a mixture of Copper and Zinc sulfides, the current methodology (electrospray-assisted) produced only copper sulfides (CuxS where x varies from 1-2).
DETAILED DESCRIPTION OF THE INVENTION
The present invention as embodied by “Novel Synthesis of Copper Sulfide Nanostructures in Brass Coated Steel Cords Used in Radial Tires under Ambient Conditions”, succinctly fulfils the above-mentioned need(s) in the art. The present invention has objective(s) arising as a result of the above-mentioned need(s), said objective(s) being enumerated below. In as much as the objective(s) of the present invention are enumerated, it will be obvious to a person skilled in the art that the enumerated objective(s) are not exhaustive of the present invention in its entirety, and are enclosed solely for the purpose of illustration. Further, the present invention encloses within its scope and purview, any structural alternative(s) and/or any functional equivalent(s) even though such structural alternative(s) and/or any functional equivalent(s) are not mentioned explicitly herein or elsewhere, in the present disclosure. The present invention therefore encompasses also, any improvisation(s)/modification(s) applied to the structural alternative(s)/functional alternative(s) within its scope and purview. The present invention may be embodied in other specific form(s) without departing from the spirit or essential attributes thereof.
Throughout this specification, the use of the word "comprise" and variations such as "comprises" and "comprising" may imply the inclusion of an element or elements not specifically recited.
The invention disclosed by the present specification relates to the selective synthesis of CuxS by electrospray of elemental sulphur (S) on brass-coated steel cords (BCSC) which is possible even at room temperature and utilization of such modified steel cords in the tire industry. Electrospray is a method well known in the field of mass spectrometry that is essentially used to create an aerosol from a liquid. A sulphur precursor in this present invention is capable of generating S2- ions during the electrospray treatment. The precursor can be sulphur or sulphur containing organic or inorganic material that is dissolved in an organic solvent. Copper sulfides here is symbolically represented as CuxS, where x varies from 1-2. The synthesized copper sulfide on BCSC is in the unfinished manufacturing stage and has to be incorporated into a rubber matrix. The prepared rubber samples showed 9% enhanced POF attributed to the selective synthesis of Copper Sulfide nanostructures through the electrospray droplet synthesis. The method and apparatus thereof disclosed by the present invention not only has the technical advancement of formation of Copper Sulfide nanostructures at room temperature i.e. ambient conditions, but also provides other advantages such as reduction in use of sulphur, reduction in vulcanization time and improvement in interfacial adhesion.
In the present invention, an interface comprising of copper sulfides is created ex-situ by electrospray of sulphur solution on BCSC. The sulphur solution is prepared by refluxing sulphur powder weighing 10-50 mg in 10-100 mL of an organic solvent at 120˚C for 10 hours followed by purging the solution obtained with an gas or nitrogen, wherein the organic solvent is selected from a group comprising of toluene, hexane, methanol, ethanol, benzene, carbon disulfide, or a combination of the aforementioned solvents at specified ratios or any other solvent wherein the sulphur precursor can be dissolved / dispersed. The concentration of the sulphur solution can be anywhere between one nanomolar to 1000 millimolar concentration.
The apparatus (100) disclosed by the present invention comprises of:
i) a plurality of glass capillaries (101a, 101b, 101c), wherein each of the said glass capillaries (101a, 101b, 101c) consist of a platinum wire (102a, 102b, 102c) placed inside;
ii) a Brass-Coated Steel Cord (BCSC) (103) positioned below the said glass capillaries at a distance of 1-5 cm, the said BCSC (103) being connected to a motor (104), the said motor facilitating the constant rotation of the said BCSC.
The sulphur precursor solution is transferred into the plurality of glass capillaries (101a, 101b, 101c) using a 10 µL micropipette. The glass capillary (inner diameter of 20 to 25 mm) is used for the electrospray. The capillary is made by pulling a borosilicate glass capillary using a micropipette puller (Sutter instruments, USA). A platinum wire is placed inside the glass capillary and the BCSC is placed below the capillary at a distance of 1-5 cm. Synthesis of copper sulfide nanostructures on BCSC was carried out using an electrospray setup as characterized by the apparatus (100) which is illustrated by Figure 1(A). High voltage is applied to the platinum wire and BCSC is grounded through a DC motor. The whole setup is placed at a temperature between room temperature and 1100˚C. A spray plume is generated from the tip of glass capillary consisting of S2- ions. Electrospray time is controlled between 25-30 minutes. Copper (from BCSC) reacts with S2- to form copper sulfide. BCSC is constantly rotated during the spray to ensure uniform distribution of the copper sulfide nanostructures. During the spray, visual colour change was noted on the surface of BCSC indicating the formation of copper sulfide.
Finally, the electrosprayed BCSC obtained from the above method is stored in vacuum or a nitrogen environment before vulcanizing with rubber compound in order to prevent oxidation of the synthesized nanostructure. The said rubber compound is a mixture of natural rubber, synthetic rubbers, fillers such as carbon black and silica, vulcanization activators, accelerators, promoters, already known to a person skilled in the art.
The copper sulfide nanostructures (CuxS, where x varies from 1-2) formed from the above elucidated electrospray treatment on BCSC using sulphur have an increased ability to adhere with rubber mixture during vulcanization. Scanning electron microscopy (SEM) measurement was performed on the electrosprayed BCSC to observe the morphology of copper sulfide nanostructures. The SEM results are characterized by Figures 2(A) and (B).
Energy-dispersive X-ray spectroscopy (EDX spectra) and elemental composition of the copper sulfide nanostructures were also analyzed, the result of which is characterized by Figure 2(C).
Table 1: Elemental composition of the copper sulfide nanostructures
Element Wt % At%
SK 06.19 10.70
FeK 64.03 63.58
CuK 18.66 16.28
ZnK 11.12 09.43
Matrix Correction ZAF

Figure 2(C) represents Energy Dispersive X-ray Spectra (EDX) spectra and elemental composition of the copper sulfide nanostructures (Table 1) on BCSC after the electrospray experiment. The EDS data indicate that the formed sulfide nanostructures are of Cu, and S. The element iron (Fe) and Zinc (Zn) are detected from the BCSC.
The copper sulfides formed were further characterized by TEM, SEM, and XRD respectively (Figure 3, and 6).
The metal sulfide nanostructures on BCSC generated with the help of the present invention promote interfacial bonding between rubber and steel. Further, the interfacial nanostructures formed through the electrospray route enhance the un-aged and aged pull out force between rubber and steel owing to the optimum thickness and morphology of the nanostructures.

Table 2 shows POF measurement of electrosprayed BCSC and unreacted BCSC.
S.no Control (KgF) Rating Electrosprayed BCSC (KgF) Rating
1 173.0 4.5 181.3 4.5
2 142.1 4 175.5 4.5
3 182.8 4.5 179.2 4.5
4 181.5 4.5 160.5 4.0
5 133.7 4 172.3 4.5
6 159.6 4 185.4 4.5
7 149.8 4 168.9 4.5
8 160.2 4 183.2 4.5
9 183.2 4.5 176.2 4.5
Average 162.8 4.2 175.8 4.4
Further, the metal sulfide nanostructures formed as a result of electrospray will have significant advantages by reduction of vulcanization time and lower sulphur concentration in radial tires.
Further, the electrospray mediated copper sulfide nanostructures formation on BCSC when incorporated into the rubber matrix reduces the manufacturing cost of a radial tire by 3% owing to reduced amount of sulphur and vulcanization time and also improves tire life.
The invention disclosed herein is for the synthesis of copper sulfide nanostructures on steel cords which are coated with brass – an alloy of copper and zinc. It will be apparent to a person skilled in the art that the method and apparatus disclosed by the instant invention can be similarly applied for synthesizing sulfides of metals such as iron, manganese, cobalt, nickel, chromium, and their associated alloy systems coated on steel cords, and such synthesis will be within the spirit and scope of the instant invention.

It will be apparent to a person skilled in the art that the above description is for illustrative purposes only and should not be considered as limiting. Various modifications, additions, alterations, and improvements without deviating from the spirit and the scope of the invention may be made by a person skilled in the art.

Kalyan Jhabakh
(Agent for Applicant)
IN/PA-830