Title of Invention

A PROCESS FOR COATING OF ROOFING BOLTS WITH ZINC PHOSPHATE AND LOW DENSITY POLYETHYLENE FOR BETTER RUST PREVENTION AND IMPROVING MECHANICAL PROPERTIES OF COATING

Abstract A process for coating of roofing bolts with zinc phosphate and low density polyethylene for better rust prevention and improving mechanical properties of coating like abrasion resistance, peel off force and malleability of the coat, comprising dipping the bolts into zinc phosphate solution which is heated between 80 to 85 °C for achieving uniform zinc phosphate coating, the said bolts with uniform coat of zinc phosphate, are further heated in an oven to a temperature between 325 to 350 °C which is critically maintained with the help of specially designed thermister control and after attaining the desired temperature, keeping these bolts at attained temperature for about 30 minutes and then the virgin polymer powder like low density polyethylene, specially ground to 65 micron mesh is sprayed upon the body of the bolts with the help of specially designed spray gun to get the desired uniform fusion coating of minimum 0.5 mm thickness of the said polymer powder.
Full Text FORM 2
THE PATENTS ACT, 1970 (39 of 1970)
COMPLETE SPECIFICATION
(Section 10)
'A PROCESS FOR COATING OF ROOFING BOLTS WITH ZINC PHOSPHATE AND LOW DENSITY POLYETHYLENE FOR BETTER RUST PREVENTION AND IMPROVING MECHANICAL PROPERTIES OF COATING'
JAIPRAKASH ANANT SATHE,
1187/25, Ghole Road,
Shivajinagar,
PUNE-411005. Maharashtra State, India
Indian National
GRANTED
26-8-2004
The following specification describes the nature of this invention and the manner
ORIGINAL
820/MUMNP/2000

A process for coating roofing bolts with zinc phosphate for better rust prevention and improving their mechanical properties.
Present invention relates to a process for coating roofing bolts with zinc phosphate for better rust prevention and improving their mechanical properties prior to the process of Polymer coating, instead of galvanizing for bettering rust prevention with increased essential mechanical properties. These types of coating are most stable and achieve more uniformity and thus better results.
The normal galvanizing roofing, bolts and accessories like bitumen washer, G.I washer are subject to, leakage and corrosion under adverse working conditions. To achieve better anti-corrosive properties, polymer coating of galvanized bolts was one of the methods in practice. However, it has been revealed over a period of time that there are limitations of polymer coated galvanized bolts under severe, adverse conditions. Hence, such types of bolts have proved not useful in case of critical processes and plants.
The disadvantages of polycoated galvanized bolts and accessories are as under:-
1. Improper fusion process adopted by manufacturers leads to failure in achieving good bondage thereby leading to corrosion under adverse condition.
2. If a heavy / thick coat of polymer is given, same results in cracking of coats, ultimately leading to corrosion.
3. Improper fusion process adopted by manufacturers results in poor abrasion resistance and it leads to peeling off the polymer coat.
Thus, the object of the present invention aims at coating the bolts and accessories with zinc phosphate instead of galvanizing before polymer coating for improved rust prevention and mechanical properties.


It is also the object of the present invention to increase the shelf life of the bolts by uniform coating of zinc phosphate and polymer coat.
The bolts are manufactured from black rolled bar. This black rolled bar is cut to required size and then thread-rolled. These bolts are stronger in constitution due to reforming the material instead of removal as in case of thread cutting. These bars are then bent to required sizes and shapes to form the desired hooks/bolts of desired dimensions. Such hooks / bolts are then coated after galvanizing, as is the normal practice.
Therefore, according to this invention, we found that a process of zinc phosphating the roofing bolts instead of galvanizing, before coating of low density polyethylene, results in and improving mechanical properties of coating like abrasion resistance, peel off force and malleability of the coat, as the low density polyethylene coating achieved after the zinc phosphating is most stable, equally corrosion resistant (like galvanizing.). The molecular structure of zinc phosphate coat is such that it absorbs and retains rust-preventing compound in the micro porous structure such as the virgin polymer powder and non-phenolic oils, better that the untreated steel/galvanized steel.
According to this invention, therefore, a process for coating of roofing bolts with zinc phosphate and low density polyethylene for better rust prevention and improving mechanical properties of coating like abrasion resistance, peel off force and malleability of the coat, comprises dipping the bolts into zinc phosphate solution, which is heated between 80°C to 85°C for achieving uniform zinc phosphate coating, the said bolts with uniform coat of zinc phosphate, are further heated in an oven to a temperature between 325°C to 350°c which is critically maintained with the help of specially designed thermister control, and after attaining the desired temperature, keeping these bolts at attained temperature for about 30 minutes and then the virgin polymer powder like low density polyethylene, specially ground to 65 micron mesh is sprayed upon the body of the bolts with the help of specially designed spray gun to get the desired uniform fusion coating of minimum 0.5 mm thickness of the said polymer powder.


to get the desired uniform fusion coating of minimum 0.5 mm thickness of the said polymer powder.
The following results have been obtained by this process :-
• Coating Thickness 05mm min.
• Temperature Resistivity 60°C max.
• Inert to Normal Acid & Alkaline fumes at
70°C. Salt Water, Sultry weather, at 95%RH.at 35°C.
• Abrasion Resistance Suitable to resist Purlin movements due
to Wind Pressure.
Following advantages have been achieved by this invention :-
1. Uniform and stable coating resulting in better performance in adverse condition.
2. Very high abrasion resistance and peel off resistance due to strong bondage of polymer coat.
3. Malleability present on the coat which is absent in galvanized polycoated bolts.
4. Can be widely used, as inert to acid and alkaline fumes at 70°C.
5. Long shelf life.


WE CLAIM:
1.. A process for coating of roofing bolts with zinc phosphate and low density polyethylene for better rust prevention and improving mechanical properties of coating like abrasion resistance, peel off force and malleability of the coat, comprising dipping the bolts into zinc phosphate solution which is heated between 80 to 85 °C for achieving uniform zinc phosphate coating, the said bolts with uniform coat of zinc phosphate, are further heated in an oven to a temperature between 325 to 350 °C which is critically maintained with the help of specially designed thermister control and after attaining the desired temperature, keeping these bolts at attained temperature for about 30 minutes and then the virgin polymer powder like low density polyethylene, specially ground to 65 micron mesh is sprayed upon the body of the bolts with the help of specially designed spray gun to get the desired uniform fusion coating of minimum 0.5 mm thickness of the said polymer powder.
Dated this 10th Day of August, 2000
(M.S. KHADILKAR) Agent For Applicant

Documents:

820-MUM-2000-ABSTRACT(8-9-2000).pdf

820-MUM-2000-ABSTRACT(GRANTED)-(12-1-2007).pdf

820-mum-2000-cancelled pages(26-08-2004).pdf

820-MUM-2000-CANCELLED PAGES(26-8-2004).pdf

820-MUM-2000-CLAIMS(COMPLETE)-(8-9-2000).pdf

820-mum-2000-claims(granted)-(08-09-2000).doc

820-mum-2000-claims(granted)-(08-09-2000).pdf

820-MUM-2000-CLAIMS(GRANTED)-(12-1-2007).pdf

820-mum-2000-correspondence(12-01-2007).pdf

820-MUM-2000-CORRESPONDENCE(17-3-2005).pdf

820-MUM-2000-CORRESPONDENCE(18-3-2005).pdf

820-MUM-2000-CORRESPONDENCE(26-8-2004).pdf

820-MUM-2000-CORRESPONDENCE(IPO)-(16-3-2007).pdf

820-mum-2000-correspondence(ipo)-(28-10-2005).pdf

820-MUM-2000-DESCRIPTION(COMPLETE)-(8-9-2000).pdf

820-MUM-2000-DESCRIPTION(GRANTED)-(12-1-2007).pdf

820-mum-2000-form 1(08-09-2000).pdf

820-MUM-2000-FORM 1(8-9-2000).pdf

820-mum-2000-form 19(07-06-2003).pdf

820-mum-2000-form 19(23-06-2003).pdf

820-MUM-2000-FORM 19(23-6-2003).pdf

820-MUM-2000-FORM 2(COMPLETE)-(8-9-2000).pdf

820-mum-2000-form 2(granted)-(08-09-2000).doc

820-mum-2000-form 2(granted)-(08-09-2000).pdf

820-MUM-2000-FORM 2(GRANTED)-(12-1-2007).pdf

820-MUM-2000-FORM 2(TITLE PAGE)-(COMPLETE)-(8-9-2000).pdf

820-MUM-2000-FORM 2(TITLE PAGE)-(GRANTED)-(12-1-2007).pdf

820-mum-2000-form 3(23-08-2001).pdf

820-MUM-2000-FORM 3(23-8-2001).pdf

820-MUM-2000-FORM 3(5-9-2001).pdf

820-mum-2000-power of attorney(29-03-2004).pdf

820-MUM-2000-POWER OF AUTHORITY(29-3-2004).pdf

820-MUM-2000-POWER OF AUTHORITY(8-9-2000).pdf

820-MUM-2000-SPECIFICATION(AMENDED)-(26-8-2004).pdf

820-MUM-2000-SPECIFICATION(AMENDED)-(29-3-2004).pdf

820-MUM-2000-SPECIFICATION(AMENDED)-(6-8-2004).pdf


Patent Number 204161
Indian Patent Application Number 820/MUM/2000
PG Journal Number 23/2007
Publication Date 08-Jun-2007
Grant Date 12-Jan-2007
Date of Filing 08-Sep-2000
Name of Patentee JAIPRAKASH ANANT SATHE
Applicant Address 1187/25, GHOLE ROAD, SHIVAJINAGAR, PUNE - 411 005, MAHARASHTRA STATE, INDIA.
Inventors:
# Inventor's Name Inventor's Address
1 JAIPRAKASH ANANT SATHE 1187 / 25, GHOLE ROAD, SHIVAJINAGAR, PUNE - 411 005. MAHARASHTRA STATE, INDIA.
PCT International Classification Number E21 D/21/00
PCT International Application Number N/A
PCT International Filing date
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 NA