FORM 2
THE PATENTS ACT, 1970
(39 of 1970) & The Patents Rules, 2003
COMPLETE SPECIFICATION
(See section 10 and rule 13)
1. TITLE OF THE INVENTION
Adhesive used for Gluing Film of Metal to Metal for Industrial Applications
2. APPUCANT(S)
a) NAME: HINDUSTAN AERONAUTICS LIMITED
b) NATIONALITY: INDIAN
c) ADDRESS: Chief Manager(Design) & IPR Officer, Aircraft Upgrade Research & Design Centre, (AURDC) Hindustan Aeronautics Limited, P.O Ojhar Township, Nasik, Maharashtra, PIN: 422207, INDIA
3. PREAMBLE TO THE DESCRIPTION
PROVISIONAL The following COMPLETE The following specification
specification describes the particularly describes the invention and
invention. the manner in which is to be performed.
√
4. DESCRIPTION (Description shall start from next stage.)
Refer Annexure ll
5- CLAIMS (Not applicable for provisional specification. Claims should start with the preamble - "I/We claim" on separate page)
Refer Annexure II
6. DATE AND SIGNATURE (to be given at the end of last page of specification)
7. ABSTRACT OF THE INVENTION (to be given along with complete specification on separate page)
Refer Annexure III

1 Title of the Invention
Adhesive used for gluing film of metal to metal for Industrial applications
2 Field of the Invention
The invention relates to chemical engineering process in general and adhesive composition in particular to phenolic nitrile based adhesives for use in industry, typically in aerospace industry.
3 Background of the Invention
In aircraft, for bonding of vulcanized nitrile base rubber to metallic parts, in different media and climatic conditions, adhesive is used. During overhaul of an aircraft, adhesive is used for gluing metallic materials as per technology. Hence there is a need to develop adhesive for bonding metal parts as per aerospace standard, meeting aircraft requirement.
3.1 Prior Art
Imported adhesive was used for gluing film of metal to metal for Industrial applications. This imported adhesive was not readily available and cost was ~ high. Hence the present invention to develop phenolic nitrile based adhesive was taken up.
No such specific adhesive was available in the market. Hence there was need to develop appropriate adhesive indigenously addressing the issues being faced for gluing film of metal to metal, working at -20°C to 80°C temperature in different media and climatic conditions.
4 Brief Summary of the Invention
The present invention relates to develop phenolic nitrile based Indigenous adhesive used for gluing film of metal to metal, working at -20°C to 80°C temperature in different media and climatic conditions.

The present invention provides adhesive composition and formulation for manufacturing of the invented adhesive which is used in aircraft application.
The adhesive composition contains the following ingredients:-
Nitriie based Rubber Solution (Component A):
- Polymer Acrylonitrile Butadiene is used as base polymer;
- Accelerator modifier - Zinc Oxide and Zinc diethyldithiocarbamate are used to increase vulcanization rate by activating the accelerators;
- Butyl acetate and Ethyl Acetate are used as esters for the preparation of
rubber solution and maintain required viscosity of adhesive;
- N-2 (aminoethyl) - 3 -aminopropyltrimethoxy silicone is used as coupling
agent;
Phenolic Resin (Component B):
- Phenolic resin and ester Butyl acetate is used as component B; Vulcanising Agent (Component C):
- Sulphur powder is used as component C for manufacturing of Indigenous
adhesive
B. Process
Phenolic nitrile based adhesive is manufactured using following ingredients:

Table -1

SI. No. Ingredient Nomenclature Qty. parts
by weight
in%
Nitrile based Rubber Solution (Component A)
1 Polymer Acrylonitrile Butadiene 8.4-12.5
2 Zinc Oxide 0.4 - 0.6
3 Zinc diethyldithiocarbamate 0.1 -0.2
4 Butyl acetate 20.9-31.3
5 Ethyl Acetate 20.9-31.3
6 N-2 (aminoethyl)- 3 aminopropyltrimethoxy silicone 0.1 -0.2
Phenolic Resin (Component B)
7 Phenolic resin 11.2-16.8
8 Butyl acetate 17.9-26.9
Vulcanising Agent (Component C)
9 Sulphur powder 4.1 - 0.2
i) Component A, component B & component C of Phenolic nitrile based adhesive is manufactured by mixing the ingredients mentioned in the Table 1
a) Component A is manufactured as

- Component A is manufactured by masticating polymer Nitrile base rubber, zinc oxide and Zinc diethyldithiocarbamate on two roll mill machine;
- The above masticated polymer is mixed with esters i.e. Butyl acetate and Ethyl Acetate by constantly stirring the mixture in mixer; add N-2 (aminoethyl)- 3 -aminopropyltrimethoxy silicone in the mixture till homogeneity;
- Component B is manufactured by making the solution of resin in butyl acetate by constantly stirring the mixture in mixer;
- Component C is Sulphur powder.

b) Component A, component B and component C are stored separately.
c) Component A (Nitrile based Rubber Solution) : Component B (Phenolic Resin) : Component C (vulcanizing agent) separately are mixed in the definite ratio, i.e. 50 to 90 : 35 to 45 : 0.11 for manufacturing adhesive at the time of use. After manufacturing the adhesive, it was evaluated by testing for physico-mechanical properties as per aircraft requirement. Adhesive had been tested for Appearance, concentration in %, Viscosity, base material (separately for Component A & B), purity of sulphur. After these testing, component A: Component B: component C are mixed in the definite ratio for manufacturing of the adhesive. Adhesive tested for shear strength of glued joints between metal to metal materials and found satisfactory to meet the requirements of aircraft.

Title: ADHESIVE USED FOR GLUING FILM OF METAL TO METAL FOR INDUSTRIAL APPLICATIONS
We Claim:
1. An adhesive used for gluing film of metal to metal for Industrial
applications comprising:
- A Nitrile based Rubber Solution;
- A Phenolic Resin; and
- A vulcanising agent typically Sulphur.
2. The adhesive as claimed in Claim 1, wherein the Nitrile based Rubber
Solution further comprises Acrylonitrile base polymer, accelerator and
activator, and mixture of esters and coupling agent.
3. The adhesive as claimed in Claim 1, wherein the Phenolic Resin further
comprises Phenolic resin and ester.
4. The adhesive as claimed in Claim 1, wherein the Nitrile based Rubber
Solution is manufactured using
a. A base-polymer, particularly in this-case; Polymer Acrylonitrile
Butadiene, typically acrylonitrile 41-42 % (8.4 % to 12.5 percent of total weight of final mixture) and Zinc Oxide (0.4 % to 0.6 percent of total weight of final mixture) masticated thoroughly in two roll mill and
b. zinc diethyldithiocarbamate (0.1 % to 0.2 percent of total weight
of final mixture) is added further and masticated in two roll mill
c. Above masticated polymer is mixed with solvents i.e. Butyl
acetate (20.9 to 31.3 percent of total weight of final mixture) and
Ethyl Acetate (20.9 to 31.3 percent of total weight of final mixture)

by constantly stirring the mixture in mixer; add [N-2 (Aminoethyl)-3 -Aminopropyltrimethoxy Silicone 0.1 to 0.2 percent of total weight of final mixture)] in the mixture till homogeneity.
5. The adhesive as claimed in Claim 1, wherein the Phenolic Resin is manufactured by making the solution of phenolic resin (11.2 to 16.8 percent of total weight of final mixture) in solvent butyl acetate (17.9 to 26.9 percent of total weight of final mixture) by constantly stirring the mixture in mixer
6. The adhesive as claimed in Claim 1, wherein the Nitrile based Rubber Solution, the Phenolic Resin and Sulphur are mixed in the ratio of 90:45:0.11