FORM 2
THE PATENTS ACT, 1970
(39 of 1970)
&
THE PATENTS RULES, 2003
Complete Specification
[See section 10, Rule 13]
TITLE
ALUMINIUM REFLECTOR LAMINATE
APPLICANT
Hindalco Industries Limited
Of Address
Ahura Centre,1st Floor, B-Wing, Mahakali Caves Road,
Andheri (East), Mumbai - 400 093
COMPLETE SPECIFICATION
The following specification particularly describes this invention and the manner in which it is
to be performed

FIELD OF THE INVENTION
The present invention relates to an aluminium laminate and its method of manufacturing. The invention also relates to a reflector comprising an aluminium laminate.
BACKGROUND OF THE INVENTION
Aluminium metal has high reflectivity for Ultra-Violet (UV) rays in the wavelength range of 250 nm to 400 nm. Several products have been developed 10 having high reflectivity for solar and lighting applications. These applications generally require high purity aluminium alloys and are therefore not manufactured from recycled aluminium.
High reflectivity of aluminium sheets can also be achieved by either sputtering silver on the sheets or by chemical or electro-chemical surface treatment of the sheets. However, the results for reflectivity are not uniform, and the process is cost intensive.
ES 2210164 describes an aluminium reflector containing a protective layer of a sol-gel varnish which is located on the outside and is resistant to weathering.
DE 29812559 describes a composite material, in particular for reflectors, with a carrier made of aluminium, with an intermediate layer on the carrier and with an optically effective multilayer system applied to the intermediate layer, which consists of three layers, the two upper layers being dielectric layers and the lowermost layer is a metallic layer applied to the intermediate layer. The optical multilayer system is coated with a protective coating which comprises a layer protective sol-gel varnish located in the exterior.

US 20190076897 describes a foil product having high reflectivity in UV-C wavelength. This document describes an aluminium foil having a ratio of a total surface area of aluminium particles pressed into or adhered to a region of a predetermined surface area relative to the surface area of the region, to be 0.05% or less. The total surface area of crystallized materials present in the region relative to the surface area of the region is 2% or less. The average surface area per one crystallized material is 2 μm2 or less. The examples show that this requires high of purity aluminium which requires virgin aluminium and is not amenable to recycling. Electro¬chemical treatment is also described to enhance the reflectivity of the foil made from direct chill casting technique.
US 20180274072 relates to a method of metal casting comprising melting recycled aluminium into liquid metal then adding alloying element comprising magnesium, silicon, or copper to the liquid metal to form a modified liquid metal. The modified liquid metal is then casted and rolled into a metal product.
SUMMARY OF THE INVENTION
The subject matter described herein relates to an aluminium based laminate.
One of the objectives of the present invention, therefore, is to provide a reflective laminate for solar and lighting applications using recyclable Aluminium alloys.
The laminate of the present disclosure comprises a core layer having a first and second surface, said second surface adhesively bonded with a layer of aluminium foil.

These and other features, aspects, and advantages of the present subject matter will become better understood with reference to the following description.
BRIEF DESCRIPTION OF THE DRAWINGS
The foregoing summary, as well as the following detailed description of the invention will be better understood when read in conjunction with the appended drawings. For the purpose of assisting in the explanation of the invention, there are shown in the drawings embodiments which are presently preferred and considered illustrative. It should be understood, however, that the invention is not limited to the precise arrangements and instrumentalities shown therein. In the drawings:
Figure 1 is a schematic representation of cross-sectional view of the reflective laminate of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
In describing and claiming the invention, the following terminology will be used in accordance with the definitions set forth below. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Although any methods and materials similar or equivalent to those described herein can be used in the practice or testing of the present invention, the preferred methods and materials are described herein. As used herein, each of the following terms has the meaning associated with it in this section. Specific and preferred values listed below for individual process parameters, substituents, and ranges are for illustration only; they do not exclude other defined values or other values falling within the preferred defined ranges.

As used herein, the singular forms "a," "an," and "the" include plural reference unless the context clearly dictates otherwise.
The terms “preferred” and “preferably” refer to embodiments of the invention that may afford certain benefits, under certain circumstances. However, other embodiments may also be preferred, under the same or other circumstances. Furthermore, the recitation of one or more preferred embodiments does not imply that other embodiments are not useful, and is not intended to exclude other embodiments from the scope of the invention
As used herein, the terms “comprising” “including,” “having,” “containing,” “involving,” and the like are to be understood to be open-ended, i.e. to mean including but not limited to.
As used herein, the term “laminate” refers to an article that is made by sticking together two or more layers of a particular material.
Referring to figure 1, in an aspect of the present invention provides an aluminium laminate comprising,
(i) at least one core layer having recyclable aluminium alloy selected from AA3xxx, AA4xxx, or AA8xxx series such as AA3105, AA4015, or AA8011,
(b) at least one reflective layer comprising of an aluminium foil comprising of an alloy composition selected from AA1xxx or AA8xxx series such as AA1050, AA1235 or AA8011; and
(c) a layer of adhesive, bonding said core layer and reflective layer.

In an embodiment, a reflector comprising at least one aluminium laminate having a core layer and an aluminium foil is disclosed. The core layer and aluminium foil are bonded to each other. The core layer has recyclable aluminium alloy selected from AA3xxx, AA4xxx, or AA8xxx series such as AA3105, AA4015, or AA8011 and the aluminium foil comprises of alloy composition selected from AA1xxx or 30 AA8xxx series such as AA1050, AA1235 or AA8011.
The core layer is produced by melting a charge of various grades of aluminium alloys to make a highly recycled content aluminium alloy like AA3105, AA4015, or AA8011. The alloy is cast either by direct chill casting process or by continuous casting process followed by hot and cold rolling.
Intermediate annealing treatments may optionally be employed to improve the rollability. The core layer has a thickness in a range of 0.2-3.0 mm.
The aluminium foil of reflective layer is produced by direct chill casting process or by continuous casting process followed by hot and cold rolling to a foil of thickness of more than 6 microns and less than 50 microns. During rolling, the reduction in thickness in each pass is in a range of 30-65%. The work rolls have a roughness in a range of 0.1-0.2 micron.
The laminate comprises at least 50% of recycled aluminium alloy and has a surface roughness of less than 0.2 micron. The laminate has a reflectivity of greater than 80% in the UV-C wavelength range (100-280 nm).

The core layer and aluminium foil of the laminate is rolled individually to achieve the characteristics of recyclability and high reflectivity. The laminate comprising recycled aluminium does not require any chemical or electro-chemical surface treatments for improving the reflectivity. This makes the laminate cost-effective. The laminate is also recyclable thereby making it environment friendly and economic.
Another aspect of the present invention relates to a method of manufacturing an aluminium laminate. The method comprises the step of bonding the core layer and aluminium foil by an adhesive, roll bonding or lamination techniques.
Roll bonding involves bonding the layers of the alloys by passing the layers through rolls under pressure either in presence or absence of heat. Lamination involves bonding the layers of the alloys by an adhesive in presence of heat.
The method is simple and easy to be carried out. The method comprising lamination technique or joining the alloy layers by adhesive does not reduce the thickness of the laminate.
The core layer has recyclable aluminium alloy selected from AA3xxx, AA4xxx, or AA8xxx series such as AA3105, AA4015, or AA8011 and the aluminium foil comprises of alloy composition selected from AA1xxx or AA8xxx series such as AA1050, AA1235 or AA8011.
In a preferred embodiment, an aluminium laminate comprises AA4015 as a core layer and AA1235 as an aluminium foil. The core layer is manufactured by direct chill (DC) casting, homogenization, hot and cold rolling. The foil is made by continuous casting, cold rolling and foil rolling to a thickness of 50 microns.

The foil is laminated with the core layer with its matte side in contact with the core layer (faying surface). The laminate has a reflectivity of greater than 80% in the UV-C wavelength range.
In another preferred embodiment the aluminium laminate comprises AA8011 manufactured by continuous casting laminated with AA1235 foil. The laminate has a reflectivity of greater than 80% in the UV-C wavelength range.
The foregoing description of the invention has been set merely to illustrate the invention and is not intended to be limiting. Since modifications of the disclosed embodiments incorporating the spirit and substance of the invention may occur to person skilled in the art, the invention should be construed to include everything within the scope of the disclosure.

We Claim:
1) A light reflective laminate comprising, at least one core layer having a first surface and second surface, said second surface of core layer is adhesively bonded with at least one reflective layer.
2) The laminate as claimed in claim 1, wherein said core layer and reflective layer is bonded by a layer of adhesive.
3) The laminate as claimed in claim 1, wherein, said core layer is made of recyclable aluminium alloy selected from group consisting of AA3xxx, AA4xxx or AA8xxx.
4) The laminate as claimed in claim 1, wherein said reflective layer is made of aluminium alloy selected from group consisting of AA1xxx or AA8xxx.
5) The laminate as claimed in claim 1, wherein thickness of said core layer is in the range of 0.2 to 3.0 mm.
6) The laminate as claimed in claim 1, wherein said core layer has a surface roughness of less than 0.2 micron.
7) The laminate as claimed in claim 1, wherein thickness of said reflective layer is in range of 6 microns to 50 microns.
8) The laminate as claimed in claim 1, having a reflectivity of at least 80% in the UV-C
wavelength.