Field of the invention

This invention relates to complex polymer modified bitumen emulsion adhesive membrane which can be applied cold directly on the surface. Buildt-Up roofing (BUR) which consists of multiple plies of membranes soaked with asphalt or coal tar pitch, has existed in its present form for close to a century. It continues to be the standard against which all other roofing systems are compared, according to the Asphalt Roofing Manufacturers Association.

Background and prior-art

Modified bitumens (known as 'mod bits') are asphaltic roofing materials modified with an elastomeric compound that is compatible with roofing asphalt. This blending improves the asphalt's low temperature flexibility and extensibility characteristics. Although officially classified as single- ply membranes, the increasing incorporation of mod bits into BUR systems makes them an integral part of the BUR market. When elastomers are added to the bitumen, the bitumen can be used either as a mopping asphalt or to saturate glass or fiber scrims. These applications represent the most common uses of mod bits.

Modified bitumen systems originated in Europe during the 1950s, with the first atactic polypropylene modified (APP) system applied in Italy. In the 1960s, the first styrene- butadiene-styrene (SBS) modified) system was installed in France. The first modified bitumen systems were seen in the United Stats in the mid 1970s.

United States Patent 6759454 teaches a polymer modified bituminous composition having improved phase stability, heat aging and viscosity characteristics. The bituminous compositions are blends comprising bitumen and from about 0.5 to about 25% of a novel anionic block, copolymer where one of the blocks is a controlled distribution copolymer of a conjugated diene and a mono-alkenyl arene having a specific arrangement of the monomers in the copolymer block. The composition of the invention is useful for paving, roofing felts, water-proof membrane, adhesive, mopping asphalt, carpet backing and pipe coating applications United States Patent 4011184 teaches a bitumen-polymer composition with improved elastomeric properties is prepared by chemically coupling a modified bitumen and a modified polymer with a metal compound wherein the bitumen and polymer are first modified.

United States Patent 5414029 teaches a bitumen-polymer emulsion containing:
a) at least one bitumen,

b) at least one polymer having hydrocarbon chains with mobile hydrogens, said polymer being grafted and crosslinked in situ in said bitumen through a complex of at least one organic silicon compound, said complex being formed from a primary constituent and a secondary constituent, the latter being an organic silicon compound,

c) water, and

d) at least one emulsifier.
United States Patent 6451885 teaches an aqueous bitumen emulsion, consisting of the following constituents expressed in weight percentages of the emulsion total weight: 50% to 70% of bitumen; 0.5% to 10% of surfactant; 0% to 5% of thickening agent; 0% to 1% of antifoaming agent; a sufficient quantity of water to make up 100%. Said emulsion is characterised in that the surfactant consists of at least a surfactant selected among the group consisting of an ethylene oxide and a propylene oxide copolymer, with PO/EO ratio ranging between 1.5 and 10, an ethoxylated and/or propoxylated epoxidized surfactant, and a polyvinyl alcohol having molecular mass ranging between 10000 and 150000. The invention also concerns the method for obtaining said emulsion, the compositions containing them, and the use of said bitumen emulsion adhesive membrane for the formulation of compositions comprising a hydraulic or organic binder, and/or a mineral or organic filler.

European Patent Application EP0604258 teaches a bitumen- polymer emulsion comprising: a) at least one bitumen, b) at least one polymer having hydrocarbon chains containing mobile hydrogen, the said polymer being grafted and crosslinked in situ in the said bitumen complex of at least one organic silicon compound, the said complex formed from a primary constituent and from a secondary constituent, the latter being the organic silicon compound, c) water, and d) at least one emulsifying agent.

In our earlier patent we have discussed the disadvantages of using bitumen / asphalt and it is now well known that these are not suitable products from the point of durable materials or toxicity and they are not environmentally friendly. This was followed by polymer modified bituminous roofing membranes. Polymer-modified bituminous roofing membranes were first introduced to the European market, with several countries offering various types of sheets with several different polymer modifiers. Atactic polypropylene (APP), styrene butadiene styrene (SBS) and styrene butadiene rubber (SBR) were the initial primary modifiers for asphalt, with reinforcing material varying between products. Glass fibers, polyester fibers and polyethylene film were used individually or in combination to stabilize and form a "carrier" for the polymer-modified asphalt membrane. Surfacing materials varied from glass-fiber mats inherent in the membrane to mineral granules to metallic foils by individual product.

Summary of the invention

A cold applied water-based polymer modified bitumen emulsion adhesive membrane comprises 30% to 70% of a water based emulsion i.e. component A , 40% to 60% of a thick liquid material marked as component B, 2% to 10% of biocide, wherein the ingredients are mixed in a clean and dry stainless steel reactor fitted with anchor stirrer to' obtain a thick paste material hereinafter called cold applied water-based polymer modified bitumen emulsion.

Detailed description of the invention

Modified bitumen membranes have been widely used throughout Canada for well over thirty years. A market survey conducted by CRCA in collaboration with NRCA revealed that SBS modified bitumen membrane (MBM) applications accounted for one half of the low-slope roofing sales of the survey respondents in 2000 and 2001 (Canadian Roofing Contractors' Association 2000-2001 Annual Market Survey). There are several recognized methods used to apply MBMs, including hot bitumen mopping, torching, the use of cold adhesives and more recently, the use of self- adhering (peel and stick) materials.

It is also claimed that the interplay bond strength of torched membranes, when properly applied, is superior to that of any other application due to the homogeneity of the layer of the polymer modified bitumen between adjoining sheets (Kersey, Tim et al. Performance Properties of Interply Adhesive Used with SBS-Modified Bitumen Membranes. 12th International Roofing and Waterproofing Conference. Orlando, 2002).

The pervasive use of torch on membranes has not been without associated costs. These are primarily related to the relatively high number of incidences of roof fires, allegedly caused by torching operations. In one of the countries the largest single construction occurred in 1999, when an entire condominium complex of wood frame construction was reduced to ashes when purportedly ignited by a roofers' torch.
In addition torching would create heat and temperature and would initiate oxidation of polyaromatic compound which would result in the emission of toxic gases some of which are carcinogenic.

The risks associated with torch welding have led to renewed interest in cold adhesive applied and self-adhering (peel and stick) MBM applications.

Cold Applied Water-based Polymer Modified Bitumen Emulsion
The applicant has been working on the concept of cold applied water-based polymer modified bitumen emulsion adhesive membrane products. This is a new concept which avoids all torching and heating. A thin membrane of 1-2 mm offers all the requirements, of breathable elastomeric membranes. Polymer Modified Bitumen often cannot meet the performance requirements and therefore approaches have been developed whereby polymers are added which are compatible with bitumen and change the properties of bitumen, such as making it breathable and elastic. Here it should be noted that the quality of the copolymers and their compatibility with bitumen is the most important and critical step.

The applicant has used compatible copolymers and blocks with other additives and catalysts, which increase the low temperature flexibility and high temperature softening point, increasing the temperature range for practical use. In addition improvements in fatigue resistance, thermal cracking and rutting resistance can all be achieved, as well as stress crack resistance of bitumen for cold temperature coating applications. The combination of certain cross linking agents in conjunction with selected block copolymers exhibits excellent high and low temperature characteristics and changes the inherent character of bitumen from viscous to visco-elastic.

The applicant have developed a possible structure and this is the type of copolymer block that is added and gains the properties of membrane making it breathable and elastic. For example, the applicant has tried different polymers, e.g. styrene-butadiene block copolymers. Our objective was not only to increase flexibility, penetration and waterproofing, but to create a cross-linked multifunctional compound which provides chemical strength along with flexibility and the capability of withstanding the UV light, heat, not cracking and not shrinking. These water-based, cold bitumen membranes developed by the applicant differ in their capacity of mechanical strength and other factors. They are a different block of co-polymers and the biggest advantage is that they are cross-linked and compatible with bitumen of different origin. We have tried it on bitumen from UK and Germany. Polymer Modified Membranes may undergo significant changes to their properties when exposed to light and temperature. The applicant products have no such problems and give breathable membranes with all the properties of flexibility, waterproofing and no disadvantages. These coatings are environmentally friendly products which are in line with our philosophy.

The applicant has been working on the concept of cold polymer modified bitumen and has developed some excellent membranes which can be applied in cold, coated by brush or sprayed to the thickness of about 1 to 2 mm. The beauty of this product is that it all depends on the selection of an appropriate polymer or polymixtures,
The applicant undertook first preparation of water based bitumen emulsion adhesive membrane modified by Styrene butadiene latex, acrylic ester and styrene, acrylic styrene co-polymer, acrylic acid ester co-polymer containing
acrylonitrile, acrylic acid ester co-polymer, butyl acrylate styrene etc. etc.

Protekta Elastofelt, Protekta Plastofelt and Protekta Plastoflex are the applicant's proprietary items for which the applicant have already filed under patent application Membranes for surface coating.

COLD APPLIED WATER-BASED POLYMER MODIFIED BITUMEN EMULSION ADHESIVE MEMBRANE HEREINAFTER CALLED AS PROTEKTA KOOL COAT PROCESS:

COMPONENT - A
Taking a clean and dry 200 Itrs stainless steel open vessel fitted with a homogenizer with 2800 rmp. Taking 45 to 65 % of water based bitumen emulsion adhesive membrane was taken into the above vessel and add 20 to 40% of DM water and stir for 5 minutes with 4000 rpm. Add 4 to 14% of non-ionic surfactant and 2 to 10% of colosing agent was added and stirred with material which are known as dispersion agent like polyacrylate and 2 to 8% of Alcohol ethoxylate. After 2 hours of stirring an water based emulsion was produced. This product is hereinafter called as component - A.

COMPONENT - B
Taking a clean and dry 200 Itr stainless steel reactor fitted with a homogeniser with 2800 rmp Taking 40 to 80% of acrylic or styrene or acrylic emulsion. Add 20 to 40% of DM Water stir for 5 minutes, add 2 to 6 % of thickener 0.5 to 2.5% of Anti foaming agent and 2 to 4% Biocide and stir for 15 minutes. After that you will get a thick liquid material hereinafter called as Component: - B

EXAMPLE - 1
Taking a clean and dry 100 Itrs stainless steel reactor fitted with anchor stirrer. Taking 45 to 65% of component A and 40 to 60% of component B and stir for 15 minutes, Add 2 to 6% of Biocide stir for 5 minutes. After 5 minutes you will get a thick paste material Protekta Koolcoat.

EXAMPLE - 2
Taking a clean and dry 100 Itrs stainless steel reactor fitted with anchor stirrer. Taking 30 to 70% of component A and 46 to 66% of component B and stir for 25 minutes. Add 5 to 10 of Biocide stir for 5 minutes. After 5 minutes you will get a thick paste material Protekta Koolcoat.

DISCRIPTIONS:
This is a polymer modified bitumen polymers used Protekta Elastofelt specially developed product of The applicant along with styrene acrylic non-ionic, styrene acrylic polymer and thermoplastic acrylic resin and other organic additives.
Uses Roofs (new & existing). Decks, Podiums, Box gutters, parapet walls, bay windows, vertical walls and facades, external floor, plant floors, silos and general weather exposed surfaces

PROPERTIES

Water based

Elastomeric & Flexible

• Waterproof & UV resistant

• Resistant to Fungi & Algae growth Resistant to salt and carbon attack Tough & Durable

• Available a range of colours

• Compatible over other coatings

Statement of the invention

According to the invention, a process for preparing cold applied water-based polymer modified bitumen emulsion adhesive membrane comprises the following steps: Step A-:

a) Taking a clean and dry 200 Itrs stainless steel open vessel fitted with a homogenizer with 2800 rpm,

b) Taking 45% to 65% of water based bitumen emulsion adhesive membrane into the vessel,

c) Adding 20% to 40% of DM water and stirring it for at least 5 minutes at 4000 rpm to get a homogeneous solution,

d) Adding 4% to 14% of non-ionic surfactant and 2% to 10% of colosing agent into the solution,

e) Stirring the solution with a dispersing agent and adding 2% to 8% of Alcohol ethoxylate,

f) Stirring the solution vigorously for 2 hours to obtain a water based emulsion hereinafter called as component A.

Step B-:

a) Taking a clean and dry 200 Itr stainless steel reactor fitted with a homogenizer with 2800 rpm.

b) Taking 40% to 80% of acrylic or styrene or acrylic emulsion into reactor,

c) Adding 20% to 40% of DM water and stirring for 5 minutes to get a homogeneous solution,

d) Adding 2% to 6% of thickener, 0.5% to 2.5% of anti foaming agent and 2% to 4% biocide into the solution,

e) Stirring the solution vigorously for 15 minutes to obtain a thick liquid material hereinafter called as Component B.

Step C-:

a) Taking a clean and dry 100 Itrs stainless steel reactor fitted with a anchor stirrer,

b) Taking 30% to 70% of component A and 40% to 66% of component B and stirring it for 25 minutes,

c) Adding 2% to 10% of biocide into the mixture,

d) Stirring the mixture for 5 minutes to obtain a thick paste material i.e. cold applied water-based polymer modified bitumen emulsion.

According to another embodiment of the invention, the dispersing agent is polyacrylate.

According to another embodiment of the invention, the colosing agent is polyacrylate.
According to the invention, a cold applied water-based polymer modified bitumen emulsion adhesive membrane comprises 30% to 70% of a water based emulsion i.e. component A, 40% to 60% of a thick liquid material marked as component B, 2% to 10% of biocide, wherein the ingredients are mixed in a clean and dry stainless steel reactor fitted with anchor stirrer to obtain a thick paste material hereinafter called cold applied water-based polymer modified bitumen emulsion.

According to another embodiment of the invention , a water based emulsion i.e. component A comprises 45% to 65% of water based bitumen emulsion, 20% to 40% of DM water, 4% to 14% of non-ionic surfactant, 2% to 10% of colosing agent, 2% to 8% of a dispersing agent and alcohol ethoxylate, wherein ingredients are mixed in a homogenizer at 2800 rpm to obtain a water based emulsion i.e. component A.

According to another embodiment of the invention , a thick liquid material i.e. component B comprises 40% to 80% of acrylic or styrene or acrylic emulsion, 20% to 40% of DM water, 2% to 6% of thickener, 0.5% to 2.5% of anti-foaming agent, 2% to 4% of biocide ,to obtain a thick liquid material i.e. component B.

Protekta Kool Coat is a Cold Applied Liquid Membrane prepared by water based bitumen emulsion adhesive membrane modified by polymers like Styrene butadiene latex, acrylic ester and styrene, acrylic styrene co-polymer, acrylic acid ester copolymer containing acrylonitrile, acrylic acid ester copolymer, butyl acrylate styrene, where the properties of bitumen are changed and this product is reacted with a above polymers in the presence of cross linker and a crosslink membrane is generated to waterproof a variety of external and exposed surfaces. Enhanced UV resistant properties enable this product to be used as a weatherproof membrane, while remaining flexible and durable offering long-term protection to substrates against climate conditions. Suitable for use over horizontal and vertical surfaces, Protekta Kool Coat will resist fungi and algae growth and prevents salt and carbon attack to substrates applied over.

We claim:-

1. A process for preparing cold applied water-based
polymer modified bitumen emulsion adhesive membrane |
comprising the following steps:

Step A-:
f) Taking a clean and dry 200 Itrs stainless steel open vessel fitted with a homogenizer with 2800 rpm,

g) Taking 45% to 65% of water based bitumen emulsion adhesive membrane into the vessel,

h) Adding 20% to 40% of DM water and stirring it for at least 5 minutes at 4000 rpm to get a homogeneous solution,

i) Adding 4% to 14% of non-ionic surfactant and 2% to 10% of colosing agent into the solution,

j) Stirring the solution with a dispersing agent and adding 2% to 8% of Alcohol ethoxylate,

e) Stirring the solution vigorously for 2 hours to obtain a water based emulsion hereinafter called as component A
Step B:
f) Taking a clean and dry 200 Itr stainless steel reactor fitted with a homogenizer with 2800 rpm,
g) Taking 40% to 80% of acrylic or styrene or acrylic emulsion into reactor,

h) Adding 20% to 40% of DM water and stirring for 5 minutes to get a homogeneous solution,
i) Adding 2% to 6% of thickener, 0.5% to 2.5% of anti foaming agent and 2% to 4% biocide into the solution.

j) stirring the solution vigorously for 15 minutes to obtain a thick liquid material hereinafter called as Component B.

Step C-:
a) Taking a clean and dry 100 Itrs stainless steel reactor fitted with a anchor stirrer,

d) Taking 30% to 70% of component A and 40% to 66% of component B and stirring it for 25 minutes,

e) Adding 2% to 10% of biocide into the mixture,

d) Stirring the mixture for 5 minutes to obtain a thick paste material i.e. cold applied water-based polymer modified bitumen emulsion.

2. A process as claimed in claim 1, wherein the dispersing agent is polyacrylate.

3. A process as claimed in claim 1, wherein the colosing agent is polyacrylate.

4. A cold applied water-based polymer modified bitumen emulsion adhesive membrane as claimed in claim 1 comprising 30% to 70% of a water based emulsion i.e. component A , 40% to 60% of a thick liquid material marked as component B, 2% to 10% of biocide, wherein the ingredients are mixed in a clean and dry stainless steel reactor fitted with anchor stirrer to obtain a thick paste material hereinafter called cold applied water-based polymer modified bitumen emulsion.

5. A cold applied water-based polymer modified bitumen emulsion adhesive membrane as claimed in claim 4, wherein component A comprises 45% to 65% of water based bitumen emulsion, 20% to 40% of DM water, 4% to 14% of non-ionic surfactant, 2% to 10% of colosing agent, 2% to 8% of a dispersing agent and alcohol ethoxylate, wherein ingredients are mixed in a homogenizer at 2800 rpm to obtain a water based emulsion i.e. component A.

6. A cold applied water-based polymer modified bitumen emulsion adhesive membrane as claimed in claim 4,wherein component B comprises 40% to 80% of acrylic or styrene or acrylic emulsion, 20% to 40% of DM water, 2% to 6% of thickener, 0.5% to 2.5% of anti- foaming agent, 2% to 4% of biocide to obtain a thick liquid material i.e. component B.

7. A process for preparing cold applied water-based polymer modified bitumen emulsion adhesive membrane substantially as hereinbefore described with reference to the accompanying examples.

8. A cold applied water-based polymer modified bitumen emulsion adhesive membrane substantially as hereinbefore described with reference to the accompanying examples.