Gilsonite SBS Modified AsphaltTechnical field
The present invention relates to a modified asphaltbased material suitable for preparing a membrance sheeting useful for roofing purposes. Particularly, this invention relates to asphalt roofing material which is elastomeric and flexible with improved stiffness and hardness,and which has improved high temperature stability and long term resistance to environmental conditions.
Background of the invention
Asphalt roof sheeting is typically used as a single ply roofing membrance are usually processed into sheeting rolls and applied to roof in long strips . ordinarily , these sheets are joined to each other and to the substrate by heating, usually with a torch, so as to create a continuous roofing surface.
Asphalt roof sheeting is typically used as a single ply roofing membrane for industrial and commercial flat roof these membrances are usually processed into sheeting rolls and applied to roofs in long strips. Installation of these membranes requires adjoining the strips together to form a continuous roofing surface. These membranes are typically adjoined by using some form of adhesive or,more desirably, by heating.
Elasticity and flexibility facilitate processing, installation and most importantly overall use of the asphalt membrane. It is well known in the art to add synthetic or natural polymeric material to the asphalt-based membrane, thereby achieving elasticity and flexibility. Typically, vinyl containing polymers are added to accomplish such results.
Although the addition of vinyl containing polymers results in the desired flexibility and elasticity, their addition has at the same time limited the methods which can be used to adjoin the seams. Ideally, the seams are torched or heated which slightly melts the membranes allowing them to flow together. The vinyl containing polymers, however, will crosslink in the presence of high heat , thus inhibiting the ability of the membranes to flow together. Further, crosslinking causes the viscosity of the membrane to increase , decreasing the melt flow of the membrane which adds further obstacle to adjoining the membranes. As a result , other methods of adhesion are employed to adjoin the seams of vinyl containing membranes , a typical example being the use of a bonding adhesive.
To download full information please click on download pdf button.