Roofing membranes, compositions, and methods of making the same

#The present disclosure generally relates to compositions that may be used to form thermoplastic roofing membranes, and more particularly, to silane-grafted polyolefin elastomer compositions used to form thermoplastic roofing membranes and methods for manufacturing these compositions and roofing membranes.

#Thermoplastic roofing membranes may be a single layer or may be composed of multiple layers and may contain a reinforcing fabric or scrim reinforcement material in the center between any two of the layers of the roofing membrane. Each of the respective layers in the roofing membrane needs to demonstrate a variety of different material properties in order to be suited for use on a roof where the material will be exposed to the sun and the elements. The material properties of the polymer layers should exhibit good adhesion, UV resistance, weatherability (durability), flame retardance, flexibility, chemical resistance and longevity. In addition, roofing membranes should preferably be capable of forming hot-air welded seams.

#Many different polymer systems are available to be used for roofing membranes. The most commonly used polymer systems include thermoplastic polyolefin (TPO), ethylene propylene diene monomer (EPDM), and polyvinyl chloride (PVC). Depending on the material(s) selected, different advantages and disadvantages are typically observed. TPO membranes are widely available, affordable, and typically white, but are susceptible to deterioration when exposed to high heat and/or solar UV radiation. EPDM membranes are made from the readily available EPDM synthetic rubber, but roughly 95% of all EPDM roofing membranes produced are black while federal and state building regulators are starting to push for white roofing membranes. Lastly, PVC membranes are widely available and offer excellent puncture, heat-weldability, colorability, and heat resistant qualities, but these membranes can be expensive to manufacture and suffer from variability in properties as produced by different manufacturers.

#In the drawings:

#FIG. 1 is a cross-sectional view of a roofing membrane according to some aspects of the present disclosure;

#FIG. 2 is a schematic reaction pathway used to produce a silane-crosslinked polyolefin elastomer according to some aspects of the present disclosure;

#For purposes of description herein the terms “upper,” “lower,” “right,” “left,” “rear,” “front,” “vertical,” “horizontal,” and derivatives thereof shall relate to the roofing membranes of the disclosure as shown in FIG. 1. However, it is to be understood that the device may assume various alternative orientations and step sequences, except where expressly specified to the contrary. It is also to be understood that the specific devices and processes illustrated in the attached drawings, and described in the following specification are simply exemplary embodiments of the inventive concepts defined in the appended claims. Hence, specific dimensions and other physical characteristics relating to the embodiments disclosed herein are not to be considered as limiting, unless the claims expressly state otherwise.

#All ranges disclosed herein are inclusive of the recited endpoint and independently combinable (for example, the range of “from 2 to 10” is inclusive of the endpoints, 2 and 10, and all the intermediate values). The endpoints of the ranges and any values disclosed herein are not limited to the precise range or value; they are sufficiently imprecise to include values approximating these ranges and/orvalues.

#A value modified by a term or terms, such as “about” and “substantially,” may not be limited to the precise value specified. The approximating language may correspond to the precision of an instrument for measuring the value. The modifier “about” should also be considered as disclosing the range defined by the absolute values of the two endpoints. For example, the expression “from about 2 to about 4” also discloses the range “from 2 to 4.”