Method of covering roofs with rooftop curable heat seamable roof sheeting

• US 5,512,118 A
• Filed: 10/11/1994
• Issued: 04/30/1996
• Est. Priority Date: 04/24/1991
• Status: Expired due to Term

• Current Assignee: Firestone Building Products Company LLC (Bridgestone Corporation)
• Original Assignee: Bridgestone Firestone North American Tire LLC (Bridgestone Corporation)
• Inventors: Davis, James A., Valaitis, Joseph K.
• Primary Examiner(s): Johnstone, Adrienne C.
• Application Number:
  US08/320,871
• Time in Patent Office: 567 Days
• Field of Search: 156/71, 156/157, 156/307.1, 156/308.4, 52/746, 52/408, 52/746.11, 428/57, 428/141, 428/147, 428/149, 524/492-495, 524/576, 524/580-581
• US Class Current: 156/157
• CPC Class Codes: C08K 3/011 Crosslinking or vulcanising agents, e.g. accelerators
• CPC Class Codes: C08K 3/04 Carbon
• CPC Class Codes: C08K 3/06 Sulfur
• CPC Class Codes: C08L 23/06 Polyethene
• CPC Class Codes: C08L 23/16 Elastomeric ethene-propene or ethene-propene-diene copolymers, e.g. EPR and EPDM rubbers
• CPC Class Codes: C08L 23/20 having four to nine carbon atoms
• CPC Class Codes: C08L 2312/00 Crosslinking
• CPC Class Codes: C08L 2666/02 Organic macromolecular compounds, natural resins, waxes or and bituminous materials
• CPC Class Codes: E04D 5/06 by making use of plastics
• CPC Class Codes: Y10T 428/19 Sheets or webs edge spliced or joined
• CPC Class Codes: Y10T 428/24421 Silicon containing

Abstract

A rooftop curable heat seamable sheet material for roofing prepared from an uncured polymeric composition of matter comprises 100 parts by weight of a semi-crystalline polymer having more than about 2 percent by weight crystallinity and selected from the group consisting of polyolefins prepared from monomers containing at least 2 carbon atoms from about 20 to 300 parts by weight of a filler selected from the group consisting of reinforcing and non-reinforcing materials and mixtures thereof per 100 parts of polymer; from about 20 to 150 parts by weight of a processing material and mixtures thereof, per 100 parts of polymer; and from about 1.5 to 10 parts by weight of a cure package capable of allowing the composition of matter to cure at temperatures of at least about 50° C. A method for covering a roof is also provided and comprises the steps of applying layers of rooftop curable sheet material prepared from an uncured heat seamable polymeric composition of matter to the roof being covered; overlapping adjacent edges of the layers; and seaming the overlapping areas under sufficient heat and some pressure to provide acceptable seam strength, the composition of matter being curable at temperatures of at least about 50° C., a temperature readily encountered on the roof of a building.

Claims

1. A method for covering a roof comprising the steps of:

applying layers of rooftop curable sheet material prepared from an uncured heat seamable polymeric composition of matter to the roof being covered, wherein said composition of matter of each layer consists essentially of

100 parts by weight of a curable semi-crystalline polymer having more than about 2 percent by weight crystallinity and selected from the group consisting of polyolefins prepared from monomers containing at least 2 carbon atoms, said polymer having an ethylene content of at least 60 percent by weight and having up to about 3.7 weight percent unsaturation;

from about 20 to 300 parts by weight of a filler selected from the group consisting of reinforcing and non-reinforcing materials and mixtures thereof, per 100 parts of said polymer;

from about 20 to 150 parts by weight of at least one processing material, per 100 parts of said polymer; and

from about 1.5 to 10 parts by weight of a sulfur cure package having at least one vulcanizing accelerator, said cure package capable of allowing said composition of matter to cure at temperatures of from about 50°

C. to about 69°

C.;

overlapping adjacent edges of said layers; and

seaming the overlapped areas under sufficient heat and pressure to provide a peel adhesion seam strength at 70°

C., when preheated 15 minutes prior to testing, of greater than 2.9 pounds/inch and a seam shear strength at 70°

C., when preheated 15 minutes prior to testing, of greater than 27.5 pounds/square inch, said composition of matter being curable at temperatures of from about 50°

C. to about 69°

C.

2. A method, as set forth in claim 1, wherein said polymer comprises an ethylene-propylene-diene terpolymer having an ethylene content of 76 percent by weight, a weight average molecular weight of about 190,000 and about 14.6 percent by weight crystallinity.

3. A method, as set forth in claim 2, wherein said filler comprises about 120 parts by weight of carbon black and said composition of matter includes about 75 parts by weight of processing oil, per 100 parts of said polymer.

4. A method, as set forth in claim 2, wherein said cure package comprises from about 0.25 to 2 parts by weight of sulfur;

from about 1 to 4 parts by weight of at least one thiuram accelerator;

from about 0.25 to 2 parts by weight of a thiazole accelerator and, from about 1 to 2.5 parts by weight of a sulfenamide accelerator, per 100 parts by weight of said polymer.

5. A method, as set forth in claim 4, wherein said cure package comprises 1.25 parts by weight of sulfur;

1 part by weight of a thiuram accelerator;

0.5 to 1 parts by weight of a thiazole accelerator and, 1 to 2 parts by weight of a sulfenamide accelerator, per 100 parts by weight of said polymer.

6. A method, as set forth in claim 1, wherein said polymer comprises an ethylene-propylene-diene terpolymer having an ethylene content of 71 percent by weight, a weight average molecular weight of about 333,000 and about 9 percent by weight crystallinity.

7. A method, as set forth in claim 6, wherein said filler comprises about 130 parts by weight of carbon black and said at least one processing material comprises about 90 parts by weight of processing oil, per 100 parts of said polymer.

8. A method, as set forth in claim 6, wherein said cure package comprises from about 0.25 to 2 parts by weight of sulfur;

from about 1 to 4 parts by weight of at least one thiuram accelerator;

from about 0.25 to 2 parts by weight of a thiazole accelerator; and

from about 1 to 2.5 parts by weight of a sulfenamide accelerator, per 100 parts of said polymer.

9. A method, as set forth in claim 8, wherein said cure package comprises 1.25 parts by weight of sulfur, 1 part by weight of a thiuram accelerator;

0.5 to 1 parts by weight of a thiazole accelerator, and 1 to 2 parts by weight of a sulfenamide accelerator, per 100 parts of said polymer.

10. A method for covering a roof comprising the steps of:

applying layers of rooftop curable sheet material prepared from an uncured heat seamable polymeric composition of matter to the roof being covered, wherein said composition of matter of each layer consists essentially of

100 parts by weight of a curable semi-crystalline polymer having more than about 2 percent by weight crystallinity and selected from the group consisting of polyolefins prepared from monomers containing at least 2 carbon atoms, said polymer having an ethylene content of at least 60 percent by weight;

from about 20 to 300 parts by weight of a filler selected from the group consisting of reinforcing and non-reinforcing materials and mixtures thereof, per 100 parts of said polymer;

from about 20 to 150 parts by weight of at least one processing material, per 100 parts of said polymer; and

from about 1.5 to 10 parts by weight of a sulfur cure package having at least one vulcanizing accelerator, said cure package capable of allowing said composition of matter to cure at temperatures of from about 50°

C. to 69°

C.;

overlapping adjacent edges of said layers; and

seaming the overlapped areas under sufficient heat and pressure to provide acceptable seam strength, said composition of matter being curable at temperatures of from about 50°

C. to 69°

C.