Thermoplastic films for heat seaming roof sheeting and method for covering roofs

• US 5,486,249 A
• Filed: 12/05/1994
• Issued: 01/23/1996
• Est. Priority Date: 08/08/1991
• Status: Expired due to Term

• Current Assignee: Firestone Building Products Company LLC (Bridgestone Corporation)
• Original Assignee: Bridgestone Corporation
• Inventors: Davis, James A., Lohr, Frederick, Valaitis, Joseph K.
• Primary Examiner(s): Ball, Michael W.
• Assistant Examiner(s): Stemmer, Daniel J.
• Application Number:
  US08/349,139
• Time in Patent Office: 414 Days
• Field of Search: 156/71, 156/157, 156/306.6, 156/308.4, 156/309.6, 428/57, 428/58, 428/141, 428/147, 428/255, 428/295, 428/517, 428/519, 428/521, 428/520, 525/97
• US Class Current: 156/71
• CPC Class Codes: B29C 65/14 using wave energy , i.e. electromagnetic radiation, or particle radiation using mechanical waves B29C65/06; using ultrasonic waves B29C65/08; pressing means transparent to electromagnetic radiation B29C66/81267
• CPC Class Codes: B29C 65/4815 Hot melt adhesives, e.g. thermoplastic adhesives
• CPC Class Codes: B29C 65/5014 being fibre-reinforced B29C65/5028 takes precedence
• CPC Class Codes: B29C 65/5057 positioned between the surfaces to be joined B29C65/5035 takes precedence
• CPC Class Codes: B29C 66/1122 Single lap to lap joints, i.e. overlap joints B29C66/45, B29C66/472, B29C66/52272 take precedence
• CPC Class Codes: B29C 66/43 Joining a relatively small portion of the surface of said articles B29C66/45 takes precedence
• CPC Class Codes: B29C 66/71 characterised by the composition of the plastics material of the parts to be joined welding bar compositions B29C65/125
• CPC Class Codes: B29C 66/721 Fibre-reinforced materials B29C66/729 takes precedence
• CPC Class Codes: B29C 66/7375 uncured, partially cured or fully cured
• CPC Class Codes: B29C 66/73751 the to-be-joined area of at least one of the parts to be joined being uncured, i.e. non cross-linked, non vulcanized
• CPC Class Codes: B29C 66/73752 the to-be-joined areas of both parts to be joined being uncured
• CPC Class Codes: B29C 66/73755 the to-be-joined area of at least one of the parts to be joined being fully cured, i.e. fully cross-linked, fully vulcanized
• CPC Class Codes: B29C 66/73756 the to-be-joined areas of both parts to be joined being fully cured
• CPC Class Codes: B29C 66/73774 the to-be-joined areas of both parts to be joined being semi-crystalline
• CPC Class Codes: B29C 66/73776 the to-be-joined areas of both parts to be joined being crystalline
• CPC Class Codes: B29C 66/73941 characterised by the materials of both parts being thermosets
• CPC Class Codes: B29C 66/9141 by controlling or regulating the temperature
• CPC Class Codes: B29C 66/91411 of the parts to be joined, e.g. the joining process taking the temperature of the parts to be joined into account
• CPC Class Codes: B29C 66/919 characterised by specific temperature, heat or thermal flux values or ranges specific electrical resistance values B29C66/81262
• CPC Class Codes: B29C 66/91933 higher than said fusion temperature
• CPC Class Codes: B29C 66/929 : characterized by specific pressure, force, mechanical power or displacement values or ranges
• CPC Class Codes: B29C 66/949 : characterised by specific time values or ranges
• CPC Class Codes: B29K 2011/00 : Use of rubber derived from chloroprene as moulding material
• CPC Class Codes: B29K 2021/00 : Use of unspecified rubbers as moulding material
• CPC Class Codes: B29K 2023/00 : Use of polyalkenes or derivatives thereof as moulding material
• CPC Class Codes: B29K 2023/06 : PE, i.e. polyethylene
• CPC Class Codes: B29K 2023/065 : HDPE, i.e. high density polyethylene
• CPC Class Codes: B29K 2023/0683 : UHMWPE, i.e. ultra high molecular weight polyethylene
• CPC Class Codes: B29K 2023/08 : Copolymers of ethylene B29K2023/16 takes precedence
• CPC Class Codes: B29K 2023/083 : EVA, i.e. ethylene vinyl acetate copolymer
• CPC Class Codes: B29K 2023/12 : PP, i.e. polypropylene
• CPC Class Codes: B29K 2023/14 : Copolymers of polypropylene B29K2023/16 takes precedence
• CPC Class Codes: B29K 2023/16 : EPM, i.e. ethylene-propylene copolymers; EPDM, i.e. ethylene-propylene-diene copolymers; EPT, i.e. ethylene-propylene terpolymers
• CPC Class Codes: B29K 2023/18 : Polymers of hydrocarbons having four or more carbon atoms, e.g. polymers of butylene, e.g. PB, i.e. polybutylene
• CPC Class Codes: B29K 2027/06 : PVC, i.e. polyvinylchloride
• CPC Class Codes: B29K 2101/12 : Thermoplastic materials
• CPC Class Codes: B29K 2105/06 : containing reinforcements, fillers or inserts
• CPC Class Codes: B29K 2105/16 : Fillers
• CPC Class Codes: B29K 2105/243 : Partially cured
• CPC Class Codes: B29K 2105/246 : Uncured, e.g. green
• CPC Class Codes: B29K 2995/004 : Semi-crystalline
• CPC Class Codes: B29L 2031/108 : Roofs
• CPC Class Codes: B32B 3/06 : for securing layers together; for attaching the product to another member, e.g. to a support , or to another product, e.g. groove/tongue, interlocking
• CPC Class Codes: E04D 5/142 : along the edge of the flexible material
• CPC Class Codes: E04D 5/148 : fastening by gluing
• CPC Class Codes: Y10T 428/19 : Sheets or webs edge spliced or joined
• CPC Class Codes: Y10T 428/192 : Sheets or webs coplanar
• CPC Class Codes: Y10T 428/24355 : Continuous and nonuniform or irregular surface on layer or component [e.g., roofing, etc.]
• CPC Class Codes: Y10T 428/24405 : Polymer or resin [e.g., natural or synthetic rubber, etc.]
• CPC Class Codes: Y10T 428/31917 : Next to polyene polymer
• CPC Class Codes: Y10T 428/31924 : Including polyene monomers
• CPC Class Codes: Y10T 428/31928 : Ester, halide or nitrile of addition polymer
• CPC Class Codes: Y10T 428/31931 : Polyene monomer-containing

Abstract

A laminate seam of flat rubber sheet material for roofing comprising two layers (10, 11) of the sheet material, at least one layer of which is uncured or cured, and one layer of a thermoplastic film (14) interposed between the overlapped edges (12,13) of the two layers of sheeting material to form a seam without the use of an adhesive. A method for covering a roof comprises the steps of applying a thermoplastic film (14) to the edge (12) of at least one layer of a flat rubber sheet material (10); applying a second layer of flat rubber sheet material (11 ) overlapping the thermoplastic film and the edge of the first flat rubber sheet material; heating the overlapped area to a temperature slightly above the peak melt temperature of the thermoplastic film; and, seaming the overlapped area under sufficient heat and pressure to provide an acceptable seam without the use of an adhesive.

Claims

1. A method for covering roofs comprising the steps of:

applying a thermoplastic film to the edge area of at least one layer of a flat rubber sheet material, said sheet material consisting essentially of a polymeric composition of matter consisting essentially of a semi-crystalline polyolefin rubber having more than about 2 percent by weight crystallinity and an ethylene content in excess of 60 percent, selected from the group consisting of ethylene-propylene copolymers and terpolymers;

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; and

from about 20 to 150 parts by weight of a processing material and mixtures thereof, per 100 parts of said polymer;

applying a second layer of said flat rubber sheet material overlapping said thermoplastic film and the edge area of said first layer of flat rubber sheet material, at least one of said first and second layers of flat rubber sheet material being uncured;

heating the overlapped areas to slightly above the peak melt temperature of the thermoplastic film, said uncured layer of flat rubber sheet material remaining uncured after heating; and

seaming the overlapped area under sufficient heat and pressure for less than about 5 minutes to provide a seam, said sheet material exhibiting a seam peel adhesion value of at least 2 pounds/inch and a shear adhesion value of at least about 15 pounds/square inch, in the absence of a pressure sensitive adhesive.

2. A method, as set forth in claim 1, wherein said step of heating is conducted under a temperature of at least about 100°

C.

3. A method, as set forth in claim 1, wherein said thermoplastic film is selected from the group consisting of polyolefins prepared from monomers having from 2 to about 8 carbon atoms, ethylene-vinyl acetate copolymers and blends thereof.

4. A method, as set forth in claim 1, wherein said filler comprises about 110 parts by weight of carbon black and said composition of matter includes about 70 parts by weight of processing oil.

5. A method, as set forth in claim 1, wherein said flat rubber sheet material is scrim-reinforced.

6. A method, as set forth in claim 1, wherein said flat rubber sheet material is unreinforced.

7. A method, as set forth in claim 1, including the step of selecting a thermoplastic film having a thickness of at least 2 mils.

8. A method for covering roofs comprising the steps of:

applying a thermoplastic film to the edge area of at least one layer of a flat rubber sheet material, said sheet material consisting essentially of a polymeric composition of matter consisting essentially of a semi-crystalline polyolefin rubber having more than about 2 percent by weight crystallinity and an ethylene content in excess of 60 percent, selected from the group consisting of ethylene-propylene copolymers and terpolymers;

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 100parts of said polymer; and

from about 20 to 150 parts by weight of a processing material and mixtures thereof, per 100 parts of said polymer;

applying a second layer of said flat rubber sheet material overlapping said thermoplastic film and the edge area of said first layer of flat rubber sheet material, at least one of said first and second layers of flat rubber sheet material being uncured;

heating the overlapped areas to slightly above the peak melt temperature of the thermoplastic film, said uncured layer of flat rubber sheet material remaining uncured after heating; and

seaming the overlapped area under sufficient heat and pressure for less than about 5 minutes to provide a seam, said sheet material exhibiting a seam peel adhesion value of at least 2 pounds/inch and a shear adhesion value of at least about 15 pounds/square inch, in the absence of any solvent-activated adhesive.

9. A method for covering roofs comprising the steps of:

applying a thermoplastic film to the edge area of at least one layer of a flat rubber sheet material, said sheet material consisting essentially of a polymeric composition of matter consisting essentially of a semi-crystalline polyolefin rubber having more than about 2 percent by weight crystallinity and an ethylene content in excess of 60 percent, selected from the group consisting of ethylene-propylene copolymers and terpolymers;

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; and

from about 20 to 150 parts by weight of a processing material and mixtures thereof, per 100 parts of said polymer;

applying a second layer of said flat rubber sheet material overlapping said thermoplastic film and the edge area of said first layer of flat rubber sheet material, at least one of said first and second layers of flat rubber sheet material being uncured;

heating the overlapped areas to slightly above the peak melt temperature of the thermoplastic film, said uncured layer of flat rubber sheet material remaining uncured after heating; and

seaming the overlapped area under sufficient heat and pressure for less than about 5 minutes to provide a seam, said sheet material exhibiting a seam peel adhesion value of at least 2 pounds/inch and a shear adhesion value of at least about 15 pounds/square inch, in the absence of any adhesive having tack prior to the application of heat.