Roofing adhesive

Abstract

An adhesive for a roofing material includes an asphalt material and reinforcing fibers dispersed in the asphalt material. The reinforcing fibers have an average length within a range of from 1.6 mm to 10 mm. The adhesive is capable of adhesively bonding a first asphalt-based roofing material to a second asphalt-based roofing material or to a roof. The adhesive is processable by conventional adhesive manufacturing equipment. In one embodiment, the adhesive further comprises a polymer mixed with the asphalt material to produce a polymer modified asphalt.

Description

BACKGROUND OF THE INVENTION

This invention relates in general to adhesives, and in particular to a roofing adhesive for use in bonding asphalt-based roofing materials together.

Roofing adhesives are used in various applications. For example, they are used during the manufacture of laminated roofing shingles to bond together the different pieces of the shingles. They are also used during the application of roofing materials on roofs. For example, when roofing shingles are laid on a roof, typically an adhesive is used to bond the tab portions of an upper course of shingles to the headlap portions of the adjacent lower course of shingles. Roofing adhesives are also used for bonding sheets of roll roofing together on a roof.

Conventional roofing adhesives are usually made from oxidized asphalt and/or polymer modified asphalt. These adhesives rely on the stiffness of the asphalt for their bond strength.

Some different types of roofing adhesives are described in the following patents. U.S. Pat. No. 4,755,545 by Lalwani (GAF Corp.), issued Jul. 5, 1988, discloses a self-sealing roofing adhesive comprising a bituminous component, a thermoplastic block polymer, and 4-40 wt % inert filler. Suitable fillers include limestone, stone dust, or ground glass fibers to add strength. The bituminous component is a road paving asphalt or a blend of road paving asphalt and hard resin asphalt. The road paving asphalt has a softening point of 110-130° F., a viscosity of 1,000-5,000 poise, and a penetration of 40-80 dmm at 77° F. The hard resin asphalt has a softening point of 165-195° F., and a penetration of 30-60 dmm at 130° F. The adhesive has a peel strength between 1.5 lbs. and about 6 lbs. at 75° F.

U.S. Pat. No. 4,923,913 by Chich et al. (GAF Corp.), issued May 8, 1990, discloses a self-sealing roofing adhesive comprising a hard asphaltic bitumen fraction, an elastomeric composition composed of a thermoplastic elastomer and a plasticizer, and 5-50 wt % filler such as ground glass fibers, limestone or stone dust. The hard asphaltic fraction has a softening point of 150° F.-220° F. and a penetration of 0-30 dmm at 77° F. The adhesive has a softening point of 140° F.-230° F., and a penetration of 30-100 dmm at 130° F.

U.S. Pat. No. 6,753,362 by Khan et al. (Building Materials Inv. Corp.), issued Jun. 22, 2004, discloses a roofing adhesive comprising a non-blown asphalt optionally containing a minor amount of blown asphalt, a block copolymer, 13-30 wt % hydrocarbon solvent, and optionally 0-10 wt % reinforcing fibers. The reinforcing fibers are preferably cellulose fibers having a length of 0.02-1.5 mm and a diameter of not more than 0.06 mm. The adhesive preferably has a viscosity of 60-140 cps and a penetration of 50-120 dmm at 25° C. An example of the adhesive has a peel strength of 13.5 foot lbs./inch at ambient temperature.

U.S. Pat. No. 5,362,316 by Paradise (Imperbel America Corp.), issued Nov. 8, 1994, discloses a roofing adhesive comprising asphalt or polymer modified asphalt, terpene solvent, and optionally a filler such as an organic or inorganic fiber, limestone or stone dust. The examples include 1-6 wt % cellulose fibers and 20-40 wt % limestone. The asphalt can be an oxidized asphalt or an asphalt flux such as those used in roof coatings and waterproofing applications. The roofing adhesive has a viscosity of 30,000-50,000 cps at 77° F.

U.S. Pat. No. 5,929,144 by Fields (unassigned), issued Jul. 27, 1999, discloses a roofing asphalt comprising oxidized asphalt, SEBS polymer, solvent, and optionally fibers and/or fillers. The oxidized asphalt has a softening point greater than 225° F. The mixture of asphalt and polymer has a viscosity of 50-350 cps at 400° F., and a softening point between 90° F. and 225° F. depending on the polymer content.

SUMMARY OF THE INVENTION

This invention relates to an adhesive for a roofing material. The adhesive comprises an asphalt material and reinforcing fibers dispersed in the asphalt material. The reinforcing fibers have an average length within a range of from 1.6 mm to about 10 mm. The adhesive is capable of adhesively bonding a first asphalt-based roofing material to a second asphalt-based roofing material or to a roof. The adhesive is processable with conventional adhesive manufacturing equipment. In one embodiment, the. adhesive further comprises a polymer mixed with the asphalt material to produce a polymer modified asphalt in which the fibers are dispersed.

In another embodiment, the invention relates to an adhesive for a roofing material which comprises an asphalt material, reinforcing fibers dispersed in the asphalt material, and roofing filler dispersed in the asphalt material.

In another embodiment, the invention relates to a roofing assembly. The roofing assembly comprises a first asphalt-based roofing material, and an adhesive which is capable of adhesively bonding the first roofing material to a second asphalt-based roofing material or to a roof. The adhesive comprises an asphalt material and reinforcing fibers dispersed in the asphalt material. The reinforcing fibers have an average length within a range of from 1.6 mm to about 10 mm.

In a further embodiment, the invention relates to a method of manufacturing an adhesive for a roofing material. The method comprises mixing a reinforced asphalt material with a filled asphalt material to produce the adhesive. The reinforced asphalt material comprises a first asphalt material and reinforcing fibers dispersed in the first asphalt material. The filled asphalt material comprises a second asphalt material and roofing filler dispersed in the second asphalt material. The adhesive is capable of adhesively bonding a first asphalt-based roofing material to a second asphalt-based roofing material or to a roof. In one embodiment, the reinforced asphalt material further comprises a polymer.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present invention relates to a roofing adhesive having increased bond strength compared to conventional roofing adhesives made from oxidized asphalt and/or polymer modified asphalt. The roofing adhesive contains reinforcing fibers that provide optimum bond strength gains per unit of fiber. At the same time, the reinforcing fibers are selected to reduce any difficulties in processing the adhesive with conventional manufacturing equipment. For example, the type, size and amount of the fibers can be selected so that the resulting adhesive provides a strong bond but does not have a viscosity which is too high for processing with conventional equipment.

The adhesive is capable of adhesively bonding a first asphalt-based roofing material to a second asphalt-based roofing material or to a roof. The asphalt-based roofing materials can be pieces of roof covering products that are bonded together during manufacture of the roof covering product, for example, the different pieces of a laminated roofing shingle (such an adhesive being commonly referred to as a “laminate adhesive”). The asphalt-based roofing materials can also be first and second roof covering products that are bonded together on a roof, such as roofing shingles, sheets of roll roofing, or any other type of asphalt-based materials suitable for use as roof coverings (such an adhesive being commonly referred to as a “sealant”). The roof can be any part of the roof of a building or any material which is attached to the roof beneath the roof covering, for example, it can be a roof deck or a waterproof membrane attached to the deck.

In one embodiment, the adhesive is used in conjunction with, or as an adhesive for bonding, a reinforcement member used on a roofing shingle, and preferably where the reinforcement member defines a nail zone of the shingle, as described in U.S. patent application Ser. No. 11/198,522 (the '522 application), entitled “Shingle with Reinforced Nail Zone and Method of Manufacturing”, filed Aug. 5, 2005(incorporated by reference herein in its entirety). The reinforcement member may be attached as taught in the '522 application, or with the adhesive at different locations on the roofing shingle, and it may be used with different types of roofing shingles such as three-tab shingles (commonly as sealant) and laminated shingles (commonly as laminate adhesive and/or sealant).

The adhesive includes an asphalt material and the reinforcing fibers dispersed in the asphalt material. By “asphalt material”, as used herein, is meant any type of bituminous material suitable for use on a roof covering, such as asphalts, tars, pitches, asphaltites, or mixtures thereof. The asphalt can be either a naturally occurring asphalt or a manufactured asphalt, such as an asphalt produced by refining petroleum or by other known means. The asphalt can be an oxidized asphalt (produced by an air-blowing process) or an asphalt flux. Mixtures of different asphalts can also be used. In one embodiment, the asphalt is an oxidized asphalt having a softening point of at least about 150° F. (66° C.), preferably within a range of from about 200° F. to about 240° F., and more preferably from about 210° F. to about 230° F. Preferably, the asphalt has a penetration within a range of from about 15 to about 22 at 77° F. (25° C.).

In one embodiment, the adhesive also includes one or more polymers mixed with the asphalt material to produce a polymer modified asphalt. Any type of polymer suitable for producing an adhesive having the properties described herein can be used. Preferably, the polymer is an elastomer. For example, the elastomer may be a diene rubber or butadiene based polymer or co-polymer, preferably a styrenic elastomer, such as a styrene-butadiene random copolymer (SBR), a di-block copolymer (SB), a tri-block copolymer (SBS), or a combination thereof. The polymer modified asphalt preferably has a softening point within a range of from about 170° F. (77° C.) to about 220° F. (104° C.).

In one embodiment, the adhesive further includes one or more roofing fillers dispersed in the asphalt material. Any type of filler suitable for use in an asphalt roofing material can be used, e.g., mineral filler/stabilizers such as small particles of limestone, silica, dolomite or other rocks. The filler can be included in any suitable amount. In some embodiments, the filler is included in an amount within a range of from about 20 wt % to about 70 wt %, and preferably from about 30 wt % to about 50 wt %.

The reinforcing fibers dispersed in the asphalt material can be any that are suitable for providing the above-described bond strength and processing advantages. The fibers can be any suitable type, or a mixture of different types, and they can be naturally occurring fibers or fibers manufactured from a fiberizable material. Some examples of inorganic reinforcing fibers include fibers made from a fiberizable mineral material, such as glass, rock, slag, basalt or diabase; and metal fibers such as fibers made from or coated with aluminum, copper, silver, iron or chromium. Inorganic fibers such as glass fibers are preferred because they are substantially non-absorbent relative to the asphalt material, resulting in a lower processing viscosity that facilitates manufacturing the adhesive with conventional processing equipment.

Some examples of organic reinforcing fibers include carbon fibers, and fibers made from polymers, including polypropylene, polyester such as polyethylene terephthalate, poly-paraphenylene terephthalamide (KEVLAR®), polyisobutylene, polyamide (e.g., NYLON®), regenerated cellulose (e.g., RAYONS®), polyphenylene such as polyphenylene sulfide, polyolefin, polyurethane, polycarbonate, polystyrene, acrylic, and vinyl polymer. The polymer fibers may be reclaimed or scrap fibers. Naturally occurring organic fibers include cellulosic fibers such as wood pulp, flax or jute.

The reinforcing fibers can have any suitable size. In some embodiments, relatively short fiber lengths are used to reduce any difficulties in processing the adhesive. Preferably, the reinforcing fibers having an average length within a range of from 1.6 mm to about 10 mm, and more preferably from 1.6 mm to about 5 mm. The reinforcing fibers preferably have an average diameter within a range of from about 5 microns to about 30 microns, more preferably from about 10 microns to about 20 microns, and most preferably from about 13 microns to about 16 microns.

The reinforcing fibers can be included in the adhesive in any suitable amount. The amount of fiber used in the adhesive may be regulated so as to reduce any processing issues caused by too high a viscosity. In practice a level of less than about 50% by weight of fiber is preferred, preferably an amount within a range of from about 10 wt % to about 50 wt %, and more preferably from about 10 wt % to about 30 wt %. The amount of fiber and the other aspects of the invention impart the desired bond strength improvement without unduly affecting the processing properties of the adhesive.

In contrast to many adhesives known in the art, the adhesive of the invention can usually be made without a substantial amount of solvent. Preferably, the adhesive contains not more than about 5 wt % solvent, and more preferably it contains substantially no solvent.

In another embodiment, the adhesive of the invention can be made by mixing a reinforced asphalt material with a filled asphalt material to produce the adhesive. The reinforced asphalt material comprises a first asphalt material and reinforcing fibers dispersed in the first asphalt material. The filled asphalt material comprises a second asphalt material and roofing filler dispersed in the second asphalt material. The first and second asphalt materials may be any of those described above, and they may be the same or different from each other. The reinforcing fibers and the roofing filler may also be any of those described above. The reinforce asphalt material may further include a polymer such as any of those described above.

In accordance with the provisions of the patent statutes, the principle and mode of operation of this invention have been described in its preferred embodiments. However, it must be understood that this invention may be practiced otherwise than as specifically described without departing from its spirit or scope.

Claims

1. An adhesive for a roofing material comprising an asphalt material and reinforcing fibers dispersed in the asphalt material, the reinforcing fibers having an average length within a range of from 1.6 mm to about 10 mm, the adhesive being capable of adhesively bonding a first asphalt-based roofing material to a second asphalt-based roofing material or to a roof, and the adhesive being processable with conventional adhesive manufacturing equipment.

2. The adhesive defined in claim 1 wherein the adhesive has a viscosity within a range of from about 500 cps to about 2000 cps at 350° F. (217° C.).

3. The adhesive defined in claim 1 wherein the reinforcing fibers are included in an amount within a range of from about 10 wt % to about 50 wt %.

4. The adhesive defined in claim 1 wherein the reinforcing fibers have an average diameter within a range of from about 10 microns to about 20 microns.

5. The adhesive defined in claim 1 wherein the asphalt material comprises an oxidized asphalt having a softening point of at least about 150° F. (66° C.).

6. The adhesive defined in claim 1 wherein the adhesive contains not more than about 5 wt % solvent.

7. The adhesive defined in claim 1 wherein the asphalt material comprises an oxidized asphalt having a softening point of at least about 150° F. (66° C.), the reinforcing fibers are included in an amount within a range of from about 10 wt % to about 30 wt %, and the reinforcing fibers have an average length within a range of from 1.6 mm to about 5 mm.

8. The adhesive defined in claim 1 which further comprises a polymer mixed with the asphalt material to produce a polymer modified asphalt.

9. The adhesive defined in claim 8 wherein the polymer modified asphalt has a softening point within a range of from about 170° F. (77° C.) to about 220° F. (104° C.).

10. The adhesive defined in claim 8 wherein the polymer comprises a styrenic elastomer.

11. The adhesive defined in claim 8 wherein the reinforcing fibers are included in an amount within a range of from 10 wt % to about 50 wt %.

12. The adhesive defined in claim 8 wherein the polymer comprises a styrenic elastomer, the polymer modified asphalt has a softening point within a range of from about 170° F. (77° C.) to about 220° F. (104° C.), the reinforcing fibers are included in an amount within a range of from about 10 wt % to about 30 wt %, and the reinforcing fibers have an average length within a range of from 1.6 mm to about 5 mm.

13. The adhesive defined in claim 12 wherein the reinforcing fibers comprise glass fibers.

14. The adhesive defined in claim 1, wherein the roofing material comprises a reinforcement member, the reinforcement member defining a nail zone of the roofing material.

15. The adhesive defined in claim 1 which is used for bonding a reinforcement member to a roofing shingle, where the reinforcement member defines a nail zone of the shingle.

16. The adhesive as defined in claim 1, wherein the adhesive comprises a laminate adhesive.

17. The adhesive as defined in claim 1, wherein the adhesive comprises a sealant.

18. An adhesive for a roofing material comprising an asphalt material, reinforcing fibers dispersed in the asphalt material, and roofing filler dispersed in the asphalt material, the adhesive being capable of adhesively bonding a first asphalt-based roofing material to a second asphalt-based roofing material or to a roof, and the adhesive being processable with conventional adhesive manufacturing equipment.

19. The adhesive defined in claim 18 wherein the roofing filler is included in an amount within a range of from 20 wt % to about 70 wt %.

20. The adhesive defined in claim 18 wherein the reinforcing fibers have an average length within a range of from 1.6 mm to about 10 mm.

21. The adhesive defined in claim 18 wherein the adhesive has a viscosity within a range of from about 500 cps to about 2000 cps at 350° F. (217° C.).

22. The adhesive defined in claim 18 wherein the reinforcing fibers are included in an amount within a range of from 10 wt % to about 50 wt %.

23. The adhesive defined in claim 18 which further comprises a polymer mixed with the asphalt material to produce a polymer modified asphalt.

24. The adhesive defined in claim 18 which is used for bonding a reinforcement member to a roofing shingle, where the reinforcement member defines a nail zone of the shingle.

25. A roofing assembly comprising a first asphalt-based roofing material and an adhesive which is capable of adhesively bonding the first roofing material to a second asphalt-based roofing material or to a roof, the adhesive comprising an asphalt material and reinforcing fibers dispersed in the asphalt material, the reinforcing fibers having an average length within a range of from 1.6 mm to about 10 mm, the adhesive being processable with conventional adhesive manufacturing equipment.

26. The roof assembly defined in claim 25 wherein the adhesive further comprises a polymer mixed with the asphalt material to produce a polymer modified asphalt.

27. A method of manufacturing an adhesive for a roofing material comprising mixing a reinforced asphalt material with a filled asphalt material to produce the adhesive, the reinforced asphalt material comprising a first asphalt material and reinforcing fibers dispersed in the first asphalt material, the filled asphalt material comprising a second asphalt material and roofing filler dispersed in the second asphalt material, the adhesive being capable of adhesively bonding a first asphalt-based roofing material to a second asphalt-based roofing material or to a roof, and the adhesive being processable with conventional adhesive manufacturing equipment.

28. The method defined in claim 27 wherein the reinforced asphalt material further comprises a polymer.