WO1999054420A1

WO1999054420A1 - Improved pressure-sensitive roofing tape

Info

Publication number: WO1999054420A1
Application number: PCT/US1999/008206
Authority: WO
Inventors: Daniel John COTSAKIS
Original assignee: Carlisle Companies Incorporated
Priority date: 1998-04-17
Filing date: 1999-04-15
Publication date: 1999-10-28

Abstract

A pressure sensitive roofing tape (10) composed of a transparent polymeric release liner (12) and a brominated butyl rubber-EPDM adhesive layer (18) is disclosed. The adhesive layer (18) includes a plasticizer, a phenolic tackifier and non-phenolic tackifiers that provide resiliency and permanent tack at low temperatures. The transparent polymeric release liner (12) aids in the placement of the roofing tape (10) and is better able to withstand harsh job-site conditions than conventional paper release liners.

Description

IMPROVED PRESSURE-SENSITIVE ROOFING TAPE

BACKGROUND OF THE INVENTION

Technical Field

The present invention relates generally to adhesive materials used to join roofing membranes and, more particularly, to splicing tapes that remain tacky after they are substantially cured.

Discussion

Rubber membrane roofing materials are flat sheets of either single-ply or multiple-ply polymeric materials such as ethylene propylene diene terpolymer (EPDM) or isoprene isobutylene copolymer. These sheets are typically provided in large rolls of standard widths. After a section of sheeting material is applied to a roof surface, a second section is laid down partially overlapping the first section. This overlap is critical to ensure that a gap is not created between the sheet since a gap would allow water to penetrate the roof surface.

In order to create a water-tight seal between adjacent overlapping roofing sheets, it is necessary to provide a water-tight bond at the splice or lap joint. This is generally achieved by interposing an adhesive between the two roofing sheets at the region of overlap. The surfaces to be bonded together may be cleaned prior to application of the adhesive using a solvent or the like to enhance the bonding process; a primer may be applied to the cleaned surfaces to further increase the bond strength of the adhesive. In some applications a liquid contact adhesive is applied to one or more of the roofing sheets at the lap joint and is allowed to dry. The sheets are then overlapped and pressure is applied to cause the contact adhesive to bond the two sheets together. After the two sheets are joined in this manner, a caulking material may be used along the edge of the top layer at the joint and/or internal to the lap joint to provide additional protection against water intrusion.

-1— Another technique for joining two sheets of roofing material involves the use of adhesive roofing tapes, which are designed to take the place of liquid roofing adhesives. Conventional tapes are available as rolls having a paper release liner separating adjacent adhesive layers. To seal roofing sheets at the lap joint, the installer unrolls a length of the tape and places it — release liner facing up — along the edge of the roofing sheet that comprises the lower member of the lap joint. The installer removes the paper release liner, and then places the roofing sheet that constitutes the upper member of the lap joint on top of the adhesive layer. Finally, the installer applies pressure to the lap joint to create a water-tight seal. In this way, the adhesive layer is interposed between the overlapping surfaces of the roofing sheets along the entire length of the lap joint.

There are a number of important requirements for quality adhesive roofing tapes. For example, they must provide a water-tight bond at the lap joint. In addition, they must resist environmental degradation for many years; a premature failure of the adhesive layer can result in extensive water damage. It is important that the adhesive layer also retain some flexibility so that the lap joint does not fail as a result of thermal expansion and contraction of the roofing sheets. Roofing tapes addressing these requirements were recently disclosed in U.S. Pat. Nos. 5,686,179 and 5,733,621, which are herein incorporated by reference. Because of difficulties involved in meeting the sealing requirements of roofing tapes, most development efforts have focused on improving the performance of the adhesive layer. Researchers have thus expended comparatively little effort at remedying problems associated with the use of paper release liners, even though these problems can impact tape performance. For example, when using tapes with conventional paper release liners, roof installers often have difficulty accurately placing the tape along the lap joint. This difficulty arises because conventional release liners are opaque, and the edge of the tape is normally recessed an eighth of an inch or more from the edge of the release liner. In addition, paper release liners are easily spoiled by job site conditions: they can dry out and become brittle when stored in high heat conditions, or can be ruined

—2— when exposed to high humidity or wet weather. Furthermore, paper release liners easily tear during tape unrolling or liner removal prior to tape installation.

The present invention is directed to overcoming, or at least minimizing, one or more of the problems set forth above.

SUMMARY OF THE INVENTION

In accordance with one aspect of the present invention, there is provided a pressure sensitive roofing tape that is used to seal lap joints formed by overlapping adjoining roofing membranes. The roofing tape comprises a flexible polymeric release liner disposed on an adhesive layer.

In accordance with a second aspect of the present invention, there is provided a pressure sensitive roofing tape comprising a release liner disposed on an adhesive layer. The release liner is composed of a flexible polymeric film, and the adhesive layer is composed of a mixture of brominated isoprene isobutylene copolymer, ethylene propylene diene teφolymer, polyisobutylene plasticizer, thermoplastic phenolic resin tackifier, thermoplastic non-phenolic hydrocarbon resin tackifier, and a peroxide curing agent. The roofing tape is used to seal lap joints formed by overlapping adjoining roofing membranes. In accordance with a third aspect of the present invention, there is provided a pressure sensitive roofing tape comprising a transparent release liner, which is composed of a flexible polymeric film, disposed on an adhesive layer. The adhesive layer comprises, in approximate weight percent, from 10 to 30 percent brominated isoprene isobutylene copolymer, from 5 to 20 percent ethylene propylene diene teφolymer, up to 5 percent styrene ethylene-butylene block teφolymer, from 1 to 10 percent carbon black, from 0.1 to 2 percent multifunctional acrylic monomer, up to 3 percent reactive metal oxide filler, from 25 to 50 percent polyisobutylene plasticizer, from 5 to 15 percent thermoplastic phenolic resin tackifier, from 5 to 15 percent high melting point thermoplastic non-phenolic hydrocarbon resin tackifier, from 1 to 15 percent low melting point thermoplastic non-phenolic hydrocarbon resin tackifier, and

—3— from 0.1 to 2 percent peroxide curing agent. The roofing tape is used to seal lap joints formed by overlapping adjoining roofing membranes.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing and other advantages of the invention will become apparent upon reading the following detailed description and upon reference to the drawings in which:

Fig. 1 is a perspective view of a roofing tape. Fig. 2 is a cross-section of two roofing membranes that are bonded together by a roofing tape of the present invention.

Fig. 3 is a flow charting illustrating a method of forming a pressure sensitive adhesive roofing tape.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring now to the drawings, Fig. 1 shows a perspective view of a roll of roofing tape 10. The roofing tape 10 comprises a transparent release liner 12 having a top surface 14 and a bottom surface 16, and an adhesive layer 18 having a top surface 20 and a bottom surface 22. The bottom surface 16 of the release liner 12 is disposed on the top surface 20 of the adhesive layer 18.

The release liner can be made of any tough, flexible film that can withstand temperatures associated with curing the adhesive layer. In addition, it is desirable that the release liner be transparent. Suitable release liners can be made from organic polymers including polyethylene, polypropylene, polyester, fluorinated ethylene- propylene copolymer (FEP), polyamide and polyamideimide. Release liners made from poly(ethylene terephthalate) or PET, are especially useful when the adhesive layer is cured at relatively high temperatures. For example, adhesive tape formulations disclosed in U.S. Pat. Nos. 5,686,179 and 5,733,621 are partially cured at temperatures between about 145°C and 175°C for about 1 to 3 minutes, and then completely cured at temperatures between about 110°C and 140°C for about 3 to 24 hours.

Typically, the top and bottom surfaces of the release liner are treated to provide differential adhesion to the adhesive layer. For example, referring to the roofing tape 10 of Fig. 1, the release liner 12 can be treated so that the adhesive strength between the bottom surface 16 of the release liner 12 and the top surface 20 of the adhesive layer 18 is substantially greater than the adhesive strength between the top surface 14 of the release liner 12 and the bottom surface 22 of the adhesive layer 18. In this way, the roofing tape 10 can be unrolled with minimal "jump across" — adhesion of the bottom surface 22 of the adhesive layer 18 to the top surface 14 of the release liner 12.

Various techniques can be used to create differential adhesion to the release liner. One method is to apply a coating to one surface of the release liner, or different coatings to both surfaces. The coating or coatings may either promote or inhibit adhesion to the adhesive liner. For example, coating the bottom surface of a polyester release liner with a solvent-dispersed silicone results in relatively good adhesion to a bromobutyl rubber — EPDM adhesive layer; however, coating the top surface of the release liner with a 100 percent solids silicone results in relatively poor adhesion. Adding a contaminant, such as an olefin, to one side of a silicone treated polyester release liner improves the adhesion of that side to a bromobutyl rubber — EPDM adhesive layer. If the polymeric film adheres poorly to the adhesive layer, as is the case with FEP film, the bottom surface of the release liner can be physically or chemically etched to promote adhesion.

Fig. 2 shows a cross-sectional view (not to scale) of two roofing membranes that are bonded together using the roofing tape of the present invention. A lap joint 30 is formed by overlapping upper 32 and lower 34 roofing membranes. Various materials can be used to form roofing membranes including EPDM rubber, which is durable and impervious to water. To seal the upper 32 and lower 34 roofing membranes at the lap joint 30, the installer unrolls a length of roofing tape (not shown) and places it — release liner facing up — along an edge 36 of the lower roofing

—5— membrane 34. The installer removes the release liner, leaving behind an adhesive layer 38. The installer then places the upper roofing membrane 32 over the adhesive layer 38, and applies pressure to the lap joint 30 to create a water-tight seal. In this way, the adhesive layer 38 is inteφosed between the overlapping upper 32 and lower 34 roofing membranes along the entire length of the lap joint 30.

The adhesive layer must provide a water-tight bond at the lap joint. It should also resist environmental degradation for many years, and retain some flexibility so that the lap joint does not fail as a result of thermal expansion and contraction of the roofing membranes. One particularly useful adhesive is comprised of a covulcanized mixture of brominated butyl rubber and ethylene propylene diene teφolymer (EPDM). The adhesive includes a significant portion of a high molecular weight plasticizer. The plasticizer increases resiliency without migrating into the adjoining roofing membranes; such "bleed through" is common in adhesives that rely on low molecular weight tackifiers. Surface tack is provided through the addition of a thermoplastic phenolic resin tackifier and a thermoplastic non-phenolic resin tackifier. Because of the presence of the high-molecular weight plasticizer, relatively small amounts of these tackifiers are used, which further reduces bleed through of the tackifiers. Where high tack values are required in low temperature applications, the thermoplastic non-phenolic hydrocarbon resin tackifier component comprises a high melting point resin or resins and a low melting point resin or resins.

The disclosed adhesive uses a peroxide curing agent which, in combination with the halogenated butyl rubber component, permits rapid cross-linking without a concomitant rapid degradation of the brominated butyl rubber (vs. a non-halogenated butyl rubber). The use of a high molecular weight plasticizer, a peroxide curing agent and a halogenated butyl rubber allows some limited degradation of the plasticizer that contributes to surface tack.

Cure characteristics of the adhesive layer can be improved through the use of various additives. These include one or more metal oxide reactive fillers such as magnesium oxide, calcium oxide, and zinc oxide. Other useful additives include

-6— multifunctional acrylic monomers, such as trimethylolpropane trimethylacrylate (TMPTMA). TMPTMA and similar compounds can be used by themselves, or can be used in conjunction with one or more of the reactive fillers.

Styrene ethylene-butylene block teφolymer can be added as a processing aid. The block teφolymer enhances the thermoplastic properties of the adhesive mixtures without affecting the structure of the brominated butyl rubber — EPDM cross-linked network. In addition, carbon black can be added as a filler, colorant, ultraviolet light absorber and reinforcing agent.

Fig. 3 illustrates a method of making a pressure sensitive adhesive roofing tape. The method describes the manufacture of a roofing tape having a brominated butyl rubber — EPDM based adhesive layer. However, roofing tapes having other adhesive layer compositions can be made in a similar manner.

As shown in Fig. 3, brominated isoprene isobutylene copolymer and ethylene propylene diene teφolymer are provided at step 52. If desired, styrene ethylene- butylene block teφolymer, TMPTMA, magnesium oxide and carbon black can also be provided at step 52. Although the use of brominated isoprene isobutylene copolymer is disclosed, other halogenated isoprene isobutylene copolymers, such as chlorinated butyl rubber, can be used.

One suitable brominated butyl rubber is sold under the trade name BROMOBUTYL 2030 by Bayer, Inc. As will be appreciated by those skilled in the art, the isoprene units comprise about 3 % of the bromobutyl polymer. The bromobutyl polymer contains about 2 % bromine by weight, with all the bromine attached to the isoprene units. Particularly useful brominated isoprene isobutylene copolymers have a Mooney viscosity from about 27 to about 51 ML 1 + 8 (125°C) and a number average molecular weight from about 300,000 to about 450,000.

Ethylene propylene diene teφolymer is also provided at step 52. One suitable EPDM rubber can be obtained from Uniroyal under the trade name ROYALENE 3275B. Generally, EPDM teφolymers having ethylene to propylene ratios of 80/20 to 50/50, number average molecular weights of 100,000 to 280,000, and contain either ethylidene norbornene, 1,4-hexadiene or dicyclopentadiene as the diene. However, it

—7- is preferred that the ethylene propylene diene teφolymer have a number average molecular weight of from about 180,000 to about 220,000, have an ethylene to propylene ratio of 58/42, and contain ethylidene norbornene as the diene.

A non-diene block teφolymer such as styrene-ethylene butylene block teφolymer can also be included in the polymer mixture. It increases the thermoplastic characteristics of the base polymer mix which impacts processability and the dynamic thermal characteristics of tape in the field. Other non-diene block teφolymers can be used such as styrene butadiene block teφolymers, styrene isoprene block teφolymers and vinyl acetate-ethylene copolymers. A particularly useful styrene ethylene-butylene block teφolymer is sold under the trade name KRATON G1657 by the Shell

Chemical Company. It is preferred that the styrene ethylene-butylene block teφolymer have a number average number molecular weight of from about 40,000 to about 250,000 and a styrene to ethylene-butylene ratio of about 13/87.

In addition to the foregoing components, other additives can be provided at step 52. These additives include one or more metal oxide reactive fillers such as magnesium oxide, multifunctional acrylic monomers such as TMPTMA, and one or more inert fillers such as carbon black. A suitable TMPTMA is available from Sartomer under the trade name SARET 517. Other inert fillers can be also provided at step 52, either to replace or to supplement carbon black. These inert fillers include clays, silicates, calcium carbonate, precipitated or fumed silicas, ground coal or other additives to impart flame retardant properties. Fibers or fabric can also be incoφorated into the adhesive layer at step 52 to obtain certain physical properties.

Referring again to Fig. 3 of the drawings, the brominated isoprene isobutylene copolymer, ethylene propylene diene teφolymer, styrene-ethylene butylene block teφolymer and additives are combined in a batch mixer at step 54. A conventional Banbury-type intensive batch mixer can be used to mix and blend the components from step 52 to form a rubbery mass. At step 56, the resulting mass is cut or ground into a usable particle size using a conventional rubber chopper. The equipment used and the resulting particle size are conventional and are commonly known in the art.

—8— The resulting base polymer mix is fed to a screw-type continuous mixer, preferably a twin screw mixer, at step 58.

Additional components are added in stages to the base polymer as it moves through the continuous mixer at step 58. Tackifiers, high molecular weight plasticizer, and peroxide curing agent are added at steps 60, 62, and 64, respectively, through ports in the side of the screw mixer at different distances or stages along the barrel. Because the adhesive compound contains a relativley large volume of plasticizer, the plasticizer is generally added in multiple stages along the length of the mixer barrel. Tackifiers preferably include a mixture of a thermoplastic phenolic resin tackifier and a non-phenolic thermoplastic hydrocarbon resin tackifier. Suitable thermoplastic phenolic resin tackifiers are non-heat reactive phenol-novolac resins having an average ring and ball melting point of from about 70°C to about 120°C; normally, the thermoplastic phenolic resin tackifier will have an average ring and ball melting point of from about 85°C to about 110°C. The latter tackifiers are available from Schenectady Chemicals, Inc. under the trade names SP-1068 and SP-1077. Suitable non-phenolic hydrocarbon thermoplastic resin tackifiers include "high" and "low" melting point polycyclic aliphatic hydrocarbon resins having slight to no unsaturation. "High" melting point tackifiers are those having an average ring and ball melting point of about 70°C to about 140°C; "low" melting point tackifiers are those having an average ring and ball melting point less than about 25°C.

Especially useful high melting point non-phenolic tackifiers have a ring and ball melting point of about 85°C to about 110°C. Such tackifiers are available from Exxon Chemical Company under the trade names ESCOREZ 1310 and ESCOREZ 5300, and from Hercules, Inc. under the trade name PICCOPALE 100. The addition of a low melting point non-phenolic hydrocarbon thermoplastic resin tackifier can improve low temperature tack. Suitable low melting point tackifiers have number average molecular weights between about 600 and 2500. Especially useful low melting point tackifiers have number average molecular weights between about 600 and 900, and Brookfield viscosities, at 25°C, between about 20,000 and 60,000 cps. Such tackifiers are available under the trade names WINGTACK 10,

-9— ADTAC LV and REGALREZ 1018. The most preferred low melting point non- phenolic thermoplastic hydrocarbon resin tackifier for use herein is sold as WINGTACK 10 by Goodyear Chemical.

A particularly useful combination of phenolic resin tackifiers and high and low melting point non-phenolic hydrocarbon resin tackifiers is a mixture of SP-1068, which is available from Schenectady Chemicals, Inc., ESCOREZ 1310, which is available from Exxon Chemical Company, and WINGTACK 10, which is available from Goodyear Chemical.

It is important to include a high molecular weight plasticizer such as a polyisobutylene plasticizer having a number average molecular weight between about 2,000 and 65,000, or more preferably, between about 2,050 and about 2,500. Other suitable high molecular weight plasticizers include INDOPOL H-1500, VISTANEX LM-MS and VISTANEX LM-MH. An especially useful polyisobutylene plasticizer is available from Amoco under the trade name INDOPOL H-1900. A number of peroxide curing agents can be used to crosslink the brominated butyl rubber and EPDM rubber including dicumyl peroxide, l,l-di-(tertbutylperoxy)- 3,3,5-trimethylcylohexane and other diacyl and dialkyl peroxides and peroxyketals. A suitable dicumyl peroxide is available from Hercules, Inc. under the trade name DICUP 40C, and a suitable l,l-di-(tertbutylperoxy)-3,3,5-trimethylcylohexane curing agent is available from AkzoNobel under the trade name TRIGONOX 29. It will be appreciated that commercial preparations of peroxide curing agents typically include a carrier such as calcium carbonate. In all of the formulations disclosed below, the concentration of the peroxide curing agent does not include any contribution from the carrier. The peroxide curing agent, in combination with the halogenated butyl rubber component, permits rapid cross-linking without a concomitant rapid degradation of the brominated butyl rubber. The use of a high molecular weight plasticizer, a peroxide curing agent and a halogenated butyl rubber allows some limited degradation of the plasticizer which contributes to surface tack.

_10— Depending on the raw material feed rates and screw speed of the twin screw continuous mixer, complete mixing will generally be completed in from about 1 to about 4 minutes; it is important that the components be well-blended prior to extrusion. Referring again to Fig. 3 of the drawings, the adhesive compound is extruded with a single screw extruder through a conventional tape-form die to conveyor-fed, polymeric release liner at step 68. At step 70, the resulting uncured adhesive layer is partially cured in an in-line curing oven at a temperature between about 145°C to about 175°C for approximately 1 to 3 minutes (i.e., the residence time of the tape in the oven). The partially cured adhesive layer on the release liner is then rolled onto a tape core at step 72. In order to finish the cure, the rolled tape is placed in a final cure oven at about 110°C to about 140°C for approximately 3 to 24 hours at step 74. The final tape product is substantially cured.

A person of ordinary skill in the art will realize that the amounts of each component comprising the adhesive layer can be adjusted to meet various tape performance requirements. These requirements often include high and low temperature tensile strength, elongation, modulus, adhesive strength, and tack. A brominated butyl rubber — EPDM adhesive layer suitable for use with the disclosed polymeric release liner, and capable of meeting a broad range of performance requirements is disclosed in Table 1.

Table 1.

Component Approximate Wt. % brominated isoprene isobutylene copolymer 10 — 30 ethylene propylene diene teφolymer 5 — 20 styrene ethylene-butylene block teφolymer 0 — 5 carbon black 1 — 10 multifunctional acrylic monomer 0.1 — 2 reactive metal oxide filler 0 — 3 polyisobutylene plasticizer 25 — 50

-11- thermoplastic phenolic resin tackifier 5 — 15 high melting point thermoplastic non-phenolic 5 — 15 hydrocarbon resin tackifier low melting point thermoplastic non-phenolic 1 — 15 hydrocarbon resin tackifier peroxide curing agent 0.1 — 2

EXAMPLES

The following examples are intended as illustrative and non-limiting, and represent specific embodiments of the present invention.

Various silicone-coated PET films were tested for use as release liners with a brominated butyl rubber — EPDM adhesive layer. The adhesive layer was comprised of a mixture of brominated isoprene isobutylene copolymer, EPDM, carbon black, TMPTMA, MgO, polyisobutylene plasticizer, thermoplastic phenolic resin tackifier, high and low melting point thermoplastic non-phenolic hydrocarbon resin tackifers, and l,l-di-(tertbutylperoxy)-3,3,5-trimethylcyclohexane. Results from the test are shown in Table 2. Silicone-coated PET films from 4P Folie Forchheim performed the best as release liners.

It is to be understood that the above description is intended to be illustrative and not restrictive. Many embodiments will be apparent to those of skill in the art upon reading the above description. The scope of the invention should, therefore, be determined not with reference to the above description, but should instead be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled. The disclosures of all articles and references, including patent applications and publications, are incoφorated herein by reference for all puφoses.

-12- Table 2.

Supplier Film Designation Thickness Silicone Coating Results mils 5 4-i. *-

Akrosil NAT PET H 1 K/H2J 5.0 100% solids, UV cure Silicone coating rub-off & o transfer

NAT PET H1K/H2J 3.0 100% solids, UV cure Silicone coating rub-off & transfer

NAT PET H1D/H2A 3.0 100% solids, UV cure Silicone coating rub-off & transfer

NAT PET H2S/E-886 2.0 100% solids, UV cure Silicone coating rub-off & transfer

NAT PET H1H/H2A 2.0 100% solids, UV cure Silicone coating rub-off & transfer

Daubert Coated 2-PESTR(P2) 8000A&8250A 5.0 100% solids, Thermal Cure, Pt Silicone rub-off Products Catalyzed

Unknown PET 2.0 100% solids, Thermal Cure, Sn Silicone coating rub-off &

Catalyzed transfer

2-PESTR(P2) 8000A&8250A 3.0 100% solids, Thermal Cure, Pt Silicone coating transfer after roll n H

Catalyzed aging

©

00 o

Supplier Film Designation Thickness Silicone Coating Results mils

2-PESTR(P2) 9500A&8225A 3.0 100% solids, Thermal Cure, Pt Silicone rub-off ϋi κ>

Catalyzed o

2-PESTR(NAT) 8000A&8250A 3.0 100% solids, Thermal Cure, Pt Silicone coating transfer after roll

Catalyzed aging

2-PESTR(NAT) 9500A&8225A 3.0 100% solids, Thermal Cure, Pt Silicone coating transfer after roll

Catalyzed aging

4P Folie Type 1876 PET 1710/1803 1.5 100% solids, Thermal Cure, Pt OK Forchheim Catalyzed (Bottom)

-ρ=» I Solvent Based, Thermal Cure Pt

Catalyzed (Top)

Type 1876 PET 1710/1803 5.0 100% solids, Thermal Cure, Pt OK

Catalyzed (Bottom)

Solvent Based, Thermal Cure Pt

Catalyzed (Top)

Type 1876 PET 1710/1803 3.0 100% solids, Thermal Cure, Pt OK

Catalyzed (Bottom) -o o

H

Solvent Based, Thermal Cure Pt

00 o

Supplier Film Designation Thickness Silicone Coating Results

3? mils O

Catalyzed (Top) t/i

*^- to

Type 1876 PET 1710/1803 2.0 100% solids, Thermal Cure, Pt OK © Catalyzed (Bottom) Solvent Based, Thermal Cure Pt Catalyzed (Top)

Type 1876 PET 9716/1932 3.0 100% solids, thermal cure, Pt Silicone coating rub-off & Catalyzed transfer

Type 1876 PET 9702/9741 3.0 100% solids, thermal cure, Pt OK en Catalyzed

Type 1874 PET 9702/9741 3.0 100% solids, thermal cure, Pt Silicone coating rub-off Catalyzed

Rexam Release #131 13 S PET 18C/27G 2.0 100% solids, EB cure Tape cured tight to release liner (lock-up)

#13371 S PET 85A/86B 3.0 100% solids, UV cure Silicone coating transfer

Siliconature PET BISC 1.5 Unknown Silicone coating rub-off

PET BISC 2.0 Unknown Silicone coating rub-off n -o

Technicote PET L-3/L-10X 3.0 Unknown Silicone coating rub-off tZ⁾

o

00

©

Claims

CLAIMSWHAT IS CLAIMED IS:

1. A pressure sensitive roofing tape, comprising: an adhesive layer having a top surface and a bottom surface, and a release liner having a top surface and a bottom surface, the bottom surface of the release liner disposed on the top surface of the adhesive layer; wherein the release liner is comprised of a flexible polymeric film, and the roofing tape is used to seal lap joints formed by overlapping adjoining roofing membranes.

2. The pressure sensitive roofing tape of claim 1, wherein the release liner is transparent.

3. The pressure sensitive roofing tape of claim 1 , wherein the top surface and the bottom surface of the release liner have been treated to provide differential adhesion to the adhesive layer so that the adhesive strength between the bottom surface of the release liner and the top surface of the adhesive layer is substantially greater than the adhesive strength between the top surface of the release liner and the bottom surface of the adhesive layer when the roofing tape is produced in roll form.

4. The pressure sensitive roofing tape of claim 1 further comprising: a first coating, and a second coating, the first coating applied to the top surface of the release liner and the second coating applied to the bottom surface of the release liner so that the adhesive strength between the bottom surface of the release liner and the top surface of the adhesive layer is substantially greater than the adhesive strength between the top surface of the release liner and the bottom surface of the adhesive layer when the roofing tape is produced in roll form.

ΓÇö16ΓÇö

5. The pressure sensitive roofing tape of claim 4, wherein the first coating and the second coating are silicone coatings.

6. The pressure sensitive roofing tape of claim 1, wherein the polymeric film is polyethylene, polypropylene, polyester, fluorinated ethylene-propylene copolymer, polyamide or polyamideimide.

7. The pressure sensitive roofing tape of claim 6, wherein the polyester is poly(ethylene terephthalate).

8. The pressure sensitive roofing tape of claim 1 , wherein the adhesive layer comprises: brominated isoprene isobutylene copolymer, ethylene propylene diene te╧åolymer, polyisobutylene plasticizer, thermoplastic phenolic resin tackifier, thermoplastic non-phenolic hydrocarbon resin tackifier, and peroxide curing agent.

9. The pressure sensitive roofing tape of claim 8, the adhesive layer further comprising a multifunctional acrylic monomer.

10. The pressure sensitive roofing tape of claim 9, wherein the multifunctional acrylic monomer is trimethylolpropane trimethylacrylate.

11. The pressure sensitive roofing tape of claim 8, the adhesive layer further comprising a reactive metal oxide filler.

12. The pressure sensitive roofing tape of claim 11, wherein the reactive metal oxide filler is ZnO, MgO, or CaO, alone or in combination.

13. The pressure sensitive roofing tape of claim 8, wherein the peroxide curing agent is l,l-di-(tertbutyl╧üeroxy)-3,3,5-trimethylcylohexane or dicumyl peroxide, alone or in combination.

14. The pressure sensitive roofing tape of claim 8, the adhesive layer further comprising: trimethylolpropane trimethylacrylate, and magnesium oxide;

ΓÇö17ΓÇö wherein the peroxide curing agent is l,l-di-(tertbutylperoxy)-3,3,5- trimethylcylohexane or dicumyl peroxide, alone or in combination.

15. The pressure sensitive roofing tape of claim 8, wherein the thermoplastic non-phenolic hydrocarbon resin tackifier comprises: a high melting point thermoplastic non-phenolic hydrocarbon resin tackifier, and a low melting point thermoplastic non-phenolic hydrocarbon resin tackifier.

16. The pressure sensitive roofing tape of claim 8, the adhesive layer further comprising carbon black.

17. The pressure sensitive roofing tape of claim 8, the adhesive layer further comprising styrene ethylene-butylene block te╧åolymer.

18. A pressure sensitive roofing tape, comprising: an adhesive layer having a top surface and a bottom surface, and a release liner having a top surface and a bottom surface, the bottom surface of the release liner disposed on the top surface of the adhesive layer; wherein the adhesive layer comprises: brominated isoprene isobutylene copolymer, ethylene propylene diene te╧åolymer, polyisobutylene plasticizer, thermoplastic phenolic resin tackifier, thermoplastic non-phenolic hydrocarbon resin tackifier, and peroxide curing agent; and wherein the release liner is comprised of a flexible polymeric film, and the roofing tape is used to seal lap joints formed by overlapping adjoining roofing membranes.

19. The pressure sensitive roofing tape of claim 18, wherein the release liner is transparent.

ΓÇö18-

20. The pressure sensitive roofing tape of claim 18, wherein the top surface and the bottom surface of the release liner have been treated to provide differential adhesion to the adhesive layer so that the adhesive strength between the bottom surface of the release liner and the top surface of the adhesive layer is substantially greater than the adhesive strength between the top surface of the release liner and the bottom surface of the adhesive layer when the roofing tape is produced in roll form.

21. The pressure sensitive roofing tape of claim 18 further comprising: a first coating, and a second coating, the first coating applied to the top surface of the release liner and the second coating applied to the bottom surface of the release liner so that the adhesive strength between the bottom surface of the release liner and the top surface of the adhesive layer is substantially greater than the adhesive strength between the top surface of the release liner and the bottom surface of the adhesive layer when the roofing tape is produced in roll form.

22. The pressure sensitive roofing tape of claim 21 , wherein the first coating and the second coating are silicone coatings.

23. The pressure sensitive roofing tape of claim 18, wherein the polymeric film is polyethylene, polypropylene, polyester, fluorinated ethylene-propylene copolymer, polyamide or polyamideimide.

24. The pressure sensitive roofing tape of claim 23, wherein the polyester is poly(ethylene terephthalate).

25. A pressure sensitive roofing tape, comprising: an adhesive layer having a top surface and a bottom surface, and a transparent release liner having a top surface and a bottom surface, the bottom surface of the release liner disposed on the top surface of the adhesive layer; wherein the release liner is comprised of a flexible polymeric film, and the adhesive layer comprises:

-19- from about 10 to about 30 percent by weight brominated isoprene isobutylene copolymer, from about 5 to about 20 percent by weight ethylene propylene diene te╧åolymer, up to about 5 percent by weight styrene ethylene-butylene block te╧åolymer, from about 1 to about 10 percent by weight carbon black, from about 0.1 to about 2 percent by weight multifunctional acrylic monomer, up to about 3 percent by weight reactive metal oxide filler, from about 25 to about 50 percent by weight polyisobutylene plasticizer, from about 5 to about 15 percent by weight thermoplastic phenolic resin tackifier, from about 5 to about 15 percent by weight high melting point thermoplastic non-phenolic hydrocarbon resin tackifier, from about 1 to about 15 percent by weight low melting point thermoplastic non-phenolic hydrocarbon resin tackifier, from about 0.1 to about 2 percent by weight peroxide curing agent; wherein the roofing tape is used to seal lap joints formed by overlapping adjoining roofing membranes.

26. The pressure sensitive roofing tape of claim 25, wherein the multifunctional acrylic monomer is trimethylolpropane trimethylacrylate.

27. The pressure sensitive roofing tape of claim 25, wherein the reactive metal oxide filler is ZnO, MgO, or CaO, alone or in combination.

28. The pressure sensitive roofing tape of claim 25, wherein the peroxide curing agent is l,l-di-(tertbutylperoxy)-3,3,5-trimethylcylohexane or dicumyl peroxide, alone or in combination.

29. The pressure sensitive roofing tape of claim 25, the adhesive layer further comprising:

-20ΓÇö trimethylolpropane trimethylacrylate, and magnesium oxide; wherein the peroxide curing agent is l,l-di-(tertbutylperoxy)-3,3,5- trimethylcylohexane or dicumyl peroxide, alone or in combination.

30. The pressure sensitive roofing tape of claim 25, wherein the top surface and the bottom surface of the release liner have been treated to provide differential adhesion to the adhesive layer so that the adhesive strength between the bottom surface of the release liner and the top surface of the adhesive layer is substantially greater than the adhesive strength between the top surface of the release liner and the bottom surface of the adhesive layer when the roofing tape is produced in roll form.

31. The pressure sensitive roofing tape of claim 25 further comprising: a first coating, and a second coating, the first coating applied to the top surface of the release liner and the second coating applied to the bottom surface of the release liner so that the adhesive strength between the bottom surface of the release liner and the top surface of the adhesive layer is substantially greater than the adhesive strength between the top surface of the release liner and the bottom surface of the adhesive layer when the roofing tape is produced in roll form.

32. The pressure sensitive roofing tape of claim 31 , wherein the first coating and the second coating are silicone coatings.

33. The pressure sensitive roofing tape of claim 25, wherein the polymeric film is polyethylene, polypropylene, polyester, fluorinated ethylene-propylene copolymer, polyamide or polyamideimide.

34. The pressure sensitive roofing tape of claim 33, wherein the polyester is poly (ethylene terephthalate).

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