POLYURETHANE BASED RIGID FLOORING LAMINATE

Abstract

The laminate according to the invention is a multiple layer structure and contains predominantly urethane-based polymeric materials in the cap and base layers thereof, with no significant amount of PVC. As such, under combustion conditions, the laminate releases substantially no harmful halogen-based bases, such as HCl or other toxic gases, and exhibits toxicity and smoke generation parameters well below acceptable industry standards.

Claims

1. A laminate structure comprising: a backing layer comprising, by weight, from about 20% to about 80% a fiber reinforcement and from about 80% to about 20% with a thermoset or thermoplastic polymer resin matrix; a base layer comprising an alloy layer made of polyurethane in combination with a terpolymer comprising polyamide, polyester and polyether or a combination thereof; and an adhesive layer disposed on a first surface of the base layer between the backing layer and the base layer; and a cap layer comprising polyurethane, wherein the peel resistance between the combination of the cap layer and base layer and the backing layer is at least about 103 Newtons (N) per 25 millimeters after aging for at least 500 hours.

2. The laminate of claim 1, wherein the laminate meets the toxicity flaming and non-flaming test protocols pursuant to AITM 2.0007 with respect to HCN, CO, NO.sub.2, SO.sub.2/H.sub.2S, HF, and HCl limits, said limits being less than 150, 1000, 100, 100, 100, and 150 respectively as measured by specific optical density, in addition to Federal Aviation Regulation 25.853 MD with regard to the parameters of vertical burn, drip time and char of the laminate, said limits being less than 15 seconds, 5 seconds and 203 mm respectively, and further having a tear strength of greater than 50 Newtons according to ISO 4674, method A, and an areal density of between 1800 and 2100 grams per square meter.

3. The laminate of claim 1, wherein the base layer includes the polyurethane/terpolymer as a sub layer in combination with at least one other sub layer selected from a primer sub layer, a fiber sub layer and a sealing sub layer.

4. The laminate of claim 3, wherein the fiber sub layer comprises at least one of glass, aramid, carbon, PVA, hemp, jute, organic fiber, synthetic fiber disposed in a thermoset or thermoplastic resin.

5. The laminate of claim 1, wherein the bondability between the combination of the cap layer and base layer and the backing layer is at least about 31 N/25 mm according to the ISO 4578 test method.

6. The laminate of claim 1, wherein the adhesive layer comprises by weight, from about 50% to about 70% polymer and from about 30% to about 50% flame retardant additive.

7. The laminate of claim 1, wherein the adhesive layer comprises no flame retardant additive.

8. The laminate of claim 1, wherein the laminate comprises from about 30 grams per square meter to about 150 grams per square meter adhesive layer disposed between the adhesive primer and the substrate layer of the surface layer.

9. The laminate of claim 1, wherein the at least one of the backing layers and the base layer comprises from about 100 grams per square meter to about 400 grams per square meter fiber reinforcement, and wherein the fiber reinforcement is a woven fabric.

10. The laminate structure of claim 1, wherein the laminate releases no HCL during combustion.

11. The laminate structure of claim 1, further including a decorative layer.

12. The laminate of claim 1, wherein the laminate is produced by a roll-forming process and has an areal density of about 2300 grams per square meter or less.

13. A laminate structure comprising: a backing layer comprising, by weight, from about 40% to about 50% polyester, and from about 50% to about 60% by weight fiber reinforcement; a base layer comprising a polyurethane alloy comprising polyurethane in combination with a terpolymer comprising polyamide, polyester and polyether or a combination thereof sub layer containing polyurethane in combination with a copolymer of at least two of polyamide, polyether, polyester, polyether, polyimide, polyphenylene oxide and polystyrene; a first adhesive layer disposed between the backing layer and the base layer, the adhesive layer comprising a thermoplastic polyurethane; a cap layer disposed on a surface of the base layer opposite the backing layer and comprising a polyurethane-based material; and a second adhesive layer disposed between the base layer and the cap layer, wherein the laminate structure having no amount of PVC in any component layer of the laminate, and exhibits abrasion resistance of less than 400 mg according to ISO 9352.

14. The laminate of claim 13 further comprising a primer layer disposed between the adhesive layer and the reinforcing backing layer.

15. The laminate of claim 14, wherein the second adhesive layer disposed between the base layer and the cap layer contains an organic or inorganic pigment.

16. The laminate of claim 15 further comprising one or more decorative or print layers disposed between the cap layer and the colored adhesive layer.

17. A laminate structure comprising: a backing layer comprising, by weight from about 20% to about 80% fiber reinforcement and from about 80% to about 20% thermoset or thermoplastic polymer; a base layer comprising polyurethane-based material; and an adhesive layer disposed on a first surface of the base layer between the backing layer and the base layer; and a cap layer comprising polyurethane, wherein the laminate meets the toxicity flaming and non-flaming test protocols pursuant to AITM 2.0007 with respect to HCN, CO, NO.sub.2, SO.sub.2/H.sub.2S, HF, and HCl limits, said limits being less than 150, 1000, 100, 100, 100, and 150 respectively as measured by specific optical density, in addition to Federal Aviation Regulation 25.853 MD with regard to the parameters of vertical burn, drip time and char of the laminate, said limits being less than 15 seconds, 5 seconds and 203 mm respectively.

18. A laminate structure comprising: a backing layer comprising, by weight, from about 40% to about 50% polyester, and from about 50% to about 60% by weight fiber reinforcement; a base layer comprising a sub layer containing polyurethane; a first adhesive layer disposed between the backing layer and the base layer, the adhesive layer comprising a thermoplastic polyurethane; and a cap layer disposed on a surface of the base layer opposite the backing layer and comprising a polyurethane-based material, wherein the laminate does not generate harmful halogen gases upon combustion, and produces NBS smoke levels of less than 200 according to the ASTN E662 flaming mode test method and by specific optical density (Ds) @ 4 min. non-flaming mode test method.

19. The laminate of claim 18 further comprising, a second adhesive layer disposed between the base layer and the cap layer.

20. The laminate of claim 19, wherein the second adhesive layer disposed between the base layer and the cap layer contains an organic or inorganic pigment, and further comprising one or more decorative or print layers disposed between the cap layer and the colored adhesive layer.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0012] The various embodiments of the present invention can be understood with reference to the following drawings. The components in the drawings are not necessarily to scale. Also, in the drawings, like reference numerals designate corresponding parts throughout the views.

[0013] FIG. 1 is a perspective illustration of a laminate structure, according to an embodiment of the present invention.

[0014] FIG. 2 is a perspective illustration of another optional laminate structure, according to an embodiment of the present invention.

[0015] FIG. 3 is a perspective illustration of another optional laminate structure, according to an embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

[0016] The laminate according to the invention is a multiple layer structure and contains predominantly urethane-based polymeric materials in the cap and base layers thereof, with no significant amount of PVC. As such, under combustion conditions, the laminate releases substantially no harmful halogen-based bases, such as HCl or other toxic gases, and exhibits toxicity and smoke generation parameters well below acceptable industry standards.

[0017] FIG. 1 is an exploded perspective illustration of a laminate structure 10 according to an embodiment of the present invention. According to FIG. 1, laminate structure 10 includes a backing layer 22 and a base layer 24 and a cap layer 26.

[0018] The backing layer 22 includes a fiber-reinforced thermoset polymer made from woven or non-woven fibers impregnated in a thermoset or thermoplastic polymer resin matrix. Suitable resins include, but are not limited to, saturated- or unsaturated- polysulfone, -polyphenolsulfone, -polyester, -phenolic resin, -epoxy resin, and mixtures thereof. The term unsaturated is used in reference to a thermoset polymer including a molecule having one or more carbon-carbon double bonds, and capable of further polymerization in a curing process, for example, by exposure to elevated temperatures. Once the unsaturated polymer has been cured and is present in the laminate structure, it is no longer referred to herein as an unsaturated polymer even though it may not be fully saturated in the cured state. For example, in various embodiments of the manufactured laminate structure in which polyester is present in the reinforcement layer, or the adhesive layer, or both, the polymer is referred to herein as polyester even though it may not be fully saturated in the cured state of the laminate structure.

[0019] The amount, by weight, of resin present in the backing layer 22, can range from about 20% to about 80%, in another embodiment from about 30% to about 70%, and in another embodiment from about 40% to about 50%. In one embodiment, the backing layer 22 contains, by weight, from about 20% to about 80% reinforcement fiber, and in another embodiment, from about 30% to about 70% by weight fiber, and in yet another embodiment from about 50% to about 60% by weight fiber. The fiber may be glass, aramids, carbon, polyvinyl alcohol (PVA), hemp, jute, organic materials, rayon, or other suitable fiber reinforcing material.

[0020] In one embodiment, the backing layer 22 is sufficiently stiff to provide good telegraph resistance, but sufficiently flexible to provide low weight and enable laminate structure 10 to be rolled on cores, for example 3-inch to 6-inch diameter cores, for ease of storage, transport and handling during application or installation. Telegraph resistance is an attribute of some structural laminates, for example, decorative NTF laminates, that keeps any unevenness in the underlying layer from being readily observed because of the stiffness of the NTF laminate. In addition, laminates available as continuous roll material offer economic advantages because less material is wasted when custom geometric pieces are cut from the roll.

[0021] The base layer 24 includes a layer of pretreated woven glass fabric or mat 24c. The glass component of glass layer 24c is pretreated by disposing glass fibers, sometimes in the form of a glass fabric or mat, in a polymer such as, for example, polyester, phenolic, epoxy, polysulfone, and mixtures thereof, or other similar polymers, to increase the smoothness of the surface, which enhances the capability of the surface to adhere to another surface, and to prevent the coatings applied thereto from impregnating the spaces between the fibers of the fabric.

[0022] Also included is an alloy layer 24a comprising polyurethane in combination with a homopolymer or a copolymer. The homopolymer or copolymer may be selected from a combination of known polymers, including but not limited to polyamide, polyester, polyether, polyimide, polyphenylene oxide, polystyrene and combinations thereof. In one embodiment, the copolymer comprises a terpolymer that may contain, for example, polyamide, polyester, and polyether, such that the base layer 24a as a whole includes from about 10% to about 100% polyurethane, and from about 10% to about 100% terpolymer, the terpolymer including from about 10% to about 100% of each of the polyamide, polyester, and polyether components.

[0023] Also included in base layer 24 is a primer layer 24b, disposed between the urethane/copolymer sub layer 24a and the glass sub layer 24c. Primer layer 24b generally comprises a PVC urethane composition, to enhance the adhesion of layers 24a and 24c, both of which include a urethane component. The primer layer could also be acrylic, urethane, epoxy, polyester or combinations thereof.

[0024] In one embodiment, the primer sub layer 24b is a thermoset adhesive containing a resin which can include, but is not limited to, polyester, polyurethane, epoxy, acrylic, and mixtures thereof. The amount of primer in sub layer 24b disposed between the base layer 24a and 24c is greater than about 0.25 oz. per square meter, in another example, the primer can range from about a 5 to about 40 oz. per square meter, in another example, from about 0.3 to about 25 oz. per square meter and in still another example, from about 0.5 to about 20 oz. per square meter. These amounts are based on a dry weight present in the laminate.

[0025] Finally, base layer 24 includes a very thin sealing sub layer 24d, comprising. PVC, which serves to prevent the glass fibers in sub layer 24c from etching the roller surface during the roll-forming process.

[0026] Known laminates include much higher percentages of PVC, which is not a significant component of the current laminate. In known laminates, the base layer comparable to sub layer 24a of this invention, generally is primarily comprised of PVC. PVC inherently releases high levels of halogen, particularly HCl, under conditions causing combustion. In addition, other components of known laminates may release NOx, HF, HBR, HCN, CO, CO.sub.2 and SO.sub.2 under these same conditions. Because the release of such halogens is harmful to those it comes in contact with and to the environment, efforts have been made to produce materials that have lower toxicity levels and yet exhibit the desirable wear characteristics of PVC. The laminate according to the invention eliminates PVC as a component of sub layer 24a, and instead comprises a polyurethane or a polyurethane alloy that renders a laminate product, when combined with a backing layer and a cap layer, that does not generate harmful halogen gases, particularly I ICI, upon combustion. An additional benefit of the laminate of the invention is the generation of lower levels of smoke having these harmful components entrained therein.

[0027] The laminate of the invention may include one or more fiber-containing layers. Fiber materials which can be used in the backing layer 22, and as part of the base sub layer 24c, for example, can include, for example, glass, aramids, carbon, polyvinyl alcohol (PVA), hemp, jute, organic materials, and rayon. Depending upon the material of the fiber/woven fabric and its specific gravity, the aereal density of the laminate can vary from about 100 grams per square meter to about 400 grams per square meter and all ranges there between. For example, in various embodiments in which glass is used as the reinforced fiber, the aereal density of glass in at least one of the backing layer 22 and the base sub layer 24c ranges from about 200 to about 400 grams per square meter, in another embodiment from about 250 to about 350 grams per square meter, and in another embodiment from about 275 to about 325 grams per square meter. In another embodiment in which aramid fiber is used, the areal density of the fiber/woven fabric of at least one of the backing layer 22 and the base sub layer 24c ranges from about 100 to about 300 grams per square meter, for example.

[0028] The laminate may further include adhesive layer 23, which is shown disposed between the backing layer 22 and the base layer 24. Adhesive layer 23 contains a thermoplastic resin which can include, but is not limited to, polyurethane, for example a polyester-based polyurethane, acrylic polyamide, epoxy polyvinyl alcohol, polyester, and mixtures thereof, as well as additional thermoplastic polymers having similar melting temperatures and adhesive properties. In another embodiment, adhesive layer 23 includes two or more thermoplastic polymers. For example, a suitable adhesive layer 23 may include, by weight, from about 70% to about 90% of a polymer as listed above, for example a polyester-based polyurethane, and also includes from about 10% to about 30% by weight of a second thermoplastic polymer selected from the group of polyamide, polyvinyl alcohol, polyester, phenoxy and mixtures thereof.

[0029] The amount of adhesive layer 23 present in laminate structure 10, and disposed between backing layer 22 and base layer 24, can range from about 30 to about 150 grams per square meter, in another example from about 70 to about 100 grams per square meter, and in still another example from about 70 to about 90 grams per square meter. The adhesive 23 may be, but does not have to be, a heat-activated adhesive which melts during lamination at elevated temperature as will be further described.

[0030] Adhesive layer 23 optionally contains a flame retardant additive in quantities based on parts per hundred resin. As is shown in FIG. 2, additional adhesive layers 23a and or 23b may be included in the laminate structure. Generally, a flame retardant additive is included in at least adhesive layers 23 and 23a, though it may also be included in layer 23b. Suitable flame retardants include, but are not limited to, aluminum trihydrate, magnesium hydroxide, organophosphates, red phosphorous, phosphorus compounds, zinc borate, boric acid, oxides of boron, melamine(s), melamine derivatives such as salts thereof with organic or inorganic acids, ammonium polyphosphate, ammonium pentaborate, mixtures of zinc salts of alkali metals containing nano-clay and/or functionalized nano-metals, and mixtures thereof. The amount of flame retardant, alone or as a mixture of two or more flame retardant additives, can be present in up to about 40 parts per hundred resin, in another embodiment up to about 20 parts per hundred resin, in another embodiment up to about 15 parts per hundred resin, and in yet another embodiment up to about 10 parts per hundred resin, and all ranges there between. Also, it should be understood that a flame retardant additive is optional and therefore, in another embodiment, the adhesive 23 contains no flame retardant additive. That is, when the adhesive contains no flame retardant additive, any flame retardant performance if present in the adhesive layer would be characteristic of the inherent properties of the at least one thermoplastic polymer used in the adhesive layer 23.

[0031] FIG. 2 is an exploded view illustration of laminate structure 20 which includes all of the layers of laminate structure 10, and further includes optional print or decorative layer 25 and additional adhesive layers 23a and 23b and additional primer layer 27. A primer can be used to promote the adhesion of the adhesive layer. In both laminate structures 10 and 20 the composition of the adhesive and primer layers is generally different. For example, while both may be urethane-based material layers, each may contain additives particularly suited for certain purposes.

[0032] With further reference to FIG. 2, in another embodiment, laminate structure 20 includes a decorative layer 25. In one embodiment the decorative layer 25 is a layer disposed beneath cap layer 26 such that it is visible through the cap layer. Decorative layer 25 includes, but is not limited to, a polymer selected from acrylic, polyurethane, PVC and mixtures thereof. Decorative layer 25 may include a colorant or pigment or a so-called effect pigment such as aluminum or Nacre. Optionally, decorative layer 25 may be (i) opaque, or decorative layer 25 may be (ii) clear translucent, or decorative layer 25 may be (iii) colored translucent, or decorative layer 25 may be any combination of the foregoing. The laminate may, in some embodiments, include additional decorative layers including, but not limited to, at least one or more of, a print layer, a metal layer, a varnish, and/or a polymer. For example, a further decorative layer (not shown) can be at least one of a printed pattern, an embossed pattern which provides texture, and a color or pigment layer. The decorative layer 25 may further include at least one flame retardant additive, selected from but not limited to aluminum trihydrate, magnesium hydroxide, organophosphates, red phosphorous, phosphorus compounds, zinc borate, boric acid, oxides of boron, melamine(s), melamine derivatives such as salts thereof with organic or inorganic acids, ammonium polyphosphate, ammonium pentaborate, mixtures of zinc salts of alkali metals containing nano-clay and/or functionalized nano-metals, and mixtures thereof. The amount of flame retardant, alone or as a mixture of two or more flame retardant additives, can be present in up to about 40 parts per hundred resin, in another embodiment up to about 20 parts per hundred resin, in another embodiment up to 15 parts per hundred resin, and in yet another embodiment up to about 10 parts per hundred resin, and all ranges there between.

[0033] In other embodiments, the laminate structure 10 shown in FIG. 1 or 2 may obtain a textured, colored, or patterned appearance without the addition of decorative layer 25. In these embodiments, cap layer 26 may include a pigment. Alternatively, an adhesive layer 23b, having pigment disposed therein, may be disposed between base layer 24 and cap layer 26. In yet another alternative embodiment, pigment is disposed in both cap layer 26 and adhesive layer 23b. Additionally, pigment may be disposed in base layer 24 rather than or in addition to layers 23b and/or 26. In yet another embodiment, a texture or patterned appearance is imparted to the laminate 10 or 20 by embossing one or more surfaces of any of the foregoing layers 23b, 24, or 26, or any optional layer provided there between.

[0034] With reference to FIGS. 2 and 3, FIG. 3 is an exploded view structure of the laminate structure 30 which includes all the layers and constituents of structure 20 with the exception of the print or decorative layer 25 and is another embodiment of the invention.

[0035] The cap layer 26 and base layer 24 are sometimes considered together as the surface layer of the laminate. This surface layer adheres well to the backing layer 22 such that the peel resistance between the surface layer and the backing layer 22, when tested according to the ISO 8510 standard test method used in the industry, performs extremely well. After aging for 500 hours at 70 C., the samples tested exhibited: peel resistance values of at least about 103 Newtons (N) per 25 millimeters (mm), and in another example, at least about 105 N/25 mm; and bondability, according to test method ISO 4578, ranging from about 31 to about 33.9 N/25 mm.

[0036] As set forth in Table 1, the laminate as described herein was tested in accord with ABD-0031 Standards. Three samples in accord with the invention were tested to generate the data presented in the Table. Each sample included the same or comparable backing and adhesive layers, i.e. samples 1 and 2 used phenolic backing material available commercially from McGill, and sample 3 included a phenolic backing material prepared by the applicant. With regard to the base layers of the tested laminates, all three samples used the same seal, glass, and primer sub layers, and included a urethane-terpolymer sub layer as the main base layer, (24a in FIGS. 1 and 2). The use of the urethane-terpolymer composition, as opposed to the PVC composition of known laminates, renders significantly less HCl under combustion conditions. In addition, PVC-based laminates degrade quickly at high temperatures. Other known laminates contain silicone compositions, which have significantly inferior slip resistance, and are a thermoset and therefore cannot be recycled. Finally, all three samples tested included a polyurethane cap layer. The results in Table 1 verify that with regard to the production of smoke, under both flaming and non-flaming test conditions, the laminate of the invention recorded data well below acceptable industry standard levels. Further, when tested according to AITM 2007, the laminate according to the invention released no HCl, and levels of other potentially toxic components well below acceptable levels. Table 1 provides full test data for all areas of performance critical to qualification of the laminate for use in the airbus transportation industry.

[0037] The laminate structures of the present invention are relatively light weight, having a maximum aereal density up to about 2300 grams per square meter, in another embodiment about 1800 to about 2100 grams per square meter or less, in another example, less than about 1800 grams per square meter, and in yet another example, an aereal density of about 1500 grams per square meter.

TABLE-US-00001 TABLE 1 ABD-0031 Specification Property Poly.2415 Poly.2415 Texture 92R 92R Color Poly.2415 Lubrizol Blue Blue CM Construction Cap Cap Cap + Adh Cap + Adh Backing Test McGill McGill 6100 6100 Sample Methods Spec RKH001 RKH002 RKG 621 RKG 622 Thickness ISO 2286-3 69.8 mil 64.7 mil 57.7 62.4 Weight ISO 2286-2 <2300 2087 1915 1933 1973 grams UV (DE) ASTM G- Test No change No 0.527/1.1 .951/1.078 53 (UVA 50.100 change 340.sub. Static Dry MD ISO 8295 >.25 0.973 1.022 0.816 0.687 Coefficient of Wet MD 0.83 0.878 0.706 0.59 Friction Dry XD 1.066 0.999 0.919 0.631 Wet XD 0.845 0.755 0.704 0.637 Dynamic Dry MD >.25 0.678 0.875 0.73 0.594 Coefficient of Wet MD 0.76 0.779 0.617 0.545 Friction Dry XD 0.709 0.781 0.845 0.58 Wet XD 0.716 0.605 0.642 0.523 Dimensional md/cmd <.2% 0.13% 0.10% 0.00% 0/0 Stability Curling EN434 (70 C. <10 mm fail fail fail 9.75 1 week) Abrasion (Loss ISO 9352 <1000 mg. 0.5558 0.6525 0.2042 0.2289 of mass) 50% Impact Spec. Para >9 J 100% pass 40% 15.4 14.4 failure energy 2.2 Tear MD ISO 4674-1 >60 N 166.7 78.3 186 131 XD Method A 190.3 122.3 181 182 Peel MD ISO 8510-2 >50 N >50 >50 CSF CSF Resistance or CSF (Top layer & XD xxx xxx CSF CSF reinforcement) Peel MD 84.9 57.0 17.4 89.7 Resistance XD xxx xxx 34.6 56.4 (Top material and phenolic) Bondability ISO 4578 >20 N 31.47 33.9 29.8 32 Sealability ISO 11339 No Air Coh. Coh. 66.4 flow (pass) (pass) Formation of Spec Para No pass pass no change pass bubbles 2.2 bubbles Stain resistance- (Citric acid ISO 4586-2 5 rating 5 5 5 5 10%) (Red wine) Clause 15 5 5 5 5 (20% urea) Procedure A 5 5 5 5 Vertical Burn Far 25.853 <15 sec. 0.8 5.11 0 5.3 12 sec. (After MD flame) sec. (Drip time) <5 sec. 0 0 0 0 sec. (Burn length) 203 mm. 1.53 1.87 2 1.6 in. XD <15 sec. 5.2 4.7 1.76 6.48 <5 sec. 0 0 0 0 203 mm. 1.0 1.53 1.46 1.46 Heavy metals None None None XXX and antimony oxide Seaming EN 684 250 N/50 mm. 338 N 409 N 361 481 NBS Smoke ASTN E662 <200 171.1 106.22 121.2 101.2 (Flaming mode) (Non flaming DS @ 4 min. <200 120.7 131.2 146 113 mode) Toxicity HCN 150 2.0 2 10, 10 10 Flaming CO 1000 150.0 100 130 250 (AITM 2.007) NO/NO.sub.2 100 80, 50 70, 90 60, 80 40 NOx retest 100 83.3 86.7 xxx Property SO.sub.2/H.sub.2S 100 1.0 0 0 0 HF 100 0.0 0 0 0 HCI 150 0.0 0 0 0 Toxicity Non- HCN 150 0.0 0 1 2 Flaming CO 1000 0.0 0 0 50 NO/NO.sub.2 100 0.0 0 0 20 SO.sub.2/H.sub.2S 100 0.0 1 0 0 HF 100 0.0 0 0 0 HCI 150 0.0 0 0 0 Blooming No pass pass pass XXX pass blooming @ 3 weeks Peel ISO 8510-2 >40 N 103.1 105.4 CSF Resistance or CSF after 500 hrs. (@70 C. Tear strength ISO 4674-1 >50 N 146.72 64.38 131 after 500 hrs. @70 C. (MD) (XD) Method A 158.78 86.92 113

[0038] Laminate structures herein have an abrasion resistance shown by Taber abrasion testing, ISO 9352, with mass loss of less than about 653 milligrams, and in another embodiment, less than about 556 milligrams.

[0039] When tested according to FAA specifications, as set forth in Table 1, the laminate of the invention demonstrated a dynamic coefficient of friction between about 0.52 and 0.78 for wet and between about 0.58 and 0.87 for dry sled with either rubber or leather as described in FAR 25.793 Amendment 25-51 procedure A, all well above the required 0.25.

[0040] The laminates were also tested according to FAR 25.853 MD with regard to vertical burn. As shown in the table, the laminate is subjected to an open flame. The test records the time it takes for the sample to extinguish (must be less than 15 seconds), the drip time (must be less than 5 seconds), and the length of the char (must be less than 203 mm or 8.02 inches). As is seen in Table 1, the samples according to the invention recorded burn times of 0.8 sec., 5.11 sec., 5.3, 0 sec, all well below the 15 sec. limit. Drip time for all three samples was 0, and char lengths were 1.53 in., 1.6 in. 1.87 in and 2.0 in., again all well below the 8.02 in. threshold.

[0041] The tear strength of laminate structures herein is well above the required 50 Newtons, in one embodiment being greater than about 146 Newtons, and in another embodiment, greater than about 158 Newtons according to ISO 4674, method A.

[0042] In another embodiment, laminate structures herein arc stain resistant as per ISO 4586-2, clause 15, method A, Procedure A, rating 5. An additional layer of adhesive, shown in FIG. 2 as adhesive layer 23b, may be added to the laminate as discussed hereinabove. The addition of this adhesive layer, disposed between the base layer 24 and the cap layer 26, provides unexpected abrasion resistance to the laminate structure. Table 1 shows, for example with respect to Sample 1, abrasion of 555.8 mg., according to standard test ISO 9352, which is well below the acceptable 1000 mg threshold. This test records milligrams of laminate abraided per 1000 revolutions of a wheel against the surface. With the addition of adhesive layer 23b, the laminate loses only 200 mg if un-pigmented and 400 mg if pigmented. Both results represent significant abrasion resistance improvement.

[0043] The laminate structure according to the invention may be made by a conventional roll-forming process, or other known laminating techniques. The resulting laminate may exhibit various dimensions, for example a fixed width along its length, such as about 1.5 meters wide, and variable length, for example, greater than about 6.5 meters long, in another example, from about 10 meters to about 25 meters long, and in another example, at least about 30 meters long.

[0044] Roll-forming processing parameters may vary depending on the chemistry of adhesive and primer and the thickness of the laminate. For example, processing temperatures may vary. The lamination step may be carried out at a relatively low surface temperature that ranges from about 170 F. to about 300 F., in another embodiment from about 170 to about 250 F., and in another embodiment from about 170 to about 220 F. Additionally, the pressure may vary from about 20 psi to about 40 psi. The roller speed can also vary and can range from about 2 meters/minute to about 5 meters/minute, and in other exemplary embodiments, from about 2.5 meters/minute to about 4 meters/minute.

[0045] It is to be understood that for purposes of the present specification and claims the range and ratio limits recited herein can be combined. For example, if ranges of 10 to 100 and 20 to 90 arc recited for a particular parameter, it is understood that the ranges of 10 to 90 and 20 to 100 are also contemplated. Independently, if minimum values for a particular parameter are recited, for example, to be 1, 2, and 3, and if maximum values for that parameter arc recited to be, for example, 8 and 9, then the following ranges are all contemplated: 1 to 8, 1 to 9, 2 to 8, 2 to 9, 3 to 8, and 3 to 9.

[0046] The following examples of dimensionally stable laminates made. according to embodiments of the present invention are further disclosed, and do not otherwise limit the scope of the invention.

[0047] Laminates in keeping with the invention were prepare and performance tested, the data from those tests being presented in Table 1. An exemplary laminate composition, in accord with tested sample 1, is shown in Table 2.

TABLE-US-00002 TABLE 2 LAMINATE - SAMPLE 1 LAYER* Weight (g/m.sup.2) % Composition Urethane cap (26) 243 12.47 Urethane/terpolymer 981 50.30 Base Layer (24a) Primer Layer (24b) 16.6 0.85 Glass Layer (24c) 218 11.19 Adhesive (23a) 33.20 1.7 Adhesive (23) 33.20 1.7 Phenolic Backing (22) 425 21.79 Total 1950 100 *numbers refer to FIGS. 1 & 2

[0048] The present invention is intended to include such modifications and alterations in so far as they fall within the scope of the appended claims or the equivalents thereof