Patent Description:
While "Soft- Touch" / "Soft-Feel" leather like materials are well known in the art, the traditional products have undesirable burn properties when used in commercial transportation for upholstering or covering surfaces; i.e. they readily burn and/or give off toxic fumes/smoke. Current "soft-touch" products for general use (automotive, consumer products) readily burn or melt and produce toxic smoke. In commercial aviation there are even fewer options; due to the stringent regulatory requirements designed to protect passenger safety in the event of a fire. Synthetic leathers make up the majority of what is used. These often have marginal burn properties which limits where and how they can be used. Additionally many have poor durability and stain easily.

The art has tried to address this by using fire resistant silicones. Silicone products have been developed that can be used for a soft feel and some of them can meet aviation requirements. However these silicones feel "sticky" or "tacky" and while soft, are generally not mistaken for leather. Additionally, because of the stickiness, silicones can pick up and retain dirt and stains.

Further, other soft feel products do not have great damage resistance/ durability rendering them unsuitable for high wear areas such as aircraft or other interiors or had a soft feel but lacked the compressive quality or could not pass the burn requirements. <CIT> provides a fire extinguishing adhesive film which when used with a decorative polyvinyl fluoride wall coating will exceed the FAA standards.

According to a first aspect there is provided a laminate material for use in covering surfaces in an aircraft characterized in that the laminate material comprises:.

The laminate material may further include a layer of an impregnated glass fabric of weight in the range <NUM>-<NUM>/m2 between the PVC middle layer and the poly(vinyl fluoride) or poly(vinylidene fluoride) layer.

The laminate material may further include a layer of primer to bind the layer of impregnated glass fabric to the poly(vinyl fluoride) or poly(vinylidene fluoride) layer. The primer may have a thickness in the range <NUM> to <NUM>.

The laminate material may further include a layer of primer to bind the top layer to the middle layer. The primer may have a thickness in the range <NUM> to <NUM>.

The laminate material may be provided such that the primer comprises acrylic, polyester, polyurethane, epoxy or phenolic resins.

The laminate material may further include a layer of an adhesive on the bottom of the poly(vinyl fluoride) or poly(vinylidene fluoride) layer. The layer of adhesive may weigh in the range <NUM>-<NUM>/m2.

The laminate material may further include a layer of silicone foam with glass fabric backing on the layer of adhesive. The silicone foam layer may be between <NUM> and <NUM> thick.

The laminate material may be disposed such that the flame retardant may be selected from the group consisting of hydrated aluminas, magnesium hydroxide, phosphate ester plasticizers, tetrabromophthalates, tetrachlorophthalates, chlorinated hydrocarbons, ammonium octamolybdate, alkyl aluminum phosphonates and phosphinates, zinc sulfides, zinc borates, zinc hydroxy stannates, and bismuth oxide.

The present invention is an engineered high performance decorative laminate that has a soft feel, for example like leather or synthetic leather. It will meet or exceed all Federal Aviation Administration ("FAA") regulations. Specifications for fire, smoke and toxic gases for use in all areas of commercial aircraft are considered. It will also have excellent stain resistance and durability. By coating a poly(vinyl halide) or a poly(vinylidene halide) film with a flame retarded multiblock copolymer and optimizing this layer for feel and burn these limitations were overcome.

"Multiblock copolymers" as used herein include polyurethanes (PU), copolyamides (COPA), copolyesters (COPE), and styrenics such as SIS, SBS, SIBS. These copolymers are cross-linkable thermoplastics or thermosets.

"Poly(vinyl chloride)" or "PVC," as used herein, includes homopolymers of vinyl chloride, as well as polymerization products of vinyl chloride and one or more co-monomers. For example, the PVC resin can be a copolymer of vinyl chloride and ethylene, or a copolymer of vinyl chloride and propylene. The PVC resin can also be the polymerization product of vinyl chloride and an ester monomer having formula H<NUM>C=C(RI)OC(=O)R<NUM> or H2C(R<NUM>)C(=O)OR<NUM>, where R' and R<NUM> are, independently, C1-<NUM> alkyl. An example of such a resin is a copolymer of a vinyl chloride monomer and a methyl methacrylate monomer. Another example of such a resin is a copolymer of a vinyl chloride monomer and a vinyl acetate monomer. Combinations of these PVC resins may also be used.

"Poly(vinylidene fluoride)" or "PVDF," as used herein, includes homopolymers of vinylidene floride, as well as polymerization products of vinylidene fluoride and one or more co-monomers. For example, the PVDF resin can be a copolymer of vinylidene fluoride and hexafluoropropylene, or a copolymer of vinylidene fluoride and chlorotrifluoroethylene. The PVDF resin can also be the polymerization product of vinylidene fluoride and an ester monomer having formula H<NUM>C=C(R<NUM>)OC(=O)R<NUM> or H<NUM>C(RI)C(=O)OR<NUM>, where Ri and R<NUM> are, independently, C1-<NUM> alkyl. An example of such a resin is a copolymer of a vinylidene fluoride monomer and a methyl methacrylate monomer. Another example of such a resin is a copolymer of a vinylidene fluoride monomer and a vinyl acetate monomer. Combinations of these PVDF resins may also be used. Blends of PVDF with other polymers can also be used, for example PVDF/acrylic blends.

"Prepreg" are coatings in which polymers such as PET, PPS, and PEEK are suspended in an organic liquid, optionally with flame retardants.

"Silicone foam" is a silicone material containing open and/or closed cells and are available from a variety of manufacturers. Foams are available in a wide variety of durometers and with glass backing for durability. Specifically selected and designed systems with improved flame retardant properties beyond the natural flame retardant properties of silicone based materials is required to meet the intent of the invention.

"Organosols" are coatings in which PVC is suspended in an organic liquid optionally with flame retardants.

Suitable adhesives and primers include, but are not limited to: phenolic resins, polyesters, epoxies, polyurethanes, and methacrylics. Because the adhesives need to be compatible with the materials they are bonding and provide the requisite strength for the application, typically the manufacturer of the laminate layer will specify which adhesives or primers are compatible in use with their products.

The compositions contain one or more flame retardant or combinations of flame retardants. The flame retardants can be liquid or solid. Preferred flame retardants include but are not limited to aluminum trihydroxide, available from various suppliers, including Alcoa, under the product name Hydrated Aluminas; magnesium hydroxide, available from various suppliers, including Albermarle, under the trade name MAGNIFIN (e.g., Magnifin H-<NUM> or Magnifin H-<NUM>); flame-retardant plasticizer such as phosphate ester plasticizers, available from various suppliers, including Ferro, under the trade name SANTICIZER (e.g., Santicizer <NUM>), tetrabromophthalates, polymeric plasticizers (for example, Admix <NUM>, available from Teknor Apex), combinations of bromo and chlorophthalates (for example, Unitex <NUM>-<NUM>), and chlorinated hydrocarbons (for example, Cercelor S52); and ammonium octamolybdate, available from various suppliers, including Polymer Additives Group, under the trade name Climax AOM; Alkyl aluminum phosphonates and phosphinates such as AMMP and DEPAL sold by ICL-IP and Clariant, respectively, zinc sulfides, sold by Sachtleben, zinc borates sold by US Borax Inc, and zinc hydroxy stannates sold as ZS <NUM> by 3N International; bismuth oxide, sold by 3N International. Additional flame retardants are described in Linsky et al. , <CIT>, and Shtekler et al. The compositions preferably include at least about <NUM> parts total flame retardant per <NUM> parts polyvinyl chloride resin, and more preferably from about <NUM> parts to about <NUM> parts total flame retardant per <NUM> parts polyvinyl chloride resin. The composition may include, for example, from about <NUM> parts to about <NUM> parts, from about <NUM> parts to about <NUM> parts, or from about <NUM> parts to about <NUM> parts flame retardant plasticizer per <NUM> parts polyvinyl chloride resin.

In one embodiment of the present invention, as schematically illustrated in <FIG>, the laminate comprises a top layer of clear flame retarded multiblock copolymer film bonded to a clear poly(vinyl halide) or a poly(vinylidene halide) film, optionally containing fire retardants. This laminate is then bonded to a flame retarded PVC layer containing pigments and flame retardants. It may be necessary to use a primer in order to attain good adhesion between the laminate and the PVC layer. These layers are bonded with a suitable glass fabric that has been impregnated with a fused organosol material. Optionally there may be a fluoropolymer layer bonded to the other side of the impregnated glass in which case an optional primer layer would be required. Commercially available examples of suitable materials for this embodiment are set forth below:.

The soft touch film is a grade of Aerofine available from Akzo Nobel, preferably the <NUM> that is <NUM>-<NUM> mils thick and is composed of a polyurethane over a PVC base. The glass fiber is sold as <NUM> Greige glass from BGF. The middle PVC layer was S1670 sold by Spectrum. The prepreg was S1687 sold by Spectrum. The acrylic primer is <NUM> a flexible product adhesive sold by Dupont.

In another embodiment of the present invention the laminate comprises a top layer of clear urethane/polycarbonate film bonded to a clear PVDF/acrylic film containing fire retardants which is then bonded to a PVC layer containing pigments and flame retardants. These layers are bonded with a suitable adhesive to a fire resistant silicone foam/glass fabric. Optionally there may be a fluoropolymer layer between the PVC layer and the silicone foam.

Referring to <FIG>, in this embodiment the laminate comprises a top ply of a clear layer that is about from <NUM> ma to about <NUM> mil of a flame retarded multiblock copolymer on a poly(vinyl halide) or a poly(vinylidene halide) layer. Suitable films are, for example sold as Aerofine <NUM> by Akzo Nobel. Optionally bound to the top ply using a suitable primer up to <NUM> mil in thickness. The prior materials are then bonded to a PVC layer that is <NUM> to <NUM> mil in thickness which can be foamed or unfoamed. An organosol impregnated glass fabric is optionally bound to the PVC layer, wherein the glass fabric weighs from about <NUM> to about <NUM> oz/yd<NUM>, and the organosol is fused. A fluoropolymer layer ( PVF or PVDF) such as Tedlar® offered by Dupont or Fluorex® products offered by Akzo Nobel is optionally indirectly bonded to PVC, indirectly as a primer layer is required to be used in conjunction with the optional fluoropolymer layer. The fluoropolymer layer is preferably from about <NUM>-<NUM> mils thick. An adhesive layer is then bonded as the final layer; the adhesive layer is preferably <NUM> to <NUM> oz/yd<NUM>.

Referring to <FIG>, in this embodiment the laminate comprises a top ply of clear multiblock copolymer with poly(vinyl halide) or poly(vinylidene halide). Suitable films are manufactured by Akzo Nobel. Bound to the top ply using a suitable adhesive, such as Dupont <NUM> adhesive primer, is a <NUM>-<NUM> mil clear PVDF/acrylic film containing fire retardants such as Airfilm LHR (Low Heat Release) offered by Schneller. The prior materials are then bonded to a fluoropolymer layer ( PVF or PVDF) such as Tedlar® offered by Dupont of Soliant products offered by Akzo Nobel. The fluoropolymer layer is preferably from about <NUM>-<NUM> mils thick. A silicone foam with glass backing is bound to the fluoropolymer layer using a suitable adhesive such as HA <NUM> from Schneller. In one embodiment the silicone foam is <NUM> mils thick. Suitable silicone foams can be purchased from Rogers Corporation under the brand Bisco®.

Referring to <FIG>, in this embodiment the laminate comprises a fluoropolymer backing such as PVDF or PVF onto which a PVC material from <NUM>-<NUM> mils in thickness is applied. The PVC can be calendared, extruded or coated; it may contain pigments for coloration and fire retardants. In some instances it may be comprised of a couple of different layers of PVC and some or all of it may be foamed. A top ply of <NUM>-<NUM> mils polyurethane/silicone is applied to the PVC.

Table <NUM> below sets forth the desired characteristics for the laminates of the present invention including relevant regulations where applicable.

Laminates of the present invention can be applied by any suitable means. In certain instances they may be vacuum formed into place using means known in the art or applied using rollers or other means of exterior pressure.

Claim 1:
A laminate material for use in covering surfaces in an aircraft characterized in that the laminate material comprises:
a) a top layer formed by coating a poly(vinyl halide) or a poly(vinylidene halide) film with a flame retarded multiblock copolymer of a cross-linkable thermoplastic or thermoset copolyamide, copolyester, styrenic or polyurethane;
b) at least one PVC middle layer, foamed or unfoamed, adjacent the poly(vinyl halide) or poly(vinylidene halide) film layer;
c) a poly(vinyl fluoride) or poly(vinylidene fluoride) layer adjacent that at least one PVC middle layer; and
wherein the laminate meets or exceeds FAA regulations;
wherein the PVC middle layer includes at least one flame retardant;
wherein the poly(vinyl fluoride) or a poly(vinylidene fluoride) layer is between <NUM> and <NUM> (<NUM> and <NUM> mils) thick;
wherein at least one PVC layer is between <NUM> and <NUM> (<NUM> and <NUM> mils thick; and wherein the top layer has a thickness in the range <NUM> and <NUM> (<NUM> and <NUM> mils).