초록 ▼

A rubber or elastomer laminate comprising a plurality of layers that can be vulcanized or crosslinked, wherein at least one of the layers includes a blowing agent. During vulcanization the layer containing the blowing agent expands to form a closed cell foam rubber layer. In a preferred embodiment,

A rubber or elastomer laminate comprising a plurality of layers that can be vulcanized or crosslinked, wherein at least one of the layers includes a blowing agent. During vulcanization the layer containing the blowing agent expands to form a closed cell foam rubber layer. In a preferred embodiment, the closed cell foam rubber is interposed between two layers free or substantially free of a blowing agent. Composites, including the laminate, and preferably a metal article, most preferably a rail for use in an electric transit system, are formed by bonding the laminate to the metal article using a suitable bonding agent such as a rubber to metal adhesive. In a preferred embodiment, the unvulcanized laminate is applied or connected to the metal article prior to vulcanization. Rubber clad rail assemblies having a closed cell rubber foam layer and methods for preparing the same are disclosed.

대표청구항 ▼

What is claimed is: 1. A composite rail for trains or other vehicles, comprising: a metal rail; and a laminate vulcanized to a portion of the metal rail utilizing a rubber to metal adhesive, wherein the laminate comprises two or more rubber-containing layers, wherein a first layer (i) is a closed c

What is claimed is: 1. A composite rail for trains or other vehicles, comprising: a metal rail; and a laminate vulcanized to a portion of the metal rail utilizing a rubber to metal adhesive, wherein the laminate comprises two or more rubber-containing layers, wherein a first layer (i) is a closed cell foam rubber layer, and wherein a second layer (ii) of the laminate has less closed cell foam rubber than said first layer (i) or is free of closed cell foam rubber and is disposed on an outer surface of the laminate, wherein the laminate includes a third rubber layer (iii) having less closed cell foam rubber than said first layer (i) or is free of a closed cell foam rubber that is interposed between the rail and said first closed cell foam rubber layer (i), wherein the laminate is dielectric, and wherein the rail includes a bottom flange, a top flange adapted to support a train or other vehicle, and a web portion interconnecting the bottom flange and top flange. 2. The composite rail according to claim 1, wherein the first closed cell foam rubber layer (i) has a thickness of about 1 mm to about 30 mm, and wherein each of the second (ii) and the third (iii) rubber layers, independently, has a thickness of about 1 mm to about 20 mm. 3. The composite rail according to claim 2, wherein the first closed cell foam rubber layer (i) is derived from a composite comprising from about 1 to about 20 parts by weight of a blowing agent based on 100 total parts by weight of rubber in the first closed cell foam rubber layer (i). 4. The composite rail according to claim 3, wherein the blowing agent is sodium bicarbonate, p-toluene sulfonyl semicarbazide, p-p'-oxbis (benzenesulfonyl hydrazide), azodicarbonamide, or combinations therefore, and wherein the blowing agent is present in an amount from about 1 to about 10 parts by weight per 100 total parts by weight of rubber in the first closed cell foam rubber layer (i). 5. The composite rail according to claim 3, wherein the rubber utilized in each layer of the laminate independently is natural rubber, neoprene, or EPDM, or a combination thereof. 6. The composite rail according to claim 3, wherein the laminate is connected to at least the bottom flange and the web portion of the rail to an underside of the top flange of the rail on each side of the rail. 7. A street or rail bed having a composite rail according to claim 6 connected therein. 8. The composite rail according to claim 1, wherein the first closed cell foam rubber layer (i) has a thickness of about 3 mm to about 10 mm, and wherein each of the second (ii) and the third (iii) rubber layer, independently, has a thickness of about 2 mm to about 4 mm. 9. A street or rail bed having a composite rail according to claim 1 connected therein. 10. The composite according to claim 1, wherein a second vulcanized laminate comprising one or more rubber layers is connected to a portion of the vulcanized laminate. 11. A composite including a closed cell foam rubber layer, comprising: a substrate having a dielectric laminate cured thereon, wherein the laminate includes a closed cell foam rubber layer interposed between a first rubber layer and a second rubber layer, said first and second rubber layers comprising less closed cell foam rubber than the closed cell foam rubber layer or free of closed cell foam rubber, said closed cell foam rubber layer derived from a composition including a blowing agent. 12. The composite according to claim 11, wherein the closed cell foam rubber layer has a thickness of from about 1 mm to about 30 mm, and wherein the first and second rubber layers independently have a thickness of about 1 mm to about 20 mm. 13. The composite according to claim 12, wherein the substrate is metal, ceramic, plastic, rubber, elastomer, cement, concrete, or a combination thereof. 14. The composite according to claim 13, wherein the closed cell foam rubber layer is derived from a composition comprising from about 1 to about 20 parts by weight of a blowing agent based on 100 total parts by weight of rubber in the closed cell foam rubber layer. 15. The composite according to claim 14, wherein the rubber utilized in each layer of the laminate independently includes natural rubber, neoprene, or EPDM, or a combination thereof. 16. The composite according to claim 14, wherein the substrate is a rail, wherein the rail includes a bottom flange, a top flange adapted to support a train or other vehicle, and a web portion interconnecting the bottom flange and top flange, wherein the laminate is connected to at least the bottom flange and the web portion of the rail to an underside of the top flange of the rail on each side of the rail, and wherein the laminate is cured on the rail in the presence of a rubber-to-metal adhesive interposed between the laminate and the rail. 17. The composite according to claim 16, wherein the closed cell foam rubber layer has a thickness of about 3 mm to about 10 mm, and wherein each rubber layer free of a closed cell foam, independently, has a thickness of about 2 mm to about 4 mm. 18. A street or rail bed having a composite rail according to claim 17 connected therein. 19. The composite according to claim 11, wherein a second cured laminate comprising one or more rubber layers is connected to a portion of the cured laminate. 20. A method for preparing a composite rail, comprising the steps of: applying an uncured laminate to a portion of a rail; and curing the laminate to form a composite rail, wherein the laminate comprises two or more layers, wherein a first rubber layer is a closed cell foam rubber layer derived from a rubber composition comprising a blowing agent, and wherein a second rubber layer of the laminate is disposed on an outer surface of the laminate, wherein the second rubber layer comprises less closed cell foam rubber than the first rubber layer or is free of closed cell foam rubber. 21. The method according to claim 20, wherein the laminate is cured without the use of a mold. 22. The method according to claim 21, wherein the laminate includes a third rubber layer interposed between the rail and first layer, wherein the third rubber layer comprises less closed cell foam rubber than the first rubber layer or is free of closed cell foam rubber, and wherein the laminate is dielectric. 23. The method according to claim 22, wherein the rail includes a bottom flange, a top flange adapted to support a train or other vehicle, and a web portion interconnecting the bottom flange and top flange, wherein the first rubber layer has a thickness of about 1 mm to about 30 mm, and wherein the second and third rubber layers, independently, have a thickness of about 1 mm to about 20 mm. 24. The method according to claim 23, wherein the first rubber layer is derived from a composition comprising from about 1 to about 20 parts by weight of a blowing agent based on 100 total parts by weight of rubber in the first rubber layer. 25. The method according to claim 24, wherein the rubber utilized in each layer of the laminate independently is natural rubber, neoprene, or EPDM, or a combination thereof, and wherein the laminate is connected to at least the bottom flange and the web portion of the rail to an underside of the top flange of the rail on each side of the rail. 26. The method according to claim 20, further including the step of calendering or extruding individually each layer of the laminate followed by calendaring the layers together prior to curing to form the laminates, and wherein the calendering or extrusion, or a combination thereof, is conducted at a temperature below the activation temperature of a blowing agent utilized in the closed cell foam rubber layer. 27. The method according to claim 26, wherein the laminate is cured in an autoclave at a temperature of about 121° C. to about 177° C. and at a pressure of about 775 mm of mercury to about 6206 mm of mercury. 28. The method according to claim 27, when the curing temperature is from 137° C. to about 160° C., and wherein the pressure is about 1396 mm of mercury to about 4654 mm of mercury. 29. The method according to claim 20, further including the step of connecting the composite rail to a street or rail bed.