Abstract: A film sealant useful for tightly sealing an electric device at a low temperature and a sealing method of using the sealant are provided. The device is covered and sealed by covering at least a region of the device with a film sealant containing a copolyamide-series resin, heat-melting the sealant, and cooling the sealant. The copolyamide-series resin may have a melting point or softening point of 75 to 160° C. and may be a crystalline resin. The copolyamide-series resin may be a multiple copolymer or may contain a unit derived from a long-chain component having a C8-16alkylene group (e.g., a C9-17lactam and an aminoC9-17alkanecarboxylic acid). The film sealant may cover one side of the device.

Abstract: A film sealant useful for tightly sealing an electric device at a low temperature and a sealing method of using the sealant are provided. The device is covered and sealed by covering at least a region of the device with a film sealant containing a copolyamide-series resin, heat-melting the sealant, and cooling the sealant. The copolyamide-series resin may have a melting point or softening point of 75 to 160° C. and may be a crystalline resin. The copolyamide-series resin may be a multiple copolymer or may contain a unit derived from a long-chain component having a C8-16alkylene group (e.g., a C9-17lactam and an aminoC9-17alkanecarboxylic acid). The film sealant may cover one side of the device.

Abstract: A mirror comprising:a transparent plate of a synthetic resin;a surface-hardening layer (a) coated on an entire surface of the resin plate;a reflective metal layer (b) deposited on the layer (a) of the back of resin, anda back-coat layer (c) closely covering the surface of the reflective film, characterized in that said metal layer is formed by a dry metal plating, said metal being selected from the group consisting of tin or alloy of tin and copper (Sn:Cu=1:less than 0.4 by weight), thickness of layer (b) being in the range of 700-1600 .ANG. and moisture permeability of layer (a) being smaller than those of layer (b) and layer (c) is disclosed.

Abstract: A mirror which utilizes a transparent synthetic resin such as a polymethyl methacrylate resin in place of glass and is suitable, e.g., as an automobile inside rearview mirror. The back side of the resin plate is coated with a reflective metal film by vacuum deposition, and at least the front side of the resin plate is coated with a surface-hardening film, which is inevitably somewhat permeable to humidity. To prevent warping of the resin plate resulting from its moisture absorption and swelling only in its front region, the reflective film and a back-coat layer covering this film are both made permeable to humidity substantially equally to the surface-hardening film. Preferred material for the reflective film is a Sn--Cu--Cr ternary alloy having high reflectivity and excellent resistance to moisture.

Abstract: A low-loss optical fiber core for optical communications is covered with at least one layer of a polylaurolactam copolymer composed of 20 to 98 parts by weight of laurolactam and 80 to 2 parts by weight of a polyamide-forming monomer other than laurolactam, said copolymer having a melting point within a range of 100.degree. C. to 170.degree. C.