| 摘要 |
940,424. Reflex reflectors. MINNESOTA MINING & MANUFACTURING CO. Feb. 4, 1960 [Feb. 4, 1959], No.4016/60. Heading G2J. [Also in Division B2] A reflex reflector comprises a backing to which reflex reflecting beads are bonded, the beads having a refractive index of approximately 1.9 and having specular reflecting means in contact with their undersides and the binder layer including a flatting agent so that the binder layer surface between the beads is substantially flat. As shown in Fig. 3, the reflex reflector comprises a backing sheet 30 having on one surface a pressure sensitive adhesive layer 34 with a temporary linear 35. A base film 31 is provided on the other surface of the backing 30 and bonded to this base film by a layer 33 are glass beads 36 having a specular reflecting coating 37 on their undersides. The backing layer 30 is preferably formed by coating a solution of polyvinyl butyral resin in ethyl "Cellosolve" (Registered Trade Mark) upon a polystyrene coated paper. The base film 31 and the bonding layer 33 are preferably formed from a mixture of an oil modified alkyd varnish solution, melamine formaldehyde resin, phthalo cyanine blue pigment, silica aerogel and metal napthanate dryer solution. Over the tacky surface so formed, a free flowing mass of silvered indigo blue beads are passed and the beads pressed into the tacky coating up to about 40% of the diameter. Preferably these beads have a transmission range in the region 4000 to 5200 Angstrom units. The silver on the exposed parts of the beads is finally etched away. |
