| 摘要 |
1491202 Coated products WARNE SURGICAL PRODUCTS Ltd 8 Oct 1974 [17 Oct 1973] 48441/73 Heading B2E A method of making a catheter or tube useful for medical or surgical purposes having at the patient end (as defined) a coating of a finely-divided, highly X-ray opaque substance, in which to the patient end is applied a paste which comprises a finely-divided substance which is high in opacity to X-rays and which has a particle size of not greater than one micron, dispersed in a solution of a synthetic polymer dissolved in at least one organic solvent which is evaporatable and which will soften the synthetic plastics material of which the patient end is made, and allowing the solvent to evaporate thereby to form the coating. The coating may be formed by transfer printing, brushing, spraying or, preferably, dipping. The synthetic polymer solution is preferably saturated, and the weight of X-ray opaque substance is preferably about equal to that of the synthetic polymer. The synthetic polymer is preferably polyvinylchloride or polyurethane, the X-ray opaque substance is preferably bismuth, precipitated barium sulphate or tungsten, and the solvent is preferably cyclohexanone, methyl ethyl ketone, tetrahydrofuran or mixtures thereof. In the Examples; the synthetic polymer is (1) polyvinylchloride, (2) polyurethane; the X-ray opaque substance is (1) (2) bismuth, precipitated barium sulphate, tungsten, the solvent is cyclohexanone and/or methyl ethyl ketone, (2) tetrahydrofuran; the tubing is (1) (2) polyvinylchloride, (2) polyurethane. |
