| 摘要 |
1444668 Sealing porous metal objects GENERAL TIRE & RUBBER CO 4 Oct 1974 [18 Oct 1973] 43142/74 Heading B2E A method of sealing the surface of a porous metal object with a thermosetting resin comprises, (i) heating the porous metal object to an elevated temperature above the curing temperature of the resin for sufficient length of time to raise the temperature of the gases within the pores of the metal object substantially to the elevated temperature, (ii) applying to the surface a dry powder comprising a major proportion by weight of resin and not more than 20 wt % filler (e.g. talc), (iii) reducing the temperature of the object to the curing temperature of the resin whereby gas in the porous metal object cools and contracts to draw in the resin, and (iv) maintaining the object at the curing temperature until the resin cures to form a coat which traps the gas in the pores. The sealed object may then be primed with adhesive and bonded to rubber or coated therewith. Generally the curing temperature is from 50 to 150‹F and the powder may be applied by electrostatic spraying, fluidised bed or electrostatic fluidised bed. In Examples (1), (2), metal objects are electrostatically sprayed with blue epoxy resin powder containing a filler then, after the curing steps, are futher spray coated with two coats of a solution of epoxy adhesive from which the solvent was evaporated, before being vulcanisation bonded to an elastomer, (3) as in (1) but a green epoxy resin powder was substituted for the blue, (4) as in (1) but without the filler. A list of natural and synthetic elastomers, suitable for bonding is given. |
