| 摘要 |
1421985 Coated cylindrical objects LOCTITE CORP 14 Feb 1973 [14 Feb 1972] 7189/ 73 Heading B2E [Also in Division F2] A process for coating cylindrical objects which comprises applying a spreadable coating composition containing a first reactant to at least a portion of the surface of the cylindrical objects and rotating each object to obtain at least a band of coating composition round it and subsequently contacting that portion of the surface coated with the coating composition with a congealing agent containing or consisting of a second reactant capable of reacting with the first reactant to congeal at least the surface of the coating composition. The cylindrical object is preferably a threaded fastener such as a stud, bolt or wood screw, but may be a threaded pipe connector or rivet. The coating compositions may be a solution or dispersion of a thermoplastic polymer having "active hydrogen atoms" such as ponlyvinylalcohol, polyvinyl acetal (e.g. butryal or formal) and polyvinyl esters (e.g. acetate), the polymer serving as "first reactant". The composition may in addition contain encapsulated anaerobic adhesive or sealant such as epoxy and a hardener. The second reactant, applied preferably as a solution, may consist of (i) inorganic polyfunctional acids e.g. borax or silicic acid, (ii) hydrogen bonding compounds e.g. cotton-fast dyes such as congo red; polyhydroxy aromatic compounds such as resorcinol; salicyl analides; or phenol acids, e.g. gallic acid or dihydroxy benzoic acid, (iii) cross-linking agents such as aldehydes or methylolated amides, (iv) metal hydroxides such as copper hydroxide, titanium hydroxide or tin hydroxide, or precursors for them, such as supous chloride or tetraisopropyltitanium or (v) strongly complexing salts of transition metals such as cupric ammonium chloride. The cylindrical objects can be coated by dipping, padding or spraying. Also mentioned are aluminium powder (colouring agent) and graphite (lubricant) incorporated in the coating compositions. |
