Abstract: Polyimides or poly(amide-imides), especially those containing a polysiloxane unit are improved by heating such polymers or their polyamic acid precursors with a polyfunctional aromatic compound. The polyfunctional aromatic compound is one which contains at least two reactive groups which may be --NH.sub.2, --COOH, --OH or secondary amino groups with at least one of the reactive groups being --NH.sub.2 or --COOH.

Abstract: Copper substantially free of micro-pores is electrodeposited on a polished surface of a stainless steel, titanium, or chromium-plated steel press plate. The copper layer is then provided with a matte surface of copper of dendritic structure which is subsequently bonded to a dielectric material under the application of heat and pressure in a laminating press. The resulting copper-clad dielectric board separates from the press plate, which can then be re-used.

Abstract: An activation composition and method for producing chromium electrodeposits having excellent adhesion on both soft and hardened ferrous substrates from high energy efficient chromium baths is described. The activation composition is a solution containing iodate and fluoroborate ions, optionally with cerium ion as a stabilizer. The method includes electrolytically etching the substrate in the activation solution, preceded or followed by reverse etching in chromic acid. The chromium electrodeposit can be carried out effectively to provide the desired adherent deposit from a high energy efficient (HEEF) chromium plating bath.

Abstract: An apparatus for applying a phototool to a light sensitive substrate by means of a roller for applying the phototool to the substrate and a vacuum restraining means for restraining the phototool to maintain it under tension during application of the phototool to the substrate.

Abstract: A novel polymeric binder for use in an antifouling paint includes an acrylic or methacrylic ester monomer having selected substituted aryl or arylalkyl substituent groups in the ester moiety so that the ester is hydrolyzable at a suitable rate in seawater, and a copolymerizable ethylenically unsaturated monomer unit.

Abstract: An activation solution is provided for forming adherent chromium electrodeposits on metal substrates, preferably ferrous metals such as cast iron, from high energy efficient chromium baths. The solution suitably is a mixture of sulfuric acid, added sulfate ion, and an inorganic oxidizing agent. A preferred solution contains 10 to 40% by volume concentrated sulfuric acid, 100 to 200 grams per liter of magnesium sulfate heptahydrate and 1 to 2 grams per liter of sodium nitrate.

Abstract: An activation solution is provided for forming adherent chromium electrodeposits on stainless steel substrates from high energy efficient chromium baths. The activation solution suitably is a mixture of chromium acid, and chloride ion, or a mixture of chloride and bromide ions. A preferred solution contains 0.15M chromic acid and 0.14M chloride ion, or with 0.025M bromide ion, and the stainless steel is anodically etched in the activation solution at about 55.degree. C.

Abstract: A process for stripping a deposit comprising nickel or a nickel-iron alloy from a substrate metal which comprises immersing the substrate metal with deposit thereon into a stripping bath comprising an aqueous stripping solution comprising chromic acid, utilizing said substrate metal as either or both the anode and cathode of an electrolytic stripping cell and applying an alternating current across the electrodes for a time sufficient to strip the deposit from the substrate metal is disclosed.

Abstract: A method of converting at least partially molten dibutyltin difluoride contained in a hot, waste gas stream into substantially dry, solid particles suitable for recovery by filtration through a porous bag filter. The method includes the steps of introducing a predetermined amount of liquid water into the stream, and vaporizing the liquid water to cool the gas and the molten dibutyltin difluoride to form substantially dry particles. The amount of liquid water is sufficient to effect the desired cooling without saturating the gas stream.

Abstract: A printed circuit board having improved adhesion between solder mask and metal includes a primer film on the metal deposited from an aqueous solution which includes 0.01 to 10% by weight of a carboxyl-containing polymer or copolymer.

Abstract: A method and composition for increasing the cure depth of a solder mask coating at a low UV energy level. The stable composition, which includes a UV curable compound and a photoinitiator, is characterized by the presence of triphenylphosphite in the composition.

Abstract: A method of modifying the properties of siloxane-containing polymers is provided which comprises heating said siloxane-containing polymer in the presence of an organic alcohol, a phenol or a thiol which contains at least two reactive hydrogen-containing groups.