Other

Macdermid Acumen, Inc.

Roderick Dennis Herdman

Trevor Pearson

Roshan V Chapaneri

Stacey Handy

Richard Tooth

Terence Clarke

Alison Hyslop

Ernest Long

Anthony Rowan

Toshiyuki Yamamoto

Kotaro Ishiwata

Marc Mertens

Masahiro Hara

Tatsuya Nishiyama

Alan Gardner

Anthony Wall

Stacey L Handy

A method of regenerating an etch solution comprising a metastable complex of manganese(III) ions in a strong acid is described in which at least a portion of the manganese(III) ions in the metastable complex have been destabilized, causing them to disproportionate into manganese dioxide and manganese(II) ions. The method includes the steps of i) adding an effective amount of a reducing agent to the solution; ii) allowing the reducing agent to react with the solution to cause manganese dioxide to dissolve; and (iii) applying an electrical current to regenerate manganese(III) ions in the solution.

Regeneration of etch solutions containing trivalent manganese in acid media

A method of treating a substrate, wherein the substrate comprises a layer deposited from a trivalent chromium electrolyte, is described. The method includes the steps of providing an anode and the chromium(III) plated substrate as a cathode in an electrolyte comprising (i) a trivalent chromium salt; and (ii) a complexant; and passing an electrical current between the anode and the cathode to passivate the chromium(III) plated substrate. The substrate may be first plated with a plated nickel layer so that the chromium(III) plated layer is deposited over the nickel plated layer.

Passivation of micro-discontinuous chromium deposited from a trivalent electrolyte

A method of coating an electroplating rack used for supporting non-conductive substrates during a plating process. The method comprises the steps of contacting at least a portion of the electroplating rack with a plastisol composition, the plastisol composition having dispersed therein an effective amount of an additive; and heating the electroplating rack with the plastisol composition thereon to a suitable temperature and for a sufficient time to cure the plastisol and form a solid insulating coating on the electroplating rack. The coated electroplating rack may then be used for mounting non-conductive substrates for subsequent metallization steps.

Treatment for electroplating racks to avoid rack metallization

The invention consists of a chromium electroplating solution comprising a chromium electroplating solution comprising: (1) a water soluble trivalent chromium salt; (2) at least one complexant for trivalent chromium ions; (3) a source of hydrogen ions sufficient to create a pH of from 2.8-4.2; (4) a pH buffering compound; and (5) a sulfur-containing organic compound. The chromium electroplating solution is usable in a method for producing an adherent metallic coating on a decorative article, such coating having enhanced resistance to corrosion in environments containing calcium chloride.

Chromium alloy coating with enhanced resistance to corrosion in calcium chloride environments

An aqueous acidic trivalent chromium electrolyte comprising trivalent chromium ions and a complexing agent for maintaining the trivalent chromium ions in solution is provided in which the aqueous electrolyte comprises additives capable of producing a coating on a substrate having a desired dark hue. The additives typically comprise a dispersion of colloidal silica and an additional additive selected from thiocyanate ions and/or iron ions. The electrolyte is used in a method of producing the desired dark-hued decorative chromium coating on a substrate by electrodeposition.

Dark colored chromium based electrodeposits

Pulse reverse electrolysis of acid copper solutions is used for applying copper deposits of a controlled hardness for applications such as producing printing cylinders. The benefits include improved production capacity. Hardness of the deposit is controlled by varying at least one factor selected from the group consisting of (i) cathodic pulse time, (ii) anodic pulse time, (iii) cathodic pulse current density, and (iv) anodic pulse current density. Preferably the ratio of cathodic pulse time to anodic pulse time is varied.

Controlling the hardness of electrodeposited copper coatings by variation of current profile

An electroplating bath medium for electroplating articles with a tin-cobalt, tin-nickel, or tin-cobalt-nickel alloy comprises: at least one tin salt; an alloying metal salt comprising a cobalt salt and/or a nickel salt; a complexant comprising a hydroxycarboxylic acid or alkali metal salt thereof such as a sodium or potassium gluconate or heptonate complexant; boric acid; and a bath soluble substituted phenolic compound. The current regime applied to the plating bath can include time intervals of direct current and of pulsed current in order to selectively control the deposition of tin by activation or diffusion control.

Electrolyte media for the deposition of tin alloys and methods for depositing tin alloys

The present invention is directed to an improved copper plating bath for depositing a copper layer onto a printing cylinder, the copper plating bath comprising: (a) a source of copper ions; (b) a source of methane sulphonate ions; (c) a source of chloride ions; (d) an organosulphur compound having the formula R&#x2014;S&#x2014;R'&#x2014;SOXor X&#x2014;OS&#x2014;R&#x2032;&#x2014;S&#x2014;R&#x2014;S&#x2014;R&#x2032;&#x2014;SO&#x2014;X, wherein R is alkyl, hydroxyalkyl or alkyl ether, R&#x2032; is a C&#x2013;Calkyl group, and Xis a cation; and (e) a polyether compound and method of using the same. The copper plating bath produces a plating deposit that has a stable hardness and is free from self-annealing during high speed plating.

Copper electroplating of printing cylinders

An additive for an alkaline zinc or zinc alloy electroplating bath medium, the additive comprising a random co-polymer comprising the reaction product of: (i) one or more di-tertiary amines including an amide or thioamide functional group, and (ii) optionally, one or more saturated second di-tertiary amines and/or one or more second di-tertiary amines including an unsaturated moiety, with (iii) one or more saturated or unsaturated linking agents capable of reacting with said di-tertiary amines (i) and (ii), provided that, where all the linking agents are saturated, an unsaturated di-tertiary amine must he present. Preferably, the polymer has the general formula n(2x+2y+zE)j-.

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Staffordshire, United Kingdom

Roderick Dennis Herdman