International Lead Zinc Research Organization, Inc.

Bnf Metals Technology Centre

The Gillette Company

Clive Barnes

John J Ward

Mark Arthur Seddon

Charles Christopher Packham

Alan Robert Hill

Susan Smith

Roger Francis

A marking instrument, such as a pen, is disclosed. The marking instrument includes a marking tip carried at the end of a tubular member for conducting marking fluid to the marking tip. The marking tip includes a tubular rear end section of circular cross-section. The tubular member is elliptical in cross-section and is attached to the tubular rear end section of the marking tip at an angle to the longitudinal axis of the tubular member. The elliptical shape of the tubular member allows for a circular profile opening when the tubular member is cut at an angle to join the tubular rear end section of the marking tip. Because the complementary profiles are circular in shape at the connection plane, it is not necessary to rotationally orient the components when bringing them together to be joined. The tubular rear end section of the marking tip may also be elliptical in shape, thereby requiring both the tubular rear end section and the tubular member to be cut at similar angles to produce the circular profile opening.

Marking instruments

A ball point pen has a hollow nib member (2) attached to the end of a cylindrical body (1) enclosing a ink reservoir (3), the forward end of the nib member being spaced from the axis (B) of the body and having a tip element (4) welded thereto so that the writing ball (6) incorporated in the tip is located on the same side of the axis (B) as the forward end of the nib member.

Ball point pen

The treatment of the external surfaces of condenser tubes, such as those used in power station condenser plants, with certain inorganic chemical compounds renders those surfaces or parts thereof sufficiently water-repellent so as to prevent the formation thereon, during operation of the condenser, of condensate films. Instead of continuous condensate films forming on the treated condenser tube surfaces during operation of the condenser, condensation is formed as discrete droplets of water which run down and drip off the tubes with the result that the condenser plant can work at higher levels of efficiency. Suitable chemical substances for use in the treatment of condenser tube surfaces include Cr VI anions, Cr.sup.3+ ions, and alkali metal tungstates, vanadates and molybdates.

Treatment of condenser tubes

An electrolyte solution and the method of using same for electrodeposition of black chromium on a substrate, said solution comprising water, trivalent chromium ions, ions of a metal selected from the group consisting of iron and cobalt, a weak complexing agent for the trivalent chromium ions, and phosphate ions. The preferred complexing agents are hypophosphite or formate.

Electrodeposition of black chromium

A method of depositing a protective chromite conversion coating is described. The chromite coatings produced by the method contain no Cr.sup.VI. The electrolyte used in the method comprises Cr.sup.III ions in a concentration of not more than 1 molar and a weak complexing agent for Cr.sup.III ions. The electrolyte, preferably, also contains conductivity salts. The method involves using a cathode current density of not more than 2000 amps per square meter and a temperature of not more than 35.degree. C. for a period of not more than 3 minutes. The chromite conversion coatings can be improved by aging and can be subsequently painted or lacquered. The Cr.sup.III electrolytes used are much less corrosive than Cr.sup.VI electrolytes and thus the substrates which can be coated include materials which cannot readily be chromate coated because they are reactive towards Cr.sup.VI electrolytes.

Electrolytic formation of chromite coatings

A nickel electroplating bath comprises in aqueous solution at a pH of from 4 to 7, nickel ions at a Molar concentration of at least 0.25, chloride ions at a Molar concentration of at least 0.25, and a weak complexant for the nickel selected from formate, acetate, citrate, glutamate, anions and lactones of sugar acids and anions and lactones of acids having the formula X(C.sub.n H.sub.2n)COOH where X is OH or NH.sub.2 and n is 1 to 5, preferably 1 to 2, present at a Molar concentration of from 0.5 to 4.0 times that of the nickel. These baths have good throwing power and can be operated at convenient temperatures and pH values and at lower nickel ion concentrations than hitherto.

Nickel plating

A method whereby a surface of chromium metal electrodeposited on a zinc substrate from a trivalent chromium electrolyte is treated by contacting the surface with an aqueous solution at a pH of from 5 to 12 and containing a dissolved metal salt of a weak acid which does not form a soluble complex with zinc. Preferred salts are carbonates, phosphates and silicates of an alkali metal, e.g. sodium or potassium. Also disclosed is the product of said process comprising an article having a zinc substrate, a microporous electrodeposited chromium coating from 0.025 to 2.5 microns in thickness on said substrate, and a water-insoluble basic salt of zinc within the micropores.

Treatment of chromium electrodeposit

An electrolyte bath and a method for using such a bath comprising trivalent chromium ions dissolved in an aqueous solution containing sulphide. The bath may also contain a weak complexing agent such as hypophosphite or glycine. The electrolyte according to the invention permits the electrodeposition of chormium from electrolytes having low solids content without adversely affecting plating rates.

Trivalent chromium plating baths

A method of producing chromium conversion coatings is described. The coatings are novel in that they are chromite i.e. Cr.sub.2 O.sub.3 coatings rather than the conventional chromate i.e. CrO.sub.3 coatings. The invention includes a novel electrolyte for depositing chromite layers. The electrolyte is an aqueous solution containing Cr.sup.III ions, a weak complexing agent for Cr.sup.III ions and a poison for the electrodeposition of chromium metal. The electrolyte preferably also contains conductivity salts and may include other additives such as fluoride ion and boric acid. Examples of poisons are Cr.sup.VI ions, peroxide, nitrate, polyamines, phosphates and formaldehyde. The chromite conversion coatings can be improved by aging and can be subsequently painted or lacquered. The electrolytes of the present invention are much less corrosive than Cr.sup.VI electrolytes and thus the substrates which can be coated include materials which cannot readily be chromate coated because they are reactive towards Cr.sup.VI electrolytes.

Chromite coatings, electrolytes, and electrolytic method of forming the

An aqueous trivalent chromium plating bath having low temperature stability comprising trivalent chromium ions preferably in a concentration of at least 0.2 M, sulphate ions preferably in a concentration of at least 0.3 M, a weak complexing agent for the chromium ions in a concentration of at least 0.1 M, and fluoride ions in a concentration of at least 0.025 M. The bath preferably also contains chloride ions in a concentration of at least 0.1 M.

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Wantage, United Kingdom

Clive Barnes