The present invention refers to an electroplating bath for depositing chromium which comprises at least one trivalent chromium salt, at least one complexing agent, at least one halogen salt and optionally further additives. Moreover, the invention refers to a process for depositing chromium on a substrate using the mentioned electroplating bath.

The present invention refers to an electroplating bath for depositing chromium which comprises at least one trivalent chromium salt, at least one complexing agent, at least one halogen salt and optionally further additives. Moreover, the invention refers to a process for depositing chromium on a substrate using the mentioned electroplating bath.

An apparatus for maintaining trivalent chromium plating bath efficiency includes an aqueous electroplating bath, which includes trivalent chromium ions and a sulfur compound, and an ultraviolet (UV) radiation source that provides UV radiation to the bath effective to inhibit a reduction in plating efficiency of the bath.

There is provided an electrolyte for the electrodeposition of chromium comprising: (A) water; (B) at least one chromium salt; and (C) at least one complexing agent,
wherein the molar ratio of components B:C is in the range of 1:1 to 1:50. There is also provided a method for electrodepositing chromium metal onto a conductive substrate.

There is provided an electrolyte for the electrodeposition of chromium comprising: (A) water; (B) at least one chromium salt; and (C) at least one complexing agent,
wherein the molar ratio of components B:C is in the range of 1:1 to 1:50. There is also provided a method for electrodepositing chromium metal onto a conductive substrate.

The invention relates to a method for the adjustment of the lightness L* of electrolytically deposited chromium-finishes on workpieces obtained by an electroplating bath comprising at least chromium(III)-ions and sulfur containing organic compounds, wherein the concentration of the sulfur containing organic compounds in the bath are adjusted by passing at least part of the bath composition through an activated carbon filter. Furthermore, the invention is directed to dark chrome coatings comprising a defined concentration gradient of deposited sulfur containing organic compounds.

The invention relates to a method for the adjustment of the lightness L* of electrolytically deposited chromium-finishes on workpieces obtained by an electroplating bath comprising at least chromium(III)-ions and sulfur containing organic compounds, wherein the concentration of the sulfur containing organic compounds in the bath are adjusted by passing at least part of the bath composition through an activated carbon filter. Furthermore, the invention is directed to dark chrome coatings comprising a defined concentration gradient of deposited sulfur containing organic compounds.

The present invention refers to an electroplating bath for depositing chromium which comprises at least one trivalent chromium salt, at least one complexing agent, at least one halogen salt and optionally further additives. Moreover, the invention refers to a process for depositing chromium on a substrate using the mentioned electroplating bath.

The present invention refers to an electroplating bath for depositing chromium which comprises at least one trivalent chromium salt, at least one complexing agent, at least one halogen salt and optionally further additives. Moreover, the invention refers to a process for depositing chromium on a substrate using the mentioned electroplating bath.

The present invention relates to beta-naphthol ether sulfonic acids or salts thereof having the general formula (I) RO-(AO).sub.nCH.sub.2CH.sub.2S(O).sub.3M (I), where R, AO, n and M have the definitions stated in the claims and in the description, to mixtures thereof, to aqueous solutions and to electrolytes comprising them, to processes for preparing them and to the use of these.