German leather chemical manufacturers, Boehme, have introduced a synthetic retanning agent and three fatliquors. They are as follows:

Tannit STP: A synthetic replacement tanning agent made from a condensation product of methylene linked nitrogen containing hydroxy aryl sulfonic acids. The anionic, brown liquid has a concentration of 50% and a pH4.0-5.0 in a 10% aqueous solution. STP has been specifically designed to be used in the retannage of pastel shade leathers for shoe upper, upholstery and ovine garment nappa. It provides the leather with good softness and fullness with a light, white colour. STP improves the leather firmness and has good lightfastness.

It is resistant to electrolyte and pickle solutions at normal concentrations and can be added diluted or undiluted with water to the process floats. Tannit STP is recommended to be offered proportionally up to 10% based on shaved weight.

Cutapol ELS: A fatliquor made up from ester sulfonates, modified vegetable oils and high molecular aliphatic hydocarbons. The dark brown, anionic liquid has a 92% concentration and is to be used mainly in combination with other fatliquors. Cutapol ELS renders the leather with high softness, improved tear resistance, a full and waxy feel, and a reduced water absorbing capacity.

This product can be used on all types of leather and provides the final article with an intensified gloss and a rounded grain following milling.

It has a pH of 5.5-7.7 in a 10% aqueous solution and has to be pre-emulsified with warm or hot water before added to floats. The electrolyte resistance depends on the resistance of the other products used.

Cutapol TIS-OC: Boehme have designed this fatliquor to be specifically used on aniline leathers. The beige to brown liquid is made up of ester sulfonates, fish oil derivatives and high molecular aliphatic hydrocarbons. The anionic substance is resistant to electrolytes in normal concentrations and has a pH of 7.0-9.0 in a 10% solution.

Cutapol TIS-OC offers good exhaustion, an excellent waxy handle with very good dyeability and levelness. As TIS-OC offers good lightfastness, it is suitable for all soft clothing and upholstery leathers as a pure fatliquor. It can be added diluted or undiluted with water to process baths.

Cutapol TLL: A second fatliquor from Boehme suitable for lubricating aniline leathers, TLL, has been designed to be used on all soft garment and upholstery leathers as a main fatliquor. The orange liquid is a mixture of natural and synthetic sulfoester derivatives, sulfitates of animal oils and high molecular aliphatic hydrocarbons.

This product is resistant to electrolytes in usual tannery concentrations but is not resistant to strong acids. The anionic oil has a concentration around 65% and can be added undiluted or diluted with water to the process float.

Cutapol TLL offers the leather a full and rounded handle with good lightfastness and levelness. It offers outstanding softness and good buffability.