The invention discloses a method for treating an animal substrate comprising: agitating the moistened animal substrate with a treatment formulation and a solid particulate material in a sealed apparatus wherein the treatment formulation comprises a tanning agent or a tannery process agent. The method can comprise applying the tanning agent or tannery process agent to the animal substrate wherein at least some of the agent so applied originates from the treatment formulation. There is also disclosed an animal substrate obtained by the method. The treatment formulation can be aqueous.

A method of preparing hydrophobicizing leather treatment compositions includes the steps of a) free-radically initiated copolymerization of i) at least one ethylenically unsaturated carboxylic acid or its derivatives, and ii) at least one (meth)acrylate of a primary saturated C.sub.8 to C.sub.22 alcohol, b) mixing the reaction mixture obtained after step a) with water, c) salting at least some of the carboxyl groups of the reaction mixture obtained after step b) with a base, and d) shearing the reaction mixture obtained after step c) to an average particle size of 0.05-10 m,
wherein step a) is carried out in oil as reaction medium and wherein the atmosphere in step a) contains less than 0.1% by volume of an oxidizing gas.

The present invention discloses a process for preparing a flame-retardant, lightfast, low fogging and degradable car seat leather wherein ammonia salt deliming is replaced with an ammonia free one, tetrakis hydroxymethyl phosphonium sulfate and the flame-retardant starchy leather surfactant are used as the tanning agents to replace the conventional chrome tanning agent, hot water washing is used to reduce the fogging value of the seat leather, the flame-retardant performance is enhanced by combination of retanning, greasing and coating, the lightfast material is applied to enhance the lightfastness of the coating and the spray coating is replace with the roller coating to lower the consumption of the paints.