Additives, oil filter, machinery lubrication system

The present invention is an additive that is added to the oil, to provide an additive comprising a weakly basic hydrotalcite. Weakly basic hydrotalcite, to the oil the hydrogen ion exponent is within the range of 6-7, when stirring was added a mixture of 1 wt% of hydrotalcite and water 3% by weight, the resulting oil is hydrotalcite showing the hydrogen ion exponent in the range of 6-7. Then, such additives may be used is accommodated in the oil filter (36).