The present invention concerns a tapping lubricant.
A tapping lubricant is a lubricant that is used in tapping operations that c internal screw threads in objects such as engine blocks.
Tapping lubricants usually contain chlorinated paraffins and sulphurised esters, These lubricants, however, generally have a bad odour, ate toxic and hazardous to the environment, and are unpleasant to use
The. aim of the present invention is to provide a tapping lubricant that is frfee from chlorine and sulphur.

The ami of the present invention is also to provide a tapping lubricant tlia contains no boron; is free from other known hazardous materials, is non-toxic; has high performance and is suitable for stainless steel and copper alloys; has low odour; and performs well in arduous operations such as, for example, with alloy steels and aluminium.
In accordance with the present invention there is provided a tapping lubricant comprising an aqueous wax dispersion, a phosphate ester and an ester that is not a phosphate ester.
The tapping lubricant of the present invention is free from chlorine and sulphur. It is also free from boron; is non-toxic; exhibits high performance with stainless steel and copper alloys; has low odour; and performs well with, for example, alloy steels and aluminium used in the automotive industries.

The tapping lubricant preferably comprises from 50-90%, preferably from 60-80%, by weight of the aqueous wax dispersion, from 2-10%, preferably from 4-8%, by weight pf the phosphate ester and from 5-20%, preferably from 10-20%, by weight of the ester that is not a phosphate ester.
The ester that is not a phosphate e&tar is preferably an ester of a polyhydric alcohol. Examples of suitable esters are pentaerythntol esters, trimethylolpropane esters, neopentylglycol esters and triglyceride esters.
The wax dispersion is preferably based on polyethylene glycol
The phosphate ester is preferably an alkylarylpolyethelenoxy phosphate ester with a phosphorus content of between 4 and 6%.
The tapping lubricant may be in the form of a liquid, a paste or a solid. The lubricant is preferably in the form of a paste.
The tapping lubricant may be applied using a spray, a brush or an aerosol.
The invention will now be described with reference to the following
! ' ■
example:
Example
The following tapping lubricant was prepared;


ffentaerythrjol monooleate 14 20
(available from Croda or Fina)
liubrophos LP700 7 05
(available from Rohn Poulenc)
Triethanol amine 7 90
(available from BP, Texaco, Union Carbide or Dow Chemical)
Imazalil solution (70% in monoethylene glycol) 0.05
(available from Janssen Chemica)
The Hordamer was added to a mixer having an efficient stirrer, tor example, a grease blender or a Z-blade. The other components were slowly added to the mixer with constant mixing in the order in which they appear above. Mixing was continued until the mixture was fully homogeneous and the required consistency was achieved.
Tests
The tapping lubricant was tested on stainless steel (316) 012, depth 30rnm using a staight tap (Tidex Plus B1344, M12). The spindle speed was 180 rpm. As a comparative example, the test was also carried out on a tapping lubricant known as Rocol RTD.
Test Results
Tapping Lubricant Number of Taps
Present invention 325 taps
Rocol RTD* 5 10 taps
* Rocol RTD is available from Rocol Ltd. Rocol RTD is a tappiny lubricant thjat comprises chlorinated paraffins and sulphurised ester

The results show that the tapping lubncant of the present invention exhibits good performance.
It was observed in the test that the tapping lubricant of the present invention produced less smoke and heat than the tapping lubricant knowi as Rocol RTD. The tapping lubricant of the present invention was also found to be more gentle to the skin than the Kocol RID.

we claim
1. A tapping lubricant comprising an aqueous wax dispersion, a
phosphate ester and an ester that is not a phosphate ester.
2. The tapping lubricant claimed in claim 1, comprising from 50-00%
by weight of the aqueous wax dispersion, from 2-10% by weight of the
phosphate ester and from 5-20% by weight of the ester that is not a
phosphate ester.
3. Use of the tapping lubricant claimed in claims 1 or 2, in a tapping
operation
4. A tapping lubricant substantially as hereinbatote
described.
5. Use of the tapping lubricant substantially as
hereinbefore described.