Apiezon Waxes

High vacuum joints of a more permanent nature, not required to be movable, are best sealed with one of the Apiezon® waxes rather than by a grease. Three grades of wax are available, all basically similar, but differing in their hardness and softening points, from hard Wax W softening at 80′ to 90’C to relatively soft Wax W40 softening at about 40’C. Wax W would be chosen for sealing most joints; a softer grade is used where the lower softening point makes application easier or where the softer wax is desirable because of probable vibration of the joint.

Apiezon® waxes have powerful gettering’ properties similar to the greases. This coupled with their purity and very’clean’meltdown characteristics has led to their extensive use in the electronics industry. Apiezon waxes are used in the manufacture of silicon transistors and integrated circuits, both as miniature mounting blocks (in the form of small chips) and by deposition from a solution in a suitable solvent, as the masking medium in etching processes. Their extreme chemical inertness makes them very resistant to etching fluids such as hydrofluoric acid, nitric acid, acetic acid, but they are easily and rapidly removed by hydrocarbon or chlorinated solvents.

Specifications Table:

Apiezon® Waxes Technical Data	Wax W40	Wax W100	Wax W	Compound Q
Approximate softening point, degrees C	45	55	85	45
Temperature for application, degrees C	90	110	130	Ambient
Maximum temperature for use, degrees C	40	50	80	30
Specific gravity at 20 deg.C/15.5 deg.C	1.017	1.567	1.055
Specific gravity at 30 deg.C/15.5 deg.C	1.010	1.561	1.048
Average molecular weight	1140	1160	1214
Coefficient of expansion per deg.C over 20 deg.C-20 degC	0.00063	–	0.00062
Thermal conductivity Btu. in/ft2h degrees F	1.23	1.18	1.31
w/m degrees C	0.177	0.170	0.189
Specific heat at 25 degrees C, cal/g	0.51	0.70	0.43
Joule/g	2.1	2.9	1.8
Loss tanget	0.015	0.016	0.015
Permittivity	2.9	2.7	2.8
Volume resistivity, ohm/cms	5.055×1015	1.64×1015	6.31×101