AN IMPROVED MANUFACTURE or INSULATING COMPOUNDS APPLICABLE ALSO TO OTHER PURPOSES
Year: 1882

page_text: LETTERS PATENT to Murdoch Mackay of Mansion Street, in the county of
Surrey, Chemist for an Invention of "AN IMPROVED MANUFACTURE or
INSULATING COMPOUNDS APPLICABLE ALSO TO OTHER PURPOSES
"
}
PROVISIONAL SPECIFICATION left by the said Murdoch Mackay at the
Office of the Commissioners of Patents on the 5th July 1882.
MURDOCH MACKAY of Mansion Street, in the county of Surrey Chemist,
"AN IMPROVED MANUFACTURE OF INSULATING COMPOUNDS APPLICABLE ALSO TO
OTHER PURPOSES
"
This invention relates to the manufacture of improved compounds or compositions
for electric insulation also applicable for forming moulds for electro deposition for
electro plating and for copying wood cuts in copper by the electro process also for
copying set up type, engravings and the like.
In manufacturing the improved composition I combine by heat in a suitable
vessel mineral wax or paraffin wax, wood tar, shellac and asbestos or other suitablé
dry fibrous substance, in or about the following proportions, videlicet, about one
part by weight of wax, twenty four parts of wood tar, and thirty two parts each
of shellac and asbestos or other suitable dry fibrous substance. The above
proportions are those which I have found to answer well for a soft compound
suitable for such uses as those for which gutta percha has generally been
employed.
Where a harder compound is required the proportion of wood tar is diminished.
For an extra hard compound the wax may be omitted and about twenty four
parts of ground slate or silicate may be added and the proportion of asbestos
diminished.
In manufacturing the compounds I combine the above named ingredients
together by heat and continued stirring until they form a thick paste and the
compound can then be poured into moulds of the required shape. 'Or the herein.
before described compounds when in a hot pasty condition may be spread out on a
plate of iron, stone or other suitable material by rollers or otherwise to the

page_text: requisite thickness and width and when cool can be cut, sawn, turned in a lathe or
attached by heat to any other material and pressed thereon if required for taking
impressions and the like.
If required in a very dense condition the compounds may be subjected to
pressure.
The compounds are not affected by water or by the atmosphere or by diluted
sulphuric acid up to one part of sulphuric acid to six parts of water; will not soften
at 130° Fahrenheit and are not sticky to the touch and cuttings and waste pieces
can be remelted for reuse.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Murdoch Mackay in the Great Seal Patent Office on the 4th January
1883.
MURDOCH MACKAY of Mansion Street in the county of Surrey Chemist
" AN IMPROVED MANUFACTURE OF INSULATING COMPOUNDS, APPLICABLE ALSO TO
OTHER PURPOSES
"
This invention relates to the manufacture of improved compounds or compositions
for electric insulation also applicable for forming moulds for electro deposition for
electro plating and for copying wood cuts in copper by the electro process also for
copying set up type, engravings and the like.
In manufacturing the improved composition I combine by heat at a temperature
of from about one hundred degrees Fahrenheit to about two hundred and twelve
degrees Fahrenheit in a suitable vessel mineral wax such as paraffin wax or
ozokerit wax, vegetable tar (commonly known as wood tar) shellac and asbestos or
other suitable dry fibrous substance, in or about the following proportions, videlicet,
about one part by weight of wax, twenty four parts of wood tar and thirty two
parts each of shellac and asbestos or other suitable dry fibrous substance such as
wood, flax, cotton or paper in a dry powdered state. The above proportions are
those which I have found to answer well for a soft compound suitable for such
uses as those for which gutta percha and ebonite have generally been employed.
Where a harder compound is required the proportion of wood tar is diminished.
For an extra hard compound the wax may be omitted and about twenty four
parts of ground slate or silica or clay free from iron may be added and the
proportion of asbestos diminished.
In manufacturing the compounds I combine the above named ingredients
together by heat and continued stirring until they form a thick paste and the
compound can then be pressed into moulds of the required shape. Or the herein-
before described compounds when in a hot pasty condition may be spread out on a
plate of iron, stone or other suitable material by rollers or otherwise to the
requisite thickness and width. When cool the compounds can be cut, sawn, turned
in a lathe or attached by heat to any other material and pressed thereon if
required for taking impressions and the like.

page_text: If required in a very dense condition the compounds should be subjected to
considerable pressure in the moulds.
The compounds are not affected by water or by the atmosphere or by diluted
sulphuric acid up to one part of sulphuric acid to six parts of water; will not
soften at one hundred and thirty degrees Fahrenheit and are not sticky to the
touch and cuttings and waste pieces can be remelted for reuse.
Having thus described my invention and the manner of performing the same
What I claim is :-
The improved insulating compounds described consisting of a mixture of mineral
wax (such as paraffin wax or ozokerit wax) vegetable tar commonly known as
wood tar, shellac and asbestos or other suitable dry fibrous substance such as wood, ·
flax, cotton or paper in a dry powdered state in substantially the proportions
named, ground slate or silica or clay free from iron being sometimes employed in
place of wax, substantially as and for the purposes described.
In Witness whereof I the said Murdoch Mackay have hereto set my hand
and seal this third day of January in the year of our Lord one thousand
eight hundred and eighty three
Witness.
G F REDFERN
Patent Agent
4 South St
Finsbury
London.
MURDOCH MACKAY (L.&.)