RESEARCH & DEVELOPMENT ESTABLISHMENT.
British-American Tobacco Co.. Ltd.. Southampton.
D.3.F.HOBSOR,ESQ.
1) tip,
DGF/FB/46B PT11V 23rd January, 1959.
Mr.L. Laporte,
Imperial Tobacco Co. of Canada Ltd.,
P.O. Box 6500,
Montreal,
CANADA.
Dear Leo,
I understand that you are interested in the
studies we have
mde of the use of tobacco as a filter and in the
possible use of
tobacco flour as an additive to other types of
filters.
Our initial interest in this was aroused by
c:)nsidcration
of ways In which some taste qualities might be
restored to smoke
after, or during# passage through a conventional
filter. it
occurred to us, early on~, that a definite
toba,_-co flavour can be
given to air when it is drawn through an unlighted
cigarette.
Moreover, we knew that the tobacco butt of a
cigarette e,-crtc,l a
filtration actionj we understand, in the early
days of filter-
tipped cigarettes, that the filter-tips were often
less efficient
than the tobacco they replaced.
We therefore decided to investigate the fIltration
efficiency
of tobacco plugs wherein the tobacco was much more
finely shradded
than in normal cigarettes. Our initial
investigations, which were
made on tobacco plugs made from Players Medium
blend but cut at 80,
150 and 200 c.p.i. and at two different veights,
20 and 22 cigs./oz.,
.were recorded in Report RD32, a copy of which.I
enclose. You will
appreciate that this report was written before we
had got our
methodology straight for filter investigations.
!-'e should tackle
the problem differently nowadays . The results
were sufficiently
encouraging to warrant further work. You will see
that a 13 mm.
plug out from a tobacco rod (78 z 25 cm.) mad6 at
20 rods/oz. from
a blend out at 200 a.p.i. has 'a filtration
efficiency of rb-)ut 30"-
Compared with the smoke passing through an Estron
filter of this
efficiency, the tobacco filter gave smoke judged
to be of griater
tobacco character, especially for the first few
puffs.
At this stage, it was impressed upon us that these
iindings
could have considerable inportance, especially for
certain
territories where filter rods were imported and
therefore relatively
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BATCo document for Province of British Columbia 29
October 1999


RESEARCH & DEVELOPMENT ESTABLISHMENT,
Blicish-Ameriran Tobacco Co., Ltd.. Southampton.
Mr.L.LaDorts
22.1.59
expensive, but where native grown tobacco was
cheap. We were
directed to see whether the idea was patentable
and produced a
number of alternative drafts for patent
specification. These
were submitted to the London Patent Agents
retained by the Company
who gave their opinion that tobacco 1per so could
not be patented
is a filter whatever fineness of cut was employed,
since it was a
logical extension of what was an old idea. An
invention would
revalt if there was sow umexpeetedly advantageous
critical range
of fineness, but we could not produce my reason.
to expect this.
Despite this conclusion, it was felt that we
should pursue
the matter, with the Imowledge that if we could
not patent the
idea, then nor could az7one else! We therefore had
cigarette rod
manufactured fram lamina and CRS separately, cut
this time at 200,
220 and 500 (nominal) c.p.i. and again made both
at 20 and 22
rods/oz. The filtration efficiencies of these rods
have been
investigated somewhat sporadically in the past six
months. The
results are now reported in RIY74, and I enclose a
copy for you.
You will see that our earlier conclusion that
tobacco is as gool an
or better than cellulose acetate, when compared on
a basis of equal
draw resistance, is justified. The retention
coefficient is
somewhat higher than that for cellulose acetate
under the smoking
conditions employed.
Meanwhile the possibility of patenting the use of
CPS as a
filter medium wqs investigated, but was found to
be protected by
British Patent 781960 (to Reynolds Tobacco Co.)
which moreover
covers a paper made partly or wholly from stem
material. This
would seem to cover the use of FCL in a smokable
form.
. A third possibility which was investigated with
the Patent
Agents, was the idea of using powdered tobacco as
an additive to
conventional filter material, with or vithout
additional tobacco
extract as an iVregnation. We had a meeting with
tho Patent
Agents at which it became clear that the use of
other fibrous
additives, esg. Voodfly, starch,of--cellulose etc.
did not preclude
the use of tobacco flour, and that although
tobacco extract alone
was covered by British Patent 708,604, this did
not extend to the
use of a combination of tobacco flour and tobacco
extract. The fact
that the use of additives conferred the additional
advantage of
enhanced flavour was not, in itself, patentable.
Further study of
those patents liste' below in which additives were
used in filters,
confirmed that tobacco flour was, as yet,
unpatented. The patents
studied weres-
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BATCO document for Province of BritiSh Columbia 29
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RESEARCH & DEVELOPMENT ESTABLISHMENT.
British-American Tobacco Co.. Ltd., Southampton.
-3-
W.L Lai3orte
22.1.59
'U. S.Patent 2:774,680 E.J.Hackney at al -
Assignors to
2 778,403 Liggett & Yqeris Tobacco Co.
2#805,671
2,794p239 Crawford & Stevens - Assignors
2,794,4W to Eastman.Kodak.
British Patent 773,701 Eastman Kodak.
Canadian Patent 539,0,42 Knudson - Assignor to
P.Lorrilard & Co.
Swiss Patent 3229609 PIorillard & H.&
V.Specialtics Co.Inc.
Accordingly notes for a draft Provisional
Specification were
drawn up, based on what limited experimentation we
had already done,
and these were submitted to the Patent Agents who
drew up and filed
Provisional Specification 25564/58 - filed on 8th
August, 1958.
The Agents subsequently assured us that there isas
no anti-
cipation of the proposals covered in the
application. There, through
force of other work, we were obliged to leave the
matter last August.
We have until August 1959 to complete experirents
in order to file a
complete Specification. We are s-:)mevftt
handicapped in the absence
here of a machine for producing filter tips from
Estron tow on a
production basis, so that so far we have been
unable to stud:7 the use
of tobacco flour as an additive to cellulose
acetate.
With kind regards.
Yours sincerely,
Eno.
C.C. D.S.F.Hobson,Esq.
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BATCO document for Province of British Columbia 29
October 1999