U.S. patent number 3,584,630 [Application Number 04/852,983] was granted by the patent office on 1971-06-15 for tobacco product having low nicotine content associated with a release agent having nicotine weakly absorbed thereon.
This patent grant is currently assigned to Philip Morris Incorporated. Invention is credited to George Esler Inskeep.
United States Patent |
3,584,630 |
Inskeep |
June 15, 1971 |
**Please see images for:
( Certificate of Correction ) ** |
TOBACCO PRODUCT HAVING LOW NICOTINE CONTENT ASSOCIATED WITH A
RELEASE AGENT HAVING NICOTINE WEAKLY ABSORBED THEREON
Abstract
This disclosure relates to a tobacco product containing a
nicotine-releasing agent and to a method for releasing a controlled
amount of nicotine into tobacco smoke. The nicotine-releasing agent
comprises a finely divided, weak absorbent of gas furnace or
channel carbon black, the said carbon black having on its surface
weakly adsorbed per part of weak adsorbent. The nicotine is
released from the weak adsorbent during smoking to bring the
nicotine content in the smoke generated by a low nicotine tobacco
with which it is associated, to a total level of 0.1--3.0 mg.
Inventors: |
Inskeep; George Esler
(Richmond, VA) |
Assignee: |
Philip Morris Incorporated (New
York, NY)
|
Family
ID: |
25314716 |
Appl.
No.: |
04/852,983 |
Filed: |
August 20, 1969 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
|
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603419 |
Dec 21, 1966 |
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Current U.S.
Class: |
131/335 |
Current CPC
Class: |
A24B
15/281 (20130101); A24D 3/14 (20130101); A24B
15/282 (20130101) |
Current International
Class: |
A24D
3/14 (20060101); A24B 15/28 (20060101); A24D
3/00 (20060101); A24B 15/00 (20060101); A24d
001/06 () |
Field of
Search: |
;131/9,10,10.5,10.7,261--269,23,10.9 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
Primary Examiner: Rein; Melvin D.
Parent Case Text
This application is a continuation of Ser. No. 603,419 filed Dec.
21, 1966, now abandoned.
Claims
Having described my invention, what I claim as new and desire to
secure by Letters Patent is:
1. A tobacco product comprising a tobacco section and a filter
section, said filter section including a weak adsorbent agent of
limited adsorptive ability therein selected from the group
consisting of gas furnace or channel carbon black, said carbon
black adsorbent having a specific surface area greater than 1
square meter per gram, and a charge of nicotine weakly adsorbed on
the surface said carbon black, the tobacco of the tobacco section
being of a low nicotine content, the smoke from which has its
nicotine content increased to a total value of 0.1--3.0 mg. of
nicotine upon release of the nicotine from the weak carbon black
adsorbent during smoking.
Description
This invention relates to a tobacco product containing a
nicotine-releasing agent and to a method for releasing a controlled
amount of nicotine into tobacco smoke. More particularly, the
invention relates to tobacco products containing an agent for
releasing nicotine into tobacco smoke which agent permits storage
of tobacco products containing said agent for prolonged periods of
time, without substantial loss of the nicotine associated with said
agent. The agent provides for the release of nicotine in controlled
amounts, when tobacco smoke is passed in contact with the
nicotine-containing agent.
It has long been known in the tobacco industry that in order to
provide a satisfying smoke, it is desirable to maintain the
nicotine content of tobacco products at a uniform level. However,
it is difficult to accomplish this result since the nicotine
content of tobacco varies widely, depending on the type of tobacco
and the conditions under which the tobacco is grown.
Among the factors affecting the nicotine content of any variety of
tobacco are the conditions which exist during the growth of the
tobacco, for example, the moisture conditions, the type of soil,
the fertilizers that are employed, the number of tobacco plants per
acre and the care which is given to the plants during their growth.
The nicotine content also varies widely, depending on the variety
of tobacco. Many of the newer varieties of tobacco plants yield
tobacco which is low in nicotine. Furthermore, methods of preparing
tobacco products frequently remove some or all of the nicotine that
is naturally present in the tobacco. In addition, modern technology
has made it possible to utilize portions of the tobacco plant other
than the leaf for smoking and some of these portions, such as the
petioles, are low in nicotine content.
Maintaining the nicotine content at a sufficiently high level to
provide the desired physiological activity, taste, and odor which
this material imparts to the smoke, without raising the nicotine
content to an undesirably high level, can thus be seen to be a
significant problem in the tobacco art. The addition of nicotine to
tobacco in such a way that it remains inert and stable in the
product and yet is released in a controlled amount into the smoke
aerosol when the tobacco is pyrolyzed, is a result which is greatly
desirable.
The present invention provides a solution to this longstanding
problem and results in accurate control of the nicotine which is
released in tobacco smoke. By employing the nicotine-releasing
agents and methods of the present invention, it is possible to
incorporate exact amounts of nicotine in a tobacco composition,
which will remain constant over extended periods of time and which
will ultimately yield a smoke containing a controlled amount of
nicotine.
The present invention may also be used to incorporate flavorants
into tobacco smoke.
Often flavor or flavors which are incorporated in tobacco, are lost
or altered during subsequent manufacturing steps, or storage. It
can also be difficult to control the amount of flavor released
during the smoking of a tobacco product to insure uniformity of
tobacco flavor during the entire smoking process.
While many efforts have been made to introduce flavors into tobacco
smoke, no completely satisfactory method has been found. For
example, a method has been employed, whereby flavoring gases have
been incorporated into the tobacco in the form of stable esters
which decompose upon pyrolysis. Such a method, however, is only
useful for certain types of flavorants and also may result in the
incorporation into the smoke of breakdown products of the pyrolysis
of the esters.
The increasingly widespread use of filter tip cigarettes, has
further complicated the efforts to solve the above-mentioned
longstanding problems. The various filters are efficient absorbers
which extract from the smoke nicotine, as well as many other flavor
components, and thus can deprive the smoke of the qualities which
are desired by smokers.
However, while the present invention can be employed to incorporate
flavors into tobacco smoke, it is particularly useful for the
maintenance of the proper amount of nicotine in tobacco smoke.
Thus, the discussion which follows and the examples are directed
essentially to the use of a nicotine-containing agent in a tobacco
product.
With regard to the above-discussed problems of maintaining the
nicotine content of tobacco products to the proper level to provide
the desired qualities in tobacco smoke, previous efforts have been
made to add nicotine to tobacco products wherein the nicotine level
in the tobacco was undesirably low.
Such efforts have included adding nicotine per se to the tobacco.
However, it has not been found feasible to add nicotine per se to
tobacco products. For one thing, the nicotine can be absorbed
through intact skin and is, thus, difficult and hazardous to handle
in processing operations. In addition, free nicotine is a very
volatile material and will volatilize readily at room conditions.
Therefore, the addition of nicotine into a tobacco product as the
free material could readily result in a substantial loss of the
nicotine during storage of the tobacco product. Even though the
nicotine content of tobacco products could, by the addition of
nicotine content of tobacco products could, by the addition of
nicotine under conditions involving considerable effort, be made
initially uniform, the volatization losses attending storage of the
product would not provide smoke containing a uniform amount of
nicotine.
In U.S. Pat. No. 3,109,436, a solution to the problem of adding
nicotine to tobacco products has been set forth. In that patent,
nicotine-ion exchange resins are incorporated in the tobacco. The
nicotine-ion exchange resins decompose upon smoking of the tobacco
to result in incorporation of the nicotine in the smoke. The
present invention provides even greater improvements than those
obtained in accordance with that invention, however, in that there
are no ion exchange breakdown products introduced into the
smoke.
In U.S. Pat. No. 3,280,823, a further solution to the problem has
been provided. In that patent, the nicotine-ion exchange resins are
incorporated in filters for tobacco smoke. The invention involved
in that patent provides an improvement over the invention set forth
in U.S. Pat. No. 3,109,436, in that the use of the ion exchange
resin in the filter eliminates the incorporation in the tobacco
smoke of ion exchange breakdown products. The present invention
provides even greater improvements than those obtained in
accordance with the invention set forth in U.S. Pat. No.
3,280,823.
When the present agents are incorporated in tobacco, they provide
an efficient release of the nicotine into the tobacco smoke and do
not involve incorporation into the tobacco smoke of any undesirable
breakdown products. Thus, the present invention overcomes the
disadvantages of the method described in U.S. Pat. No. 3,109,436.
When the present agents are incorporated in the filter for tobacco
smoke, superior results to those obtained by following the
teachings of U.S. Pat. No. 3,280,823 are obtained, in that they
provide more efficient transfer of nicotine from the agent to the
tobacco smoke. They also provide a more economical method of
incorporating nicotine into a tobacco product, since they are more
easily prepared and are less expensive than the nicotine-ion
exchange resins.
It is an object of the invention to provide a method for treating
tobacco smoke which overcomes the above-mentioned disadvantages of
the prior art.
It is another object of the invention to provide an agent for the
treatment of tobacco smoke whereby nicotine is easily released
thereinto in controlled amounts.
In accordance with the present invention, an agent for
incorporation in a tobacco product is provided which comprises a
finely divided weak absorbent having nicotine disposed on its
surfaces.
As used herein the term "weak adsorbents" is intended to include
"primary weak adsorbents" and "secondary weak adsorbents" and
includes adsorbents composed of particles having the following
characteristics:
1. The surface of the particles is principally formed by the
exterior of the particles, in contrast to the surfaces formed by
the pores and fissures, if any, of the particles or the particles
are hydrophilic in nature and, thus, hold moisture in a manner
whereby the nicotine is readily displaceable by the moisture
present in tobacco smoke coming in contact therewith;
2. The particles do not tend to form chemical bonds with nicotine;
and
3. The particles absorb substantially no nicotine.
The term "weak adsorbents" if intended to include materials having
a specific surface greater than one square meter per gram and the
"primary weak adsorbents" and "secondary weak adsorbents" relate,
respectively, to:
a. adsorbents, the surface of which is principally formed by the
exterior of the particles and
b. particles which are hydrophilic in nature, as set forth in (1)
above and possessing the other properties which are set forth
above.
The weak adsorbent, as it is employed in accordance with the
present invention, holds the nicotine on its surface during storage
of the tobacco product and releases the nicotine into the tobacco
smoke which forms when the tobacco product is smoked.
Tobacco products into which the present agent may be incorporated
include filter tip and nonfilter cigarettes, cigars and cigarillos,
as well as pipe tobacco, pipe filters and other products through
which tobacco smoke passes on the way to the smoker's mouth. The
agent can be incorporated directly in the tobacco or can be
incorporated in the filter for tobacco smoke. Preferably, the agent
is employed in a filter, since this method removes any possibility
of decomposition of the nicotine during combustion of the tobacco
and since the method provides for the most accurate control of the
amount of nicotine which is incorporated in the smoke.
In accordance with the present invention, it has been found that
not all adsorbent materials will provide a base for nicotine, which
base will hold the nicotine during storage but from which nicotine
can be easily removed into a passing smoke stream. It has been
found that the adsorbent, to be effective in accordance with this
invention should be a finely divided, weak adsorbent, of limited
adsorptive ability. For example the weak adsorbent may be a primary
weak adsorbent, such as carbon black, lampblack, gas furnace black,
channel black bentonite, titania, calcium or magnesium silicate,
hydrated alumina, and the like. Other primary weak adsorbents which
may be employed include kaolin, montmorillonite, attapulgite, and
finely divided polyacrylonitrile, microcrystalline cellulose,
polyvinylidene chloride and similar nonabsorbent polymers.
Somewhat stronger adsorbents than those set forth above may also be
used. However, when such adsorbents are employed, they should have
a high affinity for water, and can be categorized as hydrophilic
adsorbents. Such hydrophilic adsorbents are herein designed as
"secondary weak adsorbents" and include materials such as silica
gel, alumina, aluminosilicates, activated alumina, large pore
zeolites and the like. The high moisture content of tobacco smoke
causes the hydrophilic adsorbents to release the nicotine or other
tobacco additive deposited on their surface, while they tend to
adsorb, due to their affinity to water, the moisture content of the
smoke. The proportion of smoke moisture so adsorbed, however, is
small.
In accordance with a preferred embodiment of the invention, the
tobacco treating agent forms a part of a filter tip, or a portion
of a filter tip, for a smoking article such as a cigarette. The
nicotine is deposited on the finely divided particles of the mild
adsorbent or hydrophilic adsorbent carrier which has the capability
of holding the nicotine in readiness to be dislodged by contact
with the smoke. The coated carrier can be placed into a chamber of
the filter tip, but preferably, the carrier, with its additive
coating, is applied onto a tow or web filter substrate, to be less
compact and more readily permit the passage of smoke therethrough.
This latter combination can form part of the filter tip.
The nicotine can be deposited on to the surface of the adsorbent
carrier of the invention by any method which permits relatively
uniform distribution of the nicotine on the surface of the carrier.
Well-known methods for this purpose include impregnation of the
carrier by soaking it in a nicotine solution, spraying it with a
nicotine solution, adsorption on the carrier of nicotine from a
nicotine solution, condensation of nicotine from vapor phase on the
carrier, and the like. For treating the weak adsorbents such as
carbon black, the nicotine solution can be added to the adsorbent
and the resulting mixture stirred or tumbled in order to thoroughly
blend the same. In the case of weak adsorbents of the hydrophilic
adsorbent-type, preferably these materials are soaked with a
solution of nicotine and a relatively nonpolar solvent, followed by
filtration of the mixture and evaporation of any solvent retained
on the nicotine-containing adsorbent.
The proportion of nicotine to dry adsorbent will generally be
between 1:20 and 1:1, on a weight basis, respectively, and will
preferably be between 1:10 and 1:2, respectively.
The amount of nicotine (in nicotine-adsorbent form) added to a
filter, on a cigarette basis, may be from 2.0 to 35.0 milligrams
per cigarette and preferably from 4.0 to 12.0 milligrams per
cigarette, depending on the amount of nicotine in the tobacco. Only
sufficient nicotine should be added to the tobacco product to
result in a nicotine content in the tobacco smoke approximating
that of a conventional tobacco product.
The amount of nicotine-adsorbent that is added to the tobacco will
vary depending upon the nicotine content originally present in the
tobacco and upon the nicotine content desired in the smoke.
Generally, the nicotine content of the tobacco is importantly to a
level whereby there is 0.1--3.0 mg. of nicotine in the smoke per
cigarette.
One method of determining how much of a particular nicotine
adsorbent to add to a particular tobacco product is to analyze the
smoke from the tobacco product in which the nicotine-adsorbent
agent is incorporated, which can be done by conventional methods,
such as is described in the "Journal of the Association of Official
Agricultural Chemists" (vol. 42) (Nov. 2, 1959) on pages 424--429.
In accordance with this method, an aqueous solution of smoke
particulate phase is steam distilled under appropriate conditions;
this is followed by spectrophotometric examination of the resulting
distillate in the ultraviolet spectral region.
The directions for the details of this procedure include the
following:
Collect the smoke particulate phase from 10 successive cigarettes,
using a standard robot smoking procedure (35 ml. puff volume taken
over a 2 second interval, once per minute) upon a glass wool plug
or an equivalent collection medium suitable for separation of 0.1
.mu. particles and larger from a gas particulate phase mixture.
Strip the nicotine alkaloids from the collection medium with four
10 ml. portions of 0.05 N HC1. Combine the separate eluates and
dilute to exactly 50 ml. with 0.05 N HC1. Transfer a 10 ml. aliquot
of this solution to the port of the distillation unit. Distill
approximately 100 ml., and discard. Make the sample in the unit
alkaline by adding a size 00 capsule of NaC1 and a size 00 capsule
of Na0 H, in that order. Repeat the distillation and collect a
second 100 ml. portion, as follows: distill approximately 98 ml.
into a 100 ml. volumetric flask to which 5 ml. 3 N H.sub.2 S0.sub.4
has previously been added. Dilute the distillate exactly to mark
with distilled water, mix well, and examine spectrophotometrically
between 230 and 300 .mu.. Correct the absorbance of the unknown
solution at approximately 260 .mu. by a baseline selected on the
basis of the curve. Draw a line from the lowest point on both sides
of the maximum absorbance. The difference between the baseline and
peak at the wavelength of the peak is taken as the absorbance of
the sample. Compare this corrected absorbance to the absorbance of
the standard nicotine solution corrected in the same manner, and
calculate the nicotine content of the sample directly from this
comparison, using standard spectrophotometric technique.
Mg. nicotine alkaloid =(A/A' )X(mg. known per ml. X dilution
factor/no. cigarettes in sample); where A is corrected absorbance
of unknown, and A' is corrected absorbance of known.
The nicotine-adsorbent content for the tobacco can, by making tests
as set forth above, be adjusted to bring the nicotine in the smoke
to within the range which is desired.
The invention, accordingly, comprises the several steps and the
relation of one or more of such steps with respect to each of the
others, and the article possessing the features, properties, and
the relation of elements, which are exemplified in the following
detailed disclosure.
Example 1
A mixture of 1 gram nicotine sold by the Eastman Chemical Company,
under the designation "White Label" was blended by manual stirring
with 5 grams of gas furnace carbon black sold by the Cabot
Corporation under the trade name "Sterling R." The mixture was set
aside overnight and was then weighed. The weight loss was found to
be 0.3 percent. A 0.6 gram portion of this mixture was spread
evenly over a thin cotton web. The coated web was rolled
transversely and set into a hollow paper tubing having an inside
diameter of 7.8 mm. and the resulting rod was cut into 1 cm.
lengths. The sections, corresponding to the diameter of a
conventional cigarette, had a resistance-to-draw of 1.5--2 inches
of water, as determined by a "Magnehelic" gauge connected to the
line in which the filter sections were inserted and through which
air was drawn at the rate of 600 cc./minute.
The sections were found to contain 0.054 grams of the mixture.
Cigarettes were prepared, with the sections prepared in accordance
with the foregoing, attached to the tobacco rod, followed by a 5
mm. long section of a conventional cellulose acetate backup filter,
with a resistance-to-draw, as determined above, of 1.2 inch of
water. The smoke of the cigarettes prepared in accordance with this
example was found by the method describe above to contain 1.61 mg.
nicotine per cigarette. Control cigarettes made with conventional
filters, but without the implement of the invention, having the
same resistance-to-draw, delivered only 1.14 mg. nicotine.
Example 2
A solution of 2 grams nicotine of the type used in Example 1, in 20
ml. n-hexane was applied to 2 grams of dry silica gel sold by the
Davison Chemical Division of W. R. Grace & Company under the
trade designation "Grade 62," and having a particle size of
60.times. 200 mesh. The solution was applied to the silica gel
carrier by manual stirring. After 3 hours resting, the solid was
separated by filtration, and air-dried for 2 hours. The weight of
the silica gel increased by 26.5 percent and was found, by the
method described above to contain 18.8 percent total alkaloids,
which represented 23.1 percent of the weight of the silica gel.
The nicotine-coated silica gel was spread evenly over a thin cotton
web which was rolled to fit into paper tubing of cigarette
diameter. The resulting rod was cut into 1 cm. lengths, each
containing about 31 mg. of the nicotine-coated silica of which 5.9
mg. was nicotine. The resistance-to-draw of the filter plugs was
found to be 2.1--2.3 inch of water. The plugs were attached to the
ends of cigarette tobacco rods, making thereby the plugs into
cigarette filter tips, the outer end of the tip then was backed up
by 5 mm. lengths of conventional cellulose acetate filters having a
resistance-to-draw of 1.2 inch of water. The analysis of the smoke
by the method described above showed 1.47 mg. nicotine, as compared
to the smoke obtained for control cigarettes identically made, but
without the silica-nicotine and with a cellulose acetate filter tip
of slightly lower resistance-to-draw, as control, the smoke of
which contained only 1.14 mg. nicotine.
Example 3
A cigarette equipped with auger high-efficiency filter containing
in one section 83 mg. of an activated coconut charcoal delivered
0.58 mg. of nicotine in the smoke. When the same cigarettes had
nicotine applied to the charcoal in quantities of 9, 15 and 25 mg.,
the increase in nicotine delivery was 0.16, 0.29 and 0.90 mg.,
respectively. These represent 1.8, 1.9 and 3.6 percent of the added
nicotine, a decidedly lower proportion than that shown in Examples
1 and 2, even for the uneconomically high 25 mg. level. This
example illustrates the disadvantage of using a strong but
nonhydrophilic adsorbent as a carrier for nicotine.
Example 4
To 5.0 g. of "Monarch" 81 channel carbon black (Cabot Corp.) was
added 1.0 g. of nicotine (Eastman Chemical Co., white label) and
the mixture was blended by hand. This mixture was blended with the
tobacco filler of handmade cigarettes at the rate of 30 mg. per
cigarette. Cigarettes were also made up from the same filler
without the added nicotine-carbon, both rods having the same weight
and resistance-to-draw. The 65 mm. rods were attached to 20 mm.
filters of cellulose acetate having high efficiency of particulate
removal. The experimental cigarettes delivered an average of 1.4
mg. of nicotine per cigarette; those without the additive delivered
0.78 mg. in the smoke.
Example 5
Nicotine as a 10 percent by weight solution in n-hexane was applied
to activated alumina.
After standing overnight, the alumina was separated by filtration
and air-dried and was found to contain 14.5 percent of nicotine,
based on total weight. This material was spread evenly on a thin
cotton web which was then rolled and fed into a tube of stiff paper
having the diameter of a cigarette; the weight of alumina-nicotine
was 65 mg. per cm. of length (or 9.5 mg. nicotine). The filter tube
was cut into 1-cm. sections which were attached to cigarette rods
together with a 1-cm. backup filter of cellulose acetate. Filters
2-cm. long consisting only of cellulose acetate and having total
resistance like the preceding were attached to the same type of
cigarette rods to provide controls. Samples with additive delivered
1.6 mg. nicotine to the smoke; the controls delivered 1.1 mg.
It can thus be seen that the objects set forth, and those made
apparent from the preceding description, are effectively obtained,
and since certain changes may be made in carrying out the above
process and in the article set forth without departing from the
scope of the invention, it is intended that all matter contained in
the above description shall be interpreted as illustrative and not
in a limiting sense.
* * * * *