Note: Descriptions are shown in the official language in which they were submitted.
1047241
This invention concerns improvements relating to non-tobacco
loking materials, that is smoking materials which contain no
tobacco other than a possible content of tobacco extract. The
materials may be used alone as tobacco substitutes, but are prefer-
ably used in ad~ixture with tobacco or reconstituted tobacco or
other smoking materials, It is an object of this invention to
provide advantageous non-tobacco smoking materials of low density,
and a method for their production.
In accordance with the invention, a non-tobacco smoking mate-
rial comprises a binder consisting wholly or in at least a propor-
tion of 10% by weight of thermo-gelling substituted cellulose having
a degree of substitution of ~t least 1.5 methoxyl groups per an-
hydroglucose unit, and an inert water-insoluble inorganic diluent,
which material has had its density reduced by the entrainment and
disper~ion of air therein to provide a foam material comprising
closed air cells. The use of this particular binder permits the
production of a smoking material whose density has been reduced by
the entrainment and dispersion of air without recourse to foaming
by the use of a surfactant or a blowing agent in the form of a
vapour-releasing substance such as bakin~ powder or a dissolved or
dispersed volatile solvent such as heptane. The material will not
contain chemical residues of surfactant or vapour-releasing sub-
stances. Such residues would normally be considered to have an un-
~- desirable effect on the smoke properties.
The s~oking material may also comprise a content of caramel
and/or tobacco extract. It may further contain a humectant, such
as glycerol or sorbitol or other material well known in the art.
` The physical and smoke properties of materials whose density
has been reduced by means of entrainment and dispersion of air are
different from those of materials whose density has not been so re-
.
~04724~
duced and from those of a mere mixture of binder and filler.
By a thermo-gelling substituted cellulose is meant one which
forms a thermo-gelling solution in water, that is a solution whose
viscosity increases sharply with increasing temperature in a partic-
ular temperature range dependant on the substance. The thermo-
gelling substituted cellulose employed may be a methyl cellulose and/
or an additionally substituted methyl cellulose having at least the
aforesaid degree of substitution. Such methyl cellulose may be used
; in a & ixture either with a methyl cellulose of lower methQxy content
or with a non thermo-gelling substituted cellulose such as sodium
i; .
carboxymethyl cellulose. The purpose of the invention, namely the
production of a non-tobacco smoking material of low density without
using blowing agents, cannot be satisfied in such admixtures unless
~ at least one tenth of the binder consists of thermo-gelling methyl
;, cellulose or additionally substituted methyl cellulose of at least
the aforesaid methyoxy content. By additionally substituted methyl
,~ cellulose is meant a methyl cellulose containing a proportion of
- carboxymethyl or other like substituents. A sufficiently high
methoxy content for the said purpose of the invention will generally
~' 20 be a degree of substitution referred to as "high" by manufacturers
of such products, this degree of substitution usually being in the
range of 1.5 bo 2.4 methoxy units per anhydroglucose unit. Because
,:,
of the nature of these products, however, which are intrinsically
variable, the exact degree of substitution is not always specified
;,-.,
by manufacturers.
Also in accordance with the invention, a method of producing
such a non-tobacco smoking material comprises mixing a binder con-
sisting wholly or in at least a proportion of l~h by weight of
thermo-gelling substituted cellulose having a degree of substitution
of at least 1.5 methoxyl groups per anhydroglucose unit with an
~ ` -2-
10~7241`
inert water-insoluble inorganic diluent and reducing the density
c the resulting material by entraining and dispersing air in the
mixture to provide a foam material comprising closed air cells.
Suitably, a planetary mixer is used to disperse and dissolve
the constituents in water prior to the bringing of the material
to a state for suitable use in a smoking mixture. This type of
mixer itself whips a proportion of air into the slurry being
prepared. However, an acceptably uniform product containing air
bubbles, preferably small closed bubbles, in large numbers
cannot be so obtained. It......
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1047~41
is necessary and indeed advantageous to utilise a high-shear
mixer, for example the E.T. Oakes continuous automatic mixer,
which has provision for the introduction of a controlled
further quantity of air, over and above such air as may be
introduced by the action of the planetary mixer, as well as
provision for circulating temperature-controlled hot water
through the jacket of the mixer head. Advantageously, the
mixture is brought to a temperature in the range of 35 to
60C. The effect of the high shear mixer is principally
a reduction in air-bubble size. The maximum bubble size
should be less than the thickness, and preferably less than
half the thickness, of the sheet material to be produced,
so that, substantially, the bubbles do ~ot break the surface
; of the sheet. By the aforesaid method, a uniform foam
material with closed cells can be reliably reproduced with-
out the use of additional foaming, blowing or like agents
and without the necessity for close observance of conditions
involved in foaming or blowing with the used of such agents.
The inert inorganic diluent or filler is advantage-
ously calcium carbonate (chalk or whiting), but other compounds
such as calcium sulphate (gypsum), calcium phosphate, alum-
` inium trihydrate, aluminates or the like may be used, provided
` they are insoluble in water.
The composition may comprise also a content of caramel
; or tobacco extract. Caramel may serve as a complete or partial
replacement for tobacco extract known as a constituent of
! tobacco substitutes. The composition may further comprise
a content of humectant such as glycerol. The composition
need contain no other constituents.
Suitable proportions of the constituents by weight are,
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l~i'i'241
for example~
~` Binder, 5% to 15%, in which the substituted cellulose ofthe aforesaid high methoxy content should be
from 10% to I00% of the binder. Preferably
the binder content is from 7% to 13%.
Caramel and/or tobacco extract, 2% to 20%, but preferably
8% to 16%.
Inert inor~anic diluent, 60% to 90%, but preferably 75%
to 85%.
Humectant, 1% to 10%, but preferably 2% to 6%.
If such a composition is used shredded in mixture with
, cut tobacco and/or reconstituted tobacco, the proportion of
the composition in the mixture may be within the range of
, 1% to 99%, but usually in the range of 5% to 75%, by weight.
The following Examples illustrate how the invention
may be carried into effect.
Example 1
O.5 parts of B.P. grade glycerol were added to 51
parts of water in the bowl of a Hobart planetary mixer having
. 20 a gate-type beater blade, followed by the addition of 1.6
parts of a commercially available sodium carboxymethyl methyl
cellulose (Grade C7501, Henkel Chemicals Ltd., having a
viscosity 2,300 cps, approximately, in 2% solution in water
at 20C according to the method of Brookfield, and an average
methoxyl degree of substitution of 1.67, together with a low,
unspecified, degree of substitution of sodium carboxymethyl
groups per anhydroglucose unit). The mixture was stirred
for one hour before the addition of 15.2 parts of commercial
whiting (high purity, 90% smaller than BS 200 mesh). The
slurry was stirred for a further two hours in the same mixer
.".
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11)~7241
and the resultant slurry was then fed through an Oakes high- -
shear continuous automatic mixer with controllable air
injection and provision for circulating temperature-controlled
hot water through the jacket of the mixer head. The rotor
speed of the Oakes mixer and the temperature of the circu-
lated water were adjusted so that the aerated slurry was
delivered at a temperature of 42C - 48C to a gate coater
and was cast as a sheet on an endless stainless steel band
passing through a series of drying chambers, as commonly
used in the manufacture of tobacco-sheet products, the air
temperature ranging from 80C -to 110C with provision for
underband steam heating. The minimum rotor speed of the
Oakes mixer to give suitable small air bubbles was 250 rpm.
At the maximum air feed rate to the Oakes mixer at which a
coherent product could be formed in this Example the sheet
produced had a specific gravity of 0. 25, and specific
gravities increasing to 0. 75 were produced as the air-
injection flow rate was progressively reduced.
' Example 2
The procedure of Example 1 was followed, except that
0.5 parts of glycerol were added to 60 parts of water followed
by the addition of 2.75 parts of the sodium carboxymethyl
, methyl cellulose (Grade C7501, Henkel Chemicals Ltd.) which,
after one hour of mixing, was followed by the simultaneous
addition of 2.5 parts of caramel (65% solids) and 19.25 parts
;
of the whiting. Cast sheets were produced, as in Example 1,
with specific gravities in the range 0.3 to 0.8.
ExamE~e 3
The procedure of Example 1 was followed, except that
O. 5 parts of glycerol were added to 60 parts of water followed
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10'~'72~
by the addition of 0.75 parts of the sodium carboxymethyl
~ethyl cellulose (Grade C7501, Henkel Chemicals Ltd.), and
2 parts of methyl cellulose (Grade M2500, British Celanese
Ltd.~ viscosity 2,200 - 2,800 cps in 2% solution in water
at 20C by the method of Ostwald, specified as having a
medium degree of methoxyl substitution, the average being
in the range of 1.5 to 1.9 methoxyl groups per anhydroglucose
; unit). After one hour of mixing, 2.5 parts of caramel
(65% solids) and 19.25 parts of the whiting were added.
Sheets were produced, as in Example 1, with specific
gravities over the range 0.4 to 0.8.
Example 4
; The procedure of Example 1 was followed, except that
0.5 parts of glycerol were added to 60 parts of water
followed by the addition of 0.75 parts of methyl cellulose
, (Grade C2026, Henkel Chemicals Ltd., viscosity 2000 - 3000 cps
in 2% solution in water at 20C, specified as having a high
degree of methoxyl substitution, with an average of 1.8
methoxyl groups per anhydroglucose unit), and 2 parts of
methyl cellulose (Grade M2500, British Celanese Ltd.).
After one hour of mixing 2.5 parts of caramel (65% solids)
and 19.25 parts of the whiting were added. Sheets were
produced as in Example 1, with specific gravities over the
range 0.4 to 0.8.
' Example 5
The procedure of Example 1 was followed, except that
0.5 parts of glycerol were added to 60 parts of water
followed by 0.75 parts of sodium carboxymethyl methyl
; cellulose (Grade C7501, Henkel Chemicals Ltd.) and 2 parts
of sodium carboxymethyl cellulose (Grade F100, British
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1~47~1
Celanese Ltd., viscosity 80 - 120 cps in 1% solution in
water at 25C by the method of Ostwald, with a degree of
substitution of 0.5 to 0.7 carboxymethyl groups per anhydro- -
glucose unit). After one hour of mixing, 2.5 parts of
caramel (65% solids) and 19.25 parts of the whiting were
added. Sheets were produced as in Example 1 with specific
gravities over the range 0.4 to 0.8.
Example 6
The procedure of Example 1 was followed, except that
0.5 parts of glycerol were added to 60 parts of water con-
taining 1.25 parts (dry weight) of aqueous tobacco extract-
ables followed by 0.75 parts of sodium carboxymethyl methyl
; cellulose (Grade C7501, Henkel Chemicals Ltd.) and 2 parts
- of sodium carboxymethyl cellulose (Grade F100, British
Celanese Ltd.). After one hour of mixing, 1.25 parts of
. caramel (65% solids)and 19.25 parts of the whiting were
added. Sheets were produced as in Example 1 with specific
gravities over the range 0. 5 to 0.9.
; Eixample 7
The procedure of Example 1 was followed, except that
~,~ 0.5 parts of glycerol were added to 60 parts of water
followed by 0. 75 parts of sodium carboxymethyl methyl cellu-
lose (Grade C7501, Henkel Chemicals Ltd.) and 2 parts of
-, sodium carboxymethyl cellulose (Grade F8, British Celanese
Ltd., viscosity 5 - 9 cps in 1% solution in water at 25C
by the method of Ostwald, with a degree of substitution of
i - 0.5 to 0. 7 carboxymethyl groups per anhydroglucose unit).
After one hour of mixing, 2.5 parts of caramel (65% solids)
, and 19.25 parts of the whiting were added. Sheets were
produced as in Example 1 with specific gravities over the
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1047241
range 0.3 to 0.8.
E~
The procedure of Example 1 was followed except that
0.5 parts of glycerol were added to 60 parts of water
followed by 2 parts of sodium carboxymethyl methyl cellu-
lose (Grade C7501, Henkel Chemicals Ltd.) and 0.75 parts
of sodium carboxymethyl cellulose (Grade F100, British
Celanese Ltd.). After one hour of mixing, 2.5 parts of
caramel (65% solids) and 19.25 parts of the whiting were
added. Sheets were produced as in Example 1 with specific
gravities over the range 0. 25 to 0. 7.
Example 9
The procedure of Example 1 was followed, except that
0.5 parts of glycerol were added to 60 parts of water
followed by 2 parts of sodium carboxymethyl methyl cellu-
lose (Grade C7501, Henkel Chemicals Ltd.) and 0.75 parts
of methyl cellulose (Grade M2500, British Celanese Ltd.).
After one hour of mixing, 2.5 parts of caramel ( 65% solids)
and 19.25 parts of the whiting were added. Sheets were
` 20 produced as in Example 1 with specific gravities over the
range 0.3 to 0.7.
Example 10
- The procedure of Example 1 was followed, except that
0.5 parts of glycerol were added to 60 parts of water
followed by 0. 275 parts of sodium carboxymethyl methyl
cellulose (Grade C7501, Henkel Chemicals Ltd.) and 2.475
parts of methyl cellulose (Grade M2500, British Celanese
Ltd.). After one hour of mixing, 2.5 parts of caramel
(65% solids) and 19.25 parts of the whiting were added.
Sheets were produced as in Example 1 with specific gravities
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1047241 ~
over the range 0.4 to 0.8
F~ample 11
The procedure of Example 1 was followed, except that
0.5 parts of glycerol were added to 60 parts of water
;~ followed by 0.35 parts of sodium carboxymethyl methyl
cellulose (Grade C7501, Henkel Chemicals Ltd.) and 1.40
parts of methyl cellulose (Grade M2500, British Celanese
Ltd.). After one hour of mixing, 2.5 parts of caramel
(65% solids) ana 19.25 parts of the whiting were added.
Sheets were produced as in Example 1 with specific gravities
over the range 0. 4 to 0.8.
Example 12
The procedure of Exàmple 1 was followed, except
that 0.5 parts of glycerol was added to 60 parts of water
followed by 0.275 parts of sodium carboxymethyl methyl
cellulose (Grade C7501, Henkel Chemicals Ltd.) and 2.475
,
; parts of sodium carboxymethyl cellulose (Grade F100,
British Celanese Ltd.). After mixing for one hour, 2.5
parts of caramel (65% solids) and 19.25 parts of the,
whiting were added. Sheets were produced as in Example 1
, - .
with specific gravities over the range 0.4 to 0.8.
Example 13
The procedure of Example 1 was followed, except that
- the whiting was replaced by the same amount of aluminium
trihydrate of similar particle size. Sheets were produced
as in Example 1 with specific gravities over the range
0.4 to 0.8.
Example 14
The procedure of Example 3 was followed, except that
the whiting was replaced by the same amount of aluminium
.~ _g_
, ~ ~
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10472~1
trihydrate of similar particle size. Sheets were produced
as in Example 1 with specific gravities over the range
0.4 to 0.8.
h'xample 15
The procedure of Example 1 was followed, except that
1 part of glycerol was added to 60 parts of water followed
by 0.6 parts of methyl cellulos (Grade C2026, Henkel
Chemicals Ltd.), and 2.4 parts of sodium carboxymethyl
; cellulose (Grade F100, British Celanese Ltd.). After
mixing for one hour, 2 parts of caramel (65% solids) and
19 parts of the whiting were added. Sheets were produced
as in Example 1 with specific gravities over the range
0.4 to 0.8.
Example 16
The procedure of Example 1 was followed, except
that 0.5 parts of glycerol were added to 60 parts of water ~-
followed by the addition of 2.75 parts of methyl cellulose
(Grade MMPR2, British Celanese Ltd., viscosity 450 - 550
cps in 1.5% solution in 80 : 20 v/v methylene chloride:
methanol at 20C, specified as having a high degree of
methoxyl substitution, the average being in the range
.
1.5 to 1.9 methoxyl groups per anhydroglucose unit). After
mixing for one hour, 2.5 parts of caramel (65% solids) and
19.25 parts of the whiting were added. Sheets were pro-
duced as in Example 1, with specific gravities over the
range 0.4 to 0.8.
Example 17
The procedure of Example 1 was followed, except
that 0.5 parts of glycerol were added to 60 parts of water
; 30 followed by the addition of 2.75 parts of methyl cellulose
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~0~'7241
(Grade M2500, British Celanese Ltd.). After mixing for one
hour, 2.5 parts of caramel (65% solids) and 19.25 parts of
the whiting were added. Sheets were produced as in Example 1
with specific graviti~s over the range 0.4 to 0.8.
E ample 18
The procedure of Example 1 was followed, except that
0.5 parts of glycerol was added to 80 parts of water
followed by the addition of 2.75 parts o~ methyl cellulose
(Grade MC4000, Dow Chemical Company, viscosity 3500 -
5000 cps in 2% solution in water at 20C according to the
method of ~bbelohde, and an average methoxyl degree of
substitution of 1.6 to 1.85 methoxyl groups per anhydro-
, glucose unit). After mixing for one hour, 2.5 parts of
caramel (65% solids) and 19.25 parts of whiting were added.
; Sheets were produced as in Example 1 with specific gravities
; over the range 0.5 to 0.9.
The accompanying diagrammatic drawing illustrates
- the combination of apparatus referred to in the Examples:
Water and glycerol, followed by binder and inorganic
diluent are mixed in a planetary mixer 1. The mixture is
passed to a continuous high-shear mixer 2 with provision
indicated at 3 for the controlled introduction of air and
means indicated at 4 for the circulation through the mixer
; head of a temperature-control fluid, theatemperature being
controlled by a temperature-measuring device 5. The
mixer 2 delivers to a gate coater 6 by which the mixture,
at the controlled temperature, is applied to a continuously
moving steel band 7 on which it is carried through a series
of drying chambers 8. The casting and drying apparatus may
be of conventional type as used in the known production of
reconstituted tobacco-sheet products.
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