U.S. patent application number 10/828818 was filed with the patent office on 2004-11-11 for cigarette with increased self-extinguishing tendency.
Invention is credited to Eibl, Markus.
Application Number | 20040221861 10/828818 |
Document ID | / |
Family ID | 3500437 |
Filed Date | 2004-11-11 |
United States Patent
Application |
20040221861 |
Kind Code |
A1 |
Eibl, Markus |
November 11, 2004 |
Cigarette with increased self-extinguishing tendency
Abstract
A cigarette with an increased self-extinguishing tendency,
wherein the cigarette paper has annular zones whose porosity is
reduced by the presence of a polymer, whose interfacial tension is
over 33 mJ/m.sup.2.
Inventors: |
Eibl, Markus;
(Wels/Osterreich, AT) |
Correspondence
Address: |
Thomas M. Saunders
Brown Rudnick Berlack Israels LLP
Box IP
One Financial Center
Boston
MA
02111
US
|
Family ID: |
3500437 |
Appl. No.: |
10/828818 |
Filed: |
April 21, 2004 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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10828818 |
Apr 21, 2004 |
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PCT/AT02/00126 |
Apr 24, 2002 |
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Current U.S.
Class: |
131/365 ;
162/139 |
Current CPC
Class: |
A24D 1/025 20130101 |
Class at
Publication: |
131/365 ;
162/139 |
International
Class: |
D21F 011/00 |
Foreign Application Data
Date |
Code |
Application Number |
Oct 22, 2001 |
AT |
GM 818/2001 |
Claims
1. A cigarette with an increased self-extinguishing tendency,
wherein the cigarette paper has annular zones whose porosity is
reduced by the presence of a polymer, characterised in that the
interfacial tension of the polymer is over 33 mJ/m.sup.2.
2. A cigarette according to claim 1 characterised in that the
interfacial tension is between 36 and 42 mJ/m.sup.2.
3. A cigarette according to claim 1 characterised in that the
polymer includes at least one of the compounds polyvinyl acetate,
partially hydrolysed polyvinyl acetate or polyvinyl alcohol.
4. A process for producing cigarettes according to claim 1
characterised in that the polymer dissolved in organic solvent is
applied to the cigarette paper by an intaglio printing process and
penetrates for the predominant part thereof into the cigarette
paper.
5. A cigarette according to claim 2 characterised in that the
polymer includes at least one of the compounds polyvinyl acetate,
partially hydrolysed polyvinyl acetate or polyvinyl alcohol.
Description
FIELD OF THE INVENTION
[0001] The invention relates to a cigarette with an increased
self-extinguishing tendency, wherein the cigarette paper has
annular zones whose porosity is reduced by the presence of a
polymer.
BACKGROUND OF THE INVENTION
[0002] In recent years, in particular in the USA, there has been an
increasing demand that cigarettes which are left lying around
unextinguished should not set fire to combustible materials and in
this respect in particular textiles (carpets). Although objectively
the risk of corresponding accidents is not very high, a series of
proposals have been put forward as to the way in which cigarettes
are left lying around while burning can be caused to be quickly
extinguished.
[0003] The proposal disclosed in EP 0 864 259 can be viewed as
typical in respect of the state of the art. Here a cellulose
polymer in non-aqueous solution is applied to the cigarette paper
in the form of rings which are spaced from each other. The paper is
of reduced porosity in the region of those rings and the cigarette
goes out when burning of the cigarette has progressed as far as
that ring. There is a recognised standard for the
self-extinguishing tendency of cigarettes, more specifically the
NIST test (NIST Technical Note 1436 App. D).
SUMMARY OF THE INVENTION
[0004] The object of the invention is on the one hand to satisfy
the demands of that test and on the other hand to avoid the
disadvantages of the state of the art.
DETAILED DESCRIPTION OF THE INVENTION
[0005] They are considered in particular to be that the cellulose
derivatives applied to the paper, fillers or highly ground fibres,
form at the surface of the cigarette a film, in the region of which
the thickness of the coated paper is markedly increased. In
comparison the aim is to find a material in which the desired
self-extinguishing tendency is not achieved by an external film but
by altering the paper structure in the printed region. In itself it
was not to be assumed that the actually hydrophobic polymers
penetrate into the hydrophilic paper. It is found however that,
when the interfacial tension of the polymers used is in the
proximity of that of regenerated cellulose, the polymer penetrates
into the cavity structure of the paper without a desired film
formation occurring at the surface. It is advantageous in that
respect if the polar proportion of the interfacial energy is as
high as possible. It is therefore essential for the invention that
the interfacial tension of the polymer is over 33 mJ/m.sup.2.
[0006] Inter alia polyvinyl acetate, partially hydrolysed polyvinyl
acetate or polyvinyl alcohol have proven to be particularly
suitable. Polyvinyl acetate is polar and its interfacial tension is
36.5 mJ/m.sup.2. Non-polar ethyl cellulose at 32 mJ/m.sup.2 in
contrast is as discussed film-forming and cannot be used in
accordance with the invention (all figures from: Polymer Data
Handbook, 1999, Oxford University Press Inc).
[0007] It will be appreciated that it is necessary for the selected
polymer to be applied in a sufficient amount and in a condition of
suitable geometrical distribution in order to satisfy the criteria
of the NIST test. As regards distribution of the bands, a width of
more than 4 mm is desirable, even if not critical. It will be
appreciated that the bands which stop the cigarette from burning
may also not be disposed at excessively great distances, for which
reason those distances are preferably below 20 mm.
[0008] As regards the applied amount of polymer, simple tests make
it possible to establish the values as from which the
self-extinguishing tendency is sufficient. In that respect note is
to be taken of the surprisingly established fact that a great
reduction in porosity still does not automatically result in a
substantially improved self-extinguishing tendency. It is only a
further incorporation of material into the paper that leads to an
almost abrupt increase in the self-extinguishing tendency. In this
connection, attention is directed more specifically to the examples
set out hereinafter.
[0009] The way in which the polymer is introduced into the paper is
not critical, but intaglio printing has proven to be appropriate.
By virtue of using intaglio printing the bands have a high level of
edge sharpness, and it is not possible to detect a steady increase
in the application of material from the edge to the centre. The
amount applied is adjusted by virtue of the etching depth, the
pattern repeat, the level of concentration and the viscosity of the
printing solution.
[0010] In order to improve the opacity of the paper, it is possible
to use fillers such as aluminium hydroxide, magnesium hydroxide or
titanium oxide in the printing solution. Those fillers however have
no measurable influence on the self-extinguishing tendency of
cigarettes.
[0011] The invention is described in greater detail hereinafter by
reference to examples.
EXAMPLE 1
[0012] Bands 6 mm in width are printed at a spacing of 19 mm on
cigarette paper with an initial porosity of 38 CU by means of
intaglio printing with a solution of 35% of polyvinyl acetate in
ethyl acetate (discharge viscosity 4 mm=18 s).
EXAMPLE 2
[0013] Bands 7 mm in width are printed at a spacing of 20 mm on
cigarette paper with an initial porosity of 38 CU by means of
intaglio printing with a solution of 350/% of polyvinyl acetate in
ethyl acetate (discharge viscosity 4 mm=18 s).
EXAMPLE 3
[0014] Bands 6 mm in width are printed at a spacing of 19 mm on
cigarette paper with an initial porosity of 38 CU by means of
intaglio printing with a solution of 350/% of polyvinyl acetate in
ethanol (discharge viscosity 4 mm=20 s).
EXAMPLE 4
[0015] Bands 6 mm in width are printed at a spacing of 19 mm on
cigarette paper with an initial porosity of 50 CU by means of
intaglio printing with a solution of 35% of polyvinyl acetate in
ethyl acetate (discharge viscosity 4 mm=18 s).
EXAMPLE 5
[0016] Bands 6 mm in width are printed at a spacing of 19 mm on
cigarette paper with an initial porosity of 38 CU by means of
intaglio printing with a solution of 31% of polyvinyl acetate and
7% of aluminium hydroxide in ethyl acetate (discharge viscosity 4
mm=21 s).
EXAMPLE 6
[0017] Bands 6 mm in width are printed at a spacing of 15 mm on
cigarette paper with an initial porosity of 38 CU by means of
intaglio printing with a solution of 23% of polyvinyl acetate in
ethyl acetate (discharge viscosity 4 mm=23 s).
EXAMPLE 7
[0018] Bands 6 mm in width are printed at a spacing of 15 mm on
cigarette paper with an initial porosity of 38 CU by means of
intaglio printing with a solution of 20% of polyvinyl acetate and
8% of aluminium hydroxide in ethyl acetate (discharge viscosity 4
mm=25 s).
[0019] Results:
[0020] The paper is cut into 27 mm wide coils or bobbins. Kingsize
filter cigarettes are produced therefrom.
1 No. Application mg/cm.sup.2 CU in the band SE % (NIST))**
Untreated 0 --)* 0 Example 1 0.73 4.3 100 Example 2 0.73 4.4 100
Example 3 0.73 8.1 60 Example 4 0.80 5.5 95 Example 5 0.82 5.0 100
Example 6 0.17 3.2 10 Example 7 0.25 4.8 5 )*paper porosity 39.8 CU
)**Self-extinguishing tendency in accordance with NIST Test App.
D.
[0021] Examples 6 and 7 confirm the point set out in the opening
part of this specification that a reduction in permeability as
measured in Coresta Units (CU) still does not guarantee an adequate
self-extinguishing tendency. On the contrary the latter is to be
measured directly and the application amount is to be increased
until the desired result is attained.
* * * * *