Cigarette
A cigarette includes a tobacco portion having cut tobacco wrapped with a cigarette paper sheet into a rod shape. The cut tobacco has a cut width of 1.2 mm or more. Projections having a height which corresponds to ⅓ or more of the thickness of the cigarette paper sheet are formed from the inner surface of the sheet in array partially or entirely on the surface of the cigarette paper sheet, and the sheet is arranged with the projections directed towards the cut tobacco side.
This is a Continuation Application of PCT Application No. PCT/JP03/01016, filed Jan. 31, 2003, which was published under PCT Article 21(2) in Japanese.
This application is based upon and claims the benefit of priority from prior Japanese Patent Application No. 2002-026943, filed Feb. 4, 2002, the entire contents of which are incorporated herein by reference.
BACKGROUND OF THE INVENTION1. Field of the Invention
The present invention relates to a cigarette, and more specifically to a cigarette whose tobacco mainstream smoke is reduced in carbon monoxide amount.
2. Description of the Related Art
Nowadays, various requirements are posed on cigarettes. One of such requirements is to reduce the amount of carbon monoxide in the mainstream smoke.
Jpn. Pat. Appln. KOKAI Publication No. 10-99067 (Japanese Patent No. 3206885), which was filed by the applicant of the present invention, discloses that when cut tobacco is wrapped with an embossed cigarette paper sheet, not only the falling off of cut tobacco from the tip end of the cigarette can be prevented, but also the mass ratio of carbon monoxide to tar (CO/T ratio) in the mainstream smoke can be reduced.
An object of the present invention is to provide a cigarette which can further reduce the amount of carbon monoxide in the tobacco mainstream smoke, thereby achieving a further low CO/T ratio.
BRIEF SUMMARY OF THE INVENTIONIn an attempt to achieve the above-described object, the inventors of the present invention have conducted studies in detail on embossing made on cigarette paper sheet. As a result, they have found that the above-described object can be achieved by embossing cigarette paper so as to have a certain depth or more and by setting a cut width of cutting tobacco used at a certain width or more. The present invention is based on this finding.
Thus, according to the present invention, there is provided a cigarette comprising a tobacco portion having cut tobacco wrapped with a cigarette paper sheet into a rod shape, the cut tobacco having a cut width of 1.2 mm or more, projections having a height which corresponds to ⅓ or more of the thickness of the cigarette paper sheet being formed from the inner surface of the sheet in array partially or entirely on the surface of the cigarette paper sheet, the sheet being arranged with the projections directed towards the cut tobacco side.
In the present invention, it is preferable that the cut tobacco has a cut width of 2.0 mm or more.
In the present invention, the cigarette paper usually has a thickness of 10 to 50 μm.
Further, in the present invention, the projections may each have a truncated conical shape.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING
The present invention will now be described in more detail.
The cigarette of the present invention includes a tobacco portion having cut tobacco wrapped with a cigarette paper sheet into a rod shape. In the present invention, the cut tobacco has a predetermined width, whereas the cigarette paper sheet has projections formed in array from its inner surface side to have a predetermined height. The cigarette paper sheet is disposed such that the projections are directed towards the cut tobacco side.
In the present invention, the cut tobacco pieces constituting the cut tobacco rod 12 have a cut width of 1.2 mm or more. When the cut width is less than 1.2 mm, the effect of reducing carbon monoxide in the mainstream smoke cannot be sufficiently obtained even if such cut tobacco is combined with the cigarette paper of the present invention, which will be later described. It is more preferable that the width of the cut tobacco pieces is 2.0 mm or more. In the present invention, the width of the cut tobacco pieces is usually up to 3.0 mm. It should be noted that the cut tobacco having such a width can be obtained by a conventionally known method (See, for example, Jpn. Pat. Appln. KOKAI Publication No. 2000-224978).
The cigarette paper sheet 13 wrapping the cut tobacco rod 12 has projections 13a formed in array in its inner surface, the projection having a height corresponding to ⅓ or more of the thickness of the cigarette paper sheet 13. The projections 13a are directed towards the cut tobacco rod 12 side. If the height of the projections taken from the inner surface of the cigarette paper sheet is less than ⅓ of the thickness of the sheet, the effect of reducing carbon monoxide in the mainstream smoke cannot be sufficiently obtained even if such cigarette paper is combined with the cut tobacco pieces having a width of 1.2 mm or more. In the present invention the height of the projections 13a is usually not more than 10 times the thickness of the cigarette paper sheet. The projections 13a in the cigarette paper sheet 13 are formed usually by an embossing process in which the sheet is embossed with use of means such as a knurl member. It is preferable that the embossing provides a pattern of lattice of recesses (grooves).
The cigarette paper to be embossed by the present invention is the one that is generally used for cigarettes. Such cigarette paper can have a basis weight of 15 to 60 g/m2, and it can contain a filler such as calcium carbonate in an amount of 0 to 60% by mass and a burn aid such as sodium citrate in an amount of 0 to 10% by mass. The thickness of the cigarette paper is usually 30 to 50 μm. The cigarette paper can have an air permeability of 0 to 100 CORESTA Unit (C.U.) before embossing, while it can have an air permeability of 0 to 200 C.U. after the embossing.
Needless to say, a cigarette according to the present invention may have a filter, usually used for ordinary cigarettes, attached to the proximal end of the tobacco portion using tipping paper.
The emboss applied on the cigarette paper sheet 13 shown in
In
Next, preferable sizes of the embossing pattern will now be described together with the thickness of the cigarette paper sheet 13. The preferable sizes fall within the following ranges where, as shown in
-
- A and A′: each 5 to 1000 μm (preferably, each 5 to 400 ′m)
- B and B′: each 10 to 500 μm (preferably, each 10 to 200 μm)
- C and C′: each 0 to 400 μm (preferably, each 200 to 300 μm)
- E: 10 to 300 μm (preferably, each 40 to 150 μm)
- F: 10 to 50 μm (preferably, each 25 to 40 μm).
It should be noted that the emboss depth can be measured using a probe type three-dimensional surface roughness measurement instrument (for example, SE-3AK of Kosaka Laboratory Ltd.).
Each embossed dot shown in
The cigarette of the present invention employs cut tobacco having the predetermined width and, at the same time, a cigarette paper sheet that has been specifically embossed. Thus, the amount of carbon monoxide in the mainstream smoke is synergistically reduced, and accordingly, the CO/T ratio is synergistically reduced.
The present invention will now be descried in detail by way of Examples; however, the present invention should not be limited thereto.
EXAMPLESCigarettes having a structure similar to that of an ordinary filter-tipped cigarette (diameter: 8 mm, length of tobacco rod: 59 mm, length of filter: 25 mm) were prepared using the cut tobacco and cigarette paper sheets that had the specifications described below. Tipping paper was attached to the proximal end portion of each of the cigarettes prepared, and thus cigarette samples listed in TABLE 1 below were prepared. Five cigarette samples were prepared for each cigarette specification.
<Cut Tobacco>
Tar value: 5 mg per cigarette
Width of cut piece: 0.8 mm or 2 mm
<Cigarette Paper A (Not Embossed)>
Basis weight: 22 g/m2
Filler: calcium carbonate
Amount of filler used: 28% by mass
Burn aid: sodium citrate
Amount of burn aid added: 1% by mass
Thickness: 32 μm
Air permeability: 24 C.U.
<Cigarette Paper B (Embossed)>
Basis weight: 22 g/m2
Filler: calcium carbonate
Amount of filler used: 28% by mass
Burn aid: sodium citrate
Amount of burn aid added: 1% by mass
Thickness: 32 μm
Emboss pitch: 0.64 mm
Emboss depth: 85 μm
Emboss shape: tetragonal prismoid
Emboss dot width (corresponding to A+2B in
Air permeability: 80 C.U.
Wrapping state: wrapping with the projections on cut tobacco side
Each of the cigarette samples was placed vertically on a smoking device (RGC system R26 of Borgwaldt Co.) and ignited at its distal end. Each sample was statically burned until its char line reaches a point 5 mm away from the distal end of the tipping paper and at that point each sample was puffed one time (puffing time: 2 seconds; puffed volume 35 mL), in order to eliminate the effects of dilution and diffusion from the cigarette paper sheet. The mainstream smoke was collected in a gas bag (Tedler bag of Supelco Co.). The collected mainstream smoke was subjected to a gas chromatography (Micro GC M200H of Agilient Co.) to measure the amount of carbon monoxide (CO). The results are shown also in TABLE 1 below.
As can be seen from
As described above, according to the present invention, there is provided a cigarette that produces a further less amount of carbon monoxide in its tobacco mainstream smoke.
Claims
1. A cigarette comprising a tobacco portion having cut tobacco wrapped with a cigarette paper sheet into a rod shape, the cut tobacco having a cut width of 1.2 mm or more, projections having a height which corresponds to ⅓ or more of the thickness of the cigarette paper sheet being formed from the inner surface of the sheet in array partially or entirely on the surface of the cigarette paper sheet, the sheet being arranged with the projections directed towards the cut tobacco side.
2. The cigarette according to claim 1, wherein the cut tobacco has a cut width of 2.0 mm or more.
3. The cigarette according to claim 1, wherein the cut tobacco has a cut width of up to 3.0 mm.
4. The cigarette according to claim 1, wherein the projections have a height of up to 10 times the thickness of the cigarette paper sheet.
5. The cigarette according to claim 1, wherein the cigarette paper sheet has a thickness of 10 to 50 μm.
6. The cigarette according to claim 1, wherein the projections each have a truncated conical shape.
Type: Application
Filed: Aug 3, 2004
Publication Date: Jan 6, 2005
Inventors: Yoshiyuki Yamada (Yokohama-shi), Masafumi Tarora (Yokohama-shi), Atsushi Nagao (Yokohama-shi)
Application Number: 10/909,398