CA1254477A - Cigarette - Google Patents

Abstract

Abstract of the Disclosure A cigarette which produces a decreased amount of tar when being smoked. In the cigarette of the invention, a fire-retarding agent is present inside or on the outer surface of a rolling material, and a combustion promoter is present in shredded tobacco or on the inner surface of the rolling material.

Description

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The present invention relates to cigarettes.
More particularly, the present invention relates to cigarettes which have lower tar contents in the main and sub smoke flows without changing the number of puffs per cigarette and the air permeation amotmt of the rolling material durin~ smoking.
- Techniques for reducing the sub smoke flow in cigar~tte smoking are known as per U.S.A. Patent No.
4,231,377 and Japanese Patent ~isclosure (Kokai) No. 57~
163,479. A technique for reducing the main and sub smoke flows in cigarette smokin~ is known as per Japanese Patent Disclosure (Kokai) No. 43-61,699.
In U.S.A. Patent No. 4,231,37~, a magnesium compound such as magnesia or magnesium hydroxide is added to rollin~ materials to reduce the sub smoke flow. This patent does not provide any description oE the main smoke flow.
In Japanese Patent Disclosure (Kokai) No. 5~-163,4~9, the sub smoke flow is reduced using a rolling material having a small amount of air permeation (about 0.5 to 8 CORESTA). However, this technique has its disadvantages of increase in the main smoke flow and the number of puffs.
Japanese Patent Disclosure ~okai) No. 48-61,699 discloses wrapping shredded tobacco with two rolling materials. The first rolling material directly wraps the shredded tobacco and is added with up to 70%, based on the weight of the first rolling material, of activated carbon having a particle size of 0.1~ mm or less ~nd containing particles having a size of 0.44 mm or less in an amount of 25 to 50~.
The second rolling material consists of general paper and covers the first rolling material. These two rolling materials reduce the main and sub smoke flows.
However, according to this method, the thickness of the rolling material is increased and interferes with the rolling operation of a conventional cigarette making machine. This leads to a need for a modified ci~arette ~r ~2541~L77 makirlg machine or the development of a new type of cigarette makiny machine. Even if rolling with a conventional cigarette making machine can be performed, activated carbon may be separated or peeled off during rolling, thus adversely affecting the rolling conditions.
This also renders maintenance of the cigarette making machine difficult.
It i5 an object of the pre~ent invention to provide cigarettes which, when being smoked, produce a reduced amount of tar without substantially changing the number of puffs and the air permeation amount of the rolling material.
It is another object of the present invention to provi.de cigarettes which produce a reduced amount of tar when being smoked without requiring a siynificant change in cigarette making procedures or without adversely af~ectiny environmental conditions during cigarette making.
Accordingly, the invention provides a ci~arette compri~ing: shredded tobacco, a rolling material wrapping said shredded tobacco, a fire retarding agent associated with said rolling material, said fire-retarding agent being contained in said rolling material or coated on the outer surface o~ said rolling material, and a combustion promoter coated on the inner surface of said rolling material.
The cigarette accordiny to the present invention affords substantially the same number of puffs and air permeation of the rolling material duriny smoking as conventional cigarettes and can be manufactured by substantially the same method as that of conventional ci~arettes, but produces a lesser amount of tar when being smoked than conventional cigarettes.
The invention will be more fully understood from the following detailed description when taken in conjunction with the accompanying drawings, in which:

~2~ 77 Fig. l is a perspective view of a cigarette according to an embodiment of the present invention; and Figs. 2 to 4 are enlarged sectional views along the line a - a' in Fig. l for illustrating various embodiments of the presen-t invention.
As shown in Fig. 1, the cigarette 10 according to the present invention has the same outer appearance as that of a conventional cigarette. That is, the cigarette lO comprises a quantity of shredded tobacco 12 and a rolling material 14 wrapping same. The rolling material is sheetlike material used ~or encircling the shredded -tobacco and usually consis-ts o paper. A tobacco leaf of a cigar is another e~ample o a rolling material. A filter plug 16 is generally disposed at one end of the cigarette. In the cigarette of the present invention, a fire-retarding agent is present in the rolling material 14 or on the outer surface thereof, and a combustion promoter is present in -the shredded tobacco 12 or on the inner surace of the rolling material 14.
Examples of the fire-retarding agent include carbohydrates; inorganic substances such as antimony-containing compounds, ammonium phosphate and ammonium sulfamate; phos-phorus-containing compounds such as lower alkyl phosphates and hydroxymethyl phosphonium; bromine- or chlorine-containing compounds, and mixtures thereof. Among these e~amples, ; 25 carbohydrates are preferred. Particularly preferred examples o carbohydrates are cellulose derivatives such as carboxy methyl cellulose; gums such as gum arabic; pectins; or starches.
The fire-retarding agent is contained in the rolling material or is applied to the outer surface of the rolling material. The fire-retarding agent can be added to the rolling material during manufacture of rolling paper by adding it to li~uid pulp immediately before formation thereof into paper. The fire-retarding agent can be applied to the surface of the rolling material by dissolving it in a suitable solvent such as water and spraying the surface of the rolling material with the resultant solution.

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The amount of the fire-re-tarding agent to be used is generally abou-t 0.1 to 30~ and preferably about 1 to 20% based on the weight of the rolling material.
Examples o~ the combustion promoter include alkali metal salts or alkaline earth metal salts of nitric acid, tartaric acid, phosphoric acid, fumaric acia and citric acid.
The combustion promoter is added to the shredded tobacco or is coated on the inner surface of the rolling material. Addition o the combustion promoter to the shredded tobacco or coating o~ the surface of the rolling material therewith can be performed by dissolving the promoter in a suitable solven-t such as water and spraying the shredded tobacco or rolling material with the resultan-t solution.
The amount oE the combustion promoter to be used is generally abou-t 0.1 to 50~ and preferably about 1 to 35% based on the weigh-t of the rolling ma-terial.
The cigarette according -to the present invention can be one as shown in Fig. 2, wherein a combustion promoter 18 is coa-ted on the inner surEace o the rolling material 14, and a fire-retarding agent is contained in the rolling material 14. The fire-retarding agent can be added -to the rolling material, and the combustion promo-ter can be added to the shredded tobacco. Alternatively, as shown in Fig. 3, a ~ire-re-tarding agent 20 can be coated on the outer surface of the rolling material 14, and a combustion promoter 18 can be coated on the inner surface of the rolling material 14. In a further alternative as shown in Fig.
4, a fire-retarding agent 20 can be ~.æ5~4q 7 coated on the outer surface of the roll:ing matexial 14, and a combust.ion promoter can be added to the shredded tobacco 12.
The relationship be-tween an addition of a fire-retarding agent and the combustibility of the rolling material can be examined. The combustibili-ty of the rolling material was tested in accordance with the flame contact method of combustibility test method D for fiber materials according to Japanese Industrial Standard JIS-Ll091. A rolling material having a length of 200 mm and a width of 27 mm was wrapped around a cylinder with an ou-ter diameter of 8 mm, such that the rolling material cylinder had a length of 100 mm. The cylinder was placed in a stainless steel coil ~. .

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which had an inner diameter of 10 mm, a line diameter of 0.5 mm and a line pitch cf 2 mm, and which was inclined at an angle of 45 degrees to the horizontal. The lower end of this ample was brouyht into contact with a burner flame and 90% of the cylindrical rolling material was burnt in-to ash. The number of contacts of the sample with the burner flame to burn go~f the rolling material was observed.
The above operation was repeated five tirnes to calculate the average number of contacts of the sample with the flame as an index of the combustibility of the rolling material.
The type and amoun-t (% by weight based on the weight of the rolling material) of the fire-retarding agent are shown ,,j t 125~47 .~

in Table 1 below. The test results are also shown in the table~

Table 1 .
Fire-retarding AmountAverage No. of agent contact with flame _ carboxymethyl cellulose 2.9 4.7 carboxymethyl cellulose 8.3 9.3 carboxymethyl cellulose 9.8 15.0 gum arabic 2.0 1.5 gum arabic 5.3 3.5 -- ~Control) _ 1.0 _' It is seen from Table 1 above that when the fire-retarding agent is added, the number of contact of the sample with the Elame is increased, and the combustibllity is impaired.
Example Five types of filter cigarette samples A to E of standard size according to the present invention were prepared. Each of these cigarettes had a rolling portion ~the cigarette from which the filter is removed) of 63 mm lengthr an acetate filter of 17 mm length (overall length: 80 mm), and an outer circum-ferential length of the rolling portion of 25 mm. Acontrol cigarette sample F of general type was also prepared to provide a total of 6 types of cigarettes.

~S~7 The samples were subjected to the smoking test according - to the following method. The tar contents in the main and sub smoke flows were examined. The types and amounts (%
by weight) of the fire-retardin~ agent and the combustion promoter in each sample and methocls of adding them are shown in Table 2 below. The air permeation amount and combustibility ~average number of contact of the sample with the flame and the average combustion speed ~mm/sec)) of each rolling material re also shown in Table 2. The air permeation amount of the rolling material i5 expre5sed in units of CO~ESTA which represellt the amount of air ~ml) which is passed throu~h an area of 1 cm2 of the rolling material at a difEerential pressure of 100 mmH20.
Each sample wa~ mounted in an automatic smoking machine and was smoked under standard conditions. The automatic smok~ng Machine was of a type which can separately collect tars in the main and sub smoke flows produced during smoking. The standarl conditions mean a combustion length of 50 mm, a smoking frequency of once/min, a smoking volume of 35 ml/puff, and a smoking time of 2 sec/puff. The tar was collected with a Cambridge filter and the amount of the tar was measured by subtracting the water content from the weight difference of the Cambridge filter before and after tar collection, Five samples were tested each time with the au-tomatic smoking machine, and this cycle was repeated ~1 ~ZS4~L7 ~

three times. The average amount of tar in terms of weight per gram of the cigarette was calculated. The tar contents in the main and sub smoke flows and the average number of pufEs are shown in Table 3 below.

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Table 3 _ ~ 5 _ Average tar amount .in smoke (mg/g) _ Main smoke Sub smoke Total Ave~age No.
Samp~e ~low flow o~ pu~fs : 10 ~ 28.0 18.0 46.0 13.0 B 31.0 26.2 57.2 10.0 C 32.2 27.0 59.2 g.2 D 29.1 12.1 41.2lOo 3 15 E 32.0 28.1 60.0 10.3 F 33.9 31.8 65.7 10.5 _ As can be seen from Table 3, as compared to sample F, with samples A to E o the present invention the tar contents in both the main and sub smoke ~lows, are significantly decreased, particularly the tar content in the sub smoke flow which is considered to be more injurious to health.
The average numbers of puffs of samples A to E of the present invention are sub~tantially the same as that of the sample F. Particularly with samples A and D, the tar contents in the main and sub smoke flows are about 15% and 50% lower respectively, than those of sample F.

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Claims (8)

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:

1. A cigarette comprising:
shredded tobacco;
a rolling material wrapping said shredded tobacco;
a fire retarding agent associated with said rolling material, said fire-retarding agent being contained in said rolling material or coated on the outer surface of said rolling material; and a combustion promoter coated on the inner surface of said rolling material.

2. A cigarette according to claim 1, wherein said fire-retarding agent is present in an amount of about 0.1 to 30% based on the weight of said rolling material.

3. A cigarette according to claim 1, wherein said fire-retarding agent is present in an amount of 1 to 20% based on the weight of said rolling material.

4. A cigarette according to claim 1, 2 or 3, wherein said combustion promoter is present in an amount of 0.1 to 50% based on the weight of said rolling material.

5. A cigarette according to claim 1, 2 or 3, wherein said combustion promoter is present in an amount of 1 to 35% based on the weight of said rolling material.

6. A cigarette according to claim 1, 2 or 3, and further comprising a filter plug provided at one end of said cigarette.

7. A cigarette according to claim 1, 2 or 3, wherein the combustion of said fire-retarding agent and combustion promoter is such that, when the cigarette is smoked, the amount of tar in main and sub smoke flows is reduced without substantially changing the number of puffs.

8. A cigarette according to claim 1, 2 or 3, wherein the fire-retarding agent is selected from the group consisting of cellulose derivatives, pectins, gums and starches, and the combustion promoter is selected from the group consisting of alkali metal salts and alkaline earth metal salts of nitric acid, tartaric acid, phosphoric acid, fumaric acid and citric acid.