WO2015141919A1

WO2015141919A1 - Coating composition of low ignition propensity cigarette paper, low ignition propensity cigarette paper including the same, and cigarette including the same

Info

Publication number: WO2015141919A1
Application number: PCT/KR2014/009698
Authority: WO
Inventors: Man Seok Seo; Jong Yeol Kim; Hyun Suk Cho
Original assignee: Kt & G Corporation
Priority date: 2014-03-17
Filing date: 2014-10-16
Publication date: 2015-09-24
Also published as: KR101534822B1

Abstract

A coating composition of a low ignition propensity cigarette paper, a low ignition propensity cigarette paper including the same, and a cigarette including the same are provided. The coating composition according to an exemplary embodiment of the present invention is a coating composition of a low ignition propensity cigarette paper, including a solid including one kind or more of a starch, a starch derivative, a gum, a gum derivative, and a polymer, ethanol, and water, in which a content of the solid in the coating composition is more than 27 wt% and less than 38 wt%.

Description

COATING COMPOSITION OF LOW IGNITION PROPENSITY CIGARETTE PAPER, LOW IGNITION PROPENSITY CIGARETTE PAPER INCLUDING THE SAME, AND CIGARETTE INCLUDING THE SAME

A coating composition of a low ignition propensity cigarette paper, a low ignition propensity cigarette paper including the same, and a cigarette including the same are disclosed.

In general, in order to manufacture a cigarette, various kinds of leaf tobacco are first mixed to have desired fragrance and flavor and thus be processed. Next, a cut tobacco leaf is manufactured by cutting processed leaf tobacco, and the cut tobacco leaf is rolled by a cigarette paper to manufacture a cigarette having no filter. Next, if necessary, a filter is attached to the cigarette having no filter.

The cigarette filter may include activated carbon, flavoring materials, and the like, and may be formed as a mono-filter or a multi-filter. Further, the cigarette filter is surrounded by a cigarette filter wrapping paper. The cut tobacco leaf and the cigarette filter are connected by a tipping paper, and the tipping paper may include fine holes.

The cigarette paper is manufactured so that a target tar amount and a target nicotine amount are implemented while smoking by appropriate porosity and burning property, and may be manufactured to provide intrinsic smoking flavor of the cigarette. The cigarette paper may be made of flax, wood pulp, or the like.

A material such as a starch is coated in a band form on a low ignition propensity cigarette paper, and since porosity of the coated band is low, if burning of the cigarette reaches a band portion, an amount of oxygen flowing into the cut tobacco leaf may decrease, which extinguishes the cigarette.

The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.

An exemplary embodiment is to have physical properties such as a rheology property and surface energy of a coating solution suitable for high-speed on-line coating of the low ignition propensity cigarette paper.

An exemplary embodiment is to have an excellent low ignition propensity property.

In addition to the above objects, an exemplary embodiment of the present invention may be used for implementing other objects that are not mentioned in detail.

An exemplary embodiment provides a coating composition of a low ignition propensity cigarette paper, including: a solid including at least one of a starch, a starch derivative, a gum, a gum derivative, or a polymer; ethanol; and water.

A content of the solid in the coating composition may be more than about 27 wt% and less than about 38 wt%.

Storage elasticity of the coating composition may be about 150 dyne/cm² to about 600 dyne/cm² at room temperature.

A ratio (loss elasticity/storage elasticity) of loss elasticity to the storage elasticity of the coating composition may be about 0.8 to about 2.0.

Surface energy of the coating composition may be about 25 mN/m to about 40 mN/m.

The solid may include pregelatinized corn starch and maltodextrin.

The solid may include at least one of a potato starch, a corn starch, a tapioca starch, a guar gum, a dammar gum, a polylatic acid (PLA) resin, or an acryl resin.

An exemplary embodiment provides a low ignition propensity cigarette paper including a coating portion including a solid including at least one of a starch, a starch derivative, a gum, a gum derivative, or a polymer.

Surface energy of the coating portion may be about 75 mN/m to about 85 mN/m.

The solid may include a pregelatinized corn starch and maltodextrin.

A weight ratio (pregelatinized starch:maltodextrin) of the pregelatinized corn starch and maltodextrin in the solid may be about 1:0.5 to about 1:8.0.

An exemplary embodiment provides a cigarette including a cigarette column portion, and a low ignition propensity cigarette paper surrounding the cigarette column portion and including a coating portion.

The coating portion may include a solid including at least one of a starch, a starch derivative, a gum, a gum derivative, or a polymer.

Surface energy of the coating portion may be about 75 mN/m to about 85 mN/m.

The solid may include a pregelatinized corn starch and maltodextrin.

Burning strength of the cigarette may be about 75 % or more.

Free air self-extinguishment (FASE) of the cigarette may be about 5 % to about 50 %.

An exemplary embodiment may have physical properties such as a rheology property and surface energy of a coating solution suitable for high-speed on-line coating of the low ignition propensity cigarette paper, and may have an excellent low ignition propensity property.

FIG. 1 is a perspective view schematically illustrating a cigarette according to an exemplary embodiment.

FIG. 2 is a cross-sectional view schematically illustrating the cigarette according to the exemplary embodiment.

FIG. 3 is a cross-sectional view schematically illustrating the cigarette according to the exemplary embodiment.

FIG. 4 is a graph illustrating storage elasticity (G') of each coating composition used in Examples 1 to 3.

FIG. 5 is a graph illustrating a loss elasticity/storage elasticity (G''/G') of each coating composition used in Examples 1 to 3.

FIG. 6 is a graph illustrating the storage elasticity (G'), the loss elasticity (G''), and the loss elasticity/storage elasticity (G''/G') of the coating composition used in Example 1.

FIG. 7 is a graph illustrating the storage elasticity (G'), the loss elasticity (G''), and the loss elasticity/storage elasticity (G''/G') of the coating composition used in Example 2.

FIG. 8 is a graph illustrating the storage elasticity (G'), the loss elasticity (G''), and the loss elasticity/storage elasticity (G''/G') of the coating composition used in Example 3.

The present invention will be described more fully hereinafter with reference to the accompanying drawings, in which exemplary embodiments of the invention are shown. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention. A part irrelevant to the description will be omitted to clearly describe the present invention in the drawings, and the same elements will be designated by the same reference numerals throughout the specification. In addition, the detailed description of the widely known technologies will be omitted.

A low ignition propensity cigarette paper and a cigarette according to an exemplary embodiment will be described in detail with reference to FIGS. 1 to 3.

FIG. 1 is a perspective view schematically illustrating the cigarette according to an exemplary embodiment, FIG. 2 is a cross-sectional view schematically illustrating the cigarette according to the exemplary embodiment, and FIG. 3 is a cross-sectional view schematically illustrating the cigarette according to the exemplary embodiment.

Referring to FIGS. 1 and 2, a cigarette 1 includes a cigarette column portion 10 burnt by fire and a cigarette filter portion 20 filtering cigarette smoke. The cigarette column portion 10 may be surrounded by a cigarette paper 19, and the cigarette filter portion 20 may be surrounded by a cigarette filter wrapping paper 28. The cigarette column portion 10 and the cigarette filter portion 20 may be connected by a tipping paper 29. A circumference of the cigarette may be about 5 mm to about 30 mm. The cigarette filter portion 20 may be omitted.

The cigarette column portion 10 includes a cut tobacco leaf 11 cut from leaf tobacco processed by various methods.

The cigarette filter portion 20 may include a first filter portion 21. The first filter portion 21 may be formed of an acetate tow, a paper, or the like. The cigarette filter portion 20 may be a multi-filter including two or more filter members. For example, referring to FIG. 3, the cigarette filter portion 20 may include a second filter portion 22 and a third filter portion 23. In addition, the cigarette filter portion 20 may include three filter members or four filter members.

The cigarette filter portion 20 may include an adsorbent, a flavoring agent, or the like. For example, the adsorbent may be activated carbon or the like, and the flavoring agent may be a herb fragrance material or the like. In the multi-filter, one or more filter members may include at least one of the adsorbent and the flavoring agent. For example, referring to FIG. 3, at least one of the second filter portion 22 and the third filter portion 23 may include at least one of the adsorbent or the flavoring agent.

The cigarette paper 19 includes one or more coating portions 18. For example, the coating portion 18 may have a band shape, but may have various shapes in addition to this.

The number, the width, the thickness, and the shape of the coating portion 18 may be variously changed, and an interval between a plurality of coating portions 18 may be variously changed. The coating portion 18 may reduce porosity of the cigarette paper 19, and thus if burning of the cigarette reaches the coating portion 18, an amount of oxygen flowing into the cigarette column portion 10 may decrease to extinguish the cigarette 1. The cigarette paper 19 may include the coating portion 18, which may be called the low ignition propensity cigarette paper.

Surface energy of the coating portion may be about 75 to 85 mN/m. In the aforementioned range, a coating layer of the cigarette paper may be stabilized and oxygen inflow by the coating layer may decrease to improve burning strength.

The coating composition is coated on the coating portion 18. For example, porosity of the cigarette paper 19 may be about 120 cu or less, and porosity of the coating portion 18 may be about 5 cu to about 20 cu. A thickness of a base paper of the cigarette paper may be about 30 ㎛ to about 100 ㎛, and a basis weight of the base paper may be about 15 g/m² to about 60 g/m². The thickness of the coating portion 18 may be about 5 ㎛ or less, and the basis weight of the coating portion 18 may be about 20 g/m² or less. A ratio of a weight of the coating composition to the total weight of the cigarette paper 19 and the coating composition may be about 40 wt% or less. In the case where the coating portion 18 has a band shape, a mass of the coating composition per one band may be about 2.5 mg or less.

The coating composition may include a solid including at least one of a starch, a starch derivative, a gum, a gum derivative, or a polymer, ethanol, or water.

For example, the solid may include a pregelatinized starch and maltodextrin. For example, the pregelatinized starch may be a pregelatinized corn starch. As other examples, the solid may include at least one of a potato starch, a corn starch, a tapioca starch, a guar gum, a dammar gum, a polylatic acid (PLA) resin, and an acryl resin.

The pregelatinized starch may be manufactured by rapidly drying a raw starch at high temperatures, and this treatment is called pregelatinization treatment. For example, the pregelatinized starch may be manufactured by heating a raw starch solution of about 40 % at about 100 ℃ or more and then rapidly drying the raw starch solution. The raw starch has a high viscosity property at low concentrations, is not dispersed or dissolved in cold water, and may be solidified due to a rapid aging phenomenon. On the other hand, the pregelatinized starch does not have a high viscosity property at low concentrations, is easily dispersed or dissolved in cold water, and an aging phenomenon may be delayed. Accordingly, the pregelatinized starch may improve workability of a coating process.

For example, the pregelatinized starch may be amylopectin. Amylopectin is a slightly soluble component from which soluble amylose is removed, has a net-shaped structure, and may have a property of forming a soft film. Accordingly, amylopectin may have smoothness that is strong to external impact. The pregelatinized starch may be used in a content of about 3 wt% to about 20 wt% based on the total coating composition, and when the pregelatinized starch is used in the aforementioned range, workability of the coating process may be improved.

Maltodextrin may effectively reduce an aging speed of the pregelatinized starch. Maltodextrin has excellent film forming performance and drying ability, high solubility, and a low molecular weight, and thus is advantageous in terms of permeation to inside of the cigarette paper. Since maltodextrin may be dissolved in ethanol, in the case where maltodextrin is used together with ethanol, maltodextrin may reduce a viscosity of the coating composition. Further, maltodextrin may increase bonding force between constitutional components of the coating composition. Maltodextrin may be used in a content of about 5 wt% to about 40 wt% based on the total coating composition. When maltodextrin is used in the aforementioned range, film forming performance and drying ability may be improved.

According to an amount of ethanol included in the coating composition, a solid content of the coating composition may be increased, and the viscosity of the pregelatinized starch may be reduced and be maintained. The following Table 1 describes a change in viscosity of the coating composition according to an ethanol content based on the total coating composition.

Table 1

Ethanol content (wt%)	Viscosity of coating composition according to elapsed time (cps)
	Immediately after manufacturing	4 hours	24 hours	48 hours
0	2500	8600	11,500	12,300
5	2200	5200	8100	9300
10	2100	3400	4400	5200
15	1400	2300	3400	4600
20	1400	1400	1400	1400

Further, ethanol may increase a usable period of the coating composition. Ethanol may improve drying efficiency of moisture of the coating composition, and ethanol may prevent a reduction in strength according to absorption of moisture of the cigarette paper. Ethanol may be used in a content of about 10 wt% to about 40 wt% based on the total coating composition. When ethanol is used in the aforementioned range, the viscosity of the coating composition may be effectively maintained and drying ability may be improved. Ethanol may be vaporized in a process of manufacturing the cigarette paper and thus may not be included in the coating portion 18.

The coating composition includes water. For example, water may be used in a content of about 30 wt% to about 80 wt%. Water may be vaporized in the process of manufacturing the cigarette paper and thus may not be included in the coating portion 18.

A content of the solid in the coating composition may be more than about 27 wt% and less than about 38 wt%. In the case where the content of the solid is more than about 27 wt%, the coating composition including the solid may satisfy sufficient burning strength, and may reduce occurrence of wrinkles of the cigarette and breakage during the coating process due to drying inferiority. Accordingly, a reduction in manufacturing speed of the cigarette may be suppressed. Further, in the case where the content of the solid is less than 38 wt%, the coating composition including the solid in the aforementioned range may reduce non-uniformity of the coating portion and scratches occurring on a surface of the cigarette paper by the coating composition.

A weight ratio of the content of the solid and the content of ethanol in the coating composition may be about 1:0.25 to about 1:0.85.

A storage elasticity of the coating composition may be about 150 dyne/cm² to about 600 dyne/cm² at room temperature. In the aforementioned range, the coating portion of the cigarette including the low ignition propensity cigarette paper may be formed by applying the coating composition on the surface of the cigarette paper 19 to reduce surface energy of the cigarette paper 19. Further, the coating composition having the storage elasticity in the aforementioned range may be suitable for an on-line coating process of about 10,000 CPM (cigarette per minute).

In order to uniformly apply the coating composition at a process speed of about 10,000 CPM, the storage elasticity and the loss elasticity that are appropriate to mechanical shear strength applied to a coating solution during coating should be maintained. In the aforementioned storage elasticity range of the coating composition, a rheology phenomenon of coating at a high speed is uniform, and thus surface energy of the coating composition and the coating portion may be uniform. Accordingly, the manufactured cigarette may have excellent burning strength and FASE (free air self-extinguishment).

A ratio (loss elasticity/storage elasticity) of the loss elasticity to the storage elasticity of the coating composition may be about 0.8 to about 2.0. In the aforementioned range, the coating portion of the cigarette 1 including the low ignition propensity cigarette paper may be formed by applying the coating composition on the surface of the cigarette paper 19 to reduce surface energy of the cigarette paper 19. Further, the coating composition having the ratio (loss elasticity/storage elasticity) of the loss elasticity to the storage elasticity in the aforementioned range may be suitable for the on-line coating process of about 10,000 CPM. In the case where the ratio of the loss elasticity to the storage elasticity in the aforementioned range is maintained, the uniform coating layer and surface energy may be secured in a high-speed cigarette manufacturing process. Accordingly, the manufactured cigarette may have excellent burning strength and FASE (free air self-extinguishment).

In the aforementioned range, the coating portion of the cigarette 1 including the low ignition propensity cigarette paper may be formed by applying the coating composition on the surface of the cigarette paper 19 to reduce surface energy of the cigarette paper 19. Further, the coating composition having surface energy in the aforementioned range may be suitable for the on-line coating process of about 10,000 CPM. In addition, in the aforementioned surface energy of the coating composition, non-uniformity of the coating layer caused by occurrence of a difference in surface energy of the cigarette paper that is a base material and the coating layer, and occurrence of separation and elimination of the coating layer caused by the environment such as humidity and temperatures, may be reduced.

If the coating composition is coated on the surface of the cigarette paper 19, the coating portion 18 is formed, and surface energy of the raw paper of the cigarette paper 19 before coating is reduced. For example, surface energy of the coating portion 18 in which the coating composition is coated on the surface of the cigarette paper 19 may be reduced to about 75 mN/m to about 85 mN/m.

Burning strength may be measured based on ISO 12863 and ASTM E 2187-04, which means a ratio of the cigarette not burnt to the end but extinguished in the middle among 40 pieces of cigarettes which are put on 10 filter papers. The ratio of the cigarette extinguished in the middle is increased as burning strength is increased.

Burning strength of the cigarette 1 according to the exemplary embodiment of the present invention may be about 75 % or more. In the aforementioned range, a burning property may be adjusted to be sufficiently low and thus naturally extinguish the cigarette.

Free air self-extinguishment (FASE) means the number of pieces of the cigarettes extinguished until about 3 mm of the tipping paper when the cigarette is burnt in a static burning state. In addition, a probability of extinguishing a smoldering cigarette is increased as FASE is increased. Accordingly, burning strength may be high so that coating of the low ignition propensity cigarette paper reduces a burning possibility. Further, porosity and diffusion coefficient (air diffusivity) of the coating layer may be appropriately adjusted so that the cigarette is not extinguished during a smoldering period in a smoking process.

Further, free air self-extinguishment (FASE) of the cigarette 1 according to the exemplary embodiment of the present invention may be about 5 % to about 50 %.

In the case where FASE is maintained in the aforementioned range, a possibility of extinguishing the cigarette during smoldering is low, and in the case of non-smoking, the burning property may be adjusted to be sufficiently low and thus naturally extinguish the cigarette.

Hereinafter, the present invention will be described in more detail with reference to examples, and the following examples are merely examples of the present invention and the present invention is not limited by the following examples.

Analysis of properties of coating raw paper and coating composition

Each coating composition is manufactured by changing the content of the solid in the coating composition as in the following Table 2. Each coating composition includes only the pregelatinized corn starch, maltodextrin, ethanol, and water. Next, in the case of the coating composition having the solid content of about 30 wt%, about 32 wt%, and about 35 wt%, each static viscosity, surface energy of the coating composition, surface energy of the raw paper (cigarette paper) on which the coating composition is coated, and surface energy of the coating portion on which the coating composition is coated are measured, and the results thereof are described in the following Table 3.

Table 2

Solid content (wt%)	Detailed components in solid
	Pregelatinized corn starch (wt%)	Maltodextrin (wt%)
27	10.0	17.0
30	11.0	19.0
32	12.0	20.0
35	13.0	22.0
38	14.0	24.0

Table 3

	Solid content (wt%)	Static viscosity (cPs at 25 ℃)	Surface energy of coating composition itself (mN/m)	Surface energy of raw paper (cigarette paper) (mN/m)	Surface energy of coating portion (mN/m)
Coating composition	30	1100	33.6	90	82.3
	32	1700	33.1	90	82.5
	35	2800	33.3	90	82.1

As the experimental results, it can be seen that the static viscosity is increased and surface energies of the coating composition itself and the coating portion are hardly changed but are constantly maintained according to an increase in solid content in the coating composition.

Design of coating portion of cigarette paper

The cigarette where a first coating portion is positioned at a position spaced apart from an end of the cigarette by about 17 mm and a second coating portion is positioned at a position spaced apart from an end of the filter by about 12 mm is manufactured while changing the content of the solid in the coating composition as in the following Table 4. The manufactured cigarette has a width of a band-shaped coating portion, a protrusion and depression depth of a roller, and a diffusion coefficient as described below.

Table 4

	Sample characteristic (width (mm)/roller protrusion and depression depth (㎛), solid content (wt%))	Solid in coating composition (%)	Applied roller (width (mm)/ depth (㎛))	First coating portion			Second coating portion
				Width (mm)	Roller protrusion and depression depth (㎛)	Diffusion coefficient (cm/sec)	Width (mm)	Roller protrusion and depression depth (㎛)	Diffusion coefficient (cm/sec)
Comparative Example 1	General	-	-	-	-	-	-	-	-
Example 1	5.5/18, 30 %	30	5.5/18	5.5	18	0.227	5.5	18	0.215
Example 2	5.5/18, 32 %	32	5.5/18	5.5	18	0.198	5.5	18	0.192
Example 3	5.5/18, 35 %	35	5.5/18	5.5	18	0.128	5.5	18	0.132
Comparative Example 2	5.5/18, 27 %	27	5.5/18	5.5	18	0.101	5.5	18	0.105
Comparative Example 3	5.5/18, 38 %	38	5.5/18	5.5	18	0.357	5.5	18	0.360
	Cigarette manufacturing speed (CPM)				Note
Comparative Example 1	10,000				General (coating was not performed)
Example 1	10,000				Low ignition propensity
Example 2	10,000				Low ignition propensity
Example 3	10,000				Low ignition propensity
Comparative Example 2	7000Breakage phenomenon (dry inferiority)				Low ignition propensity
Comparative Example 3	Impossible to operate (coating non-uniform)				Low ignition propensity

Evaluation of performance of cigarette

Evaluation of physical property

Physical properties of Comparative Example 1 and Examples 1 to 3 are evaluated. A result thereof is described in the following Table 5.

Table 5

	Sample characteristic (width (mm)/roller protrusion and depression depth (㎛), solid content (wt%))	Sorting condition	Physical property of products after sorting
		Cigarette weight (mg)±10	VR (%) (Ventilation rate)	EPD (mmWG) (Encapsulated pressure drop)	UPD (mmWG) (Unencapsulated pressure drop)
Comparative Example 1	General	870 - 890	79	148	64
Example 1	5.5/18, 30 %	872 - 892	78	150	66
Example 2	5.5/18, 32 %	872 - 892	78	148	64
Example 3	5.5/18, 35 %	870 - 890	78	150	65

As the experimental results, it can be confirmed that Examples 1 to 3 has the same physical properties as Comparative Example 1.

Further, although not described in Table 5, in Comparative Example 2 of Table 4, wrinkles of the cigarette occur due to drying inferiority, and in Comparative Example 3 of Table 4, manufacturing of the coating solution and the coating layer are non-uniform, and scratches occur on a portion of the surface of the cigarette paper.

Analysis of components of cigarette smoke

In the case of Comparative Example 1 and Examples 1 to 3, components of the smoke generated by burning one cigarette are analyzed, and a result thereof is described in the following Table 6.

Table 6

	Sample characteristic (width (mm)/ depth (㎛), solid content (wt%))	Tar (mg/cig.)	Nicotine (mg/cig.)	CO (mg/cig.)
Comparative Example 1	General	1.6	0.11	1.3
Example 1	5.5/18, 30 %	1.8	0.13	1.7
Example 2	5.5/18, 32 %	1.8	0.13	1.7
Example 3	5.5/18, 35 %	1.9	0.14	1.8

As the experimental result, it can be seen that contents of tar, nicotine, and carbon monoxide (CO) in the cigarette smoke are detected to be similar numerical values.

Measurement of burning strength

Burning strength of the cigarettes according to Comparative Examples 1 to 3 and Examples 1 to 3 was measured, and is described in the following Table 7. Further, FASE (free air self-extinguishment) of the cigarettes according to Comparative Examples 1 to 3 and Examples 1 to 3 is measured, and is described in the following Table 8.

Table 7

	Sample characteristic (width (mm)/depth (㎛), solid content (wt%))	Number of samples (number of pieces)	Number of cigarette pieces extinguished in the middle (%)			Number of cigarette pieces burnt to the end (%)	Extinguishing position for each coating portion
			Extinguishing on holder ①	Extinguishing on paper ②	Burning strength (natural extinguishing,①+②)	Complete burning	First	Second
Comparative Example 1	General	40	0 pieces (0.0 %)	0 pieces(0.0 %)	0 pieces (0.0 %)	40 pieces (100 %)	-	-
Example 1	5.5/18, 30 %	40	0 pieces (0.0 %)	35 pieces (87.5 %)	35 pieces (87.5 %)	5 pieces (12.5 %)	30	5
Example 2	5.5/18, 32 %	40	0 pieces (0.0 %)	37 pieces (92.5 %)	37 pieces (92.5 %)	3 pieces (7.5 %)	31	6
Example 3	5.5/18, 35 %	40	1 pieces (2.5 %)	38 pieces (95.0 %)	39 pieces (97.5 %)	1 pieces (2.5 %)	36	2
Comparative Example 2	5.5/18,27 %	40	0 pieces (0.0 %)	25 pieces (62.5 %)	25 pieces (62.5 %)	15 pieces (37.5 %)	18	7
Comparative Example 3	5.5/18,38 %	40	0 pieces (0.0 %)	40 pieces (100.0 %)	40 pieces (100.0 %)	0 pieces (0.0 %)	37	3

Table 8

	Sample characteristic (width (mm)/ depth (㎛), solid content (wt%))	Number of samples (pieces)	Burning state until 3 mm of tipping paper			Extinguishing position
			Extinguished in the middle (piece)	Complete burning (piece)	FASE (%)	First	Second	Note
Comparative Example 1	General	30	0	30	0	-	-
Example 1	5.5/18, 30 %	30	3	27	10	2	1	Extinguished at band position
Example 2	5.5/18, 32 %	30	6	24	20	4	2	Extinguished at band position
Example 3	5.5/18, 35 %	30	15	15	50	11	4	Extinguished at band position
Comparative Example 2	5.5/18, 27 %	30	0	30	0	-	-	Fail short of burning strength
Comparative Example 3	5.5/18, 38 %	30	29	1	96.6	25	4	Ratio of extinguishing in the middle is very high

Referring to Table 7, it can be seen that in Examples 1 to 3, burning strength is about 75 % or more, and thus a probability of burning is low, and burning strength is increased as the content of the solid in the coating composition is increased. However, in the case of Comparative Example 2 where the content of the solid in the coating composition is about 27 %, it is difficult to satisfy burning strength, and the wrinkles of the cigarette and breakage during the coating process occur due to drying inferiority, and thus manufacturing speed of the cigarette may be reduced. Further, in the case of Comparative Example 3 where the content of the solid in the coating composition is about 38 %, the coating portion may be non-uniform and scratches may occur on a portion of the surface of the cigarette paper by the coating composition.

Referring to Table 8, it can be seen that FASE of Examples 1 to 3 is about 10 to 50 %, which is favorable, and FASE is increased as the content of the solid in the coating composition is increased. However, in the case of Comparative Example 2 where the content of the solid in the coating composition is about 27 %, it is difficult to satisfy burning strength, and the wrinkles of the cigarette and breakage during the coating process occur due to drying inferiority, and thus the manufacturing speed of the cigarette may be reduced. Further, in the case of Comparative Example 3 where the content of the solid in the coating composition is about 38 %, the coating portion may be non-uniform, the ratio of the cigarette extinguished in the middle may be very high, and scratches may occur on a portion of the surface of the cigarette paper by the coating composition.

Rheology properties

The storage elasticity (G'), the loss elasticity (G"), and the storage elasticity/loss elasticity (G'/G") of each coating composition used in Examples 1 to 3 were measured, and are illustrated in FIGS. 4 to 8 and the following Table 9.

Table 9

	Solid content in coating composition (wt%)	Storage elasticity range (dyne/cm²,at 25℃)	Loss elasticity/storage elasticity	Surface energy of coating raw paper (mN/m)	Surface energy of coating layer (mN/m)
Used in Example 1	30	230-280	1.2-1.6	90	82.3
Used in Example 2	32	280-380	1.2-1.6	90	82.5
Used in Example 3	35	410-520	1.2-1.6	90	82.1

As the experimental result, it can be seen that the storage elasticity tends to be slightly increased as the content of the solid in the coating compositions used in Examples 1 to 3 is increased, but the loss elasticity/storage elasticity ratio is maintained at about 1.2 to 1.6.

Accordingly, it can be seen that all of the coating compositions used in Examples 1 to 3 have favorable large-scale coating workability at 10,000 CPM. In the case where the storage elasticity is the aforementioned range or more, scratches of the coating layer may occur and the coating layer may be non-uniform, and in the case where the loss elasticity/storage elasticity is the aforementioned range or more, flowability of the coating solution is increased to increase permeation of the coating solution to the inside of the cigarette paper, and thus formation of an appropriate coating layer may become difficult. Accordingly, in order to uniformly apply the coating solution at a speed of 10,000 CPM, the storage elasticity and the loss elasticity that are appropriate for mechanical shear strength applied to the coating solution during coating should be maintained.

While this invention has been described in connection with what is presently considered to be practical exemplary embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.

Claims

A coating composition of a low ignition propensity cigarette paper, comprising:

a solid comprising at least one of a starch, a starch derivative, a gum, a gum derivative, or a polymer;

ethanol; and

water,

wherein a content of the solid in the coating composition is more than 27 wt% and less than 38 wt%.
The coating composition of claim 1, wherein

storage elasticity of the coating composition is 150 to 600 dyne/cm² at room temperature.
The coating composition of claim 2, wherein

a ratio (loss elasticity/storage elasticity) of loss elasticity to the storage elasticity of the coating composition is 0.8 to 2.0.
The coating composition of claim 3, wherein

surface energy of the coating composition is 25 to 40 mN/m.
The coating composition of claim 4, wherein

the solid comprises pregelatinized corn starch and maltodextrin.
The coating composition of claim 4, wherein

the solid comprises at least one of a potato starch, a corn starch, a tapioca starch, a guar gum, a dammar gum, a polylatic acid (PLA) resin, or an acryl resin.
A low ignition propensity cigarette paper comprising

a coating portion

comprising a solid comprising at least one of a starch, a starch derivative, a gum, a gum derivative, or a polymer, and

surface energy of the coating portion is 75 to 85 mN/m.
The low ignition propensity cigarette paper of claim 7, wherein

the solid comprises a pregelatinized corn starch and maltodextrin.
The low ignition propensity cigarette paper of claim 8, wherein

a weight ratio (pregelatinized starch:maltodextrin) of the pregelatinized corn starch and maltodextrin in the solid is 1:0.5 to 1:8.0.
The low ignition propensity cigarette paper of claim 7, wherein

the solid comprises at least one of a potato starch, a corn starch, a tapioca starch, a guar gum, a dammar gum, a polylatic acid (PLA) resin, or an acryl resin.
A cigarette comprising:

a cigarette column portion; and

a low ignition propensity cigarette paper surrounding the cigarette column portion and comprising a coating portion,

wherein the coating portion comprises a solid comprising at least one of a starch, a starch derivative, a gum, a gum derivative, or a polymer, and

surface energy of the coating portion is 75 to 85 mN/m.
The cigarette of claim 11, wherein

the solid comprises a pregelatinized corn starch and maltodextrin.
The cigarette of claim 12, wherein

a weight ratio (pregelatinized starch:maltodextrin) of the pregelatinized corn starch and maltodextrin in the solid is 1:0.5 to 1:8.0.
The cigarette of claim 11, wherein

the solid comprises at least one of a potato starch, a corn starch, a tapioca starch, a guar gum, a dammar gum, a polylatic acid (PLA) resin, or an acryl resin.
The cigarette of claim 11, wherein

burning strength of the cigarette is 75 % or more.
The cigarette of claim 11, wherein

free air self-extinguishment (FASE) of the cigarette is 5 to 50 %.