HK1126261B - Low ignition propensity cigarette paper - Google Patents

Description

Low-combustibility cigarette paper

Technical Field

The present invention relates to a low-flammability cigarette wrapper.

Background

There has been proposed a cigarette wrapping paper in which alginate is coated on at least a part of a base wrapping paper to reduce the air permeability of the base wrapping paper, so that it is difficult for a smoker to spread a fire to the floor due to the fire when the cigarette falls on the floor or the like without paying attention to the smoker (see japanese unexamined patent publication No. hei 7-300795).

Disclosure of Invention

However, in Japanese patent laid-open No. 7-300795, the air permeability of the alginate-coated wrapping paper was measured, and the actual burning properties of the wrapping paper were not measured.

The present inventors have studied the effect of sodium alginate among alginates on the actual burning behavior of the web, and have found that the amount of coating required to exhibit the same burning behavior varies depending on the degree of polymerization or viscosity of sodium alginate.

That is, an object of the present invention is to provide a cigarette wrapper which exhibits excellent low-burn characteristics with a relatively small coating amount.

According to a first aspect of the present invention, there is provided a low-flammability cigarette wrapper comprising a base wrapper having a basis weight (basis weight) of more than 22g/m2 and a plurality of flame retardant zones provided on one surface of the base wrapper, the flame retardant zones being spaced apart from each other, the flame retardant zones being formed by coating with a sodium alginate having a degree of polymerization of from about 500 to about 900.

According to a second aspect of the present invention, there is provided a low-combustibility cigarette wrapper paper comprising a basis weight exceeding 22g/m²And a plurality of flame-retardant zones provided on a surface of one side of the base roll paper, the flame-retardant zones being spaced apart from each other, the flame-retardant zonesThe flame zone is formed by coating with sodium alginate, and the viscosity of the sodium alginate solution with 3 wt% is above 19000cP measured at 25 deg.C.

According to a third aspect of the present invention, there is provided a low-combustibility cigarette wrapper comprising a wrapper containing 2g/m²The filler with the proportion is more than 22g/m in basis weight²A base paper having an inherent air permeability of 30 to 60C.U (コレスタ) units, and a plurality of flame-retardant zones provided on one surface of the base paper, the flame-retardant zones being spaced apart from each other, the flame-retardant zones being coated with less than 3g/m²A PFLB value measured in accordance with ASTM E-2187-04 of a cigarette using the above wrapping paper for cigarettes in an amount of sodium alginate of 0 to 10%.

Drawings

Fig. 1 is a partially cut-away perspective view of an example of a cigarette made of cigarette wrapping paper according to an embodiment of the present invention.

Detailed Description

The present invention is described in more detail below.

The cigarette paper of the present invention is formed by coating a flame retardant containing sodium alginate on a base paper and providing a plurality of flame retardant zones, the flame retardant zones being spaced apart from each other.

The base roll paper is common cigarette roll paper based on common flax pulp and other pulp. Such cigarette wrapping paper may contain 2g/m²And a generally used filler such as a carbonate such as calcium carbonate or potassium carbonate, or a hydroxide such as calcium hydroxide or magnesium hydroxide in the above ratio. The filler can be contained in the roll paper in a proportion of 2 to 8g/m². The basis weight of the base web is usually more than 22g/m². The basis weight of the paper is usually 80g/m²Below, it is preferably more than 20g/m²And at 28g/m²The following. The inherent air permeability of the roll paper is usually 30 to 60C.U. units.

The base web may also be added with a combustion regulator such as citric acid or its salt (sodium salt or potassium salt). In general, when a combustion modifier is blended, the proportion thereof in the base web is 2 wt% or less.

On the surface of one side of the base roll paper, a plurality of flame-retardant regions are provided by coating a flame retardant (sodium alginate), the flame-retardant regions being spaced apart from each other. When the roll paper is rolled into a tobacco rod, the flame retardant area extends in the longitudinal direction of the tobacco rod and is in a plurality of strip shapes which are mutually spaced in the circumferential direction of the tobacco rod; alternatively, the flame-retardant regions may be provided in the form of circular bands extending in the circumferential direction of the tobacco rod and spaced apart from each other in the longitudinal direction of the tobacco rod.

In the present invention, sodium alginate is used as the flame retardant. Alginic acid is a polyuronic acid composed of two monomers, beta-D-mannuronic acid and alpha-L-glucuronic acid. In one embodiment of the present invention, sodium alginate having a degree of polymerization (number of monomers) of 500 to 900 is used. In another embodiment of the present invention, a sodium alginate salt having a viscosity of 19000cP or more is obtained by measuring a 3 wt% aqueous solution of sodium alginate at 25 ℃. The degree of polymerization and viscosity of alginic acid are somewhat dependent. By using sodium alginate having such a high polymerization degree or viscosity, the same low flammability level can be achieved with a smaller coating amount than when using sodium alginate other than sodium alginate. The viscosity is typically below 40000 cP.

In general, the total coating weight (drying standard) of the sodium alginate flame retardant is 1m per 1m²The area of (a) is less than 3 g. In the range of 0.2 to 2g/m²The coating amount of (3) can be adjusted to achieve a sufficiently low combustibility. The wrapping paper of the present invention can provide a cigarette (a cigarette made of the wrapping paper wrapped with a cigarette filler) having a PFLB value (percent total length burn value) of 0 to 10% as measured by ASTM E-2187-04.

A cigarette wrapper according to an embodiment of the present invention comprises a wrapper containing 2g/m²The above ratioExample fillers having a basis weight of more than 22g/m²The base roll paper has inherent air permeability of 30-60 C.U.unit, and a plurality of flame retardant zones are arranged on the surface of one side of the base roll paper, and the flame retardant zones are mutually spaced. The flame-retardant region is less than 3g/m²The coated amount of (3) is 0 to 10% of PFLB value measured in accordance with ASTM E-2187-04 in a cigarette filled with a cigarette filler obtained by winding the wrapping paper with sodium alginate.

The low-combustibility wrapping paper of the present invention is wound with a cigarette filler such as shredded tobacco to form a cigarette, and the surface coated with a flame retardant is usually in contact with the tobacco.

FIG. 1 shows a cigarette formed by rolling up cigarette wrapping paper in which a flame retardant is applied in the form of a circular band.

Referring to fig. 1, a cigarette 10 has a tobacco rod 11 formed by wrapping a base wrapping paper 12 into a cylindrical shape and charging a tobacco filler 13. The tobacco rod 11 typically has a circumference of 17-26 mm and a length of 49-90 mm. On the root portion (i.e., downstream in the smoking direction) 11b of the tobacco rod 11, a conventional filter using a tissue paper 17 is attached by a conventional method.

The base web 12 is coated with a flame retardant (sodium alginate) to form a plurality of circular band-shaped regions 14 defining respective flame-retardant zones. The band-shaped flame-retardant regions 14 are formed at intervals in the longitudinal direction of the tobacco rod.

Between the adjacent circular band-shaped flame-retardant zones 14, a normal combustion zone 15, which is not coated with a flame retardant, is defined. Since this area 15 is formed by a part of the base web 12, it can burn like the base web 12 in a normal smoking state. So that region 15 generally functions as a combustion zone. For example, 2 to 3 circular band-shaped flame-retardant regions 14 may be provided. The circular band-shaped flame-retardant zone 14 may have a width of 4 to 7mm in the longitudinal direction and a thickness of usually 0.1 to 5 μm. The interval between adjacent flame-retardant zones 14 is preferably 18-25 mm.

In the cigarette shown in figure 1, the fire retardant is not applied in the region 16 spaced d from its front end. The portion of the front end portion that is not coated with the fire retardant constitutes a conventional burn zone 16, which may correspond to the area that is burned when a conventional cigarette is smoked for one or two puffs. The distance d can be 10-25 mm from the front end 11a of the tobacco rod. The inner face of the roll paper corresponding to the portion of the roll paper 12 covered by the thin paper 17 is not necessary to form the flame-retardant zone 14 intentionally.

When the cigarette 10 is lit at the tip end 11a of the cigarette rod 11 and the cigarette is burned by inhaling, the cigarette can be burned in the ordinary combustion zone 15 as in the ordinary cigarette, and the interest of smoking can be experienced. However, in the case where the lit cigarette 10 is placed on a combustible material such as a carpet, tatami, woodwork, cloth, clothing, etc., the flame retardant region 14, the combustible material heat absorption, and the expanded cut tobacco contained in the tobacco filler material, which exist in the combustion direction, interact with each other, so that the cigarette 10 extinguishes the fire and the combustion of the combustible material is suppressed.

Examples of the present invention will be described below, but the present invention is not limited to these examples.

Examples 1 to 6 and comparative examples 1 to 9

First, the polymerization degree and viscosity of sodium alginate used in the present examples and comparative examples are shown in table 1 below. The sodium alginates used are all manufactured by KIMIKA (registered trade Mark) and are purchased under the trade names ULV, IL-2, I-1, I-5 and I-S, respectively designated ALG-1, ALG-2, ALG-3, ALG-4 and ALG-5.

The viscosity shown in Table 1 is the result of placing 200g of a 3 wt% aqueous solution of sodium alginate in a 200mL or 300mL beaker, placing the beaker in a constant temperature water bath, keeping the temperature of the aqueous solution at 25. + -. 0.5 ℃, gently stirring with a glass rod so that no air bubbles are formed, standing for 10min, and measuring with a type B viscometer.

On the base roll paper (width 27mm, length 1.500m) of the method shown in table 2, a 3 wt% aqueous solution of sodium alginate was coated (printed) in stripes in a direct gravure manner at predetermined intervals of 20mm at a predetermined width of 7mm in the longitudinal direction, and a total of 56 flame retardant coating regions were provided. The total coating amount of sodium alginate was measured for the obtained roll paper in the following manner. The results are shown in Table 2.As shown in Table 2, examples 1 to 6, each 1m²The area of the flame retardant (sodium alginate) coated part, the coating amount of the flame retardant is 1.5-2 g. When the amount of the flame retardant is converted into the unit area of the roll paper, the product is multiplied by 7/27 to be 0.39-0.52 g/m²。

The obtained paper roll was wrapped with american blend type tobacco shreds (tar content 19 to 20mg in the case of no filter) to prepare a tobacco rod, which was cut so that a first coating region was disposed at a width of 5mm from the combustion end of the cigarette. Each cigarette was 59mm in length and had two zones of flame retardant coating.

The obtained cigarette was subjected to flammability test in accordance with ASTM E-2187-04 to determine PFLB values, and the results are shown in Table 2.

< measurement of Total coating amount of sodium alginate >

According to the method for quantitative analysis of sodium alginate in food, which is described in journal of food hygiene, vol.5, pp.297 to 302 (1988), the measurement was carried out in the following order without carrying out the degreasing, the dilute sulfuric acid treatment and the deproteinization treatment.

The flame retardant-coated paper roll (1.500m, width 27mm) (about 1.0g) was cut into a 5mm square, 40mL of a 1 wt% aqueous solution of sodium bicarbonate was added, and the mixture was heated in a water bath at 60 ℃ for 5min, followed by thorough mixing, stirring, and centrifugation (3500rpm, 10min, the same applies hereinafter) to obtain a supernatant (extract). The extracted residue was extracted again in the same manner to obtain a supernatant (extract), and 20mL of a 1 wt% aqueous solution of sodium hydrogencarbonate was added to the extracted residue, followed by thorough mixing and stirring to obtain a supernatant (extract). The extracts were combined 3 times, and 100mL of a 1 wt% aqueous solution of sodium bicarbonate was added as a test solution.

To 1mL of a sodium alginate standard solution (1 wt% aqueous sodium bicarbonate solution containing sodium alginate at a concentration of 0 to 0.2 mg/mL) and the test solution were added 2mL of a copper-hydrochloric acid solution (8.5M hydrochloric acid containing 0.05 wt% copper sulfate) and 1mL of a M-naphthalenediol solution (0.4 wt% aqueous 1, 3-dihydroxynaphthalene solution), respectively, and after heating in a boiling water bath for 65min, cooled in ice water, 4mL of butyl acetate was added, shaken and centrifuged.

1mL of the supernatant after centrifugation was collected, diluted with 3mL of butyl acetate, and subjected to colorimetric determination at 566nm to calculate the total coating amount.

TABLE 1

Sodium alginate stands for symbol	Degree of polymerization (number of monomers) of alginic acid	Viscosity (cP)
			ALG-1	30～180	900
ALG-2	250～400	4700
			ALG-3	550～580	19800
ALG-4	650～670	30000

[0039]

When comparative examples 2 and 3 were compared with examples 1 and 2, it was found that examples 1 and 2 were achieved with a reduced amount of flame retardant (sodium alginate) in order to achieve the same PFLB values (0-5). In contrast, when comparative examples 6 and 7 were compared with examples 5 and 6, the same coating weight (1.5 g/m)²) Examples 5 and 6, below, exhibited relatively small PFLB values.

As described above, according to the present invention, a wrapping paper for cigarettes exhibiting excellent low combustibility is provided.

Claims (14)

1. A low-flammability cigarette wrapper, wherein the cigarette wrapper comprises a basis weight of more than 22g/m²And a plurality of flame-retardant zones provided on a surface of one side of the base roll paper, the flame-retardant zones being spaced apart from each other, the flame-retardant zones being formed by coating sodium alginate having a degree of polymerization of 500 to 900.

2. A wrapping paper for cigarettes according to claim 1, wherein the base wrapping paper has a basis weight of 80g/m²The following.

3. A low-flammability cigarette wrapper, wherein the wrapper comprises a basis weight of more than 22g/m²And a plurality of flame-retardant zones provided on one surface of the base web, the flame-retardant zones being spaced apart from each other, the flame-retardant zones being formed by coating with sodium alginate, a 3 wt% aqueous solution of the sodium alginate having a viscosity of 19000cP or more as measured at 25 ℃.

4. A wrapping paper for cigarettes according to claim 3, wherein the base wrapping paper has a basis weight of 80g/m²The viscosity of sodium alginate is 40000cP or less.

5. A low-flammability cigarette wrapper as set forth in claim 1, wherein the base wrapper contains 2g/m²The filler with the proportion is used, the inherent air permeability is 30-60 C.U.unit, and the flame retardant area is coated with less than 3g/m²The amount of the sodium alginate salt is 0 to 10% by weight of PFLB value measured in accordance with ASTM E-2187-04.

6. A cigarette wrapper according to claim 5, wherein 8g/m is contained in the base wrapper²The filler is coated on the base roll paper in the following proportion of 0.2-2 g/m²A proportion of said sodium alginate.

7. A paper wrapper as defined in claim 1, wherein, when the paper wrapper is wound into a tobacco rod, the flame-retardant zone extends in a longitudinal direction of the tobacco rod to form a plurality of stripe shapes discrete from each other in a circumferential direction of the tobacco rod.

8. A paper wrapper as defined in claim 3, wherein, when the paper wrapper is wound into a tobacco rod, the flame-retardant zone extends in a longitudinal direction of the tobacco rod to form a plurality of stripe shapes spaced apart from each other in a circumferential direction of the tobacco rod.

9. A paper wrapper as defined in claim 5, wherein, when the paper wrapper is wound into a tobacco rod, the flame-retardant zone extends in a longitudinal direction of the tobacco rod to form a plurality of stripe shapes spaced apart from each other in a circumferential direction of the tobacco rod.

10. A paper wrapper as defined in claim 1, wherein, when the paper wrapper is wound into a tobacco rod, the flame-retardant zone extends in a circumferential direction of the tobacco rod to form a plurality of circular bands spaced apart from each other in a longitudinal direction of the tobacco rod.

11. A paper wrapper as defined in claim 3, wherein, when the paper wrapper is wound into a tobacco rod, the flame-retardant zone extends in a circumferential direction of the tobacco rod to form a plurality of circular bands spaced apart from each other in a longitudinal direction of the tobacco rod.

12. A paper wrapper as defined in claim 5, wherein, when the paper wrapper is wound into a tobacco rod, the flame-retardant zone extends in a circumferential direction of the tobacco rod to form a plurality of circular bands spaced apart from each other in a longitudinal direction of the tobacco rod.

13. A wrapping paper as defined in claim 1, wherein a cigarette obtained using said wrapping paper has a PFLB value measured according to ASTM E-2187-04 of 0 to 10%.

14. A wrapping paper as defined in claim 3, wherein a cigarette obtained using said wrapping paper has a PFLB value measured according to ASTM E-2187-04 of 0 to 10%.