PT1541043E - Filter for cigarette - Google Patents

Description

1

DESCRIPTION " CIGAR FILTER "

Technical Field The present invention relates to a cigarette filter capable of reducing the amount of aldehydes contained in the main stream of the smoke of a cigarette.

State of the art

Various chemical components are contained in the main smoking stream smoked by a smoker consuming a cigarette. It is difficult to absorb and remove aldehydes represented by formaldehyde, among these chemical components when using a custom filter on the cigarette. Therefore it is intended to remove the aldehydes from the mainstream of the cigarette.

The use of various additives in the cigarette filter has previously been attempted to absorb and remove the aldehydes contained in the main stream of cigarette smoke. However, the use of the conventional additives causes the problem of altering the flavor of the tobacco. UK Patent Application GB 2,230,687 A discloses a highly efficient tobacco smoke filter which includes a synergistic composition containing at least one of the compounds having a high activity for addition to the formaldehyde, preferably D, L- lysine, glycine, D, L-cysteine, D, L-cystine, D, L-arginine, thioglycolic acid, dimedone, and homocysteine.

In addition, UK patent application GB 2,077,737 A discloses a fibrous material for a tobacco smoke filter comprising cellulose fibers containing amino groups, wherein reactive groups are introduced into the cellulose molecule, and is made reacting the resulting cellulose with ammonia, guanidine, and certain amino acids, diamines or polyethyleneimines. U.S. Patent Number 5,860,428, on the other hand, discloses a cigarette filter including a humectant, and optionally a surfactant, wherein the humectant absorbs moisture from the tobacco smoke by providing a wet filtration of the tobacco smoke.

Finally, U.S. Patent No. 2,968,306 provides a tobacco smoke filter adapted to remove aldehyde from tobacco smoke, wherein said filter comprises a bundle of continuous beaded filaments carrying on its particle surface an amino acid material which is a non-volatile, substantially odorless solid, wherein said filter also may contain a polyhydroxy compound selected from the group consisting of the compounds glycerol, sorbitol and glycol.

Description of the Invention

It is an object of the present invention to provide a cigarette filter which enables the amount of aldehydes in the main flow rate of a cigarette to be effectively reduced while suppressing harmful effects such as the degradation of tobacco taste.

A cigarette filter according to one aspect of the present invention is characterized in that it comprises a filter medium containing a basic amino acid of arginine and a sodium lactate wetting agent, wherein the arginine is contained in an amount of 3.5 mg or more and the ratio of arginine to sodium lactate is in the range of 1: 1 to 1: 2.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 schematically illustrates the construction of an apparatus for measuring the formaldehyde contained in the main smoke flow of a cigarette in the Examples of the present invention; FIG. 2 is a cross-sectional view illustrating the construction of a cigarette used in the Examples of the present invention; FIG. 3 is a graph illustrating the delivery of formaldehyde depending on the type of a basic substance added to a cigarette filter; FIG. 4 is a graph illustrating the relationship between the amount of water added to a cigarette filter in conjunction with L-arginine, and the delivery of formaldehyde; FIG. 5 is a graph illustrating the relationship between the amount of glycerin added to a cigarette filter in conjunction with L-arginine, and increasing the amount of water in the cigarette filter; FIG. 6 is a graph illustrating delivery of formaldehyde depending on the type of wetting agent added to the cigarette filter in conjunction with L-arginine; and FIG. 7 is a graph illustrating the relationship between the ratio of L-arginine to glycerine which is added to a cigarette filter, and the amount of formaldehyde delivered.

Best Mode for Carrying Out the Invention 5

As a result of extensive investigation conducted from various points of view on various additives in attempts to decrease the aldehydes contained in the flow rate of a cigarette, the present inventors have found that a basic amino acid is an effective additive. The basic amino acid used in the present invention is arginine. Also described as basic amino acids or as the salt of a basic amino acid, for example, a salt of arginine, lysine, a salt of lysine, histidine, a salt of histidine, ornithine, an ornithine salt, citrulline, a citrulline salt, hydroxyzine and a hydroxyzine salt. Among these compounds, arginine and a salt thereof are allowed as food additives.

The present inventors have also found that the aldehydes contained in the flow of smoke from a cigarette can be more efficiently removed when the basic amino acid is used together with a wetting agent. The wetting agent used in the present invention is sodium lactate. Glycerin and sodium propionate are also described as wetting agents. A customary filtering medium, such as acetate tow, a paper filter material, or nonwoven pulp as the carrier (filter feedstock), for the basic amino acid and the wetting agent may be used. 6

It is believed that in the cigarette filter of the present invention the aldehyde content in the flow rate of a cigarette is decreased by the mechanism set forth below. In the first step, the aldehydes contained in the smoke flow of a cigarette dissolve in the water maintained by the wetting agent contained in the filter. In addition, the aldehydes dissolved in the water may react with the basic amino acid contained in the filter so as to be trapped in the filter. It should be noted that the wetting agent functions in a stable manner to maintain the water which serves to dissolve the aldehydes.

In the cigarette filter of the present invention, the basic amino acid should be contained in an amount of 3.5 mg or more because it is difficult to obtain a sufficient aldehyde-lowering effect when this amount is less than 3.5 mg.

Further, in the cigarette filter of the present invention, the ratio of the basic amino acid to the wetting agent is specified as being in the range of 1: 1 to 1: 2. When this ratio noted above has values that are not within the defined range, it is difficult to obtain a sufficient aldehyde-lowering effect.

To achieve that the filter medium contains both the basic amino acid and the wetting agent, it is possible to employ a method such as spraying, dipping and roller transfer.

It is also possible to provide the presence in the activated carbon filter medium, in addition to the basic amino acid and the wetting agent. The configuration of the filter end may be single type, dual type, multi-segmented type with three or more segments, or plunger-space-plunger type. It is possible that the basic amino acid and the wetting agent are contained in a part or all of the filtering end segments. The cigarette filter of the present invention may be a filter attached to the tobacco section of a cigarette as a mouthpiece member, or it may be a filter in the form of a mouthpiece.

Examples:

In the method of quantifying the aldehydes contained in the main smoke flow of a cigarette, which is used in the following Examples, a 2,4-dinitrophenylhydrazine derivative (DNPH), a doping agent, is determined by liquid chromatography high efficiency (HPLC). The substances that can be quantified simultaneously by this method are eight components, in particular formaldehyde, acetaldehyde, acetone, acrolein, propionaldehyde, crotonaldehyde, methylethylketone and n-butylaldehyde. In the following Examples, the disclosure is directed to formaldehyde among the aldehydes (carbonyl compounds) to be quantified.

In the first step, a trap solution is prepared by dissolving 9.51 g of 2,4-dinitrophenylhydrazine (DNPH) in 1 L of acetonitrile, followed by 5.6 ml of 60% perchloric acid and subsequently dilute the resulting solution with ultra pure water to 2 L.

The construction of the quantizing apparatus is now described, referring to FIG. 1. As shown in FIG. 1, a DNPH 12 trap solution is placed in a Drechsel-type trap 11. The Drechsel-type trap 11 has an inner volume of 250 ml, the amount of DNPH trap solution is 100 ml, and the head space volume is 150 mL. The Drechsel type trap 11 is placed in a water and ice bath 13 to cool it. The lower end of a glass tube 14 is immersed in the upper end of which a cigarette 1 is mounted within the trap solution 12 within the Drechsel-type trap 11. In addition, a glass tube 15 and a Cambridge plate 16 in communication with the volume of the Drechsel-type trap head space 11, and an automatic smoking machine 17 is connected to the Cambridge plate 16. The cigarette 1 is connected to the glass tube 14 so as to allow either the cigarette 1 to be automatically smoked under the standard smoking conditions specified in the ISO standards. To be more specific, the operation of sucking 35 mL of smoke in each smoke over seconds is repeated at a 58 second interval for a single cigarette. While the main flow of smoke is being bubbled, eight components, carbonyl compounds, are transformed into DNPH derivatives. Two cigarettes are used for quantification.

The derivatives formed in this manner are quantified by HPLC. In the first step, the trapping solution is filtered, and then this trapped trapping solution is diluted with a Trizma Base solution (4 mL of trapping solution to 6 mL of Trizma Base solution). The diluted solution is then quantitated by HPLC. The conditions used in HPLC are as follows:

Column: HP LiChrospher 100RP-18 (5μ) 250 χ 4 mm; Guard Column: HP LiChrospher 100RP-18 (5μ) 4 x 4 mm;

Column temperature: 30 ° C;

Detection wavelength: DAD 356 nm; Amount injected: 20 μl;

Three-phase gradients (solution A: ultra pure aqueous solution containing 30% acetonitrile, 10% tetrahydrofuran and 1% IPA; solution B: ultra pure aqueous solution containing 65% acetonitrile, 1% tetrahydrofuran and 1% IPA, and solution C: 100% acetonitrile).

The construction of the used cigarette will now be described with respect to the section shown in FIG. 2. As shown in FIG. 2, the cigarette has a tobacco section 20 in which cut tobacco 21 is enveloped with a tobacco wrap 22, and a filter section 30 in which a filter 31 is wrapped in forming paper 32. The filter section 30 is attached to the tobacco section 20 using an attachment paper 40. It is possible to use, for example, beaded cellulose acetate as a filter material.

When testing a cigarette prepared using a test filter having a basic amino acid or a basic amino acid salt and a wetting agent added thereto, a section of tobacco is cut through the acetate filter of a cigarette with 6 mg of tar commercially available, and the tobacco section is attached to the test filter in order to obtain a sample. An atomizer is used to add a basic amino acid or a salt of a basic amino acid and a wetting agent to the test filter.

Test 1:

An acetate filter having a length of 25 mm was prepared as the base filter. In addition, a reference filter was prepared by allowing the base filter to contain 6.5 mg of water. Filters were then prepared under test leaving the base filter to contain 6.5 mg of water plus 3.5 mg of an additive. The additive was selected from the group consisting of L-arginine, arginine glutamate, hydrazide formate, ammonia, acetamide and urea, classified as basic nitrogen-containing substances.

The filters were connected to the tobacco sections described above to prepare cigarette samples, and the delivery of formaldehyde (pg / cigarette) was quantified by the main smoking rate by cigarette, using the method described above. FIG. 3 is a graph showing the results. FIG. 3 clearly supports the fact that L-arginine, which is a basic amino acid, and arginine glutamate, which is a salt of a basic amino acid, are especially effective in decreasing the amount of formaldehyde delivered, compared to the case where in the base filter only the presence of water was allowed. Incidentally, it has been found that, in order to decrease delivery of formaldehyde, the amount of L-arginine or of arginine glutamate in the filter should preferably be 3.5 mg or more.

Test 2:

The base filter was allowed to contain 3.5 mg of L-arginine and various amounts of water. Each of the filters containing various amounts of water was connected to a section of tobacco as described above to prepare a cigarette sample and the delivery of formaldehyde (æg / cigarette) in the main smoke stream per cigarette using the method of measurement described above. FIG. 4 is a graph showing the results. As is apparent from FIG. 4, the formaldehyde can be effectively reduced in the main stream of smoke when the content of the filter in water is 5 mg or more, in the case where the filter contains 3.5 mg of L-arginine.

Test 3:

Base filters containing L-arginine and glycerin, used as a wetting agent, were provided to examine the largest amount of water in the filter. The contents of L-arginine were adjusted to 3.5 mg, 7.0 mg or 10.5 mg. The contents of glycerin were adjusted to 18 mg or 52 mg. FIG. 5 is a graph illustrating the results. FIG. 5 clearly supports that the amount of water in the filter can be increased by increasing the amount of the wetting agent, i.e. glycerin.

Test 4:

A test filter was prepared as reference, containing no wetting agent, allowing the presence in the base filter of 3.5 mg of L-arginine alone. In addition, test filters were prepared allowing the presence in the base filter of 3.5 mg of L-arginine and a wetting agent. The wetting agent was selected from the group consisting of glycerin, xylitol, sodium pantothenate, sodium PCA, sodium lactate, sodium propionate, sodium DL-malate, D-mannose and calcium chloride. The various test filters were connected to the tobacco sections described above to obtain cigarette samples, and the deliveries of formaldehyde (æg / cigarette) were quantified by the main flow rate and by cigarette using the method of measurement described above. FIG. 6 is a graph illustrating the results. As is apparent from FIG. 6, glycerol, sodium lactate and sodium propionate used as wetting agents enable the formaldehyde delivery to be effectively reduced compared to the case where the base filter contains only L-arginine per se. These wetting agents are also suitable for the manufacture of the filter.

Test 5:

Several test filters were prepared in which the base filter contained 3.5 mg of L-arginine and various amounts of sodium lactate used as a wetting agent. The ratio of sodium lactate to L-arginine was adjusted to 1: 1, 1: 2 or 1: 3.

Cigarette samples were prepared by attaching the various test filters to tobacco sections as described above, and the quantities of formaldehyde (pg / cigarette) in the main smoke flow per cigarette were quantified using the method of measurement described above. FIG. 7 is a graph illustrating the results. FIG. 7 supports the fact that the amount of formaldehyde in the main cigarette smoke flow is reduced when the base filter is allowed to contain L-arginine and sodium lactate at a ratio of 1: 1 or 1: 2.

Industrial Applicability The cigarette filter of the present invention makes it possible to effectively decrease the amount of aldehydes contained in the main flow of cigarette smoke.

Lisbon, April 2, 2014.

Claims (1)

A cigarette filter comprising a filter medium containing a basic amino acid of arginine, characterized in that it also contains a sodium lactate wetting agent and characterized in that the arginine is contained in an amount of 3.5 mg or more, and for the reason that arginine and sodium lactate are between 1: 1 and 1: 2. Lisbon, April 2, 2014.