PT95754A - Cigarette paper for a product for smoking - Google Patents

Abstract

Paper which comprises a cellulose-based frame (weft), a filling agent and between 0.5 and 12% by weight of an organic acid which is added to it.

Description

Description of the invention of the United States Patent and Trademark Office of the United States Patent and Trademark Office, 3601 Commerce Road, Richmond, Virginia 23234, United States of America (inventors: Gordon H. Bokelman, Sheryl D. Baldwin, Susan S. Tafur, Robert N. Iergunson, Barbro L. Goodman, Robert M. Rogers, Barton Floyd, and Edward B. Saners, US Residents, for " SMOKING PRODUCT DUMMY "

The present invention relates to the construction of a wrapper to be used in conjunction with a smoking product, such as a cigarette, which results in the production of reduced amounts of secondary smoke and a subjectively pleasing taste. More particularly, the present invention relates to a wrapping paper for cigarettes having specific additives which give a reduced amount of secondary smoke and a taste taste, subtly pleasant.

With the evident changes in public attitudes and tolerance regarding cigarette smoking in recent years, there has been increased hostility from non-smokers to smokers. This increased hostility occurs primarily in public places where nonsmokers may be exposed to cigarette smoke.

two more smokers. This smoke is generated when the smoker sucks a cigarette and also when a cigarette rests between aspirations. The smoke generated when a cigarette is at rest is known as secondary smoke. This secondary smoke does not contribute to the smoker's pleasure, and can contribute greatly to the discomfort of non-smokers located in the vicinity.

Thus, attempts have been made to reduce the secondary smoke generated by cigarettes. These attempts were generally directed toward modifying the shroud or tobacco filler. For example, U.S. Patent No. 4,461,311 to Mathews et al. Discloses the use of " extraordinary amounts " of metal salts of alkali in the cigarette shroud for the reduction of secondary smoke. A percentage of at least 6% of the salt is required to achieve the significant benefits described in that patent. The salts disclosed include the sodium and potassium salts of numerous organic and inorganic acids. Similarly, U.S. Patent 4,561,454 to Guess discloses the use of metal salts with a high alkali content (9-20%) in a double-wound cigarette wrap to reduce secondary smoke. The salt chosen is shown in these two patents and potassium citrate. Hampl et al., In U.S. Patent No. 2,191,930, have a cigarette wrap having high levels of alkali metal salts (6-12%) combined with a high area filler. This shroud aims to reduce the production of secondary smoke. Finally, Gasey et al., In U.S. Patent 2,209,269, discloses the use of high levels of burn retardants in the shroud, in combination with tobacco fillers, comprising a minimum of 20% expanded tobacco, for the production of cigarettes which small amounts of secondary smoke. The existence of numerous attempts to obtain a cigarette which gives rise to a reduced amount of secondary smoke clearly demonstrates the industrial need for this type of cigarette. However, none of the previous attempts to achieve such a cigarette have shown to be integer 2.

satisfactory, so none has been developed with commercial success. Problems with these earlier attempts include inadequate reduction of secondary smoke and poor taste characteristics.

It would have been desirable to achieve a shroud for a smoking article to result in the production of a reduced amount of secondary smoke.

It would also have been desirable to provide a shroud for a smoking article resulting in the production of a reduced amount of secondary smoke that did not give rise to a harsh or unpleasant taste to the smoker.

It was intended to provide a shroud for a smoking article resulting in a reduced amount of secondary smoke.

It has also been envisaged to provide a shroud for a smoking article resulting in a reduced amount of secondary smoke that does not give a harsh or unpleasant taste to the smoker.

According to the present invention, there is provided a paper wrapper for a smoking article, such as a cigarette, which results in the production of a small amount of secondary smoke and a subtly pleasant taste. The paper wrapper of the present invention has an additive, such as an organic acid, or an acid salt, or a combination of a neutral salt, or acid, and an organic acid, which has been added thereto. Additionally, the shroud paper of the present invention may have a high basis weight and a low porosity, or may be a porous paper having a standardized low basis weight. The paper wrapper of the present invention may be used in cigarettes of any length or circumference and having different fillers, such as tobacco, expanded tobacco, a variety of tobacco blends, reconstituted tobacco materials, tobacco-free filler materials and combinations of the aforementioned. 3

an additive, an approximate percentage by weight of 0.5 to 12% should be used. For a maximum reduction of the secondary smoke, the organic acid should be used a set with a paper with high basic weight and low porosity. However, reductions in secondary smoke can also be achieved with the lower basic weights and higher porosities of conventional cigarette papers.

When only one acid salt is used, it should be added in an approximate amount by weight of 0.5 to 4% of the blend added to the paper. Additionally, for a maximum reduction of secondary smoke, the acid salt should be used in combination with a high base weight and low porosity paper. However, a porous paper having a standard base low weight may be used.

When an acidic or neutral salt is used in combination with an organic acid as the additive, an approximate total amount by weight of 1% to 15% of the acid or neutral salt and the organic acid to be added to the paper. A wide range of different proportions of eido or neutral salts and organic acids may be used in the composition of the additive. The combination of acidic or neutral salts with organic acids may be used in conjunction with a high base weight and low porosity paper or a standard reduced basis weight porous paper. The cigarette in which the shroud paper of the present invention may be used may have any circumferential length. For example, the circumference of the cigarette may be approximately 15mm to 25mm. Additionally, cigarettes in which the paper shroud of the present invention may be used may contain various types of filler such as tobacco, expanded tobacco, a variety of tobacco blends, reconstituted tobacco materials, tobacco-free filler materials, and combines -. mentioned above. 4

The paper shrouds of the present invention may be fabricated from flax or other cellulosic fibers and an inorganic filler, typically calcium carbonate, in an approximate weight ratio of 20% to 40%, with the preferred value of 30%. Other suitable mineral fillers or a combination of fillers may be used. If calcium carbonate is used, the performance of paper wrapping is increased when the filler area is at least 8 square meters per gram, preferably about 20 square meters per gram. The additive for the shroud paper of the present invention is an organic acid or an acid salt or a combination of an acidic or neutral salt with an organic acid. The acidic nature of the additive is important in enhancing the taste of the paper article smoking article according to the present invention and contributes to reducing the amount of secondary smoke. Thus, the acid character of the additive must be maintained. For example, the pH of the paper wrapper to which monobasic potassium phosphate and two and a half times lower (in pH units) were added to the pH of a paper wrapper to which tribasic potassium phosphate was added, with equivalent potassium ratios .

Although theoretical limitations are not desired, it is believed that the improvement in flavor resulting from the use of an organic acid, an acid salt or a combination of an acid or neutral salt with an organic acid is based on the known effect of acid additives in the presence of alkaline additives in pyrolysis of celluloses. The basic additives cause the cellulose to be cleaved into lighter compounds, including those often considered to be taste-damaging, such as aldehydes and carboxyls. The acidic additives lead to less fragmentation with the production of more disoginable levoglucosan derivative compounds and anhydrous sugars, it is not expected that any of them

adverse effects on taste.

Organic acids which may be used include, but are not limited to, the following: succinic, malonic, lactic, levulinic, pimelic, malic, citric, galacturonic, glutaric and adipic acids. It has been unexpectedly discovered that the use of organic acids in a wrapping paper does not only improve the subjective characteristics of the resulting cigarette, but also gives rise to a cigarette which produces reduced amounts of secondary smoke.

A particular example of a shroud paper in accordance with the present invention, in which only one organic acid has been used as the additive, has a basis weight of from about 25 to about 75 grams per square meter, preferably from about 40 to about 70 grams per square meter. An inorganic filler, preferably calcium carbonate, having a coverage area of at least 8 square meters per gram, preferably of about 20 square meters per gram, is used in an amount of from about 70% to 40% (by weight) , preferably 30% (by weight). The organic acid used should be added to the wrapping paper in an amount of about 0.5% to 12% (by weight), preferably 5% (by weight). The wrapping paper also has a porosity of approximately 1 to 40 Coresta units, preferably between 1 and 10 Coresta units, and more preferably between 3 and 8 Coresta units.

The acid salts used include salts of organic and inorganic acids, including the monobasic potassium and sodium salts of polyvalent organic acids (such as phosphoric, pyrophosphoric, boric and sulfuric acids and potassium and sodium monobasic salts of a organic acid (such as citric, succinic and fumaric acids)). PH of a 0.1 molar aqueous solution of the acid salt should be approximately 5.5 pH units or less. Monobasic potassium phosphate is preferably used as the acid salt. 6 acid salt.

In addition, compounds which are precursors of acid species may be used as the additive in the shroud paper, according to the present invention. Compounds which decompose thermally, generating acidic species " in situ ", can produce the desired reduction of secondary smoke combined with an acceptable flavor. Salts of polyhydric acids with at least one unstable proton can achieve the desired effect in the presence of heat or water vapor. Various esters, including phosphate esters (such as the α-D-glucoside-1-phosphate potassium salt), which are acid precursors, may also be used. Potassium monobasic phosphate is preferred as acid salt because of several advantageous characteristics. It has a low melting point and can form a stable inorganic liquid. It has been demonstrated by electron microscopic examination that this liquid coats or varnishes both the inorganic filler and the cellulosic fibers of the paper ashes. It also dehydrates at 40 ° C to form polymeric metaphosphates. Any of these characteristics enhances the ability to form a coherent gray structure thus promoting a reduction of secondary smoke.

When only one acid salt is used as the additive, it should be added in such an amount that the proportion of the cataton is between about 0.5% and 4% (by weight). The preferred range of values for the cation is dependent upon the acid salt being used. When the cation is potassium, the acid salt should be added in such an amount that preferably from about 0.5% to about 4.0% (by weight) of potassium is added. When the salt is sodium, the acid salt should be added in such an amount that preferably from about 0.8% to about 2.5% (by weight) of sodium is added. Of course, the exact amount of acid salt to be used will vary, depending on the specific salt used.

Can be used as additive 7

for the shroud paper of the present invention combinations of acid salts such as that of monobasic potassium phosphate with monobasic potassium citrate, with monobasic sodium phosphate, or with other salts which decrease the production of secondary smoke from cigarettes. In addition, combinations of other salts may be used when an aqueous solution of the mixture salts have a final pH of 5.5, or less, depending on the specific acid used.

The salt combinations, at least one of which is acidic or precursor of acidic species, may be used to reduce secondary smoke and produce an acceptable flavored cigarette. The amounts of acid salts required depend on the basis weight and the porosity of the wrapping paper, and can be determined by simple routine experimentation.

A particular example of the shrouding paper of the present invention, in which an acid salt is used as the sole additive, has a basis weight of from about 25 to about 75 grams per square meter. Preferably, the basis weight will be between about 40 and about 70 grams per square meter, approximately. Monobasic potassium phosphate is added to the paper in the shroud in an amount of about 4% to 15% (by weight), preferably 11%. An inorganic filler, preferably calcium carbonate having a coating power of at least 8 square meters per gram, preferably 20 square meters per gram, is used in an amount of about 20% to 40% (by weight), preferably 30 %. The wrapping paper also has a porosity ranging from about 1 to about 40 Coresta units, approximately, preferably from 1 to 40 Coresta units, more preferably from about 3 to about 8 Coresta units.

It has also been found that the use of an organic acid in conjunction with an acid or neutral salt, an acid species precursor or combinations of the above, as discussed in connection with the use of such acid as the sole additive, will provide a cigar - 8

with reduced amounts of secondary smoke with a subtly pleasant taste. The use of certain classes of organic acids in conjunction with acid or neutral salts unexpectedly provides for a further reduction of secondary smoke than the use of only one acid salt.

When an organic acid is used together with an acid or neutral salt, a high base weight and low porosity shroud paper or a standard base weight and porosity shroud paper may be used. A total amount of about 1% to 15% (by weight) of the acid or neutral salt and of the organic acid should be added to the paper. A wide range of different proportions of organic acid and acid or neutral salt may be used in the constitution of the additive. However, approximate percentages (by weight) of 1% to 13% of the acid or neutral salt, the precursor of acidic species or combinations thereof, and from 1% to 8% of the organic acid used are used.

When a combination of an acid or neutral salt with an organic acid is employed, the stoichiometric amounts of the materials are used so that the addition solution represents an equilibrium mixture of various salt and acid species. Thus, the salt may be initially neutral or acidic. The choice of levels of salt combinations with organic acid may be varied as desired to provide the desired secondary and subtle smoke reduction characteristics.

A particular example of the shrouding paper of the present invention in which a combination of an acid or neutral salt with an organic acid is used as an additive has a basis weight of from about 25 to about 75 grams per square meter. Preferably, will be between 40 and 70 grams per square meter, approximately. And monobasic potassium phosphate is added to the wrapping paper in an amount of about 1% to 13% (by weight). A malonic acid is added to the shroud paper in an amount of about 1% to 8% (by weight), preferably between 3% and 4%

SB-9-

(by weight). An inorganic filler, preferably calcium carbonate having a coating power of at least 8 square meters per gram, preferably 20 square meters per gram, is used in an amount of about 20% to 40% (by weight), preferably 30 %. The wrapping paper also has a porosity ranging from about 1 to about 40 Coresta units, approximately, preferably from 1 to 10 Coresta units, more preferably from about 3 to about 8 Coresta units.

The following examples illustrate the benefits of the results of the present invention. For measuring the amount of secondary smoke generated, cigarettes are allowed to pass through the secondary smoke through a chamber which is crossed by a light. A photoelectric cell detects the intensity of light transmitted during the 30mm burn of the tobacco cylinder. The average light intensity is determined during the course of the burn and compared to the light intensity when there is no smoke in the chamber. The value is referred to as extinction coefficient. The tables of the following examples show the extinction coefficients of the test samples or, in certain cases, the percentage reduction in visible secondary smoke, as calculated from the relationship between the extinction coefficient and a standard.

For the measurement of the visible secondary smoke different instruments can be used, accommodating either one or eight cigarettes. The two instruments give rise to different ranges of extinction coefficients, as evidenced by the different values for the pattern samples presented in the tables of the examples which follow. In all examples, the values of the standards were generated on the same days as the test samples were analyzed. The relative differences between the quench coefficients of the standard and test samples, or the calculated percent reduction, show the benefits of the present invention. The standard is a typical commercial cigarette of 85 or 100mm, having a shroud paper of 25 10

gram per square meter, with an approximate porosity of 30 Coresta units and a citrate additive. Test cigarettes were made manually or at a commercial cigarette manufacturer, with comparable packing densities and using the same tobacco filler as the standards. All test specimens had standard circumferences (approx 25mm) and 85mm or 100mm length, with a cellulose acetate filter of 27mra or 31.5mm. In all examples, the test cigarettes were subjectively pleasing. EXAMPLE 1

All of the shroud papers of Example 1 were made from a paper having 36% calcium carbonate filler with a coverage power of 20 square meters per gram. They have a basis weight of 63 grams per square meter and a porosity of approximately 3.2 to 3.7 Coresta units. Table 1 shows the effect of various organic acids on the visibility of the secondary smoke.

TABLE 1. EFFECT OF ORGANIC ACID AND PAPER WITH

HIGH BASIC WEIGHT AND LOW POROUSITY ON REDUCTION OF VISIBLE SECONDARY SMOKE ACID PRODUCT COEFFICIENT% REDUCTION ORGANIC EXITING NO. SMOKE SECONDARY PAPER Test sample 1 1.9% succinic acid 0.45 45 Test sample 2 1.3% malonic acid 0.36 56 Standard - 0.82 -

This example clearly shows

science of potassium monobasic phosphate, as a paper additive, in reducing visible secondary smoke. This effect is amplified in the test samples by the high basis weight and low porosity of the paper. EXAMPLE 2

All the shroud papers of Example 2 were made from paper paper having 30% filling of calcium carbonate with a coating power of 22 square meters per gram. They have a basis weight of 63 grams per square meter and a porosity of 2.2 - 2.3 units of Color-ta. Table 2 shows the effect of the addition of successively higher levels of monobasic potassium phosphate (K 2 PO 3) on the visibility of the secondary smoke.

TABLE 2 EFFECT OF A MONOBASE POTASSIUM PHOSPHATE

AND A ROLE OF HIGH BASIC WEIGHT AND LOW POROUSITY IN REDUCING VISIBLE SECONDARY SMOKE

PRODUCT% KH2P04 ON PAPER

Test sample 1 4.0 Test sample 4 8.5 Test sample 5 12.3 Standard - COEFFICIENT% OF REDUCTION OF EXTINCTION SECONDARY SMOKE 0.46 27 0.35 44 0.18 71 0.63 _ __

This example clearly shows the efficiency of the potassium phosphate monobasic, as a paper additive, in reducing visible secondary smoke. This effect is amplified in the test samples by the high basis weight and low paper porosity. 12

EXAMPLE 3

The shroud papers described in Example 3 have a 35% calcium carbonate filler having a coating power of 22 square meters per gram, a basis weight of 42.6 grams per square meter and a porosity of 5 Coresta units. Manually made cigarettes were prepared from paper samples to which monobasic potassium phosphate or a mixture of monobasic and dibasic potassium phosphates were added at comparable potassium levels. A comparison of the effect of the pH of the additives on the shroud papers was made.

TABLE 3 EFFECT OF THE pH OF ADDITIVES

ADDITIVE PRODUCT OF THE% REDUCTION PH

MORTALHA SECONDARY SMOKE SOLUTION

ADDITIVE

Test sample 4A 12.5% KH "P0, 2 4 4 32 Test sample 5A 1.7% KoHP0. 2 4 6 13 9.9% KH2P04

This example shows the beneficial results of using a more acidic salt, such as potassium monobasic phosphate instead of a mixture of salts with a pH of 6. It is not only the most acidic additive most effective to reduce visible secondary smoke, as well as Test Sample 4A is most preferred to Test Sample 5A.

A comparison of the results of Example 3 with those presented in Example 2 emphasizes the increased efficiency of the shroud papers with low porosity and high basis weight. EXAMPLE 4

All of the cigarette test samples of Example 4 have shroud papers having a 35% calcium carbonate filler having a coverage power of 22 square meters per gram, a basis weight of 45 grams per square meter and a porosity of 5 units of Coresta. Cigarettes were prepared from wrapping papers to which different potassium phosphate salts had been added as shown in Table 4. Differences in the levels of additives were made in order to make potassium levels comparable in each paper 3%).

TABLE 4 COMPARISON OF DIFFERENT PHOSPHATE SALTS

POTASSIUM PAPER ADDITIVE PAPER SMOKE% SECONDARY REDUCTION STATIC BURNING (min / roll 40mm) Test sample 6 of 9.8% KH2P04 53 7.3 Test sample 7 of 7.3% k2hpo4 44 6.0 Test sample 8 of 5.4% K3P04 37 5.8

This example shows the superiority of the monobasic potassium phosphate (KH PO), at approximately equivalent potting contents, over its di-tri-potassium forms, which are more allelic. EXAMPLE 5

All of the shroud papers of Example 5 were made of paper having 36% carbonate filler 14

of calcium having a coating power of 20 square meters per gram have a basis weight of 63 grams per square meter and a porosity of approximately 3 Coresta units.

In addition, the papers contained about 9% potassium monobasic phosphate (K 2 PO 3). Table 5 shows the effect of approximately 4% (by weight) of different organic acids in conjunction with a salt on the visible secondary smoke. Standard A had only 9% of monobasic potassium phosphate added to the paper and Pad B was a standard commercial cigarette.

TABLE 5 EFFECT OF USE OF A COMBINATION OF AN ACID

ORGANIC AND OF AN ACID SALT WITH A PAPER OF HIGH BASIC WEIGHT AND LOW POROUSITY ON THE REDUCTION OF VISIBLE SECONDARY SMOKE COEFFICIENT ADDITIVE PRODUCT EXTINCTION DUST Pimelic Sample 0.41 Test 9 acid Malonic Sample Test 10 acid 0.23 Sample of Succinic Test 11 acid 0.35 Sample of Levulinic Test 12 acid 0.52 Sample of Malic acid Test 13 acid 0.33 Sample of galacturonic acid Test 14 acid 0.32 Standard A - 0.56 1.4 * »« **. Example 5 shows the beneficial results of using an acid salt compared to conventional cigarette paper. In addition, Example 4 shows an increased benefit of using a combination of an organic acid with an e-salt to achieve maximum reduction of the secondary smoke. EXAMPLE 6

All of the shroud papers of Example 5 were made from a 30% calcium carbonate filler paper having a coating power of about 7 square meters per gram. They had a basis weight of 24 grams per square meter and a porosity of 15.9 to 25.6 Coresta units. Additionally, a neutral salt and an organic acid had been added to the papers. The levels of additives given in Table 6 reflect the stoichiometric ratio of the added materials. Table 6 shows the effect of using an organic acid and a neutral salt in combination with a low porous standard basis paper on the visible secondary smoke.

TABLE 6 EFFECT OF THE USE OF A COMBINATION OF A

ORGANIC ACID AND A NEUTRAL SALT WITH A PAPER WITH STANDARD BASIC WEIGHT AND POROSITY ON THE REDUCTION OF VISIBLE SECONDARY SMOKE

ADDITIVE PRODUCT OF% REDUCTION COEFFICIENT

SMOOTH EXTINGUISHING MORTAL

SECONDARY

Test Sample 15 Test Sample 17 9.7% Pimelate ~ 4.3% Acid Pimelic 8.8% I Pimelate 3.9% Acidic Pimelic 0.40 0.44 51 46 16

Test Sample 17

10%

Succinate 4.5% Succinic acid 0.82

Standard EXAMPLE 7

All of the cigarette test samples from Example 7 have 30% calcium carbonate filler wrapping papers having a coverage power of about 7 square meters per gram, a basis weight of 25 grams per square meter and a porosity of 20 to 30 units of Coresta, approximately. Table 7 shows the comparison of the effects of acid salts and neutral salts on a conventional commercial paper.

TABLE 7 COMPARISON OF THE EFFECTS OF AN ACID SALT AND SALT

NEUTRAL ON A PAPER WITH STANDARD BASIC WEIGHT AND POROSITY MORTALHA ADDITIVE PRODUCT% K% SECONDARY SMOKE REDUCTION Test Sample 18 9.1% K2 pimelate 3.0 15 Test Sample 19 11.2% KHpimelate 2.2 44 Test Sample 20 8.8% Malonic K 3.8 + Test Sample 21 10.5% KHMalonic 2.9 29

efficient than neutral salts. The best performance is also achieved at low percentage levels of potassium on paper. These test samples show that the acid salts can be used to reduce secondary smoke in conventional commercial cigarette papers. EXAMPLE 8

All of the cigarette test samples from Example 8 have 36% calcium carbonate filler wrapping papers having a coverage power of about 22 square meters per gram, a basis weight of 63 grams per square meter, and different levels of acidic salts of potassium, of pimelic or malonic acids. Table 8 shows the efficiency of organic acid salts in papers with high basis weight and low porosity.

TABLE 8 EFFECT OF A POTASSIUM ACID SALT OF AN ORGANIC ACID ON A PAPER OF HIGH BASIC WEIGHT AND LOW POROSITY ADDITIVE PRODUCT OF% K POROSITY COEFTCI-TQE%

EXTINGUISHING THE END OF THE DUTY

Test Sample 22 9.1% KHpimelate 1.8 2.2 0.15 10.2 80.5 Test Sample 23 5.6% KHpimelate 1.1 3.2 0.28 8.1 Test Sample 24 3.0% KHpimelate 0.6 3.9 0.38 8.5 51 Sample of 10.2% KHmalonate 2.8 4.9 0.26 7.8 66

Test 25-18 -

Test Sample 26 6.2% KHmalonate 0.7 4.8 0.45 6.9 42 Test Sample 27 3.3% KHmalonate 0.9 4.7 0.47 7.2 39 Standard __ __ __ 0.77 __ __

In example 8, it is evident that the use of an organic acid salt on a paper with high basic weight and low porosity can achieve an excellent reduction of secondary smoke without the need for a high level of potassium. Test samples from Example 8 also show that differences between acid salts can be expected. The acidic salt of potassium pimelate reduces the porosity of the paper and gives a longer static burning time (TQE), both contributing to its greater efficiency in reducing secondary smoke than that of the malonate salt. Such performance differences due to the additives can be exploited to achieve products with the most desired characteristics. EXAMPLE 9

All sample cigarette tests of Example 9 have 35% calcium carbonate filler wrapping papers having a coverage power of 22 square meters per gram, a basis weight of 45 grams per square meter, and different levels of salts potassium, pimelic or malonic acids. Table 9 shows the efficiency of the organic acid salts on papers with average basic weight and low porosity.

TABLE 9 EFFECTS OF ACID POTASSIUM ACID SALTS

ORGANICS ON MEDIUM BASIC WEIGHT ROLE AND LOW POROSITY 19

ADDITIVE PRODUCT OF% K POROSIDA- COEFFICIENT TQE% KEDUCATION OF COAT OF EXTINCTION SMOKE SECUN-

RESTA DÂRIO

Sample 9.1% Test 28 RHpimilate 1.8 3.6 0.26 9.7 66 Sample 6.1% Test 29 KHpimemate 1.2 A.4 0.32 9.0 58 Sample 3.6% Test 30 KHpimemate 0.7 5.7 0.44 8.8 43 Sample 12.0% Test 31 KHmalolate 3.3 8.0 0.44 7.3 43 Sample 6.9% Test of 32 KHmalolate 1.9 8.0 0.48 7.0 38 Sample 3.6% Test of 33 KHmalonate 1.0 7.1 0.52 7.8 32 Standard __ __ - 0.77 - -

As with high basis weight papers (see Example 8), the organic acid salts show a good reduction of the secondary smoke in the basis weight paper. EXAMPLE 10

The cigarette test samples of the 20-

- Example 10 have papers with 36% calcium filler with a coverage power of 22 square meters per gram <? a basis weight of 63 grams per square meter. Additionally, the papers contain approximately 9% K 1 PO 4 and 4% malonic acid. Table 9 compares the effects of different tobacco blends in this shroud on the reduction of secondary smoke.

TABLE 10 COMPARISON OF THE EFFECTS OF DIFFERENT TOBACCO MIXTURES ON THE REDUCTION OF SECONDARY SMOKE PRODUCT TOBACCO FILLING COEFFICIENT FILLING WEIGHT EXTINGUISHING TABLE% SECUNDRRK SMOKE REDUCTION Test Sample 34 Normal Blend 800 0.24 9.6 71 Test Sample 35 52% Expanded Blend 550 0.19 7.6 77 Standard Normal Blend 800 0.82 8.3 -

The test samples of Example 10 show that the reduction of secondary smoke achieved with the shroud papers of the present invention are equally efficient in cigarettes produced with typical tobacco filler mixtures or with other filler mixtures containing a highly expanded component. The tobacco fillers may be modified, as is known to those skilled in the manufacture of cigarettes, in accordance with the desired burning properties. 9.1

The shroud papers of Example 11 have a basis weight of 25 grams per square meter and a porosity greater than 20 Coresta units. To these papers was added an approximate amount of 5% pimelic or molonic acid. Table 11 shows the effect of using an organic acid as the sole additive of a typical commercial paper.

TABLE 11 EFFECT OF AN ORGANIC ACID ON AN

STANDARD BASIC WEIGHT AND POROSITY IN THE REDUCTION OF VISIBLE SECONDARY SMOKE ADDICTION PRODUCT OF THE MORTALHA EXTINGUISHING COEFFICIENT% SECONDARY SMOKE REDUCTION Sample Pimelic Acid 1.23 13 Test 36 Sample Malonic Acid 1.17 17 Test 37 Standard - 1.41 -

The test samples of Example 11 show the benefits of using an organic acid in combination with a standard basis weight and porosity paper. As can be seen, compared to Example 1, it is preferred to use an organic acid on a paper of high basis weight and low porosity to achieve a maximum reduction of the secondary smoke. In addition, the comparison of this example with Example 6 shows that the use of a combination of an organic acid with a salt on a basis weight paper

and porosity is preferred to achieve maximum reduction of secondary smoke. The observation of the superiority of acidic additives in reducing secondary smoke clearly represents a starting point for future teaching. The foregoing experience does not suggest the use of acidic additives for the reduction of secondary smoke and does not differentiate between mono-di- or tribasic salts of organic or inorganic acids. The acidic additives are considered unique because they act by means of a mechanism different from those proposed before, for the reduction of the secondary smoke. The importance of this difference has not been recognized by persons skilled in the development of cigarettes that produce reduced amounts of secondary smoke. In addition, the acid character of the additive may also result in a cigarette which is clearly preferable in flavor to cigarettes having more alkaline added shrouds.

It will thus be appreciated that the present invention provides cigarette wrap paper which produces reduced amounts of secondary smoke but which does not result in a bitter or unpleasant taste to the smoker. 23

Claims (16)

Paper shroud for a smoking product, characterized in that it incorporates a cellulosic web having a weight of from 40 to 75 g / m 2, a filler and an additive, said additive comprising an acid salt of an acid polyvalent or a combination of an acid salt or a neutral salt and an organic acid, or the potassium salt of α-D-glucose-1-phosphate. Paper shroud according to claim 1, characterized in that the additive is present in an amount between 1% and 15% by weight of the shroud. Paper shroud according to one of claims 1 or 2, characterized in that said additive comprises an acid salt of a polyhydric acid or a potassium salt of α-D-glucose-1-phosphate and in that said additive also comprises an organic acid. Paper shroud according to claim 3, characterized in that it contains between 1% and 3% by weight of the potassium salt of α-D-glucose-1-phosphate or the acid salt of a polyvalent acid and between 1% and 8% by weight of an organic acid. Shroud according to any of the preceding claims, characterized in that the organic acid, if any, is selected from succinic acid, malonic acid, lactic acid, levulinic acid, pimelic acid, malic acid, citric acid, galacturonic acid, glutaric acid, adipic acid or a combination thereof. Shroud according to any of the preceding claims, characterized in that the acid salt is if any, is present in an amount of from 4% by weight to 15% by weight. Paper shroud according to any preceding claim, characterized in that a 0.1 M aqueous solution of the acid salt, if any, is present in the pH range of 5.5 or less. Paper shroud according to any of the preceding claims, characterized in that the acid salt, if any, is selected from the monobasic potassium salts of carboxylic acids or polyhydric inorganic acids, preferably monobasic potassium phosphate. Paper shroud according to any one of the preceding claims, characterized in that the cation of the acidic salt, if any, comprises from 0.5% to 4% by weight and preferably from 2.2% to 4% by weight. weight of the paper shroud. Paper shroud according to any one of the preceding claims, characterized in that the cation of the acidic salt, if any, comprises from 0.8% to 2.5% by weight and preferably from 1.2% to 2% by weight. , 5% by weight of the paper wrapper. Paper shroud according to any of the preceding claims, characterized in that it has a porosity of between 1 and 40 Coresta units and a charge corresponding to an amount of between 20% and 40% by weight. Paper shroud according to any of the preceding claims, characterized in that it has a weight of between 40 and 70 g / m 2. 25 Paper shroud according to any of the preceding claims, characterized in that it has a porosity between 1 and 10 Coresta units and preferably between 2 and 8 Coresta units. Paper shroud according to any of the preceding claims, characterized in that the charge corresponds to an amount of about 30% by weight. Smoking product, characterized in that it comprises smoking material enveloped by a paper wrapper according to any one of the preceding claims. Smoking product according to claim 15, characterized in that the smoking material is selected from tobacco, expanded tobacco, reconstituted tobacco materials, non-smoking tobacco materials or combinations thereof. The applicant claims the priority of the U.S. application filed on October 31, 1989, serial number 429,317 Lisbon, October 31, 1990 OFFICIAL AGENT OF INDUSTRIAL PROPERTY 26