CA1119358A - Post-treatment of humic acid-dyed paper - Google Patents
Post-treatment of humic acid-dyed paperInfo
- Publication number
- CA1119358A CA1119358A CA000326263A CA326263A CA1119358A CA 1119358 A CA1119358 A CA 1119358A CA 000326263 A CA000326263 A CA 000326263A CA 326263 A CA326263 A CA 326263A CA 1119358 A CA1119358 A CA 1119358A
- Authority
- CA
- Canada
- Prior art keywords
- paper
- humate
- humic acid
- solution
- stained
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- D—TEXTILES; PAPER
- D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
- D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
- D21H5/00—Special paper or cardboard not otherwise provided for
- D21H5/12—Special paper or cardboard not otherwise provided for characterised by the use of special fibrous materials
- D21H5/14—Special paper or cardboard not otherwise provided for characterised by the use of special fibrous materials of cellulose fibres only
- D21H5/16—Tobacco or cigarette paper
-
- D—TEXTILES; PAPER
- D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
- D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
- D21H17/00—Non-fibrous material added to the pulp, characterised by its constitution; Paper-impregnating material characterised by its constitution
- D21H17/03—Non-macromolecular organic compounds
- D21H17/05—Non-macromolecular organic compounds containing elements other than carbon and hydrogen only
- D21H17/14—Carboxylic acids; Derivatives thereof
-
- D—TEXTILES; PAPER
- D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
- D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
- D21H21/00—Non-fibrous material added to the pulp, characterised by its function, form or properties; Paper-impregnating or coating material, characterised by its function, form or properties
- D21H21/14—Non-fibrous material added to the pulp, characterised by its function, form or properties; Paper-impregnating or coating material, characterised by its function, form or properties characterised by function or properties in or on the paper
- D21H21/28—Colorants ; Pigments or opacifying agents
Abstract
ABSTRACT OF THE DISCLOSURE
Humic acid-dyed paper suitable for use as wrappers for smoking articles is post treated with magnesium sulfate to fix or render the humic acid insoluble. Paper treated in this manner provides a product of acceptable brown colour.
Smoking articles wrapped in the treated paper evolve a reduced amount of carbon monoxide on smoking under normal conditions in comparison to currently available brown papers stained with humic acid.
Humic acid-dyed paper suitable for use as wrappers for smoking articles is post treated with magnesium sulfate to fix or render the humic acid insoluble. Paper treated in this manner provides a product of acceptable brown colour.
Smoking articles wrapped in the treated paper evolve a reduced amount of carbon monoxide on smoking under normal conditions in comparison to currently available brown papers stained with humic acid.
Description
1~9~
-- 1, --POST-TREATMENT OF HUMIC ACID-DYED PAPER
Technical Field -; The invention relates to improved methods for staining papers suitable for use as wrappers for smoking articles wherein alkali humates are utilized. The humates are rendered insoluble on the paper using solutions of magnesium sulfate.
Background of the Prior Art The use of humic acid and fractions thereof as dyes is !,, well known. ("Recent Progress in the Chemistry of Natural and ' 10 Synthetic Coloring Matters," T.S. Gore et al. eds., Academic Press, N.Y. 1962, pps. 99-112.) Recently, a variety of cigar-ettes manufactured with brown paper wrappers have enjoyed increased popularity among smokers, and some of these cigarettes are fabricated using brown wrappers stained with humic acid.
; Processes for staining cigarette paper brown have included the ; use of dyes such as synthetic azo dyes, dyes produced from walnut shells, caramel, tannic acid and the like. However, .~ ~
the aforementioned stains or dyes are undesirable for a variety of reasons. First, the azo dyes, which contain large amounts of nitrogen, may produce undesirable pyrolysis products and, therefore, could be unsuitable for use in smoking articles.
Secondly, the amount of caramel required to produce the -~ ~k ..., - . .
-~: .
~1~93,~,8 desired intensity of brown color considerably inhibits the burn rate of the paper. The use of such stains as tannlc acid may provide the desired brown color; however, treatment of this type simultaneously reduces the porosity of the paper thereby also reducing the rate of combustion. In addition, adverse affects on the gas phase composition are also noted (see Austrian Patent 175,148).
By definition, humic acids are allomelanins found in soil, peat, and low-rank coal. They are generally alkali soluble and precipitated in the presence of acids. From a chemical standpoint, hu~ic acids generally consist of a mixture of complex macro-molecules characterized as having polymeric phenolic structures with the ability to chelate with metals.
In addition, humic acids have a strong base-binding power, and thision-exchange capability can be used advantageously in their use as dyes. There are many variations of humic acid depending upon differences in the plant remains from which they originate as well as the soil, climate, microflora, drainage, etc.
Humic acids, by nature, are intensely chocolate brown in color; and because of their natural origin, they are particular ly preferred over synthetic dyes as staining pigments for producing brown wrappers or papers for smoking products.
Generally, an a~lkaline solution is prepared by mixing the powdery humic acid with an alkali metal hydroxide, i.e., sodium hydroxide, to form a soluble humate salt. This solution is used to impregnate the paper on one or both sides, and this is followed by a fixing step, generally with salts such as ., , .,, ~, . .. .
.. , : : .
r~ -1~193~8 aluminum, calcium, iron, and the like. In essence, sodium ions are partially exchanged for alkaline earth or metal ions in the fixing process, thus leaving a water insoluble humate salt on the paper.
Hennig in Allgemeine Papier-Rundschau, No. 31:1027 (21 August 1967) describes methods for staining paper, and espec-ially paper suitable for cigarette wrappers, with Sap Brown ( also termed "nut stain" or humates) at about neutral pH.
The Sap Brown may be rendered insoluble on the paper by fixing with aluminum or iron sulfate. We have found that certain disadvantages are encountered when utilizing the foregoing method of Hennig. For instance, when aluminum sulfate is employed as the fixing agent, an undesirable masking of the rich brown color is observed.
Others have suggested various cations that are useful for precipitating humates, and they include chromium, magnesium, ; lead, copper, calcium, potassium, and the like. However, none have suggested that any one of the cations listed above would be suitable for use as a fixing agent when staining paper for ultimate use in smoking articles. Moreover, no suggestion has been made to indicate that one of these cations, when used as a fixing agent, might be preferable for use in smoking articles due to improved smoking characteristics, improved appearance, or lowered gas phase constituents on smoking.
Analy~ cal studies using humic acid-treated brown wrap-pers have indicated in some instances a tendency toward increased gas phase constituents. Various attempts have been made to reduce constituents, such as carbon monoxide, by ,:
~ ' ' ''' ,'', '' ' .' ~' . .
s~
using more efficient filter elements, by increasing the degree of ventilation in filters, or by increasing the poros-ity of the paper or wrapper, etc. However, none of these me1:hods have proven to be entirely satisfactory.
Brief Summary of the Invention This invention concerns the improvement of humic acid-treated paper or sheet material in which tobacco or any other smoking product is rolled for the fabrication of cigarettes, cigars, or the like.
The invention relates specifically to a process for treating humic acid-dyed brown paper suitable for use as wrappers for smoking articles wherein some of the products of pyrolysis are substantially reduced. In studies with cigar-ettesmade with commercially available humic acid-stained papers, it was observed that on pyrolysis the burning papers produced more carbon monoxide than conventional white cigarette wrappers. In an effort to identify the cause, experiments were designed to study a number of parameters related to dyeing with humic acid. The concentration and composition of humic acid was varied as well as the pH of the staining solution;
and in addition, a variety of cations (fixing agents) that render the humic acid insoluble and colorfast on the paper, were utilized in an attempt to reduce gas phase delivery.
From the results obtained, a total system for coating cigar-ette wrappe~s having reduced gas phase constituents has been ; developed an~ will be described in detail hereinbelow.
Thus, it is an object of this invention to provide a ; method for producing a humic acid-coated paper or smoking ' ' ! ~ .' . . ' ' , ' ' ~ . . ~, ' ' !
, ~ . ., ' ~ ' ~ . .' . . ' . . ' ":
' 1 ' ' ' . , ~
3~;8 wrapper whereby smoking articles produced from said paper can be materially improved.
It is a further object of this invention to provide methods and means that individually operate to provide a more desirable brown paper or wrapper from the standpoint of gas phase delivery whereby such ~as phase consitituents, such as carbon monoxide, are subtantially reduced.
It is yet a further object of this invention to provide a method for fixing humates on paper whereby a desirable color intensity is obtained with a concomitant reduction in gas phase constituents such as carbon monoxide.
Other objects and advantages will be discussed and des-cribed in detail hereinbelow.
Detailed Description of the Invention In the practice of the present invention, commercially available humic acid is suspended in water with stirring. The mixture is then centrifuged to recover the insoluble humic acid, and the acid-soluble materials are discarded. Experiment-ation indicates that the acid-soluble fraction is undesirable in that at certain concentrations there is a tendency towards gel formation, and, in addition~ this fraction does not apprec-iably improve color depth or intensity of the final staining solution.
The acid-insoluble humic acid fraction is generally dried, weighed, and then suspended in water. The pH of the suspension is adjusted with a base such as sodium, potassium, or ammonium hydroxide, with sodium hydroxide being preferred. The final pH of the staining solution should be between about 7 and 8 :, ~ ,. . ' . , ;
`\
93~8 for optimum results. There appears to be a tendency towards increased carbon monoxide delivery as the pH of the staining solution is increased over about a pH of 8. Stabilization of the pH of the solution may require about 8 to about 20 hours with continual stirring.
Just prior to the actual staining or dyeing of the paper, the alkaline humate solution may be centrifuged to remove any remaining insoluble materials. The insoluble materials are dried and weighed. The staining solution containing the alkali humate is adjusted by the addition of water to give a final concentrationofabout 12 to 16~ humate and preferably about 14~ humate by weight.
The actual staining process may be carried out utilizing a conventional size press wherein standard bobbins of cigarette paper are passed through a staining bath containing the alkali humate at a predetermined speed to insure that the desired amount of staining solution is retained on the paper. The paper may be stained on one or both sides depending on the desired effect to be achieved.
In an alternate approach, sodium humate is added to a slurry of purified cellulose pulp, and the slurry is used as a furnish in a conventional papermaking machineto produce a brown paper suitable for use in the fabrication of smoking products.
In a preferred embodiment of the present invention, the alkali humate is fixed on the paper by treatment with a dilute solution of magnesium sulfate. This salt post-treatment is preferably carried out after the paper has been stained and dried by conventional methods. Although calcium salts are well known fixing agents for alkali humates, we have found . . ..
, ..
, , ' , ' ', ~ ' .:
,: ,. ..
, : ::: ;
11~358 magnesium sulfate unexpectedly superior for use as a fixing agent when preparing paper for ultimate use in smoking articles.
Magnesium sulfate at a concentration of about l to 3%, and preferably about 2% by weight, provided consistently lower carbon monoxide delivery when compared to calcium chloride or magnesium acetate. Tests were conducted using aluminum sulfate as a fixing agent; and although carbon monoxide deliveries were acceptable, it was noted that at even the lowest concent-ration possible for fixing the alkali humate, the aluminum salt caused an unacceptable while film on the paper.
Following the fixing step the paper may be washed with water to remove excess magnesium sulfate or alkali sulfate salts, i.e., sodium sulfate, which is formed during fixing. If a post-washing step is employed, it is necessary to use a more concentrated solution of magnesium sulfate for fixing, for ; example, a 3 to 5% solution of magnesium sulfate would be acceptable. This washing step is preferably carried out using a conventional size press as previously described. The insol-uble magnesium humate remains on the paper and, after drying, is color fast and provides an acceptable paper for use in smoking articles. An acceptably intense brown color is obtained using the salt post-treatment of the presnet invention while maintaining a lowered carbon monoxide delivery.
The following examples are illustrative but are not intended to be limitive thereof.
Example 1 Experiments were conducted to compare different salts for use in fixing sodium humate stained papers. Conventional white ~' .
11193~i8 cigarette paper was stained with a sodium humate solution having a pH of 12.7. The stained paper was dried and separate pieces were treated with one of the following solutions: 5.0%
calcium chloride, 4.~% magnesium acetate, or 5.5% magnesium sulfate. Increased concentrations of fixing solutions were used to assure that some of the sodium ions would be displaced or exchanged by either magnesium or calcium ions. The humate-stained papers were fixed by immersion in the fixing solution using a conventional size press.
Eollowing the fixing step withthe above-named solutions, the stained and fixed papers were dried. Cigarettes containing a typical blend of tobacco were fabricated at 85 mm lengths and 120 mm lengths using the treated paper. All of the cigar-ettes had conventional cellulose acetate filters attached there-to.
The cigarettes were smo]~ed under controlled laborator~
conditions and the gas phase that passed through the filters was trapped and analyzed for carbon monoxide using known infra-red spectroscopy techniques. Cigarettes fabricated from paper that had not been treated by fixing with a calcium or magnesium salt served as controls. The results are tabulated in Table 1 below.
~!~,. Table 1 SALT POST-TREATMENT
Na Humate Salt P.C.* CO/cig.(mg.) pH 12.7 control 9.0 30.3 (A) 85 mm pH 12.7 5.0% CaC12 9.3 28.8 cigarettes pH 12.7 4.9% MgAc 9.0 31.0 pH 12.7 5.5% MgSO4 9.3 24.6 .
.~.. . . ,- , , ~: . , .,: "~
,, , i .
--3~B
g pH 12.7 control 12 31.4 (B) 120 mm pH 12.7 5.0% CaC12 13 29.3 cigarettes pH 12.7 4.9% MgAc 12 34.7 pH 12.7 5-5% MgSO4 13 22.7 *PC = puff count The data indicates that the papers treated with 5.5%
magnesium sulfate resulted in reduced carbon monoxide delivery when compared to the untreated control or to other salts known to render sodium humate insoluble on paper.
Example 2 Cigarette Paper was stained with sodium humate having a pH of 10Ø The paper was dried and fixed with one of the of the following solutions: 5% CaC12, 5.5% MgSO4, and 10% HCl.
Cigarettes were fabricated as in Example 1 and smoked under controlled laboratory conditions. The gas phase was trapped and analyzed according to the method previously disclosed.
The results are as follows:
Table 2 SALT POST-TREATMENT
85 mm Cigarettes Na Humate, pH 10 Salt PC* CO/Cigt. (mg) control - no salt 8.5 20.5 5% CaC12 9.8 25.0 5.5% MgSO 8.5 20.4 10% HCl 4 10.0 32.0 .
*PC = puff count Although the salts shown above are acceptable in render-ing the sodium humate insoluble, use of magnesium sulfate as :
..
, ~ .
~35~
the fixing agent results in a more acceptable carbon mon-oxide delivery rate.
Example 3 The sodium salt of sap brown, obtained from Abbey Chemi-cal Company, was dissolved in water to give a final concentrat-ion of 20% by weight. Conventional white cigarette paper was stained with the sap brown solution and dried. Separate pieces of the dried paper were fixed using either a 5~ sol~tion of calcium chloride or a 5.5% solution of magnesium sulfate.
Cigarettes (85mm) were fabricated using the prepared papers. Control cigarettes were prepared using stained but unfixed paper. Cellulose acetate filters were attached and the cigarettes were smoked and the gas phase analyzed as in Example 1. The results are tabulated in Table 3 below.
Table 3 Paper PC*CO/cigt. (mg) Control 8.6 26.8 CaCl -- fixed 8.8 23.6 ; MgSO4 -- fixed 9.7 21.9 *PC = puff count Example 4 Technical grade humic acid (Aldridge Chemical Company) was washed extensively with tap water until the supernatant uid became clear. Approximately 4% of the acid soluble material was removed. The humic acid was then treated with 1%
by weight sodium hydroxide. The pH of the mixture was 5Ø
Extensive washing resulted in a 20% weight loss, which repres-ented additional acid soluble materials.
. ~. : , , . ~, , , ~ 93~j~
The washed humic acid weighing 350 g was then treated with 21 g sodium hydroxide in three steps. At each step, the solution having a pH of 7-8 was centrifuged, and the supernat-ant liquid was decanted,dried at 50 C, and weighed. The separated sodium humate was combined with an additional wash of the insoluble residue and dried to yield about 160 g. This represented approximately 32% of the starting material.
The dried sodium humate was dissolved in water to give a final concentration of 15% (W/V). Following centrifugation to remove insolubles, the humate solution was 13.7% (W/V). The solution was coated on conventional cigarette paper by means of a size press. The paper was dried and post treated with a
-- 1, --POST-TREATMENT OF HUMIC ACID-DYED PAPER
Technical Field -; The invention relates to improved methods for staining papers suitable for use as wrappers for smoking articles wherein alkali humates are utilized. The humates are rendered insoluble on the paper using solutions of magnesium sulfate.
Background of the Prior Art The use of humic acid and fractions thereof as dyes is !,, well known. ("Recent Progress in the Chemistry of Natural and ' 10 Synthetic Coloring Matters," T.S. Gore et al. eds., Academic Press, N.Y. 1962, pps. 99-112.) Recently, a variety of cigar-ettes manufactured with brown paper wrappers have enjoyed increased popularity among smokers, and some of these cigarettes are fabricated using brown wrappers stained with humic acid.
; Processes for staining cigarette paper brown have included the ; use of dyes such as synthetic azo dyes, dyes produced from walnut shells, caramel, tannic acid and the like. However, .~ ~
the aforementioned stains or dyes are undesirable for a variety of reasons. First, the azo dyes, which contain large amounts of nitrogen, may produce undesirable pyrolysis products and, therefore, could be unsuitable for use in smoking articles.
Secondly, the amount of caramel required to produce the -~ ~k ..., - . .
-~: .
~1~93,~,8 desired intensity of brown color considerably inhibits the burn rate of the paper. The use of such stains as tannlc acid may provide the desired brown color; however, treatment of this type simultaneously reduces the porosity of the paper thereby also reducing the rate of combustion. In addition, adverse affects on the gas phase composition are also noted (see Austrian Patent 175,148).
By definition, humic acids are allomelanins found in soil, peat, and low-rank coal. They are generally alkali soluble and precipitated in the presence of acids. From a chemical standpoint, hu~ic acids generally consist of a mixture of complex macro-molecules characterized as having polymeric phenolic structures with the ability to chelate with metals.
In addition, humic acids have a strong base-binding power, and thision-exchange capability can be used advantageously in their use as dyes. There are many variations of humic acid depending upon differences in the plant remains from which they originate as well as the soil, climate, microflora, drainage, etc.
Humic acids, by nature, are intensely chocolate brown in color; and because of their natural origin, they are particular ly preferred over synthetic dyes as staining pigments for producing brown wrappers or papers for smoking products.
Generally, an a~lkaline solution is prepared by mixing the powdery humic acid with an alkali metal hydroxide, i.e., sodium hydroxide, to form a soluble humate salt. This solution is used to impregnate the paper on one or both sides, and this is followed by a fixing step, generally with salts such as ., , .,, ~, . .. .
.. , : : .
r~ -1~193~8 aluminum, calcium, iron, and the like. In essence, sodium ions are partially exchanged for alkaline earth or metal ions in the fixing process, thus leaving a water insoluble humate salt on the paper.
Hennig in Allgemeine Papier-Rundschau, No. 31:1027 (21 August 1967) describes methods for staining paper, and espec-ially paper suitable for cigarette wrappers, with Sap Brown ( also termed "nut stain" or humates) at about neutral pH.
The Sap Brown may be rendered insoluble on the paper by fixing with aluminum or iron sulfate. We have found that certain disadvantages are encountered when utilizing the foregoing method of Hennig. For instance, when aluminum sulfate is employed as the fixing agent, an undesirable masking of the rich brown color is observed.
Others have suggested various cations that are useful for precipitating humates, and they include chromium, magnesium, ; lead, copper, calcium, potassium, and the like. However, none have suggested that any one of the cations listed above would be suitable for use as a fixing agent when staining paper for ultimate use in smoking articles. Moreover, no suggestion has been made to indicate that one of these cations, when used as a fixing agent, might be preferable for use in smoking articles due to improved smoking characteristics, improved appearance, or lowered gas phase constituents on smoking.
Analy~ cal studies using humic acid-treated brown wrap-pers have indicated in some instances a tendency toward increased gas phase constituents. Various attempts have been made to reduce constituents, such as carbon monoxide, by ,:
~ ' ' ''' ,'', '' ' .' ~' . .
s~
using more efficient filter elements, by increasing the degree of ventilation in filters, or by increasing the poros-ity of the paper or wrapper, etc. However, none of these me1:hods have proven to be entirely satisfactory.
Brief Summary of the Invention This invention concerns the improvement of humic acid-treated paper or sheet material in which tobacco or any other smoking product is rolled for the fabrication of cigarettes, cigars, or the like.
The invention relates specifically to a process for treating humic acid-dyed brown paper suitable for use as wrappers for smoking articles wherein some of the products of pyrolysis are substantially reduced. In studies with cigar-ettesmade with commercially available humic acid-stained papers, it was observed that on pyrolysis the burning papers produced more carbon monoxide than conventional white cigarette wrappers. In an effort to identify the cause, experiments were designed to study a number of parameters related to dyeing with humic acid. The concentration and composition of humic acid was varied as well as the pH of the staining solution;
and in addition, a variety of cations (fixing agents) that render the humic acid insoluble and colorfast on the paper, were utilized in an attempt to reduce gas phase delivery.
From the results obtained, a total system for coating cigar-ette wrappe~s having reduced gas phase constituents has been ; developed an~ will be described in detail hereinbelow.
Thus, it is an object of this invention to provide a ; method for producing a humic acid-coated paper or smoking ' ' ! ~ .' . . ' ' , ' ' ~ . . ~, ' ' !
, ~ . ., ' ~ ' ~ . .' . . ' . . ' ":
' 1 ' ' ' . , ~
3~;8 wrapper whereby smoking articles produced from said paper can be materially improved.
It is a further object of this invention to provide methods and means that individually operate to provide a more desirable brown paper or wrapper from the standpoint of gas phase delivery whereby such ~as phase consitituents, such as carbon monoxide, are subtantially reduced.
It is yet a further object of this invention to provide a method for fixing humates on paper whereby a desirable color intensity is obtained with a concomitant reduction in gas phase constituents such as carbon monoxide.
Other objects and advantages will be discussed and des-cribed in detail hereinbelow.
Detailed Description of the Invention In the practice of the present invention, commercially available humic acid is suspended in water with stirring. The mixture is then centrifuged to recover the insoluble humic acid, and the acid-soluble materials are discarded. Experiment-ation indicates that the acid-soluble fraction is undesirable in that at certain concentrations there is a tendency towards gel formation, and, in addition~ this fraction does not apprec-iably improve color depth or intensity of the final staining solution.
The acid-insoluble humic acid fraction is generally dried, weighed, and then suspended in water. The pH of the suspension is adjusted with a base such as sodium, potassium, or ammonium hydroxide, with sodium hydroxide being preferred. The final pH of the staining solution should be between about 7 and 8 :, ~ ,. . ' . , ;
`\
93~8 for optimum results. There appears to be a tendency towards increased carbon monoxide delivery as the pH of the staining solution is increased over about a pH of 8. Stabilization of the pH of the solution may require about 8 to about 20 hours with continual stirring.
Just prior to the actual staining or dyeing of the paper, the alkaline humate solution may be centrifuged to remove any remaining insoluble materials. The insoluble materials are dried and weighed. The staining solution containing the alkali humate is adjusted by the addition of water to give a final concentrationofabout 12 to 16~ humate and preferably about 14~ humate by weight.
The actual staining process may be carried out utilizing a conventional size press wherein standard bobbins of cigarette paper are passed through a staining bath containing the alkali humate at a predetermined speed to insure that the desired amount of staining solution is retained on the paper. The paper may be stained on one or both sides depending on the desired effect to be achieved.
In an alternate approach, sodium humate is added to a slurry of purified cellulose pulp, and the slurry is used as a furnish in a conventional papermaking machineto produce a brown paper suitable for use in the fabrication of smoking products.
In a preferred embodiment of the present invention, the alkali humate is fixed on the paper by treatment with a dilute solution of magnesium sulfate. This salt post-treatment is preferably carried out after the paper has been stained and dried by conventional methods. Although calcium salts are well known fixing agents for alkali humates, we have found . . ..
, ..
, , ' , ' ', ~ ' .:
,: ,. ..
, : ::: ;
11~358 magnesium sulfate unexpectedly superior for use as a fixing agent when preparing paper for ultimate use in smoking articles.
Magnesium sulfate at a concentration of about l to 3%, and preferably about 2% by weight, provided consistently lower carbon monoxide delivery when compared to calcium chloride or magnesium acetate. Tests were conducted using aluminum sulfate as a fixing agent; and although carbon monoxide deliveries were acceptable, it was noted that at even the lowest concent-ration possible for fixing the alkali humate, the aluminum salt caused an unacceptable while film on the paper.
Following the fixing step the paper may be washed with water to remove excess magnesium sulfate or alkali sulfate salts, i.e., sodium sulfate, which is formed during fixing. If a post-washing step is employed, it is necessary to use a more concentrated solution of magnesium sulfate for fixing, for ; example, a 3 to 5% solution of magnesium sulfate would be acceptable. This washing step is preferably carried out using a conventional size press as previously described. The insol-uble magnesium humate remains on the paper and, after drying, is color fast and provides an acceptable paper for use in smoking articles. An acceptably intense brown color is obtained using the salt post-treatment of the presnet invention while maintaining a lowered carbon monoxide delivery.
The following examples are illustrative but are not intended to be limitive thereof.
Example 1 Experiments were conducted to compare different salts for use in fixing sodium humate stained papers. Conventional white ~' .
11193~i8 cigarette paper was stained with a sodium humate solution having a pH of 12.7. The stained paper was dried and separate pieces were treated with one of the following solutions: 5.0%
calcium chloride, 4.~% magnesium acetate, or 5.5% magnesium sulfate. Increased concentrations of fixing solutions were used to assure that some of the sodium ions would be displaced or exchanged by either magnesium or calcium ions. The humate-stained papers were fixed by immersion in the fixing solution using a conventional size press.
Eollowing the fixing step withthe above-named solutions, the stained and fixed papers were dried. Cigarettes containing a typical blend of tobacco were fabricated at 85 mm lengths and 120 mm lengths using the treated paper. All of the cigar-ettes had conventional cellulose acetate filters attached there-to.
The cigarettes were smo]~ed under controlled laborator~
conditions and the gas phase that passed through the filters was trapped and analyzed for carbon monoxide using known infra-red spectroscopy techniques. Cigarettes fabricated from paper that had not been treated by fixing with a calcium or magnesium salt served as controls. The results are tabulated in Table 1 below.
~!~,. Table 1 SALT POST-TREATMENT
Na Humate Salt P.C.* CO/cig.(mg.) pH 12.7 control 9.0 30.3 (A) 85 mm pH 12.7 5.0% CaC12 9.3 28.8 cigarettes pH 12.7 4.9% MgAc 9.0 31.0 pH 12.7 5.5% MgSO4 9.3 24.6 .
.~.. . . ,- , , ~: . , .,: "~
,, , i .
--3~B
g pH 12.7 control 12 31.4 (B) 120 mm pH 12.7 5.0% CaC12 13 29.3 cigarettes pH 12.7 4.9% MgAc 12 34.7 pH 12.7 5-5% MgSO4 13 22.7 *PC = puff count The data indicates that the papers treated with 5.5%
magnesium sulfate resulted in reduced carbon monoxide delivery when compared to the untreated control or to other salts known to render sodium humate insoluble on paper.
Example 2 Cigarette Paper was stained with sodium humate having a pH of 10Ø The paper was dried and fixed with one of the of the following solutions: 5% CaC12, 5.5% MgSO4, and 10% HCl.
Cigarettes were fabricated as in Example 1 and smoked under controlled laboratory conditions. The gas phase was trapped and analyzed according to the method previously disclosed.
The results are as follows:
Table 2 SALT POST-TREATMENT
85 mm Cigarettes Na Humate, pH 10 Salt PC* CO/Cigt. (mg) control - no salt 8.5 20.5 5% CaC12 9.8 25.0 5.5% MgSO 8.5 20.4 10% HCl 4 10.0 32.0 .
*PC = puff count Although the salts shown above are acceptable in render-ing the sodium humate insoluble, use of magnesium sulfate as :
..
, ~ .
~35~
the fixing agent results in a more acceptable carbon mon-oxide delivery rate.
Example 3 The sodium salt of sap brown, obtained from Abbey Chemi-cal Company, was dissolved in water to give a final concentrat-ion of 20% by weight. Conventional white cigarette paper was stained with the sap brown solution and dried. Separate pieces of the dried paper were fixed using either a 5~ sol~tion of calcium chloride or a 5.5% solution of magnesium sulfate.
Cigarettes (85mm) were fabricated using the prepared papers. Control cigarettes were prepared using stained but unfixed paper. Cellulose acetate filters were attached and the cigarettes were smoked and the gas phase analyzed as in Example 1. The results are tabulated in Table 3 below.
Table 3 Paper PC*CO/cigt. (mg) Control 8.6 26.8 CaCl -- fixed 8.8 23.6 ; MgSO4 -- fixed 9.7 21.9 *PC = puff count Example 4 Technical grade humic acid (Aldridge Chemical Company) was washed extensively with tap water until the supernatant uid became clear. Approximately 4% of the acid soluble material was removed. The humic acid was then treated with 1%
by weight sodium hydroxide. The pH of the mixture was 5Ø
Extensive washing resulted in a 20% weight loss, which repres-ented additional acid soluble materials.
. ~. : , , . ~, , , ~ 93~j~
The washed humic acid weighing 350 g was then treated with 21 g sodium hydroxide in three steps. At each step, the solution having a pH of 7-8 was centrifuged, and the supernat-ant liquid was decanted,dried at 50 C, and weighed. The separated sodium humate was combined with an additional wash of the insoluble residue and dried to yield about 160 g. This represented approximately 32% of the starting material.
The dried sodium humate was dissolved in water to give a final concentration of 15% (W/V). Following centrifugation to remove insolubles, the humate solution was 13.7% (W/V). The solution was coated on conventional cigarette paper by means of a size press. The paper was dried and post treated with a
2%(W/V) solution of magnesium sulfate. Unstained white cigar-ette paper was also treated in a similar manner with 2% magnes-ium sulfate.
Cigarettes, (120 mm) fabricated using a conventionalblend of tobaccos, were wrapped with the treated papers.
Cellulose acetate filters were attached to the cigarettes.
Cigarette A was wrapped with untreated white paper; Cigarette B
was unstained paper treated with magnesium sulfate; Cigarette C
was stained with humic acid; and Cigarette D was stained with humic acid and post-treated with magnesium sulfate.
The cigarettes were smoked under controlled laboratory conditions and analyzed as described in Example 1. The results are as follows:
; ' ' ~ ,, ~:' '''' ~
~ . .
' ' ~ ' ,' ~ ' `"
~l~a~s Table 4 PC* CO/cigt. (mg) CO/Puff Cigarette A
control 11.7 13.5 1.13 Cigarette B
control + MgS04 11.7 14.6 1.24 Cigarette C
humate stained 13.2 24.4 1.82 Cigarette D
humate + MgS04 13.2 22.6 1.66 *PC = puff count '`
.
.
.. . : ., , . . .: .-:
:. . . . .
: : , , : - . ~ ~ ~
- :' ~ ':- ' , ~
Cigarettes, (120 mm) fabricated using a conventionalblend of tobaccos, were wrapped with the treated papers.
Cellulose acetate filters were attached to the cigarettes.
Cigarette A was wrapped with untreated white paper; Cigarette B
was unstained paper treated with magnesium sulfate; Cigarette C
was stained with humic acid; and Cigarette D was stained with humic acid and post-treated with magnesium sulfate.
The cigarettes were smoked under controlled laboratory conditions and analyzed as described in Example 1. The results are as follows:
; ' ' ~ ,, ~:' '''' ~
~ . .
' ' ~ ' ,' ~ ' `"
~l~a~s Table 4 PC* CO/cigt. (mg) CO/Puff Cigarette A
control 11.7 13.5 1.13 Cigarette B
control + MgS04 11.7 14.6 1.24 Cigarette C
humate stained 13.2 24.4 1.82 Cigarette D
humate + MgS04 13.2 22.6 1.66 *PC = puff count '`
.
.
.. . : ., , . . .: .-:
:. . . . .
: : , , : - . ~ ~ ~
- :' ~ ':- ' , ~
Claims (5)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. In the method of treating paper suitable for use as wrappers for smoking articles wherein said paper is stained with an alkali humate solution having a pH of about 7 to 8, the improvement comprising fixing said stained paper with a solution of magnesium sulfate in an amount sufficient to render said humate insoluble and colorfast on the paper.
2. A method according to claim 1 wherein the solution of magnesium sulfate is 1% to about 5.5% by weight.
3. A method according to claim 1 wherein the alkali humate is sodium humate.
4. A method according to claim 1 wherein the humate solution is treated at a pH of from about 5 to about 7 to remove acid soluble material prior to staining the paper.
5. An improved paper suitable for use as wrappers for smok-ing articles where said paper is stained with an alkali humate solution and fixed with a solution of magnesium sulfate effect-ive to render said humate insoluble and colorfast on the paper.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US89912878A | 1978-04-24 | 1978-04-24 | |
| US899,128 | 1978-04-24 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1119358A true CA1119358A (en) | 1982-03-09 |
Family
ID=25410520
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000326263A Expired CA1119358A (en) | 1978-04-24 | 1979-04-24 | Post-treatment of humic acid-dyed paper |
Country Status (4)
| Country | Link |
|---|---|
| JP (1) | JPS54151608A (en) |
| CA (1) | CA1119358A (en) |
| DE (1) | DE2916032A1 (en) |
| FR (1) | FR2424359A1 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP2633121A1 (en) * | 2010-10-29 | 2013-09-04 | Hewlett-Packard Development Company, L.P. | Paper enhancement treatment with decreased calcium chloride |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| AU617351B2 (en) * | 1987-09-03 | 1991-11-28 | British-American Tobacco Company Limited | Improvements relating to smoking articles |
| US5094253A (en) * | 1990-01-05 | 1992-03-10 | Brown & Williamson Tobacco Corporation | Dye for coloring cigarette paper |
| US5101840A (en) * | 1990-08-13 | 1992-04-07 | Brown & Williamson Tobacco Corporation | Dye for cigarette wrapper paper and cigarette having dyed wrapper |
| EP1115469B1 (en) * | 1998-09-18 | 2003-10-15 | Franz-Dietrich Oeste | Fibrous products containing active substances, a method for the production thereof, and use of the same |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| NL108814C (en) * | 1955-02-26 |
-
1978
- 1978-10-25 JP JP13145978A patent/JPS54151608A/en active Pending
-
1979
- 1979-03-26 FR FR7907502A patent/FR2424359A1/en active Granted
- 1979-04-20 DE DE19792916032 patent/DE2916032A1/en not_active Withdrawn
- 1979-04-24 CA CA000326263A patent/CA1119358A/en not_active Expired
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP2633121A1 (en) * | 2010-10-29 | 2013-09-04 | Hewlett-Packard Development Company, L.P. | Paper enhancement treatment with decreased calcium chloride |
| EP2633121A4 (en) * | 2010-10-29 | 2014-01-08 | Hewlett Packard Development Co | Paper enhancement treatment with decreased calcium chloride |
| US9056515B2 (en) | 2010-10-29 | 2015-06-16 | Hewlett-Packard Development Company, L.P. | Paper enhancement treatment with decreased calcium chloride |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS54151608A (en) | 1979-11-29 |
| FR2424359B1 (en) | 1980-12-12 |
| DE2916032A1 (en) | 1979-10-31 |
| FR2424359A1 (en) | 1979-11-23 |
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