Classifications

• • A—HUMAN NECESSITIES
  • A24—TOBACCO; CIGARS; CIGARETTES; SIMULATED SMOKING DEVICES; SMOKERS' REQUISITES
  • A24D—CIGARS; CIGARETTES; TOBACCO SMOKE FILTERS; MOUTHPIECES FOR CIGARS OR CIGARETTES; MANUFACTURE OF TOBACCO SMOKE FILTERS OR MOUTHPIECES
  • A24D1/00—Cigars; Cigarettes
  • A24D1/02—Cigars; Cigarettes with special covers
  • A24D1/025—Cigars; Cigarettes with special covers the covers having material applied to defined areas, e.g. bands for reducing the ignition propensity
• • A—HUMAN NECESSITIES
  • A24—TOBACCO; CIGARS; CIGARETTES; SIMULATED SMOKING DEVICES; SMOKERS' REQUISITES
  • A24D—CIGARS; CIGARETTES; TOBACCO SMOKE FILTERS; MOUTHPIECES FOR CIGARS OR CIGARETTES; MANUFACTURE OF TOBACCO SMOKE FILTERS OR MOUTHPIECES
  • A24D1/00—Cigars; Cigarettes
  • A24D1/12—Cigars; Cigarettes with ash-retaining attachments, holders, or other equipment
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
  • C09K21/00—Fireproofing materials
  • C09K21/02—Inorganic materials
• • 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

Definitions

• This invention relates to a process for treating cigarette paper for the improvement of fire safety, for reducing, the offensiveness of the cigarette to non-smokers, and for reducing the health hazard to the smoker. It is particularly directed to the treatment of cigarette paper by processes which impart to the paper a coating containing silica (Si ⁇ 2) as the principal fire retardant.
• the treatment may be applied as a single step, or alternatively in two steps in which the first step is the impregnation of the cigarette wrapper with the silicate in a concentration such as not to soak the wrapper, and in which the other substances of the combination are applied in a separate step.
• My own U. S. patent 3,030,963, dated April 24, 1962 describes a cigarette in which dots or helical bands of silicate are applied to the exterior of the wrapper by means of a solution containing at least 14.57o Si ⁇ 2- The ; . dots or helical bands -form when they are sufficiently heated by the burning part of the cigarette, and produce a supporting surface underlying the cigarette, keeping the burning part raised above the surface on which the 5 cigarette is resting.
• This patent describes a cigarette which is not self-extinguishing.
• the principal object of this invention is to provid a cigarette having sufficient fire resistance to prevent fires from occurring when the lit cigarette is dropped upon a mattress, sofa or like piece of furniture, and 5 which, at the same time, has an acceptable appearance, a low manufacturing cost, and a taste unimpaired by the alkalinity of the silicate used in the treatment.
• Still another object of the invention is to increase the number of available puffs in a cigarette having a given q ⁇ antity of tobacco.
• Cigarettes produced in accordance with the Low patents have a uniform silicat coating, but are unable to prevent fires when dropped upon mattresses. Cigarettes made in accordance with Seaman likewise do not pass the mattress tests, primarily
• the coating described in Rubin is uniform, and potentially capable of preventing mattress ignition, but the cost of applying the coating is relatively high, and the taste of the smoke is impaired by the high
• the cigarette made in accordance with my patent 4,044,778 is capable of passing the mattress tests, but produces smoke having an alkaline taste, and the high concentration of silicate in the wrapper produces an appearance ' which in some cases is unacceptable.
• Cigarettes treated in accordance with my patent 4,146,040 produce smoke having an acceptable taste, but are costly to manufacture because of the need for distinct steps of applying silicate and pH-lowering material. None of these prior cigarettes produces a significantly reduced quantity of smoke between puffs.
• the coating is either too low in Si ⁇ 2 (as in Low) to produce adequate fire resistance, or, if sufficiently high (as in Rubin) the cost of manufacture is high, and the smoke is impaired by the alkalinity of the silicate.
• the cigarettes either do not pass the fire resistance test, or their taste and appearance are impaired, or, as in the case of my patent 4,146,040, a completely different process is involved, and the cost of manufacture is relatively high.
• the invention contemplates the treatment of cigarette paper by one or the other of two intrat processes.
• the first of the alternative processes comprises the steps of soaking at least part of the surface of the paper of the cigarette with an aqueous alkali metal silicate solution to impart a coating to the paper, allowing the coated paper to dry, and forming the paper into a cylinder to produce a cigarette wrapper, wherein.the Si0 2 concentration by weight in the coating, and the coated area of the surface in any selected three millimeter long section of the cylinder are within the boundaries of an area defined by straight lines joining the following points (the first of each pair of numbers being the percentage ratio of the coated area to the total area, and the second number being the percenta of SiOo in the silicate solution by weight): 100, 6; 100, 14-.5; 52, 16; 40, 16; 40, 12.2; 50, 10.5; and 90, 6.2.
• cigarette paper is treated by the sequential steps of soaking substantially the entire surface of the paper with an aqueous alkali metal silicate solution to impart a first coating, allowing the coated paper to dry, and a second step of soaking substantially the entire surface of the paper with an aqueous alkali metal silicate solution to produce a second coating.
• concentrations of Si ⁇ 2 by weight in the respective coating steps are within the boundaries of a triangle, the corners of which are defined by the following points (the first number of each pair being the percentage of Si0 2 by weight in the first coating step, and the second number of each pair being the percentage of SiO « by weight in the solution of the second coating step) : 6, 1.7; 6, 6; and 1.7, 6. - 7-
• Figure 1 is a schematic diagram of an apparatus 15 for applying a silicate coating to cigarette paper in accordance with one of the two alternative processes of the invention
• Figure 2 is a perspective view of a cigarette having a uniform silicate coating in accordance with 20 the invention.
• Figure 3 is a schematic diagram of an apparatus for applying two separate silicate coatings in accordance with an alternative method
• Figure 4 is a perspective view of a cigarette 25 having a partial silicate coating in accordance with the invention.
• Figure 5 is a rectangular plot depicting the interrelationship between the ranges of Si0 2 concentration and area coverage for the process involving a single * 30 coating step;
• Figure 6 is a rectangular plot depicting the interrelationship between the ranges of SiO ⁇ concentration in the respective steps of the process involving two sequential coating steps; -8- .
• Figure ⁇ 7 is a perspective view o another version of a cigarette having a partial silicate coating in accordance with the invention.
• Figure 8 is a rear perspective view of the 5 cigarette of Figure 7.
• the coater comprises a vessel 16 containing a liquid bath 18 consisteng of an aqueous solution of alkali metal silicate. Silicates are manufactured in various ratios
• alkali metal oxide e.g. a 2 0
• silica Si0 2
• a typical sodium silicate which can be used is type "0" silicate, manufactured by PQ Chemicals, Inc., of Valley Forge, Pennsylvania,
• Bath 18 when used to apply a uniform coating should have an SiO ⁇ concentration between about 6% and 14.5%, by weight.
• a roller 20 is provided at
• the roller is preferably driven so that its peripheral speed is near the linear speed of the paper.
• the roller can be made of any one of a wide variety of materials such ' 30 as porcelain or aluminum.
• the amount of silicate applie to the paper is determined in part by the extent to which the roller is wettable by the particular silicate - -
• the roller speed is adjusted ' so that the quantity of solution applied to the paper is not appreciably more than is necessary to 0 moisten the opposite side of the paper.
• Dryer 16 which is shown diagrammatically, can be any sort of dryer capable of removing moisture from the paper. Preferably, however, a hot air dryer is used.
• the roll 12 of cigarette paper can be only as 5 wide axially as the length of a typical cigarette, it is preferably at least several feet long for efficiency in treatment of the paper.
• the paper is then slit to the desired " length following drying.
• a typical cigarette, the paper of which is treated 0 by the apparatus of Figure 1, is shown in Figure 2.
• This cigarette comprises a charge 22 of tobacco, a filter covering .24, and a cylinder 26 of treated cigarette paper.
• the silicate coating can be either on the inside, i.e. next to the tobacco, or on the outside, or both on the 5 inside and outside if suitable modifications are made in the treating apparatus.
• the coating step carried out in accordance with Figure 1 stiffens the cigarette paper somewhat, but does not otherwise appreciably alter its physical appearance.
• the burning characteristics of 0 the cigarette, however, are materially changed.
• the cigarette does pass the fire resistance test, and at the same time is capable of smoldering for at least one minute, thereby assuring satisfactory smoking.
• the apparatus of Figure 1 can be modified, by incorporating axially aligned grooves in the outer surfac of roller 20, to produce a cigarette paper having only part of its outer surface coated with silicate.
• Figure 4 It comprises a charge 54 of tobacco, a filter covering 56, and a cylinder of cigarette paper 58 having multiple- longitudinal stripes 60 extending along its length.
• the wetting characteristics of the roller are preferably .chosen so that the quantity of silicate solution applied to the paper along the longitudinal stripes is just sufficient to soak the paper.
• the wetting characteristics of the roller are determined largely by the material from which the roller is made.
• the peripheral speed of the roller in the case of a partial coating, of course, should be equivalent to the linear speed of the paper.
• a minimum number of lines should be applied, and I prefer to use either one or two lines.
• a typical cigarette having two lines of silicate coating 62 and 64 is shown in Figure 7 and 8.
• the silicate coating covers an area of between 40 and 100 of the total area of the section.
• the interrelationship between the area of coverage and the silica concentration is depicted in Figure 5.
• Figure 5 where the cigarette paper is fully coated, the silica
• O concentration ranges from about 6% to 14.5%.
• the apparatus of Figure 3 is used to carry out a coating process involvingtwo coating steps.
• Paper 28 is fed from roll 30 over a first coater 32, through a
• the first coater comprises a vessel 40 containing a silicate bath 42, which is applied by means
• the second coater 36 comprises a vessel 46 containing a silicate bath 48, which is applied by means of a roller 50.
• the apparatus of Figure 3 produces a cigarette paper having a uniform silicate coating.
• the concentrations of the respective baths 42 and 48 are interrelated, as shown in Figure 6, so that, if the 5 silica concentration in the first step is 6%,, the silica concentration in the second step can range from about 1.7 to about 6%. As the silica concentration in the first step decreases, however, the minimum silica concentration in the second step increases so that the
• Cigarettes manufactured in accordance with either of the two methods just described, are capable of satisfying a fire safety test derived from the United States Government's "Federal Flammability Standards for Mattresses" set forth in the Federal Register, Volume 37,
• the test is carried out as follows. The cigarette is lit and permitted to smolder for one minute. It is then placed on the mattress until it self-extinguishes, or until it is fully consumed without igniting the mattress. After
• the cigarette ignites the mattress at any time during the test, it fails the test. If, however, the cigarette is either fully consumed without igniting the mattress, or self-extinguishes two or more times, and does not ignite the mattress, it is considered to pass the fire test.
• the cigarette must also be capable of smoldering for a full minute between puffs. That is, it must not self-extinguish, when held in a horizontal position, and smoked at the rate of one puff per minute.
• Cigarettes prepared in accordance with the invention satisfy both of the above requirements, and in. addition exhibit satisfactory taste and smoking characteristics.
• Smoking characteristics are considered satisfactory when the volume and density of the smoke produced by the treated cigarette are substantially the same as the volume and density from the smoke of an untreated cigarette during puffing, but between puffs, the smoke is reduced to almost negligible quantities.
• the reduction of the quantity of smoke produced between puffs makes the cigarette less objectionable to non-smokers and less hazardous to the health of the smoker. At the same time, it increases the number of puffs available from a given quantity of tobacco, thereby making the cigarette less expensive to produce.
• Cigarettes made from paper treated in accordance with the invention exhibit superior ash retention, which contributes to safety by reducing the likelihood of skin contact burns and fires caused by hot ashes falling onto clothing and upholstery.
• the superior ash retention of cigarettes made in accordance with this invention also contributes to the cleanliness of carpets, clothing and furniture.
• the process of the invention is applicable to conventional cigarettes of various types, including the so-called “little cigars", and to cigarettes having vari cross-sectional shapes other than circular. It is also applicable to cigarettes having circumferences differing from the conventional 25 mm. circumference, and to cigarettes containing tobacco substitutes either along with tobacco or instead of tobacco.

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• Chemical & Material Sciences (AREA)
• Inorganic Chemistry (AREA)
• Engineering & Computer Science (AREA)
• Materials Engineering (AREA)
• Organic Chemistry (AREA)
• Paper (AREA)
• Cigarettes, Filters, And Manufacturing Of Filters (AREA)

Applications Claiming Priority (1)

Publications (1)

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Family Applications (1)

Country Status (2)

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Family Cites Families (9)

• 1980
  • 1980-02-07 WO PCT/US1980/000120 patent/WO1981002243A1/en unknown
  • 1980-02-07 EP EP19800900992 patent/EP0045302A1/de not_active Withdrawn

Non-Patent Citations (1)

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