DE2039406A1 - Filter material for tobacco smoke - Google Patents

Description

PATENTANWÄLTE β MÜNCHEN 2. HIUBUESTRASSE 2O

• Dr. Berg Dipl.-Ing. Stapf, 8 Munich 2. Hllbl «slro6e 20 ·

Your reference Our reference 18 878 Date

L> 7. Aug 1970

Attorney «tktt 19 878 Britieh-Aaerican Tobaoee Coapany Liaited London, S.W.l / ENGLAND Filter material for tobacco smoke

The "charge concerns" in Yerbeaa tea filter material for Tobacco smoke and the procedure for "a division"

The aittele Herköaalleber cigarette afliter achievable displacement the amount of tar given off becomes the necessity to have a auereiebeadea pressure drop across the cigarette with simultaneous Preservation of the weeeatliohea Sigeneohaften de «Baaoha aa erhaltea,

10981171344

limited. Both inside and outside the tobacco processing industry Industry is constantly looking for more effective cigarette filters sought.

Previously · Attempts to increase the effectiveness of cigarette filters Using porous material therein has had limited success as such material is found to be acceptable in preserving Pressure drop did not prove very effective in removing tar. Such known filter material includes, for example bound to self-supporting rod form · or in Fiber or fabric material embedded granular activated «charcoal, activated · clay, silica gel and various · synthetic resins as granules ·.

An important ·· object of the invention is to provide an improved filter material for cigarette filters, by means of which a Eauoh-air mixture mat at an acceptable pressure drop of less than 88, · water column and can be filtered with high efficiency, dal at least 50% SE of the in the tar contained in the mixture can be removed without affecting the tobacco smack.

The filter material according to the invention should be low enough Costs to be produced, so compared to conventional filter material is competitive.

These and other inexpensive ligands and distributions are made in accordance with the invention d «raw the creation of from pore's« «fabric with surface» swisoaea 0.5 umd 4.0 ■ * / «» · »» · * peresity lwisohem

11/13 4

30 and βθ % and an average pore diameter between 2 «ad 10 / <- a existing filter particles. Porous material exhibiting the desired physical properties can have cored or fibrous fibers and can be of natural origin, such as, for example, melt-flow calcined matome earth, or synthetically produced, such as, for example, porous polyethylene, acetateselluloae or polystyrene-acrylonitrile.

The invention also relates to novel methods of manufacture polymeric resins in the form of τοη porous granules or fiber particles with the above physical properties and a cigarette filter using such porous Materials · Further details and features of the invention result from the following description τοη exemplary embodiments based on the drawing. In this one is:

Fig. 1 is a schematic partial view shown in section one with one the porous material according to the invention in ■ Granulate form between layers of conventional fiber material filter containing cigarette,

Fig. 2 is a schematic sectional view of the invention Filter material in granulate form, the individual particles are then separated from each other at certain points are,

1 0 S 8 1 1/1 3 h U

Fig. 3 is a view corresponding to FIG. 2, with the connection However, a binding agent is used between the individual particles,

Fig. 4 is a schematic oblique view of the invention porous material in its fibrous form and

FIG. 5 is a view corresponding to FIG. 1 of one of the

proper porous material in fibrous form along with

fc cigarettes using a common mouthpiece

filters.

The cigarette 10 shown in Fig. 1 is one of the invention Filter 12 containing porous material in granular form. You cigarette has a tobacco 16 in a paper tube 18 containing tobacco rod 14 on. On the paper tube 18 the filter 12 is attached. This consists of three sections, namely a tobacco side 20, a central part 22 and

bucket lip side 24, which are arranged together in a casing 26 are · an outer, for example made of paper or cork produced envelope 28 covers the entire filter and extends to some extent over the boundary line between Filter and tobacco rod out.

The sections forming the tobacco and lip sides of the filter 12 are made of conventional fiber material, for example Acetate cell reading fiber contained in a paper tube 27, produced These two sections are some distance apart.

1 0 S .'Π 1/1 3 /; /,

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arranged on the other and form a chamber for receiving the thus the central portion forming porous material 30 * The lip and tobacco sides 24 and 20 should each be at least 5 am long to complete the granulate filling more accurately η and To enable the cigarette to be held comfortably, the length of the granulate filling should be reduced by at least 10% the total length of the filter.

The porous granulate 30 can be of natural or artificial origin. In both cases, however, in terms of physical properties, ea has a surface area of about 0.5 to about 5.0 m / g, a porosity τοη about 30 to 90 $ and an average pore diameter τοη about 2 to 10 ^ m. The surface is preferably

4th

each between about 1 and 3 m / g. Alas the porosity of the material iat the proportion of the cavities contained in a valley Total volume denotes aa particle. The approximate relationship iwiaehen pore volume, perimeter and total surface iat by means of the following equation shown, weave the pores zylindriaeh assumed aind:

Per> »τ · Imme» (im a »/ g) -

- 0.21 Porendurohmeaor

eeaamtoberlfähe (im om / g) (i _{n ce} )

Ea was also found that the size of the individual parts The pressure drop over the finished filter is partially ventilated. Sa iat a greater pressure drop with decreasing particle size obtainable. In this way, in a filter corresponding to the Torah, Beaehreibuag rerweadete filter particles with a sieve

10 9 8 11/13 /, ', - - β -

• Pass in a mesh size of 0.841 mm (20 mesh) and on one 0.149 µm (100 mesh) sieve retained, one corresponding to the common fibrous filter substance Pressure drop of approximately 76.2 mm water column across the filter. Preferably however, particles on the order of between about 0.595 and 0.177 mm (30 to 80 mesh) are used. Form the particle does not appear to be critical, although round or spherical particles give somewhat better results were than with other forms. The filter effectiveness and the tensile resistance of the granulate filter filling are a matter of course also dependent on the storage density of the particles in the filling. To achieve a pressure drop across the filter of approximately 76.2 mm Water column, this should be between 0.06 and 0.40 g / cm and preferably between 0.09 and 0.30 g / cm. Such a density of storage can be achieved by introducing the particles in free fall into the chamber, with the individual particles without further Compression comes into contact with the neighboring particles

A preferred porous material of natural origin for use in the filter according to the invention is in the melt flow Calcined diatomaceous earth that meets the specified requirements. Various synthetic fabrics can be used, such as peruse polyolefins, for example polyethylene, polypropylene, eder perous acetate cellulose, porous polystyrene-acrylonitrile or Such ^ results obtained so far indicate that it is porous Ethyl cellulose is the most suitable synthetic material.

1 0 9 8 1 1/1 3 U

The particles held in section 22 of filter 12 can be optionally connected to each other. In Figs. 2 and 3 are two types of interconnected filter material are shown. In the embodiment according to FIG. 2, porous granulate particles 32 are welded together without a binder. There are those porous particles made of the above-mentioned plastic resins shaped, which become sticky on the surface when heated in a common machine for the manufacture of filters and flow together at random points of contact 34, se that the use of binders to form a self-supporting Strand is not required "

The parts 36 of the porous filter material of the embodiment 3 are connected to one another by a binding agent 38. Any suitable adhesive can be used for this purpose, for example the adhesives disclosed in U.S. Patent 3,363,544. Any currently used as a binder is also used thermoplastic resin usable. These resins can be soluble in water or melted or by the application of heat are softened «In Figs. 2 and 3 the size of the peres is each Particles reproduced in supernatural size to illustrate the representation.

Fig. 5 shows another embodiment made of a porous material 44 in fibrous or spotty form Cigarette 40 provided with a filter 42 according to the invention. The filter 4B has two parts, namely one connected to the tobacco rod 14, formed from the perous material 44 front part 43 and a Muadstttekteil 45. The mouthpiece part 45 contains in a Böhrehen 10 9 8 11/13 4 4

47 common fibrous filter material such as acetate cellulose fibers, as already described above. The porous material 44 in the front part 43 of the filter has the same physical Properties like the granulated embodiment of the material according to the invention described above and can consist of the same material, In addition, the length of the individual flakes should be at least 0.5 mm and move between 0.5 and 20 mm. The width of the individual flakes should be between 0.25 and 2 mm, and their thickness between 0.025 and 0.25 mm. Satisfactory results have been obtained with porous acetate cellulose flakes having an average thickness of 0.03 mm and an average width of 1.0 mm. Again, the cross-sectional shape of the individual flakes is not critical. Slightly more favorable results were, however, with ribbon-shaped flakes compared to flakes or fibers of round, oval or square cross-section achieved. A single flake 46 of the fibrous or flaky material 44 is shown in FIG. 4.

Without restricting the invention to theoretical considerations, it is believed that that from the tobacco rod to the lip side of the filter flowing smoke-air mixture through the individual die Filter filling forming particles or flakes through and around them and that the improved filter effect on deposition within the pores and absorption on the surface of the particles.

The "porous" material according to the invention can be made of thermoplastic Resins are made by incorporating starch particles in the resin

are closed and swelled therein, whereupon the Starch by enzymatic and / or chemical hydrolysis or by dissolving by boiling in water with subsequent draining the solution is removed. The resulting porous material has the desired physical properties in terms of Surface area and mean pore diameter and can then using devices commonly used in the tobacco processing industry to manufacture filters will.

In order to better understand the method of manufacturing the synthetic porous material having the properties described above, some examples are described below. In each of the examples a starch was used which when swelled gave a pore size of 2 to 10 / ^. Since the swelling ratio of the starch types used was around 100 % , the original grain size of the starch was 1 to 6 μm. The enzyme used in the examples described below was a bacterial-based alpha-amylase sold under the trade name Tenase by Miles Laboratories. The "parts" given in the examples are parts by weight.

Example 1 - Porous Pelyäthylagranulat

A mixture of 100 parts of a polyethylene resin sold by USI Chemicals under the name MN 710-20 (Melting index 22 / g / 10 min according to ASTMD 1238-Ö2T; Vioat bending temperature 85 ° C according to ASTMD 152Ö-GST; Crystalline melting point 1O7 ° C), 100 parts of rice starch and 2 parts of a lubricant, for example under the name Armid duroh the company Armor 1 Ü 'j -M 1/1 3 / /,

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Products, Inc ;, sold 9-octadecanamide was mixed for 30 minutes in an evacuated rotating jar. The vessel was heated in a 120 ° C oil bath for 30 minutes to granulate the mixture. The progress of the granulation was determined by visual observation and tactile feeling. The granulated material was sieved off and 50 parts with a grain size between 0.420 and ½.297 mn (40 - SO mesh) were obtained for further processing. The amount obtained was dissolved in 250 parts of a Eniym activation solution (0.01 molar calcium ion; pH 7.2; 0.02 molar sodium ion) and suspended with stirring for 30 min at 95 - 98 ⁰ C and warmed then 88 ° C cooled. OJ05 parts of enzyme were added and allowed to act for 40 minutes at 85 ° C. to solubilize the starch. The grains were then washed, dried and sorted again. During the swelling of the starch, with a view to the desired porosity of 30 to 90 %, the temperature was not allowed to drop below 80 C or rise above 130 C, since at this temperature the porosity would be destroyed by the collapse of the walls formed from the polymer used.

Example 2 - Porous polyethylene granules

A mixture of Polyäthylenhari (melt index 2% / 10 min according to ASTMD 1238-62T; Vicat softening temperature 99 ° C according to ASTMD 1520-58Tj crystal melting point 112 ° C) and Keietärke in the ratio 1: 1 was in the same way as in Example 1, however granulated at an oil bath temperature of 140.degree. The granules were ground wet and then dried and sieved, 50 parts of the granules having a grain size of between 0.420 and 0.297 mm (40-50 mesh) being obtained. The granulate was divided into 300 parts of 1 0 S1 H 1 1/1 3. '» U

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a saturated sodium chloride solution of 36 parts of NaCl 100 parts of water and suspended at a temperature of 107 C. allowed to swell under atmospheric pressure. After 20 minutes at this temperature, the salt solution was drained off, the granules Washed in fresh water and connect! in 250 parts of the Suspended 0.05 part of enzyme-containing enzyme activating solution. The solubilization of the starch required 40 min at 86 C, whereupon the granules are washed in hot water, dried and was re-sorted

Example 3 - Porous' polyethylene granules

25 parts of a polyethylene granulate according to Example 1 with a 50 mesh grain size was mixed with 100 parts corn starch for half an hour · the temperature of the mixture was then increased to 92 ° C. for 2 h and held at this value for 2 1/4 h. After that time it became Including the starch particles in the polyethylene as completed accepted. 400 parts of water were added to the mixture and the mixture was heated to 95 ° C. for one hour. More water was added to bring the total volume of the mixture to a value corresponding to β0Ό parts of water. The mixture was heated to 80 ° C allowed to cool and adjusted to the enzyme activating conditions. 0.25 part of enzyme was added, and then found the starch to be solubilized during one hour at 85 ° C instead of. The material was then washed over a 0.250 mm (60 mesh) sieve in a vacuum oven dried at tree temperature and then sieved.

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1 0 i! 8 1 1/1? . ', /,

Example 4 - Porous Acetate Cellulose Granules

A dough was prepared by dissolving 100 parts of acetate cellulose in powder form in 400 parts of acetone, into which 400 parts of corn starch were mixed. The material was placed in a vacuum dryer and the acetone was suctioned off. The dried dough was ground through a 0.841 mm (20 mesh) sieve and then sieved. 50 parts of the material with grain sizes between 0.420 and 0.297 mm (40-50 mesh) were suspended in 400 parts of a 0.01 molar calcium solution, the pH of which was adjusted to 6.8 with sodium hydroxide, and the sodium ion concentration of the slurry adjusted to 0.02 by means of sodium chloride. The mixture was heated at 1 kgf / cm (15 psi) pressure for about 30 minutes and then cooled to 85 ° C. Then 0.08 part of enzyme was added. Heating the mixture under pressure, as noted above, was necessary to achieve the required porosity in the final product. When exposed to heat without pressure, the porosity of the end product was below the minimum of 30 % and the tar filtering efficiency fell below 50 Jt. The solubility of the starch required 40 minutes at 85-88 ° C in the current example. The granules were drained, washed with hot water over a sieve with a mesh size of 0.149 mm (100 mesh), dried in vacuo and re-sieved.

Example 5 - Porous Acetate Cellless Granules

A dough was prepared by dissolving 100 parts of powdered acetate cellulose in 400 parts of acetone with 10 parts of triacetin. 29 parts of sodium chloride were in 80 parts of warm water

1 OL ';! 11/1;? ! ■ .r _1Q

- IS - *

• dissolved and slowly added to the dough. Subsequently were 300 parts of cornstarch mixed into the dough. The material was treated in the same way as in Example 4.

Example 6 - Porous Acetate Cellulose Granules

By dissolving 4 parts of acetate cellulose in 16 parts of acetone a dough was made. A solution of 1.19 parts of sodium chloride in 3.19 parts of water was slowly added and mixed with the batter. This was followed by 12 parts of corn starch added and the mixture agitated for one hour. The dough

was dried in a medium steam at 2 kgf / cm (30 psi) heated roller system with a roller spacing of 0.3048 mm (12 mil). The dried dough was then wet milled and then milled through a mesh screen 0.841 mm (20 mesh) passed. Then it was made up to 150 parts with Wasaer. The slurry was adjusted to 0.02 molar Ca ++ and pH 6.8 to 7.2 and then ^{heated at 2.7 kp / om 2} (40 psi) for 30 minutes. The slurry was connected! Allowed to cool to about 90 ° C., whereupon 0.04 part of enzyme was added and the mixture was stirred in mechanically for 40-0 minutes. The granulate was then drained, washed with hot water and dried in vacuo. The dried granulate was sieved, with the part with a size of between 0.595 and 0.177 mm (80-80 aesh) being retained for evaluation.

■ •! Game 7 - Poresos Ae »tatzell» l «a« -Qranmlat

By dissolving 1 part of acetatollulose in powder form in 54 Great aeetes were made in batter. Then 40

1 0 ίJ H 1 1/1 3 4 U

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Parts of corn starch slowly mixed in so that a homogeneous mixture was formed. The batter mix was spread on polyethylene sheet to remove the acetone by simple evaporation. Most of the material was sufficiently dry after 4 to δ hours and was now broken by hand into flakes of about 25 with 50 μs in diameter and then in a first pass through a sieve with a mesh size of 1.190 mm (16 mesh) and in one second pass through a sieve with a mesh size of 0,420 mm (40 mesh) wet ground. The starch / cellulose particles were allowed to settle and the excess water was drained off. 200 parts of water were then added to form a slurry. The slurry was stirred thoroughly for a few minutes and then adjusted for enzymatic solubilization. Sufficient calcium chloride was added to achieve a 0.01 molar calcium ion concentration. The hydrogen ion concentration was brought to pH 7 by adding 50 ml of a bucket of 10% sodium hydroxide solution. The sodium ion concentration was then adjusted to 0.02 molar by adding sodium chloride. The slurry was warmed to QS C over 40 min and then cooled ^{to SO 0 C.} The enzyme was then added to the mixture, whereupon the silting of the starch was visually perceptible within a few minutes. The ensemble treatment was continued at SI ⁰ C for 40-45 minutes. Stirring was then carried out and the granulate was allowed to settle and the bottom - most of the liquid was removed. Finally, the granules were washed and dried in a vacuum oven at room temperature.

109811 / 134Λ

Example 8 - Porous »Polytyrene Acrylonitrile

40 parts of rice starch were added to a stirred solution of 20 parts of styrene / acrylonitrile mixed polymer in 280 parts of dimethylformamide. The suspension was stirred for 15 minutes and then poured into 1900 parts of methanol with vigorous stirring to precipitate the copolymer. After stirring for a further 10 min, the methanol suspension was passed through a suction filter. The filtered solids were dried in vacuo (−0.10 mm Hg) at room temperature for 20 h _{to remove CH 0 OH and dimethylformamide.}

A solution of 0.40 part of CaCl2 in 360 parts of distilled water was adjusted to a pH of 6.8-7.0 by adding a few drops of a 10/6 NaOH solution. To achieve a sodium ion concentration of 0.02 0.41 parts of sodium chloride were added molar. The solution was placed in a blender and the dry starch-film mixture added. The suspension was stirred for about 5 minutes in order to break larger lumps of the starch-polymer mixture and was then transferred to a vessel in which it was heated ^{to 90 ° C. with stirring to swell the starch.} At this point an additional 100 parts of distilled water had to be added to enable effective stirring. About 0.08 parts of enzyme solution were subsequently added to the suspension and then this for 16 min at 75 - 85 ⁰ C stirred, zn promote the enzymatic hydrolysis of starch. The hot suspension was passed through a suction filter and the solids washed in warm water. After further washing and drying in vacuo (0.10 mm Hg) at 25 ° C

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"** ης 20394Ü6

The porous polymer was sorted according to the desired particle size over a period of 20 hours.

The sieve axis widths used in the description refer to Referring to the USA Standard Sieve Table of the US Bureau of Standards Clay 1919.

Example 9 - Acetate Celluloae Porous Fiber Flake Material

The manufacture of speckled porous acetate cellulose occurs in the same way as that of granules. The difference is the addition of a plasticizer to the doughy starting material, im reduced roller spacing to achieve thinner layers of the dried dough and in cutting the dried dough Flake or strip shape instead of wet grinding before further processing, the addition of plasticizer is for cutting indispensable, otherwise the material will be too brittle to cut.

Two parts of waste acetate cellulose fiber were dissolved in a solution of 8 parts of acetone and a little less than 1/2 part of a plasticizer composed of β parts of triethylene glycol acetate and 5 parts of polyethylene glycol with a molecular weight of 600. The amount of softener was 20 % of the weight of the acetate cellulose. The resulting dough was stirred for 30-40 minutes. A salt solution containing 15/8 part water and 5/8 part sodium chloride was slowly mixed into the dough and then 6 parts corn starch were added. The mixture was agitated for 60 minutes and then using the hot rolling system with a roller

1 0 S ίΠ 1/1 Ι A / ■, - 17 -

distance of 0.0762 mm (3 nil) to dry »sheet material rolled. The dough dried in this way was cut with about 40 cuts to 25 ₁ 4 mm in ribbon format and suspended in 150 parts of water. The suspension was placed in a pressure cooker to swell the starch for 30 minutes at 2.7 kgf / cm (40 psi). The material was then allowed to cool to below 100 ° C., removed from the digester, adjusted to enzyme-activating conditions (0.01 molar Ca **; pH 7.0; 0.02 molar Na ⁺ ), and 0.08 part of enzyme was added. Solubilization of the starch was continued with occasional hand stirring for 60 minutes. The end product had a residual starch content of 12 %. The licked aerosol cellulose was sieved off, washed with hot water, drained, spread out on 90 × 90 cm sheet metal and dried in the oven.

The cut acetate cellulose then consisted of relatively long strands of about 76 to 127 mm in length, which then went through a crusher. The flake material was then sorted by means of a shaking sorting device, wherein all material passing a mesh size of 2, S3 mm (7 mesh) and retained material at a mesh size of 0,297 mm (52 mesh) was collected.

Bciipiol IQ - FerMie «Aeetatiellnlese-Fastrfleokeamaterial

! mitigates Parts of the Aeetatsellmlese were in one reading voaSOO part of Aeetea. uxd 20 parts of a Weiehmachera from · parts Triithyltaglykeleieietat "ad I parts" Pelyathylan with eiaem Mel «k« largewieat t00 hung up. The crowd «e« Weiohmaoktrs e.t-

QfHGlNAL 1 0 9 8 1 1/1 3 A 4

■ pruteh 20 $ de "weight of Aoetatzelluloae * The dough was 30 - stirred for 40 minutes laag, toi" the entire Acetatzelluloae dissolved. A bath of salt solution containing 80 parts of sodium chloride and 90 parts of water at a temperature of about 80 C was added to the batter, and then 300 parts of shark were mixed in with it. The mixture obtained was during sth. Diner hour "rolled aneehlieBead using the hot roller aayatesus from example 9 to a sheet material auagewaisit" Here the rollers & bstand is chosen so that the thickness

trockeiaeia 31afctnat "ri * .le 80 - 8S fi dariirdfts Ftrtiferzeugnia ictk" amounts.

In the " trodktne Bl" tt "at" rial Turtle Mater a use of the titoa Tan fabak in Stmifea Y "Tw <exidet" n similar Fallmeaaer-Schii "idrorrichtüixg with" about 2i cuts to 25.4 "a in stripes"& · Faulty * _t floekiges t> dtr etabföriiige 'material was "aneehlieficitd van u®m gec ^ hnitteneii material screened. A Qe * ieatst «il dta getebaittentB Materinla was in 4 parts of a 0 _t 02 month. C% l «iuBekloiridli) siä5ig» β »ρ · * # art and the received ·

Iur «it £ ueafs Tea Sodium Hydroxiel 'fei« su one

τβιι 0.02 to a pH value of 7 ttl.It _# Di "Aitfsetliliüiimng was in the <|« ®llara of strength and sum Avf reuen ά% τ FerfKWftnimngeii during 9 % in a pressure vessel tt # i 1 kp / «N ^S (IS psi) to ÜO °, and anashliefiend amf 88 ΙΚ ^Φ € tiitffikiiiit ,, 0« Hf ABfitohllmtuBif b «r« ita Torher «he Enayaeittgeatvllt was, was 0 _} 063 parts kenaentrier '

(der Milea Laberat «riea) -I <8smaf s« k LHm-

«He EtKrk # smgeaetiit« Zua Itealionaaehen the strength

11/13 4 4

BATH ORIGINAL

With occasional stirring, the temperature was between 88 and Held at 92 ° C. The solubility of the starch was after 50 to 60 min essentially closed. Solubles were drained from the cut material, this in hot tap water washed extensively and left to dry in the open air. For disassembling clay clumped material and longer The dry, porous acetate cellulose was loosened and sieved in a stream of air. After selective sieving of the dry material, the mean dimensions of the flakes were 0.88 mm in width and 0.0305 mm thick.

As mentioned above, in the manufacture of porous cellulose acetate, it is essential to heat the cellulose acetate dough under pressure to allow the starch to swell sufficiently to produce the required porosity in the end product, whether in the form of granules or flakes. On heating the Acetatzellulose at atmospheric pressure, the strength swelled by only 10 Jf, in contrast to the 100 $ swelling in the foregoing examples, wherein a material originated, which would remove at inclusion in a cigarette filter 35 i "of the tar. Examples of porous material with the desired surface area and porosity and with the desired forum diameter which, when used in a cigarette filter made up of two or three sections, filter out at least 50% of the tar with a pressure drop of less than 88.0 mm of water column are in the Table 1 listed. The results obtained with filters using such material are shown in Table 2, the comparative cigarette being one

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10 9 8 11/13 4 4

Acetate filters of the same length and with the same pressure drop as the test material. In the information on the structure of the filter In Table 2, the designation "7mm 3.3Y / 44,000 CA" means a 7-aun long section of Acetatzelluloeefaeern of Y-shaped cross-section denier for a total of 44,000 denier.

Table 1 - Physical properties of the filter material (horizontal) 1, surface (»/ g)

fe 2nd pore volume (ce / g)

3. cement pore diameter (/ ^ m)

4, porosity (f> cavity)

8. Apparent bulk density (g / cm) (perpendicular) 1. Calcined diatomaceous earth

2. Polyethylene granulate (example 1)

3. Polyethylene granulate (example 2)

4. Acetate cellulose (Example 4)

5. Aoetate cellulose (Example 7)

β. Styrene / acrylonitrile (example 8) 7. Acetate cellulose (example θ)

Table 2 - Filter performance Description of the filter

(horizontal) 1. Material

2nd lip side

3. kitte1 «ttick

4. Tobacco "eit"

5. Pressure drop (in mm of water size)

6. Tar (in ag per cigarette) Trial comparison

7. Tar removal efficiency (ji) Try comparison

(vertical) 1. Melt-flow calcined diatovene earth (0.354 /

0.280 β »(45/60 ■ · ■)),

2. Polyethylene example 1

3. Polyethylene example 2

4. Polyethylene Example 3

5. Aoetate cellulose Example 4

6. Acetate cellulose example 5

7. Acetate cellulose Example 6

8. Acetate cellulose Example 7

9 Polystyrene / Acrylonitrile Example 8

10. Aostatzelluloss example t

11. Acetate cellulose example

The columns su tar per cigarette, g, trial and comparison seem to be intoxicated,
(ßedi of table fc)

In the event of a celebration, you can use the

first example i »Table 1 to 9.7" Vt »»! ■ · About which he wished a Ureas »re * I ₁ Q '' ** / | | ktAi« » _f « mrd · fiiitllt, that the

ftersJiisii "if §4 H nVjti"! tüd d »r Draikabfall over it»! Tilter aui 101 »·! ssb fttse «rsi» ie ittükka. Vtntt die Diateäesa- ~ earth i ·· eirst · «Contributed in table 1 imrih y» rili kohlt »dir Teserde alt OberflMehe · re« 1 109 ■ * / · bsw. 140 ■ * / · »rsetst, see Bk iff proportion of the ams-filled tar« ter SO % _t i * both * groove · up to 41 Jt. «· Β · the surface of the« erVse «tenerd · in

10 9811/1344

2 · 2

was kept within the specified limits of 1.5 m / g and 1.1 m / g in awei examples, but the pore diameter was reduced to below the lower limit to 1 or 1.1 m / g in the two examples, the Efficiency of tar removal to below the lower limit to 33 or 32 % . When reducing the surface of the first acetatellulose material * - as in Table 1 to below the lower critical limit to 0.1 κ / g, the pressure drop across the filter rose to 88.0 mn water column and the proportion of tar filtered out was reduced.

- Fftteatassyrtteke -

109811/134 A

Claims (14)

Patent claims ti ./Filter material for tobacco smoke with numerous porous in individual particles arranged in mutual contact, characterized in that each of the individual particles has an area size between 0.5 and 5.0 m / g, preferably between 1 and 3 μ / g, an average pore diameter between 2 and 10 / A.m and has a porosity of 30 to 90 Jf. 2. Filter material according to claim 1, characterized in that the porous individual particles have the shape of a granulate with a grain size that can be passed through a sieve with a mesh size of 0.841 mm (20 mesh), preferably 0.595 mm (80 mesh), and passed through a sieve with a mesh size of 0.149 mm (100 mesh), preferably 0.177 mm (80 mesh), retained will. 3. Filter material according to claim 1, further characterized in that that the individual particles are fibrous flakes with a length of about 0.5 to 25 mm and a thickness of about 0.025 to 0.25 mm, preferably about 0.03 mm, and a width of about 0.25 mm to 2 mm, preferably about 1.0 mm. 4. Filter material according to claim 2 or 3, gekennxelehnet through a bulk density of about 0.05 to 0.4 g / cm, preferably * 3 "'■■■ ν · η 0.09 to 0.3 g / cm. ■■ '.: ■■■■ ■. - 24 - 10 981 5. Filter material according to claims 1 to 4, characterized in that that the individual particles are made of a porous thermoplastic resin. 6. Filter material according to claims 1 to 5, characterized in that that the porous individual particles are interconnected at random locations. 7. Filter for a cigarette with a tubular outer Filter cover and one of a number of porous individual particles arranged in mutual contact Inner filling formed by filter material, characterized by a filter material according to at least one of the claims 1 to 6. 8. cigarette with a filter, characterized in that the filter with a material according to at least one of the claims 1 to β is filled. Θ. A method of producing a porous thermoplastic material by including starch bodies in a thermoplastic resin, the swelling of the starch and washing of the starch, characterized in that the starch has such a swelling capacity that the starch after swelling diameter of 2 to 10 U ■ have. 10. The method according to claim 9, characterized in that the thermoplastic resin is acetate cellulose. 1 0 9 8 1 1/1? ', U - 26 - 11. The method according to claim 10, characterized in that the Starch in a viscous solution of Acetatzelluloae in powder form in acetone is enclosed that the acetone is removed from the dough thus obtained and that subsequently the dried material is treated under pressure at elevated temperatures. 12. The method according to claim 11, characterized in that the Starch acetate cellulose particles before the starch swells be softened in an acetone-water solution. % 13. The method according to claim 11 or 12, characterized in that that the acetate cellulose pulp before and after the containment a saturated solution of sodium chloride in water is added to the starch « 14. The method according to claim 12 or 13, characterized in that the temperature of the starch-acetate cellulose-acetone-Waesergeaisohs zua swelling of the starch is increased. λ 16, method according to at least one «d · * claims 11» is 14, thereby characterized in that the Acetatxellulose-Aeeton-Gesiseh a Weicbjuoher "" is set and that the Qeaiaeh xur production tin ·· BIa tteat · rials by a heated «which is not heated * lfal * ensystea is led. 10 98 1 1/1? / ₊ 16, the method according to claim 15, characterized in that a Sheet material is formed which, when dry, has 80 to 85 j6 of the desired thickness of the porous material, that the sheet material for the production of fibrous, flaky strand material is comminuted so that the flaky strand material swells in the acetate cellulose contained starch is heated in water under pressure that the starch by adding τon alpha-amylase in compliance ο a temperature between 88 and 92 C is removed and that the flaky strand material is cooled and dried. ORIGINAL INSPECTED 1 0 9 8 1 1/1? / </ ♦