EP2066439A2 - Composite material of high cohesive strength, method of preparation and uses, especially in cigarette filters - Google Patents

Composite material of high cohesive strength, method of preparation and uses, especially in cigarette filters

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Publication number
EP2066439A2
EP2066439A2 EP07820122A EP07820122A EP2066439A2 EP 2066439 A2 EP2066439 A2 EP 2066439A2 EP 07820122 A EP07820122 A EP 07820122A EP 07820122 A EP07820122 A EP 07820122A EP 2066439 A2 EP2066439 A2 EP 2066439A2
Authority
EP
European Patent Office
Prior art keywords
composite material
characterized
particular
compound
material according
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.)
Pending
Application number
EP07820122A
Other languages
German (de)
French (fr)
Inventor
Robert Eberhardt
Eric Perin
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Rhodia Acetow AG
Original Assignee
Rhodia Operations Sas
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Priority to FR0608000A priority Critical patent/FR2905628B1/en
Application filed by Rhodia Operations Sas filed Critical Rhodia Operations Sas
Priority to PCT/EP2007/059515 priority patent/WO2008031816A2/en
Publication of EP2066439A2 publication Critical patent/EP2066439A2/en
Application status is Pending legal-status Critical

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Classifications

    • BPERFORMING OPERATIONS; TRANSPORTING
    • B01PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01JCHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J20/00Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof
    • B01J20/28Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof characterised by their form or physical properties
    • B01J20/28054Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof characterised by their form or physical properties characterised by their surface properties or porosity
    • B01J20/28078Pore diameter
    • AHUMAN NECESSITIES
    • A24TOBACCO; CIGARS; CIGARETTES; SMOKERS' REQUISITES
    • A24DCIGARS; CIGARETTES; TOBACCO SMOKE FILTERS; MOUTHPIECES FOR CIGARS OR CIGARETTES; MANUFACTURE OF TOBACCO SMOKE FILTERS OR MOUTHPIECES
    • A24D3/00Tobacco smoke filters, e.g. filter-tips, filtering inserts; Mouthpieces for cigars or cigarettes
    • A24D3/06Use of materials for tobacco smoke filters
    • A24D3/16Use of materials for tobacco smoke filters of inorganic materials
    • A24D3/163Carbon
    • AHUMAN NECESSITIES
    • A24TOBACCO; CIGARS; CIGARETTES; SMOKERS' REQUISITES
    • A24DCIGARS; CIGARETTES; TOBACCO SMOKE FILTERS; MOUTHPIECES FOR CIGARS OR CIGARETTES; MANUFACTURE OF TOBACCO SMOKE FILTERS OR MOUTHPIECES
    • A24D3/00Tobacco smoke filters, e.g. filter-tips, filtering inserts; Mouthpieces for cigars or cigarettes
    • A24D3/06Use of materials for tobacco smoke filters
    • A24D3/16Use of materials for tobacco smoke filters of inorganic materials
    • A24D3/166Silicic acid or silicates
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B01PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01JCHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J20/00Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof
    • B01J20/02Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof comprising inorganic material
    • B01J20/06Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof comprising inorganic material comprising oxides or hydroxides of metals not provided for in group B01J20/04
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B01PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01JCHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J20/00Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof
    • B01J20/02Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof comprising inorganic material
    • B01J20/06Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof comprising inorganic material comprising oxides or hydroxides of metals not provided for in group B01J20/04
    • B01J20/08Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof comprising inorganic material comprising oxides or hydroxides of metals not provided for in group B01J20/04 comprising aluminium oxide or hydroxide; comprising bauxite
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B01PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01JCHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J20/00Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof
    • B01J20/02Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof comprising inorganic material
    • B01J20/10Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof comprising inorganic material comprising silica or silicate
    • B01J20/103Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof comprising inorganic material comprising silica or silicate comprising silica
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B01PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01JCHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J20/00Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof
    • B01J20/02Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof comprising inorganic material
    • B01J20/10Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof comprising inorganic material comprising silica or silicate
    • B01J20/16Alumino-silicates
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B01PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01JCHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J20/00Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof
    • B01J20/02Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof comprising inorganic material
    • B01J20/20Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof comprising inorganic material comprising free carbon; comprising carbon obtained by carbonising processes
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B01PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01JCHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J20/00Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof
    • B01J20/28Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof characterised by their form or physical properties
    • B01J20/28002Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof characterised by their form or physical properties characterised by their physical properties
    • B01J20/28004Sorbent size or size distribution, e.g. particle size
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B01PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01JCHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J20/00Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof
    • B01J20/28Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof characterised by their form or physical properties
    • B01J20/28014Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof characterised by their form or physical properties characterised by their form
    • B01J20/28016Particle form
    • B01J20/28019Spherical, ellipsoidal or cylindrical
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B01PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01JCHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J20/00Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof
    • B01J20/28Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof characterised by their form or physical properties
    • B01J20/28014Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof characterised by their form or physical properties characterised by their form
    • B01J20/28026Particles within, immobilised, dispersed, entrapped in or on a matrix, e.g. a resin
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B01PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01JCHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J20/00Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof
    • B01J20/28Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof characterised by their form or physical properties
    • B01J20/28014Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof characterised by their form or physical properties characterised by their form
    • B01J20/2803Sorbents comprising a binder, e.g. for forming aggregated, agglomerated or granulated products
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B01PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01JCHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J20/00Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof
    • B01J20/28Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof characterised by their form or physical properties
    • B01J20/28054Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof characterised by their form or physical properties characterised by their surface properties or porosity
    • B01J20/28057Surface area, e.g. B.E.T specific surface area
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B01PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01JCHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J20/00Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof
    • B01J20/28Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof characterised by their form or physical properties
    • B01J20/28054Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof characterised by their form or physical properties characterised by their surface properties or porosity
    • B01J20/28069Pore volume, e.g. total pore volume, mesopore volume, micropore volume
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B01PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01JCHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J20/00Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof
    • B01J20/28Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof characterised by their form or physical properties
    • B01J20/28054Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof characterised by their form or physical properties characterised by their surface properties or porosity
    • B01J20/28078Pore diameter
    • B01J20/2808Pore diameter being less than 2 nm, i.e. micropores or nanopores
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B01PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01JCHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J20/00Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof
    • B01J20/28Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof characterised by their form or physical properties
    • B01J20/28054Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof characterised by their form or physical properties characterised by their surface properties or porosity
    • B01J20/28078Pore diameter
    • B01J20/28083Pore diameter being in the range 2-50 nm, i.e. mesopores

Abstract

The invention relates to a composite material of high cohesive strength, formed from at least one polymer and from at least one compound that is chosen from mineral oxides, aluminosilicates and active carbon, said composite material possessing: a mean particle size of at least 100 mm, a pore volume (Vd1) formed by pores with a diameter of between 3.6 and 1000 nm, equal to at least 0.2 cm3/g, a cohesive strength such that its content of particles with a size of less than 100 mm, obtained after being subjected to an air pressure of 2 bar, is less than 1.5%, preferably 0.0%, by volume. The invention also relates to a method of preparing said composite material. It also relates to the use of this composite material as liquid support, catalyst support, additive, or for liquid or gas filtration, in particular in cigarette filters.

Description

COMPOSITE MATERIALS WITH HIGH COHESION,

METHOD OF PREPARATION AND USES

PARTICULARLY IN CIGARETTE FILTERS

The present invention relates to high cohesive materials and to a high cohesive material preparation process.

It also relates to their uses, in particular as a liquid support, catalyst support, an additive or for liquid or gas filtration; it relates more particularly to their use in cigarette filters.

It is known to condition liquids on solid supports, in particular on a silica support. It is also known to use a compound such as activated carbon for its adsorption properties, especially for liquid or gas filtration, in particular in cigarette filters.

One of the aims of the invention is to provide a novel material having a high cohesion and preferably little or no dust, which can be used satisfactorily as a liquid support or for gas or liquid filtration, in particular in the cigarette filters, especially as an active filter, preferably by substitution of the activated carbon and / or in addition to traditionally used filter, such as cellulose acetate. The invention thus relates to a composite material, characterized in that it is formed by at least one polymer (P) and at least one compound (C) chosen from mineral oxides, aluminosilicates and activated carbon and it has:

- a median particle size of at least 100 microns, and preferably at most 2000 microns,

- a pore volume (Vd1), constituted by pores with a diameter between 3.6 and 1000 nm, of at least 0.2 cm 3 / g, - a cohesion such that its particle size ratio of less than 100 .mu.m obtained after an air pressure stress of 2 bars, according to the test described below, is less than 1, 5% by volume.

The polymer (P) is advantageously a porous polymer. The polymer (P) is in general chosen from the following polymers: cellulose and its derivatives (in particular cellulose acetate), starch and its derivatives, alginates and their derivatives, polyethylene, guars and their derivatives , polyvinyl alcohols and their derivatives.

The polymer (P) may be for example one of the polymer below: cellulose, cellulose acetate, cellulose sulfate, ethylcellulose, hydroxyethylcellulose, methylcellulose, hydroxymethylcellulose, carboxymethylcellulose, starch, carboxymethyl starch, hydroxypropyl starch, gum arabic, agar-agar, alginic acid, sodium alginate, potassium alginate, calcium alginate, tragacanth gum, guar gum, locust bean gum, polyvinyl acetates (possibly hydrolysed), copolymers of polyvinyl acetates and vinyl esters of aliphatic carboxylic acids, polyvinyl alcohols, polyethylene, copolymers of ethylene and vinyl esters of aliphatic saturated carboxylic acids, hydrated polycyclopentadiene. In particular, the polymer (P) may be cellulose or one of its derivatives

(Inter alia, cellose acetate or cellulose sulphate), polyethylene, gum arabic, polyvinyl alcohol.

More particularly, the polymer (P) may be a cellulose derivative (e.g., cellulose acetate, cellulose sulfate, ethylcellulose, hydroxyethylcellulose, methylcellulose, hydroxymethylcellulose, carboxymethylcellulose).

Very preferably, the polymer (P) is cellulose acetate. The compound (C) is most often an adsorbent and / or catalyst support. The compound (C) may be a mineral oxide, such as, in particular, a silica, an alumina, a zirconium oxide, a titanium oxide, an iron oxide, a cerium oxide

The compound (C) may also be an aluminosilicate. Finally, compound (C) can be activated carbon (in particular coconut activated carbon).

Thus, the compound (C) is generally chosen from silicas, aluminas, zirconium oxides, titanium oxides, iron oxides, cerium oxides, aluminosilicates and activated carbon.

The compound (C) is, for example a synthetic amorphous silica.

This can be a fumed silica, a colloidal silica, a silica gel, a precipitated silica or a mixture thereof. According to a preferred variant of the invention, the compound (C) is precipitated silica.

According to another preferred variant of the invention, the compound (C) is activated carbon.

The composite material may contain, according to one embodiment of the invention, a mixture of compounds (C), in particular a mixture of precipitated silica and activated carbon.

The composite material according to the invention may consist solely of at least one polymer (P) and at least one compound (C).

The median particle size (D50 in itiai) is measured by laser diffraction, for example according to standard NF X 1 1 -666, using a particle size analyzer of the type

Malvern Mastersizer 2000 (Malvern Instruments), in the absence of ultrasound and dispersant, the measurement liquid being degassed demineralized water (2 g of sample is dispersed in magnetic stirring 50 ml of water) and the duration the measurement being 5 seconds. The value used is the average of three consecutive measurements carried out on the same sample.

The cohesion is measured by the following cohesion test. Using a laser granulometer Malvern Mastersizer type 2000 (Malvern Instruments) coupled to the sampling module Scirocco dry. The analysis is carried out using the Fraunhofer optical model, with a measurement time of 5 seconds. A first analysis can be performed by introducing the product solely by the vibration of the hopper and aspiration, in order to have access to an initial size of the product.

A second analysis is carried out by injecting through the nozzle of the sampling module an air pressure of 2 bars. This pressure value has been define for granules made up solely of activated carbon, the activated carbon being a product already used in cigarette filters; it generates a sufficient stress to cause the beginning of the attrition of the activated carbon. This stress level thus corresponds to the appearance of fine particles (particle size less than 100 microns) in the case of activated carbon alone; it serves as a reference value for positioning the composite materials according to the invention.

The potential rate fine particles generated by this constraint assesses cohesion (hardness) of a product. The following measurements on the activated carbon alone are the reference values ​​vis-à-vis which the composite materials according to the invention can be evaluated (% by volume): 2 bar: size of particles smaller than 100 .mu.m = 2.0% particle size of rate less than 20 microns = 0.0% for information, to 0 bar (that is to say without air pressure): size of particles smaller than 100 .mu.m = 0 , 0% particle size of rate less than 20 microns = 0.0% It should be noted that the detection of fine particles (particle size less than 100 microns) without air pressure result the presence of a very fragile product . The cohesion of the composite materials according to the invention shows especially their ability to resist a level of stress without forming significantly and advantageously without forming at all, fine particles which can in particular be inhaled by the smoker when these materials are used in cigarette filters. The pore volumes and pore diameters are measured by mercury porosimetry (Micromeritics Autopore 9520 porosimeter, for example); for these measurements, the preparation of each sample may be as follows: each specimen is predried for 2 hours at 90 ° C under atmospheric pressure and then placed in a test container within 5 minutes following this drying and degassed under vacuum , for example using a vacuum pump; the sample plugs are 0.22 gram (± 0.01 gram); is employed penetrometers No. 10. The pore diameters are calculated by the Washburn relationship with an angle of contact theta equal to 140 ° and a surface tension gamma equal to 484 dynes / cm. In the present specification shall be taken into account that the pores having a diameter between 3.6 and 1000 nm.

The composite material according to the invention has a median particle size of at least 100 microns, especially at least 200 microns. Preferably, the latter is at most 2000 microns. It may be between 100 and 1000 .mu.m, in particular between 200 and 1000 microns, eg between 200 and 900 .mu.m. In general, it has a median particle size greater than 250 microns (especially varying from 250 (not included) to 2000 microns or even to 1000 microns), preferably of at least 300 .mu.m, in particular between 300 and 2000 microns, in particular between 300 and 1000 .mu.m.

Its median particle size is generally between 400 and 1000 .mu.m, in particular between 500 and 1000 .mu.m, in particular between 600 and 1000 microns, eg between 600 and 900 .mu.m.

The composite material according to the invention may, for example when intended for use in a cigarette filter, particle sizes between 100 and 2000 .mu.m, in particular between 200 and 1500 .mu.m, in particular between 200 and 800 microns or between 400 and 800 .mu.m.

The composite material according to the invention is, advantageously, porous. II has an intra-particle pore volume (Vd 1), constituted by pores with a diameter between 3.6 and 1000 nm (that is to say, cumulative pore volume of pores with a diameter between 3.6 and 1000 nm ), of at least 0.2 cm 3 / g, and usually at most 3.0 cm 3 / g (cm 3 per gram of composite material). Its pore volume (Vd1) is generally at least 0.3 cm 3 / g (e.g., between 0.3 and 3.0 cm 3 / g), preferably (particularly in the case where the compound (C ) is activated carbon) of at least 0.4 cm 3 / g, in particular between 0.4 and 3.0 cm 3 / g, for example between 0.4 and 2.0 cm 3 / g, or between 0.45 and 1, 5 cm 3 / g. Particularly in the case where the compound (C) is silica (preferably precipitated silica), the pore volume (MCV) of the composite material of the invention may be at least 0.5 cm 3 / g, in particular between 0.5 and 3.0 cm 3 / g, for example between 0.5 and 2.0 cm 3 / g, or even between 0.55 and 1, 5 cm 3 / g. Even more preferably, its pore volume (Vd1) is at least 0.7 cm 3 / g, in particular between 0.7 and 3.0 cm 3 / g, in particular between 0.7 and 2.0 cm 3 / g, for example between 0.75 and 1, 5 cm 3 / g.

The composite material according to the invention has a high cohesive strength. It has a cohesion such that its particle size ratio of less than 100 .mu.m obtained after an air pressure stress of 2 bars, according to the cohesion test described above, is less than 1, 5%, preferably less than 0.5% by volume.

Its size ratio of particles less than 20 microns obtained after an air pressure stress of 2 bars, according to the cohesion test described above, is generally equal to 0.0% by volume.

Its size ratio of particles less than 20 microns and a particle size ratio of less than 100 .mu.m obtained without air pressure stress, according to the cohesion test described above, are generally equal to 0, 0% by volume.

Advantageously, more particularly when intended for use in a cigarette filter, and for example, among others, when the compound (C) is silica (preferably precipitated silica) and / or coal active, its cohesion is such that its particle size ratio of less than 100 .mu.m obtained after an air pressure stress of 2 bars, according to the cohesion test described above, is equal to 0.0% in volume.

The composite material according to the invention preferably does not generate dust during its handling.

The composite material according to the present invention has, preferably, notably when it is used in a cigarette filter, a filtration capacity close to, or even greater than, that of the compound (C) used in its composition, in particular when the compound (C) is activated carbon and / or silica (preferably precipitated silica), while having a better cohesion. And this is particularly the case when the polymer (P) is cellulose acetate.

The composite material according to the invention may have, especially when the compound (C) is silica, in particular precipitated silica, an average pore diameter, for pores of diameter between 3.6 and 1000 nm, greater than 1 1nm (for example between 1 1 (not included) and 100 nm or between 1 1 (not included) and 50 nm), preferably at least 1 1, 5 nm, for example between January 1 , 5 to 100 nm; it can be between 1 1, 5 and 50 nm, in particular between 1 1, 5 and 40 nm, especially between 12 and 40 nm, for example between 12 and 25 nm or between 12 and 17 nm; it may also vary between 13 and 40 nm, especially between 13 and 25 nm, for example between 13.5 and 25 nm, or between 13.5 and 17 nm.

The composite material according to the invention, which is advantageously in solid form, usually has a BET surface area of at least 50 m 2 / g. In general, its BET specific surface area is at most 1300 m 2 / g and in particular at most 1200 m 2 / g, especially at most 1000 m 2 / g, for example at most 900 m 2 / g, or even at most 700 m 2 / g (m 2 per gram of composite material).

The BET surface area is determined according to the Brunauer - Emmett - Teller method described in "The Journal of the American Chemical Society", Vol. 60, page 309, February 1938 and corresponding to the NF ISO 9277 (December 1996).

The BET surface area of the composite material according to the present invention may be at least 100 m 2 / g, generally at least 160 m 2 / g, preferably at least 200 m 2 / g (for example greater than to 300 m 2 / g); it may be between 250 and 1300 m 2 / g, especially between 280 and 1200 m 2 / g, for example between 280 and 800 m 2 / g. It may also be between 320 and 1000 m 2 / g, especially between 320 and 900 m 2 / g, especially between 320 and 700 m 2 / g, even between 320 and 600 m 2 / g. For example in the case where the compound (C) is silica, in particular precipitated silica, the BET specific surface area of the composite material according to the invention may be between 250 and 800 m 2 / g, especially between 250 and 600 m 2 / g; for example in the case where the compound (C) is activated carbon, it may be between 400 and 1300 m 2 / g, especially between 400 and 1000 m 2 / g.

The surface area of ​​composite material according to the invention is essentially a function of the surface area of ​​the compound (C), its compound (C) content and the accessibility of the surface of the compound (C) within the composite material , that allows the porosity of the polymer (P). Preferably, the composite material of the invention retains a large portion (e.g. at least 60%) of the surface area of ​​the compound (C), in particular when the polymer (P) is cellulose acetate, especially in the case where the compound (C) is activated carbon and / or especially silica (preferably precipitated silica).

According to a particular embodiment, more particularly when it is intended to be used in a cigarette filter, and for example, among others, when the compound (C) is silica (preferably precipitated silica) and / or activated carbon, the composite material according to the invention has a median particle size of at least 300 microns (and for example of at most 2000 microns), in particular between 400 and 1000 microns, eg between 500 and 1000 microns, a BET surface area greater than 300 m 2 / g (and for example at most 1200 m 2 / g), in particular between 320 and 900 m 2 / g, especially between 320 and 700 m 2 / g , for example between 320 and 500 m 2 / g, even between 340 and 430 m 2 / g, and a cohesion such that its particle size ratio of less than 100 .mu.m obtained after an air pressure stress of 2 bars, according to the test described above, is equal to 0.0% by volume. In this embodiment, the polymer (P) is preferably cellulose acetate. In general, the composite material of the invention has a polymer (P) content between 10 and 95%, preferably between 15 and 45% by weight, and a compound (C) content between 5 and 90% , preferably between 55 and 85% by weight.

The composite material according to the present invention may especially be in the form of extrudates, for example in cylindrical form, or preferably in the form of granules, in particular substantially spheroidal. It may contain, in addition to the polymer (P) and the compound (C), at least one flavor and / or at least one plasticizer.

The invention also relates to a process for preparing a composite material process, in particular the composite material according to the invention described in the foregoing description, comprising the following successive steps:

1) adding at least one compound (C) chosen from mineral oxides, aluminosilicates and activated carbon in at least one polymer (P) solution, preferably with stirring,

2) shaping the resulting mixture, preferably by granulation or by extrusion,

3) introducing into a non-solvent of the polymer liquid (P) and at least partly miscible with the solvent used in the polymer solution (P), of the shaped product in order to insolubilize said polymer (P),

4) washing (s) of the product obtained to eliminate, at least partially, the solvent used in the polymer solution (P),

5) drying.

The polymer (P) used is, advantageously, a porous polymer.

The polymer (P) is in general chosen from the following polymers: cellulose and its derivatives (in particular cellulose acetate), starch and its derivatives, alginates and their derivatives, polyethylene, guars and their derivatives , polyvinyl alcohols and their derivatives.

The polymer (P) may be for example one of the polymer below: cellulose, cellulose acetate, cellulose sulfate, ethylcellulose, hydroxyethylcellulose, methylcellulose, hydroxymethylcellulose, carboxymethylcellulose, starch, carboxymethyl starch, hydroxypropyl starch, gum arabic, agar-agar, alginic acid, sodium alginate, potassium alginate, calcium alginate, tragacanth gum, guar gum, locust bean gum, polyvinyl acetates (possibly hydrolysed), copolymers of polyvinyl acetates and vinyl esters of aliphatic carboxylic acids, polyvinyl alcohols, polyethylene, copolymers of ethylene and vinyl esters of aliphatic saturated carboxylic acids, hydrated polycyclopentadiene. In particular, the polymer (P) may be cellulose or one of its derivatives (amongst others, cellulose acetate or cellulose sulphate), polyethylene, gum arabic, polyvinyl alcohol.

More particularly, the polymer (P) may be a cellulose derivative (e.g., cellulose acetate, cellulose sulfate, ethylcellulose, hydroxyethylcellulose, methylcellulose, hydroxymethylcellulose, carboxymethylcellulose).

Very preferably, the polymer (P) is cellulose acetate. The compound (C) used is most often an adsorbent and / or catalyst support.

The compound (C) used may be a mineral oxide, such as, in particular, a silica, an alumina, a zirconium oxide, a titanium oxide, an iron oxide, a cerium oxide.

The compound (C) may also be an aluminosilicate. Finally, compound (C) can be activated carbon (in particular coconut activated carbon).

Thus, the compound (C) is generally chosen from silicas, aluminas, zirconium oxides, titanium oxides, iron oxides, cerium oxides, aluminosilicates and activated carbon. The compound (C) is, for example a synthetic amorphous silica.

This can be a fumed silica, a colloidal silica, a silica gel, a precipitated silica or a mixture thereof.

According to a preferred variant of the invention, the compound (C) is precipitated silica. Thereof may be prepared by precipitation of a silicate reaction, such as an alkali metal silicate (sodium silicate for example), with an acidifying agent (sulfuric acid for example) to give a silica suspension precipitated, and then, usually, separating, particularly by filtration (to give a filter cake) the precipitated silica obtained, and finally drying (generally by atomization); the method of preparing the precipitated silica can be any: in particular, addition of acidifying agent on a silicate vessel, total or partial simultaneous addition of acidifying agent and silicate to a stock of water and silicate. According to another preferred variant of the invention, the compound (C) is activated carbon.

According to one embodiment of the invention, a mixture of compounds (C), in particular a mixture of precipitated silica and activated carbon.

The compound (C) employed in step 1) of the process according to the invention advantageously has a relatively high specific surface. It generally has, in particular in the case of a precipitated silica and / or activated carbon, a BET surface area of at least 100 m 2 / g, preferably at least 200 m 2 / g, in particular greater 450 m 2 / g.

The compound (C) usually has a median size of at least 0.5 .mu.m particles, in particular between 0.5 and 100 .mu.m.

When the compound (C) is precipitated silica, this size is preferably more particularly between 0.5 and 50 .mu.m, in particular between 0.5 and 20 .mu.m, for example between 2 and 15 .mu.m.

When the compound (C) is activated carbon (in particular coconut activated carbon), this size is preferably more particularly between 1 and 80 .mu.m, in particular between 2 and 70 .mu.m.

The compound (C) used in step 1) of the process according to the invention, in particular when it is silica, notably precipitated silica, preferably has a DOP oil uptake lower than 260 ml / 100g , especially less than 240 ml / 100g, for example less than 225 ml / 100g. Its DOP oil uptake may be less than 210 ml / 100 g or 205 ml / 100g. Its DOP oil uptake may be of at least 80 ml / 100g, especially greater than 145 ml / 100g, for example greater than 180 ml / 100g. The DOP oil uptake is determined according to standard

ISO 787/5 implementing dioctylphthalate (the measurement is performed on the compound (C) as is).

The compound (C) used, in particular when it is silica, notably precipitated silica, and / or activated carbon, generally posède a CTAB specific surface area (external surface area determined according to standard NF T 45007 (November 1987) ) greater than 280 m 2 / g, in particular greater than 300 m 2 / g, in particular greater than 330 m 2 / g, for example greater than 350 m 2 / g; it may be less than 450 m 2 / g. May in particular be employed in step 1) of the process according to the present invention a particular precipitated silica having:

- a DOP oil uptake lower than 260 ml / 100g, especially less than 240 ml / 100g, in particular less than 225 ml / 100 g - a porous volume (V d25), formed by the pores of diameter less than

25 nm, greater than 0.8 ml / g, especially greater than 0.9 ml / g, for example at least 0.95 ml / g (pore volume determined by the method of Barett, Joyner and Halenda, known method BJH, described especially by F. Rouquerol, L Luciani Llewwellyn P., R. and J. Denoyel Rouquerol in "the Engineering Techniques", September 2001)

- a CTAB specific surface area greater than 280 m 2 / g, in particular greater than 300 m 2 / g, in particular greater than 330 m 2 / g, for example greater than 350 m 2 / g,

- preferably, a BET specific surface greater than 450 m 2 / g, for example greater than 510 m 2 / g.

This particular precipitated silica may have a pore diameter (d p), for pores of diameter less than 25 nm, taken at the maximum of the pore size distribution by volume, less than 12.0 nm, in particular less than 8 , 0 nm (method of Barett, Joyner and Halenda). It can be prepared by a process comprising reacting a silicate with an acidifying agent whereby is obtained a suspension of precipitated silica, then separating and drying (including spray) of this suspension, the reaction of silicate with the acidifying agent being carried out according to the following successive steps: (i) forming an initial vessel bottoms comprising a part of the total quantity of silicate involved in the reaction, the silicate concentration (expressed as SiO 2) in said foot of initial stock being between 10 and 50 g / L, preferably between 12 and 48 g / l, in particular between 15 and 45 g / L, and the temperature of said initial stock being between 40 and 65 ° C, (i ') optionally, said foot vessel is added to the acidifying agent, for 5 to 30 minutes until obtaining a pH value of the reaction medium between 3.5 and 8.5. (Ii) adding said base stock, preferably simultaneously, of the acidifying agent and the remaining amount of silicate, for 20 to

150 minutes, the amount of silicate added (expressed as

SiO 2) / quantity of silicate present in the initial base stock (expressed as SiO 2) being greater than 5: a) either at constant flow rates resulting in the end of this simultaneous addition at a pH value of the reaction medium comprised between 3.5 and 8.5, b) an acidifying agent flow rate controlled to maintain the pH of the reaction medium at a constant value and between 3.5 and 8.5, (iii) adding to the reaction medium, in the case where the pH value of the reaction medium at the end of step (ii) is greater than 6.0, acidifying agent, for 3 to 25 minutes, so as to reach a value pH of the reaction medium between 3.5 and 6.0, (iv) the reaction medium is maintained, obtained at the end of the previous step, stirring for 5 to 60 minutes.

The surface of the compound particle (C) used, in particular when it is a precipitated silica, may first be functionalized, especially by grafting or adsorption of organic molecules, comprising for example at least one amino, phenyl, alkyl, cyano, nitrile, alkoxy, hydroxyl, amide, thio and / or halogen.

In step 1) of the process according to the invention, mixing the compound (C) with a solution of the polymer (P), preferably with stirring and, in particular, in a progressive manner, so as to obtain a mixture as homogeneous as possible. This step amounts to dispersing the compound (C) (in solid form) in a medium consisting of polymer (P) in solution in one of its solvents. It is optionally possible to use here a granulator type mixer, for example of Rotolab Zanchetta.

Can be used as a solvent, e.g., acetic acid (in particular when the polymer (P) is cellulose acetate), water (particularly in the case where the polymer (P) is the sulfate cellulose, polyvinyl alcohol, gum arabic), a naphthenic oil (in particular in the case where the polymer (P) is polyethylene). When the polymer (P) is cellulose acetate, it is generally dissolved in an acetic acid + water mixture, for example in the following mass proportions: cellulose acetate: 10 to 25% acetic acid: 65 to 80% water: 5 to 15%

An addition of solvent (e.g. acetic acid in the case where the polymer (P) is cellulose acetate) may be carried out on the mixture formed at the end of step 1) or in the solution of polymer (P), particularly to reduce its viscosity.

The proportions of polymer (P) and compound (C) used in step 1) depend on the proportions desired in the final composite material, and are, in general, such that it has a polymer content (P ) of between 10 and 95%, preferably between 15 and 45% by weight, and a compound (C) content between 5 and 90%, preferably between 55 and 85% by weight.

Step 2) shaping the mixture obtained after step 1) may be conducted by compaction (for example using a compactor Alexanderwerk). Preferably, step 2) is rather carried out by granulation or extrusion.

The granulation may take place continuously or discontinuously. The product obtained is in the form of granules.

It can be performed in a mechanical granulator rotor. May be employed a rotor granulator equipped with plowshares, in particular a Lόdige granulator at moderate shear rates.

The granulation is preferably carried out in a granulator high shear rate.

preferably employs a rotor granulator equipped with blades or pins, in particular a Rotolab Zanchetta granulator, which typically operates in discontinuous.

The granulation is usually carried out under stirring. It can be performed at room temperature (temperature of the place of installation).

In general, 25 to 75% of the volume of the container (tank) of the granulator, in particular in the case of a Rotolab Zanchetta granulator, are initially filled with the mixture obtained at the end of step 1).

The rotor speed of the granulator, in particular in the case of a Rotolab Zanchetta granulator, may be between 200 and 1000 revolutions / min, for example between 400 and 600 revolutions / min.

Extrusion may be a high pressure extrusion (for example by means of an apparatus such press piston) or a low pressure extrusion (for example by means of an apparatus such Fuji Paudal). The extrudates obtained are generally in cylindrical form.

The method according to the invention may comprise, at the end of step 2), a possible calibration step and / or grinding in order to remove any materials not having the desired size. The method may optionally further comprise a step of spheronization, so as to increase the spheroidal character of the product.

In step 3) of the process according to the invention is insolubilized (precipitates) the polymer (P) by introducing into a liquid which is not a solvent for said polymer (P) and which is at least partly (preferably totally) miscible with the solvent used in the polymer solution (P) implemented in step 1), the product from step 2) shaping. The insolubilization of the polymer (P) transforms it into a porous solid matrix having dispersed therein the compound (C). Can be used as non-solvent of the polymer liquid (P), for example, water (in particular when the polymer (P) is cellulose acetate and the solvent employed acetic acid), an aqueous solution (diluted) acetic acid (in particular when the polymer (P) is cellulose acetate and the solvent employed acetic acid), ethanol (in particular in the case where the polymer (P) is the sulfate cellulose and the solvent employed water), a carboxylic acid (especially in the case where the polymer (P) is polyvinyl alcohol and the solvent employed water), an alcohol (particularly in the case where the polymer (P) is gum arabic and the solvent used in (hot) water), hexane (in particular in the case where the polymer (P) is polyethylene and the solvent employed a naphthenic oil).

The non-solvent of the polymer liquid (P) is in general preheated. In particular when the polymer (P) is cellulose acetate and said liquid is water, the product from step 2) can be introduced into said liquid is at a temperature between 30 and 90 ° C, in particular between 45 and 75 ° C or between 50 and 70 ° C; here we can introduce e.g. about 70 to 130 grams of product from step 2) per liter of water.

Step 3) is generally carried out with stirring. Step 4) the process according to the invention consists of one or more washes of the product obtained after step 3) (after separating the liquid used in step 3)), to eliminate, at least partially, preferably totally the residual solvent. This washing can be performed with water, particularly in the case where the solvent used for the polymer (P) is acetic acid.

Then, after a possible squeezing step (preferably light), the method according to the invention comprises a step 5) of drying, especially in order to remove the washing liquid used in step 4).

In particular when the washing liquid is water, in particular when the polymer (P) is cellulose acetate, the drying step may be carried out at a temperature between 50 and 120 ° C, for example in a device (especially an oven or fluid bed) broken, generally for 2 to 60 hours, in particular between 5 and 30 hours.

The method according to the invention may comprise, after the drying step, an optional step of grinding and / or sifting (separation) in order to remove any materials not having the desired size, including the intended applications . The resulting composite material can have, for example when intended for use in a cigarette filter, particle sizes between 100 and 2000 .mu.m, in particular between 200 and 1500 .mu.m, in particular between 200 and 800 .mu.m, or between 400 and 800 .mu.m.

The procécé according to the invention makes it possible, advantageously, to prepare a composite material having a filtration capacity at least as high, in general higher, than that of compound (C) used, in particular when the compound (C) is activated carbon and / or especially silica (preferably precipitated silica). And it can be even more the case when the polymer (P) used is cellulose acetate.

Similarly, preferably, the method according to the invention allows to obtain a composite material that retains a large portion (e.g. at least 60%) of the surface area of ​​the compound (C) used, in particular when the polymer ( P) is cellulose acetate, especially in the case where the compound (C) is activated carbon and / or especially silica (preferably precipitated silica). The composite material according to the invention or (capable of being) obtained by the method of the invention can be used in particular as a liquid support.

As a liquid, organic liquids such as organic acids there may be mentioned the surfactants, organic additives for rubber / polymers, pesticides.

Can be employed as liquid preservatives (phosphoric acid, propionic acid especially), aromas, colorants, liquid food supplements, including animal (in particular, vitamins (vitamin E for example), choline chloride) . The composite material according to the invention or (capable of being) obtained by the method of the invention can be used as catalyst support.

It can be also used as an additive, especially for bulk materials or thin layers. It can be used as paper additive, paint, or for preparing battery separators. The composite material according to the invention or (capable of being) obtained by the method of the invention can be used for liquid filtration (for example for filtering beer) or for gas filtration, especially in chromatography.

So he finds particularly interesting application in cigarette filters. It may for example be introduced into a cavity filter or dispersed within the network of fibers making up one of the filter segments. It advantageously has a good absorption capacity for volatile and semi-volatile components of cigarette smoke. Its filtration capacity is, preferably, close to or even greater than, that of the compound (C) alone. Its characteristics allow a reasonable increase in the pressure loss in the filter and an entrainment of fine particles in the lower smoke than in the case of traditional additives, such as activated carbon and silica, when the cigarette is smoked.

The present invention finally relates to a cigarette filter containing at least one composite material according to the invention or (capable of being) obtained by the method of the invention; said composite material may comprise at least two compounds (C) different, for example precipitated silica and activated carbon.

Thus, a composite material containing several compounds (C) of different types may advantageously be introduced into the same filter, using conventional technologies, as if it were a single additive. The invention can therefore also be capable of providing an advantage in terms of cost and filters diversity.

The following examples illustrate the invention but without limiting its scope.

EXAMPLES 1 -5

In Examples 1 to 3, is used as starting material, as compound (C), a precipitated silica, in powder form, having the following characteristics:

- BET specific surface area 550 m 2 / g - oil uptake (DOP) 200 ml / 100g

- median particle size 23 microns

- moisture (ISO 787/2 standard, 105 ° C, 2h) 7%

In the example 4, is used as starting material, as compound (C), coconut activated carbon in powder form, marketed by the company Pica (containing 0.5% water, having a median particle size below 80 .mu.m and a BET specific surface area of 821 m 2 / g.

In Examples 1 to 4, is used as feedstock, as polymer (P), cellulose acetate in solution in acetic acid. Specifically, the used cellulose acetate solution contains 18% cellulose acetate, 1 1% water and 71% acetic acid.

EXAMPLE 1

First, a mixture is prepared by adding 139 grams of precipitated silica into 300 grams of cellulose acetate solution.

To this is added gradually precipitated silica to the cellulose acetate solution, this incorporation being carried out with stirring (stirrer motor equipped with a frame paddle), so as to obtain a homogeneous mixture.

Then the resulting mixture is introduced into the bowl of a Rotolab Zanchetta granulator and granulation was performed under the following conditions:

- temperature: room temperature - speed of the rotor of the granulator: 500 turns / min

- granulation time: 25 minutes

The granules obtained after granulation are poured into preheated water at 60 ° C, wherein they remain for 15 minutes, the water being subjected to stirring. After removal of water, the granules are washed 5 times with cold water (duration of each wash: 15 minutes) to remove residual acetic acid.

After filtering, the granules are dried in a ventilated oven for 12 hours at a temperature of 95 ° C. The characteristics of the composite material thus obtained (reference MC1) are presented in Table 1.

EXAMPLE 2

First, a mixture is prepared by adding 139 grams of precipitated silica into 300 grams of cellulose acetate solution.

To this is added gradually precipitated silica to the cellulose acetate solution, this incorporation being carried out with stirring (stirrer motor equipped with a frame paddle), so as to obtain a homogeneous mixture; the product obtained is placed in the bowl of a Rotolab Zanchetta granulator, in which it is subjected to stirring (rotor speed: 500 revolutions / min) at room temperature for 5 minutes. Then the resulting mixture is introduced into the cylindrical screen of a Fuji Paudal extruder, screen pierced with orifices with a diameter of 500 .mu.m, and extrusion is carried out by rotating the rotor that pushes the mixture through the screen, generating cylindrical extrudates and 500 microns in diameter. The application of an air stream used to limit bonding between several cylindrical extrudates.

The extrudates obtained were then poured in water preheated at 60 ° C, wherein they remain for 15 minutes, the water being subjected to stirring.

After removal of the water, the extrudates were washed 5 times with cold water (duration of each wash: 15 minutes) to remove residual acetic acid.

After a light wiping, the extrudates were dried in a ventilated oven for 12 hours at a temperature of 95 ° C.

The characteristics of the composite material thus obtained (reference MC2) are presented in Table 1.

Example 3

First, a mixture is prepared by adding 13.9 grams of precipitated silica in 30.0 grams of cellulose acetate solution.

To this is added gradually precipitated silica to the cellulose acetate solution, this incorporation being carried out with stirring (stirrer motor equipped with a frame paddle), so as to obtain a homogeneous mixture. Then the resulting mixture is introduced into the piston body by a press piston extruder and extrusion is carried out by passing the mixture through a pad breakthrough of orifices with a diameter of 800 .mu.m, thus generating Cylindrical extrudates 800 microns in diameter. The extrudates obtained were then poured in water preheated at 60 ° C, wherein they remain for 15 minutes, the water being subjected to stirring.

After removal of the water, the extrudates were washed 5 times with cold water (duration of each wash: 15 minutes) to remove residual acetic acid.

After a light wiping, the extrudates were dried in a ventilated oven for 12 hours at a temperature of 95 ° C.

The characteristics of the composite material thus obtained (referred to MC3) are presented in Table 1.

EXAMPLE 4

First, a mixture is prepared by adding 109.7 grams of activated charcoal in 200 grams of cellulose acetate solution.

To this was gradually added the activated carbon to the cellulose acetate solution, this incorporation being carried out with stirring (stirrer motor equipped with a frame paddle), so as to obtain a homogeneous mixture. Then the resulting mixture is introduced into the piston body by a press piston extruder and extrusion is carried out by passing the mixture through a pad breakthrough of orifices with a diameter of 1000 .mu.m, thereby generating Cylindrical extrudates 1000 microns in diameter.

The extrudates obtained were then poured in water preheated at 60 ° C, wherein they remain for 15 minutes, the water being subjected to stirring.

After removal of the water, the extrudates were washed 5 times with cold water (duration of each wash: 15 minutes) to remove residual acetic acid. After a light wiping, the extrudates were dried in a ventilated oven for 12 hours at a temperature of 95 ° C.

The characteristics of the composite material thus obtained (reference MC4) are presented in Table 1. Table 1

measured by the cohesion test mentioned in the description (% by volume)

It can be seen in particular that the composite materials according to the invention (MC1, MC2, MC3, MC4) for each of which the rate of particle diameter less than 100 microns obtained after an air pressure stress of 2 bars (measured by the cohesion test mentioned in the description) equal to 0.0%, have a higher cohesion than the silica alone (for which the rate is 10%) and the activated carbon alone (for which the rate is 2.0%).

EXAMPLE 5

In order to evaluate their adsorption properties of semi-volatile and volatile compounds in cigarette smoke stream, the composite materials obtained in Examples 1 and 3 are implemented, after sieving between 400 and 800 .mu.m, in cigarette samples made from the tobacco part of standard samples CORESTA MONITOR # 4 having associated therewith a cavity filter mounted manually. This filter consists of a segment 8 mm long cellulose acetate, a cavity completely filled (without dead volume) of the additive to be tested and another segment of 8 mm long cellulose acetate the additive to be tested is made either by one of composite materials of example 1 and 3, either silica alone or from activated carbon alone (corresponding to those used as starting material in the above examples) by reference ; in these last two cases, the amount of silica or of carbon used in the filter is equal to the quantity of silica present in the filter containing the composite material of Example 1 or 3. The length of the cavity containing the additive is about 9 mm.

After manually mounting the filter, each cigarette sample was conditioned for 90 hours at 60% relative humidity at a temperature of 22 ° C, then smoked on a smoking machine rotary positions 20 Borgwaldt (RM20H).

The filter output smoke passes through a filter "Cambridge" allowing only the vapor phase, this then being recovered by cold traps filled with methanol.

Volatile and semi-volatile compounds are recovered then analyzed by gas chromatography coupled to mass spectrométhe (GC / MS).

The rates of reduction of the volatile and semi-volatile species indicated in Table 2 below are determined relative to those obtained with cigarettes of the same type, but for which a cavity with a length of 9 mm is left empty between two cellulose acetate segments.

Table 2

It can be seen that the composite materials MC1 and MC3 have very satisfactory adsorption properties. They allow to obtain rate reduction of volatile species and semi-volatile superior to those obtained with silica alone and overall at least equivalent or even superior to those obtained with activated carbon alone, while presenting a better cohesion.

Claims

1 - Composite material, characterized in that it is formed of at least one polymer (P) and at least one compound (C) chosen from mineral oxides, aluminosilicates and activated carbon and in that he owns :
- a median particle size of at least 100 microns,
- a pore volume (MCV), constituted by pores with a diameter between 3.6 and 1000 nm, of at least 0.2 cm 3 / g, - a cohesion such that its particle size ratio of less than
100 .mu.m obtained after an air pressure stress of 2 bars is less than 1, 5% by volume.
2- Composite material according to Claim 1, characterized in that said polymer (P) is chosen from the following polymers: (derivatives of) cellulose, (derivatives of) starch, derivatives (alginate), polyethylene, (derivatives ) guars and (derivatives of) polyvinyl alcohols.
3. Composite material according to one of claims 1 and 2, characterized in that said polymer (P) is cellulose acetate.
4- Composite material according to one of claims 1 to 3, characterized in that said compound (C) is selected from silicas, aluminas, zirconium oxides, titanium oxides, iron oxides, oxides of cerium, aluminosilicates and activated carbon.
5- Composite material according to one of claims 1 to 4, characterized in that said compound (C) is precipitated silica.
6- Composite material according to one of claims 1 to 4, characterized in that said compound (C) is activated carbon. 7- Composite material according to one of claims 1 to 4, characterized in that said compound (C) is a mixture of precipitated silica and activated carbon.
8- Composite material according to one of claims 1 to 7, characterized in that its mean particle size is at least 200 .mu.m, preferably of at least 300 .mu.m, in particular between 300 and 1000 .mu.m, for exemle between 400 and 1000 .mu.m.
9- Composite material according to one of claims 1 to 8, characterized in that its pore volume (Vd 1), constituted by pores with a diameter between 3.6 and 1000 nm, is at least 0.3 cm 3 / g, preferably at least 0.4 cm 3 / g, in particular between 0.4 and 3.0 cm 3 / g, in particular between 0.4 and 2.0 cm 3 / g, e.g. between 0.45 and 1, 5 cm 3 / g.
10- Composite material according to one of claims 1 to 8, characterized in that its pore volume (Vd 1), constituted by pores with a diameter between 3.6 and 1000 nm, is at least 0.5 cm 3 / g, in particular between 0.5 and 3.0 cm 3 / g, in particular between 0.5 and 2.0 cm 3 / g, for example between 0.55 and 1, 5 cm 3 / g.
11 - Composite material according to one of claims 1 to 10, characterized in that it has a cohesion such that its particle size ratio of less than 100 .mu.m obtained after a strain of 2 bar air pressure is less than 1, 0%, preferably less than 0.5%, in particular equal to 0.0% by volume.
12- Composite material according to one of claims 1-1 1, characterized in that it has a cohesion such that its particle size ratio of less than 20 microns obtained after an air pressure stress of 2 bars is equal to 0.0% by volume. 13- Composite material according to one of claims 1 to 12, characterized in that its average pore diameter, for pores of diameter between 3.6 and 1000 nm, is greater than 1 1nm, preferably at least 1 1, 5 nm, in particular between 1 1 5 and 100 nm, especially between 12 and 50 nm, for example between 12 and 25 nm.
14- Composite material according to one of claims 1 to 13, characterized in that it has a BET specific surface of at least
50 m 2 / g, in particular at least 100 m 2 / g, more particularly at least 160 m 2 / g, especially at least 200 m 2 / g, for example between 250 and
1300 m 2 / g.
15- Composite material according to one of claims 1 to 14, characterized in that it has a median particle size of at least 300 .mu.m, in particular between 400 and 1000 microns, a BET surface area greater than 300 m 2 / g, in particular between 320 and 1000 m 2 / g, for example between 320 and 700 m 2 / g, and a cohesion such that its particle size ratio of less than 100 .mu.m obtained after a strain pressure air bars 2 is equal to 0.0% by volume.
16- Composite material according to one of claims 1 to 15, characterized in that it has a polymer (P) content between 10 and 95%, preferably between 15 and 45% by weight and a content of compound (C) of between 5 and 90%, preferably between 55 and 85% by weight.
17- Composite material according to one of claims 1 to 16, characterized in that it is in cylindrical form or as granules.
18- Composite material according to one of claims 1 to 17, characterized in that it further contains at least one flavor and / or at least one plasticizer. 19- A process for preparing a composite material, in particular a composite material according to one of claims 1 to 18, comprising the following successive steps:
1) adding at least one compound (C) chosen from mineral oxides, aluminosilicates and activated carbon, in a polymer (P) solution, preferably with stirring,
2) shaping the resulting mixture, preferably by granulation or by extrusion,
3) introducing into a non-solvent of the polymer liquid (P) and at least partly miscible with the solvent used in the polymer solution (P), of the shaped product in order to insolubilize said polymer (P),
4) washing (s) of the product obtained to eliminate, at least partially, the solvent used in the polymer solution (P),
5) drying.
20- Method according to claim 19, characterized in that said polymer (P) is chosen from the following polymers: (derivatives of) cellulose, (derivatives of) starch, derivatives (alginate), polyethylene, (derivatives) guars and (derivatives of) polyvinyl alcohols.
21 - Method according to one of claims 19 and 20, characterized in that said polymer (P) is cellulose acetate.
22- Method according to claim 21, characterized in that the cellulose acetate solution used in step 1) contains acetic acid as solvent.
23- Method according to one of claims 21 and 22, characterized in that the liquid non-solvent for cellulose acetate used in step 3) is water or an aqueous solution of acetic acid.
24- Method according to one of claims 19 to 23, characterized in that said compound (C) is selected from silicas, aluminas, zirconium oxides, titanium oxides, iron oxides, cerium oxides , aluminosilicates and activated carbon.
25- Method according to one of claims 19 to 24, characterized in that said compound (C) is precipitated silica.
26- Method according to one of claims 19 to 24, characterized in that said compound (C) is activated carbon.
27- Method according to one of claims 19 to 24, characterized in that said compound (C) is a mixture of precipitated silica and activated carbon.
28- Method according to one of claims 19 to 27, characterized in that said compound (C) has a BET surface area of at least 100 m 2 / g, preferably at least 200 m 2 / g, in especially greater than 450 m 2 / g.
29- Method according to one of claims 19 to 28, characterized in that step 2) shaping is performed by granulation in a granulator equipped with blades or pins, in particular a Zanchetta granulator.
30- Method according to one of claims 19 to 28, characterized in that step 2) shaping is performed by low-pressure or high-pressure extrusion.
31 - Use of a composite material according to one of claims 1 to
18 or obtainable by the method according to one of claims
19-30 as the liquid medium.
32- Use of a composite material according to one of claims 1 to 18 or obtainable by the method according to one of claims 19 to 30 as a solid support, as an additive or for liquid or gas filtration.
33. For use in cigarette filters of a composite material according to one of claims 1 to 18 or obtainable by the method according to one of claims 19 to 30.
34- Use according to Claim 33, characterized in that said composite material comprises at least two compounds (C) different, for example precipitated silica and activated carbon.
35- Cigarette filter characterized in that it contains at least one composite material according to one of claims 1 to 18 or obtainable by the method according to one of claims 19 to 30.
36. Filter cigarette according to claim 35, characterized in that said composite material comprises at least two compounds (C) different, for example precipitated silica and activated carbon.
EP07820122A 2006-09-13 2007-09-11 Composite material of high cohesive strength, method of preparation and uses, especially in cigarette filters Pending EP2066439A2 (en)

Priority Applications (2)

Application Number Priority Date Filing Date Title
FR0608000A FR2905628B1 (en) 2006-09-13 2006-09-13 Composite Material of cohesion high, process for the preparation and uses, including filters to cigarettes.
PCT/EP2007/059515 WO2008031816A2 (en) 2006-09-13 2007-09-11 Composite material of high cohesive strength, method of preparation and uses, especially in cigarette filters

Publications (1)

Publication Number Publication Date
EP2066439A2 true EP2066439A2 (en) 2009-06-10

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EP07820122A Pending EP2066439A2 (en) 2006-09-13 2007-09-11 Composite material of high cohesive strength, method of preparation and uses, especially in cigarette filters

Country Status (12)

Country Link
US (1) US9808785B2 (en)
EP (1) EP2066439A2 (en)
JP (1) JP5204109B2 (en)
KR (1) KR101160501B1 (en)
CN (1) CN101583417B (en)
BR (1) BRPI0716769B1 (en)
CA (1) CA2663549C (en)
FR (1) FR2905628B1 (en)
MX (1) MX2009002752A (en)
RU (1) RU2436624C2 (en)
UA (1) UA102217C2 (en)
WO (1) WO2008031816A2 (en)

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Also Published As

Publication number Publication date
FR2905628A1 (en) 2008-03-14
WO2008031816A2 (en) 2008-03-20
UA102217C2 (en) 2013-06-25
CA2663549A1 (en) 2008-03-20
RU2436624C2 (en) 2011-12-20
MX2009002752A (en) 2009-03-26
WO2008031816A3 (en) 2008-06-26
KR20090069274A (en) 2009-06-30
KR101160501B1 (en) 2012-06-28
CN101583417A (en) 2009-11-18
CA2663549C (en) 2014-11-18
BRPI0716769A2 (en) 2013-09-17
FR2905628B1 (en) 2011-01-21
BRPI0716769B1 (en) 2018-02-06
JP2010503391A (en) 2010-02-04
US9808785B2 (en) 2017-11-07
JP5204109B2 (en) 2013-06-05
US20100043813A1 (en) 2010-02-25
CN101583417B (en) 2013-10-30
RU2009113600A (en) 2010-10-20

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