JPH08187074A - Filter material and production thereof - Google Patents

Abstract

PURPOSE: To suppress the production of acidic odor components such as acetic acid odor in a filter material containing cellulose fiber and activated charcoal. CONSTITUTION: This method for producing a filter material for cigarettes consists of an adding process where an adsorbent such as active charcoal and a powdery or granular thermoplastic resin having hot melt adhesiveness to an opened tow of cellulose ester fiber, a forming process where the tow containing the resin in wound to form a rod, a heat treating process where the rod is heat treated and the resin is melted in or after the forming process and a cooling process where the rod is cooled. The amounts to be added are 1-200 pts.wt. adsorbent and 0.5-50 pts.wt. thermoplastic resin having 50-200 deg.C melting point, 10-500μm average particle diameter based on 100 pts.wt. tow.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a filter material useful for controlling an acidic odor such as acetic acid in a cigarette filter and the like, and a method for producing the same. The present invention also provides a tobacco filter including the filter material,
It also relates to a method for suppressing the production of acidic odor components.

[0002]

2. Description of the Related Art Tobacco filters composed of fiber bundles of cellulose ester are widely used in order to remove tars from cigarette smoke and not impair taste. In such a cigarette filter, in order to maintain the shape of the filter plug and obtain the hardness necessary for cutting the filter tip from the filter plug, an ester plasticizer (for example, triacetin, triethylene glycol diacetate, as a binder, Triethylene glycol dipropionate, dibutyl phthalate, dimethoxyethyl phthalate, citric acid triethyl ester, etc.) have been used.

In the filter plug formed by using the plasticizer, fibers are partially fused by the plasticizer. That is, the plasticizer has a function as a binder that randomly binds to each other at the contact site of the cellulose ester fiber.

Further, a tobacco filter material in which activated carbon is added to the cellulose ester fiber bundle in addition to the ester plasticizer in order to remove harmful components and enhance taste is also known. However, when the ester-based plasticizer and activated carbon coexist, the acidic odor increases, which may give a smoker an aversion. For example, adding either one of the components of triacetin and activated carbon to the cellulose acetate fiber bundle produces almost no odorous component, while storing the filter containing both the components of triacetin and activated carbon to the cellulose acetate fiber bundle. Then, an acetic acid odor is generated. Especially when stored under high temperature such as in summer, the odor of acetic acid becomes strong. This is presumably because triacetin is adsorbed on the activated carbon, and the triacetin is decomposed by the activation action of the activated carbon to generate an acetic acid odor.

Furthermore, when a tobacco filter using an ester plasticizer as a binder is used and then discarded, it takes a long time for the shape to collapse in the environment, which not only impairs the appearance but also causes environmental pollution. Become.

Japanese Unexamined Patent Publication No. 56-24151 discloses a filter containing cellulose acetate fibers and heat-fusible fibers for heat-bonding these fibers at the intersections. Fibrillated polyolefin fibers or the like are used as the heat-fusible fibers. JP-B-44-277
Japanese Unexamined Patent Publication No. 19 discloses a filter containing viscose rayon fibers and a thermoplastic resin fine powder (polyvinyl acetate, polyethylene powder, etc.) for heat-sealing these fibers at intersections. Also, JP-A-56-118
Japanese Patent No. 939 discloses that cellulosic fibers to which substances capable of mutually adhering cellulosic fibers are adhered are wrapped in a wrapper sheet (wrapping paper) to be molded into a rod-shaped body, which is then subjected to microwave treatment to obtain shape stability. A method of making a good filter is disclosed.

However, these prior documents do not disclose that an acidic odor component is produced in the coexisting system of activated carbon and ester plasticizer. Furthermore, since the heat-fusible fiber and the resin fine powder are not water-soluble, the filter does not substantially show disintegration in water.

[0008]

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a filter material capable of suppressing the generation of an acidic odor component even if an adsorbent such as activated carbon and a binder coexist in a cellulose ester fiber bundle, and a production thereof. To provide a method.

Another object of the present invention is to provide a filter material capable of remarkably suppressing the production of acetic acid odor even when stored at a high temperature for a long period of time, and a method for producing the same.

Still another object of the present invention is to provide a filter material which has appropriate breathability and hardness and does not impair the taste of cigarettes, and a method for producing the same.

Another object of the present invention is to provide a cigarette filter having the above-mentioned excellent characteristics.

Still another object of the present invention is to provide a method capable of remarkably suppressing the production of acidic odor components even when a filter containing cellulose ester fibers coexisting with an adsorbent such as activated carbon is stored at high temperature for a long period of time. To provide.

Yet another object of the present invention is to provide, in addition to the above properties, a filter material which can be easily disintegrated by wetting and a cigarette filter provided with the same.

[0014]

Means for Solving the Problems As a result of intensive studies to achieve the above object, the present inventors have found that a powdery or granular thermoplastic resin having hot melt adhesiveness is added as a binder in place of an ester plasticizer. Even if an adsorbent such as activated carbon coexists, the production of acidic odor components such as acetic acid odor is significantly suppressed, and the obtained filter has an appropriate hardness without impairing the flavor and taste. Found and completed the present invention.

That is, the filter material of the present invention contains a cellulose ester fiber, an adsorbent, and a thermoplastic resin having a hot melt adhesive property. The adsorbent includes activated carbon, and the thermoplastic resin has a melting point of 50 to 2
Includes resin at about 00 ° C. The thermoplastic resin is often a powdery or granular material, and the average particle size thereof is, for example, 10 to 10.
It may be about 500 μm.

The filter material has a hot-melt adhesive property for adhering the cellulose ester fiber bundle, the powdery granular activated carbon contained in the fiber bundle, and the cellulose ester fiber to hold the powdered granular activated carbon in the fiber bundle. It is composed of a granular thermoplastic resin and often has a rod shape.

In such a filter material, the proportion of each component is, for example, 1 to 200 parts by weight of an adsorbent and 0.5 to 50 parts by weight of a granular thermoplastic resin to 100 parts by weight of cellulose ester fiber. It is a degree.

The filter material is useful as a constituent material of a cigarette filter. Therefore, the tobacco filter of the present invention includes the rod-shaped filter material.

Further, in the method of the present invention, the production of the acidic odor component can be suppressed by coexisting the adsorbent and the granular thermoplastic resin having hot melt adhesiveness in the cellulose ester fiber bundle.

The rod-shaped filter material and the rod for a tobacco filter are made by adding an adsorbent and a powdery thermoplastic resin having hot-melt adhesiveness to the tow of cellulose ester fiber, the adsorbent and the heat. Wrap (wrap around) a tow containing a plastic resin with wrapping paper
A molding step of molding into a rod, a heat treatment step of heating the rod to melt at least the surface of the thermoplastic resin after the molding step or the molding step, and a cooling step of cooling the rod after the heat treatment step It can be manufactured.

Among the resins, there is a resin which does not show a clear melting point and softens at a specific temperature. In this specification,
"Melting point" is used to include the softening point of such resins. Further, a thermoplastic resin having hot melt adhesiveness may be simply referred to as "thermoplastic resin" or "resin", and a thermoplastic water-soluble resin may be simply referred to as "water-soluble resin".

The present invention will be described in detail below.

Examples of the cellulose ester include organic acid esters such as cellulose acetate, cellulose butyrate and cellulose propionate; inorganic acid esters such as cellulose nitrate, cellulose sulfate and cellulose phosphate; cellulose acetate propionate,
Examples thereof include mixed acid esters such as cellulose acetate butyrate, cellulose acetate phthalate and cellulose nitrate acetate; and cellulose ester derivatives such as polycaprolactone-grafted cellulose acetate. These cellulose esters may be used alone or in combination of two or more.

The average degree of polymerization of the cellulose ester is, for example, 10 to 1000, preferably 50 to 900, more preferably about 200 to 800, and the average degree of substitution of the cellulose ester is, for example, about 1 to 3. Cellulose esters having an average degree of substitution of 1 to 2.15, preferably about 1.1 to 2.0 are useful for increasing biodegradability.

Preferred cellulose esters include organic acid esters (for example, esters with organic acids having about 2 to 4 carbon atoms), particularly cellulose acetate. The acetylation degree of cellulose acetate is often about 43 to 62%, but the cellulose ester having an acetylation degree of about 30 to 50% is also excellent in biodegradability. Therefore, the acetylation degree of cellulose acetate can be appropriately selected within the range of about 30 to 62%.

In addition to the above-mentioned cellulose ester fibers, for example, rayon fibers, polypropylene fibers, polyethylene fibers, polyester fibers, nylon fiber bundles can be used as long as they do not impair smoking properties and filterability. Other fibers such as fibers may be included. A preferred fiber bundle can consist solely of cellulose ester fibers.

The above-mentioned cellulose ester fibers are added to various additives such as kaolin, talc, diatomaceous earth,
Inorganic fine powder such as quartz, calcium carbonate, barium sulfate, titanium oxide and alumina; heat stabilizer such as salt of alkaline earth metal such as calcium and magnesium; coloring agent;
Oil agent; it may contain a yield improver and the like. Further, the degradability of the fiber can be enhanced by incorporating an environmental decomposition promoter (biodegradation promoter) such as citric acid, tartaric acid, malic acid, etc., a photodegradation promoter such as anatase type titanium oxide, etc.

Further, the cellulose ester fiber often contains a whiteness improving agent, for example, titanium oxide, preferably anatase type titanium oxide. The average particle diameter of titanium oxide is, for example, 0.1 to 10 μm, preferably 0.2 to 5
It is often about μm. The content of titanium oxide is 0.05 to 2.0% by weight, preferably 0.1 to 1% by weight, and more preferably 0.2 to 0.8% by weight, based on the whole cellulose ester, It is often 0.4 to 0.6% by weight.

The fineness of the cellulose ester fiber is 1 to 1
6 denier, preferably 1 to 10 denier, more preferably 2 to 8 denier. The cellulose ester fibers may be non-crimped fibers, but are preferably crimped fibers. The crimping degree of the crimped fiber is, for example, 5 to 75, preferably 10 to 50, and more preferably 15 to 50 per inch. The crimp degree of the fiber is often about 20 to 50 per inch. In many cases, uniformly crimped fibers are used. By using crimped fibers, it is possible to obtain a filter material (rod) having appropriate ventilation resistance and suppressed channeling, and it is possible to effectively join the fibers even if the amount of the thermoplastic resin attached is small. .

The cross-sectional shape of the cellulose ester fiber is not particularly limited, and is, for example, a circle, an ellipse, or an irregular shape (for example,
The shape may be any of Y-shape, X-shape, I-shape, R-shape, etc. and hollow shape.

The tow (fiber bundle) composed of cellulose ester fibers is, for example, 3,000 to 1,000,000.
It can be formed by bundling 0, preferably about 5,000 to 100,000 single fibers of cellulose ester fibers. The fiber bundle is often formed by bundling about 3,000 to 100,000 continuous fibers.

The filter material of the present invention contains, in addition to the cellulose ester fiber, an adsorbent for improving the tobacco taste by selective removal of gas phase components. Examples of the adsorbent include natural or synthetic zeolite, activated alumina, silica gel, bentonite, acid clay, and activated carbon. Preferred adsorbents include activated carbon.

The activated carbon may be various activated carbons, for example,
Fruit shell charcoal such as coconut shell and walnut shell, plant-based activated carbon such as charcoal, phenol resin, rayon, polyvinylidene chloride, acrylic resin, synthetic resin made of polymers such as cellulose, polymer-based activated carbon, brown charcoal, rake Mineral activated carbon using mineral raw materials such as blue coal, anthracite, coke, coal or petroleum pitch is included. These activated carbons may be used alone or in combination of two or more. Of these activated carbon, plant-based activated carbon such as coconut shell activated carbon is often used.

In the adsorbent such as the above-mentioned activated carbon, a non-volatile agent such as an acid component such as an organic acid or an inorganic acid, an organic base or an inorganic base, etc. is added in order to enhance the selective removal property against a harmful component as necessary. A base component may be supported.

The adsorbent such as activated carbon may be fibrous, but is often used in the form of powder. The adsorbent may be a granulated product granulated with a binder, such as granulated activated carbon. The average particle size of the particulate adsorbent can be selected from a wide range that does not impair the flavor and the integrity of the filter material, and is, for example, 0.1 to 1000 μm, preferably 5
˜500 μm, more preferably about 10 to 300 μm. The average particle size of the powdery adsorbent is, for example, 1
It is often 6 to 200 mesh, preferably 20 to 150 mesh, and more preferably 28 to 60 mesh.

The specific surface area of the adsorbent can be selected within a range that does not impair the efficiency of removing harmful components such as phenols, and is, for example, 200 to 4000 m ² / g, preferably 300 to 3.
000 m ² / g, more preferably 500-2500 m
² / g, and often 1000 to 2000 m ² / g.

The adsorbent may be uniformly distributed throughout the cellulose ester fiber bundle, or may be nonuniform or partially present. When the adsorbent is partially distributed in the fiber bundle, for example, it may be present in the central portion or the outer peripheral portion along the axial direction of the cellulose ester fiber bundle, and may be in a ring shape or a spiral shape. It may be distributed or present in various shapes.

The amount of the adsorbent added to the cellulose ester fiber can be selected from the viewpoints of the efficiency of removing harmful components and the flavor and taste. For example, 1 to 200 parts by weight, preferably 10 to 150 parts by weight, relative to 100 parts by weight of the cellulose ester fiber. Parts by weight, more preferably 25 to 120 parts by weight (eg,
30 to 100 parts by weight), and often 50 to 100 parts by weight.

A feature of the present invention is that in a system in which an adsorbent such as activated carbon coexists, a thermoplastic resin having hot melt adhesiveness is added to the cellulose ester fiber in place of the ester plasticizer to generate an acidic odor component. There is a point to suppress. That is, the hot-melt adhesive thermoplastic resin has a larger molecular weight than the ester plasticizer and is not decomposed even by the activation action of the adsorbent such as activated carbon. Therefore, in the method of the present invention, even if the adsorbent (particularly activated carbon) and a thermoplastic resin having hot melt adhesiveness are added to the cellulose ester fiber bundle to allow the adsorbent and the thermoplastic resin to coexist, The generation of acidic odor can be significantly suppressed over a period of time. In particular, since it is not necessary to use triacetin, which is commonly used as a binder for cellulose ester fibers, the generation of acetic acid odor can be prevented.

The thermoplastic resin having hot melt adhesiveness is preferably nontoxic and tasteless and odorless since it does not impair the flavor and safety. Further, the thermoplastic resin preferably has a colorless and transparent hue or a white hue from the viewpoint of the appearance of the filter material.

The thermoplastic resin may be any resin that contains a water-insoluble or sparingly water-soluble resin and a water-soluble resin, and exhibits adhesive force by melting and solidifying. The water-insoluble or poorly water-soluble resin and the water-soluble resin may be used in combination as necessary. The filter material using a water-soluble resin as the thermoplastic resin is excellent in disintegrating properties when wet, and even if accidentally thrown into the environment after smoking, it quickly disintegrates into fibrous form due to water such as rainwater, It can reduce pollution and is effective for maintaining the aesthetics of the environment.

Examples of the water-insoluble or sparingly water-soluble resin include olefin homopolymers or copolymers such as polyethylene, polypropylene, ethylene-propylene copolymer, ethylene-vinyl acetate copolymer, polyvinyl acetate, polymethacrylic acid. Acrylic resins such as methyl, methyl methacrylate-acrylic acid ester copolymers, copolymers of (meth) acrylic monomers and styrene monomers, polyvinyl chloride, vinyl acetate-vinyl chloride copolymers, polystyrene, styrene Styrene-based polymers such as copolymers of monomers and (meth) acrylic monomers, optionally modified polyester, nylon 11, nylon 1
2, polyamides such as nylon 610 and nylon 612, rosin derivatives (eg, rosin ester), hydrocarbon resins (eg, terpene resin, dicyclopentadiene resin, petroleum resin, etc.), hydrogenated hydrocarbon resins and the like. These thermoplastic resins may be used alone or in combination of two or more.

The water-soluble resin includes various water-soluble polymers such as polyvinyl alcohol, polyvinylpyrrolidone,
Polyvinyl ether, a vinyl monomer, a carboxyl group, a vinyl-based water-soluble resin such as a copolymer of a copolymerizable monomer having a sulfonic acid group or a salt thereof, an acrylic water-soluble resin, polyalkylene oxide, Water-soluble polyester, water-soluble polyamide and the like are included.

Examples of polyvinyl alcohol include polyvinyl alcohol such as completely saponified polyvinyl alcohol and partially saponified polyvinyl alcohol, and derivatives of polyvinyl alcohol (eg, partially acetalized polyvinyl alcohol and acryl-modified polyvinyl alcohol). An ethylene unit may be introduced into the polyvinyl alcohol by copolymerization.

The polyvinyl ether includes, for example, polyvinyl methyl ether, polyvinyl ethyl ether, polyvinyl propyl ether, polyvinyl isopropyl ether, polyvinyl butyl ether, polyvinyl isobutyl ether and the like.

The copolymer of a vinyl monomer and a copolymerizable monomer having a carboxyl group, a sulfonic acid group or a salt thereof includes a vinyl monomer such as vinyl acetate, vinylpyrrolidone, vinyl alkyl ether and styrene. Monomers and α, β-ethylenically unsaturated carboxylic acids such as (meth) acrylic acid, maleic anhydride, maleic acid and crotonic acid or acid anhydrides thereof, α, β-ethylenically unsaturated such as ethylenesulfonic acid A copolymer with sulfonic acid or a derivative thereof is included, and the copolymer may be a copolymer with another monomer such as (meth) acrylic acid ester, if necessary. When the α, β-ethylenically unsaturated carboxylic acid or its acid anhydride is a polyvalent carboxylic acid or its acid anhydride, it is a half-ester with an alcohol or a diester with an alcohol within a range not impairing the water solubility. May be used as. The vinyl monomer and the copolymerizable monomer may be used alone or in combination of two or more to form a copolymer. Examples of such a copolymer include vinyl acetate-maleic acid copolymer, vinyl acetate-crotonic acid copolymer, vinyl acetate-acrylic acid copolymer,
Vinyl alcohol-maleic acid copolymer, vinyl alcohol-ethylene sulfonic acid copolymer, vinyl alcohol- (meth) acrylic acid copolymer, vinyl methyl ether-maleic acid copolymer, vinyl ethyl ether-maleic acid copolymer , Vinyl isobutyl ether-maleic acid copolymer, styrene- (meth) acrylic acid copolymer, styrene-maleic acid copolymer, styrene-crotonic acid copolymer and the like.

The acrylic water-soluble resin includes an acrylic resin having water solubility imparted by (meth) acrylic acid or a salt thereof, such as polyacrylic acid and a salt thereof (for example, sodium polyacrylate or ammonium polyacrylate). ), Polymethacrylic acid and its salts, copolymers of (meth) acrylic acid alkyl esters such as methyl methacrylate and butyl acrylate with (meth) acrylic acid, polyacrylic acid ester partial saponification products, and polyacrylic acid ester copolymers. Examples thereof include partially saponified polymers and polyacrylic amides.

Polyalkylene oxide includes polyethylene oxide (polyethylene glycol), polypropylene oxide (polypropylene glycol), ethylene oxide-propylene oxide and the like. The water-soluble polypropylene oxide often has a molecular weight of 1,000 or less. The hydroxyl group of polyalkylene oxide may be blocked with a terminal blocking agent such as an organic carboxylic acid. The polyalkylene oxide having hot melt adhesiveness has a molecular weight of 3,000 to 100,000, preferably 5,000.
It is often a polyethylene oxide of about 0 to 50,000.

Examples of the water-soluble polyester include (1) polyester using at least polyethylene glycol as a glycol component, (2) polyvalent carboxylic acid having 3 or more carboxyl groups in one molecule, or sulfoisophthalic acid. A polyester obtained by using a dicarboxylic acid having a sulfonic acid group as part or all of the carboxylic acid component and neutralizing the remaining carboxyl group or sulfonic acid group with an alkali metal such as sodium or potassium, ammonia or amines, (3) A combination of (1) and (2), that is, a polyester obtained by using at least a polyethylene glycol and a polycarboxylic acid having 3 or more carboxyl groups in one molecule or a dicarboxylic acid having a sulfonic acid group, included. As the polyethylene glycol, in order to impart high water solubility, for example, polyethylene glycol having a molecular weight of about 200 to 5,000 may be used.

The water-soluble polyamide is (4) a polyamide obtained by reacting a diamine having a polyethylene glycol unit as a diamine component with a dicarboxylic acid such as adipic acid or sebacic acid (JP-A-60-21928).
No. 1), (5) A polyamide obtained by reacting a diamine having a tertiary amino group (for example, aminoethylpiperazine, bisaminopropylpiperazine, etc.) with a dicarboxylic acid (JP-A-60-219281). (6) Polyamide in which sulfoisophthalic acid or a salt thereof is used as the dicarboxylic acid component and a group of a sulfonate salt is introduced (Japanese Patent Publication No. 57-8838). When preparing the polyamide, lactams such as ε-caprolactam may be used together. The polyethylene glycol unit has a molecular weight of 2 because it imparts high water solubility.
It may be about 00 to 5000.

In order to exhibit rapid disintegration with water,
The solubility of the hot-melt adhesive water-soluble resin in water at 20 ° C. is at least 5% by weight or more, preferably 10% by weight or more (for example, 30% by weight to infinity), and more preferably 50% by weight or more ( For example, about 50 to infinity). In the water-soluble resin having a carboxyl group or a sulfonic acid group introduced, the acid value is, for example, 30 to 300 KOH.
It is often about mg / g.

These water-soluble resins may be used alone or in combination of two or more. The polyvinyl alcohol hot melt adhesive has, for example, a polymerization degree of 1
000 or less (for example, 100 to 700), saponification degree 80
It may be composed of polyvinyl alcohol of not more than mol% (for example, 20 to 60 mol%), high-molecular-weight polyethylene glycol having an average degree of polymerization of 150 or more, and low-molecular-weight polyethylene glycol having an average degree of polymerization of 10 or less (for example, Japanese Unexamined Patent Publication (Kokai)) No. 5-65465).

When a water-soluble resin is used as an aqueous solution or an aqueous dispersion, the strength and hardness of the rod-shaped filter material is significantly reduced, and not only the winding operation of the tow with the wrapping paper but also the cutting property into chips is impaired. easy. on the other hand,
Since the hot-melt adhesive resin (water-soluble hot-melt adhesive) that exhibits adhesive strength by melting and solidifying is a solventless adhesive, the above-mentioned problems are solved. Moreover, when a water-soluble resin is used, a filter material having high disintegration can be obtained. Preferred water-soluble resins include, for example, vinyl-based resins such as polyvinyl alcohol, polyvinylpyrrolidone and polyvinyl ether, polyalkylene oxides, polyamides, polyesters and acrylic resins. Particularly, polyvinyl alcohol, polyalkylene oxide, polyamide, polyester, acrylic resin and the like are preferable.

The thermoplastic resin is solid at room temperature, and its melting point is, for example, 50 to 200 ° C., preferably 70 to 200 ° C.
170 degreeC, More preferably, it is about 80-150 degreeC, and is about 50-150 degreeC in many cases. If the melting point of the resin is less than 50 ° C, smoking may soften or melt the resin, and if it exceeds 200 ° C, the melting of the resin may damage the cellulose ester fiber. In addition, the decomposition temperature of the resin is often 200 ° C. or higher in order to effectively develop the adhesiveness by heating and melting. The softening point of the hot melt adhesive thermoplastic resin is, for example, 50
It is often about 200 to 200 ° C, preferably about 75 to 150 ° C.

The melt viscosity of the hot melt adhesive resin is 1
100 to 100,000 cps at 50 ° C., preferably 150 to 75,000 cps, more preferably 2
It is about 00 to 50,000 cps.

The hot-melt adhesive resin may be used in a fibrous form, but it is practically used as a powdery granular material in many cases in order to improve the adhesion efficiency to the cellulose ester fiber and the ability to retain activated carbon. The particle size of the thermoplastic resin powder or granular material can be selected within a range that effectively exhibits adhesiveness to the cellulose ester fiber and does not impair the winding operability, for example, an average particle size of 10 to 500 μm, preferably 30-300 μm, more preferably 50-2
It is about 00 μm. If the average particle size is less than 10 μm,
Since the amount of resin scattered by the winding operation is large and the recovery is difficult, the yield may be reduced and the winding operability may be impaired. On the other hand, if the average particle size exceeds 500 μm, the resin cannot be effectively used for bonding the cellulose ester fibers.

The amount of the resin used can be selected according to the type of the resin, the form of use and the characteristics of the cellulose ester fiber,
For example, 0.5 to 50 parts by weight (for example, 1 to 30 parts by weight), preferably 1 to 25 parts by weight, and more preferably 5 to 100 parts by weight of the tow of the cellulose ester fiber.
It is about 25 parts by weight and about 2 to 20 parts by weight (for example, 7
It is often about 20 to 20 parts by weight, especially 5 to 20 parts by weight). If the amount of the powdered or granular resin used is less than 0.5 parts by weight, the effect as a binder for the cellulose ester fiber is small, and the hardness required for the filter material is not developed. If it exceeds 50 parts by weight, the taste and the winding work are performed. Is easily damaged and wrinkles due to the thermoplastic resin are likely to occur on the wrapping paper.

Various additives such as antioxidants, stabilizers such as ultraviolet absorbers, fillers, plasticizers, preservatives and antifungal agents may be added to the thermoplastic resin.

In the method of the present invention, an adding step of adding an adsorbent and a thermoplastic resin in the form of powder or granules having hot melt adhesiveness to the tow of the cellulose ester fiber, and a tow containing the adsorbent and the thermoplastic resin is wrapped with a paper wrapper. A forming step of winding and forming into a rod, this forming step or after the forming step,
The heat treatment may be performed by heating the rod to melt at least the surface of the thermoplastic resin, and after the heat treatment, cooling the rod.

In such a method, the adsorbent and the granular thermoplastic resin can be added in the adding step by using, for example, an activated carbon powder adding device used for manufacturing a cigarette charcoal filter.

The tow of cellulose ester fiber is
It is preferable to open the fiber before adding the adsorbent and the granular resin to enhance the adhesiveness and holding ability of the adsorbent and the granular resin. The opening width of the tow can be selected in a wide range, for example,
Width 100-500mm, preferably 150-450mm
It is about 150 to 400 mm in many cases. When the tow is opened, the adsorbent such as activated carbon and the granular thermoplastic resin can be uniformly added to the whole, and the uniformity of filter characteristics including hardness can be improved.
In the opening step, various methods capable of opening the tow of the cellulose ester fiber, for example, the tow is hung on a plurality of opening rollers, and the width of the tow is gradually expanded as the tow progresses. It is possible to adopt a method of opening, a method of opening the fiber by repeating tension (extension) and relaxation (contraction) of the tow.

FIG. 1 is a schematic side view showing the addition device.
In this example, activated carbon is used as the adsorbent. Cellulose ester fiber tow 1 is conveyed while being opened by a conveying mechanism including a conveying roller (not shown),
Activated carbon as an adsorbent and a granular thermoplastic resin are sprayed from the supply roller 2 of the addition device to the opened continuous band-shaped tow 1. That is, the addition device includes a casing 3 as a hopper for containing a mixture of activated carbon and a granular thermoplastic resin, a supply roller 2 rotatably arranged in a lower opening of the casing, and a supply roller of the casing 3. 2, an opening degree adjusting plate 4 attached to the wall surface on the downstream side of 2, and a set bolt 5 and a washer 5a for adjusting the opening degree of the slit s between the adjusting plate and the supply roller 2.

When such an adding device is used, according to the opening of the slit s as the supply roller 2 rotates,
The activated carbon as the adsorbent and the thermoplastic resin can be uniformly supplied while being sprinkled on the opened tow 1. Further, the supply amounts of the activated carbon and the thermoplastic resin can be adjusted according to the opening degree of the slit s and the rotation speed of the supply roller 2. Therefore, the filter material obtained through such a molding step has high uniformity, has appropriate breathability and hardness, despite the use of a powdery or granular adsorbent and a thermoplastic resin, and has a flavor and aroma of tobacco. It does not spoil.

In the addition device, an adsorbent (activated carbon) is used.
Although a mixture of a thermoplastic resin and a thermoplastic resin is housed in the casing, the amount of scattering may increase or the uniform mixing and toughness may increase depending on the particle size and specific gravity of the adsorbent (activated carbon) and the granular thermoplastic resin. May be difficult to evenly distribute. In such a case, if the granular material with the thermoplastic resin adhering to the adsorbent (activated carbon) is sprayed and supplied to the tow,
It is possible to uniformly distribute while suppressing the amount of scattering, and it is possible to uniformly supply the activated carbon and the thermoplastic resin to the tow. In addition, by using the powder and granular material of the adsorbent and the thermoplastic resin, it is possible to adhere the cellulose ester fiber by the adhered thermoplastic resin, it is also possible to enhance the retention of the adsorbent (activated carbon) to the cellulose ester fiber, It is also possible to prevent the adsorbent (activated carbon) from falling off. In order to effectively utilize the thermoplastic resin for bonding to the cellulose ester fiber without impairing the adsorptive ability of the adsorbent, it is preferable that the thermoplastic resin is scattered in powder form on the surface of the adsorbent.

The method of adhering the thermoplastic resin to the adsorbent (activated carbon) is not particularly limited as long as the adsorbing ability of the adsorbent is not impaired. For example, a mixture of the adsorbent and a granular thermoplastic resin is mixed. While heating to the softening temperature or melting point of the thermoplastic resin, a method of heating the adsorbent and the granular thermoplastic resin while floating, a method of spraying the molten thermoplastic resin to the floating adsorbent can be exemplified. .

In the powdery or granular material, the ratio of the adsorbent to the thermoplastic resin can be appropriately selected. For example, the adsorbent 10
1 to 300 parts by weight, preferably 5 to 200 parts by weight, more preferably 10 to 50 parts by weight of 0 part by weight of the thermoplastic resin.
It is about 10 parts by weight, and often about 10 to 70 parts by weight.

Further, the activated carbon and the granular thermoplastic resin are 1
It is not necessary to supply the tow from one adding device at the same time. For example, even if a plurality of adding devices (usually two adding devices) are provided in the tow conveying direction and activated carbon and / or granular thermoplastic resin are sequentially supplied. Good. When using a plurality of adding devices, the order of adding the activated carbon and the thermoplastic resin is not particularly limited.

The activated carbon and the thermoplastic resin can be added to the tow using various devices, not limited to the above-mentioned addition device. For example, the thermoplastic resin may be added to the tow by melting and spraying.

Further, in the forming step, a conventional cigarette filter manufacturing apparatus for winding (wrapping) the tow with a wrapping paper to form a rod can be used. For example, a molding member composed of a funnel-shaped tube member is provided in the tow conveying path, opened into a band shape, and the tow to which the activated carbon and the thermoplastic resin have been added or sprinkled is passed through the molding member. As a result, the tow can be formed into a rod shape. Further, a plurality of forming members (usually two forming members) are provided in the tow conveying path, and the toe is formed into a rod shape by the first forming member as described above.
The rod can be rolled up by feeding the molded rod-shaped tow into the second molding member together with the wrapping paper which is unrolled from the wrapping paper roller and the adhesive is applied to the proper position such as one side by the gluing device. .

A water-insoluble resin may be used as the adhesive for adhering the wrapping paper, but in order to enhance the disintegration property or dispersibility of the filter with respect to water, a water-soluble resin, particularly a hot-melt adhesive property is used. It is preferable to use a resin. As the hot-melt adhesive resin, the same water-soluble resin as described above can be used.

In the above method, the tow is practically wound, for example, in the range of 200 to 1000 m / min, preferably 300 to 800 m / min (eg, 300 to 600 m / min).
Min) about as fast. The tow hoisting speed is 250
It is often about 700 m / min.

Further, in the heat treatment step and the cooling step, conventional heating means (eg, heater, hot air, microwave heater, etc.) and cooling means (eg, cooler, etc.) can be used. The heat treatment step can be performed after the forming step of forming the tow into a rod or after the forming step. Also,
In the heat treatment step, at least the surface of the thermoplastic resin contained in the rod may be melted, but the granular thermoplastic resin is often melted. In such a heat treatment step, since the thermoplastic resin has hot melt adhesiveness, the thermosetting resin efficiently bonds the cellulose ester fiber and / or the adsorbent by the heating operation. Furthermore, when a granular thermoplastic resin is used, heating efficiency and joining efficiency can be increased, and a highly integrated filter material having appropriate air permeability and hardness can be obtained.

After the heat treatment step, the rod-shaped filter material can be obtained by cooling the rod in the cooling step. When used as a material for a cigarette filter, a rod-shaped filter material is usually cut into a predetermined length to obtain a cigarette filter plug or a filter chip.

The filter material (rod) thus obtained is composed of a cellulose ester fiber bundle, a particulate adsorbent (activated carbon) contained in the fiber bundle, and a granular thermoplastic resin having hot melt adhesiveness. The thermoplastic resin adheres the cellulose ester fibers, and the fiber bundle holds a particulate adsorbent (activated carbon). In many cases, the adsorbent and the cellulose ester fiber are randomly bonded via the thermoplastic resin.

The filter material (rod-shaped filter material) is suitable as a constituent material of a cigarette filter. That is, the cigarette filter of the present invention comprises the rod-shaped filter material. More specifically, the filter material may form the entire tobacco filter, or may form a part of the tobacco filter by being interposed between a plurality of filter members (for example, two filter members). . The filter member may be configured as a crepe-shaped tobacco filter member made of wood pulp as a raw material or a tobacco filter member made of a regenerated cellulose fiber bundle, or a cellulose ester fiber such as a cellulose acetate fiber bundle. It is practically advantageous to construct the bundle. In the latter case, as the binder of the cellulose ester fiber, both the conventional ester plasticizer and the thermoplastic resin can be used. Further, when the thermoplastic resin is used as the binder, the use of the water-soluble resin can enhance the disintegration property of the tobacco filter due to the water, which is advantageous in reducing environmental pollution.

[0076]

INDUSTRIAL APPLICABILITY In the filter material of the present invention and the tobacco filter provided with the same, since the binder of the cellulose ester fiber is a thermoplastic resin, the acidic odor component is present even if the adsorbent such as activated carbon and the binder coexist. Can be suppressed. Further, only by using the thermoplastic resin having the hot melt adhesive property instead of the commonly used triacetin, it is possible to remarkably suppress the production of acetic acid odor even when stored at high temperature for a long period of time. Furthermore, when the thermoplastic resin is a powdery or granular material, the adsorbent and the thermoplastic resin can be supplied relatively evenly to the tow, so the filter material has a high degree of uniformity and an appropriate breathability and hardness. And does not impair the taste of cigarettes.

In the method of the present invention, since the thermoplastic resin has a hot melt adhesive property and is in the form of powder, it is possible to enhance the uniform supply property to the tow, the heating efficiency and the cooling efficiency in the heating step, and the cellulose. The tow of ester fibers can be wound up smoothly at high speed, and the filter material having the above-mentioned excellent properties can be efficiently produced.

In the method of the present invention, only by using the thermoplastic resin, an acidic odor component is produced even when a filter containing cellulose ester fibers coexisting with an adsorbent such as activated carbon is stored at high temperature for a long time. It can be significantly suppressed.

Further, when a water-soluble resin is used as the thermoplastic resin, even if it is accidentally thrown into the environment after smoking, it has an excellent disintegrating property when wet, and quickly disintegrates into fibrous form by water such as rainwater, It can reduce environmental pollution and is effective for maintaining the beauty of the environment.

[0080]

The present invention will be described in more detail based on the following examples, but the invention is not intended to be limited by these examples.

Example 1 Tow of cellulose acetate fibers composed of 3 denier filaments having a Y-shaped cross section (total denier 36
000) to a width of about 20 cm, and a hoisting machine (KDF2 / AC1 / AF) for manufacturing an activated carbon-added filter for cigarette smoke.
1; 80 parts by weight of activated carbon (specific surface area 1200 m ² / g, 28 to 60 mesh) (40 mg per 10 mm tow) based on 100 parts by weight of the opened tow using an activated carbon powder addition device manufactured by HAUNI Germany And powdery granular ethylene-vinyl acetate resin having hot melt adhesiveness (manufactured by Daido Kasei Co., Ltd., trade name DAIKALAC S1101,
15 parts by weight (60 mesh pass) were evenly dispersed. Next, the tow is supplied to a paper winding device, the tow is wound up with a winding paper at a winding speed of 400 m / min, the obtained filter rod is cut into a length of 120 mm, heated in an oven at 120 ° C. for 10 minutes, and cooled. By doing so, a filter plug was obtained.

Example 2 480 parts by weight of activated carbon of Example 1 and 100 parts by weight of the granular thermoplastic resin of Example 1 were mixed at 120 ° C. for 10 hours.
By heating for minutes and cooling, a granular material having a thermoplastic resin attached to the surface of activated carbon was prepared.

90 parts by weight of the above-mentioned powdery or granular material was replaced with 100 parts by weight of tow (74.5 parts by weight of activated carbon and 15.5 parts by weight of thermoplastic resin) in place of the activated carbon and the powdery or granular thermoplastic resin of Example 1. A filter plug was obtained in the same manner as in Example 1 except that the addition was made.

Comparative Example A filter plug was obtained in the same manner as in Example 1 except that 6 parts by weight of triacetin was applied to 100 parts by weight of tow of cellulose acetate fiber and then 80 parts by weight of activated carbon of Example 1 was added. .

Reference Example A tow of cellulose acetate fibers was wound up in the same manner as in Example 1 without using activated carbon and a binder,
A filter plug was obtained by cutting.

The filter plugs obtained in the examples, comparative examples and reference examples are as follows.
When the amount of acetic acid produced was measured and the odor was evaluated, the results shown in the table were obtained. In order to accelerate the production of acetic acid, the production amount of acetic acid was measured and the odor was evaluated for the filter plug stored in a closed container at 35 ° C. and 90% relative humidity for 1 month.

Amount of acetic acid produced: Five filter plugs from which the paper roll has been removed are placed in 60 ml of ethanol, and ultrasonic waves are irradiated for 30 minutes by an ultrasonic cleaner to extract acetic acid in the plugs and recover the extract. . 60 ml of ethanol is added to the remaining 5 filter plugs, and the above extraction operation is repeated to combine the extract with the recovered extract. 10 ml of the extract was added to a membrane filter (Milipore Millex-
GU, 0.22 μm) to remove finely powdered activated carbon, and 2 μl of the filtrate was subjected to gas chromatography (GC HP589).
0, column J & W DB-WAX (megabore column, 2
0m)) to quantify the amount of acetic acid produced.

Evaluation of odor: The degree of odor was evaluated according to the following criteria.

Level 0: No acetic acid odor Level 1: Slight acetic acid-like odor Level 2: Acetic acid odor Level 3: Strong acetic acid odor

[0090]

[Table 1] As is clear from the table, in the filter material of the comparative example in which activated carbon and ester plasticizer coexist, the amount of acetic acid produced is large and the odor level is also high. On the other hand, in the filter materials obtained in the examples, the production amount of acetic acid can be significantly suppressed.

[Brief description of drawings]

FIG. 1 is a schematic side view showing an addition device.

[Explanation of symbols]

 1 ... Cellulose Ester Fiber Tow 2 ... Supply Roller 3 ... Casing 4 ... Opening Adjustment Plate

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Nobuyuki Ohji 3-3-31-626, Nankochu, Suminoe-ku, Osaka

Claims (13)

[Claims] 1. A filter material comprising cellulose ester fibers, an adsorbent, and a thermoplastic resin having hot melt adhesiveness. 2. The filter material according to claim 1, wherein the melting point of the thermoplastic resin is 50 to 200 ° C. 3. The thermoplastic resin has an average particle diameter of 10 to 500.
The filter material according to claim 1, which is a particulate material having a diameter of μm. 4. The filter material according to claim 1, wherein the adsorbent is activated carbon. 5. The filter material according to claim 1, wherein a thermoplastic resin is attached to activated carbon as an adsorbent. 6. The filter material according to claim 1, which contains 1 to 200 parts by weight of an adsorbent and 0.5 to 50 parts by weight of a thermoplastic resin powder, based on 100 parts by weight of cellulose ester fiber. 7. A cellulose ester fiber bundle, a powdery granular activated carbon contained in the fiber bundle, and a powdery granular material having hot melt adhesiveness for adhering the cellulose ester fiber to hold the powdered granular activated carbon on the fiber bundle. Rod-shaped filter material made of thermoplastic resin. 8. A powdered granular activated carbon having a specific surface area of 200 to 4000 m ² / g and 25 to 150 parts by weight, and a granular thermoplastic resin of 5 to 25 parts by weight per 100 parts by weight of a cellulose acetate fiber bundle. 7. The filter material according to 7. 9. A tobacco filter comprising a rod-shaped filter material composed of a cellulose ester fiber, an adsorbent, and a thermoplastic resin having a hot melt adhesive property. 10. A method for suppressing the generation of an acidic odor component by allowing an adsorbent and a thermoplastic resin having hot melt adhesiveness to coexist in a cellulose ester fiber bundle. 11. A step of adding an adsorbent and a thermoplastic resin in the form of powder and granules having hot melt adhesiveness to the tow of cellulose ester fiber, and a tow containing the adsorbent and the thermoplastic resin is wrapped with a wrapping paper to form a rod. A filter material including a molding step of molding, a heat treatment step of heating the rod to melt at least the surface of the thermoplastic resin after the molding step or the molding step, and a cooling step of cooling the rod after the heat treatment step. Manufacturing method. 12. A tow composed of crimped cellulose ester fibers having a crimping degree of 10 to 50 per inch is opened into a width of 150 to 450 mm, and 100 to parts by weight of the tow is opened. 11. 10 to 150 parts by weight of activated carbon and 1 to 25 parts by weight of a granular thermoplastic resin are added.
A method for producing the described filter material. 13. Cellulose ester fiber 3,0 having a fineness of 1 to 10 denier and a crimp degree of 5 to 75 per inch.
Width of 10 tow composed of 0 to 1,000,000
Opening process of opening to 0-500 mm, opened tow 10
50 to 100 parts by weight of activated carbon and 0 to 7 parts by weight of a granular thermoplastic resin having hot melt adhesiveness
An adding step of adding 20 parts by weight, a forming step of winding a tow containing activated carbon and a thermoplastic resin at a speed of 300 to 800 m / min with a wrapping paper to form a rod, and after the forming step or the forming step, the rod is heat treated. Then, a method for manufacturing a tobacco filter rod, comprising: a heat treatment step of melting at least the surface of the thermoplastic resin; and a cooling step of cooling the rod after the heat treatment step.