JP3789959B2 - Cellulose ester substance, process for producing the same and cigarette filter using the same - Google Patents

Description

【００６３】
【発明の効果】
本発明によるセルロースエステル粉体およびセルロースエステル繊維は、可塑剤や接着剤などを用いないで、単に水で湿らせた後、成形し乾燥することによって、容易にたばこフィルターをはじめとするフィルター類、不織布類、緩衝材類、錠剤類などの成形物を得ることができる。また、得られた成形物は、水崩壊性に優れるため、使用後あやまって環境中に捨てられても、雨水などの作用により、速やかに繊維状に崩壊し、環境の美観の保全に有効である。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to cellulose ester powder and cellulose ester fibers useful for producing various filters including tobacco filters, various non-woven fabrics, buffer materials, tablets and the like. Furthermore, the present invention relates to a tobacco filter that easily disintegrates or disperses by rainwater or the like even if it is discarded in the environment after smoking, and a method for producing the same.
[0002]
[Prior art]
Cellulose ester powders are commercially available in various sizes, from pellets, fibers or flakes with a long diameter of several millimeters to several centimeters to fine powders with a particle diameter of several tens of microns. .
[0003]
When forming various types of filters including tobacco filters, various nonwoven fabrics, cushioning materials, tablets, etc. from such cellulose ester powder, generally as plastic binders such as triacetin and triacetin, Ethylene glycol diacetate, triethylene glycol dipropionate, dibutyl phthalate, dimethoxyethyl phthalate, citric acid triethyl ester and the like are used.
[0004]
Various filters, various nonwoven fabrics, cushioning materials, tablets, and the like molded using the plasticizer are partially fused with each other by the plasticizer. That is, the plasticizer has a function as a binder that is randomly bonded at the bonding site of the cellulose ester powder. Therefore, when it is discarded after use, it takes a long time until the shape collapses in the environment, which not only impairs the beauty but also contributes to environmental pollution.
[0005]
Fiber bundles of cellulose ester fibers are used in the manufacture of various filters including tobacco filters, various non-woven fabrics and buffer materials. Such a fiber bundle of cellulose ester fibers is generally produced by a dry spinning method. That is, it is produced by bundling thousands to millions of fibers obtained by continuously extruding a solution obtained by dissolving a cellulose ester in a solvent from the pores of a spinneret and drying it.
[0006]
When forming various filters such as a cigarette filter, various non-woven fabrics and cushioning materials from a fiber bundle of such cellulose ester fibers, generally, as a binder between the fibers, a plasticizer such as triacetin, triethylene glycol diethylene is generally used. Acetate, triethylene glycol dipropionate, dibutyl phthalate, dimethoxyethyl phthalate, citric acid triethyl ester and the like are used.
[0007]
In various filters, various non-woven fabrics, cushioning materials and the like molded using the plasticizer, the fibers are partially fused by the plasticizer. That is, the plasticizer has a function as a binder that is randomly bonded at the bonding site of the cellulose ester fiber. Therefore, when it is discarded after use, it takes a long time until the shape collapses in the environment, which not only impairs the beauty but also contributes to environmental pollution.
[0008]
To remove tars in cigarette smoke and not impair the taste, cigarette filters composed of fiber bundles of cellulose ester are widely used. In such a cigarette filter, a plasticizer such as triacetin, triethylene glycol diacetate, triethylene glycol is used as a binder to maintain the shape of the filter plug and to obtain the hardness necessary to cut the filter tip from the filter plug. Dipropionate, dibutyl phthalate, dimethoxyethyl phthalate, citric acid triethyl ester and the like are used.
[0009]
In the filter plug formed using the plasticizer, the fibers are partially fused by the plasticizer. That is, the plasticizer has a function as a binder that is randomly bonded at the bonding site of the cellulose ester fiber. Therefore, when it is discarded after use, it takes a long time until the shape collapses in the environment, which not only impairs the beauty but also contributes to environmental pollution.
[0010]
On the other hand, a paper-made tobacco filter made of wood pulp processed into a crepe shape and a tobacco filter made of a regenerated cellulose fiber bundle are also known. These filters have a slightly higher disintegration property when wet compared to a filter made of a fiber bundle of cellulose ester, and can reduce environmental pollution to some extent. However, the taste of tobacco is inferior, the selective removability of phenols required as a filter is extremely low compared to cellulose esters, and the filter hardness is low compared to cellulose esters at the same pressure loss.
[0011]
Japanese Patent Application Laid-Open No. 56-24151 discloses a filter including cellulose acetate fibers and heat-fusible fibers for heat-sealing these fibers at intersections. As the heat-fusible fiber, a fibrillated polyolefin fiber or the like is used, and the amount used is 25 to 50% by weight with respect to cellulose acetate. Such a filter has substantially no disintegration in water because cellulose acetate fibers are three-dimensionally joined at a number of intersections by heat-sealing fibers.
[0012]
JP-A-50-75223, which corresponds to US Pat. No. 4,111,117, is selected from the group consisting of high-boiling polyols and polyesters, polyamides and polyesteramides, and is soluble in water and water-soluble or water-soluble. It is disclosed that a cigarette filter is produced by adhering cellulose fibers using an adhesive composition composed of a dispersible polymer.
[0013]
WO 93/24685 relates to a biodegradable cigarette filter composed of cellulose ester fibers and photoactive metal oxides, a filter bundle in which the fibers are bound by a water-soluble binder, and the filter bundle portion using a wrapping paper. A filter rod (cigarette filter) composed of a water-soluble adhesive for covering and fixing is disclosed.
[0014]
On the other hand, the filter rod is manufactured by winding a fiber bundle of cellulose ester fibers at a high speed of, for example, about 400 m / min using a wrapping paper. For this reason, the manufacture of the filter rod requires high-speed workability for winding the fiber bundle smoothly at high speed.
[0015]
[Problems to be solved by the invention]
Accordingly, an object of the present invention is to provide a fiber bundle of cellulose ester fibers that is excellent in disintegration when wet and can reduce environmental pollution.
[0016]
Another object of the present invention is to provide a filter rod (cigarette filter) that is excellent in disintegration when wet and can reduce environmental pollution, and a method for producing the same.
[0017]
Still another object of the present invention is to provide a filter rod (tobacco filter) that can be easily disintegrated or dispersed by water such as rainwater and that does not impair the aesthetics of the environment even if discarded after smoking, and a method for producing the same. There is.
[0018]
[Means for Solving the Problems]
As a result of intensive studies to achieve the above object, the inventors of the present invention develop an adhesive force by mutually shaping at least a part of the surface of the cellulose ester powder or fiber after being wetted with water and then drying. Using a cellulose ester fiber bundle hydrolyzed to the point, instead of the cellulose ester plasticizer, a molded product prepared by wetting with water, molding and drying rapidly disintegrates by contact with water. The present invention has been completed.
[0019]
That is, the cellulose ester powder of the present invention and the fiber bundle of cellulose ester fiber until the fiber bundle of cellulose ester fiber obtained in accordance with a conventional method develops an adhesive force by allowing water to act and then drying. It can be obtained by hydrolyzing at least a part of the fiber surface.
[0020]
DETAILED DESCRIPTION OF THE INVENTION
Examples of the cellulose ester include organic acid esters such as cellulose acetate, cellulose butyrate, and cellulose propionate; mixed acid esters such as cellulose acetate propionate, cellulose acetate butyrate, cellulose acetate phthalate, and cellulose nitrate acetate; and poly Examples include cellulose ester derivatives such as caprolactone-grafted cellulose ester. These cellulose esters can be used alone or in admixture of two or more.
[0021]
The average degree of polymerization of the cellulose ester is, for example, about 50 to 900, preferably about 200 to 800. The average degree of substitution of the cellulose ester is, for example, about 1.5 to 3.0.
[0022]
Preferred cellulose esters include organic acid esters (for example, organic acid esters having about 2 to 4 carbon atoms), particularly cellulose acetate. Although the acetylation degree of cellulose acetate is often about 43% to 62%, a cellulose ester having an acetylation degree of about 30 to 50% is excellent in biodegradability. Therefore, the acetylation degree of cellulose acetate can be appropriately selected within a range of about 30 to 62%.
[0023]
The fiber of the cellulose ester includes various additives such as kaolin, talc, diatomaceous earth, quartz, calcium carbonate, barium sulfate, titanium oxide, alumina and the like; alkaline earth metal salts such as calcium and magnesium. A heat stabilizer such as, a colorant, an oil agent, a yield improver, and the like. Moreover, the degradability of powders and fibers can be enhanced by including an environmental degradation accelerator (biodegradation accelerator) such as citric acid, tartaric acid, malic acid, and a photodegradation accelerator such as anatase-type titanium oxide. .
[0024]
In addition, the cellulose ester fiber often contains a whiteness improver such as titanium oxide, preferably anatase type titanium oxide. In many cases, the average particle diameter of titanium oxide is, for example, about 0.1 to 10 μm, preferably about 0.2 to 5 μm. The content of titanium oxide is 0.05 to 2.0% by weight, preferably 0.1 to 1% by weight, more preferably about 0.2 to 0.8% by weight, based on the whole cellulose ester. It is often about 4 to 0.6% by weight.
[0026]
The fineness of the cellulose ester fiber is 1 to 16 denier, preferably 1 to 10 denier, more preferably about 2 to 8 denier. The cellulose ester fiber may be a non-crimped fiber, but is preferably a crimped fiber. The degree of crimp of the crimped fibers is, for example, about 5 to 75, preferably 10 to 50, and more preferably about 15 to 50 per inch. The degree of crimp of the fiber is often about 20-50 per inch. Further, a crimped fiber that is uniformly crimped is often used. When used in a cigarette filter, when crimped fibers are used, it is possible to obtain a filter rod having moderate ventilation resistance and suppressed channeling, and effectively bonding the fibers even if the degree of hydrolysis is small. it can.
[0027]
The cross-sectional shape of the cellulose ester fiber is not particularly limited, and may be any of, for example, a circular shape, an oval shape, an irregular shape (for example, a Y shape, an X shape, an I shape, an R shape) or a hollow shape. Also good.
[0028]
A fiber bundle composed of cellulose ester fibers can be formed, for example, by bundling about 3,000 to 1,000,000, preferably about 5,000 to 1,000,000 cellulose ester fibers. . In many cases, the fiber bundle is formed by collecting approximately 3,000 to 1,000,000 continuous fibers.
[0029]
The method for hydrolysis of the cellulose ester fiber of the present invention is not particularly limited, but can be easily hydrolyzed by contacting with an inorganic, organic alkali or acid solution.
[0030]
Examples of the alkali include sodium hydroxide, sodium carbonate, sodium hydrogen carbonate, potassium hydroxide, triethanolamine, and examples of the acid include hydrochloric acid, sulfuric acid, nitric acid, formic acid, acetic acid, malic acid, glycolic acid, and the like. These acids and alkalis are used as an aqueous solution or a mixed solution of water and a hydrophilic organic solvent. In view of safety and ease of handling, it is particularly preferable to use sodium hydroxide, sodium carbonate or sodium hydrogen carbonate as a solution of water having a suitable concentration or a mixed solution of water and a hydrophilic organic solvent.
[0031]
Examples of the hydrophilic organic solvent include alcohols such as methanol, ethanol, isopropanol, butanol, and t-butanol, 1,2-propanenediol, 1,3-propandiol, ethylene glycol, diethylene glycol, glycerin, 1, Polyhydric alcohols such as 2-butanediol, 1,3-butanediol, 1,4-butanediol, and 2,3-butanediol, ethers such as cellosolve, dioxane, and tetrahydrofuran, and mixed solvents thereof can be used. .
[0032]
Hydrolysis conditions (concentration of alkali or acid used, temperature, amount used, hydrolysis time, etc.) vary depending on the type of alkali or acid used, so it cannot be limited, but water is added to the fiber bundle after hydrolysis. After adding, molding, and drying, adjustment may be made so that both strength sufficient as a molded product and water disintegration are realized.
[0033]
The concentration of the alkali or acid used is suitably in the range of 0.01 to 10N, for example. Preferably, the range of 0.1-5N is preferable. If the concentration is too high, it becomes difficult to control the hydrolysis, and if it is too thin, a sufficient effect cannot be obtained.
[0035]
The solution showered with alkali or acid of the, by a method such as coating, was added to the powder or cellulose ester fiber of a cellulose ester, was hydrolyzed, washed, to dry Thus, wetted in water of the present invention By drying, cellulose ester fibers that express mutual adhesive strength can be obtained.
[0036]
The hydrolysis treatment with the alkali or acid solution is performed unevenly on the entire cellulose ester fiber . For example, the hydrolysis treatment should be performed non-uniformly in order to develop mutual adhesive strength by wetting with water and drying without losing the cigarette ester's original cigarette smoke filtering performance as much as possible. Can be said to be more effective.
[0037]
The cigarette filter of the present invention can be prepared by adding water to the fiber bundle or powder obtained by partial hydrolysis as described above, and winding up with a wrapping paper. Water may be added by water alone, but may be added as a mixed solution with the hydrophilic organic solvent as described above.
[0038]
In addition, the cigarette filter of the present invention adds the above-mentioned alkali or acid aqueous solution or water and a hydrophilic organic solvent solution to the normal cellulose ester fiber bundle not treated by the hydrolysis treatment of the present invention at the time of winding. and, continuing in succession, by rolling up the wrapping paper, hoisting and hydrolysis can be a can be performed at the same time.
[0039]
In the production of a cigarette filter, the method of adding water, a mixed solvent of water and a hydrophilic organic solvent, or a solution of these and an alkali or acid solution is not particularly limited as long as these solvents or solutions can adhere to the cellulose ester fiber. Then, it can be adhered to the cellulose ester fiber by a method of draining, a spraying method using a spray gun or the like, or a coating method. At this time, in the case of a fiber bundle, it is preferable to add it in the opened state.
[0040]
In the production of the cigarette filter, the addition of water, a mixed solvent of water and a hydrophilic organic solvent, or a solution of these and an alkali or acid may be performed unevenly over the entire fiber bundle of cellulose ester fibers . Non-uniform hydrolysis treatment in order to develop mutual adhesive strength by wetting with water and drying without damaging the inherent cigarette smoke filtration performance required for cigarette filters Can be said to be effective.
[0041]
The amount of the solvent, particularly water, applied to the fiber bundle of the cellulose ester fiber has a great influence on the productivity including the winding of the fiber bundle. That is, when the amount of the solvent applied to the fiber bundle is large, the strength and hardness of the filter are remarkably lowered, and winding with a wrapping paper or cutting with a cutter becomes difficult. Moreover, not only does it take time to develop the strength of the filter, but it also requires large energy for drying. On the other hand, when the amount of water applied is small, it is difficult to integrate the cellulose ester fibers. Therefore, the amount of water applied to 100 parts by weight of tow is 25 parts by weight or less, preferably 0.5 to 20 parts by weight, more preferably 1 to 15 parts by weight, and particularly 1 to 10 parts by weight. By setting the amount of water applied to the fiber bundle as described above, the filter rod (cigarette filter) can be smoothly moved even when the fiber bundle winding speed is 200 to 800 m / min, preferably about 300 to 800 m / min. Can be manufactured.
[0042]
In particular, when the fiber bundle of the cellulose ester fiber of the present invention is used, by adopting the above-described method, the cigarette filter manufacturing apparatus is equipped with water, a mixed solvent of water and a hydrophilic organic solvent, or a solution of these with an alkali or an acid. The cigarette filter can be easily produced simply by installing the addition device and a drying device for removing water and / or the solvent after the winding process or the winding process if necessary.
[0043]
【Example】
Hereinafter, the present invention will be described in more detail based on examples, but the present invention is not limited to these examples.
[0044]
Reference example 1
Degree of acetyl substitution (hereinafter DS) = 2.54, degree of polymerization (hereinafter DP) = 280, average particle size = 100 μm of cellulose acetate powder 100 g in 1 liter of 0.2N sodium hydroxide solution with stirring for 60 minutes It was immersed, washed with a large amount of water, and then dried to obtain a cellulose acetate powder whose surface was hydrolyzed.
[0045]
By uniformly adding 5 parts by weight of water to 10 parts by weight of the powder using a sprayer, the powder could be easily formed into a sheet using a hot press apparatus. When this sheet was put into water, it quickly disintegrated into powder.
[0046]
Reference example 2
100 g of the same cellulose acetate powder as in Reference Example 1 was immersed in 1 liter of 0.5 N sodium carbonate solution for 180 minutes with stirring, washed with a large amount of water, dried, and hydrolyzed on the surface of cellulose acetate. A powder was obtained.
[0047]
By uniformly adding 5 parts by weight of water to 10 parts by weight of the powder using a sprayer, the powder could be easily formed into a sheet using a hot press apparatus. When this sheet was put into water, the shape quickly collapsed into a powder form.
[0048]
Reference example 3
A cellulose acetate flaky powder whose surface was hydrolyzed was obtained in the same manner as in Reference Example 1 except that the cellulose acetate powder was flakes having a major axis of about 5 mm and a minor axis of about 1 mm. .
[0049]
By uniformly adding 5 parts by weight of water to 10 parts by weight of the powder using a sprayer, the powder could be easily formed into a sheet using a hot press apparatus. When this sheet was put into water, it quickly disintegrated into flakes.
[0050]
Reference example 4
Cross-sectional shape Y-shaped, 4 denier filament bundled total denier 43,000 denier cellulose acetate crimped fiber bundle 100g (crimp number 26 / 25mm) immersed in 1L of 0.2N sodium hydroxide aqueous solution for 60 minutes Then, it was washed with a large amount of water and then dried to obtain a fiber bundle of cellulose acetate fibers whose surface was hydrolyzed.
[0051]
Two fiber bundles that have been opened are stacked so that the fiber direction is perpendicular, and 5 parts by weight of water is uniformly added to the fiber bundle by 10 parts by weight using a sprayer. A mesh-like sheet could be obtained. When this sheet was put into water, the shape quickly collapsed.
[0052]
Reference Example 5
The fiber bundle of cellulose acetate fiber hydrolyzed on the surface obtained in Reference Example 4 is opened to a width of 25 cm, 15 parts by weight of water is sprayed on 100 parts by weight of the fiber bundle, and the fiber bundle is sent to a paper roll device. The filter was rolled up with a web and excess moisture was removed by heat drying, and then cut to a length of 25 mm to obtain a tobacco filter chip.
[0053]
Reference Example 6
The fiber bundle of cellulose acetate fiber hydrolyzed on the surface obtained in Reference Example 4 was opened to a width of 25 mm, and a mixed solution of 1,2-propanediol and water (weight ratio = weight ratio = 100 parts by weight of the fiber bundle). 1: 1) 20 parts by weight were sprayed, the fiber bundle was sent to a paper roll device, the filter was wound up with a web, and excess water was removed by heating and drying, and then cut to a length of 25 mm to obtain a tobacco filter chip.
[0054]
Example 1
The same crimped fiber bundle of cellulose acetate as in Reference Example 4 is opened to a width of 25 mm, and 10 parts by weight of 1N sodium hydroxide aqueous solution is sprayed on 100 parts by weight of the fiber bundle. The paper was wound up with a paper roll and excess water was removed by heating and drying, and then cut to a length of 25 mm to obtain a tobacco filter chip.
Example 2
The same crimped fiber tow of cellulose acetate as in Reference Example 4 was opened to a width of 25 mm, and a mixed solution of 1,2-propanediol and 1N aqueous sodium hydroxide solution (weight ratio = 1: 1) with respect to 100 parts by weight of the fiber bundle. 1) 20 parts by weight was sprayed, the fiber bundle was sent to a wrapping machine, the filter was wound up with a web, and excess moisture was removed by heating and drying, and then cut to a length of 25 mm to obtain a tobacco filter chip.
[0055]
Comparative Examples 1-3
Triacetin (Comparative Example 1), triethylene glycol diacetate (Comparative Example 2), and triethylene glycol propionate (Comparative Example 3), which are plasticizers of cellulose acetate, are used as binders in place of the 1N aqueous sodium hydroxide solution. Except for the above, a tobacco filter chip was obtained in the same manner as in Example 7.
[0056]
When the filter hardness and the underwater disintegration property of the tobacco filter chips obtained in Reference Examples 5-6, Examples 1-2, and Comparative Examples 1-3 were evaluated, the results shown in Table 1 were obtained. The test sample was conditioned by leaving it to stand for 24 hours in an atmosphere having a temperature of 20 ° C. and a relative humidity of 65%, and was subjected to the test.
[0057]
[Filter hardness]
A load was applied to a 90 mm long filter with a cylindrical weight having a diameter of 12 mm and a weight of 300 g, and the dent amount of the filter after 10 seconds was evaluated with 0.1 mm as 1. The practical value of the filter hardness in the measurement method is 10.0 or less.
[0058]
[Underwater disintegration test]
The filter chip cut to 25 mm is put into 500 ml of water in a beaker, and stirred with a magnetic stirrer so that the height of the vortex center is 3/4 of the highest liquid level. The shape of the filter chip was visually observed, and the disintegration was judged according to the following criteria.
[0059]
Excellent: Disintegrates quickly into cotton.
[0060]
Good: Partially disintegrates in a cotton-like shape.
[0061]
Impossible: Keep the original shape without collapsing.
[0062]
[Table 1]

[0063]
【The invention's effect】
The cellulose ester powder and the cellulose ester fiber according to the present invention can be easily damped with water without using a plasticizer or an adhesive, and then molded and dried to easily filter tobacco filters and the like, Molded articles such as non-woven fabrics, buffer materials, and tablets can be obtained. In addition, since the obtained molded product is excellent in water disintegration property, even if it is abandoned after use and thrown into the environment, it is rapidly disintegrated into fibers by the action of rainwater, etc. is there.

Claims (3)

A filter that has a filter hardness of 9 mm or less and excellent water disintegration without using an adhesive or a plasticizer by non-uniformly hydrolyzing the surface of a normal cellulose ester fiber bundle not treated by hydrolysis rod. By adding an alkali or acid aqueous solution or water and a hydrophilic organic solvent solution to a normal cellulose ester fiber bundle that has not been treated by hydrolysis treatment, and subsequently continuously winding up with a wrapping paper, hydrolysis and winding are performed. The method of obtaining the filter rod of Claim 1 obtained by performing simultaneously. 3. The method according to claim 2, comprising a step of opening a crimped fiber of cellulose ester and a step of removing water from the filter rod.