JPH0576856B2 - - Google Patents

Description

[Detailed description of the invention]

The invention relates to disposable diapers, sanitary products (e.g. tampons and sanitary napkins), wound dressings,
The present invention relates to a fibrous absorbent material having deodorizing properties for absorbing body fluids such as bandages, incontinence pads, wipes, disposable underwear, shoe insoles, etc. in particular,
This fibrous absorbent material contains crystalline siliceous molecular sieves to improve deodorizing properties. Fibrous absorbents have been known for quite some time;
It contains a large number of fibers arranged together to absorb and retain body fluids. Body fluids retained in these absorbers emit a strong unpleasant odor. Odors emitted from body fluids are produced by a wide variety of compounds that are produced within the body, such as excreta, menstrual fluids, and sweat, that either leave the body or exude from wounds, and /or may be generated by the action of microorganisms on such body fluids. These odors can be produced by ammonia and ammonium compounds, amines, lower carboxylic acids or esters such as isovaleric acid, aldehydes, sulfur compounds, and the like. The threshold concentration of many of these odor-producing compounds for the human sense of smell is relatively low, e.g., often a few ppm by volume in air.
(1/1,000,000). For example, ammonia can generally be detected at less than 40 parts per billion by volume, hydrogen sulfide at about 1 ppb, and isovaleric acid at less than about 100 ppb. In the past, various proposals have been made to reduce these odors, such as the use of fragrances to mask the odors that may emanate from the absorbent body. Other proposals include the use of substances that remove odor-emitting compounds. Odor emitting compounds can be removed by several mechanisms. For example, chemically reacting an odor emitting substance to produce a non-odor emitting and/or non-volatile compound by chemical reaction, or sorption to a non-volatile substance, e.g. a solid or a liquid. I can do it. For sorbents that are particularly effective for deodorizing odors from body fluids that are characterized as having very low odor thresholds, the sorbent absorbs substantially all odor-emitting compounds in its environment. It is necessary to be able to remove it regardless of its concentration.
Therefore, the sorbent must be able to sorb the odor-emitting compounds even when they are present in trace amounts, and must be able to absorb the sorbed odor-emitting compounds even when they are nearing saturation. Must be able to hold. Methods have been proposed to use solid adsorbents to deodorize fibrous absorbents intended for absorption of body fluids.
Silica gel, activated alumina, diatomaceous earth, Fuller's earth, and other clay minerals, as well as zeolites, have also been proposed as odor "adsorbents" alone or in combination, but are by far the least of the solid adsorbents proposed for odor control. The most common is activated carbon or activated charcoal. Unexamined Japanese Patent Application Publication No. 1973, released on June 10, 1972.
No. 70200 discloses fibrous bodies such as paper and loose fibers. First, this fibrous body is
Heat treated at 450°C for 1-100 minutes, then treated with zeolite (treated with water repellent), synthetic zeolite, activated carbon or calcium-type bentonite. Unexamined Japanese Patent Publication No. 1987- released on August 17, 1988
No. 138452 discloses a sanitary towel comprising an absorbent fabric having on its outer surface a zeolite and an ascorbic acid compound such as a sodium or potassium salt of ascorbic acid or araboascorbic acid or an acyl derivative of ascorbic acid or araboascorbic acid. ing. Preferably, the zeolite is zeolite X or zeolite Y having large pores. Another type of sanitary towel in which a deodorizing agent is coated with a water-absorbing polymer is disclosed in Japanese Patent Application Laid-open No. 56-31425, published on March 30, 1981. Deodorants are magnesium silicate, aluminum silicate, calcium silicate, silica gel, chlorella powder, chlorophyll powder, ion exchange resin powder, activated carbon or zeolite. A diaper containing molecular sieves is disclosed in European Patent Publication No. 41569, published December 16, 1981. The omatsu is constructed with a woven layer on the side that is worn adjacent to the user's skin and a zeolite-incorporated woven layer on the opposite side. This zeolite is said to be a material capable of selectively incorporating ammonium ions, such as zeolite F, W or A, synthetic gismmondine type zeolite, synthetic or natural mordenite, chabazite, filipsite or clinoptilolite. Unexamined Japanese Patent Application Publication No. 1988-1983, released on November 27, 1985.
No. 268253 discloses sanitary products made by dispersing or impregnating natural or synthetic fibers with holmite minerals. This patent discloses that the water absorption ratio of formite (e.g., sepiolite) is approximately four times that of natural zeolite, and that products manufactured using this formite absorb sweat, excreta, and odors produced by the body. It is disclosed that it can deodorize. This sanitary product can be used for diapers, sanitary napkins, tampons, towels and underwear. Unexamined Japanese Patent Publication No. 1983, released on May 31, 1982.
No. 95042 contains 20-70% by weight of activated carbon, zeolite,
Biaxially oriented sheets of polymers containing deodorizing powders such as diatomaceous earth or clay are disclosed. This stretched sheet has fine pores of, for example, 0.1-5 microns. The sheet can be filled with an absorbent to make a sanitary towel or sanitary napkin with good liquid absorption, leakage resistance, deodorizing properties, and air permeability. Unexamined Japanese Patent Application Publication No. 1983-1973 released on November 5, 1974
No. 141857 discloses a method in which two sheets of material are laminated and a deodorizing powder such as activated carbon, zeolite, ion exchange resin, carboxymethyl cellulose or polyethylene glycol is fixed between them. Zeolites and molecular sieves are incorporated into textile products for reasons other than deodorization. For example, JP-A-61-138658, published on June 26, 1985, discloses a water-impermeable urethane film for sanitary briefs or diaper covers. This film contains antimicrobial metal ions that are ion-exchanged with the zeolite. This zeolite has a specific surface area of more than 150 m ² /g and a silica/alumina ratio of less than 14. Antimicrobial ions can be silver, copper or zinc. Similarly, U.S. Pat. No. 4,525,410, issued June 25, 1985, discloses a fibrous structure in which at least a portion of the fibers are secured together at their intersections and zeolite particles are incorporated and retained within the structure. is disclosed. This zeolite has at least 150
It is necessary to have a specific surface area of m ² /g and a silica/alumina ratio of less than 14, preferably less than 11. Zeolites are ion-exchanged with silver, copper or zinc. Molecular sieves have been proposed for other odor control applications. For example, in US Pat. No. 4,437,429, the use of hydrated zeolite mixed with clay was proposed as being particularly effective for reducing odor in pet litter. The use of zeolites alone as bedding materials has generally been unsuccessful due to their poor water absorption compared to clay. In U.S. Pat. No. 4,437,429, to adsorb certain odors from animal litter using a mixture of clay and zeolite, not only is the zeolite component used in a hydrated state, but the hydrated water is initially It has been proposed that the hydration water of It is said that it is insufficient to add water to zeolite that has been previously heat treated to drive out the initial water of hydration. Generally, when zeolites are used for odor control, preferred types have been those with low skeletal Si/Al ratios and high adsorption capacity for water or other highly polar molecules such as ammonia or hydrogen sulfide. The disclosure of U.S. Pat. No. 4,437,429 somewhat specifically describes many of the so-called high-silica zeolites that are synthesized using organic templating agents such as tetraalkylammonium ions. stand out. These include ZSM-5, ZSM-11, ZSM-12 and
Includes ZSM-23. However, the preferred zeolites are the natural mineral clinoptilolite, which has a nominal framework SiO ₂ /Al ₂ O ₃ molar ratio of about 10.
US Pat. No. 4,648,977 discloses the use of high silica molecular sieves containing the silica polymorph silicalite to adsorb toxic organic substances, including mercaptans, from aqueous media for water purification. SUMMARY OF THE INVENTION The present invention provides a fibrous absorbent article for absorbing body fluids. The fibrous absorbent contains an effective amount of molecular sieves to reduce odor emission from the absorbent. The molecular sieve has at least about 90% of the skeletal tetrahedral oxide units being _SiO2 tetrahedra, and has a pore size of at least 5.5 angstroms, and has a pore size of at least 10 angstroms under standard conditions as described herein.
It consists of a crystalline silicic acid-based molecular sieve with an adsorbed water capacity not greater than % by weight. The fibrous absorbent article of the present invention substantially eliminates characteristic odors from various body fluids. Therefore, the fibrous absorbent material can be used in disposable diapers, menstrual products, trauma bandages, etc.
It is particularly attractive for bandages, incontinence pads, sanitary towels, disposable underwear, shoe insoles, handkerchiefs, etc. Crystalline silicic acid-based molecular sieve The fibrous absorbent material of the present invention contains a crystalline silicic acid-based molecular sieve. The crystalline silicic acid-based molecular sieve has at least a skeleton tetrahedral oxide unit that is a SiO ₂ tetrahedron.
90%, preferably at least about 95%, and has a sorption capacity of less than 10% by weight for water under standard conditions. Generally, the water adsorption capacity of a molecular sieve is measured based on specified temperature, vapor pressure, and time. For the purposes of the present invention, when describing water adsorption capacity, "standard conditions" refer to a temperature of 25°C;
4.6 torr of water vapor pressure and 2 hours of time.
In the case of aluminosilicate molecular sieves, those most often used in the practice of this invention are at least about 18,
For example about 35 to infinity, preferably 200 to infinity
It has a framework SiO ₂ /Al ₂ O ₃ molar ratio of 500. All of the silicic acid-based molecular sieves preferably used have at least
5.5 angstroms, preferably at least 6.2
It has a pore diameter of angstroms. Preferably, the adsorption capacity for water vapor is 6 in standard conditions.
less than % by weight. The efficiency of the molecular sieve used in the practice of the present invention does not depend on the presence of water of hydration present in the internal cavities of the microporous structure as a result of its hydrothermal production. actual,
At least a large portion, usually substantially all, of this hydrated raw water is often removed in the process of removing any pore-blocking templating agents that may be present in the synthetic form of the molecular sieve. Ru. Calcining effectively removes the organic parts. Washing with water or with solutions of caustic or dilute mineral acids is also advantageously used to remove foreign inorganic synthesis reagents from the pore system. It may also be beneficial to reduce the content of alkali metals, particularly non-zeolitic materials, ie the amount of occluded alkali metal compounds. These procedures also serve to remove hydrated raw water. Silicate-based molecular sieves suitable for use in the practice of this invention include microporous crystalline aluminosilicate or zeolite-based molecular sieves as well as so-called silica polyhedra. For the latter compositions, their crystal lattice ideally forms entirely _SiO2 tetrahedral units, but in the as-synthesized form at least trace amounts of aluminum coming from aluminum impurities in the synthesis reagents are present. Usually included. Aluminosilicate-based molecular sieves are composed of a wide variety of known crystalline zeolites. These high silica molecular sieves are either commercially available or may be prepared by known methods including direct hydrothermal synthesis or some type of crystal lattice dealumination. “High” Si/
A comprehensive review of Al zeolites and silica molecular sieves is given by E. M. Flanigen in “Broseeding of Fifth International Conference on Zeolites, Naples, 1980”: LVC Reese, Haydn,
Published in London, pp. 760-780. This paper is hereby cited as a reference. It is a critical aspect of the present invention that under standard conditions, the silicic acid molecular sieve has a water adsorption capacity of less than 10% by weight. Another critical aspect is that even if there are AlO ^- ₂ tetrahedral units in the crystal lattice, their number is much smaller than the number of SiO ₂ tetrahedral units. It has been observed that there is some correlation between the skeleton SiO ₂ /Al ₂ O ₃ ratio and the adsorption capacity for water, that is, the so-called hydrophobicity of the silicic acid molecular sieve. However, it has also been observed that in some cases, for example in the case of zeolite beta, molecular sieves with a highly siliceous crystalline framework may not be sufficiently hydrophobic or may not have the desired sorption properties. . That is, although many molecular sieves with backbone SiO ₂ /Al ₂ O ₃ molar ratios greater than about 18, particularly greater than about 35, exhibit the degree of hydrophobicity necessary for use in the present invention, some is not shown. in some cases low, i.e. less than 0.2% by weight on an anhydrous basis;
It may also be advantageous to have an alkali metal content of the molecular sieve. Regardless of the reason, the above-defined class of medium- to large-pore silicic acid-based molecular sieves is suitable for use from body fluids, preferably in a form in which the water of hydration during synthesis has been substantially removed during synthesis. It works extremely well in eliminating odors. Many synthetic zeolites prepared using organic templating agents are readily obtained in high-silica forms even from reaction mixtures in which no aluminum is intentionally added. These zeolites are extremely organophilic and include ZSM-5 (U.S. Pat. No. 3,702,886), ZSM to name a few.
-11 (US Patent No. 3709979), ZSM-35 (US Patent No. 4016245), ZSM-23 (US Patent No. 4076842)
), and ZSM-38 (US Pat. No. 4,046,859). Silica molecular sieves known as silicalite and L-silicalite have been found to be particularly suitable and preferred for use in the present invention. These substances are each covered by U.S. Patent Nos.
No. 4061724 and No. 4073865.
To the extent that the silicic acid-based sieves mentioned above are synthesized with a SiO ₂ /Al ₂ O ₃ ratio greater than 35, they are
Often suitable for use in the method of the invention to increase its degree of hydrophobicity without additional treatment. Molecular sieves that cannot be directly synthesized to have sufficiently high Si/Al ratios and/or hydrophobicity ratios can be made into organophilic zeolite products by dealumination, fluorine treatment, etc. High-temperature steam treatment of zeolite Y to make it a hydrophobic product is described in PK Maher et al.'s "Molecular Sieve Zeolite" Advanced Chemistry Series, 101, American Chemical Society, Washington, D.C.
D., 1971, 266 pages. Recently reported methods applicable to zeolite species generally involve dealumination and substitution of silicon into the dealuminated lattice sites. This method is disclosed in U.S. Pat. No. 4,503,023, issued March 5, 1985 to Skiles et al.
The treatment of zeolites with halogen or halide compounds to increase their hydrophobicity is disclosed in U.S. Pat.
No. 4569833 and No. 4297335. For the above-mentioned adsorbents, it is important that the pore system must be open so that the internal cavities of the crystals are accessible to the odorous substances. In the case of aluminosilicates and silica polyhedra made using large organic template ions such as tetraalkylammonium ions, it is necessary to remove charge-balancing organic ions and occluded template agents in order to adsorb odorants. There is. In such removal steps and mineral debris removal, raw water of hydration is also removed. Although some of the hydration water is recaptured by exposure to the atmosphere, this does not affect the general performance of the molecular sieve, i.e. the molecular sieve can be used in both hydrated and dehydrated states. can. However, the dehydrated state is generally preferred. In most of the dealumination processes described above, the raw water of dehydration is also removed and can be replaced as well if necessary. It must be pointed out that what is important is the framework SiO ₂ /Al ₂ O ₃ molar ratio. This is not necessarily the same ratio as shown in conventional wet chemical analysis.
This is especially the case when dealumination is carried out with a high temperature steam treatment, in which case the aluminum-containing tetrahedral units of the zeolite are destroyed, but the aluminum number remains at least partially within the zeolite crystals. For such zeolite products, other analytical methods such as X-rays and NMR must be utilized. One such steam-treated zeolite Y composition, LZ-10, is described in U.S. Pat. No. 4,331,694 and in U.S. Pat. is described in detail. Although it appears that benefits may be obtained by combining such molecular sieves in various proportions, each type of adsorbent has at least 10 Preferably, it is present in an amount of %. The crystalline silicic acid-based molecular sieve can be in any suitable form. Typically, molecular sieves are in their powder form, or they can be aggregated into large particles, such as from about 0.5 to 500 microns or more in bulk size. The mass can be of any other shape, such as spherical, cylindrical, free-form, etc. Binders such as silica binders or alumina binders can be used in forming the aggregates. The assembly may contain other desirable components for fibrous absorbent applications, as described later herein. Fibrous Absorbent Materials The fibrous absorbent materials include fibrous materials capable of absorbing body fluids such as menstrual fluids, urine, sweat, exudates from trauma, and the like. Various fibrous materials proposed as absorbents include wood wool.
fluff), cellulose derivatives (rayon), cotton,
Included are synthetic polymers and synthetic polymer mixtures (eg, polyester, polypropylene, nylon, polyethylene, etc.). The fibrous material can be arranged in the form of a woven or non-woven structure, which can be in the form of a batt or a woven fabric or tissue or a woven or apertured form. These structures can be formed by any convenient technique, including dry and wet techniques. The fibrous absorbent body can be a substantially single-component article or it can be a multi-component article. The particular arrangement will often be selected depending on the application and other components of the fibrous absorbent article. Examples of single-component articles include articles in which the fibrous material substantially comprises paper towels, nonwoven fabrics in the form of underwear, shoe insoles, and the like in which silicic acid-based molecular sieves are incorporated into the fibrous structure. It is composed of Multi-component articles can use layers or regions of different materials or the same material. For example, a sanitary napkin can be comprised of multiple fibrous absorbent fabrics, or a wipe can have multiple fibrous absorbent fabrics. Dissimilar components in the fibrous absorption zone can perform different functions. That is, the fibrous butt can be placed between a substantially water-impermeable outer sheet and a permeable but non-absorbent body-contacting sheet in the construction of a sanitary bandage, bandage or sanitary napkin. can. A frame for attaching the fibrous material may also be provided using a structural fabric of a stronger but possibly substantially non-absorbent material, which structural fabric is attached to the resulting fibrous absorbent body. significant strength can be given to the Other ingredients that can be included in fibrous absorbent articles include superabsorbents in the case of menstrual devices, incontinence pads, towels and diapers. Superabsorbents can be used in large quantities, often up to 10 times their dry weight.
or more water can be absorbed. Superabsorbents typically include polysaccharides, modified and regenerated polysaccharides, grafted polysaccharides, polyacrylates, polyacrylonitrile (particularly polyacrylonitrile grafted onto polyvinyl alcohol), polyvinyl alcohol, hydrophilic polyurethanes, moieties. water-swellable polymers such as hydrolyzed polyacrylamides, sulfonated polystyrenes, sulfonated polyethers, poly(alkylene oxides), and the like. The superabsorbent can be provided in any convenient form, such as fibers, spheres, film pieces, or coatings on other components in the fibrous absorbent. Other components that may be present include medicants, other absorbents or adsorbents (sodium bicarbonate, activated carbon, clay and silica gel, and zeolites X, Y, W, A, clinobutyrolite). other molecular sieves with a high degree of water sorption and/or ammonium ion sorption, such as
and mordenite, etc.). Although fragrances can be used, consideration must be given to the sorption properties of the silicic acid molecular sieve. Large molecule fragrances are generally preferred. The amount of crystalline silicic acid-based molecular sieve used in the fibrous absorbent article is sufficient to significantly reduce, if not substantially eliminate, odors from body fluids intended to be absorbed during use. It should be. That is, the amount of crystalline silicic acid-based molecular sieve desired to be incorporated can be varied depending on the use of the fibrous absorbent material. Higher amounts may be desired in applications such as diapers, where there may be a need to retain substantial odor-producing fluids, than in applications such as bandages. The silicic acid-based molecular sieve used in the fibrous absorbent material of the present invention is characterized as being very effective when used in relatively small amounts. This is due in part to the absorption activity of these molecular sieves and in part to the selectivity of the silicic acid-based molecular sieves for odoriferous compounds emanating from body fluids. For example, small amounts such as 0.1 g of silicic acid-based molecular sieves have been found to effectively remove odors from menstrual devices. The amount of silicic acid-based molecular sieve used in a fibrous absorbent article can be characterized in a variety of ways: on a per absorbent basis, on a volume basis, on an effective area basis, and the like. Due to the wide variety of fiber absorbent materials, structures and shapes as well as fiber structures, difficulties exist in establishing a perfect standard for the description of silicic molecular sieve content. Generally, however, the silicic molecular sieve content can be expressed in grams per unit volume of the fibrous structure in the uncompacted, dry state, or in grams per unit effective area (i.e., the area of the major faces of the fibrous structure). . Generally, the amount of crystalline silicic acid-based molecular sieve is per ^100cm3 of fibrous material.
at least about 0.001 g, and in some cases up to about 50 g;
Preferably it is 0.01 to 25g. The amount of crystalline silicic acid molecular sieve is often about 0.05g per ^100cm3 capacity.
It is between 10g. Typically, the silicic acid-based molecular sieve is used in an amount of about 0.01 to 25 g per 100 cm ² of effective area, e.g.
Supplied in amounts of 0.05 to 10g. For various applications, such as menstrual devices, the crystalline silicic acid-based molecular sieves are typically used at approximately
0.01 to 10g for diapers, about 0.05 to 50g per diaper, 1 pad for shoe pads
Use an amount of about 0.05 to 10g per piece. The crystalline silicic acid-based molecular sieve can be incorporated into the fibrous absorbent body in any suitable manner. For example, the molecular sieve can be loosely dispersed in a batt or tissue containing fibrous material. However, it is generally preferred that the molecular sieve is sufficiently immobilized within the fibrous absorbent body so that it does not easily migrate into the body. For example, a molecular sieve can be held in a fibrous absorbent body within a fluid permeable container through which the molecular sieve cannot pass. That is, the molecular sieve can be placed between two heat sealed sheets of permeable thermoplastic. The sheet can be perforated with small holes to achieve the desired permeability.
A particularly attractive means for immobilizing silicic acid-based molecular sieves in fibrous absorbent materials is to place the molecular sieve between two layers of absorbent tissue or fabric;
The layers are then bonded together mechanically, for example by needle punching or fixing; by gluing, for example using latex; or by heat sealing. The molecular sieve-containing composite can be easily manipulated, including cutting and forming and incorporating into fibrous absorbent articles. Another means for providing the molecular sieve is in a material in the form of a polymeric film or paper intended to contain a fibrous material or to be incorporated into a fibrous absorbent, e.g. %, so to speak, about 1 to 70% by weight, such as about 5 to 70% by weight. Alternatively or additionally, molecular sieves can be similarly incorporated into the fibrous material produced from the polymeric melt and/or any superabsorbent used. The molecular sieve can also be applied by using an adhesive on at least a portion of the fibrous absorbent body (e.g. lining, fibrous material, structural element, etc.) or by using a molecular sieve and a thermoplastic material (e.g. lining, fibrous material, structural element, etc.). structural elements, etc.) can even be incorporated by contacting the thermoplastic material while it is at a sufficiently high temperature that it is tacky. FIG. 1 illustrates a sanitary napkin having a textile overlay 12. FIG. FIG. 2 is a sectional view showing the structure of the napkin 10. In Figure 2,
The textile overlay 12 is a moisture-permeable nonwoven fabric with a moisture-permeable layer 14 directly therein that surrounds the sides and bottom of the sanitary napkin. Included within the volume defined by the textile overlay 12 and the moisture impermeable layer 14 is a fibrous batt 16 that serves to absorb liquid. Particles of superabsorbent 18 are also shown within vat 16. As shown, the nonwoven fabrics 20 and 22 form a sandwich structure, shown in the middle of the butt 16, and are fluid permeable. There is a silicic acid based molecular sieve dispersed between the fabrics 20 and 22. Cloths 20 and 22 are secured together by latex. In another embodiment the cloth 20
and 22 can be located directly adjacent the bottom or top of the interior of the napkin 10. EXAMPLES The present invention will be explained below with reference to Examples. For example, body odor from menstrual fluids can contain lower carboxylic acids and amines. Example 1~
No. 19 describes the effectiveness of siliceous molecular sieves for removing isovaleric acid and triethylamine, which are odorous components typically present in menstrual fluid. For Examples 1-20, a number of higher silica-aluminosilicates and silica polymorphs were exposed to and adsorbed in a reproducible and consistent manner to various odorous substances. The absolute or relative amount of odor was measured. A 40 ml screw-top vial with a Teflon-lined silicone rubber septum was used for this experiment. The glass bottle had a capacity of 43.5±0.1 ml. The activated charcoal adsorbent used was 70/80 mesh chromatographic grade from Analab, Inc., Hamden, Conn., USA, under the trade name "Anasorb." The adsorbent of interest was weighed into a glass bottle and the bottle was capped. The adsorbate was added to a sealed glass vial using a Hamilton syringe. The samples were shaken by hand to mix the liquid/solid/vapor phases, and the gas phase at the top of the vial was analyzed by gas chromatography within 5 to 20 minutes after weighing and mixing. To determine the maximum vapor concentration of a volatile test compound in air, the pure compound was placed in a 43.5 ml glass bottle and stored for at least 1 hour before analysis. Generally, 2 mL from the top of a 43.5 ml glass bottle.
Microliters were analyzed. Two microliters of room air was injected to maintain a constant pressure. Before and after each sample injection, the syringe needle was placed under vacuum (estimated at a pressure of <5 x 10 ^-3 Torr or less) at 200°C.
into a syringe washer. A 100 watt light bulb was placed 1 to 2 inches above the syringe as a heat source. This was done to eliminate possible contamination from vapor molecules adsorbed on the Teflon portion of the syringe. Vacuum heating was performed for approximately 5 minutes prior to use. Analysis of the room air after this cleaning operation showed that the syringe was free of contamination. A gas chromatographic analysis method was used to measure the concentration of odor components in the upper part of the sample glass bottle.
The column is a 0.32 mm by 30 meter internal diameter fused silica adsorption capillary containing a 1 micron internal coating of polyethylene glycol as the adsorbent.
A flame ionization detector was used to measure retention times. Oven conditions were 50℃ for 4 minutes, then
The temperature was increased to 150°C at a rate of 10°C/min. Example 1 (a) 10 microliters of isovaleric acid was placed in an empty 43.5 ml glass bottle with a lid and the vapor in the top was measured according to the test method described above and was found to be present at a concentration of 668 ppm. The retention time is
It was 4.83 minutes, with another small peak at 4.22 minutes. (b) Add 0.5 grams of sodium bicarbonate to the glass bottle containing the isovaleric acid used in (a) above. The concentration of isovaleric acid at the top of the glass bottle is
It was found that the concentration had decreased to 2.2ppm.
The peak at 4.22 minutes seen in (a) still exists,
Furthermore, new peaks appeared at 4.87 minutes, 6.36 minutes, 6.61 minutes, and 6.94 minutes. (c) Add activated silicalite and zeolite to the glass bottle containing isovaleric acid used in (a) above.
0.5 grams of an equal parts mixture of LZ-10 was added.
It was found that the concentration of isovaleric acid at the top of the glass bottle had decreased to below the limit of approximately 0.82 ppm determined by the gas chromatography glass detector.
The peak at 4.22 minutes disappeared and no new peaks appeared. Examples 2-9 Eight sorbents were tested for their ability to deodorize spaces above triethylamine and various animal and human waste common components. To conduct the test, 500 mg of adsorbent solids was placed in a 43.5 ml glass bottle and enough triethylamine was added to give a weight loading of 4.37% triethylamine. For comparison, triethylamine was placed in a glass bottle without adsorbent. The vapor at the top of the vial was analyzed in the same manner as described above. The adsorbent designated as LZ-20 in Example 2 and subsequent examples is a vaporized zeolite Y prepared in substantially the same manner as used to prepare LZ-10, except that the steaming conditions are less severe. It is a stabilized type, and its water adsorption capacity under standard conditions is approximately 10% by weight, and its sodium content (Na ₂ O
) was 0.2% by weight (calculated as anhydride).
LZ-105-5 for Example 9 and subsequent examples
The adsorbent designated as ZSM was prepared without the presence of an organic templating agent and obtained by a method that produced a zeolite with a SiO ₂ /Al ₂ O ₃ molar ratio of about 36.7 and a Na ₂ /Al ₂ ratio of 1.19. -There are 5 types of zeolites. The adsorbent composition of Example 5 was a mixture of equal parts by weight of LZ-10 and silicalite. The analysis results are shown in the table below.

[Table] Example 10 Various weight percentages of loading into an equal parts composition of LZ-10 and silicalite as residual headspace concentration
In order to determine the effect of isovaleric acid and butyl mercaptan (butanethiol), increasing amounts were used in combination. The results were as follows.

TABLE Examples 11-18 The same tests as Examples 2-9 were performed on a number of other materials. The results were as follows.

[Table] *=Equivalent parts by weight Example 19 The samples obtained in Examples 11 to 18 were left at room temperature with the lids closed, and retested 24 hours later. The following results were obtained.

[Table] Example 20 In order to confirm that certain high silica molecular sieves lacking the necessary degree of hydrophobicity do not have the quality as adsorbents for use in the present invention, the framework SiO ₂ /Al ₂ O ₃ molar ratio was is 25.4, and the water adsorption capacity under standard conditions is 14.28.
% by weight of zeolite beta was contacted with isovaleric acid. A subjective "sniff" test revealed that a significant amount of odor from isovaleric acid remained after contact with the adsorbent. Example 21 Sanitary napkin (menstrual band) obtained in the market
[Trade name "STAYFREE" available from Johnson & Johnson] during menstruation,
worn by women. When the sanitary napkin was removed, a peculiar odor was detected, although the sanitary napkin was odorless. A mixture of activated silicalite and equal parts by weight of zeolite LZ-10 was sufficiently spread over the soiled area to cover the soiled area and no odor was detected. Example 22 Two nonwoven sheets of cellulose were incorporated into a laminate sandwich with a relatively uniform distribution of silicic acid-based molecular sieves. Each sheet was approximately 1 mm thick, approximately 12 cm wide, and approximately 25 cm long. These sheets were closely adhered together using polyester to form a single sheet approximately 2 mm thick. This sheet contained about 1 g of a mixture of equal weight parts of activated silicalite and zeolite LZ-10. The sheet was folded in half and placed under the top layer of a commercially available sanitary napkin (trade name "STAYFREE" available from Johnson & Johnson) and worn by the woman during her menstrual period. After use, the napkin had no detectable odor. The present invention includes the following embodiments. 1. The fibrous material and skeletal tetrahedral oxide units formed into a structure suitable for absorbing body fluids are at least about 90% _SiO2 tetrahedra, have a pore size of at least about 5.5 angstroms, and under standard conditions to
A fibrous absorbent material for absorbing body fluids, comprising an amount of crystalline siliceous molecular sieve having a water absorption capacity of 10% by weight or less and effective for reducing the odor of body fluids. 2. The fibrous absorbent material according to aspect 1, wherein the crystalline siliceous molecular sieve is at least partially activated. 3 The siliceous molecular sieve is 6% by weight under standard conditions.
The fibrous absorbent material according to aspect 1, which has the following water absorption ability. 4. A skeleton in which the siliceous molecular sieve is larger than 35
The fibrous absorbent material according to aspect 1, which is an aluminosilicate having a molar ratio of SiO ₂ /Al ₂ O ₃ . 5 The aluminosilicate is 200 to 500 SiO ₂ /
The fibrous absorbent material according to aspect 4, having an Al ₂ O ₃ molar ratio. 6. The fibrous absorbent material according to aspect 1, wherein the siliceous molecular sieve is made of a silica polymorph. 7 The siliceous molecular sieve has a silica polymorph and 200 to
Fibrous absorbent article according to embodiment 1, comprising a mixture with an aluminosilicate having a framework SiO ₂ /Al ₂ O ₃ molar ratio of 500. 8. The siliceous molecular sieve is composed of a mixture of a silica polymorph and a Y-type zeolite having a framework SiO ₂ /Al ₂ O ₃ molar ratio of at least 35, and the silica polymorph and Y-type zeolite are each measured under standard conditions. The fibrous absorbent material according to aspect 1, which has a water absorption capacity of 10% by weight or less. 9 the silica polymorph consists of silicalite;
The fibrous absorbent material according to aspect 8, wherein the Y-type zeolite is LZ-10. 10. The fibrous absorbent material according to claim 1, wherein the crystalline siliceous molecular sieve contains less than 0.2% by weight of an alkali metal on an anhydrous basis. 11. The fibrous absorbent material according to aspect 1, comprising about 0.01 to 50 g of the silicic acid molecular sieve per 100 cm ³ of volume of the absorbent material. 12. The fibrous absorbent material according to aspect 1, comprising 0.01 to 25 g of the siliceous molecular sieve per 100 cm ³ of the effective area of the absorbent material. 13. The fibrous absorbent material according to aspect 1, wherein the fibrous material has a nonwoven butt-like structure. 14. The fibrous absorbent material according to aspect 1, wherein the siliceous molecular sieve is dispersed in the fibrous material. 15. The fibrous absorbent material according to aspect 1, which includes the siliceous molecular sieve in a liquid-permeable structure that does not allow the siliceous molecular sieve to pass therethrough. 16 The fibrous absorbent material according to aspect 5, which is a sanitary product. 17. The fibrous absorbent material according to aspect 16, which is a sanitary napkin. 18 Embodiments containing about 0.01 to 10 g of siliceous molecular sieve
17. The fibrous absorbent material according to 17. 19. The fibrous absorbent article according to aspect 17, wherein two types of siliceous molecular sieves are contained in two liquid-permeable sheets having a sandwich structure located in the sanitary napkin. 20. The fibrous absorbent material according to embodiment 19, comprising a superabsorbent.

[Brief explanation of drawings]

FIG. 1 is a perspective view of a sanitary napkin. Second
The figure is a cross-sectional view of the sanitary napkin through line 2--2 of FIG.

Claims (1)

Claims: 1. A fibrous material formed into a structure suitable for absorbing body fluids and having at least about 90% of the skeletal tetrahedral oxide units being SiO ₂ tetrahedra and having a pore size of at least about 5.5 angstroms. and under standard conditions.
A fibrous absorbent material for absorbing body fluids, comprising an amount of crystalline siliceous molecular sieve having a water absorption capacity of 10% by weight or less and effective for reducing the odor of body fluids. 2. The fibrous absorbent material according to claim 1, which is a sanitary product. 3. The fibrous absorbent material according to claim 2, wherein the sanitary product is a sanitary napkin, and two types of silicic acid molecular sieves are contained in two liquid-permeable sheets having a sandwich structure located in the sanitary napkin. 4. The fibrous absorbent material according to claim 3, comprising a superabsorbent.