JPH0742101B2 - Submicron type A zeolite and method for producing the same - Google Patents

Description

TECHNICAL FIELD The present invention relates to a novel submicron type A zeolite having a small particle size, a method for producing the type A zeolite, and an antibacterial zeolite using the type A zeolite.

[Conventional technology]

In recent years, zeolite has been kneaded into resins.
At that time, the zeolite having a small particle size has good dispersibility in the resin, pinholes are unlikely to occur in the kneaded resin, which is advantageous when used as a film, and when the fiber is used, yarn breakage occurs. There are advantages such as difficulty. Further, zeolite having a small particle size has an advantage that the ion exchange rate is fast. Therefore, a method for producing fine zeolite has been proposed.

For example, a method of synthesizing from a natural material (Japanese Patent Laid-Open No. 52-42484, etc.) and a method by mechanical shearing (Japanese Patent Laid-Open No. 50-70289, etc.) are known. However, in any of the methods, there is a problem that the obtained zeolite has a large variation in particle size. Further, a manufacturing method (back Japanese Patent Publication No. 58-54088, etc.) without back mixing at the time of preparing a slurry has been proposed. The zeolite obtained by this method has a fine particle type of 1 μm or less. Therefore, the particle size was satisfactory. However, when the antibacterial zeolite obtained by substituting the metal ion in the zeolite obtained by the method with the antibacterial metal ion is kneaded into the resin, the resin is discolored,
There is a drawback that the degree of discoloration increases with time.

[Problems to be solved by the invention]

Therefore, an object of the present invention is to provide a fine A-type zeolite having a particle size of 1 μm or less, which is used as an antibacterial zeolite,
It is an object of the present invention to provide an A-type zeolite in which the kneaded resin does not discolor and the degree of discoloration does not increase with time.

[Means for solving problems]

The present invention has a SiO ₂ / Al ₂ O ₃ (molar ratio) of 2.0 or more and a maximum particle size of 0.4 μm measured by an electron microscope.
The following relates to a submicron type A zeolite.

The present invention will be described below.

The feature of the submicron A-type zeolite of the present invention is that SiO ₂ /
Al ₂ O ₃ (molar ratio) is 2.0 or more, preferably 2.1 to 2.5, the maximum particle size measured by an electron microscope is 0.4μ.
It is m or less. That is, the maximum particle size of the zeolite of the present invention is 0.4 μm, and usually 0.05 to 0.4 μm. The zeolite of the present invention has the same properties as the A type zeolite normally has.

The method for producing the A-type zeolite of the present invention will be described below. That is, the zeolite of the present invention comprises: (a) a step of preparing a raw material slurry containing an aluminum compound, a silicon compound and an alkali metal compound, (b) a temperature of 40 ° C. or lower to hold the raw material slurry to generate zeolite nuclei It can be produced by a production method including a step, and (c) a step of holding a slurry containing the zeolite nuclei at a temperature equal to or higher than the zeolite nucleation temperature to grow zeolite crystals.

As the raw material slurry, one containing an aluminum compound, a silicon compound and an alkali metal compound is used. Examples of the aluminum compound include aluminum hydroxide, sodium aluminate, and alumina gel. Examples of the silicon compound include sodium silicate and colloidal silica. Further, examples of the alkali metal compound include sodium hydroxide and potassium hydroxide. Furthermore, the raw material slurry contains SiO ₂ / Al ₂ O ₃ (molar ratio).
1.6 to 2.5, preferably 1.8 to 2.2, H ₂ O / Al ₂ O ₃ (molar ratio) of 50 to 160, preferably 80 to 130, M ₂ O / Al ₂
O ₃ (molar ratio) (M is an alkali metal such as sodium,
It is preferred that potassium) is 2.98 to 8.0, preferably 3.6 to 6.5.

In the present invention, the raw material slurry is maintained at a temperature of 40 ° C or lower, preferably 15 to 35 ° C to generate zeolite nuclei. The holding time depends on the temperature and the reaction scale, but it is suitable to be, for example, 3 to 48 hours, preferably 5 to 24 hours. During the holding, the slurry can be stirred by a conventional method.

Next, the slurry containing zeolite nuclei is maintained at a temperature equal to or higher than the above-mentioned zeolite nucleation temperature.
The holding can be performed, for example, at 35 to 85 ° C when the zeolite nucleation temperature is 35 ° C. The holding time depends on the temperature and the reaction scale, but is, for example, 5 to 48
It is suitable to set the time, preferably 10 to 24 hours.
Further, during the holding, the slurry can be stirred by a conventional method.

The submicron A-type zeolite thus obtained can be made into a product by separating from the slurry by a conventional method, washing with water, drying and the like.

The submicron type A zeolite of the present invention has the general formula
Displayed as XM ₂ O ・ Al ₂ O ₃・ YSiO ₂・ ZH ₂ O. Here, M represents an ion-exchangeable ion, which is an alkali metal ion. X and Y represent the respective metal oxides, silica coefficient, Z represents the number of crystal water, X is 0.9 to 1.1, Y
Is 2.0 to 2.5 and Z is 0 to 5.

The submicron A-type zeolite of the present invention obtained as described above can be used in various fields in which fine A-type zeolite is used, such as resin additives and fillers.

Further, the submicron A-type zeolite of the present invention can be used as an antibacterial zeolite in which a part or all of the ion-exchangeable ions in the zeolite are replaced with antibacterial metal ions. The submicron A-type zeolite of the present invention can also be used as an antibacterial zeolite in which some or all of the ion-exchangeable ions in the zeolite are replaced with ammonium ions and antibacterial metal ions.

These antibacterial zeolites of the present invention are those obtained by substituting a part or all of the ion-exchangeable ions in the submicron type A zeolite, such as sodium ions and potassium ions, with ammonium ions and / or antibacterial metal ions. Is. Examples of antibacterial metal ions include:
Silver, copper, zinc, mercury, tin, lead, bismuth, cadmium,
Mention may be made of chromium or thallium ions, preferably silver, copper or zinc ions.

From the viewpoint of antibacterial property, it is suitable that the antibacterial metal ion is contained in the zeolite in an amount of 0.1 to 15%. Silver ion 0.1 to 15% and copper ion or zinc ion 0.1 to 8%
The antibacterial zeolite contained is more preferable. On the other hand, ammonium ion can be contained up to 20% in the zeolite, but the content of ammonium ion in the zeolite is 0.5 to 5%, preferably 0.5 to 2% is effective in discoloring the zeolite. It is suitable from the viewpoint of preventing In this specification,% means weight% on a 110 ° C. dry basis.

The method for producing the antibacterial zeolite of the present invention will be described below.

The antibacterial zeolite of the present invention is prepared by contacting thelite with a mixed aqueous solution containing antibacterial metal ions such as ammonium ions and silver ions, copper ions, and zinc ions prepared in advance, and the ion-exchangeable ions in the zeolite as described above. Replaces ions. Contact is at 10 to 70 ° C, preferably
It can be carried out at 40 to 60 ° C. for 3 to 24 hours, preferably 10 to 24 hours by a batch system or a continuous system (for example, a column method). The pH of the mixed aqueous solution is 3 to 10, preferably 5 to 7.
It is appropriate to adjust to. By this adjustment, it is possible to prevent precipitation of silver oxide or the like on the zeolite surface or in the pores, which is preferable. Further, each ion in the mixed aqueous solution is usually supplied as a salt. For example, ammonium ions include ammonium nitrate, ammonium sulfate, ammonium acetate, ammonium perchlorate, ammonium thiosulfate, and ammonium phosphate, and silver ions include silver nitrate, silver sulfate, silver perchlorate, silver acetate, diammine silver nitrate, and diammine silver sulfate. Etc., copper ions are copper (II) nitrate, copper perchlorate, copper acetate, potassium tetracyanocuprate, copper sulfate, etc., zinc ions are zinc nitrate (II), zinc sulfate, zinc perchlorate,
Zinc thiocyanate, zinc acetate, etc., mercury ions are mercury perchlorate, mercury nitrate, mercury acetate, etc., tin ions are tin sulfate, etc., lead ions are lead sulfate, lead nitrate, etc., bismuth ions are bismuth chloride, Cadmium ions such as bismuth iodide are cadmium perchlorate, cadmium sulfate, cadmium nitrate, cadmium acetate, etc.Chromium ions are chromium perchlorate, chromium sulfate, ammonium sulfate chromium, chromium nitrate, etc. Thallium, thallium sulfate, thallium nitrate, thallium acetate, etc. can be used.

The content of ammonium ions and the like in the zeolite can be appropriately controlled by adjusting the concentration of each ion (salt) in the mixed aqueous solution. For example, when the antibacterial zeolite contains ammonium ion and silver ion,
The ammonium ion concentration in the mixed aqueous solution is 0.2 M / l ~
By adjusting the 2.5 M / l silver ion concentration to 0.002 M / l to 0.15 M / l, the ammonium ion content is 0.5 to 5%,
An antibacterial zeolite having a silver ion content of 0.1 to 5% can be obtained. In addition, antibacterial zeolite is copper ion,
When containing zinc ions, the copper ion concentration in the mixed aqueous solution is 0.1 M / l to 0.85 M / l, and the zinc ion concentration is 0.15 M / l to
By setting 1.2 M / l, the copper ion content is 0.1 ~
An antibacterial zeolite having 8% and a zinc ion content of 0.1 to 8% can be obtained.

In the present invention, it is also possible to perform ion exchange by using an aqueous solution containing each ion alone in addition to the mixed aqueous solution as described above and sequentially bringing each aqueous solution into contact with zeolite. The concentration of each ion in each aqueous solution can be determined according to the concentration of each ion in the mixed aqueous solution.

The zeolite after the ion exchange is thoroughly washed with water and then dried. Drying is preferably carried out at 105 ° C. to 115 ° C. under normal pressure or at 70 ° C. to 90 ° C. under reduced pressure (1 to 30 torr).

Ion exchange of ions or organic ions without a suitable water-soluble salt such as tin or bismuth can be carried out by using a solution of an organic solvent such as alcohol or acetone so that a sparingly soluble basic salt is not deposited.

The antibacterial activity of the antibacterial zeolite of the present invention thus obtained can be evaluated by measuring the minimum inhibitory concentration (MIC) against various general bacteria, fungi and yeasts.

The following bacteria can be used for the test. Bacillus cereus bar mycoides [Bacillus ceeus var mycoides, ATCC 11778 (malt)] Escherichia coli [Esherichia coli, IFO 3301] Pseudomonas aeruginosa, IIDP-1] Staphylococcus aureus [Staphyloc ATCC 6538P] Strepto coccus faecalis, RATCC 8043 Aspergillus niger IFO 4407 Aureobasidium pullulans IFO 6353 Ketodium glovosum ATCC 6538P (Gliocladium virens IFO 6355) Penicillium funiculosum IFO 6345 Candida albicans IFO 1594 Saccharomyces cerevisiae IFO 1950 Minimal inhibitory concentration test In the test, the minimum growth inhibitory concentration is defined as the lowest concentration at which growth is inhibited after plating culture of the inoculating bacterial solution on a plate medium to which a test sample of antibacterial zeolite is added at an arbitrary concentration.

The present invention also provides an antibacterial resin composition containing the above antibacterial zeolite and a resin. As the resin, for example, polyethylene, polypropylene, vinyl chloride, ABS resin, nylon, polyester, polyvinylidene chloride, polyamide, polystyrene, polyacetal, polyvinyl alcohol, polycarbonate, acrylic resin, fluorine resin, polyurethane elastomer, polyester elastomer, phenol resin, Urea resin, melamine resin, unsaturated polyester resin, epoxy resin, urethane resin,
Mention may be made of thermoplastic or thermosetting resins such as rayon, cupra, acetate, triacetate, vinylidene, natural and synthetic rubbers. The antibacterial resin composition of the present invention can be obtained by directly kneading the above antibacterial zeolite into the above resin or coating the surface thereof. From the viewpoint of adding antibacterial / mildew-proof / algae-proof functions to the above resin, it is appropriate to contain 0.05-80%, preferably 0.1-80% of antibacterial zeolite. The MIC of the antibacterial resin composition can be performed in the same manner as described above. Further, from the viewpoint of substantially preventing discoloration of the resin, the content of the antibacterial zeolite is preferably 0.1 to 3%.

The antibacterial zeolite of the present invention can be used in various fields.

In the water system field, it can be used as a water purifier, a cooling tower water, and an antibacterial and algae agent for various kinds of cooling water, and also a cut flower prolongation agent.

In the paint field, oil-based paints, lacquers, varnishes, alkly resin-based, aminoalkyd resin-based, vinyl resin-based, water-based,
It is possible to add antibacterial / mildew / algaeproofing function to the coating film by directly mixing with or coating on the coating film surface of various coatings such as powder type, chlorinated rubber type and phenol type. In the field of construction, it is possible to add antibacterial / mildew-proof and algae-proof functions by mixing them with joint materials, wall materials, tiles, or by coating the surfaces thereof.

In the papermaking field, it is possible to add antibacterial and antifungal functions to these papers by incorporating them into wet tissues, paper packaging materials, cardboards, liners, and freshness-keeping papers, or coating them. It can also be used as a slime control agent in the papermaking field.

The antibacterial zeolite of the present invention is not limited to the above fields,
It can be used in all fields where it is necessary to prevent the generation and growth of microorganisms such as general bacteria / fungi and algae.

Hereinafter, the present invention will be described in more detail with reference to Examples.

Example 1 (Preparation of A-type zeolite) Sodium hydroxide 49% solution 5 in aluminum hydroxide 1770 g
After adding 510 g and heating and melting, the temperature was kept below 35 ° C (hereinafter I
liquid). Colloidal silica (Nissan Chemical Snowtex 30)
Water (5160 g) was added to 4520 g and dissolved to bring the liquid temperature to 35 ° C or lower (hereinafter liquid II). The liquid I and the liquid II were mixed in a reaction kettle while adjusting the temperature of the solution to 35 ° C or lower.

The obtained mixture (raw material slurry) was stirred at 32-35 ° C for 5 hours (nucleation step). Then the obtained slurry is
The mixture was stirred at 38 ° C for 24 hours (crystal growth step). The product was filtered, washed with water, and then dried at 100 ° C. to obtain sample No. 1. The sample was subjected to chemical composition and particle size analysis.
The results are shown in Table 1. Further, the X-ray diffraction test results are shown in Table 2. Incidentally, the X-ray diffraction test data of the A-type zeolite disclosed in JP-B-32-6713 are also shown as standard data.

Further, the compositions of the raw material slurries and the reaction conditions were changed as shown in Table 1 to obtain Sample Nos. 2 to 9. The results are shown in Table 1.

From the results of Tables 1 and 2, it can be seen that the A-type zeolite is obtained.

Comparative Example Sample Nos. 10 to 12 were obtained in the same manner as in Example 1 in which the composition of the raw material slurry and the stirring temperature in the nucleation step and the crystal growth step were changed. Table 1 shows the raw material slurry composition, reaction conditions, and analysis results.

Example 2 (Preparation of antibacterial zeolite) Each sample was heated and dried at 110 ° C. for zeolite powder 1
Water was added to kg to make a 1.3 l slurry, which was then stirred and degassed, and an appropriate amount of 0.5N nitric acid solution and water were added to adjust the pH to 5 to 7, and the total volume was made to be 1.8 l slurry. did. Then for ion exchange, the total volume and 4.8l added a mixed aqueous solution 3l of M AgNO ₃ aqueous solution or M AgNO ₃ and M NH ₄ NO _3, the slurry
The temperature was maintained at 40 to 60 ° C., and stirring was performed for 10 to 24 hours, and the equilibrium state was maintained. After the completion of ion exchange, the zeolite phase was filtered and washed with room temperature water or warm water until excess silver ions in the zeolite phase disappeared. Next, the sample was heated and dried at 110 ° C. to obtain 12 kinds of antibacterial zeolite samples. Data relating to the obtained No.S-1 to No.S-12 antibacterial zeolite samples are shown in Table 3.

Example 3 (Discoloration test) A heat-dried antibacterial zeolite sample was kneaded with a resin at a kneading amount of 2% by weight and then injection-molded (residence time: 2 minutes) to obtain a sample (piece size: 7.3 cm ×). 4.4cm × 2m
m). The color of the obtained sample is measured with Minolta color difference meter CR-100 type (using D ₆₅ rays) by placing each sample on white Kent paper (L ^* a ^* b ^* 93.1, -0.7, -0.5). Then, ΔE was calculated from the result. Table 3 shows ΔE immediately after injection molding
Fig. 1 shows the change with time of L ^* sample / L ^* blank.
It is shown in FIG.

(Resin) Nylon: Mitsubishi Kasei Novamid 1010J Polypropylene (PP): Ube Industries J-109G Low Density Polyethylene (LDPE): Asahi Kasei Suntec F-
1920 Polystyrene (PS): Dainippon Ink & Paper GH9600 EFFECTS OF THE INVENTION The present invention has a particle size of 0.4 μm at the maximum measured by an electron microscope (SEM), and Sio ₂ / Al ₂ O ₃ (molar ratio)
Provides a new submicron type A zeolite having a size of 2.0 or more. Further, the antibacterial zeolite utilizing the A-type zeolite has extremely little discoloration of the resin when kneaded into the resin and discoloration of the resin with time, as compared with conventional products.

[Brief description of drawings]

FIGS. 1 to 4 show the relationship between L ^* sample / L ^* blank and the elapsed days in order to show the change with time of the color of the resin containing the antibacterial zeolite of the present invention.

Continuation of the front page (51) Int.Cl. ⁶ Identification number Reference number within the agency FI Technical indication location A61K 33/00 ADZ 9454-4C (56) Reference JP-A-57-77022 (JP, A) JP-B-58 -54088 (JP, B2)

Claims (5)

[Claims] 1. A raw material slurry containing an aluminum compound, a silicon compound and an alkali metal compound is prepared, and the raw material slurry is stirred at a temperature of 40 ° C. or lower for 3 to 48 hours to generate zeolite nuclei, and the zeolite nucleation is further performed. An electron microscope having a SiO ₂ / Al ₂ O ₃ (molar ratio) of 2.0 or more, which is produced by holding a slurry containing the above-mentioned zeolite nuclei at a temperature equal to or higher than the temperature to grow zeolite crystals. The maximum particle size measured by is 0.
Submicron A-type zeolite with a size of 4 μm or less. 2. A raw material slurry containing an aluminum compound, a silicon compound and an alkali metal compound is prepared, and the raw material slurry is stirred at a temperature of 40 ° C. or lower for 3 to 48 hours to generate zeolite nuclei, and the zeolite nucleation is further performed. An electron microscope having a SiO ₂ / Al ₂ O ₃ (molar ratio) of 2.0 or more, which is produced by holding a slurry containing the above-mentioned zeolite nuclei at a temperature equal to or higher than the temperature to grow zeolite crystals. The maximum particle size measured by is 0.
An antibacterial zeolite obtained by ion-exchanging a part or all of the ion-exchangeable metal in a submicron type A zeolite having a size of 4 μm or less with an antibacterial metal ion. 3. The antibacterial zeolite according to claim 2, wherein the antibacterial metal ion is selected from the group consisting of silver, copper and zinc. 4. A raw material slurry containing an aluminum compound, a silicon compound and an alkali metal compound is prepared, and the raw material slurry is stirred at a temperature of 40 ° C. or lower for 3 to 48 hours to generate zeolite nuclei, and the zeolite nucleation is further performed. An electron microscope having a SiO ₂ / Al ₂ O ₃ (molar ratio) of 2.0 or more, which is produced by holding a slurry containing the above-mentioned zeolite nuclei at a temperature equal to or higher than the temperature to grow zeolite crystals. The maximum particle size measured by is 0.
An antibacterial zeolite obtained by exchanging a part or all of the ion-exchangeable metals in a submicron A-type zeolite having a size of 4 μm or less with antibacterial metal ions and ammonium ions. 5. The antibacterial zeolite according to claim 4, wherein the antibacterial metal ion is selected from the group consisting of silver, copper and zinc.