JPH0446197B2 - - Google Patents

Description

[Detailed description of the invention]

(Industrial Application Field) The present invention relates to granules that stably and continuously release the active ingredients contained in water little by little. The present invention relates to a sustained release granule that enables the replenishment of such substances. (Prior art) Activated carbon is generally used in water purifiers for the purpose of removing dust, deodorizing, decolorizing, etc. If vitamins, minerals, etc. can be added to drinking water at the same time as purification, it would be possible to create healthy drinking water. It's good to be able to do it. In this case, it may be possible to mix vitamins, minerals, etc. with the activated carbon in the water purifier, but a large amount of them would be eluted at once, and it would be difficult to make them elute continuously and stably for a long period of time. (Problems to be Solved by the Invention) Therefore, attempts have been made to mix vitamins and minerals with appropriate inorganic salts and mold the mixture into granules using polyvinyl alcohol as a binder. However, even in this granular material, it was difficult to control the elution rate. For example, granules absorb into water, crack and often disintegrate, but on the other hand, if the amount of binder is increased to increase the strength in water to prevent disintegration, the elution rate of the active substance will be reduced. (Means for Solving the Problems) The present inventors focused on controlling the release of small amounts of ingredients mixed in granules, and as a result of intensive research, we unexpectedly discovered that vitamins, minerals, etc. can be mixed with activated carbon powder. The mixture is mixed and granulated using vinyl acetate resin liquid as a binder. By coating the surface with paraffin, it is absorbed into the inside of the granules, allowing accurate, stable and continuous release over a wide range. The present inventors have discovered that it is possible to obtain granules that can be controlled over a long period of time, and have completed the present invention. That is, the present invention provides activated carbon powder and various vitamins, minerals, etc. (hereinafter simply referred to as minerals, etc.).
The present invention provides sustained-release granules in water, which are obtained by granulating a powder mixture using a resin binder and impregnating it with paraffin. In the present invention, there is no particular restriction on the type of activated carbon powder. The finer the powder, the better, but usually 4
The size of ~250 mesh (4.76 ~ 0.063 mm) is used. Further, activated carbon may be mixed with calcium hydrogen phosphate, calcium carbonate, alumina, etc. in an amount up to 50% by weight. In addition to normal minerals, minerals etc.
The term includes various other water-soluble compounds, such as organic germanium, calcium, sodium compounds, vitamin C, vitamin D, and vitamin E. The ratio of minerals, etc. to activated carbon powder is at most 1:1. If the amount of minerals, etc. exceeds 50% by weight of the total amount of activated carbon and minerals, etc., it becomes difficult or impossible to control the amount of elution in water. Moreover, if it is less than 1% by weight, a sufficient amount of elution cannot be obtained for a long period of time. Examples of the resin binder include polyvinyl formal, polymethyl methacrylate, and polyvinyl chloride, but vinyl acetate resin or vinyl acetate emulsion copolymerized with ethylene, styrene, acrylate, methacrylate, etc. is preferably used. This is used by dispersing it in a solvent. Ethanol is preferably used as the solvent. The amount of binder is 100 parts by weight of activated carbon.
Usually 5 to 50 parts by weight, preferably 10 to 30 parts by weight are used. If it is less than 5 parts by weight, the granulation property will be extremely reduced, and the mechanical strength of the resulting granulated product will be insufficient.
Granules disintegrate in water. The mechanical strength increases as the amount of binder increases, but if it exceeds 50 parts by weight, the porosity of the activated carbon decreases, resulting in a lack of surface area for absorbing paraffin. Conventional methods can be used for granulation, such as an extrusion method, a rolling method, and a fluidization method. Preferably, the particle size is in the range of 0.3 mm to 10 mm. Impregnation of paraffin into granules can be carried out by heating paraffin and coating the surface thereof. The amount of paraffin applied is usually 10 to 40 parts by weight, preferably 20 to 30 parts by weight, per 100 parts by weight of the granules. If the paraffin is less than 15 parts by weight, the elution of the effective substance cannot be controlled, and it will be completely eluted within several weeks, resulting in a significantly high initial elution concentration. If the amount exceeds 40 parts by weight, elution may be extremely small or no elution may occur. In the present invention, the paraffin is present on the surface immediately after coating, but after a certain period of time, at least a portion of the paraffin needs to be absorbed into the inside of the granules because the activated carbon in the granules is porous. As the paraffin, those used for coating food wrapping paper are preferred. The present invention maintains the mechanical strength of activated carbon granules and retains the porous portion by delicately balancing the ratio of activated carbon powder, resin binder, and paraffin, and impregnates the surface of the porous portion with paraffin. It is characterized by controlling the proportion of the porous portion and controlling the amount of minerals etc. eluted. The sustained release granules in water of the present invention can be prepared by using, for example, 1 to 30 parts by weight of the granules per 100 parts by weight of water, and the amount of water used per day.
Controlled in the range of 0.1 to 100ppm under the condition of 3.0,
Minerals, etc. are released stably and continuously for more than one month. (Effects of the Invention) The granules of the present invention contain minerals, etc. and have excellent mechanical strength, and gradually release them into water, stably replenishing minerals, etc. into drinking water over a long period of time. It is suitable as a granule. Moreover, the granules of the present invention using activated carbon as a base material are not only harmless but also have water purification functions such as deodorization and decolorization. (Examples) Next, the present invention will be described in more detail based on Examples. In the examples, unless otherwise specified, %
indicates weight %. Example 1 950 g of activated carbon and 50 g of germanium raw material were mixed. (As a germanium raw material, I used the one from ) Next, 100 ml of vinyl acetate resin solution (solid content: 18.5% by weight) was added to this mixture, and this was kneaded and granulated to prepare granules with a particle size of about 2 mm. Add paraffin to this granule for 20 minutes as follows:
%, 30%, 40% and 50% and sample No. 2, 3,
4 and 5 were produced. Paraffin powder and granules were placed in a fluidized fluid dryer and stirred at about 70°C in rising hot air to coat and impregnate the molten paraffin onto the granules. In addition, samples of granular materials without paraffin applied
It was ranked No.1. Take 10g of each of these granule samples No. 1 to 5, put them into 300ml Erlenmeyer flasks, and add 250g of water.
ml was added and left in a 25°C heat insulating tank. After 1, 2, 6, 24, and 48 hours had elapsed, 1 ml of water was sampled and its concentration was measured. This result is the first
Shown in the figure. The results shown in the figure show that the elution amount changes greatly depending on the amount of paraffin applied, and the elution rate can be set arbitrarily. Example 2 100 g of germanium raw material for 900 g of activated carbon powder
Granules were prepared in the same manner as in Example 1, except that g was used, and granules with paraffin coating amounts of 30%, 35% and 40% were produced in the same manner as in Example 1. Column size: 80 mm diameter, 110 mm length
Filled into a mm cylinder, 130g of granular activated carbon, 30g of this granule
g, filtered water at 3/min, and 500 ml of water was sampled every 4 hours to measure the amount of elution. The results are shown in Table 1. The pH of the water was approximately 7.2, which hardly changed between the start and end of the test.

【table】

[Table] Example 3 10g of germanium raw material for 990g of activated carbon powder
A granule was prepared by applying 30% paraffin in the same manner as Sample No. 1 of Example 2, except that granules were used, and the granules were packed into a column in the same manner as in Example 2. was measured. The results are shown in Table 2. From the results in the same table, the Ge base material is 1%.
It can be seen that even though it is 1/10 compared to sample No. 1 of Example 2, the elution amount is relatively large and stable.

【table】

【table】

【table】 [Brief explanation of the drawing]

FIG. 1 is a graph showing the relationship between the elution amount of germanium in water from the granules of Example 1 and time.

Claims (1)

[Claims] 1. A sustained-release granule in water, which is made by granulating a mixture of activated carbon powder and powders of various vitamins, minerals, etc. using a resin binder and impregnating it with paraffin.