JPH06271775A - Improved highly water-absorbing resin composition - Google Patents

Abstract

PURPOSE:To prevent a highly water-absorbing resin from suffering a trouble caused by a microorganism particularly in long-term continuous use because this resin is usable in various applications. CONSTITUTION:This resin composition contains an inorganic antibacterial agent comprising a porous gel, e.g. zeolite or silica gel, as a carrier and an antibacterial metal ingredient comprising silver supported thereon. This composition can be used alone or in combination with other ingredient(s). Even when used over long, the composition can be prevented from suffering a trouble caused by a bacterium or fungus.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION Highly water-absorbent resins and compositions containing the same have been widely used in various fields. The present invention relates to a field that requires continuous use over a relatively long period of time among the various fields.

[0002]

2. Description of the Related Art There are many products using a composition containing a super absorbent polymer as one component. The super absorbent polymer is made by insolubilizing a hydrophilic polymer by various means such as cross-linking, but has various shapes and forms depending on the manufacturing method and application. The super absorbent polymer may be used alone, but is often used in combination with other multi-components. These compositions have a wide range of applied fields, such as cosmetics / toiletry fields, sanitary materials fields, agricultural / horticultural fields, food packaging fields, medical fields, and civil engineering / building fields. Among them, sealing materials, horticultural soil, water retaining materials for plant cultivation, packaging materials for maintaining food freshness, soundproofing materials, vibration absorbing materials or interior materials for constructs, etc. Although it is often thought that it is difficult to engraft, microorganisms, on the other hand, tend to proliferate depending on environmental conditions, and often face troubles due to bacteria and mold during use.

[0003]

There has been a strong demand for a technique for avoiding the above-mentioned troubles caused by microorganisms in the continuous use of superabsorbent resins.

[0004]

[Means for Solving the Problems] There are many useful superabsorbent resin compositions and products. The super absorbent polymer is a polymer obtained by cross-linking a hydrophilic polymer by various means to make it insoluble, and has various shapes and forms depending on the manufacturing method and application. For example, applied fields are wide-ranging, such as cosmetics / toiletry fields, sanitary materials fields, agricultural / horticultural fields, food packaging fields, medical fields, and civil engineering / building fields. As already mentioned,
Among them, sealing materials, water-retaining materials for plant cultivation, packaging materials for maintaining food freshness, soundproofing materials, vibration absorbing materials or interior materials for constructs, etc., often encounter troubles due to various microorganisms in use in long-term continuous use. It was. In a word, the means for solving the above-mentioned problems is effective in utilizing an antibacterial agent suitable for the purpose. The drawback of organic antibacterial agents as antibacterial agents is that the sharpness of the antibacterial spectrum, which is the greatest feature of organic antibacterial agents, does not work on the contrary in these applications in which it is difficult to identify bacterial species or mold species. unavoidable. Further, it is difficult to control the sustained release of the antibacterial agent from the hydrophilic gel, and in general, the chemical stability under the use environment is not sufficient, and it is not easy to maintain the effect. Inorganic antibacterial agents that play the role of antibacterial metals such as silver and copper have a broad antibacterial spectrum that organic systems do not have, and also have excellent safety such as heat resistance and chemical resistance, and excellent sustainability of practical effects. As expected, the inventors of the present invention have found that the incorporation of this inorganic antibacterial agent is suitable for the purpose of long-term continuous use. The inorganic antibacterial agent is one in which a so-called antibacterial metal such as silver is supported by using a porous substance such as zeolite, silica gel, or other porous gel as a carrier, and its effectiveness has recently been recognized. Currently, typical products are those with zeolite as a carrier, such as "Zeomic" (manufactured by Sinanen Co., Ltd.) and "Novalon" (manufactured by Toagosei Chemical Industry Co., Ltd.). Supplied in physical condition.
There are various methods of mixing the antibacterial agent with the superabsorbent resin, but as already mentioned, in order to fully demonstrate the capacity of the antibacterial agent, in many cases, before molding according to the application of the superabsorbent resin. It is a preferred means to mix the inorganic antibacterial agent powder as it is in the raw material stage, that is, if the water-absorbent resin is in the form of powder, and if it is in the form of lump, it is pulverized. Of course, it is also possible to disperse the superabsorbent resin molded article only in the surface layer of the superabsorbent resin structure when forming a laminated form or a surface coating layer, and to mix it with the mixture when mixed with soil. Needless to say, it is necessary to select depending on the target. The amount of the inorganic antibacterial agent exhibiting effective antibacterial activity is determined not only by the water-absorbing ability of the superabsorbent resin, but also by the use and the usage state, in other words, the interaction between the superabsorbent resin composition and the environment surrounding it. It is something. For example, in a situation where a medium containing microorganisms does not flow, for example, in a product containing a superabsorbent resin for which antibacterial property is desired to be provided, for example, in a sealed environment, the antibacterial agent may have a low concentration.
It is effective at about 1 to 5% by weight. However, as it is mixed with other compositions and as the fluidity of the environmental medium increases, high concentration mixing is required. For example, there is a case where an amount of the inorganic antibacterial agent to be mixed is required to be about 15% by weight for the purpose of being easily exposed to rainwater.

The effectiveness of these systems was shown mainly by the shake-flask method according to “Testing method for evaluating processing effect of sanitary processed products” (Textile Product Processing Council). A phosphate buffer solution and a sample are put into an Erlenmeyer flask, sterilized by high-pressure steam, and cooled to 37 ° C. The bacterial solution kept at 37 ° C. is added to this, and shaken for a predetermined time under the condition of 100 times / minute. The viable cell count before and after shaking was measured by the pouring method.

[0006]

EXAMPLES The technical points for solving this problem according to the present invention are as described above, but the present invention will be specifically described below, but the present invention is not limited to these examples.

[Example 1] "Aqualic" as a super absorbent resin
An inorganic antibacterial agent "Novalon" (manufactured by Toagosei Kagaku Kogyo Co., Ltd.) was added to (Nippon Shokubai Chemical Co., Ltd.) in an amount of 1.0% by weight and sufficiently mixed with a kneader to form a sheet. The thickness of the sheet is about 0.
It was 5 mm. The antibacterial activity of the sheet has a surface area of 10 cm
^The sheet adjusted to ² was measured by the shake flask method. According to the method already described, the Pseudomonas aeruginosa dispersion liquid containing 10 ⁸ viable cells was poured into the flask. The viable cell count after 3 hours of shaking had decreased to 10 ² . The same method was used to measure Escherichia coli and Staphylococcus aureus, but the viable cell count was at the same level. These results can be regarded as showing a sufficient antibacterial effect.

Comparative Example 1 The difference in the antibacterial effect depending on the presence or absence of the addition of the inorganic antibacterial agent will be examined. A sheet was prepared under the same conditions as in Example 1 except that the inorganic antibacterial agent was added, and the antibacterial activity was measured. The viable cell count after 3 hours of shaking was 1 for all the cells.
It was more than ⁰⁹ . In comparison with the results of Example 1, the action and effect of the inorganic antibacterial agent is clear.

[Embodiment 2] An example applied as a dew condensation preventing material for a particularly high humidity storage box is shown. For this purpose, it is also preferable to apply a superabsorbent resin containing an inorganic antibacterial agent to the inner surface of the storage box, but here, in consideration of easiness of evaluation, a laminate is used to show its usefulness. The dew condensation prevention material consists of two layers. The highly water-absorbent resin layer according to the present invention is a sheet formed by mixing 2% by weight of the inorganic antibacterial agent "Novalon" and molding in the same manner as in Example 1, and polyethylene having 1 mm diameter pores formed on the entire surface thereof. The film layers were stacked to form a laminated structure. On the other hand, a laminated material using a highly water-absorbing resin containing no inorganic antibacterial agent was used as a comparative control preventive material. As one of the evaluations of the antibacterial activity, the laminated sample was subjected to the shake flask method in the same manner as in Example 1. The viable cell count of the antibacterial agent-containing laminated sheet after shaking for 3 hours was 10 ¹ or less for any of Pseudomonas aeruginosa, Escherichia coli, and Staphylococcus aureus. 1 for the control material
It was a viable cell count of ⁰⁹ . These anti-condensation materials were attached to the inner surface of the storage box and left at a relative humidity of 80% for 15 days. In the case of using a super absorbent polymer containing no inorganic antibacterial agent, many black spots due to mold adhered to the surface of the dew condensation preventing material, but an example using a superabsorbent resin containing an inorganic antibacterial agent was used. Then, such a sunspot was not recognized at all.

Example 3 Here, an example of application to the horticultural soil will be shown. Super absorbent resin "Diawet" (manufactured by Mitsubishi Petrochemical Co., Ltd.) and 25% by weight of inorganic antibacterial agent "Zeomic"
Mix well (Sinanen Co., Ltd.) with a kneader. 8 parts by weight per 20 parts of the super absorbent polymer composition containing this inorganic antibacterial agent
0 parts of soil is mixed to prepare improved soil. Saintpaulia was potted using only the mixed soil of the improved soil, the soil containing the superabsorbent resin containing no inorganic antibacterial agent, and the soil, and the growth conditions of the three were observed. As a result of observing after 2-3 months, generation of mold was observed on the surfaces of the two soils except the improved soil. In addition, Saintpaulia grown using the improved soil was rarely rooted.

[0007]

EFFECTS OF THE INVENTION The highly water-absorbent resin composition containing the inorganic antibacterial agent according to the present invention can avoid troubles caused by bacteria and mold during use, and thus can be continuously used for a long period of time. It was

Claims (1)

[Claims] 1. A highly water-absorbent resin in which an antibacterial metal in an inorganic antibacterial agent made of an antibacterial metal is at least a silver component, and a carrier contains an inorganic antibacterial agent made of zeolite, silica gel or other porous gel. Composition.