JPH0541759B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to wallpaper with antibacterial properties. Traditionally, wallpaper is made of Western or Japanese paper made from pulp or even waste paper materials, and is typically made by laminating a front paper layer and a backing paper layer together with an adhesive. A problem with using wallpaper is the growth of mold.
That is, mold is likely to grow between the wallpaper and the wall, on the surface of the wallpaper, or inside the wallpaper, especially during the rainy season. The present invention provides wallpaper that suppresses the growth of mold for many years. That is, the present invention is composed of two layers, a front paper and a back paper, which are bonded to each other with an adhesive, and the adhesive and the front paper ion-exchange and retain metal ions that have a bactericidal effect. are doing. 150
Specific surface area of m ² /g or more and SiO ₂ /Al ₂ O ₃ of 14 or less
The present invention is an antibacterial wallpaper characterized by containing zeolite solid particles having a molar ratio. In the present invention, zeolite-based solid particles having a bactericidal effect are those made by ion-exchanging and retaining one or more metal ions having a bactericidal effect in the ion-exchangeable part of natural or synthetic zeolite made of aluminosilicate. It is something that exists. Ag, Cu, and Zn are suitable examples of metal ions with bactericidal effects.
can be mentioned. It is therefore possible to use the above-mentioned bactericidal metals alone or in combination for the above-mentioned purposes. Zeolite is generally an aluminosilicate with a three-dimensionally developed skeleton structure, and generally has a structure of XM ₂ /n0・Al ₂ O ₃・based on Al ₂ O ₃ .
It is expressed as ySiO ₂・ZH ₂ O. M represents an ion-exchangeable metal ion, usually a monovalent to divalent metal, and n corresponds to this valence. On the other hand, X and y are the coefficients of metal oxide and silica, respectively, and Z
represents the number of water of crystallization. Many types of zeolites are known, differing in their composition ratio, pore diameter, specific surface area, etc. However, the specific surface area of the zeolite solid particles used in the present invention is 150 m ² /g or more (based on anhydrous zeolite), and the zeolite constituent SiO ₂ /Al ₂ O ₃
The molar ratio should be 14 or less, preferably 11 or less. The solution of water-soluble salts of metals having a bactericidal action, such as silver, copper, and zinc, used in the present invention easily undergoes ion exchange with the zeolite defined in the present invention, so the solution is prepared by taking advantage of this phenomenon. It is possible to hold the above metal ions alone or in a mixed form in a zeolite stationary phase, but the zeolite particles holding metal ions must have a specific surface area of 150 m ² /g or more and a SiO ₂ /Al ₂ O ₃ molar ratio is
Two conditions must be met: 14 or less. If this is not the case, the object of achieving effective bactericidal action cannot be obtained. This is thought to be due to the fact that the absolute amount of metal ions fixed on the zeolite is insufficient in a state where the effect can be exerted.
In other words, this is thought to be due to the physicochemical properties of the zeolite, such as the amount of exchange groups, exchange rate, and accessibility. Therefore, zeolites with a high SiO ₂ /Al ₂ O ₃ molar ratio, known as molecular sieves, are completely unsuitable for the present invention. Furthermore, in zeolite with a SiO ₂ /Al ₂ O ₃ molar ratio of 14 or less, it is possible to uniformly retain metal ions that have a bactericidal effect, and for this reason, it is only by using such zeolite that a sufficient bactericidal effect can be achieved. can get. In addition, zeolite
The acid and alkali resistance of zeolites with a high silica ratio (SiO ₂ /Al ₂ O ₃ molar ratio exceeding 14) increases with increasing SiO ₂ , but on the other hand, it takes a long time to synthesize, and from an economical point of view, It is not advisable to use zeolites with such high silica ratios. mentioned above
Natural or synthetic zeolites with SiO ₂ /Al ₂ O ₃ ≦14 can be used satisfactorily in the fields in which this structure is normally considered in terms of acid resistance and alkali resistance, and are economically inexpensive. This is a good idea. From this point of view as well, the SiO ₂ /Al ₂ O ₃ molar ratio must be 14 or less. As the zeolite material having a SiO ₂ /Al ₂ O ₃ molar ratio of 14 or less used in the present invention, either natural or synthetic zeolite can be used. For example, natural zeolite is anal-
cime: _SiO2 / _Al2O3 =3.6 _{~ 5.6} ), Chabazite: _SiO2 / _Al2O3 =3.2~6.0 and 6.4~
7.6), Clino-ptilolite:
SiO ₂ /Al ₂ O ₃ = 8.5 to 10.5), Erionite (Erionite: SiO ₂ / Al ₂ O ₃ = 5.8 to 7.4), Faujasite (Faujasite: SiO ₂ / Al ₂ O ₃ = 4.2 to 4.6),
Mordenite: SiO ₂ /Al ₂ O ₃ = 8.34
~10.0), flip site (Phillipsite: SiO ₂ /
_Al2O3 = _2.6-4.4 ), etc. These typical natural zeolites are suitable for the present invention. On the other hand, typical synthetic zeolites include A-type zeolite (SiO ₂ /Al ₂ O ₃ = 1.4-2.4), X-type zeolite (SiO ₂ /Al ₂ O ₃ = 2-3), and Y-type zeolite. (SiO ₂ /Al ₂ O ₃ = 3 to 6), mordenite (SiO ₂ /Al ₂ O ₃ = 9 to 10), etc. These synthetic zeolites are suitable as the zeolite material of the present invention. Particularly preferred are synthetic A-type zeolites, X-type zeolites, Y-type zeolites and synthetic or natural mordenites. The shape of the zeolite is preferably in the form of fine powder particles, and can be, for example, several microns to several tens of microns or several hundred microns or more. In the present invention, the wallpaper itself has a two-layer structure in which a front paper layer and a backing paper layer are bonded together with an adhesive. The front paper layer is made of high-quality Japanese paper or Western paper, and the back paper layer can contain waste paper as a raw material. A synthetic resin film can also be used instead of the front paper layer or backing paper layer. The antibacterial wallpaper of the present invention is composed of zeolite solid particles and conventionally known wallpaper, and at least a portion of the zeolite solid particles retain metal ions having a bactericidal effect. The proportion of the zeolite solid particles in the whole (based on anhydrous zeolite) is 0.01 to 15% by weight. If it is less than the above lower limit, the antibacterial effect is unsatisfactory. On the other hand, even if the above upper limit is exceeded, the antibacterial effect remains almost unchanged, and the weight of the wallpaper becomes unnecessarily heavy. From this point of view, a more preferable content range is 0.05 to 10% by weight.
It is. Metal ions must be retained in the zeolite solid particles through an ion exchange reaction. If it is simply adsorbed or attached without ion exchange, the bactericidal effect and its sustainability will be insufficient. The various zeolites defined in the present invention are
For example, when converting to Ag-zeolite,
Normally, a solution of water-soluble silver salt such as silver nitrate is used in Ag-zeolite conversion, but care must be taken not to increase the concentration thereof. For example, when converting A-type _or As a result of the exchange, silver ions replace sodium ions in the solid phase, and at the same time, silver oxides and the like are precipitated in the zeolite solid phase. This has the disadvantage that the porosity of the zeolite is reduced and the specific surface area is significantly reduced.
Furthermore, even if the specific surface area does not decrease significantly, the bactericidal activity decreases due to the presence of silver oxide itself. In order to prevent such excess silver from being deposited on the zeolite phase, the concentration of the silver solution should be diluted, e.g.
It is necessary to keep it below 0.3 MAgNO ₃ . The safest concentration of AgNO ₃ is 0.1M or less. When an AgNO ₃ solution with such a concentration was used, the specific surface area of the Ag-zeolite obtained was almost the same as that of the zeolite used as the conversion material, and it was found that the bactericidal effect could be exhibited under optimal conditions. Next, when the zeolites defined in the present invention are converted to Cu-zeolite, the same phenomenon as that for Ag-zeolite described above occurs depending on the concentration of the copper salt used for ion exchange. For example A-type or
When converting -type zeolite (sodium-type) to Cu-zeolite by ion exchange reaction,
When using 1MCuSO ₄ , Cu ²⁺ replaces Na ⁺ in the solid phase, but at the same time Cu ₃ is added to the zeolite solid phase.
The porosity of zeolite decreases due to the precipitation of basic precipitates such as (SO ₄ )(OH) ₄ , which has the disadvantage that the specific surface area decreases significantly. In order to prevent such excessive copper from being deposited in the zeolite phase, it is preferable to maintain the concentration of the water-soluble copper solution used in a more dilute state, for example, 0.05M or less. When using a _CuSO4 solution with such a concentration, the specific surface area of the Cu-zeolite obtained is almost the same as that of the converted material zeolite,
It was found that this method has the advantage of being able to exhibit its bactericidal effect under optimal conditions. It was mentioned that when converting to Ag-zeolite and Cu-zeolite, solids may precipitate on the zeolite solid phase depending on the concentration of salts used for ion exchange, but when converting to Zn-zeolite, the salts used This phenomenon is not observed when the distance is around 2 to 3M. Zn usually used in the present invention
- Zeolite can be easily obtained by using salts at concentrations near the above. When carrying out the ion exchange reaction in a batch method for conversion into the above-mentioned Ag-zeolite, Cu-zeolite and Zn-zeolite, the zeolite material may be immersed in a salt solution having the above-mentioned concentration. In order to increase the metal content in the zeolite material, the number of batch treatments may be increased. On the other hand, when treating a zeolite material by a column method using a salt solution having the above concentration, the desired metal-zeolite can be easily obtained by filling an adsorption tower with the zeolite material and passing the salt solution through it. can get. The amount of metal in the above metal-zeolite (based on anhydrous zeolite) is less than 30% by weight for silver, with a preferred range of 0.1 to 5% by weight. Usually, 0.5 to 1% is sufficient for weak bacteria, and 1 to 3% for strong bacteria. On the other hand, regarding the copper and zinc used in the present invention, the action of copper is generally 1/7 of that of silver, and the action of zinc is also about 1/13, so they are required in larger amounts than silver. Further, even if metal ions other than silver, copper, and zinc, such as sodium, potassium, calcium, or other metal ions, coexist, the bactericidal effect is not hindered, so the residual or coexistence of these ions is not a problem. In the wallpaper of the present invention, the front paper and the adhesive for bonding the front paper and the back paper contain the bactericidal metal ion-containing zeolite obtained as described above. Methods for incorporating the zeolite into the adhesive include, for example, mixing it into the adhesive used for laminating the front paper layer and the backing paper layer, or spraying it on the adhesive after it has been applied to the paper layer. Examples include a method to do so. Examples of methods for incorporating the above-mentioned zeolite into the surface paper include a method in which it is uniformly mixed into paper raw materials in any of the paper manufacturing processes. Since the bactericidal metal ions are tightly bound to the zeolite, they do not fall out during the process and do not lose their bactericidal action. This method can be performed for the front paper or for both the front paper and the back paper. Alternatively, the zeolite-containing surface paper may be made by applying the zeolite-containing surface cosmetic to the surface paper before or after adhesion to the backing paper. The bonding force between the zeolite defined in the present invention and antibacterial metal ions such as silver, copper, and zinc is extremely large, unlike a method in which the zeolite is held by an adsorbent substance such as activated carbon or alumina simply by physical adsorption. Therefore, the strong bactericidal ability of the polymer containing such metallic zeolite and its long-term durability should be particularly mentioned as the characteristic advantages of the present invention. The zeolite defined as in the present invention has the advantage of high reactivity with Ag, Cu, and Zn, which have bactericidal activity. For example, A
The ion ^{- exchangeable} metal ions (Na ⁺ ) ⁱⁿ -type zeolite, It retains sterilizing metal ions in its matrix and has a high retention capacity. In addition, the zeolite limited as in the present invention is
It has the advantage of high selective adsorption for Ag ⁺ , Cu ²⁺ and Zn ²⁺ . This fact shows that even if the wallpaper containing zeolite particles of the present invention gets wet due to condensation, etc.
This means that Ag ⁺ , Cu ²⁺ , and Zn ²⁺ are stably retained in the zeolite matrix for a long period of time, and the bactericidal activity is maintained for a long period of time. In addition, the zeolite limited as in the present invention is
Ag and Cu have a large exchange capacity and sterilizing power.
It also has the advantage of increasing the amount of Zn retained.
In addition, depending on the usage environment of the antibacterial wallpaper of the present invention, Ag, Cu, and Zn may be added to the zeolite solid particles.
It has the advantage that the amount can be easily adjusted by ion exchange. Moreover, the zeolite defined in the present invention rarely deteriorates the physical properties of wallpaper. Moreover, since the wallpaper of the present invention also has the original functions of zeolite, it is possible to utilize both antibacterial properties and the original functions of zeolite.
For example, zeolite's natural moisture-absorbing and adsorbing effects help prevent wallpaper from getting wet due to dew condensation. Next, examples of the present invention will be described, but the present invention is not limited to these examples unless the gist thereof is exceeded. Example Antibacterial wallpaper A-type zeolite (composition
0.94Na ₂ O・Al ₂ O ₃・1.92SiO ₂・xH ₂ O, average particle size
1.1μ, 100℃ dry moisture content 16.0% by weight, specific surface area 664
m ² /g) and add it to 0.1M silver nitrate aqueous solution or
2.6% by weight by repeated impregnation in 0.05M copper sulfate aqueous solution
Silver (based on anhydrous zeolite) or 8.0% by weight (same)
A bactericidal metal-containing zeolite containing copper was obtained. A two-layer wallpaper with a front paper and a back paper was made, consisting of 73% by weight of wood pulp and 27% by weight of inorganic chemicals, inorganic minerals, organic adhesives and organic flame retardants. The adhesive for bonding the two layers is mixed with zeolite containing 8.0% copper in the amount shown in Table 1 below, the adhesive is used in an amount of 75 g/ ^m2 , and the zeolite content (%) in the table is , the amount for the adhesive. In addition, a surface cosmetic mainly composed of vinyl acetate containing zeolite containing 2.6% silver in the amount shown in Table 1 was applied to the surface of the wallpaper in an amount of 75 g/m ² . In Table 1, the zeolite content (%) is % by weight based on the surface cosmetic material containing 40% solid content.

[Table] Antibacterial activity test 1 Test purpose The antibacterial activity of the sample against bacteria and mold was tested. 2 Test method The antibacterial activity of the sample against Escherichia coli and Aspergillus niger was tested using the halo test and the AATCC test.
Tested according to Methcd 100-1981. (1) Presence or absence of a growth inhibition zone (halo) Bacterial strains used Escherichia coli IID-0-55 (E. coli) Aspergillus niger IFO 4414 (Koji mold) Preparation of test bacterial solution Escherichia coli was cultured overnight in bouillon medium and then incubated with sterile physiological saline. The bacteria were diluted to about 10 ⁵ /ml using a microorganism, and this was used as a bacterial solution. A. niger was cultured on a potato dextrose agar slant medium until sufficient spores were formed, and then suspended in sterilized water containing 0.005% sodium dioctyl succinate so that the number of spores was approximately 10 ⁵ /ml. Preparation of agar plates Trypto soy agar (TSA) and potato dextrose agar (PDA) approx.
After pouring each ml into a shear dish and solidifying it,
0.1 ml of the previously prepared bacterial solution was smeared on a TSA plate for Escherichia coli and on a PDA plate for Aspergillus niger. Test procedure Approximately 4 cm x 4 cm on each prepared agar plate medium
Place the sample piece cut into the size of E. coli.
After culturing at 35℃ for 24 hours, Koji niger mold was incubated at 25℃,
After culturing for 4 days, the presence or absence of a growth inhibition zone was observed. (2) Test according to AATCC Test Method 100-1981 Bacterial strains used Escherichia coli IID 0-55 (E. coli) Aspergillus niger IFO 4414 (Aspergillus niger IFO 4414 (Aspergillus niger) Preparation of test bacterial solution Escherichia coli was cultured in AATCC broth overnight; After sufficiently forming spores on a PDA slant medium, each strain was diluted with sterilized saline containing ^0.1 % Triton Test procedure: Inoculate 0.5 ml of the bacterial solution onto five specimens cut into approximately 3 cm x 3 cm sizes. For Escherichia coli, inoculate immediately after inoculation and after leaving at 35°C for 6 hours. For Aspergillus niger, immediately after inoculating and at 25°C, 24° C. The number of viable bacteria was measured after being left on the plate for an hour. The number of viable bacteria was measured as follows. In other words, add the sample to 100 ml of SCDLP broth medium.
The sample was shaken out for 1 minute, and the number of viable bacteria in the shaken out solution was measured by a pour plate culture method using SCDLP agar medium for Escherichia coli and GPLP agar medium for Aspergillus niger. 3 Test results (1) Presence or absence of growth inhibition zone (halo) The results are shown in Table 2.

[Table] (2) Test results according to AATCC Test Method 100-1981 are shown in Table-3 and Table-4. The reduction rate was calculated using the following formula. Number of viable bacteria immediately after inoculation - number of viable bacteria after 6 (24) hours / number of viable bacteria immediately after inoculation x 100 (%)

【table】

[Table] As is clear from Tables 2 to 4 above, the wallpaper of the present invention exhibits a remarkable antibacterial effect.

Claims (1)

[Claims] 1. It is composed of two layers, a front paper and a back paper, which are bonded together with an adhesive, and the adhesive and the front paper are ion-exchanged with metal ions that have a bactericidal effect. Antibacterial wallpaper, characterized in that it contains zeolitic solid particles having a specific surface area of 150 m ² /g or more and a SiO ₂ /Al ₂ O ₃ molar ratio of 14 or less. 2 The zeolite solid particles are A-type zeolite,
The wallpaper according to claim 1, which is composed of X-type zeolite, Y-type zeolite or mordenite. 3. The wallpaper according to claim 1, wherein the metal ion having a bactericidal effect is one or more metal ions selected from the group consisting of silver, copper, and zinc. 4 The content of zeolite solid particles (based on anhydrous zeolite) is 0.01 to 15% by weight based on the total weight of the wallpaper.
The wallpaper according to claim 1, which is