JPH0811787B2 - Paint - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a paint used for deodorization, which is formed into a coating film for heating, hot water supply, drying, cooking, refrigerating, air conditioning equipment, etc., and is used for indoor, toilet, refrigerator, cooking. It has a function of removing odorous components existing in the container and the like.

[0002]

2. Description of the Related Art Conventionally, a method of arranging an adsorbent such as activated carbon in a room to adsorb gaseous malodorous substances and deodorize them has been mainly used. Further, recently, a method has been taken in which a device having an ozone generating function is arranged in a room and odorous components are oxidatively decomposed by ozone gas.

These malodorous substances are mainly ammonia,
Fatty acids, unsaturated hydrocarbons, sulfur-containing organic compounds such as mercaptans, nitrogen-containing organic compounds and the like are generated by physiological actions such as sweat of living humans and decomposition of foods.

[0004]

In the conventional adsorption using activated carbon, the adsorption capacity varies depending on the odor component species, and the adsorption capacity is limited, and the moisture in the atmosphere hinders the adsorption of malodorous gas. In order to do so, there is a problem that it is necessary to regularly replace the activated carbon. In addition, the odor decomposition method using ozone requires that a special device be provided to control the optimum ozone generation concentration for decomposition and deodorization, that there are odor component species that are difficult to decompose by ozone, and that the ozone generator The problem is that it has a lifetime.

The present invention has been made to solve the above-mentioned problems of the prior art, and provides a function of removing odors and harmful gases in a room with a long life by a coating film formed by a simple coating method. Is.

[0006]

DISCLOSURE OF THE INVENTION The present invention is a coating material comprising activated alumina, zeolite and / or magnesium silicate, a platinum group metal salt, an inorganic binder and a dispersion medium. In addition, a platinum group catalyst is supported on activated alumina instead of the platinum group metal salt.

[0007]

The coating film formed using the coating material of the present invention has the following coating film functions. The odorous components in the room are usually adsorbed and deodorized with zeolite or magnesium silicate in the coating film and activated alumina. Next, zeolite or magnesium silicate and activated alumina are heated in the coating film of the present invention by a heating means such as a heating element or warm air before adsorbing odorous components up to the adsorption capacity limit thereof. The catalytic substance is activated, and the zeolite or magnesium silicate in the coating film, the odor component adsorbed on the activated alumina and the odor component in the vicinity of the coating film of the activated catalyst substance coexisting with the zeolite or magnesium silicate and the activated alumina. It is oxidatively decomposed into a odorless component by the catalytic action. Zeolite or magnesium silicate heated by the heating means and activated alumina remove the adsorbed odorous components, so the adsorption ability is restored again, and after the heating by the heating means is stopped, the odorous components are adsorbed again. You can Thus, zeolite or magnesium silicate when not heated, adsorption of odorous components by alumina, and zeolite or magnesium silicate when heated,
Heat regeneration of activated alumina and catalytic decomposition of odorous components,
By repeating alternately, the malodor can be continuously removed over a long period of time.

Conventional activated carbon and transition metal-ascorbic acid complex salts, which are generally used as adsorbents, have variations in their adsorption performance depending on odorant species, whereas the adsorbents such as the zeolite of the present invention have variations in adsorption performance. It is possible to adsorb and deodorize various odor components indoors.

[0009]

EXAMPLES Magnesium silicate, which is a constituent element of the present invention, is magnesium orthosilicate, magnesium metasilicate,
It is a composition in which magnesium oxide such as talc, magnesium tetrasilicate, and magnesium trisilicate, silicon dioxide, and water are bonded in various proportions.

Zeolites are A type, X type, Y type, 1
Various zeolites such as 0-membered ring type can be used.
Among them, copper ion-exchanged zeolite is particularly preferable because it has the best odor adsorption capacity. It is desirable that the content of zeolite is 10 to 70 wt% of the solid content in the paint.

When the content of zeolite is less than 10 wt%, it is difficult to obtain sufficient adsorbability of the odorous substance in the coating film formed by the coating material of the present invention, and when it exceeds 70 wt%, the catalytic properties of the coating film are high. descend.

As the inorganic binder, various ones such as aluminum hydroxide, glass powder, water glass, clay and colloidal silica can be used. Among them, colloidal silica is the most excellent and desirable in the comprehensive evaluation of odor adsorption capacity and coating film hardness. The content of the inorganic binder is preferably 10 to 40 wt% of the solid content in the paint. If the content of the inorganic binder exceeds 40% by weight, the coating film is likely to be cracked and the adhesiveness tends to be deteriorated. On the other hand, if it is less than 10 wt%, sufficient adhesion characteristics of the inorganic binder cannot be obtained.

As the dispersion medium, a substance that evaporates in the process of forming a coating film by drying or baking after coating the coating material, for example, organic solvent such as water or alcohol can be used.

Further, an additive for stabilizing the dispersion of the solid content in the paint may be added. Various materials such as metals, ceramics, and glass can be used as the base material to which the coating material of the present invention is applied. It can be used in various shapes such as a plate shape, a honeycomb shape, a porous body, a rod shape, and a tubular shape. Of these, silica, alumina, mullite, cordierite, silica glass, and lithium silicate glass are desirable because of their good adhesion to the substrate of the coating film.

Further, the objects to which the coating material of the present invention is applied include interior walls of refrigerators, cookers and the like, air passages of air conditioners and heaters, surfaces of heating elements or surfaces near heating elements, and indoor walls. .

The platinum group metal salt is thermally decomposed by heating to become a noble metal, and the odorous substance is chemically decomposed by its catalytic oxidation action to become a deodorizing catalyst substance. Therefore, by including the platinum group metal salt in the paint, it is possible to add an odor substance decomposition function to the formed coating film. Examples of the platinum group metal include platinum, palladium, rhodium, etc., and a noble metal salt such as a nitrate or an ammine complex salt which decomposes into a noble metal by heating is used.

Further, the activated alumina contributes to highly disperse the noble metal and has a function of making the catalytic oxidation action sufficient. The coating composition of the present invention may be composed of activated alumina, zeolite, platinum group metal salt, inorganic binder, and dispersion medium, but more preferably, activated alumina carrying platinum group catalyst in advance and zeolite. It is preferable to be composed of an inorganic binder and a dispersion medium. This is because the latter coating material gives a coating film having excellent oxidative decomposition performance of odorous substances by the platinum group catalyst.

Activated alumina includes β-, γ-, δ-, θ
It is a metastable alumina having a high specific surface area such as −, η−, ρ−, χ− alumina. Further, in the coating material of the present invention, aluminum hydroxide which is thermally decomposed into an activated alumina by heating may be used instead of the activated alumina.

It is desirable that the coating material of the present invention contains a metal salt of cerium, such as nitrate, acetate, hydroxide, etc., which is thermally decomposed to cerium oxide by heating, or contains cerium oxide. By including cerium oxide in the coating film formed from the coating material of the present invention, the oxidative decomposition activity of the catalyst substance for hydrocarbon compounds can be improved.

The content of the cerium compound in terms of cerium oxide is preferably 2 to 15 wt% of the solid content in the coating material. The content of cerium oxide is 15wt%
When it exceeds the above range, the oxidative decomposition property of the catalyst substance begins to deteriorate, and when it is less than 2 wt%, a sufficient addition effect of cerium oxide cannot be obtained.

By including barium oxide in the paint, the oxidative decomposition characteristics of the catalyst can be improved. The content of barium oxide is preferably 0.5 to 5 wt% of the solid content in the paint. When the content of barium oxide exceeds 5 wt%, the adhesion property of the catalyst coating layer deteriorates, and when it is less than 0.5 wt%, sufficient addition effect of barium oxide cannot be obtained.

The same effect can be obtained by using barium carbonate instead of barium oxide. The desirable addition amount of barium carbonate is 0.5 to 50 in terms of barium oxide amount.
It is 5 wt%.

By including titanium oxide in the paint, the catalytic oxidation activity for nitrogen compounds such as ammonia can be improved. Titanium oxide content is 3% of solid content in paint
It is desirable that the content be ˜15 wt%. When the content of titanium oxide exceeds 15 wt%, the adhesion property between the coating film formed by using the coating material and the base material deteriorates, and when it is less than 3 wt%, the sufficient effect of adding titanium oxide cannot be obtained.

When forming a coating film, it is desirable to roughen the surface of the base material and then apply the coating film, or to sufficiently degrease the surface of the base material and then apply the coating film. By this manufacturing method, the adhesion between the coating film and the substrate can be improved.

Various methods can be used for forming the coating film. For example, there are spray coating, dip coating, electrostatic coating, roll coating method, screen printing method and the like.

The central particle diameter of the particles in the paint is 1 μm or more,
It is preferably 9 μm or less. When it exceeds 9 μm, the coating becomes soft, and when it becomes finer than 1 μm,
The coating film tends to crack.

Specific examples of the present invention will be described below. (Example 1) 300 g of γ-alumina, 500 g of copper ion exchange type zeolite, 1000 g of an aqueous colloidal silica solution containing 20 wt% of silica as an inorganic binder, 500 g of water, 6 g of chloroplatinic acid as Pt and 3 g of palladium chloride as Pd, Coating A was prepared by thoroughly mixing with a ball mill. This paint A is 100m long
m, width 100 mm, thickness 1 mm, applied to the surface of a quartz glass plate by a spray method, dried at 100 ° C. for 2 hours, and subsequently baked at 500 ° C. for 1 hour to thermally decompose the platinum group metal salt. A coating film A containing a platinum group catalyst was formed. The amount of coating film was 1.0 g.

A paint B having the same composition as the paint A was prepared by using talc as the same amount of magnesium silicate instead of the copper ion exchange type zeolite. Using this paint B,
A coating film B was formed on the surface of the quartz glass plate in the same manner as the coating film A.

Further, for comparison, the same composition as Paint A was used, but the same amount of activated carbon powder was used instead of the copper ion exchange type zeolite, and comparison paint 1 was used and the same amount of iron-ascorbic acid powder was used for comparison. Paint 2 was prepared. Using these comparative paints, comparative paints 1 and 2 were formed on the surface of the quartz glass plate in the same manner as the paint A.

Next, the odor substance adsorption capacity of each coating film was tested using methyl mercaptan, which is a typical odor substance.
The test method was as follows. The above various paints were placed in a closed box having a volume of 0.5 m ³ whose inner wall surface was covered with a fluorine resin, and air-diluted methyl mercaptan having a concentration of 10 ppm was adsorbed in the box to form a coating film. The amount of residual methyl mercaptan was measured 30 minutes after the quartz glass plate was put, and the result was taken as the methyl mercaptan adsorption capacity. The air in the box was stirred by the fan during the experiment. The results are shown in (Table 1).

As is clear from Table 1, as compared with Comparative Paints 1 and 2 which were formed by using the conventional adsorbents such as activated carbon and iron-ascorbic acid, the paint A containing the zeolite of the present invention and the magnesium silicate were compared. The coating film A and the coating film B using the coating material B containing were excellent in the methyl mercaptan adsorption capacity. In addition, the adsorption ability of methyl mercaptan of the coating film formed by the coating material using magnesium silicate other than talc, magnesium orthosilicate, magnesium metasilicate, magnesium tetrasilicate, magnesium trisilicate is 40, 40, respectively.
Good values of 41, 40% were obtained.

In this embodiment, zeolite and magnesium silicate are individually added to the paint, but they may be mixed and used.

[0033]

[Table 1]

(Example 2) In the coating material A prepared in Example 1, the content of copper ion exchange type zeolite (hereinafter referred to as copper zeolite) was 5 w based on all solid components in the coating material.
Various contents between t% and 80% by weight were prepared, and the copper zeolite increased amount was used to prepare a paint in which the amount of activated alumina was reduced. This paint is 100 mm long and 100 m wide as in Example 1.
m, the thickness of 1 mm is applied to the surface of a quartz glass plate by a spray method, dried at 100 ° C. for 2 hours, and then baked at 500 ° C. for 1 hour to thermally decompose the platinum group metal salt to obtain a platinum group metal. A coating film containing as a catalyst was formed. The amount of coating film was constant at 1.0 g.

With respect to these paints, the methyl mercaptan adsorption capacity and the ammonia-catalyzed oxidative deodorization performance shown in Example 1 were examined. The catalytic oxidative deodorization performance test was conducted by putting a quartz glass plate with a coating film in a closed box with a volume of 0.5 m ³ whose inner wall surface was covered with fluorine resin, and energizing the electrical resistance of the quartz glass plate with 100 V voltage. By doing so, the temperature of the coating film is set to 400. Next, ammonia was added in an amount such that the ammonia concentration in the box was 10 ppm, and oxidative decomposition was performed by the white metal catalyst in the activated coating film, and the energization time required until 80% of the ammonia in the box was oxidatively decomposed was measured. . The results are shown in (Table 2).

As is clear from (Table 2), when the content of copper zeolite is less than 10 wt%, the methyl mercaptan adsorption property deteriorates, and when it exceeds 70 wt%, 80% of the ammonia in the box is oxidized and decomposed. The required energization time becomes longer, and the catalytic oxidative deodorization performance deteriorates. Therefore, the content of copper zeolite is 10 wt% or more 70
When it is less than wt%, the best catalytic oxidative deodorization performance and odor substance adsorption ability are obtained, which is desirable.

[0037]

[Table 2]

Example 3 A coating material was prepared by replacing the copper zeolite in the coating material prepared in Example 1 with another ion-exchanged zeolite. With respect to the coating film formed on the quartz glass plate by using the same coating film forming method as in the coating film A of Example 1 using these coating materials, the odorous substance adsorption ability using the methyl mercaptan shown in Example 1 The test was conducted. The results are shown in (Table 3).

As is clear from (Table 3), copper ion-exchanged zeolite is the most preferable in terms of its ability to adsorb odorous substances, which is desirable.

[0040]

[Table 3]

(Example 4) In the paint A prepared in Example 1, the colloidal dull silica aqueous solution in the paint was changed to various inorganic binders so that the amount of the inorganic binder contained in the final solid content was the same. Prepare the replaced paint,
Similarly, a coating film was formed on a quartz glass plate. In order to examine the film hardness of these coating films, a JISG-3320 pencil hardness test was conducted. Further, each coating film was subjected to a methyl mercaptan adsorption test in the same manner as in Example 1. The results are shown in (Table 4).

As shown in (Table 4), when alumina sol or bentonite is used, the coating film hardness is lowered, and when Li silicate or water glass is used, the coating film hardness is improved, but the coating film does not become porous and odor is absorbed. The characteristics deteriorate. Therefore, it is most desirable to use colloidal silica as the inorganic binder.

[0043]

[Table 4]

(Example 5) In the coating material A prepared in Example 1, the content of colloidal silica as an inorganic binder was 0 wt% to 6 with respect to all solid components in the coating material A.
A coating material of the present invention was prepared in which the content was varied between 0 wt% and the increased amount of colloidal silica decreased the amount of copper zeolite. A thermal shock test was conducted on the coating film formed on the quartz glass plate using these coating materials by the same coating film forming method as the coating film A of Example 1 to examine the adhesion. In the thermal shock test, the quartz glass plate on which the coating film was formed was placed in an electric furnace whose temperature was set at every 25 ° C., held at that temperature for 10 minutes, and then dropped in room temperature water to check for peeling of the coating film. The maximum temperature at which peeling did not occur was taken as the thermal shock resistance temperature. The results are shown in (Table 5).

As is clear from (Table 5), when the content of the colloidal silica as the inorganic binder exceeds 40 wt%, the coating film is likely to be cracked and the adhesiveness is deteriorated. Sufficient adhesion characteristics cannot be obtained.

Therefore, the content of colloidal silica is preferably 10 to 40 wt% of the solid content in the coating material.

[0047]

[Table 5]

(Example 6) 200 g of γ-alumina, water
500 g, 6 g of chloroplatinic acid as Pt and 3 g of palladium chloride as Pd were thoroughly mixed using a ball mill and dried at 100 ° C. for 2 hours, then at 500 ° C. for 1 hour.
The platinum group metal salt was pyrolyzed by firing for a period of time to prepare γ-alumina carrying a platinum group catalyst. Next, 209 g of this γ-alumina and 500 g of copper ion exchange type zeolite,
Coating material C was prepared by thoroughly mixing 1500 g of an aqueous colloidal silica solution containing 20 wt% of silica as an inorganic binder and 500 g of water with a ball mill. This coating material C is applied to a surface of a quartz glass plate having a length of 100 mm, a width of 100 mm and a thickness of 1 mm by a spray method, and then 100 ° C.
At 500 ° C. for 1 hour to thermally decompose the platinum group metal salt to form a coating film C containing a platinum group catalyst. The amount of coating film was 1.0 g.

With respect to this coating film C and the coating film A prepared in Example 1, the same ammonia-catalyzed oxidative deodorization performance as in Example 2 was examined. The results are shown in (Table 6).

As is clear from (Table 6), the activated alumina on which the platinum group catalyst was previously supported was used rather than the coating film A formed by using the coating material A containing the activated alumina and the platinum group metal salt. The coating film C formed of the coating material C is preferable because a coating film having excellent oxidative decomposition performance of odorous substances by the platinum group catalyst can be obtained.

[0051]

[Table 6]

(Example 7) At the time of preparation of the coating material A of Example 1, the milling time in the ball mill was changed to prepare various coating materials of the present invention having a central particle diameter of 0.8 µm to 15 µm.

Using these slurries, 1.0 g of a coating film was prepared on the surface of a quartz glass plate that had been degreased and washed in the same manner as in Example 1.

Next, the film hardness of the coating film formed was measured according to JISG-
A 3320 pencil hardness test was performed. The results (Table 7)
It was shown to.

[0055]

[Table 7]

As is clear from (Table 7), if the thickness exceeds 9 μm, the coating becomes soft, and if it is smaller than 1 μm, the coating tends to crack.

Therefore, the median particle diameter of the particles in the coating material of the present invention is preferably 1 μm or more and 9 μm or less.

Example 8 Cerium nitrate hexahydrate in various amounts was added to the coating material A of Example 1, and the same amount of coating material A as that of coating material A was applied to the surface of the quartz glass plate in the same manner as in Example 1. A coating film was formed. The amount of cerium nitrate in the paint was converted into the amount of cerium oxide produced by its thermal decomposition, and a coating film was formed using paints with different amounts of cerium nitrate added as shown in (Table 8). The increase in cerium nitrate in the paint was prepared by reducing the amount of alumina.

For these coating films, the same ammonia-catalyzed oxidative deodorization performance test as in Example 2 was conducted.

The results are shown in (Table 8). As shown in (Table 8), by including cerium oxide in the coating film, the catalytic oxidation activity for ammonia can be improved.

When the content of cerium oxide exceeds 15 wt%, the oxidative decomposition characteristics of the catalyst begin to deteriorate, and when it is less than 2 wt%, a sufficient addition effect of cerium oxide cannot be obtained. Therefore, the desirable content of cerium oxide is It is 2 to 15 wt% of the solid content (coating film) in the paint.

[0062]

[Table 8]

(Example 9) Barium oxide in various amounts was added to the coating material A of Example 1, and the same amount of coating film as the coating material A was applied to the surface of the quartz glass plate. Coating films having different barium oxide contents as shown in Table 9 were formed in the same manner as in Example 1. The increase in barium oxide in the paint was prepared by reducing the amount of alumina.

An ammonia-catalyzed oxidative deodorization performance test was performed on these coating films in the same manner as in Example 8. The adhesion test was performed in the same manner as in Example 5. As the barium oxide source of the present invention, in addition to oxides, hydroxides, nitrates, carbonates and other compounds that thermally decompose into barium oxide by heating can be used. The results are shown in (Table 9).

As shown in (Table 9), by including barium oxide in the paint, the catalytic oxidation activity for ammonia can be improved.

When the content of barium oxide exceeds 5% by weight, the adhesion property of the coating film begins to deteriorate, and when it is less than 0.5% by weight, a sufficient addition effect of barium oxide cannot be obtained. The amount is 0.5 to 5 wt% of the solid content in the paint.

[0067]

[Table 9]

(Example 10) Titanium oxide in various proportions was added to the coating material A of Example 1, and the same amount of coating film A as the coating film A was formed on the surface of the quartz glass plate in the same manner as in Example 1. The amount of solid titanium oxide contained in the paint was varied as shown in Table 10 to form coating films. The increased amount of titanium oxide in the paint was prepared by reducing the amount of alumina.

Ammonia was selected as an odorant for these coating films, and this ammonia purification test was conducted in the same manner as in Example 6. The adhesion test was performed in the same manner as in Example 2.

The results are shown in (Table 10). As shown in (Table 10), by including titanium oxide in the paint, the catalytic oxidation activity of the formed coating film with respect to ammonia can be improved.

When the content of titanium oxide exceeds 15 wt%, the adhesion property of the coating film begins to deteriorate, and when it is less than 3 wt%, a sufficient addition effect of titanium oxide cannot be obtained. Therefore, the desirable content of titanium oxide is 3 to 15 wt% of solid content in paint
Is.

[0072]

[Table 10]

(Example 11) Paint A prepared in Example 1
In the paint, chloroplatinic acid and palladium chloride in the paint are used as a paint D containing 9 g of a single noble metal salt of chloroplatinic acid as Pt, a paint E containing 9 g of palladium chloride as Pd and a paint F containing 9 g of rhodium nitrate as Rh, and nitric acid. A coating material G containing 9 g of ruthenium as Ru was prepared. With respect to the coating films D, E, F, G and the coating film A formed on the quartz glass plate by using the coating film forming method similar to the coating film A of Example 1 using these paints, The indicated ammonia catalyst oxidative deodorization performance was investigated. The results are shown in (Table 11).

As is clear from (Table 11), it is desirable that Pt and Pd are contained as the noble metal, and more desirably, the coating material A in which Pt and Pd are mixed is most desirable.

[0075]

[Table 11]

[0076]

As described above, the coating film formed from the coating composition of the present invention prevents the odor of the atmosphere in which the coating film is placed and harmful gases such as cigarette smoke from adsorbing the catalyst and the catalyst. Deodorized by oxidative decomposition. Therefore, by forming the coating film on various equipments and the wall surface in the room, it is possible to provide a comfortable environment with less odorous substances.

Continuation of front page (51) Int.Cl. ⁶ Identification number Office reference number FI technical display area C09D 5/00 PSD // C01B 39/02

Claims (4)

[Claims] 1. A paint comprising at least one of zeolite and magnesium silicate, activated alumina, a platinum group metal salt, an inorganic binder, and a dispersion medium. 2. The paint according to claim 1, wherein the zeolite is a copper-containing zeolite. 3. The paint according to claim 1, wherein the inorganic binder is colloidal silica, and the content thereof is 10 to 40 wt% of the solid content in the paint. 4. At least one of zeolite and magnesium silicate, and activated alumina carrying a platinum group catalyst,
A paint composed of an inorganic binder and a dispersion medium.