JPH0620541B2 - Ethylene gas adsorbent - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to an ethylene gas adsorbent, and more specifically,
The present invention relates to an ethylene gas adsorbent that is safe, harmless in mass production, and has excellent ethylene gas adsorption capacity.

<Prior Art> Ethylene gas has been pointed out as one of harmful substances that promote ripening of fruits and vegetables such as apples, bananas, tomatoes, pears, melons, asparagus, and spinach, and cause aging and decay. This ethylene gas is said to be generated as the respiration of fruits and vegetables progresses.Especially for fruits and vegetables that generate a large amount of ethylene gas such as asparagus and spinach, it is efficient to remove ethylene gas from the storage atmosphere. The task is to do well.

Therefore, various ethylene gas adsorbents have been proposed so far, and among them, the main ones that have been put into practical use include, for example, activated carbon, Otani stone, and zeolite.

<Problems to be Solved by the Invention> However, many of the above-mentioned conventional ethylene gas adsorbents have a low ethylene gas adsorption capacity.

The present invention has been made to solve the problems that the conventional ethylene gas adsorbents have in view of the above circumstances, and the purpose thereof is to have an excellent ethylene gas adsorption capacity, To provide an ethylene gas adsorbent that does not contain a metal that is highly toxic to the human body, and that has an adsorbing capacity that can be sufficiently put into practical use even after moisture absorption where the adsorbing capacity usually decreases, and that is excellent in safety and mass productivity. It is in.

<Means and Actions for Solving the Problems> The ethylene gas adsorbent according to the present invention for achieving the above object has a specific surface area where it has not been known at all that ethylene gas can be effectively adsorbed. It contains 50 m ² / g or more of hydrous titanium oxide and / or anhydrous titanium oxide as an active ingredient.

The specific surface area of hydrous titanium oxide and anhydrous titanium oxide is 50 m ²
When the specific surface area, which is the amount showing the characteristics as an adsorbent, is less than 50 m ² / g, the contact area with ethylene gas is small, so that sufficient adsorption capacity may not be achieved. Because there is.

As components other than the active component, Al, Si, P, B, Cr, Mn, Fe, as a diluting component or as a component for preventing reduction of the specific surface area of the adsorbent after sintering,
A water-containing or anhydrous oxide such as Co, Ni, Sn, Zr, Nb, Mo, Sb or W may be contained as an auxiliary agent.
It is preferable that these auxiliary agents are usually added in an amount of 5% by weight or less based on the total weight of the ethylene gas adsorbent. This is because if it exceeds 5% by weight, the content of the above-mentioned active ingredient in the adsorbent becomes small, and the amount of adsorbed ethylene gas per weight decreases.

As the ethylene gas adsorbent according to the present invention, hydrous titanium oxide or anhydrous titanium oxide may be used alone or in combination of two or more kinds. Furthermore, conventionally known Otani stone,
You may use together with various ethylene gas adsorbents, such as a zeolite.

The ethylene gas adsorbent according to the present invention can be used in various forms such as powder, granules and pellets.
For example, it can be used by dispersing it in a solvent, or by kneading an ethylene adsorbent with a resin or the like and shaping it into a sheet shape, a film shape, or the like.

The adsorbent of the present invention formed into a film can be used as a freshness keeping film for keeping the freshness of fresh food such as fruits and vegetables.

That is, ripening of fruits and vegetables progresses even after harvest,
Phenomena such as discoloration, softening and decay occur. This additional ripening is accelerated by ethylene gas generated by the breathing action of fruits and vegetables.

The adsorbent of the present invention is suitable for use in delaying or preventing the ripening of fruits and vegetables by selectively and promptly adsorbing ethylene gas generated from fruits and vegetables and the like,
Enables long-term storage and freshness preservation of fresh food such as fruits and vegetables. In addition to this, it goes without saying that the adsorbent of the present invention can be used in various industrial fields and analytical fields.

<Example> Hereinafter, the present invention will be described based on examples.

A. Preparation of Adsorbent of the Present Invention (Example 1) TiO ₂ concentration of 100 obtained by dissolving titanium tetrachloride in water
Ammonia water having a concentration of 28% was added to 500 g of a titanic acid acidic solution (g / m) with stirring to adjust the pH of the solution to 7.
Adjusted to 0. The pH-adjusted solution was stirred and mixed for an additional 20 minutes, and then the pH was adjusted again to 7.0.
It was adjusted. The solution after this readjustment is filtered, the obtained filtered product is washed with water, repulped, and then dried with hot air by a dryer (inlet temperature: 300 ° C., outlet temperature: 110 ° C.) to hydrate the water as an adsorbent of the present invention. Titanium (Sample 1) was produced.

(Example 2) The hydrous titanium oxide (Sample 1) obtained in Example 1 was fired at a temperature of 400 ° C for 3 hours using an electric furnace to obtain anhydrous titanium oxide (Sample 2) as the adsorbent of the present invention. It was

(Example 3) TiO ₂ obtained by diluting a sulfuric acid solution of metatitanic acid with water
After heating 500 m of a titanyl sulfate acidic solution having a concentration of 100 g / 70 ° C., 28% ammonia water was added with stirring and mixing to adjust the pH of the solution to 7.0. The pH-adjusted solution was stirred and mixed for a further 20 minutes, and then the solution was mixed.
The pH was adjusted again so that the pH was 7.0. The solution after this readjustment is filtered, and the obtained filtered product is washed with water and repulped,
Further, hot air drying (inlet temperature: 300 ° C., outlet temperature: 110 ° C.) was performed with a dryer to prepare hydrous titanium oxide (Sample 3) as the adsorbent of the present invention.

(Example 4) The hydrous titanium oxide (Sample 3) obtained in Example 3 was calcined in an electric furnace at a temperature of 500 ° C for 3 hours to obtain anhydrous titanium oxide (Sample 4) as an adsorbent of the present invention. It was

(Example 5) TiO ₂ concentration 100 obtained by dissolving titanium tetrachloride in water
To 500 g of g / titanic acid acidic solution, 25 m of Al ₂ O ₃ concentration of 50 g / aluminum chloride solution was added and mixed, and this mixed solution was added to 28% concentration of ammonia water while stirring and mixing in water to prepare a solution of The pH was adjusted to 7.0. The pH-adjusted solution was stirred and mixed for a further 20 minutes, and then the pH was adjusted again so that the pH of the solution became 7.0. The solution after this readjustment is filtered, the obtained filtered product is washed with water, repulped, and then dried with hot air by a dryer (inlet temperature: 300 ° C., outlet temperature: 110 ° C.) to hydrate the water as an adsorbent of the present invention. A material composition (TiO ₂ : 100 parts by weight, Al ₂ O ₃ : 2.5 parts by weight) (Sample 5) was prepared.

(Example 6) The hydrous titanium oxide (Sample 5) obtained in Example 5 was calcined in an electric furnace at a temperature of 600 ° C for 3 hours to give an anhydrous oxide composition (Sample 6) as an adsorbent of the present invention. Got

(Example 7) A TiO ₂ concentration of 100 obtained by dissolving titanium tetrachloride in water
To 500 m of g / titanic acid acidic solution, 150 m of ZrO ₂ concentration of 50 g / zirconyl chloride solution was added and mixed, and this mixed solution was added to 28% concentration of ammonia water while stirring and mixing in water to adjust the pH of the solution. Adjusted to 7.0. The pH-adjusted solution was stirred and mixed for a further 20 minutes, and then the pH was adjusted again so that the pH of the solution became 7.0. The solution after this readjustment is filtered, the obtained filtered product is washed with water, repulped, and then dried with hot air by a dryer (inlet temperature: 300 ° C., outlet temperature: 110 ° C.) to hydrate the water as an adsorbent of the present invention. A material composition (TiO ₂ : 100 parts by weight, ZrO ₂ : 5 parts by weight) (Sample 7) was prepared.

(Example 8) Niobium pentachloride (5.1 g) and titanium tetrachloride (238 g) were mixed with methanol (200 m), and the mixed solution was added to 28% aqueous ammonia with stirring and mixing in water to adjust the pH of the solution to 7. Adjusted to 0. Hereinafter, a hydrous oxide composition of titanic acid and niobic acid obtained in the same manner as in Example 5 as the adsorbent of the present invention (TiO ₂ : 100 parts by weight, Nb ₂ O ₅ :
5.0 parts by weight) (Sample 8) was obtained.

(Example 9) TiO ₂ concentration 100 obtained by dissolving titanium tetrachloride in water
g / titanic acid acidic solution (500 m) and Sb ₂ O ₃ concentration of 50 g / antimony trichloride solution (25 m) were mixed, and this mixed solution was added to 28% concentration of ammonia water while stirring and mixing in water to adjust the pH of the solution. Was adjusted to 7.0. Hereinafter, the hydrous oxide composition of titanic acid and antimonic acid obtained in the same manner as in Example 5 was fired for 3 hours at a temperature of 500 ° C. in an electric furnace to obtain an anhydrous oxide composition as the adsorbent of the present invention. (TiO ₂ : 100 parts by weight, Sb ₂ O ₃ : 2 :.
5 parts by weight) (Sample 9) was obtained.

(Example 10) TiO ₂ concentration of 100 obtained by dissolving titanium tetrachloride in water
g / titanic acid acidic solution 500 m and WO ₃ concentration 50
25 g of an ammonium orthotungstate solution of g / 25 g was mixed, and this mixed solution was added to 28% aqueous ammonia while stirring and mixing in water to adjust the pH of the solution to 7.0. Hereinafter, the hydrous oxide composition of titanic acid and tungstic acid obtained in the same manner as in Example 5 was subjected to 500 using an electric furnace.
After being calcined at a temperature of 3 ° C. for 3 hours, the anhydrous oxide composition (TiO ₂ : 100 parts by weight, WO ₃ : 2: 2.
5 parts by weight) (Sample 10) was obtained.

(Example 11) TiO ₂ obtained by diluting a sulfuric acid solution of metatitanic acid with water
After heating 500 m of a titanyl sulfate acidic solution having a concentration of 100 g / to 70 ° C., 5 m of a sodium silicate solution having a SiO ₂ concentration of 50 g / m was added to this solution while adding 28% aqueous ammonia solution to adjust the pH of the solution to 7 Adjusted to 0.0. Thereafter, the hydrous oxide composition of titanic acid and silicic acid obtained in the same manner as in Example 1 was fired in an electric furnace at a temperature of 600 ° C. for 3 hours to obtain an anhydrous oxide composition as the adsorbent of the present invention. (T
io ₂ : 100 parts by weight, SiO ₂ : 0.5 parts by weight) (Sample 11) was obtained.

(Example 12) A repulped product (hydrated titanium oxide) TiO ₂ converted to 40, which was prepared in the same manner as in Example 3 and obtained in the intermediate step thereof, after filtration and washing with water.
g to make a slurry having a TiO ₂ concentration of 100 g /, and to this slurry, an orthophosphoric acid solution 12 having a P ₂ O ₅ concentration of 50 g /
After adding m and stirring and mixing well, hot air drying with a spray dryer (inlet temperature: 300 ° C, outlet temperature 110 ° C)
Then, a hydrous oxide composition of titanium oxide and phosphorus pentoxide as the adsorbent of the present invention (TiO ₂ : 100 parts by weight, P ₂ O
₅ : 1.5 parts by weight) (Sample 12) was prepared.

Except Example ₁₃ for the use of P 2 _{O 5} concentration 50g / _B 2 _{O 3} in place of the orthophosphoric acid solution 12m of concentration 50 g / boric acid solution 16m, in the same manner as in Example 12, no hydroxide composition A product (TiO ₂ : 100 parts by weight, B ₂ O ₃ : 2.0 parts by weight) (Sample 13) was prepared.

(Example 14) An anhydrous oxide composition was obtained in the same manner as in Example 12 except that 8 m of an ammonium molybdate solution having a MoO ₃ concentration of 50 g / was used instead of the orthophosphoric acid solution of 12 g having a P ₂ O ₅ concentration of 50 g /. Thing (TiO ₂ : 100 parts by weight, Mo
O ₃ : 1.0 part by weight) (Sample 14) was prepared.

Obtained in Example 15 Example 8, hydrous composition titanate niobate accommodate the water downwards _(TiO 2: 5.0 parts by weight: 100 parts by _weight, Nb ₂ O 5) Placed above the sealed container and allowed to absorb moisture for 1 week in a high humidity atmosphere, and the water content was 18.
A 6 wt% hygroscopic oxide composition (Sample 15) was prepared.

B. Adsorption performance test: Specific surface area of samples 1 to 14 and comparative sample 1 17 m ² /
Each ethylene adsorption capacity was measured for g of Otani stone.

The results are shown in Table 1.

The specific surface area (m ² / g) in the table was obtained by the BET nitrogen adsorption method, and the ethylene adsorption amount was measured at a temperature of 24
It is measured by using a BET surface area measuring device under the conditions of ° C and a pressure of 203 mmHg.

As is clear from Table 1, Samples 1 to 14 according to the present invention
It can be seen that each of them has an ethylene gas adsorption capacity that is several times better than that of Comparative Sample 1.

C. Adsorption performance test after moisture absorption The hydrous oxide composition of titanic acid and niobic acid (TiO ₂ : 100 parts by weight, Nb ₂ O ₅ : 5.0 parts by weight) obtained in Example 8 (Sample 8) and the above The ethylene gas adsorption capacity of the sample 15 was measured to compare the adsorption performance before and after moisture absorption.
In addition, the ethylene gas adsorption capacity (mg / g) was measured using Otani stone, which had a specific surface area of 17 m ² / g and a water content of 3.8% and was made to absorb moisture by the same method as in Example 15, as a comparative sample 2. . The results are shown in Table 2. The ethylene gas adsorption amount of Otani stone before moisture absorption in the table is 1st for convenience of comparison.
It is transcribed from the table.

As is clear from the above table, the sample 8 according to the present invention has an ethylene gas adsorption capacity even after moisture absorption, whereas the comparative sample Otaniishi has no ethylene gas adsorption capacity after moisture absorption. .

<Effect of the Invention> The ethylene gas adsorbent according to the present invention has excellent ethylene gas adsorbing ability regardless of water content and anhydrous, and also has ethylene gas adsorbing ability even after moisture absorption. Play.

Claims (1)

[Claims] 1. An ethylene gas adsorbent containing, as an active ingredient, hydrous titanium oxide and / or anhydrous titanium oxide having a specific surface area of 50 m ² / g or more.