JPH04290547A - Water-absorbing deodorant - Google Patents

Abstract

PURPOSE:To obtain an excellent water-absorbing deodorant by producing a sol containing silicate and metal salt, neutralizing the sol with an acid to obtain a silicic acid gel structure, and incorporating bentonite and a complex of isobutyne-maleic acid anhydride copolymer, and polyethylene imine into the gel structure. CONSTITUTION:ph of an aq. soln. containing silicate and metal salt is controlled to 9-11 and this soln. is kept at 45-70 deg.C to produce a sol containing silicate and metal salt. This sol is neutralized with an acid to obtain a gel containing metal salt in its silicic acid gel structure. Then bentonite and a complex of isobutyne-maleic acid anhydride copolymer and polyethylene imine are incorporated into the gel. This water-absorbing deodorant has large ability to adsorb and remove various kinds of bad odor gases such as hydrogen sulfide, ammonia, mercaptan, etc. Since the metal salt is included in the glass structure of the silicic acid gel, the deodorant is harmless even when a human body directly touches it. Moreover, this deodorant is suitable as a treating agent for excretion of pets.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention relates to a water-absorbing deodorizing agent and a pet excrement treatment agent using the same. It is a deodorizing agent that has excellent adsorption properties and high water absorption, and is particularly suitable for treating pet excrement.

0002

2. Description of the Related Art In recent years, with the spread of pets, the odor of pets and their excrement indoors has become a problem. The biggest source of pet odor is excrement, but pets are often kept indoors 24 hours a day,
This is especially problematic in such environments.

[0003] As the sand used for treating pet excrement, conventional sand, crushed bentonite, zeolite, paper sand, porous sand, etc. have been used. However, although bentonite has the property of solidifying with urine, it does not have deodorizing properties. Zeolite has the ability to deodorize ammonia and the like, but because it does not solidify, it is difficult to select and remove only the parts contaminated with urine and the like, and it is also inconvenient to handle. Attempts have been made to use a molded mixture of zeolite and bentonite, but the molded particles tend to disintegrate and have low water absorption, making them impractical.

0004

[Problem to be solved by the invention] When treating pet excrement, etc., the urine is absorbed by water-absorbing polymers and instantly solidifies.It also has a high adsorption capacity for ammonia, etc., and releases odor even if left alone. The purpose is to provide a water-absorbing deodorizing agent that is effective even when used in a smaller amount than conventionally used sand or bentonite.

[0005]

[Means for Solving the Problems] In order to solve the above-mentioned problems, the present inventors conducted research focusing on the fact that a gel in which a metal salt is encapsulated in a silicate gel has excellent deodorizing properties. Furthermore, bentonite and isobutene are added to these gels.
We have discovered that a molded product containing a complex of maleic anhydride copolymer and polyethyleneimine is suitable for treating malodorous substances with a high moisture content, and based on this finding, we have arrived at the present invention.

That is, one or two selected from the group consisting of silicates and metal salts of silver, aluminum, titanium, vanadium, chromium, manganese, iron, cobalt, nickel, tin, copper, zinc, cadmium, and lead. The aqueous solution containing the above metal salts was adjusted to pH 9-11 and heated to 45-70°C.
A sol containing a silicate and a metal salt is produced, and then neutralized with an acid, and bentonite and isobutene-maleic anhydride are added to the resulting gel containing a metal salt inside the silicate gel structure. These are a water-absorbing deodorizer made by mixing a complex of an acid copolymer and polyethyleneimine, and a pet excrement treatment agent made by molding the water-absorbing deodorizer.

The present invention will be explained in detail below. Note that the term silicate includes not only silicic acid salts but also silicic acid, silicic anhydride, etc. produced in the process of producing silicic acid gel.

The water-absorbing deodorizing agent of the present invention is a composition having a silicate gel structure consisting of a silicate and a metal salt. Although a wide variety of silicates can be used as raw materials for the deodorizing agent of the present invention, preferred examples include water glass, silicon hydroxide, silica sol, and silica gel that dissolve in an alkaline aqueous solution.

The metal salt used in the present invention is one or two selected from the group consisting of silver, aluminum, titanium, vanadium, chromium, manganese, iron, cobalt, nickel, tin, copper, zinc, cadmium, and lead. It is necessary to use the above metal salts. The type of salt is not particularly limited and a wide variety of salts can be used, but sulfates, chlorides, nitrates, acetates and the like are preferred. Other oxides of these metals can also be used. These metal salts or metal oxides may be used alone or in combination.

The content of the metal salt is not particularly limited, but the weight ratio of the silicate (a) (in terms of SiO2) and the metal salt (b) (in terms of metal) is (a):(b)=5:1 to 20. :1
is preferred. Even if the ratio of the metal salt becomes higher than this, the adsorptivity is not improved much, and if the metal salt content is lower than this, the adsorption of malodorous substances decreases, which is not preferable.

In order to encapsulate a metal salt inside the silicate gel structure, it is necessary to dissolve the metal salt in an alkaline aqueous solution of a silicate and grow a silicate sol containing the metal salt in the solution.

To adjust the pH of the aqueous solution of silicate and metal salt, alkaline compounds such as sodium hydroxide, calcium hydroxide, barium hydroxide, ammonia, etc. can be used. Further, in order to neutralize this alkaline aqueous solution, acids such as hydrochloric acid, sulfuric acid, nitric acid, acetic acid, etc. can be used. However, when adjusting or neutralizing the pH, alkaline compounds or acids that produce water-insoluble salts are not preferred.

In order to grow a silicic acid sol containing a metal salt, the pH of the solution is adjusted to 9 to 11, and the pH of the solution is adjusted to 50 to 11.
Preferably, the temperature is maintained at 70°C. Under such conditions, the silicic acid molecules in the solution gradually polymerize to form polysilicic acid molecules, and a sol containing the metal salt therein is formed.

[0014] At this time, the pH and temperature of the solution are closely related to the composition and structure of the generated sol, and furthermore, they have a very large effect on the microstructure such as the specific surface area, pore volume, and pore distribution of the deodorizer of the present invention. has. The hydroxyl groups contained in the solution act as a polymerization catalyst for silicic acid molecules, so if the pH is lower than 9, the concentration of catalytic hydroxyl groups is low, so polymerization does not proceed, that is, the sol does not grow. Therefore, even if a deodorizing agent is prepared by neutralizing the solution, precipitating a gel, and drying it, the pore structure is not developed, the specific surface area is small, and the deodorizing property is also low, which is not preferred in practice.

Furthermore, when the pH is higher than 11, polymerization tends to be inhibited and the rate of sol production tends to decrease. This is thought to be due to an increase in the hydroxyl group concentration, which increases the charge on the polysilicic acid molecules and increases the repulsion between the molecules.

There is also a close relationship between the growth rate of the silicic acid sol and the solution temperature, which is preferably maintained within the range of 50 to 70°C. The higher the temperature of the solution, the faster the polymerization rate;
The sol generated in the solution has a loose structure. For this reason, the specific surface area of the deodorizer decreases, and its ability to adsorb bad odors decreases. When the temperature decreases, the polymerization rate slows down, and the sol formed in the solution has a dense structure with few pores formed.
Therefore, the specific surface area becomes very small, which lowers the adsorptivity, which is not preferable.

Next, by neutralizing the solution, the silicic acid sol containing the metal salt undergoes a phase transition to a gel and precipitates. The pH during neutralization is not particularly limited, but is preferably in the range of 6 to 7. The gel can be separated by filtering off the sediment and drying it.

The specific surface area of the gel having a porous structure thus obtained is approximately 500 to 700 m2/
g, and when the specific surface area decreases, the adsorption ability for malodorous gases decreases significantly. This is due to the decrease in specific surface area.
This is thought to be due to a decrease in physical adsorption.

[0019] The silicic acid gel containing the above metal salt has 500
It exhibits good adsorption up to temperatures around ℃ and has excellent thermal stability.

[0020] The metal salt contained in the deodorizer of the present invention is
Since it is encapsulated in a silica gel glass structure, it will not elute to the outside even if it comes into direct contact with water or acid. Therefore, there is no harm even if pets etc. come into contact with it. Furthermore, even when the metal salt is included in the glass structure, the adsorption ability for malodorous gases such as ammonia does not decrease, so it can be used in many applications as a deodorizing agent.

The water-absorbing deodorizing agent of the present invention is prepared by mixing bentonite, an isobutene-maleic anhydride copolymer, and a polyethyleneimine complex into the silicic acid gel containing the metal salt obtained as described above. can get.

In addition to bentonite, clay materials such as kaolinite and montmorillonite can be used as the bentonite of the present invention. Further, as the silicate, water glass, silica gel, silica sol, etc. can be used as a raw material for the molded deodorizer.

The complex of isobutene-maleic anhydride copolymer and polyethyleneimine used in the present invention can be prepared by dissolving a copolymer of isobutene and maleic anhydride in an alkaline aqueous solution and adding polyethyleneimine to the mixture. is made into a complex by ionic bonds. Since the complex can contain a large number of water molecules inside the molecular structure of the polymer, it has a high water absorption capacity of several hundred times the water absorption ratio to the solid weight. Other water-absorbing polymers were also tested in place of this polymer, but the results showed that both the water absorption of the deodorizer and the adsorption of malodorous gases were significantly reduced.

[0024] The water-absorbing deodorizer, which is made of a gel containing a metal salt in the silicic acid gel structure, bentonite, and a mixture of a complex of isobutene-maleic anhydride copolymer and polyethyleneimine, can be used as it is in powder form, and can also be used as is. It can also be used in any shape, such as a molded product or granule. When used as a pet excrement treatment agent, powder is unfavorable in terms of handling because it easily scatters, and molded products are preferred.

The mixture of the invention contains hydrogen sulfide, ammonia,
It has great ability to adsorb and remove foul-smelling gases such as mercaptans and amines. These foul-smelling gases exist in ordinary living spaces, and ordinary activated carbon cannot completely remove them because of its relatively low adsorption properties. Therefore, although it is effective as a general deodorizing agent, it is particularly suitable as a treatment agent for pet odor or excrement, in combination with its water absorption properties.

[0026]

[Operation] The molded deodorizer of the present invention has a pore structure based on silica gel and has a specific surface area of several 100 m2/g, and one or more metal salts or metal oxides contained therein. It consists of Therefore, it is thought that the synergistic effect of the physical adsorption of silica gel and bentonite and the chemical action of metal salts etc. exhibits high adsorption properties for bad odors. Furthermore, since it contains a complex of isobutene-maleic anhydride copolymer and polyethyleneimine, which has a very high water absorption ratio, and bentonite, it can instantly solidify pet urine, etc., further enhancing its odor removal function. .

[0027]

[Examples] The present invention will be explained in more detail below with reference to Examples.

(Example 1) 25 parts by weight of water, water glass (
Add 10 parts by weight of zinc sulfate (in terms of metal zinc, the same applies below) and bring the pH to 1 with NaOH.
The solution was stirred to obtain a homogeneous solution, and the solution was maintained at 60° C. for 15 minutes to ripen. Next, add 40% H2SO4 while stirring to adjust the pH to 7.
After filtering and washing the product, it was dried at 200° C. for 3 hours to obtain a silicic acid gel containing zinc sulfate. The BET specific surface area of this gel was 530 m2/g.

80 parts by weight of bentonite was added to this silicic acid gel.
After adding 1 part by weight of a complex of isobutene-maleic anhydride copolymer and polyethyleneimine and mixing well, the mixture was formed into cylindrical pellets with a diameter of 3 mm using an extruder.

The water absorption rate and amount of water absorbed by this deodorizer, the adsorption amount of malodorous gases such as hydrogen sulfide, ammonia, methyl mercaptan, sulfur dioxide gas, and aldehyde, and the hardness of the pellets were measured.

The method for measuring the amount of malodorous gas adsorbed is as follows. After putting 100 mg of the adsorbent into a vial with an internal volume of 120 ml and sealing it with a rubber stopper, a predetermined amount of malodorous gas component is injected into the vial using microsiridine. Two hours after the gas was injected, the air in the vial was extracted using microsilidine, and the gas concentration was analyzed using a gas chromatograph. In addition, the hardness of the pellets was measured using a Kiya type hardness meter.

The results are shown in Table 1.

[0033]

[Table 1]

(Examples 2 to 4) A mixture of silicic acid gel containing zinc sulfate, bentonite, and a complex of isobutene-maleic anhydride copolymer and polyethyleneimine having the composition shown in Table 2 was used. An adsorbent was prepared under the same conditions as in Example 1, and made into cylindrical pellets with a diameter of 2 mm using an extruder.

The water absorption rate and amount of the deodorizer obtained above, the adsorption amount of malodorous gases such as hydrogen sulfide, ammonia, methyl mercaptan, sulfur dioxide gas and aldehyde, and the hardness of the pellets were measured.

The results are shown in Table 2.

[0037]

[Table 2]

(Comparative Examples 1 and 2) When a deodorizing agent was prepared in the same manner as in Example 1 except that the complex of isobutene-maleic anhydride copolymer and polyethyleneimine was not used (Comparative Example 1) and water absorption starch as a polymer
In addition to using acrylic acid gel, when a deodorizer was prepared in the same manner as in Example 1 (Comparative Example 2), the water absorption rate,
The amount of water absorbed, the amount of adsorption of malodorous gases such as hydrogen sulfide, ammonia, methyl mercaptan, sulfur dioxide gas, and aldehydes, and the hardness of the pellets were measured.

The results are shown in Table 1.

[0040]

Effects of the Invention The water-absorbing deodorizing agent of the present invention has a high ability to adsorb and remove malodorous gases such as hydrogen sulfide, ammonia, mercaptans, and amines, which are the main malodors present in daily living spaces, and has a high ability to adsorb and remove malodorous gases such as hydrogen sulfide, ammonia, mercaptans, and amines. Since it is contained inside the silicate gel glass structure, it is harmless even if it comes into direct contact with humans or animals.

Furthermore, since it also contains bentonite and a water-absorbing polymer, it has the ability to instantly solidify when water is added, making it suitable for pet excrement treatment agents, which have recently become a frequent problem.

Claims (2)

[Claims] [Claim 1] One or two selected from the group consisting of silicates and metal salts of silver, aluminum, titanium, vanadium, chromium, manganese, iron, cobalt, nickel, tin, copper, zinc, cadmium, and lead. The pH of the above metal salt-containing aqueous solution was adjusted to 9 to 11, maintained at 45 to 70°C to generate a sol containing silicate and metal salt, and then neutralized with acid to obtain the sol. A water-absorbing deodorizing agent made by mixing bentonite, an isobutene-maleic anhydride copolymer, and a polyethyleneimine complex into a gel containing a metal salt inside the silicic acid gel structure. [Claim 2] One or two selected from the group consisting of silicates and metal salts of silver, aluminum, titanium, vanadium, chromium, manganese, iron, cobalt, nickel, tin, copper, zinc, cadmium, and lead. The pH of the above metal salt-containing aqueous solution was adjusted to 9 to 11, maintained at 45 to 70°C to generate a sol containing silicate and metal salt, and then neutralized with acid to obtain the sol. A pet excrement treatment agent made by molding a mixture of bentonite, an isobutene-maleic anhydride copolymer, and a polyethyleneimine complex into a gel containing a metal salt inside a silicic acid gel structure.