JP4830177B2 - Soil modifier and method for producing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To effectively utilize a high-molecular weight material containing acrylonitrile-styrene or acrylonitrile-styrene-conjugated diene or one of their used materials as a higher additional value substance. SOLUTION: The objective method of producing soil conditioner comprises and acid treatment step where a plolymer material including acrylonitrile, styrene and/or a conjugated diene as the constitution units is treated with an acid and a salt formation step where the acid groups formed in the polymer material during the acid treatment and the excessively remaining acid used in the acid treatment are converted into a corresponding salt.

Description

【００７４】
表１から明らかなように、実施例１〜実施例４で得られた固形物が混合された土壌での、６月上旬におけるナスの平均葉数は、いずれも、比較例１及び比較例２の場合に比べて多くなっていることがわかる。これは、土壌中に混合された固形物が、水分を保持する機能を有し、ナスの生育を促進したためと考えられる。特に、その効果は、残留遊離酸塩の量が、固形物に対して０．０１重量％以上のときに良好である。
【００７５】
従って、アクリロニトリルとスチレン又は共役ジエンとを構成ユニットとして含有する高分子材料に対して酸処理を行い、それに引き続いて塩形成を行うことにより得られた高分子体と、当該酸の残留遊離酸の塩との混合体は、土壌改質剤として優れた性能を示すことがわかった。
【００７６】
【発明の効果】
本発明では、植物生育を促進する土壌改質剤を得ることができる。この土壌改質剤は、使用済みとなった廃プラスチック材から製造することができるため、資源の有効利用につながり、地球の環境保全に貢献することができる。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a soil modifier and a method for producing the same.
[0002]
[Prior art]
Examples of the resin containing acrylonitrile and styrene and / or conjugated diene include polystyrene (ABS (acrylonitrile-butadiene-styrene) resin, SAN (styrene-acrylonitrile) resin, ASA (acrylonitrile-styrene-acrylate) resin). And a synthetic rubber of NBR (acrylonitrile-butadiene rubber). These resins are relatively inexpensive, and in particular, the former polystyrene resin is excellent in properties such as rigidity, dimensional stability, and processability, and therefore, covers and cases for various uses, casings of electrical equipment and automobiles, It is widely used as a resin material for various component materials.
[0003]
Under such circumstances, these materials are expected to be further expanded in application, and studies on reforming to those with higher added value are desired.
[0004]
In addition, products using the above-mentioned materials are generated in large quantities as waste materials as the production amount increases. In recent years, the amount of waste materials made of these materials has also been increasing, and the need for effective use of waste materials has increased due to the growing interest in global environmental conservation.
[0005]
[Problems to be solved by the invention]
By the way, polymer waste materials are roughly divided into three types of methods: landfilling, incineration, and remelting. Among them, in Japan, landfill and incineration account for about 90% of the total, and most of them are not recycled.
[0006]
In addition, as a recycling method of this polymer waste material, heating, melting, and remolding (however, only thermoplastic resin) is generally performed. At this time, quality degradation due to heat (decrease in molecular weight, resin) Etc.), contamination of foreign matters such as dust, or mixing of resins containing various colorants required color matching. As described above, when polymer waste is recycled by heating and melting, the processing technique and cost have been a major obstacle.
[0007]
The present invention has been proposed in view of the above-described conventional situation, and these acrylonitrile and styrene or conjugated diene-containing polymer materials or used waste materials are effectively used as higher value-added materials. It aims at providing the soil modifier used and its manufacturing method.
[0008]
[Means for Solving the Problems]
  In the soil modifier of the present invention, an acid group is formed in the polymer material by treating the polymer material containing acrylonitrile and styrene and / or conjugated diene as constituent units with an acid. Containing a polymer in which the acid group is made into a salt, and a salt of the residual free acid of the acid,The acid group is a sulfonic acid group, the salt is any of a sodium salt, an ammonium salt, and a potassium salt, and the acid group is 25 mol% or more and 42 mol% or less with respect to all units of the polymer. The residual free acid salt is contained in a proportion of 1.2% by weight or more and 1.9% by weight or less based on the polymer.
[0009]
  In the soil conditioner of the present invention as described above, the polymer material is treated with an acid, so that the polymer material containsSulfonic acidAs the group is formedSulfonic acidGroupDepending on sodium salt, ammonium salt or potassium saltA polymer formed as a salt and the residual free acid of the acidSodium salt, ammonium salt or potassium saltContainingThe acid group is 25 mol% or more and 42 mol% or less with respect to all units of the polymer, and the residual free acid salt is 1.2 wt% or more and 1.9 wt% with respect to the polymer. % Or lessTherefore, it exhibits good water absorption and soil improvement.
[0010]
  The method for producing a soil modifier of the present invention includes an acid treatment step of forming an acid group by treating a polymer material containing acrylonitrile and styrene and / or conjugated diene as constituent units with an acid, and the acid A chlorination treatment step for salting the acid groups formed in the polymer material in the treatment step and the residual free acid of the acid,The acid group is a sulfonic acid group, and the salt is any one of a sodium salt, an ammonium salt, and a potassium salt, and in the acid treatment step, the acid group is added to all units of the polymer. 25 mol% or more and 42 mol% or less are introduced, and the residual free acid salt is contained in a proportion of 1.2 wt% or more and 1.9 wt% or less with respect to the polymer. The agent is manufactured.
[0011]
  In the method for producing the soil modifier of the present invention as described above, the polymer material is treated with an acid.SulfoneForming acid groups, andSulfoneAcid groupOne of sodium salt, ammonium salt, potassium saltSalt and residual free acidSodium salt, ammonium salt or potassium saltContaining, sulfoneThe acid group is 25 mol% or more and 42 mol% or less with respect to all units of the polymer, and the residual free acid salt is 1.2 wt% or more and 1.9 wt% or less with respect to the polymer. Contained in proportionSince the soil modifier is obtained, the polymer material can be effectively used.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below.
[0013]
As a result of intensive studies with the inventors that have achieved the above-mentioned object, the present inventor formed an acid treatment of a polymer material containing a predetermined amount of acrylonitrile and styrene and / or conjugated diene, and formed by the acid treatment. The present inventors have found that the polymer material can be modified into a soil modifier by converting the formed acid group and the residual free acid of the acid into a salt.
[0014]
The soil modifier thus obtained has an acid group formed by acid treatment in a polymer material containing acrylonitrile and styrene and / or conjugated diene as described later. Since the residual free acid contains a polymer composed mainly of potassium or ammonium, for example, it exhibits good water absorption even in an aqueous electrolyte solution, and a part of the nitrile group remains. A soil modifier having high gel strength and containing a soil improving component can be obtained without showing water solubility.
[0015]
As a polymer material containing acrylonitrile and styrene and / or conjugated diene, which is a material for the soil modifier of the present invention, 5-80 mol%, preferably 10-60 mol, of acrylonitrile units in the polymer. %, More preferably 20 to 50 mol%. If the content of the acrylonitrile unit is less than this, it becomes water-soluble during acid treatment and is not suitable as a soil modifier. Further, if the content of acrylonitrile units is too large, the polymer material becomes hard and it becomes difficult to pulverize into small pieces, or the content of styrene and / or conjugated diene part in the polymer material is small. Since the introduction rate of the base decreases and the soil improvement effect also decreases.
[0016]
Further, this polymer material contains at least one kind of styrene or conjugated diene (butadiene, isoprene) as a structural unit other than acrylonitrile, 20 to 95 mol%, preferably 40 to 85 mol%, more preferably 50 to 80. It is desirable to contain in the ratio of mol%.
[0017]
These styrene and / or conjugated diene structural units are introduced with hydrophilic groups into the material by the acid treatment of the present invention and subsequent salt formation, for example, salt formation mainly composed of potassium and ammonium. Therefore, it is necessary to improve the hydrophilic water absorption of the resulting soil modifier.
[0018]
In addition, this polymer material may contain another structural unit in the molecule as long as a predetermined amount of the acrylonitrile, styrene, or conjugated diene is introduced.
[0019]
Such other structural units include maleic anhydride, itaconic anhydride, α-methylstyrene, acrylamide, methacrylamide, acrylic acid or acrylic acid ester (saturated or unsaturated hydrocarbon having 1 to 10 carbon atoms), Examples include methacrylic acid or methacrylic acid ester (saturated or unsaturated hydrocarbon having 1 to 10 carbon atoms), vinyl acetate, vinyl chloride, ethylene, propylene, butylene, vinylpyrrolidone, vinylpyridine, and the like.
[0020]
As the molecular weight (Mw) of the polymer material, the weight average molecular weight (Mw) is preferably 1,000 to 20,000,000, and more preferably 10,000 to 1,000,000. preferable. If the molecular weight is lower than this, the acid treatment and subsequent salt formation, for example, formation of salts mainly composed of potassium and ammonium will show water solubility, making it impossible to obtain the desired soil modifier. On the other hand, if the molecular weight is higher than this, the reaction rate at the time of acid treatment and subsequent formation of a salt mainly composed of potassium and ammonium becomes slow, which is not practical.
[0021]
Examples of the polymer material containing acrylonitrile and styrene and / or conjugated diene include ABS (acrylonitrile-butadiene-styrene) resin, SAN (styrene-acrylonitrile) resin, NBR (acrylonitrile-butadiene rubber) resin, ASA. (Acrylate-styrene-acrylonitrile) resin, ACS resin (acrylonitrile-chlorinated polyethylene-styrene resin) and the like are preferable.
[0022]
These polymer materials may be newly manufactured virgin materials, discharged products (half-finished products) in the production process of resin raw materials and molded products, and casings used for electrical products and automobiles. It may also be used waste materials molded for a specific purpose from various component materials, tubes, hoses, and various cushioning materials. The place of discharge may be from a factory, retail store, home, etc., but those collected from the factory, retail store, etc. have a relatively better composition than general waste from the home, etc. It is more desirable because there are many things.
[0023]
The polymer material may be an alloy with another resin, and is a waste material containing additives such as facial dyes, stabilizers, flame retardants, plasticizers, fillers, and other auxiliary agents. Also good. Alternatively, it may be a mixture of used waste material and virgin material.
[0024]
The other resin that can be mixed with the polymer material is preferably a resin that does not inhibit the acid treatment of the present invention and subsequent salt formation, for example, salt formation mainly composed of potassium and ammonium, such as polyphenylene ether. , Polycarbonate, polyphenylene sulfide, polyethylene terephthalate, polybutylene terephthalate, polyamide, polyester and the like. In addition, it is desirable that these resins are mixed to 60% by weight or less with respect to the polymer material. When the content of these resins is increased, acid treatment and subsequent salt formation, for example, salt formation reaction mainly composed of potassium and ammonium are inhibited.
[0025]
Then, the polymer material containing at least one of acrylonitrile and styrene and / or conjugated diene as a constituent unit is subjected to acid treatment, followed by salt formation, for example, a salt mainly composed of potassium or ammonium. By doing so, the soil modifier of the present invention is obtained.
[0026]
In addition, it is desirable to make the said polymeric material into a small piece beforehand, before performing the acid treatment of a 1st step with respect to a polymeric material. Examples of the method of making the polymer material into small pieces include the following.
[0027]
(1) Crushing with a pulverizer → Sieving
When the polymer material contains a rubber component, it is preferable to grind after the freezing treatment.
[0028]
(2) Heat-melt and pelletize into fine beads.
[0029]
The size of the polymer material piece is preferably 3.5 mesh or less. When the size is larger than the above diameter, the surface area of the reactant becomes small and it is difficult to be acid-treated, so the reaction time is not practical and the water absorption of the necessary performance as a soil modifier is greatly reduced. become.
[0030]
Here, if an inorganic pigment (carbon black, titanium oxide, etc.) is contained in the polymer material that is the raw material of the soil modifier, the inorganic pigment is removed from the polymer material during the reaction, and the acid is the same material. It becomes easy to permeate the surface, and the periphery of the inorganic pigment is easily treated with acid, thereby promoting the acid treatment. For this reason, the water absorption effect of the soil modifier is improved.
[0031]
These carbon black and titanium oxide may be originally contained in the polymer material, or may be individually added to and mixed with a soil modifier. This is desirable in improving the performance of soil modifiers that produce water. These carbon black and titanium oxide may be those generally used as plastic colorants, reinforcing agents, and electrical conductivity-imparting materials.
[0032]
Carbon black may be produced by any of the channel method, the furnace method, and the thermal method, and may be used alone and / or in combination. The average particle diameter is 5 to 500 mμ, preferably 10 to 50 mμ.
[0033]
Titanium oxide may be any type of rutile type, anatase type, and ultrafine particle titanium, and each may be used alone and / or in combination. The average particle size is 0.01 to 50 mμ, preferably 0.05 to 10 mμ.
[0034]
The content of the carbon black and titanium oxide contained in the soil modifier is 0.01 to 20% by weight, preferably 0.05 to 10% by weight, based on the dry weight. is there.
[0035]
And as an acid used for the acid treatment with respect to the polymeric material which contains at least 1 or more types of the said acrylonitrile, styrene, and / or conjugated diene as a structural unit, an inorganic acid is suitable. The amount of the inorganic acid charged is 1 to 500 times, preferably 10 to 200 times the weight of the polymer material. If the amount of inorganic acid added is less than this, the rate of introduction of acid groups into styrene and conjugated dienes and the rate of hydrolysis of acrylonitrile groups will be reduced, reducing the water absorption required as a soil modifier. It will be. On the other hand, if the amount of the inorganic acid added is larger than this, it is necessary to treat the excess acid, which is disadvantageous in terms of economy and work.
[0036]
Examples of the inorganic acid include sulfonating agents such as concentrated sulfuric acid, sulfuric anhydride, fuming sulfuric acid, and chlorosulfonic acid, and nitric acid, fuming nitric acid, phosphoric acid, phosphorus chloride, phosphorus oxide, and the like. Among these, concentrated sulfuric acid, sulfuric anhydride, fuming sulfuric acid, and chlorosulfonic acid are preferable, and concentrated sulfuric acid of 70% by weight or more is particularly preferable.
[0037]
These inorganic acids may be used alone or in combination of two or more. When using 2 or more types, you may mix and may add sequentially. For example, after the polymer material is first treated with concentrated sulfuric acid, anhydrous sulfuric acid is added to obtain a water-absorbing shape-stable water absorption. This is because the nitrile portion in the polymer material is mainly hydrolyzed by the treatment with concentrated sulfuric acid, and then the styrene or conjugated diene portion is forcibly sulfonated by treatment with sulfuric anhydride. This is because a soil modifier having a high degree of conversion can be obtained.
[0038]
The acid treatment may be performed in an inorganic acid, but may be performed in a system using an organic solvent. Usable organic solvents are aliphatic halogenated hydrocarbons having 1 to 2 carbon atoms (preferably, for example, 1,2-dichloroethane, chloroform, dichloromethane, 1,1-dichloroethane, etc.), aliphatic cyclic. Hydrocarbon (preferably, for example, cyclohexane, methylcyclohexane, cyclopentane, etc.), nitromethane, nitrobenzene, sulfur dioxide, paraffinic hydrocarbon (carbon number 1 to 7), acetonitrile, carbon disulfide, tetrahydrofuran, 1, 2 -Dimethoxyethane, acetone, methyl ethyl ketone, thiophene and the like. Preferred are aliphatic halogenated hydrocarbons having 1 to 2 carbon atoms, aliphatic cyclic hydrocarbons, nitromethane, nitrobenzene, and sulfur dioxide. These solvents may be used alone or as a mixture of plural kinds. In mixing in the solvent, the mixing ratio is not particularly limited.
[0039]
These organic solvents are preferably less than 200 times the weight of the polymer material. When the addition amount of the organic solvent is larger than this, the reaction rate of the acid treatment is lowered and it is economically disadvantageous.
[0040]
In the acid treatment for the polymer material, a Lewis acid group may be used as necessary. Examples of Lewis acid groups include alkyl phosphates (triethyl phosphate, trimethyl phosphate), dioxane, acetic anhydride, ethyl acetate, ethyl palmitate, diethyl ether, thioxan, and the like.
[0041]
The inorganic acid or organic solvent once used for the acid treatment may be recovered after completion of the reaction and may be recovered as it is, or may be recovered by a method such as extraction or distillation and used again for the reaction.
[0042]
Thus, by performing the acid treatment as described above on the polymer material, an acid group is introduced into the styrene and / or conjugated diene unit in the polymer material, while the acrylonitrile unit is hydrolyzed. It is amidated and modified to a hydrophilic resin. Acid groups introduced into the styrene or conjugated diene unit by the acid treatment include sulfonic acid and -PO (OH).₂, -CH₂PO (OH)₂Etc.
[0043]
When a sulfonic acid group is introduced as the acid group, the polymer material can be reacted with a sulfonating agent such as concentrated sulfuric acid, sulfuric anhydride, fuming sulfuric acid or chlorosulfonic acid as it is or in a solvent. . -PO (OH)₂The introduction of the group is made possible by adding phosphorus trioxide in a solvent and further hydrolyzing. Of these acid groups, sulfonic acid groups are preferred. These acid groups may be used alone or two or more of them may be introduced into the polymer material.
[0044]
However, in order to satisfy the properties as a soil modifier, the amount of the acid group contained in the polymer material is 5 to 95 mol%, preferably 10 to 70 mol%, based on all units. is there. If the amount of acid groups increases, the acid-treated product of the polymer material becomes water-soluble and cannot be used as a soil modifier. On the other hand, if the amount of acid groups is lower than this, water permeability and water absorption (especially with respect to the aqueous electrolyte solution) will be reduced, and subsequent salt formation, for example, potassium or ammonium ion exchange treatment will not proceed, and effective soil modification will not occur. Not a quality agent.
[0045]
By performing the acid treatment under the following conditions, a predetermined amount of ionic groups can be introduced into the polymer material.
[0046]
The reaction temperature of the acid treatment varies greatly depending on whether or not an organic solvent is used, but is generally 0 to 200 ° C., and a preferable reaction temperature is 30 to 120 ° C. If the reaction temperature is too low, the reaction rate becomes slow and impractical, and it has good performance but no soil modifier can be obtained. On the other hand, if the reaction temperature is too high, the molecular chain of the polymer material is easily cleaved due to thermal decomposition and dissolves in water.
[0047]
The reaction time varies greatly depending on the reaction temperature, but is generally about 1 minute to 40 hours, preferably 5 minutes to 2 hours. If the reaction time is too short, the reaction does not proceed sufficiently. Moreover, when reaction time is too long, production efficiency will worsen.
[0048]
Then, the acid group introduced into the polymer material by the acid treatment and the residual free acid of the acid as described above are neutralized with a cation mainly composed of potassium or ammonium to form a salt. The intended soil conditioner of the present invention is obtained. Here, the residual free acid is an acid used for acid treatment of the polymer material to introduce acid groups into the polymer material, and the residual acid after the acid treatment reaction. That is.
[0049]
As a method of forming a salt in the acid group of the acid treatment and the residual free acid of the acid, the reaction product in the acid treatment is first filtered with a filter or the like, washed with a large amount of water, and then basic. It can be performed by a method of adding a substance or a salt thereof, a method of adding the reaction product liquid system as it is to an aqueous solution of a basic substance or a salt thereof, and the like.
[0050]
The basic substance or salt thereof used in the salt formation reaction includes ammonium, oxides of alkali metals (sodium, lithium, potassium, etc.) and alkaline earth metals (magnesium, calcium, etc.), hydroxides, carbonates. Examples include salts, acetates, sulfates, phosphates and the like.
[0051]
The amount of residual free acid salt contained in the soil modifier is 0.01% by weight or more, preferably 0.1% by weight or more of the dry weight of the polymer material in which the formed acid groups are converted into salts. It is. If the residual free acid salt content is too low, the osmotic pressure based on the ionic concentration of the soil will be superior, which may reduce the ionic concentration of the soil and destroy the ionic balance of the soil. May interfere.
[0052]
As described above, the reaction product obtained by the salt formation reaction is in the form of a gel, and thereafter, the desired soil modifier is obtained by drying such as sun, heating, decompression, centrifugation, and pressing. Can do.
[0053]
By the treatment method shown above, a polymer body in which an acid group is formed in the polymer material by being treated with a nitrile group, a hydrolyzate, and an acid, and the acid group is converted into a salt; A soil modifier containing the residual free acid salt of the acid can be obtained. This soil modifier has an unreacted nitrile group, so that water-insolubility and improved gel strength can be obtained. In addition, the hydrolyzate of the same nitrile group and the acid group that has become a salt increase water absorption, gelling with respect to water, and further, the salt component of the residual free acid salt acts on the soil. The soil improvement effect is obtained.
[0054]
【Example】
Here, although the samples of Examples 1 to 4 and Comparative Example 1 were actually prepared and evaluated as soil modifiers according to the present invention, the present invention is not limited thereto.
[0055]
<Example 1>
To 30 parts by weight of concentrated sulfuric acid (96% by weight), add 1 part by weight of ABS (acrylonitrile-butadiene-styrene) resin waste material crushed and classified to 16-32 mesh with a freezing shredder, and react at 80 ° C. for 20 minutes. I let you. This ABS resin waste material is a black part of an 8 mm cassette tape guard panel, which is composed of 52 mol% of styrene, 28 mol% of acrylonitrile, 20 mol% of butadiene, and 2 carbon black. It is contained by weight.
[0056]
After completion of the reaction, the solid matter in the system is filtered through a glass filter, washed with water, neutralized with 50 parts by weight of 1N sodium hydroxide solution, and further washed with sufficient water. When it became the following, it took out and dried at 105 degreeC with the circulating air dryer for 2 hours. By this operation, a black solid was obtained.
[0057]
This solid was immersed in 2000 parts by weight of pure water with respect to 1 part by weight of the solid, sufficiently swollen, stirred for 36 hours with occasional stirring, and the supernatant was analyzed. The free amount of sodium sulfate was 1.2% by weight of the solid.
[0058]
From the result of elemental analysis of the solid sulfur and the result of the elution amount, it was confirmed that the sulfonic acid group in the solid was 33 mol% in all monomer units. The content of sodium was approximately equimolar in terms of sulfonic acid groups.
[0059]
<Example 2>
In concentrated sulfuric acid (96% by weight), 1 part by weight of SAN (styrene-acrylonitrile) resin waste material crushed and classified to 16 to 32 mesh by a freezing shredder was added and reacted at 80 ° C. for 20 minutes. This SAN resin waste material is a transparent part of an 8 mm cassette tape guard panel, and is composed of 60 mol% of styrene and 40 mol% of acrylonitrile.
[0060]
After completion of the reaction, the solid matter in the system is filtered through a glass filter, washed with water, neutralized with 30 parts by weight of concentrated aqueous ammonia, sufficiently filtered, and dried at 100 ° C. for 3 hours in a circulating air dryer. It was. By this operation, a brown solid was obtained. The amount of liberated ammonium sulfate analyzed by the same method as in Example 1 for this solid was 2.6% by weight of the solid.
[0061]
Moreover, the sulfonic acid group in the solid was 36 mol% in the total monomer units. Ammoniumation is considered to be approximately equimolar.
[0062]
<Example 3>
In 90 parts by weight of concentrated sulfuric acid (96% by weight), 3.5 parts by weight of the ABS resin waste material pulverized and classified to 16 to 32 mesh with a freezing shredder was added and reacted at 60 ° C. for 60 minutes. Then, fuming sulfuric acid (SO_Three: 0.5% by weight) was added, and the reaction was further carried out for 30 minutes. This ABS resin waste material is a white part of a personal computer casing, which is composed of 46 mol% of styrene, 39 mol% of acrylonitrile, 13 mol% of butadiene, and further contains 1 wt% of titanium oxide. To do.
[0063]
After completion of the reaction, the solid matter in the system is filtered, washed with water, neutralized with 30 parts by weight of concentrated aqueous ammonia, filtered, and 10 parts by weight of 1N aqueous potassium hydroxide solution is poured into it, followed by washing with water. And filtered. This was dried in a dryer for 2 hours. A solid was obtained by this operation. The amount of released ammonium sulfate analyzed for the solid in the same manner as in Example 1 was 1.9% by weight of the solid, and the amount of released potassium sulfate was 0.9% by weight of the solid. It was.
[0064]
Moreover, the sulfonic acid group in the solid was 42 mol% in all monomer units. The potassium content was 0.35 relative to the sulfonic acid group. The balance is considered to be ammoniumated.
[0065]
<Example 4>
To 70 parts by weight of cyclohexane, 3 parts by weight of the ABS resin waste material used in Example 1 was added, and 4.2 parts by weight of sulfuric anhydride was added dropwise while maintaining the temperature at 30 ° C. Thereafter, the reaction was carried out for 2 hours while maintaining the temperature at 30 ± 2 ° C.
[0066]
After completion of the reaction, the solid matter in the system was filtered, washed with water and then dried. This was neutralized with 30 parts by weight of concentrated aqueous ammonia and filtered, and 10 parts by weight of a 1N aqueous potassium hydroxide solution was poured into the solution, followed by washing with water. This was dried in a dryer for 2 hours to obtain a solid. The amount of released ammonium sulfate analyzed for the solid in the same manner as in Example 1 was 1.1% by weight of the solid, and the amount of released potassium sulfate was 0.8% by weight of the solid. It was.
[0067]
Moreover, the sulfonic acid group in the solid was 25 mol% in the total monomer units. The potassium content was 0.42 with respect to the sulfonic acid group. The balance is considered to be ammoniumated.
[0068]
<Comparative example 1>
The black solid obtained in Example 1 was immersed in 2000 parts by weight of pure water with respect to 1 part by weight of the solid, sufficiently swollen, allowed to stand for 36 hours with occasional stirring, and filtered. Further, pure water was added thereto to make 2000 parts by weight, and the mixture was left to stir twice in the same manner, and the supernatant was analyzed. The free amount of sodium sulfate was 90 ppm of the solid. This was dried in a dryer for 2 hours.
[0069]
The performance of the solid materials of Examples 1 to 4 and Comparative Example 1 obtained as described above as soil modifiers was evaluated.
[0070]
The performance evaluation of the obtained solid as a soil modifier was performed by planting five leaf seedlings of eggplant (Solanum mclongcna L.) in the soil of the Kanto Loam Formation in Yokohama City.
[0071]
1 part by weight of the solid matter obtained in Examples 1 to 4 was mixed with 100 parts by weight of the soil of the Kanto Loam layer to obtain mixed soil. This mixed soil was filled with about 2 cm at the root of the seedling, and the average leaf number of the eggplant in early May and early June was examined.
[0072]
Table 1 shows the average number of leaves of the eggplant in the beginning of May and the beginning of June in the soil mixed with the solid matter obtained in Examples 1 to 4 and Comparative Example 1. Moreover, what filled up the solid non-mixed soil similarly was shown in Table 1 as the comparative example 2.
[0073]
[Table 1]

[0074]
As is apparent from Table 1, the average number of eggplant leaves in early June in the soil mixed with the solid matter obtained in Examples 1 to 4 is Comparative Example 1 and Comparative Example 2. It can be seen that the number is larger than in the case of. This is considered because the solid substance mixed in the soil has a function of retaining moisture and promotes the growth of eggplant. In particular, the effect is good when the amount of residual free acid salt is 0.01% by weight or more based on the solid.
[0075]
Accordingly, a polymer material containing acrylonitrile and styrene or conjugated diene as a constituent unit is subjected to an acid treatment, followed by salt formation, and a residual free acid of the acid is obtained. It was found that the mixture with salt showed excellent performance as a soil modifier.
[0076]
【The invention's effect】
In the present invention, a soil modifier that promotes plant growth can be obtained. Since this soil modifier can be manufactured from the used waste plastic material, it leads to the effective use of resources and can contribute to the global environmental conservation.

Claims (10)

A polymer material containing acrylonitrile and styrene and / or conjugated diene as a constituent unit is treated with an acid, whereby an acid group is formed in the polymer material, and the acid group is converted into a salt. Molecular bodies,
A residual free acid salt of the above acid,
The acid group is a sulfonic acid group, and the salt is a sodium salt, an ammonium salt, or a potassium salt,
The acid group is 25 mol% or more and 42 mol% or less with respect to all units of the polymer.
The soil modifying agent, wherein the residual free acid salt is contained in a proportion of 1.2% by weight or more and 1.9% by weight or less based on the polymer . The polymeric material, acrylonitrile - butadiene - styrene resin, styrene - acrylonitrile resin, acrylonitrile - soil modifying agent 請 Motomeko 1, wherein you contain at least one or more of butadiene rubber. The polymeric material, soil modifying agent 請 Motomeko 1 wherein ing from the spent resin. The polymeric material, soil amendment according to any one of claims 1 to 3 that contain an inorganic pigment. The inorganic pigment, soil modifying agent 請 Motomeko 4 wherein Ru carbon black or titanium oxide der. An acid treatment step in which a polymer material containing acrylonitrile and styrene and / or conjugated diene as a constituent unit is treated with an acid to form an acid group;
A chlorination treatment step for salting the acid groups formed in the polymer material in the acid treatment step and the residual free acid of the acid,
The acid group is a sulfonic acid group, and the salt is a sodium salt, an ammonium salt, or a potassium salt,
In the acid treatment step, the acid group is introduced in an amount of 25 mol% or more and 42 mol% or less with respect to all units of the polymer.
The method for producing a soil modifier , wherein a salt of the residual free acid is contained in a proportion of 1.2% by weight or more and 1.9% by weight or less with respect to the polymer . In the acid treatment step, the polymer material is an acrylonitrile - butadiene - styrene resin, styrene - acrylonitrile resin, acrylonitrile - method of manufacturing a soil modifying agent 請 Motomeko 6 wherein you contain at least one or more of butadiene rubber . In the acid treatment step, the polymer material, method of manufacturing a soil amendment in the name Ru請 Motomeko 6 wherein the spent resin. In the acid treatment step, the polymer material, method of manufacturing a soil amendment according to any one of claims 6 to 8 that contain an inorganic pigment. The inorganic pigment is carbon black or Ru oxide titanium der 請 Motomeko 9 manufacturing method of soil amendment according.