JPH07258338A - Solid fuel slurry and dispersant thereof - Google Patents

Abstract

PURPOSE:To obtain a dispersant which provides a solid fuel slurry excellent in storage stability, vibration stability, etc., by incorporating at least a specified amt. of a sulfonation product obtd. by sulfonating a specific star (co)polymer into the dispersant. CONSTITUTION:At least one monomer selected from the group consisting of an aliph. diene (e.g. 1,3-butadiene) and an arom. vinyl monomer (e.g. styrene) is subjected to anionic polymn., if necessary together with other coplymerizable monomers (e.g. methyl acrylate). The resultant living polymer is coupled with a coupling agent (e.g. dimethyl adipate) without stopping the polymn. to provide a star (co)polymer having the average number of branching of 2.3 or higher. The (co)polymer is sulfonated, and a dispersant for a solid fuel oil contg. the sulfonation product (or its salt) in an amt. of 10wt.% or higher is produced. The dispersant is incorporated in an amt. of 0.01-5wt.% into a solid fuel oil.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a solid fuel slurry containing a specific additive and a dispersant therefor.

[0002]

2. Description of the Related Art Conventionally, an energy structure mainly composed of petroleum has been taken, but in recent years, solid fuels such as coal, petroleum coke, and pitch have been re-recognized due to the exhaustion of petroleum resources, and various uses thereof have been studied. Has been done. However,
Since these solid fuels are solid unlike liquid fuels such as petroleum, it is difficult to transport them by ordinary pipelines or tank trucks. For this reason, various technologies have been proposed in which a solid fuel such as coal is pulverized, dispersed in water and treated as a slurry in the same manner as a liquid. In this case, a slurry having a low solid fuel concentration and a large amount of water can be used to obtain a slurry having a low viscosity, but this is not a good measure in terms of fuel efficiency. Further, the slurry thus obtained has a drawback that the solid fuel will settle when left to stand.

As a method of increasing the solid fuel concentration and improving the stability of the slurry, a means of adding various dispersants to the slurry to enhance the dispersibility of the solid fuel in water has been proposed. For example, as a dispersant for a solid fuel slurry, an aliphatic diene (co) polymer sulfonate (Japanese Patent Laid-Open No. 2-227).
404) or polystyrene sulfonic acid (JP-A-62-62)
-590) and the like are known. The solid fuel slurry to which this kind of dispersant is added has improved fluidity and stability as compared with the case where it is not added, but it cannot be said to have reached a sufficiently satisfactory level.

[0004]

SUMMARY OF THE INVENTION The present invention has been made on the basis of these conventional technical problems, and has a high fluidity even at a high concentration even though the required amount of a dispersant is small. Moreover, it is an object of the present invention to provide a dispersant for solid fuel slurries, which can maintain long-term storage stability and is also excellent in vibration stability during shipping.

[0005]

DISCLOSURE OF THE INVENTION The present invention is a star-shaped compound having at least one constitutional unit selected from an aliphatic diene and an aromatic vinyl monomer and having a branch number of 2.3 or more on average. (EN) Dispersant for solid fuel slurry, characterized by containing 10% by weight or more of a sulfonated compound (salt) obtained by sulfonation of a polymer, and a solid fuel slurry containing the dispersant. To do.

The solid fuel slurry dispersant of the present invention is a sulfonated compound (salt) obtained by sulfonation of a star-shaped (co) polymer, for example, at least an aliphatic diene and an aromatic vinyl monomer. If necessary, anionic polymerization of one monomer as an essential component and another monomer copolymerizable therewith is performed, and then the resulting living polymer is subjected to a coupling reaction with a coupling agent without stopping the polymerization. To form a (co) polymer containing a star-shaped polymer which is a branched polymer, and then sulfone.

The number of branches of the branched polymer constituting the sulfonate (salt) used in the dispersant for solid fuel slurry of the present invention is 2.3 or more on average, preferably 2.5 or more, and more preferably. It is 2.5 to 20, and if it is less than 2.3, the effect of improving the fluidity or stability of the slurry is small and the object of the present invention cannot be achieved.

Here, the aliphatic diene is a hydrocarbon having 4 to 7 carbon atoms and containing two double bonds in the molecule,
Examples of the aliphatic diene include 1,3-butadiene, 1,2-butadiene, 1,2-pentadiene, 1,
3-pentadiene, 2,3-pentadiene, isoprene, 1,2-hexadiene, 1,3-hexadiene,
1,4-hexadiene, 1,5-hexadiene, 2,3
-Hexadiene, 2,4-hexadiene, 2,3-dimethyl-1,3-butadiene, 2-ethyl-1,3-butadiene, 1,2-heptadiene, 1,3-heptadiene, 1,4-heptadiene, 1 , 5-heptadiene,
1,6-heptadiene, 2,3-heptadiene, 2,5
In addition to heptadiene, 3,4-heptadiene, 3,5-heptadiene and the like, various branched dienes having 4 to 7 carbon atoms can be mentioned, preferably 1,3-butadiene, isoprene, 1,3-pentadiene, and Preferred is isoprene. These aliphatic dienes can be used alone or in combination.
One or more species can be used in combination. As the aromatic vinyl monomer, styrene, α-methylstyrene, vinyltoluene, p-methylstyrene, vinylnaphthalene,
Examples thereof include vinyl biphenyl, and preferably styrene. Specific preferred examples of star (co) polymers using these monomers are polybutadiene, polyisoprene, polystyrene, butadiene-styrene copolymer, isoprene-styrene copolymer, isoprene-butadiene copolymer, and the like. And particularly preferred specific examples thereof include polyisoprene and isoprene-styrene copolymer.

In the present invention, the above-mentioned aliphatic diene or aromatic vinyl monomer may be used in combination with other copolymerizable monomer (hereinafter also referred to as "other monomer"). Other monomers include methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, and 2
-Alkyl esters of acrylic acid or methacrylic acid such as hydroxyethyl (meth) acrylate, and general formula

[0010]

[Chemical 1]

(Wherein R, R'and R "are the same or different and represent a hydrogen atom or an alkyl group having 1 to 6 carbon atoms or an aryl group having 6 to 10 carbon atoms) Anhydrides of mono- or dicarboxylic acids or dicarboxylic acids such as acrylic acid, methacrylic acid, crotonic acid, maleic acid, fumaric acid, itaconic acid; vinyl cyanide compounds such as acrylonitrile and methacrylonitrile; vinyl chloride, vinylidene chloride, vinyl methyl ethyl ketone , Vinyl methyl ether, vinyl acetate, vinyl formate, allyl acetate, methallyl acetate,
Unsaturated group-containing compounds such as acrylamide, methacrylamide, N-methylolacrylamide, glycidyl acrylate, glycidyl methacrylate, acrolein and allyl alcohol; ethylene oxide, propylene oxide, tetrahydrofuran, 2-methyltetrahydrofuran, styrene oxide, butylene oxide, glycidyl ether. Cyclic ether compounds such as; Cyclic thioethers such as ethylene sulfide and propylene sulfide,
Examples thereof include cyclic esters such as propiolactone and ε-caprolactam, and nitrogen-containing compounds such as vinylpyridine. Among these other monomers, ethylene oxide and propylene oxide are preferable. These other monomers may be used alone or in combination of two or more.

When these other monomers are used in combination,
The amount of aliphatic diene or aromatic vinyl compound used is
50% by weight or more, preferably 70% by weight or more, more preferably 80 to 98% by weight, and if less than 50% by weight, a sulfonated product (salt) obtained by sulfonation is used as a dispersant for a solid fuel slurry. Moreover, the fluidity and stability of the slurry do not reach a sufficient level.

The (co) polymer used in the sulfonated compound (salt) is a polymer obtained by (co) polymerizing at least one monomer selected from the above-mentioned aliphatic diene or aromatic vinyl monomer. , Or a block type or a random type obtained by copolymerizing at least one monomer selected from the above-mentioned aliphatic diene or aromatic vinyl monomer and another monomer when other monomers are used in combination. It is a (co) polymer containing a branched, preferably star-shaped polymer obtained by coupling a type copolymer.

The method for producing this (co) polymer is as follows. For example, the above (co) polymer is subjected to anionic (co) polymerization with an aliphatic diene or an aromatic vinyl monomer or another monomer by using an anionic polymerization initiator in a hydrocarbon solvent, followed by polymerization. Without stopping
The resulting living polymer is subjected to a coupling reaction with a coupling agent to obtain a (co) polymer containing a branched star polymer.

The hydrocarbon solvent used for the polymerization is at least one selected from the group consisting of aromatic hydrocarbons, paraffins, cycloparaffins and ethers.
Suitable solvents of the species include n-pentane, n-hexane, cyclohexane, n-heptane, octane, benzene, toluene, xylene, ethylbenzene, naphthalene, diethyl ether, tetrahydrofuran, diglyme and the like.

Examples of the anionic polymerization initiator include alkali metals, organic alkali metals, organic alkaline earth metals and the like. Of these, lithium metal, sodium metal, potassium metal and the like are used as the alkali metal, and methyllithium, ethyllithium, n-butyllithium, sec-butyllithium, amyllithium, hexyllithium, 2-ethylhexyllithium are used as the organic alkali metal. Phenyl lithium, tolyl lithium, xylyl lithium, naphthyl lithium, dilithium naphthalene, methyl sodium, ethyl sodium, n-butyl sodium, amyl sodium, naphthyl sodium,
Examples thereof include disodium naphthalene, methyl potassium, ethyl potassium, n-butyl potassium, amyl potassium, naphthyl potassium and dipotassium naphthalene. Examples of the organic alkaline earth metal include methyl magnesium bromide, ethyl magnesium chloride, butyl magnesium chloride, diethyl magnesium, diethyl zinc and the like.

Among these anionic polymerization initiators,
Preferred are lithium metal, sodium metal, potassium metal, methyllithium, n-butyllithium, sec-butyllithium, and amyllithium. Particularly, n-butyllithium and sec-butyllithium are preferable. The amount of these anionic polymerization initiators is 0.0 per 100 parts by weight of the monomer.
Used in an amount of 4 to 3.0 parts by weight.

During polymerization, it is possible to add a compound such as ethers or amines to improve the efficiency of the initiator and control the stereoregularity and microstructure of the polymer produced. Specific examples of these compounds include ethers such as diethyl ether, tetrahydrofuran, propyl ether, butyl ether, higher ethers, and ether derivatives of polyethylene glycol such as ethylene glycol dibutyl ether, diethylene glycol dimethyl ether, diethylene glycol dibutyl ether, and triethylene glycol dimethyl ether. Etc. Also, as amines, tertiary amines such as tetramethylethylenediamine, pyridine, tributylamine, etc.
Examples thereof include primary amines, which are used together with the above hydrocarbon solvent.

Further, the polymerization reaction is usually conducted at -100 ° C to
Within the range of + 150 ° C, it is determined by the types of the polymerization initiator and the monomer. Further, the polymerization may be carried out while controlling at a constant temperature, or may be carried out at an elevated temperature without heat removal. Polymerization may be carried out while successively adding various monomers.

A (co) polymer containing a branched star polymer can be obtained by adding a coupling agent to the polymerization system and coupling the living polymer without stopping the polymerization. . Examples of this coupling agent include chloroform, carbon tetrachloride, bromoform,
Carbon tetrabromide, polyhalides such as tin tetrachloride, silicon tetrachloride, 1,2-bis (triclosyl) ethane, 1,2
-Silicon compounds such as bis (trichloromethylsilyl) ethane, methyltrichlorosilane, octachlorosilane and dodecachlorosilane, 1,2,4-trichloromethylbenzene, 1,2,4,5-tetrachloromethylbenzene, hexa-p- (Chloromethyl) phenylbenzene,
Aromatic halides such as 1,3,5-tribromomethylbenzene, aromatic divinyl compounds such as p-divinylbenzene and m-divinylbenzene, dimethyl adipate, diethyl adipate, dimethyl terephthalate, trimethyl citrate, etc. Examples thereof include ester compounds, acid anhydrides such as maleic anhydride and itaconic anhydride, and isocyanate compounds such as tolylene diisocyanate, tolidine diisocyanate, and methylenebis (4-phenylisocyanate). Among these coupling agents, m, p-divinylbenzene, dimethyl adipate, diethyl adipate, maleic anhydride, itaconic anhydride, tolylene diisocyanate, methylenebis (4-
Phenyl isocyanate) is particularly preferred.

The amount of the coupling agent used is 0.01 to 30 mol, preferably 0.05 to 20 mol, per 1 mol of the polymerization initiator. If it is less than 0.01 mol,
The content of the star-shaped polymer having an average number of branches of 2.3 or more may be less than 10% by weight, while if it exceeds 30 mol,
Insoluble matter may form after sulfonation.

The thus obtained (co) polymer contains a star polymer having a polymer structure in which a living polymer is bound in a star shape via a coupling agent and radially extends. The content of the star polymer in the (co) polymer is 10% by weight or more, preferably 15% by weight or more, more preferably 15 to 95% by weight, and if less than 10% by weight, the fluidity of the slurry or The effect of improving stability is not sufficiently exerted, and the object of the present invention cannot be achieved. The average number of branches of the (co) polymer is 2.3 as described above.
Or more, preferably 2.5 or more, more preferably 2.5
~ 20.

The molecular weight of the star polymer thus obtained depends on the reaction conditions, in particular the type and amount of the polymerization initiator,
Further, it can be appropriately changed depending on the kind and amount of the solvent or the reaction temperature and the reaction time, but the polystyrene-equivalent weight average molecular weight is 450 to 5,000,000.
It is 0, preferably 1,000 to 2,500,000, and more preferably 2,500 to 1,000,000.
When it is less than 450, the effect of improving the fluidity or stability of the slurry is not sufficiently exerted, and the effect of the present invention is small, while when it exceeds 5,000,000, gelation is caused or the obtained sulfonate (salt) is Poor water solubility.

This (co) polymer is prepared by using a known sulfonating agent such as sulfuric anhydride, fuming sulfuric acid, chlorosulfonic acid, sulfuric acid or sodium hydrogen sulfite for the double bond portion of the (co) polymer. It can be sulfonated under known conditions. During this sulfonation, the double bond is opened to form a single bond, or the hydrogen atom is replaced with a sulfonic acid (salt) while the double bond remains.

As the sulfonating agent in this case, sulfuric acid alone is preferably used, and more preferably, a complex of sulfuric anhydride and an electron donating compound is used. Here, as the electron donating compound, ethers such as N, N-dimethylformamide, dioxane, dibutyl ether, tetrahydrofuran and diethyl ether; amines such as pyridine, piperazine, trimethylamine, triethylamine and tributylamine; dimethyl sulfide and diethyl Examples thereof include sulfides such as sulfides; nitrile compounds such as acetonitrile, ethyl nitrile and propyl nitrile; phosphorus compounds such as triethyl phosphite and tributyl phosphite. Of these, N, N-dimethylformamide and dioxane are preferable.

The amount of the sulfonating agent is usually 0.1 to 10 mol, preferably 0.3 to 10 mol, in terms of anhydrous sulfuric acid, based on 1 mol of the aliphatic diene unit in the aliphatic diene (co) polymer. If the amount is less than 0.1 mol, the reaction yield is low, while if it exceeds 10 mol, the amount of unreacted anhydrous sulfuric acid increases, and after neutralization with an alkali, a large amount of sulfate is generated, resulting in a decrease in purity. Therefore, it is not preferable. In this sulfonation, a solvent inert to sulfuric acid which is a sulfonating agent may be used, and examples of the solvent include halogenated hydrocarbons such as chloroform, dichloroethane, tetrachloroethane, tetrachloroethylene and dichloromethane; nitromethane. , Nitro compounds such as nitrobenzene; liquid sulfur dioxide, propane, butane, pentane,
Examples include aliphatic hydrocarbons such as hexane and cyclohexane. These solvents can be used as a mixture of two or more kinds as appropriate.

The reaction temperature for this sulfonation is usually -7.
0 to + 200 ° C, preferably -30 to + 50 ° C,
If the temperature is lower than -70 ° C, the sulfonation reaction becomes slow, which is not economical. On the other hand, if the temperature exceeds + 200 ° C, a side reaction may occur to blacken or insolubilize the product, which is not preferable.

Thus, an intermediate [sulfonic acid ester of an aliphatic diene (co) polymer, hereinafter referred to as "intermediate"] in which sulfuric anhydride is bonded to the (co) polymer is produced. In the sulfonated compound (salt) of the present invention, water or a basic compound is allowed to act on this intermediate to open the double bond to form a single bond in which a sulfonic acid (salt) is bonded, or a double bond. The bond remains and is obtained by replacing the hydrogen atom with a sulfonic acid (salt).

Examples of the basic compound include hydroxides of alkali metals or alkaline earth metals such as sodium hydroxide, potassium hydroxide, lithium hydroxide, calcium hydroxide, magnesium hydroxide and zinc hydroxide; sodium methoxide. Alkali metal alkoxides such as sodium ethoxide, potassium methoxide, sodium t-butoxide and potassium t-butoxide; carbonates such as sodium carbonate, potassium carbonate, lithium carbonate, calcium carbonate, magnesium carbonate; calcium carbonate, magnesium oxide. Oxides such as; methyllithium, ethyllithium, n-butyllithium, sec-butyllithium,
Organometallic compounds such as amyl lithium, propyl sodium, methyl magnesium chloride, ethyl magnesium bromide, propyl magnesium iodide, diethyl magnesium, diethyl zinc, triethyl aluminum, triisobutyl aluminum; ammonia water, trimethylamine, triethylamine, tripropylamine, tributylamine , Amines such as pyridine, aniline and piperazine; and metal compounds such as sodium, lithium, potassium, calcium and zinc. Among these basic compounds, alkali metal hydroxides, alkaline earth metal hydroxides, and ammonia water are preferable, and sodium hydroxide, calcium hydroxide, calcium carbonate, and ammonia water are particularly preferable. These basic compounds may be used alone or in combination with each other.
It is also possible to use two or more species together.

The amount of the basic compound used is usually 0.1 to 3 mol, preferably 0.5 to 3 mol, per 1 mol of the aliphatic diene unit in the aliphatic diene (co) polymer. However, if it is less than 0.1 mol, the ring-opening reaction of the intermediate (sulfonic acid ester) is not promoted, while if it exceeds 10 mol, the amount of unreacted alkali is large and the purity of the product is lowered, which is not preferable. During the reaction of this intermediate with the basic compound,
It is also possible to use the basic compound in the form of an aqueous solution,
Alternatively, it can be used by dissolving it in an organic solvent inert to the basic compound.

As the organic solvent, in addition to the above various solvents, aromatic hydrocarbon compounds such as benzene, toluene and xylene; methanol, ethanol, propanol,
Examples include alcohols such as isopropanol and ethylene glycol. These organic solvents are appropriately used in 2
A mixture of two or more species can be used. When the basic compound is used as an aqueous solution or an organic solvent solution, the concentration of the basic compound is usually 1 to 70% by weight, preferably 10 to 50% by weight. Also, this reaction temperature is
Usually, -30 to + 150 ° C, preferably -10 to +12
It is carried out at 0 ° C., more preferably 0 to + 100 ° C., and can be carried out under normal pressure, reduced pressure or elevated pressure. Furthermore, this reaction time is usually 0.1 to 24 hours, preferably 0.5 to 5 hours.

The cation species of the sulfonated product (salt) thus obtained are not particularly limited, but in order to make them water-soluble, hydrogen, alkali metal, alkaline earth metal, ammonium, amine Are preferred.
Examples of the alkali metal include sodium and potassium, and examples of the amine include alkylamine such as methylamine, ethylamine, propylamine, dimethylamine, diethylamine, triethylamine, butylamine dibutylamine and tributylamine, ethylenediamine, diethylenetriamine and triethylenetetramine. Examples thereof include polyamine, morpholine and piperidine, and examples of the alkaline earth metal include calcium and magnesium. Also, these cationic species can be exchanged with other cationic species by various ion exchange techniques.

The amount of sulfonic acid (salt) of the above sulfonated compound (salt) is 0.7 to 6 meq / g, preferably 2.5 to 6 meq / g, more preferably 3.0 to 6 m.
If it is less than 0.7 meq / g, the solubility of the sulfonated compound (salt) in water is poor and the slurry performance is not sufficiently exhibited. On the other hand, it is structurally difficult to obtain a sulfonated compound (salt) exceeding 6 meq / g. In addition, gel permeation chromatography (G
The weight average molecular weight in terms of sodium polystyrene sulfonate measured by PC) is usually 1,000 to 10,000.
0,000, preferably 3,000 to 5,000,0
00.

The structure of the sulfonated compound (salt) used in the present invention can be confirmed from the absorption of the sulfonic group by infrared absorption spectrum.
It can be known by acid / alkali titration such as conductivity. The structure can be confirmed by the nuclear magnetic resonance spectrum. Further, the content of the star-shaped (co) polymer in the sulfonated compound (salt) can be determined by the area ratio of GPC. Further, the number of branches of the star-shaped (co) polymer can be calculated from the value obtained by dividing the weight average molecular weight of the polymer after branching by the weight average molecular weight of the polymer before branching.

Further, the polymer structure of the sulfonic acid group-containing star (co) polymer of the present invention has, for example, a star structure represented by the following general formula (I). (P) m−Y (I) [In the general formula (I), P represents a sulfonated product of a (co) polymer constituting a living polymer, m is the number of branches, and Y is a coupling. It shows the agent residue and exerts the same effect whether it is sulfonated or not. ]

In the dispersant for solid fuel slurry of the present invention, the content of the sulfonated compound (salt) of the branched polymer is 1
0% by weight or more, preferably 15 to 95% by weight, 1
If it is less than 0% by weight, the fluidity or stability of the slurry is insufficient.

The dispersant of the present invention is used as a dispersant for a solid fuel slurry. The dispersant of the present invention is usually added to the solid fuel slurry in an amount of 0.01 to 5% by weight, preferably 0.02 to 2% by weight from the viewpoint of workability and economy, and more preferably 0.05. ~ 1% by weight. 0.
If it is less than 01% by weight, the viscosity of the slurry is increased and fluidity is lost, while if it exceeds 5% by weight, economical efficiency is deteriorated, which is a problem.

The dispersant of the present invention is sufficiently effective when used alone in a solid fuel slurry, but the slurry performance may be further improved by using other dispersants or additives in combination. . As the other water-soluble polymer, for example, at least one water-soluble polymer selected from the following components (A) to (G) can be mentioned. (A) A polymer containing a naphthalenesulfonic acid (salt) structural unit, for example, an aldehyde condensate of naphthalenesulfonic acid (salt), polyvinylnaphthalenesulfonic acid (salt), and the like.

(B) Polymers containing ligninsulfonic acid (salt) structural units and derivatives thereof. (C) Styrene sulfonic acid (salt) A polymer containing a structural unit, for example, polystyrene sulfonic acid (salt), styrene-
Styrene sulfonic acid (salt) copolymer etc. (D) Polymers containing norbornene sulfonic acid (salt) structural units, such as 5-propenyl-norbornene-2, dicyclopentadiene, 5-ethylidene-norbornene-2.
(Co) polymers of sulfonated norbornene derivatives such as.

(E) A (co) polymer containing at least one structural unit selected from the group consisting of carboxylic acid (salt) structural units, sulfonic acid (salt) structural units and polyalkylene glycol structural units. Examples of the component include (meth) acrylic acid, maleic acid, fumaric acid, and itaconic acid. Examples of the component include sulfoalkyl (meth) acrylates such as styrene sulfonic acid, isoprene sulfonic acid, butadiene sulfonic acid, 2-sulfoethyl (meth) acrylate, and 3-sulfopropyl (meth) acrylate. As components, polyalkylene glycol mono (meth) acrylates such as polyethylene glycol mono (meth) acrylate, polyethylene glycol-polypropylene glycol mono (meth) acrylate, methoxy polypropylene glycol (meth) acrylate, ethoxy polypropylene glycol (meth) acrylate, etc. Alkoxy polyalkylene glycol (meth) acrylates and the like. (F) Polymers containing polyether structural units, for example, (co) polymers of ethylene oxide, butylene oxide, styrene oxide and the like, or derivatives thereof. (G) A sulfonated product of an aliphatic diene (co) polymer.

Other additives include, for example, alkali (earth) metals such as sodium hydroxide and potassium hydroxide, carbonates such as Na carbonate and amonium carbonate, and trifolylline.
Acid salts, phosphoric acid salts, phosphoric acid and other phosphates, water glass and other silicates, aluminate Na and other aluminates,
Aminocarboxylic acid salts such as ethylenediaminetetraacetic acid salt,
Examples thereof include hydroxycarboxylic acid salts such as citrate and gluconate, carboxylates such as acetate and oxalate, and other ion sequestering agents and chelating agents. Further, there may be mentioned inorganic clay minerals such as bentonite, attapulgite, sepiolite, montmorillonite and kaolin, and organic stabilizers such as xanthan gum, guar gum, cellulose, carboxymethyl cellulose and hydroxyethyl cellulose. Further, silicone-based and nonion-based antifoaming agents, freezing point depressants such as ethylene glycol, and polymerization inhibitors and antioxidants such as hydroquinone and phenol derivatives are listed.

The solid fuel used in the solid fuel slurry using the dispersant of the present invention is coal, petroleum coke, pitch or charcoal. Of these, coal is
It may be any of brown coal, sub-bituminous coal, bituminous coal, anthracite coal, etc., and may be coal which has been cleaned by deashing or the like, without any particular limitation. Petroleum coke is residual coke obtained by distilling cracked oil by thermally decomposing asphalt, pitch, etc. obtained as a heavy residue by distillation during petroleum refining at a higher temperature, and generally contains an inorganic substance. Compared to coal, it is extremely hard to get wet with water. Further, the pitch is a heavy residue obtained by distilling a heavy residue during petroleum distillation and tar obtained by coal dry distillation to leave an oil content, and the softening point thereof is preferably 50 to 180 ° C., and 50 ° C. If it is lower, crushing is difficult. Pitch can be made into a high calorific value slurry fuel containing almost no ash and water as compared with coal.

The particle size of these (D) solid fuels may be any particle size as long as they are powders. However, the pulverized coal currently burned in a thermal power plant has a 200 mesh pass and 70% by weight or more. Since it is a thing, this granularity serves as a rough guide. However, the dispersant of the present invention is not affected by the particle size and the type of solid fuel, and exerts an excellent effect on any solid fuel powder. The concentration of the solid fuel in the solid fuel slurry prepared by using the dispersant of the present invention is usually 50 to 85% by weight, preferably 60 to 85% by weight.
It is 80% by weight.

The method for producing a slurry using the dispersant of the present invention is not particularly limited. For example, a method in which a solid fuel is previously pulverized by a dry method and then mixed in an aqueous solution in which a dispersant is dissolved, a method in which a solid fuel, water, and a dispersant are mixed in a mill and wet pulverized to prepare a slurry is optional. The method of can be implemented.

[0046]

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to the following examples. In the examples,% and parts are based on weight unless otherwise specified. Further, various measurement items in the examples were obtained as follows.

Weight-average molecular weight The weight-average molecular weight is determined by gel permeation chromatography (GPC), and in the case of the (co) polymer before sulfonation, polystyrene, (co) polymer sulfonate (salt) In the case of, it was converted using a calibration curve prepared using sodium polystyrene sulfonate as a standard sample. Here, the measurement conditions of GPC are as follows. (A) GPC measurement of (co) polymer before sulfonation Column; G4000HXL [manufactured by Tosoh Corporation] Detector; Tosoh Corporation, differential refractometer RI-8012 eluent; tetrahydrofuran flow rate; 1.0 ml / Min. Temperature; 40 ° C. sample concentration; 0.2% sample injection amount; 300 μl (b) GPC measurement of sulfonate (salt) of (co) polymer column; G3000PW × L [manufactured by Tosoh Corporation] 〃; GMPW × L [manufactured by Tosoh Corporation] 〃; GMPW × L (manufactured by Tosoh Corporation) Columns are connected in series in the order of to and the sample is introduced from the column side Detector: Tosoh Corporation, differential refractometer RI-8012 eluent; water / acetonitrile / sodium sulfate = 2,1
00/900/15 (weight ratio) Flow rate; 1.0 ml / min Temperature; 40 ° C. Sample concentration; 0.2% Sample injection volume; 300 μl

Ratio of Star Polymer (% ) The ratio of star polymer was determined from the coupling ratio. That is, the coupling rate shows the ratio of the star-shaped polymer in all the polymers, and was determined from the pattern area ratio of gel permeation chromatography. Number of branches The number of branches was determined by dividing the weight average molecular weight of the polymer after branching by the weight average molecular weight before branching. Sulfonic acid amount 20% of each sulfonic acid (salt) is used to measure the amount of sulfonic acid.
Prepare an aqueous solution and use dialysis membrane [Hanui Chemical Co., Ltd., Cell
ulose Diolyzer Tubing-VT351] was used to remove low molecular weight substances, and a purified sample was used. This sample was used as a cation exchange resin (Organo Corporation, Amberlite IR-11).
8 (H)] was ion-exchanged to completely convert it into an acid form, and the amount of the sulfonic acid was determined by potentiometric titration.

Synthesis of (co) polymer containing star-shaped polymer To an autoclave having an internal volume of 10 liters, 4,000 g of cyclohexane bubbling with dehydrated nitrogen, 50 g of tetrahydrofuran and 12.8 g of n-butyllithium were added, and the temperature was adjusted to 70. Continue stirring at ℃ 1000
After continuously adding g to carry out polymerization, a small amount of a small sample was taken out and the weight average molecular weight was measured. After 79.2 g of divinylbenzene was added to the remaining living polymer solution, stirring was further continued at 50 ° C. for 1 hour. Then, isopropyl alcohol was added as a polymerization terminator to terminate the polymerization. From the GPC patterns before and after the coupling, it was confirmed that part of the linear polymer was coupled to form a star polymer. The weight average molecular weight before adding divinylbenzene was 6000, and the weight average molecular weight of the star polymer after adding was 78,000. The proportion of star polymer was 90% and the proportion of linear polymer was 10%. The infrared absorption spectrum of this base polymer is
Absorption of divinylbenzene was observed 700 cm ^-1 and 800 cm ^-1. The (co) polymer containing the star polymer thus obtained is referred to as BP-1. (Co) polymer was synthesized by using the monomers and reagents shown in Table 1 in the same manner as in BP-1. (BP-2 to BP-13)

[0050]

[Table 1]

Reference Example 1 Sulfonation After removing the solvent in BP-1 which is a (co) polymer containing the above star polymer, 150 g of polymer was added to dioxane 5
It was dissolved in 00 g. On the other hand, 2,000 g of dioxane was added to a 5 liter separable flask and stirred for 20 to 3 times.
222 g of sulfuric anhydride was added dropwise at 0 ° C. to obtain a sulfuric anhydride / dioxane complex. Subsequently, a dioxane solution of the polymer and a sulfuric anhydride / dioxane complex were reacted at 25 ° C. for 4 hours to sulfonate. Then sodium hydroxide 120
After 1,500 g of an aqueous solution in which g was dissolved was added and neutralized at 80 ° C. for 1 hour, dioxane and water were removed by distillation to recover a sulfonated polymer. The weight average molecular weight of the star polymer of the sulfonated polymer measured by aqueous GPC was 200,000. The amount of sulfonic acid was 5.0 meq / g.

Reference Examples 2 to 13 Using the (co) polymers shown in Table 1, the sulfonation reaction was carried out in the same manner as in Reference Example 1 under the conditions shown in Table 2. The properties of the obtained sulfonated polymer are shown in Table 2.

[0053]

[Table 2]

Next, the slurrying performance of the obtained sulfonated polymer was examined. Examples 1 to 15 and Comparative Examples 1 to 3 As the solid fuel, pulverized coal obtained by finely pulverizing coal having the properties shown in Table 3 so as to be 80% for 200 mesh pass was used. To prepare the slurry, put the sulfonated polymer or water-soluble polymer shown in Table 3 in water in advance, put a predetermined amount of pulverized coal in it, and knead with a spatula made of stainless steel for 1 minute. Then, using a homomixer [manufactured by Tokushu Kika Co., Ltd.], the mixture was stirred at 3,000 rpm for 15 minutes. The results are shown in Tables 5-6.

[0055]

[Table 3]

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[Table 4]

[0057]

[Table 5]

[0058]

[Table 6]

As is clear from Table 4, the slurry using the dispersant of the present invention greatly improves the stability without impairing the fluidity. On the other hand, as is clear from Table 4, the stability becomes poor when the dispersant of the present invention is not used.

The slurry viscosity was evaluated by measuring the viscosity of the slurry prepared as described above at 25 ° C. The storage stability of the slurry is 2 in a container made of transparent acrylic pipe with an inner diameter of 80 mm.
The slurry was added to a depth of 0 cm, and the hardness of the slurry was evaluated after 60 days by evaluation. Further, the vibration stability of the slurry was as follows: the same amount of the slurry was put in the same container as used for storage stability, and the amplitude was 10 cm and 90 cp.
It was evaluated by applying a vibration at a frequency of m for 15 hours and measuring the hardness of the slurry.

Here, the hardness of the slurry is measured by measuring the diameter of 1
This was done by penetrating a 0 mm glass rod into the slurry. The evaluation criteria are as follows. ⊚: The glass rod penetrates to the bottom of the container by its own weight (about 60 g). ○: Push the glass rod by hand to penetrate to the bottom of the container. Δ: Even if the glass rod is pushed by hand, it does not penetrate to the bottom of the container. X: No penetration occurs even if the glass rod is pushed by hand.

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INDUSTRIAL APPLICABILITY The dispersant of the present invention is an excellent dispersant capable of significantly improving long-term storage stability and vibration stability without increasing the slurry viscosity when used in a solid fuel slurry. is there.

Front Page Continuation (72) Inventor Hisao Ono 2-11-24 Tsukiji, Chuo-ku, Tokyo Inside Nippon Synthetic Rubber Co., Ltd.

Claims (2)

[Claims] 1. A composition comprising at least one structural unit selected from aliphatic dienes and aromatic vinyl monomers, and
The sulfonated compound (salt) obtained by sulfonation of a star-shaped (co) polymer having an average number of branches of 2.3 or more is 10
Solid fuel slurry characterized by containing at least wt%
Dispersant. 2. 0.01-5% by weight of the dispersant of claim 1.
Solid fuel slurry containing.