JP2020163362A - Dispersion agent, dispersion body, electrode and resin composition - Google Patents

Abstract

To provide a dispersion agent capable of preparing a dispersion body excellent in dispersibility, flowability and storage stability with a small used amount compared to a conventional dispersion agent.SOLUTION: A dispersion agent is a copolymer including a unit derived from (meth)acrylonitrile and a unit derived from one or more monomers selected from the group consisting of an active hydrogen group-containing monomer, a basic monomer and alkyl (meth)acrylate, in which the copolymer contains 40-99 mass% of the unit derived from (meth)acrylonitrile and has a weight average molecular weight of 5,000-50,000.SELECTED DRAWING: None

Description

The present invention relates to a dispersant for an acrylonitrile copolymer.

In general, when manufacturing inks and the like, it is known that it is difficult to stably disperse pigments at a high concentration, which causes various problems in the manufacturing process and the product itself. For example, a dispersion containing a pigment consisting of fine particles often exhibits a high viscosity, which not only makes it difficult to remove and transport the product from the disperser, but also causes gelation during storage and is used in the worst case. It can even be difficult. Further, the surface of the colored object causes poor condition such as deterioration of gloss and poor leveling.

Therefore, a dispersant is generally used to maintain a good dispersed state. The dispersant has a structure of a part that adsorbs to the pigment and a part that has a high affinity for the dispersion medium, and the performance of the dispersant is determined by the balance of these two functional parts.

Generally, when the surface of a pigment is strongly hydrophobic, an adsorption mechanism that utilizes a parent-hydrophobic interaction that matches the surface of the pigment is used to adsorb the dispersant to the pigment, and a functional group is formed on the surface of the pigment. If it exists, an adsorption mechanism using acid / base on the surface is used.

For example, in the dispersion of carbon black and carbon nanotubes (hereinafter CNT), Patent Documents 1 and 2 disclose a method for preparing a dispersion using a polymer dispersant such as polyvinyl alcohol (hereinafter PVA) or polyvinylpyrrolidone (hereinafter PVP). ing. However, although polymer dispersants such as PVA and PVP have been shown to be effective in polar solvents such as N-methyl-2-pyrrolidone and water, they have not been shown to be effective in dispersion in other dispersion media.

Furthermore, since PVA and PVP are generally highly hydrophilic and have the property of being soluble in water, when used as a dispersant for carbon black, the water resistance of the coating film is lowered when the dispersion is used as a coating film. Problems occur. For example, when a carbon dispersion using PVA or PVP is used as the dispersion for a lithium-ion battery, problems such as deterioration of battery performance due to moisture absorption occur.

Further, PVA and PVP are highly hydrophilic and dispersibility in a hydrophilic solvent such as water or NMP can be ensured, but their solubility in other solvents is low, and it is difficult to develop them into hydrophobic solvents. Further, due to the high hydrophilicity of PVA and PVP, the wettability to pigments that are not highly hydrophilic is not sufficient, and the dispersion time tends to be relatively long in order to prepare a stable dispersion.

Japanese Unexamined Patent Publication No. 2014-193986 Japanese Unexamined Patent Publication No. 2003-157846

Michael J. O’Connel et al. Chemical Physics Letters, 13 July 2001, 265-271 Coloring of polyacrylonitrile and its copolymer https://www.jstage.jst.go.jp/article/koron1944/19/210/19_210_653/_pdf/-char/ja

An object of the present invention is to provide a dispersant capable of producing a dispersion having excellent dispersibility, fluidity and storage stability at a low amount of use as compared with conventional dispersants.

The present invention includes a unit derived from (meth) acrylonitrile and a unit derived from one or more monomers selected from the group consisting of an active hydrogen group-containing monomer, a basic monomer, and a (meth) acrylic acid alkyl ester. It is a polymer,
The copolymer relates to a dispersant containing 40 to 99% by mass of a unit derived from the (meth) acrylonitrile and having a weight average molecular weight of 5,000 to 50,000.

In addition, the present invention uses units derived from (meth) acrylonitrile and units derived from one or more monomers selected from the group consisting of active hydrogen group-containing monomers, basic monomers, and (meth) acrylic acid alkyl esters. It is a copolymer containing
The copolymer contains 40 to 99% by mass of a unit derived from acrylonitrile, and has a weight average molecular weight of 5,000 to 50,000.
The unit derived from acrylonitrile relates to a dispersant having a cyclic structure.

Further, the present invention is a copolymer containing a unit derived from acrylonitrile and a unit derived from (meth) acrylic acid.
The copolymer contains 40 to 99% by mass of a unit derived from the acrylonitrile and 1 to 25% by mass of a unit derived from (meth) acrylic acid, and has a weight average molecular weight of 5,000 to 50,000.
The present invention relates to a dispersant in which the unit derived from acrylonitrile and the (meth) acrylic acid unit form a cyclic structure.

The present invention also relates to a dispersion containing a dispersion medium, the above-mentioned dispersant, and a dispersant.

The present invention also relates to the above-mentioned dispersion in which the object to be dispersed is a conductive material.

The present invention also relates to the above dispersion further comprising at least one selected from the group consisting of inorganic metal salts, inorganic bases and organic bases.

The present invention also relates to a resin composition containing the above dispersion and a binder resin.

The present invention further relates to the above resin composition containing an active material.

The present invention also relates to an electrode including an electrode layer and a mixture layer formed of the above resin composition.

The present invention also relates to a dispersion containing the above-mentioned dispersant, a colorant, and one or more objects to be dispersed selected from the group consisting of cellulose fibers.

INDUSTRIAL APPLICABILITY According to the present invention, it is possible to provide a dispersant capable of producing a dispersion having excellent dispersibility, fluidity and storage stability at a low amount of use as compared with a conventional dispersant.

First, the terms used herein are defined.
The monomer is an ethylenically unsaturated group-containing monomer. (Meta) acrylic monomers include (meth) acrylic acid esters and (meth) acrylic acids.

<Dispersant>
The dispersant of the present invention is derived from a monomer unit derived from (meth) acrylonitrile and one or more monomers selected from the group consisting of an active hydrogen group-containing monomer, a basic monomer, and a (meth) acrylic acid alkyl ester. It is a copolymer containing the unit to be used, and the copolymer contains 40 to 99% by mass of the monomer unit derived from the (meth) acrylonitrile, preferably as the content of the unit derived from (meth) acrylonitrile. Is 50 to 99% by mass, more preferably 75 to 99% by mass. The dispersant of the present invention can be synthesized by either a random polymerization method or a block polymerization method.
The dispersant of the present invention contains a high concentration of units derived from (meth) acrylonitrile. The strong polarization of the non-hydrogen-bonding cyano group and the carbon chain of the dispersion resin main chain enhance the adsorption to the dispersion and the affinity for the dispersion medium, and the dispersion can be stably present in the dispersion medium. it can.

The dispersant of the present invention is preferably used in applications such as offset inks, gravure inks, resist inks for color filters and ink jet inks, paints, conductive materials, and colored resin compositions. The dispersant of the present invention suppresses the reaggregation of the object to be dispersed and has excellent fluidity, so that good dispersion stability can be obtained.

The active hydrogen group-containing monomer in the present invention will be described. The active hydrogen group-containing monomer is not particularly limited as long as it has one or more active hydrogen groups in one molecule, and the active hydrogen groups are a hydroxyl group, a carboxyl group, a primary amino group, a secondary amino group, and a mercapto. It is a group.

Hydroxy group-containing monomers include, for example, 2-hydroxyethyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, glycerol mono (meth) acrylate, 4-hydroxyvinylbenzene, 2-. Hydroxy-3-phenoxypropyl acrylate or a caprolactone adduct of these monomers (additional number of moles is 1 to 5) and the like can be mentioned.

Carboxylic group-containing monomers include, for example, (meth) acrylic acid, (meth) acrylic acid dimer, itaconic acid, maleic anhydride, fumaric acid, crotonic acid, 2- (meth) acryloyloxyethyl phthalate, 2- (meth) acrylic. Loyloxypropyl phthalate, 2- (meth) acryloyloxyethyl hexahydrophthalate, 2- (meth) acryloyloxypropyl hexahydrophthalate, ethylene oxide-modified succinic acid (meth) acrylate, β-carboxyethyl (meth) acrylate, And monofunctional alcohol adducts of acid anhydride group-containing monomers such as maleic anhydride, itaconic anhydride, and citraconic acid.

Examples of the primary amino group-containing monomer include aminomethyl (meth) acrylate, aminoethyl (meth) acrylate, allylamine hydrochloride, allylamine dihydrogen phosphate, 2-isopropenylaniline, 3-vinylaniline, and 4-vinylaniline. And so on.

Examples of the secondary amino group-containing monomer include t-butylaminoethyl (meth) acrylate and the like.

Examples of the mercapto group-containing monomer include 2- (mercaptoacetoxy) ethyl acrylate, allyl mercaptan and the like.

From the viewpoint of easy availability of raw materials, ease of handling, and compatibility with a dispersion medium described later, hydroxyl group-containing monomers and hydroxyethyl (meth) acrylates and (meth) acrylic acids, which are carboxyl group-containing monomers, are preferable, and more preferable. Is hydroxyethyl acrylate, acrylic acid.

Next, the basic monomer will be described. The basic monomer in the present invention is a basic monomer that does not contain a primary amino group or a secondary amino group.

For example, dialkylaminoalkyl (meth) acrylates such as dimethylaminoethyl (meth) acrylate and dimethylaminopropyl (meth) acrylate;
N-substituted (meth) acrylamides such as (meth) acrylamide, N, N-diethyl (meth) acrylamide, N-isopropyl (meth) acrylamide, and acryloyl morpholine;
Heterocyclic aromatic amine-containing vinyl monomers such as 1-vinylpyridine, 4-vinylpyridine and 1-vinylimidazole N-substituted maleimides such as N-phenylmaleimide and N-cyclohexylmaleimide;
N- (alkylaminoalkyl) (meth) acrylamides such as N- (dimethylaminoethyl) (meth) acrylamide and N- (dimethylaminopropyl) acrylamide;
Examples thereof include N, N-alkyl (meth) acrylamides such as N, N-dimethyl (meth) acrylamide and N, N-diethyl (meth) acrylamide.

Dimethylaminoethyl (meth) acrylate and dimethylaminopropyl (meth) acrylate are preferable, and dimethylaminoethyl acrylate is most preferable, from the viewpoint of easy availability of raw materials, ease of handling, and affinity with a dispersion medium described later.

Next, the (meth) acrylic acid alkyl ester will be described. The (meth) acrylic acid alkyl ester of the present invention has a C = C-CO-O-skeleton, has an alkyl group having 1 or more carbon atoms, and is particularly free from active hydrogen or a basic group. There is no limitation, for example, a (meth) acrylic acid ester containing a chain aliphatic alkyl group such as methyl (meth) acrylate and ethyl (meth) acrylate;
A (meth) acrylic acid ester containing a branched aliphatic alkyl group such as 2-ethylhexyl (meth) acrylate and isostearyl (meth) acrylate;
Cyclic aliphatic alkyl group-containing (meth) acrylic acid ester such as cyclohexyl (meth) acrylate and isobornyl (meth) acrylate;
(Meta) acrylic acid alkyl esters substituted with aromatic groups such as (meth) benzyl acrylate and (meth) phenoxyethyl acrylate;
(Meta) acrylic acid alkyl esters substituted with fluoro groups such as trifluoroethyl (meth) acrylic acid and tetrafluoropropyl (meth) acrylic acid;
(Meta) acrylic acid alkyl esters substituted with alicyclic epoxy groups such as glycidyl (meth) acrylic acid and (3-ethyloxetane-3-yl) methyl (meth) acrylic acid;
(Meta) acrylic acid alkyl esters substituted with silyl ether groups such as 3-methacryloxypropylmethyldimethoxysilane;
(Meta) acrylic acid alkyl esters substituted with alkylene glycol monoalkyl ether groups such as 2-methoxyethyl (meth) acrylic acid and polyethylene glycol monomethyl ether (meth) acrylic acid;
Examples thereof include cyclized polymerizable monomers such as 2- (allyloxymethyl) methyl acrylate.

Ethyl (meth) acrylate, butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, (meth) acrylic acid from the viewpoint of availability of raw materials, ease of handling, and compatibility with dispersion media described later. Lauryl is preferable, and 2-ethylhexyl acrylate and lauryl acrylate are more preferable.

The dispersant of the present invention may further copolymerize the other monomer components described above. Other monomers include, for example, styrene and styrenes such as α-methylstyrene;
Vinyl ethers such as ethyl vinyl ether, n-propyl vinyl ether, isopropyl vinyl ether, n-butyl vinyl ether, and isobutyl vinyl ether;
Vinyl acetate and fatty acid vinyls such as vinyl propionate;
Heterocyclic (meth) acrylates such as tetrahydrofurfreel (meth) acrylate or 3-methyloxetanyl (meth) acrylate; and the like can be mentioned.

The dispersant of the present invention can disperse various objects to be dispersed such as a conductive material, a colorant, and a cellulose fiber. Further, when the dispersant of the present invention has the following active hydrogen group-containing monomer units depending on the type of dispersion medium, the dispersion stability is further improved. For example, when water is used as a dispersion medium, it preferably contains a (meth) acrylic acid unit. When NMP (N-methylpyrrolidone) is used as a dispersion medium, it preferably contains a hydroxyl group-containing monomer unit such as 2-hydroxyethyl (meth) acrylate.

The method for producing the dispersant of the present invention is not particularly limited, and any method such as a solution polymerization method, a suspension polymerization method, a massive polymerization method, an emulsion polymerization method, or a precipitation polymerization method may be used, and the present invention may be used. In the above, solution polymerization or precipitation polymerization method is preferable. As the polymerization reaction system, addition polymerization such as ionic polymerization, free radical polymerization, and living radical polymerization can be used, and in the present invention, free radical polymerization or living radical polymerization is preferable. Further, as the radical polymerization initiator, a compound selected from peroxides, azo-based initiators and the like, or a mixture thereof can be used, and if necessary, a molecular weight modifier such as a chain transfer agent may be used.

The dispersant of the present invention preferably contains 40 to 99% by mass of a unit derived from (meth) acrylonitrile, and more preferably 50 to 99% by mass, and particularly preferably 75 to 99% by mass. By containing a unit derived from (meth) acrylonitrile in the above range, the adsorptivity to the dispersion and the affinity to the dispersion medium can be controlled, and the dispersion can be stably present in the dispersion medium. Can be done.

The molecular weight of the dispersant of the present invention is a polystyrene-equivalent weight average molecular weight, usually in the range of 5,000 or more and 50,000 or less, more preferably 6,000 or more and 40,000 or less, and particularly preferably 7,000 or more and 30,000 or less. If the molecular weight of the dispersant is less than 5,000 or more than 50,000, the adsorptivity to the object to be dispersed and the affinity for the dispersion medium tend to decrease, and the stability of the dispersion tends to decrease.

The dispersant of the present invention is excellent in dispersibility, fluidity, and storage stability even if the copolymer is used as it is, and when the unit derived from acrylonitrile has a cyclic structure, these characteristics are further improved. When the copolymer is treated with alkali, the unit derived from acrylonitrile changes to a cyclic structure such as a hydrogenated diazanaphthalene ring. In the present specification, the presence of the cyclic structure further improves the dispersibility. The alkali treatment may be performed at an arbitrary timing after the copolymer is synthesized and immediately before it is used as a dispersant.

When the copolymer has a (meth) acrylic acid unit, it forms a glutarimide ring as a cyclic structure together with a unit derived from acrylonitrile by alkali treatment, so that it has a ring structure such as a hydrogenated diazanaphthalene ring and a glutarimide ring. Coexist. The (meth) acrylic acid unit is preferably 1 to 25% by mass, more preferably 10 to 25% by mass, based on all the monomer units of the copolymer. The unit derived from acrylonitrile is preferably 40 to 99% by mass, more preferably 75 to 99% by mass, based on all the monomer units of the copolymer.

<Dispersion>
The dispersant of the present invention can coexist with the object to be dispersed in the dispersion medium and can be used as a dispersion. Examples of the dispersant include colorants such as organic pigments, inorganic pigments as conductive materials, inorganic pigments as insulating materials, and polymers such as cellulose fibers. Further, the dispersion preferably contains a dispersion medium.

Examples of the organic pigment in the present invention include various pigments used for inks and the like. Such pigments include soluble azo pigments, insoluble azo pigments, phthalocyanine pigments, quinacridone pigments, isoindolinone pigments, isoindolin pigments, perylene pigments, perinone pigments, dioxazine pigments, anthraquinone pigments, dianthraquinonyl pigments, and anthrapyrimidine pigments. , Ansanthron pigment, Indanthron pigment, Flavanthron pigment, Pyranthron pigment, Diketopyrrolopyrrole pigment, etc. More specific examples are shown by the generic name of the color index: Pigment Black 7, Pigment Blue 6, 15 , 15: 1,15: 3,15: 4,15: 6,60, Pigment Green 7,36, Pigment Red 9,48,49,52,53,57,97,122,144,146,149,166 , 168,177,178,179,185,206,207,209,220,221,238,242,254,255, Pigment Violet 19,23,29,30,37,40,50, Pigment Yellow 12,13 , 14, 17, 20, 24, 74, 83, 86, 93, 94, 95, 109, 110, 117, 120, 125, 128, 137, 138, 139, 147, 148, 150, 151, 154, 155. , 166,168,180,185, Pigment Orange 13,36,37,38,43,51,55,59,61,64,71,74 and the like. However, it is not limited to the examples.

In the present invention, the conductive material is, for example, gold, silver, copper, silver-plated copper powder, silver-copper composite powder, silver-copper alloy, amorphous copper, nickel, chromium, palladium, rhodium, ruthenium, indium, silicon, aluminum, tungsten. , Morbutene, metal powders such as platinum, inorganic powders coated with these metals, powders of metal oxides such as silver oxide, indium oxide, tin oxide, zinc oxide, ruthenium oxide, inorganic substances coated with these metal oxides. Powder, carbon black, graphite and the like can be used. As for carbon black, any carbon black such as neutral, acidic, and basic can be used. These conductive materials may be used alone or in combination of two or more. Among these conductive materials, carbon black is preferable.

As the carbon black used in the present invention, various commercially available acetylene black, furnace black, hollow carbon black, channel black, thermal black, Ketjen black and the like can be used. Further, the usual oxidation-treated carbon black, graphitized carbon black, carbon nanotubes, carbon nanofibers, and the like can also be used.

In the present invention, the insulating material is, for example, titanium dioxide, iron oxide, antimony pentoxide, zinc oxide, etc.
Examples thereof include metal oxides such as silica, cadmium sulfide, calcium carbonate, barium carbonate, barium sulfate, clay, talc, and yellow lead.

From the viewpoint of the adsorption performance of the dispersant in the present invention, the dispersant is preferably carbon black containing carbon nanotubes and carbon nanofibers.

Further, the dispersant of the present invention includes organic fibers such as aromatic polyamide (aramid) fibers, acrylic fibers, cellulose fibers and phenol resin fibers, and metal fibers such as steel fibers, copper fibers, alumina fibers and zinc fibers; glass fibers, It can also be used for inorganic fibers such as rock wool, ceramic fibers, biodegradable fibers, biosoluble fibers, and wallastonite fibers; carbon fibers; and other fibrous compounds, and is particularly preferably used for cellulose fibers. Can be done.

The dispersion of the present invention can contain an inorganic base, an inorganic metal salt, or an organic base. This further improves the dispersion stability of the object to be dispersed over time. The inorganic base and the inorganic metal salt are preferably compounds having at least one of an alkali metal and an alkaline earth metal, and more particularly, chlorides, hydroxides and carbonates of the alkali metal and the alkaline earth metal. Examples thereof include salts, nitrates, sulfates, phosphates, tungstates, vanadium salts, molybdates, niobates, borates and the like. Further, among these, alkali metals, chlorides of alkaline earth metals, hydroxides and carbonates are preferable in terms of easily supplying cations. Examples of the alkali metal hydroxide include lithium hydroxide, sodium hydroxide, potassium hydroxide and the like.
Examples of the hydroxide of the alkaline earth metal include calcium hydroxide and magnesium hydroxide.
Examples of the alkali metal carbonate include lithium carbonate, lithium hydrogen carbonate, sodium carbonate, sodium hydrogen carbonate, potassium carbonate, potassium hydrogen carbonate and the like.
Examples of carbonates of alkaline earth metals include calcium carbonate and magnesium carbonate. Among these, lithium hydroxide, sodium hydroxide, lithium carbonate and sodium carbonate are more preferable. The metal contained in the inorganic base and the inorganic metal salt of the present invention may be a transition metal.

Examples of the organic base include primary, secondary and tertiary alkylamines having 1 to 40 carbon atoms.

Primary alkylamines having 1 to 40 carbon atoms include propylamine, butylamine, isobutylamine, octylamine, 2-ethylhexylamine, laurylamine, stearylamine, oleylamine, 2-aminoethanol, 3-aminopropanol, and 3-ethoxy. Examples thereof include propylamine and 3-lauryloxypropylamine.

Examples of the secondary alkylamine having 1 to 40 carbon atoms include dibutylamine, diisobutylamine, N-methylhexylamine, dioctylamine, distearylamine, 2-methylaminoethanol and the like.

Examples of tertiary alkylamines having 1 to 40 carbon atoms include triethylamine, tributylamine, N, N-dimethylbutylamine, N, N-diisopropylethylamine, dimethyloctylamine, trioctylamine, dimethyldecylamine, dimethyllaurylamine, and dimethylmyristyl. Examples thereof include amines, dimethyl palmitylamines, dimethylstearylamines, dilaurylmonomethylamines, triethanolamines, 2- (dimethylamino) ethanols and the like.

Of these, primary, secondary or tertiary alkylamines having 1 to 30 carbon atoms are preferable, and primary, secondary or tertiary alkylamines having 1 to 20 carbon atoms are even more preferable.

As organic bases, 1,8-diazabicyclo [5.4.0] undecene-7 (DBU), 1,5-diazabicyclo [4.3.0] nonen-5 (DBN), 1,4-diazabicyclo [2] .2.2] Compounds containing a basic nitrogen atom such as octane (DABCO), tri-n-butylamine, dimethylbenzylamine, monoethanolamine, imidazole, and 1-methylimidazole may be used.

The blending amount of the inorganic base, the inorganic metal salt, and the organic base is more preferably 1 to 50 parts by mass with respect to 100 parts by mass of the dispersant. Dispersibility is further improved when an appropriate amount is blended.

<Dispersion medium>
The dispersion medium is not particularly limited. Examples of the dispersion medium include water, a water-soluble solvent, and a water-insoluble solvent. Examples of the water-soluble solvent include; alcohol-based dispersion media such as ethanol, propanol, butanol, methyl cellosolve, butyl cellosolve, and propylene glycol monomethyl ether; The water-insoluble solvent is, for example, a ketone dispersion medium such as acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone; an ether dispersion medium such as tetrahydrofuran; an aromatic dispersion medium such as toluene, xylene, mesitylene; dimethylformamide, dimethylacetamide. Nitrogen atom-containing dispersion medium including amide-based dispersion medium such as N-methylpyrrolidone; Sulfur atom-containing dispersion medium including sulfoxide-based dispersion medium such as dimethyl sulfoxide; Ethyl acetate, butyl acetate, propylene glycol monomethyl ether acetate, γ -Ester-based dispersion media such as butyrolactone can be mentioned.

<Dispersion method>
In the dispersant of the present invention, the dispersant is placed in a dispersant carrier such as a dispersant and a binder resin and / or a dispersion medium in a kneader, two roll mills, three roll mills, a ball mill, a horizontal sand mill, a vertical sand mill, and the like. It can be finely dispersed and manufactured by using various dispersion means such as an annular type bead mill or an attritor. At this time, two or more kinds of objects to be dispersed or the like may be simultaneously dispersed in the carrier and / or dispersion medium to be dispersed, or separately dispersed substances may be mixed.

<Binder resin>
When the dispersion is prepared using the dispersant of the present invention, a binder resin may be further contained. The binder resin used depends on the application, but ethylene, propylene, vinyl chloride, vinyl acetate, vinyl alcohol, maleic acid, acrylic acid, acrylic acid ester, methacrylic acid, methacrylic acid ester, acrylonitrile, styrene, vinyl butyral, vinyl. Polymers or copolymers containing acetal, vinylpyrrolidone, etc. as constituent units; polyurethane resin, polyester resin, phenol resin, epoxy resin, phenoxy resin, urea resin, melamine resin, alkyd resin, acrylic resin, formaldehyde resin, silicon resin, Fluororesin; Cellulosic resin such as carboxymethyl cellulose; Rubbers such as styrene-butadiene rubber and fluororubber; Conductive resins such as polyaniline and polyacetylene. Further, modified products and mixtures of these resins and copolymers may be used.

The dispersion of the present invention preferably contains a dispersant and a dispersant. Examples of the object to be dispersed include the conductive material, the colorant, and the cellulose fiber already described.
In this specification, first, the use of the dispersant and the use of conductivity will be described.
Examples of conductive applications include power storage devices, antistatic materials, electronic components, transparent electrode (ITO film) substitutes, electromagnetic wave shields, and the like.
Examples of the power storage device include an electrode for a lithium ion secondary battery, an electrode for an electric double layer capacitor, an electrode for a lithium ion capacitor, and the like. In this case, the conductive material is preferably a carbon material.
Examples of the antistatic material include IC trays of plastic and rubber products and molded bodies of electronic component materials.

<Active material>
When the dispersion of the present invention is used for the mixture layer of the electrodes of the secondary battery, a positive electrode active material or a negative electrode active material can be further contained.

<Positive electrode active material>
The positive electrode active material used is not particularly limited as long as it functions as an active material for a battery. For example, when used in a lithium ion secondary battery, a metal oxide capable of doping or intercalating lithium ions, a metal compound such as a metal sulfide, a conductive polymer, or the like can be used.

Specifically, lithium manganese composite oxide (eg LixMn2O4 or LixMnO2), lithium nickel composite oxide (eg LixNiO2), lithium cobalt composite oxide (LixCoO2), lithium nickel cobalt composite oxide (eg LixNi1-yCoyO2), lithium. Lithium-transition metal such as manganese-cobalt composite oxide (eg LixMnyCo1-yO2), lithium nickel manganese cobalt composite oxide (eg LixNyCozMn1-y-zO2), spinel-type lithium manganese-nickel composite oxide (eg LixMn2-yNiyO4) Composite oxide powder, lithium phosphorus oxide powder having an olivine structure (for example, LixFePO4, LixFe1-yMnyPO4, LixCoPO4, etc.), manganese oxide, iron oxide, copper oxide, nickel oxide, vanadium oxide (for example, V2O5, V6O13), titanium oxide Examples thereof include transition metal oxide powders such as iron sulfate (Fe2 (SO4) 3), TiS2, and transition metal sulfide powders such as FeS. However, x, y, and z are numbers, and 0 <x <1, 0 <y <1, 0 <z <1, 0 <y + z <1. In addition, conductive polymers such as polyaniline, polyacetylene, polypyrrole, and polythiophene can also be used. These positive electrode active materials may be used alone or in combination of two or more.

<Negative electrode active material>
The negative electrode active material to be used is not particularly limited, but is a metal Li capable of doping or intercalating lithium ions, or a metal oxide system such as an alloy thereof, a tin alloy, a silicon alloy negative electrode, LiXTIO2, LiXFe2O3, LiXFe3O4, or LiXWO2. , Polyacetylene, Poly-p-Phenylene and other conductive polymers, Amorphous carbon materials such as soft carbon and hard carbon, artificial graphite such as highly graphitized carbon materials, or carbon powder such as natural graphite, carbon black, Carbon-based materials such as mesophase carbon black, resin-fired carbon material, vapor-grown carbon fiber, and carbon fiber are used. However, x is a number, and 0 <x <1. These negative electrode active materials may be used alone or in combination of two or more.

The electrode of the present invention preferably includes an electrode layer and a mixture layer formed of a resin composition.
For the electrode layer, a material applicable to various secondary batteries may be selected. For example, metals such as aluminum, copper, nickel, titanium, and stainless steel, and alloys thereof. Examples of the shape of the electrode layer include a flat plate foil and a mesh shape. The surface of the electrode layer may be roughened or perforated.
The thickness of the electrode layer is usually about 1 to 500 μm.

The mixture layer is preferably formed by applying a slurry-like resin composition on the electrode layer and drying it. In addition, after coating, rolling processing can be performed by a lithographic press, a calendar roll, or the like.
Examples of the coating method include a die coating method, a dip coating method, a roll coating method, a doctor coating method, a knife coating method, a spray coating method, a gravure coating method, a screen printing method, an electrostatic coating method and the like. Examples of the drying method include hot air drying and an infrared heater.

The thickness of the mixture layer is usually about 1 to 300 μm.

In the dispersion of the present invention, it is preferable that the dispersant other than the conductive material is one or more selected from the group consisting of a colorant and a cellulose fiber.
When the object to be dispersed is a colorant, for example, organic pigments, inorganic pigments, dyes and the like can be mentioned. In this case, the use of the dispersion includes, for example, offset ink, gravure ink, resist ink for color filter, ink jet ink, paint, resin composition for molding and the like.

When the object to be dispersed is a cellulose fiber (including, for example, cellulose nanofiber), the application thereof is, for example, high heat resistance, low linear expansion rate, high elastic modulus, high strength, and high transparency of the cellulose fiber. Examples of applications that make use of the properties include adhesives, various paints, packaging materials, gas barrier materials, electronic members, molded bodies, structures and the like.

Hereinafter, the present invention will be described in more detail, but the present invention is not limited to these examples. In addition, "mass%" is described as "%". The blending amount in the table is mass%.

The evaluation of various physical properties of the dispersant of the present invention, the molecular weight of the binder resin, and the dispersion using the dispersant of the present invention is as follows.

(Measuring method of weight average molecular weight (Mw))
The weight average molecular weight (Mw) was measured by gel permeation chromatography (GPC) equipped with an RI detector.
The device used HLC-8320GPC (manufactured by Tosoh), three separation columns were connected in series, and the fillers were "TSK-GELSUPERAW-4000", "AW-3000", and "AW-2500" manufactured by Tosoh in order. , An oven temperature of 40 ° C., a solution of 30 mM triethylamine and 10 mM LiBr in N, N-dimethylformamide as an eluent, and the measurement was performed at a flow rate of 0.6 ml / min. The sample was prepared in a solvent consisting of the above eluent at a concentration of 1 wt%, and 20 microliters were injected. The molecular weight is a polystyrene-equivalent value.

(Method for measuring viscosity of dispersion)
To measure the viscosity, use a B-type viscometer (“BL” manufactured by Toki Sangyo Co., Ltd.), stir the dispersion sufficiently with a spatula at a dispersion temperature of 25 ° C, and then rotate the rotor of the B-type viscometer at 60 rpm. I went immediately at. When the viscosity of the rotor used for the measurement was less than 100 mPa · s, No. If 1 is 100 or more and less than 500 mPa · s, No. If 2 is 500 or more and less than 2000 mPa · s, No. If 3 is 2000 or more and less than 10000 mPa · s, No. Each of 4 was used. The lower the viscosity, the better the dispersibility, and the higher the viscosity, the poorer the dispersibility. Those in which the obtained dispersion was clearly separated or settled were regarded as poor dispersibility.
Judgment criteria other than cellulose fibers are as follows.
◎ +: Less than 30 mPa · s (good)
⊚: Less than 50 mPa · s (good)
◯: 50 or more and less than 1000 mPa · s (usable)
Δ: 1000 or more and less than 10000 mPa · s (cannot be used)
X: 10000 mPa · s or more, settling or separation (defective)
The criteria for determining cellulose fibers are as follows.
⊚: Less than 500 mPa · s (good)
◯: 500 or more and less than 10000 mPa · s (usable)
X: 10000 mPa · s or more, settling or separation (defective)

(Dispersion stability evaluation method)
To evaluate the storage stability, the viscosity of the dispersion after standing at 50 ° C. for 7 days was measured. The measuring method was the same as the initial viscosity. The evaluation criteria are as follows.
⊚: No change in viscosity (change rate less than 3%) (good)
〇: Viscosity changed slightly (change rate 3% or more and less than 10%) (usable)
Δ: Viscosity changed (change rate 10% or more) (cannot be used)
X: The solution gelled, settled, or separated (defective)

(Manufacturing Example 1)
(Manufacturing of dispersant (A-1))
100 parts of acetonitrile was charged in a reaction vessel equipped with a gas introduction tube, a thermometer, a condenser, and a stirrer, and replaced with nitrogen gas. The inside of the reaction vessel is heated to 70 ° C. to add 50.0 parts of acrylonitrile, 25.0 parts of acrylic acid, 25.0 parts of styrene and 2,2'-azobis (2,4-dimethylvaleronitrile) (NOF). Co., Ltd .; V-65) 5.0 parts of the mixture was added dropwise over 3 hours to carry out a polymerization reaction. After completion of the dropping, the reaction was further carried out at 70 ° C. for 1 hour, 0.5 part of perbutyl O was added, and the reaction was further continued at 70 ° C. for 1 hour. Then, it was confirmed by measuring the non-volatile content that the conversion rate exceeded 98%, and the mixture was concentrated under reduced pressure to completely remove the dispersion medium to obtain a dispersant (A-1). The weight average molecular weight (Mw) of the dispersant (A-1) was 15,000.

(Manufacturing Examples 2 to 13)
(Manufacturing of Dispersants (A-2) to (A-13))
Dispersants (A-2) to (A-13) were produced in the same manner as in Example 1 except that the monomers used were changed according to Table 1. The weight average molecular weight (Mw) of each dispersant was as shown in Table 1. In the synthesis of the dispersant, Mw was prepared by appropriately changing the addition of the chain transfer agent, the adjustment of the amount of the polymerization initiator, the reaction conditions, and the like.

AA: HEA acrylate: Hydroxyethyl acrylate DMAEA: Dimethylaminoethyl acrylate BA: Butyl acrylate 2EHMA: 2-Ethylhexyl acrylate AOMA: 2-[(allyloxy) methyl] Methyl acrylate

(Manufacturing of dispersant (A-14))
50 parts of the dispersant (A-3) obtained in Production Example 3 was added to 198 parts of purified water and stirred with a disper to form a slurry. Next, 2.0 parts of a 1N aqueous sodium hydroxide solution was added dropwise at 25 ° C., and the mixture was stirred with a disper for 2 hours. It was confirmed by IR measurement (apparatus: FT / IR-410, manufactured by JASCO Corporation) that the peak intensity derived from the cyano group was reduced to 80% or less, and the formation of a cyclic structure was confirmed. Then, it was washed with purified water and dried by filtration to obtain a dispersant (A-14) having a hydrogenated diazanaphthalene ring and a glutarimide ring. The weight average molecular weight (Mw) was 14,000.

(Manufacturing of dispersant (A-15))
A dispersant (A-15) having a hydrogenated naphthylidine ring was obtained in the same manner as in Production Example 13 except that the dispersant used was changed from (A-3) to (A-6). The weight average molecular weight (Mw) was 14,000.

<Creation of carbon black dispersion>
[Examples 1 to 35, Comparative Examples 1 to 7]
According to the composition shown in Table 2, carbon black, a dispersant, an additive, and a dispersion medium are charged as a conductive material in a glass bottle, and after sufficiently mixing and dissolving or mixing, 1.25 mmφ zirconia beads are used as a medium and a paint conditioner is used. After time dispersion, each carbon black dispersion was obtained. As shown in Table 2, all of the dispersions 1 to 35 using the dispersant of the present invention had low viscosity and good storage stability.

HS-100: Denka Black HS-100 (manufactured by Denka, acetylene black, average primary particle diameter 48 nm, specific surface area 39 m2 / g)
-# 30: Mitsubishi Chemical Corporation, furnace black, average primary particle diameter 30 nm, specific surface area 74 m2 / g
-EC-300J: Made by Lion Specialty Chemicals, Ketjen Black, average primary particle diameter 40 nm, specific surface area 800 m2 / g
・ 8A: JENOTUBE8A JEIO, multi-walled CNT, outer diameter 6-9nm
100T: K-Nanos100T (manufactured by Kumho Petrochemical, multi-walled CNT, outer diameter 10 to 15 nm)
-PVP: Nippon Shokubai, polyvinylpyrrolidone K-30, 100% non-volatile content
-PVA: Kuraray POVAL PVA403, 100% non-volatile content
-NMP: N-methylpyrrolidone-MEK: Methyl ethyl ketone-PGMAc: Propylene glycol monomethyl ether acetate

<Creation of colorants, cellulose fibers, and inorganic oxide dispersions>
[Examples 36 to 42, Comparative Examples 8 to 10]
According to the composition shown in Table 3, the dispersant, dispersant, additive, and dispersion medium are charged in a glass bottle, and after sufficient mixing and dissolution or mixing, various dispersants are added and 0.5 mmφ zirconia beads are used as media. , Dispersed with a paint conditioner for 2 hours to obtain each dispersion. As shown in Table 3, all of the dispersions 26 to 32 using the dispersant of the present invention had low viscosity and good storage stability.

P-1: Phthalocyanine-based green pigment C.I. I. Pigment Green 58 (DIC Corporation "FASTOGENGREEN A110")
P-2: Copper phthalocyanine blue pigment PB15: 6 (Toyo Color Co., Ltd. "Rionol Blue ES")
P-3: Kinophthalone yellow pigment PY138 (BASF's "Pariotor Yellow K0961HD")
P-4: Anthraquinone-based red pigment C.I. I. Pigment Red 177 (BASF's "Chromophtal Red A2B"
P-5: Cellulose fiber (Daicel's "Cerish KY100G"
P-6: Titanium oxide ("CR-95" manufactured by Ishihara Sangyo Co., Ltd.)
P-7: Zirconium oxide powder (Nippon Denko Co., Ltd. "PCS")

[Examples 43 to 77, Comparative Examples 11 to 17]
(Conductive coating film formed using carbon black dispersion)
The dispersions 1 to 35 prepared in Examples 1 to 35 and the binder resin were blended with each dispersion so that the non-volatile components and the carbon concentrations in the non-volatile components were as shown in Table 4 to prepare a carbon dispersion. did. A dispersion prepared using the bar coater was applied to the surface of a PET film having a thickness of 100 μm using a bar coater, and then dried at 130 ° C. for 30 minutes to form a coating film having a thickness of 5 μm. The surface resistance value of the coating film was measured using a resistivity meter (trade name "Hiresta", manufactured by Mitsubishi Chemical Analytech Co., Ltd.). The results are shown in Table 4.
⊚: 1.0 × 104Ω / cm less than 2 (good)
◯: 1.0 × 104 or more and less than 1.0 × 107Ω / cm2 (usable)
Δ: 1.0 × 107 or more and less than 1.0 × 1010 Ω / cm2 (usable)
X: 1.0 × 1010 Ω / cm2 or more, settling or separation (defective)

Water resistance: The coated plate obtained in Examples 43 to 77 or Comparative Example was immersed in warm water at 25 ° C. for 2 hours, pulled up, and water droplets on the surface were wiped off, and then the state of the coating film was visually evaluated. The results are shown in Table 4.
Judgment criteria ⊚: There is no change in the coating film.
〇: Whitening was seen on the coated surface, but it returned to its original state after being left for 24 hours.
X: The coating film was significantly whitened and was easily peeled off by light rubbing.

-CMC: Daicel Fine Chem Ltd., Carboxymethyl Cellulose # 1120, 100% non-volatile content
-PVDF: Made by Kureha, polyvinylidene fluoride, KF polymer W1100 100% non-volatile content

From the above results, when the dispersant of the present invention was used, a dispersion having excellent dispersion efficiency, dispersibility, fluidity, and storage stability could be produced. In particular, a dispersant containing an active hydrogen group-containing monomer or a basic monomer is preferable for a hydrophilic solvent system such as water or NMP as the dispersion medium, and a (meth) acrylic acid alkyl ester is preferable for a solvent such as butyl acetate, MEK or PGMAc. The dispersant containing the above was excellent.
Further, from Comparative Example 7 in Table 2, the conventional dispersant had a certain degree of dispersibility when the amount used was increased, but the dispersibility decreased when the amount used was decreased. On the other hand, the dispersant of the present invention had good dispersibility even when the amount used was reduced.
In addition, the dispersant of the present invention was able to produce a dispersion having excellent dispersibility, fluidity, and storage stability not only for the conductive material but also for the object to be dispersed other than the conductive material.
When the dispersant of the present invention is used for a power storage device application, an electrode having excellent conductivity and good water resistance can be obtained.

<Creation of carbon black dispersion>
[Examples 1 to 35, Comparative Examples 1 to 7]
According to the composition shown in Table 2, carbon black, a dispersant, an additive, and a dispersion medium are charged as a conductive material in a glass bottle, and after sufficiently mixing and dissolving or mixing, 1.25 mmφ zirconia beads are used as a medium and a paint conditioner is used. After time dispersion, each carbon black dispersion was obtained. As shown in Table 2, all of the dispersions 1 to 35 using the dispersant of the present invention had low viscosity and good storage stability. In this specification, Example 1 is a reference example.

Claims (10)

A copolymer containing a unit derived from (meth) acrylonitrile and a unit derived from one or more monomers selected from the group consisting of an active hydrogen group-containing monomer, a basic monomer, and a (meth) acrylic acid alkyl ester. Yes,
The copolymer is a dispersant containing 40 to 99% by mass of a unit derived from the (meth) acrylonitrile and having a weight average molecular weight of 5,000 to 50,000. A copolymer containing a unit derived from (meth) acrylonitrile and a unit derived from one or more monomers selected from the group consisting of an active hydrogen group-containing monomer, a basic monomer, and a (meth) acrylic acid alkyl ester. Yes,
The copolymer contains 40 to 99% by mass of a unit derived from acrylonitrile, and has a weight average molecular weight of 5,000 to 50,000.
A dispersant in which the unit derived from acrylonitrile has a cyclic structure. A copolymer containing a unit derived from acrylonitrile and a unit derived from (meth) acrylic acid.
The copolymer contains 40 to 99% by mass of a unit derived from the acrylonitrile and 1 to 25% by mass of a unit derived from (meth) acrylic acid, and has a weight average molecular weight of 5,000 to 50,000.
A dispersant in which the unit derived from acrylonitrile and the (meth) acrylic acid unit form a cyclic structure. A dispersion containing a dispersion medium, the dispersant according to any one of claims 1 to 3, and a dispersant. The dispersion according to claim 4, wherein the dispersion is a conductive material. The dispersion according to claim 4 or 5, which comprises at least one selected from the group consisting of inorganic metal salts, inorganic bases and organic bases. A resin composition containing the dispersion according to any one of claims 4 to 6 and a binder resin. The resin composition according to claim 7, further comprising an active material. An electrode including an electrode layer and a mixture layer formed from the resin composition according to claim 8. The dispersion according to claim 4, wherein the dispersion is one or more selected from the group consisting of a colorant and cellulose fibers.