Hydrogenated nitrile-based latex, manufacturing method therefor, and carbon material dispersion liquid

Abstract

The present invention relates to a hydrogenated nitrile-based latex having low residual inorganic content and low molecular weight characteristics, a method for preparing same, and a carbon material dispersion liquid comprising same, and provides a hydrogenated nitrile-based latex, a method for preparing same, and a carbon material dispersion liquid, wherein the latex comprises a hydrogenated nitrile-based copolymer satisfying equation (1): Ru+Pd+Rh < 60 ppm and equation (2): Ca+Mg+Al < 200 ppm and having a solvent replacement viscosity of 10 cps (inclusive) to 150 cps (inclusive) and a weight average molecular weight of 10,000 g / mol (inclusive) to 80,000 g / mol (exclusive).

Description

Hydrogenated nitrile latex, its manufacturing method, and carbon material dispersion

[0001] [Cross-reference with related applications]

[0002] This application claims the benefit of priority to Korean Patent Application No. 10-2024-0032865, filed March 7, 2024, and Korean Patent Application No. 10-2024-0034630, filed March 12, 2024, the entire contents of which are incorporated herein by reference.

[0003] [Technical Field]

[0004] The present invention relates to a hydrogenated nitrile latex having a low residual inorganic content and low viscosity and low molecular weight characteristics, a method for producing the same, and a carbon material dispersion.

[0005]

[0006] In general, nitrile rubber refers to a polymer manufactured by copolymerizing an ethylenically unsaturated nitrile monomer such as acrylonitrile and a conjugated diene monomer such as 1,3-butadiene, and hydrogenated nitrile rubber is manufactured through a hydrogenation reaction of nitrile rubber. It is a special rubber with excellent heat resistance, ozone resistance, chemical resistance, and oil resistance, and is widely used in various fields such as timing belts, seals, hoses, diaphragms, and rolls.

[0007] The current commercially available hydrogenated nitrile rubber is manufactured by dissolving nitrile in a solvent, reacting it with gaseous hydrogen under high temperature and pressure conditions and in the presence of a precious metal catalyst to hydrogenate the double bonds within the nitrile rubber, and then removing the catalyst and solvent. This process is somewhat complex, and the use of a high-pressure reactor and precious metal catalyst is costly. Furthermore, the use of solvents poses environmental concerns, and the requirement for using only bulk rubber.

[0008] In addition, in the case of the above process using a precious metal catalyst, an attempt was made to use as little expensive catalyst as possible due to the high cost of the catalyst, but the use of a small amount of catalyst has the problem that the hydrogenation rate is low and the molecular weight of the hydrogenated nitrile rubber produced is high, which reduces dispersibility and increases viscosity, and if the use of a large amount of catalyst increases the amount of metal residue in the final hydrogenated nitrile rubber, the viscosity increases due to the residual metal and a high cost is required to remove the residual metal.

[0009] Another method, which uses diimide to hydrogenate nitrile rubber in the latex state, offers advantages not only in safety but also in economic and environmental aspects compared to the existing process that uses hydrogen, solvents, and expensive precious metal catalysts at high pressure. However, despite these various advantages, commercialization is currently hindered by the formation of gels as a side reaction during hydrogenation. Furthermore, crosslinking occurs during and after the hydrogenation reaction and during the drying and storage stages, which negatively affects the properties of the final hydrogenated nitrile latex.

[0010] Therefore, there is a need for a hydrogenated nitrile latex having a low molecular weight, high degree of hydrogenation, and low residual metal content, and a method for producing the same.

[0011] [Prior Art Literature]

[0012] [Patent Document]

[0013] (Patent Document 1) KR 10-2021-0035088 A (March 31, 2021)

[0014]

[0015] The purpose of the present invention is to provide a hydrogenated nitrile latex comprising a hydrogenated nitrile copolymer having low residual metal content and low viscosity characteristics.

[0016] The purpose of the present invention is to provide a method for producing the hydrogenated nitrile latex.

[0017] In addition, the present invention aims to provide a carbon material dispersion comprising the hydrogenated nitrile copolymer.

[0018]

[0019] To solve the above problem, the present invention provides a hydrogenated nitrile latex, a method for producing the same, and a carbon material dispersion.

[0020] (1) The present invention provides a hydrogenated nitrile latex, which satisfies the following formulas (1) and (2), has a solvent displacement viscosity of 10 cps or more and 150 cps or less, and a weight average molecular weight of 10,000 g / mol or more and less than 80,000 g / mol, and wherein the solvent displacement viscosity is measured using a Brookfield viscometer (#63 spin, 25°C) for a solution in which the hydrogenated nitrile copolymer is dissolved in an amide dispersion medium at 16 wt%:

[0021] Equation (1): Ru+Pd+Rh < 60 ppm

[0022] Equation (2): Ca+Mg+Al < 200 ppm

[0023] In the above equations (1) and (2),

[0024] Ru, Pd, Rh, Ca, Mg, and Al are the contents of each metal ion in the hydrogenated nitrile copolymer, respectively, measured by ICP-OES (RF power 1300 W, plasma gas flow 15 l / min).

[0025] (2) The present invention provides a hydrogenated nitrile-based latex in the above (1), wherein the Ru+Pd+Rh of the formula (1) is less than 50 ppm, and the Ca+Mg+Al of the formula (2) is less than 200 ppm.

[0026] (3) The present invention provides a hydrogenated nitrile-based latex in the above (1) or (2), wherein the formula (1) Ru+Pd+Rh is less than 50 ppm and the formula (2) Ca+Mg+Al is less than 100 ppm.

[0027] (4) The present invention provides a hydrogenated nitrile-based latex having a viscosity of 10 cps or more and 100 cps or less, wherein the hydrogenated nitrile-based copolymer is in any one of the above (1) to (3).

[0028] (5) The present invention provides a hydrogenated nitrile-based latex according to any one of the above (1) to (4), wherein the hydrogenated nitrile-based copolymer has a weight average molecular weight of 15,000 g / mol or more and 55,000 g / mol or less.

[0029] (6) The present invention provides a hydrogenated nitrile-based latex in any one of the above (1) to (5), wherein the hydrogenated nitrile-based copolymer has a degree of hydrogenation of 60% or more.

[0030] (7) The present invention provides a hydrogenated nitrile latex, wherein the hydrogenated nitrile copolymer comprises an ethylenically unsaturated nitrile monomer unit and a hydrogenated conjugated diene monomer unit in any one of the above (1) to (6).

[0031] (8) The present invention provides a hydrogenated nitrile latex in (7) above, wherein the weight ratio of the ethylenically unsaturated nitrile monomer unit and the hydrogenated conjugated diene monomer unit is 1:99 to 50:50.

[0032] (9) The present invention provides a hydrogenated nitrile latex according to (7) or (8), wherein the hydrogenated nitrile copolymer further includes a conjugated diene monomer unit.

[0033] (10) The present invention provides a method for producing a hydrogenated nitrile latex according to any one of (1) to (10) above, comprising the steps of: (S1) preparing a nitrile copolymer by polymerizing a monomer mixture including a conjugated diene monomer and an ethylenically unsaturated nitrile monomer in the presence of an emulsifier; (S2) hydrogenating the nitrile copolymer to prepare a hydrogenated nitrile copolymer; and (S3) subjecting the hydrogenated nitrile copolymer to an ozone decomposition reaction, wherein the ozone decomposition reaction of the step (S3) is performed by bubbling a mixture of air and ozone through the hydrogenated nitrile copolymer, and the mixture of air and ozone contains 0.1 mol or more and less than 0.5 mol of ozone.

[0034] (11) The present invention provides a method for producing a hydrogenated nitrile-based latex, wherein the hydrogenation in step (S2) is performed in the presence of an oxidizing agent and a reducing agent in the nitrile-based copolymer in the above (10).

[0035] (12) The present invention provides a method for producing a hydrogenated nitrile latex, wherein the ozone decomposition reaction in step (S3) is performed at a temperature of 0°C to 75°C in the above (10) or (11).

[0036] (13) The present invention provides a carbon material dispersion comprising a carbon material, a dispersion medium, and a hydrogenated nitrile copolymer, wherein the hydrogenated nitrile copolymer satisfies the following formulas (1) and (2), has a solvent displacement viscosity of 10 cps or more and 150 cps or less, and a weight average molecular weight of 10,000 g / mol or more and less than 80,000 g / mol, and the solvent displacement viscosity is measured using a Brookfield viscometer (#63 spin, 25°C) for a solution in which the hydrogenated nitrile copolymer is dissolved in an amide dispersion medium at 16 wt%:

[0037] Equation (1): Ru+Pd+Rh < 60 ppm

[0038] Equation (2): Ca+Mg+Al < 200 ppm

[0039] In the above equations (1) and (2),

[0040] Ru, Pd, Rh, Ca, Mg, and Al are the contents of each metal ion in the hydrogenated nitrile copolymer, respectively, measured by ICP-OES (RF power 1300 W, plasma gas flow 15 l / min).

[0041] (14) The present invention provides a carbon material dispersion having a viscosity of 1,000 cps or more and less than 15,000 cps in the above (13).

[0042] (15) The present invention provides a carbon material dispersion in the above (13) or (14), wherein the carbon material is at least one selected from the group consisting of carbon black, Ketjen black, fullerene, graphene, carbon nanotubes, carbon black, and graphite.

[0043]

[0044] The hydrogenated nitrile latex according to the present invention has a low residual inorganic matter content and, in addition, has low viscosity, thereby exhibiting excellent dispersibility.

[0045] The method for producing a hydrogenated nitrile latex according to the present invention can produce a hydrogenated nitrile latex having a low molecular weight and low viscosity with an excellent degree of hydrogenation while having an extremely low content of residual metal by hydrogenating in the absence of a precious metal catalyst and performing an ozone decomposition reaction with a controlled ozone content.

[0046] The carbon material dispersion according to the present invention can have excellent dispersibility by including a hydrogenated nitrile copolymer having low molecular weight and low viscosity and extremely low metal residue.

[0047]

[0048] Hereinafter, the present invention will be described in more detail to help understand the present invention.

[0049]

[0050] The terms or words used in the description and claims of the present invention should not be interpreted as limited to their usual or dictionary meanings, and should be interpreted as meanings and concepts that conform to the technical idea of ​​the present invention, based on the principle that the inventor can appropriately define the concept of the term to explain his or her own invention in the best way.

[0051] Definition of Terms

[0052] In this specification, the term 'latex' may mean a polymer or copolymer polymerized by polymerization that exists in a dispersed form in water or a solvent, and as a specific example, it means a polymer or copolymer of rubber polymerized by polymerization that exists in a colloidal state dispersed in a solvent, and may also be expressed as an 'emulsion'.

[0053]

[0054] measurement method

[0055] In this specification, the content of residual metal ions in the hydrogenated nitrile copolymer was measured using an ICP-OES device at RF power of 1300 W and plasma gas flow of 15 l / min, and the detection limit was 60 ppm, so a residual metal ion content of less than 60 ppm can be interpreted as no residual metal ions. At this time, the sample for ICP-OES measurement was prepared by drying the hydrogenated nitrile copolymer latex in a vacuum oven at 60°C for 24 hours to prepare the hydrogenated nitrile copolymer in the latex, diluting 0.1 g of the hydrogenated nitrile copolymer in 15 ml of hydrofluoric acid, heat-treating by increasing the temperature from room temperature (23±5°C) to 250°C for 90 minutes, and then maintaining it for 60 minutes.

[0056] In this specification, the solution displacement viscosity of the hydrogenated nitrile copolymer is measured using a Brookfield viscometer (#63 spin, 25°C) using a dispersion solution containing 16 wt% of the hydrogenated nitrile copolymer as a sample, and the dispersion solution is a mixture of the hydrogenated nitrile copolymer and an amide dispersion medium, and the amide dispersion medium may be at least one selected from the group consisting of dimethylformamide, diethylformamide, dimethyl acetamide, and N-methyl pyrrolidone.

[0057] In this specification, the weight average molecular weight was measured using gel permeation chromatography (Waters PL-GPC220) and a Polymer Lavoratories PLgel MIX-B 300 mm long column under the following conditions.

[0058] Measurement temperature: 40℃

[0059] Flow rate: 0.3 ml / min

[0060] Injection volume: 20 μl

[0061] Standard specimen: polystyrene

[0062] In this specification, the degree of hydrogenation was measured by dissolving 10 mg of the hydrogenated nitrile copolymer before and after hydrogenation in CDCl3 to prepare a sample with a concentration of 25 mg / 1 ml, and using 500 NHz NMR (Varian). 1 It was confirmed by measuring H NMR and calculated from the ratio of peak integrals of 1,2-bond amount (4.8 ppm to 5.1 ppm) and 1,4-bond amount (5.2 ppm to 5.5 ppm) of butadiene before and after hydrogenation.

[0063]

[0064] Hydrogenated nitrile latex

[0065] The present invention provides a hydrogenated nitrile latex comprising a hydrogenated nitrile copolymer having a low residual metal content and low molecular weight and low viscosity.

[0066] The hydrogenated nitrile-based latex according to the present invention satisfies the following formulas (1) and (2), includes a hydrogenated nitrile-based copolymer having a solvent displacement viscosity of 10 cps or more and 150 cps or less, and a weight average molecular weight of 10,000 g / mol or more and less than 80,000 g / mol, and is characterized in that the solvent displacement viscosity is measured using a Brookfield viscometer (#63 spin, 25°C) for a solution in which the hydrogenated nitrile-based copolymer is dissolved in an amide-based dispersion medium at 16 wt%.

[0067] Equation (1): Ru+Pd+Rh < 60 ppm

[0068] Equation (2): Ca+Mg+Al < 200 ppm

[0069] In the above equations (1) and (2),

[0070] Ru, Pd, Rh, Ca, Mg, and Al are the contents of each metal ion in the hydrogenated nitrile copolymer, respectively, measured by ICP-OES (RF power 1300 W, plasma gas flow 15 l / min).

[0071] In addition, the above formula (1) Ru+Pd+Rh according to the present invention may be less than 60 ppm, less than 55 ppm, less than 50 ppm, less than 45 ppm, less than 40 ppm, less than 35 ppm, less than 30 ppm, less than 25 ppm, or less than 20 ppm.

[0072] In addition, the above formula (2) Ca+Mg+Al according to the present invention may be less than 200 ppm, less than 180 ppm, less than 150 ppm, less than 110 ppm, less than 100 ppm, less than 90 ppm, less than 80 ppm, less than 70 ppm, less than 60 ppm, less than 50 ppm, less than 40 ppm, less than 30 ppm, less than 20 ppm, less than 10 ppm, or less than 5 ppm.

[0073] In addition, the hydrogenated nitrile copolymer according to the present invention has a solvent displacement viscosity of 10 cps or more and 150 cps or less, and the solvent displacement viscosity is measured using a Brookfield viscometer (#63 spin, 25°C) for a solution in which the hydrogenated nitrile copolymer is dissolved in an amide dispersion medium at 16 wt%.

[0074] In addition, the hydrogenated nitrile copolymer according to the present invention may have a solvent displacement viscosity of 150 cps or less, 140 cps or less, 130 cps or less, 120 cps or less, 110 cps or less, or 100 cps or less, and may be 10 cps or more, 15 cps or more, 20 cps or more, or 30 cps or more.

[0075] In addition, the hydrogenated nitrile copolymer according to the present invention may have a solvent displacement viscosity of 10 cps or more and 100 cps or less, 20 cps or more and 150 cps or less, or 30 cps or more and 100 cps or less.

[0076] The hydrogenated nitrile copolymer according to the present invention has the solvent substitution viscosity described above, and thus, the carbon material agglomeration phenomenon of the carbon material dispersion liquid containing the hydrogenated nitrile copolymer is easily suppressed while the dispersion viscosity is low, which can be advantageous in improving the dispersibility of the carbon material dispersion liquid.

[0077] In addition, the hydrogenated nitrile copolymer according to the present invention may have a weight average molecular weight of 10,000 g / mol or more and less than 80,000 g / mol, 15,000 g / mol or more and less than 75,000 g / mol, 15,000 g / mol or more and less than 70,000 g / mol, 15,000 g / mol or more and less than 65,000 g / mol, 15,000 g / mol or more and less than 60,000 g / mol, or 15,000 g / mol or more and less than 55,000 g / mol.

[0078] In addition, the hydrogenated nitrile copolymer according to the present invention may have a degree of hydrogenation of 60% or more.

[0079] Generally, hydrogenated nitrile copolymers are manufactured through a hydrogenation reaction of nitrile copolymers. The current commercialized manufacturing process of hydrogenated nitrile copolymers involves dissolving nitrile rubber in a solvent, reacting it with gaseous hydrogen under high temperature and high pressure conditions in the presence of a noble metal catalyst to hydrogenate the double bonds in the nitrile copolymer, and then removing the used catalyst and solvent. However, there is a problem that the high cost is incurred due to the use of a high-pressure reactor and a noble metal catalyst. In addition, if a small amount of the noble metal catalyst is used to reduce the cost, the hydrogenation rate is low and the molecular weight of the hydrogenated nitrile copolymer is high, which reduces dispersibility and increases viscosity. In addition, if an appropriate amount or a large amount of the noble metal catalyst is used, the amount of metal residue in the hydrogenated nitrile copolymer is large, which increases the viscosity due to the residual metal, and a high cost is required to remove the residual metal. In addition, the production of the currently commercialized hydrogenated nitrile copolymer is performed by adding a coagulant (coagulant, AlSO4, MgSO4, CaCl2) to a polymer latex obtained by copolymerization (emulsion polymerization) of an ethylenically unsaturated nitrile monomer and a conjugated diene monomer to coagulate the polymer latex to obtain a nitrile copolymer, and then dispersing the same in a solvent to prepare a nitrile copolymer solution and hydrogenating it. Therefore, metal components (Ca, Mg, Al) derived from the coagulant may remain in the hydrogenated nitrile copolymer, which may cause an increase in viscosity.

[0080] However, since the hydrogenated nitrile copolymer according to the present invention is directly hydrogenated from a polymer latex obtained by copolymerization (emulsion polymerization) of an ethylenically unsaturated nitrile monomer and a conjugated diene monomer, no metal component derived from a coagulant remains, and therefore the amount of residual metal in the rubber is very small as defined in the above formulas (1) and (2), and since it has the solvent substitution viscosity and weight average molecular weight described above, it can have excellent dispersibility and has the advantageous effect of not having a high cost problem.

[0081]

[0082] In addition, the hydrogenated nitrile copolymer is produced by copolymerizing an ethylenically unsaturated nitrile monomer and a conjugated diene monomer, and is produced by hydrogenating the C=C double bond in the conjugated diene monomer unit of a nitrile rubber including an ethylenically unsaturated nitrile monomer unit and a conjugated diene monomer unit. Accordingly, the hydrogenated nitrile copolymer according to the present invention may include an ethylenically unsaturated nitrile monomer unit; and a hydrogenated conjugated diene monomer unit, and may further include a conjugated diene monomer unit.

[0083] Additionally, the weight ratio of the ethylenically unsaturated nitrile monomer unit and the hydrogenated conjugated diene monomer unit may be 1:99 to 50:50.

[0084] The ethylenically unsaturated nitrile monomer forming the above ethylenically unsaturated nitrile monomer unit may be at least one selected from the group consisting of acrylonitrile, methacrylonitrile, fumaronitrile, α-chloronitrile, and α-cyano ethyl acrylonitrile. As a specific example, the ethylenically unsaturated nitrile monomer may be acrylonitrile or methacrylonitrile, and more specifically, may be acrylonitrile.

[0085] The above-mentioned hydrogenated conjugated diene monomer unit and the conjugated diene monomer forming the conjugated diene monomer unit may be at least one selected from the group consisting of 1,3-butadiene, 2,3-dimethyl-1,3-butadiene, 2-ethyl-1,3-butadiene, 1,3-pentadiene, and isoprene. As a specific example, the conjugated diene monomer may be 1,3-butadiene.

[0086] In addition, according to the present invention, the hydrogenated nitrile copolymer may further include at least one of an ethylenically unsaturated acid monomer unit and an ethylenically unsaturated monomer unit, as needed.

[0087] The ethylenically unsaturated acid monomer forming the above ethylenically unsaturated acid monomer unit may be an ethylenically unsaturated monomer containing an acidic group such as a carboxyl group, a sulfonic acid group, or an acid anhydride group. As a specific example, the ethylenically unsaturated acid monomer may include at least one selected from the group consisting of ethylenically unsaturated acid monomers such as acrylic acid, methacrylic acid, itaconic acid, maleic acid, and fumaric acid; polycarboxylic acid anhydrides such as maleic anhydride and citraconic anhydride; ethylenically unsaturated sulfonic acid monomers such as styrene sulfonic acid; and ethylenically unsaturated polycarboxylic acid partial ester monomers such as monobutyl fumarate, monobutyl maleate, and mono-2-hydroxypropyl maleate. As a more specific example, the ethylenically unsaturated acid monomer may be at least one selected from the group consisting of acrylic acid, methacrylic acid, itaconic acid, maleic acid, and fumaric acid, and as a more specific example, it may be methacrylic acid. The ethylenically unsaturated acid monomer may also be used in the form of a salt, such as an alkali metal salt or an ammonium salt, during polymerization. The content of the ethylenically unsaturated acid monomer unit may be 1 wt% to 5 wt% based on the total content of the hydrogenated nitrile copolymer.

[0088] In addition, the ethylenically unsaturated monomer forming the ethylenically unsaturated monomer unit is selected from the group consisting of a hydroxyalkyl (meth)acrylate monomer having 1 to 4 carbon atoms; a vinyl aromatic monomer selected from the group consisting of styrene, aryl styrene, and vinyl naphthalene; a fluoroalkyl vinyl ether monomer such as fluoroethyl vinyl ether; an ethylenically unsaturated amide monomer selected from the group consisting of (meth)acrylamide, N-methylol (meth)acrylamide, N,N-dimethylol (meth)acrylamide, N-methoxy methyl (meth)acrylamide, and N-propoxy methyl (meth)acrylamide; a non-conjugated diene monomer such as vinyl pyridine, vinyl norbornene, dicyclopentadiene, and 1,4-hexadiene; Methyl (meth)acrylate, ethyl (meth)acrylate, butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, trifluoroethyl (meth)acrylate, tetrafluoropropyl (meth)acrylate, dibutyl maleate, dibutyl fumarate, diethyl maleate, methoxymethyl (meth)acrylate, ethoxyethyl (meth)acrylate, methoxyethoxyethyl (meth)acrylate, cyanomethyl (meth)acrylate, 2-cyanoethyl (meth)acrylate, 1-cyanopropyl (meth)acrylate, 2-ethyl-6-cyanohexyl (meth)acrylate, 3-cyanopropyl (meth)acrylate, hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, It may include at least one selected from the group consisting of ethylenically unsaturated carboxylic acid ester monomers selected from the group consisting of glycidyl (meth)acrylate, and dimethylamino ethyl (meth)acrylate. The content of the ethylenically unsaturated monomer unit may be 0.5 wt% to 5 wt% with respect to the total content of the hydrogenated nitrile copolymer.

[0089] The hydrogenated nitrile copolymer latex according to the present invention may have a solid content of 10 wt% or more and 30 wt% or less.

[0090]

[0091] The hydrogenated nitrile latex according to the present invention can be used in various fields such as timing belts, seals, hoses, diaphragms, rolls, dispersants, and electrode active material slurry compositions.

[0092]

[0093] Method for producing hydrogenated nitrile latex

[0094] The present invention provides a manufacturing method capable of obtaining a hydrogenated nitrile latex having a very small amount of metal residue, low viscosity, and low molecular weight in the absence of a precious metal catalyst.

[0095] A method for producing a hydrogenated nitrile latex according to the present invention comprises the steps of: (S1) polymerizing a monomer mixture including a conjugated diene monomer and an ethylenically unsaturated nitrile monomer in the presence of an emulsifier to produce a nitrile copolymer; (S2) hydrogenating the nitrile copolymer to produce a hydrogenated nitrile copolymer; and (S3) subjecting the hydrogenated nitrile copolymer to an ozone decomposition reaction. The ozone decomposition reaction of the step (S3) is performed by bubbling a mixture of air and ozone through the hydrogenated nitrile copolymer, and the mixture of air and ozone may contain 0.1 mol or more and less than 0.5 mol of ozone.

[0096] Here, the monomers used in the production of the nitrile copolymer are as described above.

[0097]

[0098] Hereinafter, the method for manufacturing the hydrogenated nitrile latex according to the present invention will be described in more detail step by step.

[0099]

[0100] (S1) Step

[0101] The above step (S1) is a step for producing a nitrile copolymer by copolymerizing a conjugated diene monomer and an ethylenically unsaturated nitrile monomer, and can be performed by polymerizing a monomer mixture including a conjugated diene monomer and an ethylenically unsaturated nitrile monomer in the presence of an emulsifier.

[0102] Here, the polymerization may be performed through conventional emulsion polymerization, and the emulsifier may be at least one fatty acid salt selected from the group consisting of oleic acid, rosin acid, lauric acid, myristic acid, palmitic acid, stearic acid, naphthalene sulfonic acid, and eicosanoic acid; at least one sulfonate emulsifier selected from the group consisting of sulfosuccinate emulsifiers, disulfonate emulsifiers, and linear alkylbenzene sulfonate emulsifiers, and mixtures thereof.

[0103] In addition, the polymerization can be further carried out using additives such as a polymerization initiator and a molecular weight regulator, and the polymerization initiator is an inorganic peroxide such as sodium persulfate, potassium persulfate, ammonium persulfate, potassium perphosphate, and hydrogen peroxide; an organic peroxide such as t-butyl peroxide, cumene hydroperoxide, p-menthane hydroperoxide, di-t-butyl peroxide, t-butylcumyl peroxide, acetyl peroxide, isobutyl peroxide, octanoyl peroxide, dibenzoyl peroxide, 3,5,5-trimethylhexanol peroxide, and t-butyl peroxy isobutyrate; One or more selected from the group consisting of azobis compounds such as azobisisobutyronitrile, azobis-2,4-dimethylvaleronitrile, azobiscyclohexanecarbonitrile, and azobisisobutyric acid (methyl butyrate) can be used.

[0104] In addition, the molecular weight regulator may be at least one selected from the group consisting of n-octyl mercaptan, n-dodecyl mercaptan, n-decyl mercaptan, t-dodecyl mercaptan, 2,2,4,6,6-pentamethylheptane-4-thiol, and 2,2,4,6,6,8,8-heptamethylnonane-4-thiol.

[0105] In addition, during the polymerization, additives such as activators, chelating agents, dispersants, pH regulators, deoxidizers, particle size regulators, anti-aging agents, and oxygen scavengers may be used within a range that does not deteriorate the physical properties of the rubber, as needed.

[0106] Additionally, the polymerization can be carried out at a temperature range of 10°C to 90°C or a temperature range of 10°C to 75°C.

[0107] In addition, after the polymerization, a polymerization terminator may be added to terminate the polymerization, and the polymerization terminator may be one commonly used in the art, and may include, for example, aromatic hydroxy dithiocarboxylic acids such as hydroxyl amine, N,N-diethyl hydroxylamine, hydroxy amine sulfate, diethyl hydroxy amine, hydroxy amine sulfonic acid and alkali metal ions thereof, sodium dimethyl dithiocarbamate, hydroquinone derivatives, hydroxy diethyl benzene dithiocarboxylic acid, and hydroxy dibutyl benzene dithiocarboxylic acid.

[0108] In addition, after the polymerization, the polymer can be obtained in a latex state, or a conventional post-processing process can be performed, and a nitrile copolymer can be obtained by performing one or more post-processing processes selected from, for example, coagulation, solvent removal or precipitation, and drying.

[0109] Here, the latex refers to a dispersion (emulsion) in which polymer particles are dispersed in a liquid phase.

[0110]

[0111] (S2) Step

[0112] The above step (S2) is a step for producing a hydrogenated nitrile copolymer by hydrogenating the nitrile copolymer produced above, and the hydrogenation can be performed in the presence of an oxidizing agent and a reducing agent.

[0113] The oxidizing agent may be at least one selected from the group consisting of oxygen and peroxide, the peroxide may be hydrogen peroxide, and the content of the oxidizing agent may be 1 part by weight to 100 parts by weight, 5 parts by weight to 80 parts by weight, 10 parts by weight to 70 parts by weight, 15 parts by weight to 50 parts by weight, or 20 parts by weight to 40 parts by weight, based on 100 parts by weight of the nitrile-based copolymer.

[0114] In addition, the reducing agent may be at least one selected from the group consisting of hydrazine and hydrazine hydrate, and the content of the reducing agent may be 1 part by weight to 100 parts by weight, 1 part by weight to 50 parts by weight, 2 parts by weight to 40 parts by weight, 3 parts by weight to 30 parts by weight, or 5 parts by weight to 20 parts by weight, based on 100 parts by weight of the nitrile-based copolymer.

[0115] In addition, the hydrogenation reaction may be performed at a temperature range of 30°C to 90°C or a temperature range of 40°C to 70°C, and may be performed for 6 to 20 hours or 8 to 16 hours.

[0116]

[0117] (S3) Step

[0118] The above step (S3) is a step for producing a hydrogenated nitrile latex from the hydrogenated nitrile copolymer produced above, and can be performed by subjecting the hydrogenated nitrile copolymer to an ozone decomposition reaction.

[0119] The above ozone decomposition reaction may be performed by bubbling a mixture of air and ozone over a hydrogenated nitrile copolymer to remove any remaining reducing agent and to split polymer chains to lower the molecular weight. At this time, the mixture of air and ozone may contain 0.1 mol or more and less than 0.5 mol or 0.1 mol to 0.3 mol of ozone.

[0120] Additionally, the ozone decomposition reaction may be performed at a temperature of 0°C to 75°C.

[0121]

[0122] Carbon material dispersion

[0123] The present invention provides a carbon material dispersion having excellent dispersibility.

[0124] A carbon material dispersion according to the present invention comprises a carbon material, a dispersion medium, and a hydrogenated nitrile copolymer, wherein the hydrogenated nitrile copolymer satisfies the following formulas (1) and (2), has a solvent displacement viscosity of 10 cps or more and 150 cps or less, and a weight average molecular weight of 10,000 g / mol or more and less than 80,000 g / mol, and the solvent displacement viscosity may be measured using a Brookfield viscometer (#63 spin, 25°C) for a solution in which the hydrogenated nitrile copolymer is dissolved in an amide dispersion medium at 16 wt%.

[0125] Equation (1): Ru+Pd+Rh < 60 ppm

[0126] Equation (2): Ca+Mg+Al < 200 ppm

[0127] In the above equations (1) and (2),

[0128] Ru, Pd, Rh, Ca, Mg, and Al are the contents of each metal ion in the hydrogenated nitrile copolymer, respectively, measured by ICP-OES (RF power 1300 W, plasma gas flow 15 l / min).

[0129] The specific description of the hydrogenated nitrile copolymer in the above carbon material dispersion is as described above.

[0130] In addition, the carbon material dispersion according to the present invention may have a viscosity of 1,000 cps or more and less than 15,000 cps, 2,000 cps or more and 10,000 cps or less, or 2,000 cps or more and 5,000 cps or less, in which case the carbon materials may not aggregate with each other and may have excellent dispersibility.

[0131] In addition, the carbon material according to the present invention may be at least one selected from the group consisting of carbon black, Ketjen black, fullerene, graphene, carbon nanotubes, carbon black, and graphite. The carbon material may be included in the carbon material dispersion in an amount of 1 wt% or more and 10 wt% or less, 2 wt% or more and 8 wt% or less, or 3 wt% or more and 7 wt% or less. In this case, the carbon material dispersion containing the carbon material has excellent dispersibility, so that processability is excellent and conductivity is good, so that battery performance can be excellent.

[0132] In addition, the hydrogenated nitrile copolymer may be included in the carbon material dispersion in an amount of 0.2 wt% or more and 4.0 wt% or less, 0.4 wt% or more and 3.2 wt% or less, or 0.6 wt% or more and 2.8 wt% or less. In this case, the carbon material dispersion including the hydrogenated nitrile copolymer may have excellent dispersibility, excellent processability, and good conductivity, thereby enabling excellent battery performance.

[0133] In addition, the dispersion medium may be a solvent commonly used in the relevant technical field, and for example, N-methyl-2-pyrrolidone, dimethyl sulfoxide, isopropyl alcohol, acetone, or water may be used alone or in combination. At this time, the amount of the dispersion medium used may be appropriately adjusted in consideration of the viscosity of the carbon material dispersion.

[0134]

[0135] Meanwhile, the carbon material dispersion according to the present invention may be prepared by mixing a carbon material, a hydrogenated nitrile copolymer, and a dispersion medium, wherein the mixing may be performed under temperature conditions that do not change the physical properties. For example, the mixing may be performed at a temperature of 50°C or less, or 5°C or more and 50°C or less.

[0136] The above mixing can be performed by any conventional mixing means without any particular limitation as long as the carbon material and hydrogenated nitrile copolymer can be evenly dispersed in the carbon material dispersion, and can be performed by, for example, a ball mill, a bead mill, a disc mill, a basket mill, or a high pressure homogenizer.

[0137]

[0138] Meanwhile, the carbon material dispersion according to the present invention can be used in an electrode active material slurry composition.

[0139] Example

[0140] Hereinafter, the present invention will be described in more detail by way of examples. However, the following examples are intended to illustrate the present invention and are not intended to limit the scope of the present invention solely to these examples.

[0141] Example 1

[0142] 450 g of a nitrile copolymer (NBR6240, AN 34 wt%, MV 41, LG CHEM) was placed in a 3 L reactor, 48 g of hydrazine and 130 g of hydrogen peroxide were added, and a hydrogenation reaction was performed at 40°C for 16 hours. Thereafter, an air / ozone mixture containing 0.2 mol of ozone was bubbled through the hydrogenated nitrile rubber latex using a glass tube to carry out an ozonolysis reaction, thereby producing a hydrogenated nitrile latex (solid content: 21 wt%) containing a hydrogenated nitrile copolymer.

[0143]

[0144] Example 2

[0145] A hydrogenated nitrile latex (solid content: 21 wt%) was manufactured in the same manner as in Example 1, except that the ozone decomposition reaction was performed using an air / ozone mixture containing 0.1 mol of ozone.

[0146]

[0147] Example 3

[0148] In the above Example 1, except that the ozone decomposition reaction was performed using an air / ozone mixture containing 0.3 mol of ozone, a hydrogenated nitrile latex (solid content: 21 wt%) was manufactured in the same manner as in Example 1.

[0149]

[0150] Example 4

[0151] In the above Example 1, a hydrogenated nitrile latex (solid content: 21 wt%) was manufactured in the same manner as in Example 1, except that the hydrogenation reaction was performed at 43°C and the ozone decomposition reaction was performed using an air / ozone mixture containing 0.1 mol of ozone.

[0152]

[0153] Comparative Example 1

[0154] A polymer containing 34 wt% acrylonitrile and 66 wt% 1,3-butadiene in 270 g of chlorobenzene was introduced into a high-pressure reactor. The reactor was degassed three times with pure H2 (100-200 psi) under sufficient stirring, the reactor temperature was increased to 130°C, and a solution of 3.9 g (0.076 phr) of a tris(triphenylphosphine)-rhodium(I) chloride catalyst and 0.232 g of triphenylphosphine (TPP) as a cocatalyst in 60 ml of monochlorobenzene having an oxygen content of less than 5 ppm was introduced into the reactor under hydrogen, and a hydrogenation reaction was performed to produce a hydrogenated nitrile-based latex (solid content: 21 wt%) including a hydrogenated nitrile-based copolymer. The hydrogenation reaction was carried out by raising the reactor temperature to 138°C and setting the pressure to 1200 psi (83 atm), and maintaining the temperature and hydrogen pressure inside the reactor constant throughout the entire reaction.

[0155]

[0156] Comparative Example 2

[0157] A 400 ml (48 g total solids) latex solution containing 34 wt% acrylonitrile and 66 wt% 1,3-butadiene and ion-exchanged water was added to adjust the total solids concentration to 12 wt%. The latex solution was placed in a 1 L autoclave equipped with a stirrer, and nitrogen gas was passed through it for 10 minutes to remove dissolved oxygen in the solution. Then, a hydrogenation reaction catalyst was added. The hydrogenation reaction catalyst was prepared by dissolving 75 mg of palladium acetate in 180 ml of ion-exchanged water to which nitric acid was added in a molar ratio 4 times that of palladium (Pd). After the inside of the reactor was replaced twice with hydrogen gas, the internal temperature of the reactor was increased to 50°C while the hydrogen gas was pressurized to 3 MPa, and the hydrogenation reaction was performed for 6 hours to prepare a hydrogenated nitrile latex (solids content: 21 wt%) including a hydrogenated nitrile copolymer.

[0158]

[0159] Comparative Example 3

[0160] In the above Example 1, except that the ozone decomposition reaction was performed using an air / ozone mixture containing 0.05 mol of ozone, a hydrogenated nitrile latex (solid content: 21 wt%) was manufactured in the same manner as in Example 1.

[0161]

[0162] Comparative Example 4

[0163] In the above Example 1, except that the ozone decomposition reaction was performed using an air / ozone mixture containing 0.5 mol of ozone, a hydrogenated nitrile latex (solid content: 21 wt%) was manufactured in the same manner as in Example 1.

[0164]

[0165] Comparative Example 5

[0166] In the above Example 1, except that the ozone decomposition reaction was performed using an air / ozone mixture containing 0.08 mol of ozone, a hydrogenated nitrile latex (solid content: 21 wt%) was manufactured in the same manner as in Example 1.

[0167]

[0168] Comparative Example 6

[0169] In the above Example 1, a hydrogenated nitrile latex (solid content: 21 wt%) was manufactured in the same manner as in Example 1, except that the hydrogenation reaction was performed at 37°C and the ozone decomposition reaction was performed using an air / ozone mixture containing 0.5 mol of ozone.

[0170]

[0171] Experimental Example 1

[0172] The residual metal content and viscosity of the hydrogenated nitrile copolymer in the hydrogenated nitrile latex manufactured in the above examples and comparative examples were measured, and the results are shown in Table 1 below.

[0173] (1) Residual metal content (ppm)

[0174] Each hydrogenated nitrile copolymer latex was dried in a vacuum oven at 60°C for 24 hours to prepare a hydrogenated nitrile copolymer within each latex. Thereafter, 0.1 g of the hydrogenated nitrile copolymer was diluted in 15 ml of hydrofluoric acid, heat-treated by increasing the temperature from room temperature (23±5°C) to 250°C for 90 minutes, and then maintained for 60 minutes to prepare a sample for ICP-OES measurement. The residual metal content in each hydrogenated nitrile copolymer was measured using an ICP-OES device at an RF power of 1300 W and a plasma gas flow of 15 l / min, and the detection limit for quantitative analysis of the ICP-OES device is 60 ppm.

[0175]

[0176] (2) Viscosity

[0177] Each hydrogenated nitrile latex (100 g rubber, 17 wt% solids) was added dropwise to a 5-liter sealed flask equipped with a mechanical paddle stirrer, a reflux condenser, an inlet tube for supplying N-methyl-2-pyrrolidone (NMP), and a vacuum pump while stirring. 525 L of N-methyl-2-pyrrolidone (NMP) was then added dropwise using a pump over 1 hour. Upon completion of the addition, the temperature of the sealed flask was increased to 90°C and the vacuum pump was operated to reduce the pressure to 10 torr. The pressure was reduced for 2 hours to sufficiently remove water, and a 16 wt% solvent replacement solution was prepared, which was measured using a Brookfield viscometer (#63 spin, 25°C).

[0178]

[0179] (3) Weight average molecular weight (g / mol)

[0180] Gel permeation chromatography (Waters PL-GPC220) was measured using a Polymer Lavoratories PLgel MIX-B 300 mm column under the following conditions.

[0181] Measurement temperature: 40℃

[0182] Flow rate: 0.3 ml / min

[0183] Injection volume: 20 μl

[0184] Standard specimen: polystyrene

[0185]

[0186] As shown in Table 1 above, it was confirmed that Examples 1 to 3 had residual metal contents defined by Equations (1) and (2) of less than 60 and less than 200, respectively, and had solvent displacement viscosity of 10 cps or more and 150 cps or less, and at the same time had a weight average molecular weight of 10,000 g / mol or more and 80,000 g / mol or less. Meanwhile, in Comparative Examples 1 and 2, which were prepared by coagulating a nitrile copolymer latex manufactured in a latex state through emulsion polymerization using a coagulant (AlSO4, MgSO4, CaCl2) to obtain rubber, and then adding a solvent to manufacture a latex solution and performing a hydrogenation reaction, it was confirmed that the residual metal due to the noble metal catalyst and the residual metal due to the coagulant greatly increased compared to Examples, and that the viscosity was increased due to such residual metal.

[0187] In addition, Comparative Examples 3 to 6 had a residual metal content equivalent to that of the examples, but in the case of Comparative Example 3, the ozone reaction did not occur smoothly, so the viscosity and weight average molecular weight were significantly outside the limited range, and in the case of Comparative Example 4, the viscosity was significantly reduced due to excessive polymer chain splitting.

[0188]

[0189] Meanwhile, the ICP-OES device can detect very small amounts of metal ions, so some metal components may be detected due to residual components that may be included in the raw material, residual components in the device, or contamination. Accordingly, it is expected that small amounts of Ca, Mg, and / or Al were detected in Examples 1 to 3 and Comparative Examples 3 and 4. In addition, it is interpreted that the detection limit of the ICP-OES device is 60 ppm, so Ru+Pd+Rh<60 ppm was not detected.

[0190]

[0191] Experimental Example 2

[0192] Carbon material pre-dispersion liquids containing the hydrogenated nitrile latex prepared in the above examples and comparative examples were prepared, and their viscosity was measured. The results are shown in Table 2 below.

[0193] (1) Preparation of carbon material pre-dispersion solution

[0194] In a 5-liter sealed flask equipped with a mechanical paddle stirrer, a reflux condenser, an inlet tube for supplying N-methyl-2-pyrrolidone (NMP), and a vacuum pump, 600 g of each hydrogenated nitrile latex (100 g of rubber, 17 wt% solids) was stirred while adding 525 L of N-methyl-2-pyrrolidone (NMP) dropwise using a pump over 1 hour. Upon completion of the addition, the temperature of the sealed flask was increased to 90°C and the pressure was reduced to 10 torr by operating the vacuum pump. The pressure was reduced for 2 hours to sufficiently remove water, and a solvent-displacement solution was prepared in which the hydrogenated nitrile copolymer was dissolved in the N-methyl-2-pyrrolidone at 16 wt%. The carbon material pre-dispersion solution was prepared by mixing 3.3 g of carbon nanotubes, 96 g of NMP as a dispersion medium, and 700 g of zirconia beads with a diameter of 1 mm with each of the above solvent replacement solutions (0.66 g based on hydrogenated nitrile copolymer), and then dispersing the mixture by milling it for 1 hour at 8000 rpm using a disc-type mill using Dispemat-CC (VMA-Getzmann).

[0195]

[0196] (2) Viscosity

[0197] The above carbon material dispersion liquid was measured using a viscometer (Viscometer TV-22, TOKI) at 25°C and 1 rpm.

[0198]

[0199] As shown in Table 2 above, it was confirmed that Examples 1 to 4 exhibited low viscosity characteristics with a viscosity of 3,300 cps to 8,200 cps, which was significantly reduced compared to Comparative Example 1 and Comparative Examples 3 to 6. On the other hand, in the case of Comparative Example 2, the molecular weight of the hydrogenated nitrile copolymer was too high, so that dispersion did not occur properly during the preparation of the carbon material pre-dispersion solution, making it impossible to measure the viscosity.

[0200] In addition, in the case of Comparative Example 4, the viscosity and molecular weight of the hydrogenated nitrile copolymer were low, so the agglomeration of the carbon material was not suppressed during the production of the carbon material pre-dispersion solution, and thus dispersion was not smooth, so it is predicted that the dispersion viscosity was significantly worse than in the example.

Claims

1. A hydrogenated nitrile-based latex comprising a hydrogenated nitrile-based copolymer satisfying the following formulas (1) and (2), having a solvent displacement viscosity of 10 cps or more and 150 cps or less, and a weight average molecular weight of 10,000 g / mol or more and less than 80,000 g / mol, wherein the solvent displacement viscosity is measured using a Brookfield viscometer (#63 spin, 25°C) for a solution in which the hydrogenated nitrile-based copolymer is dissolved at 16 wt% in an amide-based dispersion medium: Equation (1): Ru+Pd+Rh < 60 ppm Equation (2): Ca+Mg+Al < 200 ppm In the above equations (1) and (2), Ru, Pd, Rh, Ca, Mg, and Al are the contents of each metal ion in the hydrogenated nitrile copolymer, respectively, measured by ICP-OES (RF power 1300 W, plasma gas flow 15 l / min).

2. In paragraph 1, Hydrogenated nitrile latex, wherein the Ru+Pd+Rh of the above formula (1) is less than 50 ppm, and the Ca+Mg+Al of the formula (2) is less than 200 ppm.

3. In paragraph 1, Hydrogenated nitrile latex, wherein the Ru+Pd+Rh of the above formula (1) is less than 50 ppm, and the Ca+Mg+Al of the formula (2) is less than 100 ppm.

4. In paragraph 1, The above hydrogenated nitrile copolymer is a hydrogenated nitrile latex having a solvent displacement viscosity of 10 cps or more and 100 cps or less.

5. In paragraph 1, The above hydrogenated nitrile copolymer is a hydrogenated nitrile latex having a weight average molecular weight of 15,000 g / mol or more and 55,000 g / mol or less.

6. In paragraph 1, The above hydrogenated nitrile copolymer is a hydrogenated nitrile latex having a degree of hydrogenation of 60% or more.

7. In paragraph 1, The hydrogenated nitrile copolymer comprises an ethylenically unsaturated nitrile monomer unit; and a hydrogenated conjugated diene monomer unit. A hydrogenated nitrile latex.

8. In paragraph 7, A hydrogenated nitrile latex, wherein the weight ratio of the ethylenically unsaturated nitrile monomer unit and the hydrogenated conjugated diene monomer unit is 1:99 to 50:

50.

9. In paragraph 7, The hydrogenated nitrile-based copolymer is a hydrogenated nitrile-based latex that further includes a conjugated diene-based monomer unit.

10. A step (S1) of producing a nitrile copolymer by polymerizing a monomer mixture including a conjugated diene monomer and an ethylenically unsaturated nitrile monomer in the presence of an emulsifier; A step (S2) of hydrogenating the above nitrile copolymer to produce a hydrogenated nitrile copolymer; and It includes a step (S3) of subjecting the hydrogenated nitrile copolymer to ozone decomposition, The ozone decomposition reaction in the above step (S3) is performed by bubbling a mixture of air and ozone through the hydrogenated nitrile copolymer, A method for producing a hydrogenated nitrile latex comprising a hydrogenated nitrile copolymer, wherein the air and ozone mixture contains 0.1 mol or more and less than 0.5 mol of ozone.

11. In paragraph 10, A method for producing a hydrogenated nitrile latex, wherein the hydrogenation in the above step (S2) is performed in the presence of an oxidizing agent and a reducing agent.

12. In paragraph 10, A method for producing hydrogenated nitrile latex, wherein the ozone decomposition reaction of the above step (S3) is performed at a temperature of 0°C to 75°C.

13. Containing carbon material, dispersion medium and hydrogenated nitrile copolymer, The above hydrogenated nitrile copolymer satisfies the following formulas (1) and (2), has a solvent displacement viscosity of 10 cps or more and 150 cps or less, and a weight average molecular weight of 10,000 g / mol or more and less than 80,000 g / mol, and the solvent displacement viscosity is a carbon material dispersion measured with a Brookfield viscometer (#63 spin, 25°C) for a solution in which the hydrogenated nitrile copolymer is dissolved at 16 wt% in an amide dispersion medium: Equation (1): Ru+Pd+Rh < 60 ppm Equation (2): Ca+Mg+Al < 200 ppm In the above equations (1) and (2), Ru, Pd, Rh, Ca, Mg, and Al are the contents of each metal ion in the hydrogenated nitrile copolymer, respectively, measured by ICP-OES (RF power 1300 W, plasma gas flow 15 l / min).

14. In paragraph 13, A carbon material dispersion having a viscosity of 1000 cps or more and less than 15,000 cps.

15. In paragraph 13, A carbon material dispersion liquid wherein the above carbon material is at least one selected from the group consisting of carbon black, Ketjen black, fullerene, graphene, carbon nanotubes, carbon black, and graphite.