WO2023173807A1

WO2023173807A1 - Antioxidant conductive copper paste, and preparation method therefor and use thereof

Info

Publication number: WO2023173807A1
Application number: PCT/CN2022/135155
Authority: WO
Inventors: 李健; 何博; 董鑫; 杨泽君; 李鹏; 徐希翔
Original assignee: 西安隆基乐叶光伏科技有限公司
Priority date: 2022-03-17
Filing date: 2022-11-29
Publication date: 2023-09-21
Also published as: CN114664476A; WO2023173807A9

Abstract

An antioxidant conductive copper paste, and a preparation method therefor and the use thereof. The antioxidant conductive copper paste contains a compound containing a thiocarbamate structural unit, which compound is used as a cross-linking agent. At the curing temperature, thiol/thiophenol in the cross-linking agent is released, and the mercapto groups of the thiol/thiophenol are complexed with copper so as to be adsorbed onto the surface of a copper powder, such that the reaction of an oxide with the copper is blocked; moreover, the thiol/thiophenol also has reducibility and can preferentially react with an oxide or reduce oxidized copper, such that an excellent anti-oxidation effect can be achieved; in addition, since at the curing temperature, the thiol/thiophenol in the cross-linking agent is released, and the mercapto groups of the thiol/thiophenol is complexed with copper so as to be adsorbed onto the surface of the copper powder, the reaction of an oxide with copper is blocked; furthermore, the thiol/thiophenol also has reducibility and can preferentially react with an oxide or reduce oxidized copper, and therefore an excellent anti-oxidation effect can be achieved.

Description

Anti-oxidation conductive copper slurry, preparation method and application

This application claims priority to the Chinese patent application filed with the China Patent Office on March 17, 2022, with application number 202210263197.2 and titled "Antioxidation Conductive Copper Slurry, Preparation Method and Application", the entire content of which is incorporated by reference. in this application.

Technical field

The present application relates to the field of battery technology, and in particular to an anti-oxidation conductive copper slurry, a preparation method and its application.

Background technique

Silver paste and other precious metal pastes have been widely used in semiconductors, electronics, automobiles, new energy and other fields because of their excellent electrical conductivity. However, silver and other precious metal pastes are expensive and the silver paste migrates during use. This phenomenon has prompted people to gradually turn to research on using base metals instead of precious metals to prepare conductive pastes.

The electrical conductivity of copper is second only to silver, has no migration phenomenon, and is cheap. Therefore, it has gradually attracted people's attention in the development of conductive paste technology. However, copper is easily oxidized in the air, and its long-term stability faces challenges.

Contents of the invention

In the development of conductive copper pastes, finding and overcoming the oxidation of copper has always been the focus of research. The copper slurry described in this application uses compounds with thiocarbamate structural units and uses them as cross-linking agents. The thiols/thiophenols are released at the curing temperature, thus exerting their reducing properties. It protects copper powder from oxidation, achieves high conductivity, and can be quickly cured at low temperatures. It has stable conductivity in air atmosphere, and shows excellent performance in high-temperature oxidation experiments (200°C, 60min). of antioxidant properties.

The specific technical solutions for this application are as follows:

An antioxidant conductive copper slurry includes a compound having a thiocarbamate structural unit.

Optionally, in the anti-oxidation conductive copper slurry, the compound having a thiocarbamate structural unit is obtained by reacting thiol or thiophenol with a polyisocyanate compound.

Optionally, in the anti-oxidation conductive copper slurry, the thiol or thiol phenol is an aliphatic thiol compound with a carbon number of 1-30 and/or an aromatic sulfur compound with a carbon number of 2-30. Phenolic compounds.

Optionally, in the anti-oxidation conductive copper slurry, the polyisocyanate compound is selected from the group consisting of isocyanate, terephthalic diisocyanate, 1,3-diisocyanatotoluene, and 1,6-hexamethylene diisocyanate. , 3,3'-dimethyl-4,4'-biphenyl diisocyanate, diphenylmethane-4,4'-diisocyanate, isophorone diisocyanate, trimethylhexamethylene diisocyanate, Metaxylylene diisocyanate, o-xylylene diisocyanate, 2,6-diisocyanate toluene, 2,4-diisocyanate toluene, 2,5-diisocyanate toluene, 1,4-cyclohexyl diisocyanate, 4 ,4-diisocyanate dicyclohexylmethane, 1,4-cyclohexanedimethyldiisocyanate, trimethylhexanediisocyanate, tetramethylxylylenediisocyanate, L-lysine diisocyanate, L- One or more of lysine triisocyanate and triphenylmethane triisocyanate.

Optionally, in the anti-oxidation conductive copper slurry, the compound having a thiocarbamate structural unit is 1-10 in terms of mass percentage in the anti-oxidation conductive copper slurry. %, preferably 2-7%.

Optionally, in the anti-oxidation conductive copper slurry, the anti-oxidation conductive copper slurry further includes copper powder, resin, accelerator, auxiliary agent and conductive enhancement filler.

Optionally, in the anti-oxidation conductive copper slurry, the particle size D50 of the copper powder is 0.1-10 μm. Preferably, the shape of the copper powder is flake, spherical and/or dendritic.

Optionally, in the anti-oxidation conductive copper slurry, the resin is selected from one or more of epoxy resin, polyamide resin, saturated polyester resin, polyurethane resin, acrylic resin and silicone resin. .

Optionally, in the anti-oxidation conductive copper slurry, the accelerator is selected from one of organic amines, imidazoles, boron trifluoride complexes, organic tin compounds and transition metal complexes. Or two or more.

Optionally, in the anti-oxidation conductive copper slurry, the auxiliary agent is selected from one or more of a dispersant, a stabilizer, a thixotropic agent and a coupling agent.

Optionally, in the anti-oxidation conductive copper slurry, the conductive enhancing filler is selected from nano or sub-micron carbon black, graphene, carbon nanotubes, nickel powder, tin powder, indium powder, silver powder and aluminum. One or more than two kinds of powders.

Optionally, in the anti-oxidation conductive copper slurry, the anti-oxidation conductive copper slurry also contains a solvent. Preferably, the solvent is selected from the group consisting of hydroxyl-containing compounds with a carbon number of 2-16, carbon atoms It is one or more of an ether group-containing compound with 2 to 18 carbon atoms, a carbonyl group-containing compound with 3 to 12 carbon atoms, and an ester group-containing compound with 2 to 16 carbon atoms.

Optionally, in the anti-oxidation conductive copper slurry, the copper powder is 75-85% and the resin is 3-11% in terms of mass percentage in the anti-oxidation conductive copper slurry, The accelerator is 0.05-0.5%, the auxiliary is 0.05-0.5%, the conductive reinforcing filler is 0.1-1%, and the solvent is 2-5%.

A method for preparing anti-oxidation conductive copper slurry, including:

Mix a resin, a solvent, a compound having a thiocarbamate structural unit, an accelerator and an auxiliary agent to obtain a first mixture;

Mix copper powder and conductive reinforcing filler to obtain a second mixture;

The first mixture and the second mixture are mixed to obtain an oxidation-resistant conductive copper slurry.

Optionally, in the method, the first mixture and the second mixture are mixed and then subjected to primary dispersion and secondary dispersion to obtain the anti-oxidation conductive copper slurry.

Optionally, in the method, the viscosity of the conductive copper slurry at room temperature is 150-350 Pa·s.

Optionally, in the method, the resin, compounds having thiocarbamate structural units, accelerators, auxiliaries, copper powder and conductive reinforcing fillers are in the anti-oxidation conductive copper slurry. raw material.

An electrode comprising the anti-oxidation conductive copper slurry or the anti-oxidation conductive copper slurry prepared by the method.

A battery including the electrode.

The embodiments of this application include the following advantages:

The copper slurry described in this application contains a compound with a thiocarbamate structural unit and uses it as a cross-linking agent. At the curing temperature, the thiol/thiol in the cross-linking agent is released, The sulfhydryl groups of thiols/thiols are complexed with copper and adsorbed on the surface of copper powder, blocking the reaction between oxides and copper. At the same time, thiols/thiophenols are also reducing and can react with oxides preferentially, or will already Oxidized copper is reduced, thereby achieving excellent antioxidant effects.

In addition, since compounds with thiocarbamate structural units are obtained by combining thiols/thiophenols with polyisocyanates, thiols/thiophenols cannot exert their antioxidant properties and will not react with epoxy resins. As a result, the slurry is very stable at storage temperature (room temperature), and the viscosity will not change significantly.

Specific embodiments

This application will be described in detail below. Although specific embodiments of the present application are shown, it should be understood that the present application may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided to provide a thorough understanding of the present application, and to fully convey the scope of the present application to those skilled in the art.

It should be noted that certain words are used in the description and claims to refer to specific components. Those skilled in the art will understand that skilled persons may use different names to refer to the same component. This description and the claims do not use difference in nouns as a way to distinguish components, but rather use differences in functions of the components as a criterion for differentiation. If the words "include" or "including" mentioned throughout the description and claims are open-ended terms, they should be interpreted as "including but not limited to." The following descriptions of the description are preferred embodiments for implementing the present application. However, the descriptions are for the purpose of general principles of the description and are not intended to limit the scope of the present application. The scope of protection of this application shall be determined by the appended claims.

The present application provides the use of compounds having thiocarbamate structural units as cross-linking agents.

This application also provides the use of compounds having thiocarbamate structural units in anti-oxidation conductive copper slurries.

In some embodiments, the compound having a thiocarbamate structural unit is obtained by reacting thiol or thiophenol with a polyisocyanate compound. In some embodiments, the thiol or thiol is an aliphatic thiol compound having 1-30 carbon atoms and/or an aromatic thiol compound having 2-30 carbon atoms. In some embodiments, the polyisocyanate compound is selected from the group consisting of isocyanate, p-phenylene diisocyanate, 1,3-diisocyanatotoluene, 1,6-hexamethylene diisocyanate, 3,3'-dimethyl -4,4'-Biphenyl diisocyanate, diphenylmethane-4,4'-diisocyanate, isophorone diisocyanate, trimethylhexamethylene diisocyanate, m-xylylene diisocyanate, o- Xylylene diisocyanate, 2,6-diisocyanate toluene, 2,4-diisocyanate toluene, 2,5-diisocyanate toluene, 1,4-cyclohexyl diisocyanate, 4,4-diisocyanate dicyclohexylmethane , 1,4-cyclohexane dimethyl diisocyanate, trimethylhexane diisocyanate, tetramethylxylylene diisocyanate, L-lysine diisocyanate, L-lysine triisocyanate and triphenyl One or more than two kinds of methane triisocyanate.

For example, the mercaptan can be n-propyl mercaptan, n-butyl mercaptan, n-pentyl mercaptan, n-hexyl mercaptan, n-heptyl mercaptan, n-octyl mercaptan, n-nonyl mercaptan, n-decyl mercaptan, n-11 mercaptan Mercaptan, n-dodecyl mercaptan, isobutyl mercaptan, isopentyl mercaptan, isooctyl mercaptan, sec-butyl mercaptan or sec-octyl mercaptan, cyclopentyl mercaptan, cyclohexyl mercaptan, 2-methyltetrahydrofuran- 3-thiol, 2-thiophenethiol, benzylthiol, 2-phenylethylthiol, etc.;

The thiophenol can be thiophenol, 2-methylthiophenol, 3-methylthiophenol, 4-methylthiophenol, 4-fluorothiophenol, 2-naphthylthiophenol, 5-mercapto -1-Methyltetrazole, 3-mercapto-4-methyl-1,2,4-triazole, 2-mercapto-1-methylimidazole, 2-mercaptothiazoline, 2-mercaptopyridine, 2 -Mercaptobenzimidazole, 2-mercaptobenzothiazole, 2-mercaptobenzoxazole, 2-mercaptobenzoselenazole, 5-fluoro-2-mercaptobenzothiazole, etc.

The present application provides an oxidation-resistant conductive copper slurry, which contains a compound having a thiocarbamate structural unit. In some embodiments, the compound having a thiocarbamate structural unit is obtained by reacting thiol or thiophenol with a polyisocyanate compound. In some embodiments, the compound having a thiocarbamate structural unit serves as a cross-linking agent.

The thiol/thiol refers to an organic compound containing a -SH structure. If the -SH structure is directly connected to an aliphatic alkane, it is a thiol. If the -SH structure is directly connected to an aromatic hydrocarbon, it is a thiol. thiophenol.

The polyisocyanate compound refers to an organic compound containing at least two -N=C=O structures.

The antioxidant conductive copper slurry described in this application contains compounds with thiocarbamate structural units, and the compounds with thiocarbamate structural units are formed by mercaptan or thiophenol and polyisocyanate. The anti-oxidation conductive copper slurry is obtained by the reaction of compounds. At the curing temperature, mercaptans or thiophenols are released, and the sulfhydryl groups of the mercaptan or thiophenol molecules are complexed with copper to be adsorbed on the surface of the copper powder, blocking It prevents oxides from reacting with copper. At the same time, thiols/thiophenols also have reducing properties and can react preferentially with oxides or reduce oxidized copper. Therefore, by adding thiols/thiophenols to the conductive copper slurry, Compounds can achieve excellent antioxidant effects.

However, since mercaptans/thiophenols contain active hydrogen, they can quickly react with epoxy resins at room temperature, thereby reducing the curing performance of the resin system and shortening the application period of the conductive slurry. This results in poor stability of the slurry and is difficult to produce on a large scale, and a compound with a thiocarbamate structural unit is generated by reacting a thiol/thiophenol compound with a polyisocyanate compound, which has a thiocarbamate structure. The compound of the unit is obtained by reacting thiol or thiol with a polyisocyanate compound. At the curing temperature of the antioxidant conductive copper slurry, the thiol or thiol is released, and the thiol or thiol molecules The thiol group complexes with copper and is adsorbed on the surface of copper powder, blocking the reaction between oxide and copper. At the same time, thiol/thiol also has reducing properties and can react with oxides preferentially or reduce oxidized copper to avoid By solving the above problems, the slurry has the advantages of being stable at room temperature and having a long pot life, making it suitable for large-scale production.

In some embodiments, the thiol or thiol is an aliphatic thiol compound having 1-30 carbon atoms and/or an aromatic thiol compound having 2-30 carbon atoms.

This application does not impose any restrictions on the specific types of aliphatic thiol compounds with 1 to 30 carbon atoms and aromatic thiol phenol compounds with 2 to 30 carbon atoms. They can be selected according to the needs of the art, such as the number of carbon atoms. The aliphatic thiol compound with a value of 1-30 can be n-propyl mercaptan, n-butyl mercaptan, n-pentyl mercaptan, n-hexyl mercaptan, n-heptyl mercaptan, n-octyl mercaptan, n-nonyl mercaptan, n-decyl mercaptan , n-undecanethiol, n-dodecanethiol, isobutylthiol, isopentylthiol, isooctylthiol, sec-butylthiol or sec-octylthiol, cyclopentylthiol, cyclohexanethiol, 2- Methyltetrahydrofuran-3-thiol, 2-thiophenethiol, benzylthiol, 2-phenylethylthiol, etc., the aromatic thiophenol compound with a carbon number of 2-30 can be benzenethiophenol, 2- Methylthiophenol, 3-methylthiophenol, 4-methylthiophenol, 4-fluorothiophenol, 2-naphthylthiophenol, 5-mercapto-1-methyltetrazole, 3-mercapto -4-Methyl-1,2,4-triazole, 2-mercapto-1-methylimidazole, 2-mercaptothiazoline, 2-mercaptopyridine, 2-mercaptobenzimidazole, 2-mercaptobenzothiazole , 2-mercaptobenzoxazole, 2-mercaptobenzoselenazole, 5-fluoro-2-mercaptobenzothiazole, etc.

In some embodiments, the polyisocyanate compound is selected from the group consisting of isocyanate, p-phenylene diisocyanate, 1,3-diisocyanatotoluene, 1,6-hexamethylene diisocyanate, 3,3'-dimethyl -4,4'-Biphenyl diisocyanate, diphenylmethane-4,4'-diisocyanate, isophorone diisocyanate, trimethylhexamethylene diisocyanate, m-xylylene diisocyanate, o- Xylylene diisocyanate, 2,6-diisocyanate toluene, 2,4-diisocyanate toluene, 2,5-diisocyanate toluene, 1,4-cyclohexyl diisocyanate, 4,4-diisocyanate dicyclohexylmethane , 1,4-cyclohexane dimethyl diisocyanate, trimethylhexane diisocyanate, tetramethylxylylene diisocyanate, L-lysine diisocyanate, L-lysine triisocyanate and triphenyl One or two or more of the methane triisocyanates may be, for example, one, two, three, four or five or more of them.

In some embodiments, the compound having a thiocarbamate structural unit is 1-10%, preferably 2-7%, in terms of mass percentage in the anti-oxidation conductive copper slurry.

For example, in terms of mass percentage in the anti-oxidation conductive copper slurry, the compound having a thiocarbamate structural unit may be 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, etc.

In some embodiments, the antioxidant conductive copper slurry also contains copper powder, resin, accelerator, auxiliary agent and conductive enhancement filler. Preferably, the particle size D50 of the copper powder is 0.1-10 μm, and further preferably , the shape of the copper powder is flake, spherical and/or dendritic.

The copper powder plays a conductive role, and the copper particles contact each other to form a charge transfer path. The resin forms a skeleton. After curing, the resin molecules are connected to each other, so that between the copper powder and between the copper powder and the matrix Form close contact; the conductive enhancement filler fills the gaps between copper powders (carbon black), enhances the contact between copper powders and the matrix (indium powder), and increases the conductivity of the copper slurry (silver powder) , the auxiliary agent is at least one of a dispersant, a stabilizer, a thixotropic agent and a coupling agent, wherein the dispersant acts to reduce the surface tension of the resin system so that the solid and liquid phases form a uniform mixture; the stabilizer acts as To form electrostatic repulsion between copper powders, thereby slowing down the settling of copper powder in the slurry; the thixotropic agent provides hydrogen bonding force to slow down the fluidity of the slurry when it is static, and during operation (such as wire mesh Printing) and other fluid dynamics, the hydrogen bonds are broken, the fluidity is increased, and it has a good molding process; the coupling agent enhances the bonding force between the cured slurry and the matrix (such as silicon wafer), thereby reducing the contact resistance. The accelerator is at least one of organic amines, imidazoles, boron trifluoride complexes, organic tin compounds and transition metal complexes, which catalyzes the curing reaction, lowers the curing temperature and shortens the curing time. role.

For example, the particle size D50 of the copper powder may be 0.1 μm, 0.5 μm, 1 μm, 2 μm, 3 μm, 4 μm, 5 μm, 6 μm, 7 μm, 8 μm, 9 μm, 10 μm, etc.

In some embodiments, the resin is selected from one or more of epoxy resin, polyamide resin, saturated polyester resin, polyurethane resin, acrylic resin and silicone resin. For example, it can be one or more of them. Two, three, four or more than five types.

In some embodiments, the accelerator is selected from one or more of organic amines, imidazoles, boron trifluoride complexes, organotin complexes and transition metal complexes, for example, it can be one of the following One, two, three, four or more types of organic amines, imidazoles, boron trifluoride complexes, organotin complexes and transition metal complexes, this application Without any limitation, it can be selected according to needs. For example, the organic amines can be tripropylamine or triethanolamine, etc.; the imidazoles can be 2-methylimidazole, 2-methyl-4-ethylimidazole, etc.; The boron trifluoride complexes can be boron trifluoride ethylamine complex; the organic tin compounds can be stannous isooctanoate, dibutyltin dilaurate, etc.; the transition metal complexes can be For nickel acetylacetonate, cobalt acetylacetonate, etc.

In some embodiments, the auxiliary agent is selected from one or more of dispersants, stabilizers, thixotropic agents and coupling agents. For example, it can be one, two, three or four of them. .

This application does not impose any restrictions on the specific types of dispersants, stabilizers, thixotropic agents and coupling agents. They are all commonly used materials in this field. For example, the dispersant can be oleic acid;

The stabilizer can be phosphite;

The thixotropic agent can be polyamide wax;

The coupling agent may be isobutyltriethoxysilane.

In some embodiments, the conductive enhancing filler is selected from one or more of nano or sub-micron carbon black, graphene, carbon nanotubes, nickel powder, tin powder, indium powder, silver powder and aluminum powder. , for example, it can be one, two, three, four or more than five of them.

In some embodiments, the antioxidant conductive copper slurry also contains a solvent. Preferably, the solvent is selected from a hydroxyl-containing compound with a carbon number of 2-16 and an ether group-containing compound with a carbon number of 2-18. , one or more of a carbonyl group-containing compound with a carbon number of 3-12 and an ester group-containing compound with a carbon number of 2-16.

The solvent is to disperse the above other components in the solvent to form a slurry with a certain viscosity. For the hydroxyl-containing compound with a carbon number of 2-16 and the ether group-containing compound with a carbon number of 2-18 in the above solvent , the specific types of carbonyl-containing compounds with carbon atoms of 3-12 and ester-containing compounds with carbon atoms of 2-16 are not limited in this application, and they can be selected according to needs. For example, carbon atoms of 2 The -16 hydroxyl-containing compound can be α-terpineol; the ether group-containing compound with 2-18 carbon atoms can be ethylene glycol monomethyl ether or propylene glycol phenyl ether; the carbonyl-containing compound with 3-12 carbon atoms The compound can be dipropyl ketone; the ester group-containing compound with a carbon number of 2-16 can be butyl acetate or diethylene glycol butyl ether acetate.

In some embodiments, in terms of mass percentage in the anti-oxidation conductive copper slurry, the copper powder is 75-85%, the resin is 3-11%, and the accelerator is 0.05-0.5% , the additive is 0.05-0.5%, the conductive reinforcing filler is 0.1-1%, and the solvent is 2-5%.

In some embodiments, the oxidation-resistant conductive copper slurry includes compounds having thiocarbamate structural units. In some embodiments, the compound having a thiocarbamate structural unit is obtained by reacting thiol or thiophenol with a polyisocyanate compound.

In some embodiments, the oxidation-resistant conductive copper slurry includes compounds having thiocarbamate structural units. In some embodiments, the compound having a thiocarbamate structural unit is obtained by reacting thiol or thiophenol with a polyisocyanate compound. In some embodiments, the thiol or thiol is an aliphatic thiol compound having 1-30 carbon atoms and/or an aromatic thiol compound having 2-30 carbon atoms. In some embodiments, the polyisocyanate compound is selected from the group consisting of isocyanate, p-phenylene diisocyanate, 1,3-diisocyanatotoluene, 1,6-hexamethylene diisocyanate, 3,3'-dimethyl -4,4'-Biphenyl diisocyanate, diphenylmethane-4,4'-diisocyanate, isophorone diisocyanate, trimethylhexamethylene diisocyanate, m-xylylene diisocyanate, o- Xylylene diisocyanate, 2,6-diisocyanate toluene, 2,4-diisocyanate toluene, 2,5-diisocyanate toluene, 1,4-cyclohexyl diisocyanate, 4,4-diisocyanate dicyclohexylmethane , 1,4-cyclohexane dimethyl diisocyanate, trimethylhexane diisocyanate, tetramethylxylylene diisocyanate, L-lysine diisocyanate, L-lysine triisocyanate and triphenyl One or more than two kinds of methane triisocyanate.

In some embodiments, the oxidation-resistant conductive copper slurry includes compounds having thiocarbamate structural units. In some embodiments, the compound having a thiocarbamate structural unit is obtained by reacting thiol or thiophenol with a polyisocyanate compound. In some embodiments, the thiol or thiol is an aliphatic thiol compound having 1-30 carbon atoms and/or an aromatic thiol compound having 2-30 carbon atoms. In some embodiments, the polyisocyanate compound is selected from the group consisting of isocyanate, p-phenylene diisocyanate, 1,3-diisocyanatotoluene, 1,6-hexamethylene diisocyanate, 3,3'-dimethyl -4,4'-Biphenyl diisocyanate, diphenylmethane-4,4'-diisocyanate, isophorone diisocyanate, trimethylhexamethylene diisocyanate, m-xylylene diisocyanate, o- Xylylene diisocyanate, 2,6-diisocyanate toluene, 2,4-diisocyanate toluene, 2,5-diisocyanate toluene, 1,4-cyclohexyl diisocyanate, 4,4-diisocyanate dicyclohexylmethane , 1,4-cyclohexane dimethyl diisocyanate, trimethylhexane diisocyanate, tetramethylxylylene diisocyanate, L-lysine diisocyanate, L-lysine triisocyanate and triphenyl One or more than two kinds of methane triisocyanate. In some embodiments, the compound having a thiocarbamate structural unit is 1-10%, preferably 2-7%, in terms of mass percentage in the anti-oxidation conductive copper slurry. In some embodiments, the antioxidant conductive copper slurry further includes copper powder, resin, accelerator, auxiliary agent and conductive enhancement filler. In some embodiments, the particle size D50 of the copper powder is 0.1-10 μm. Preferably, the shape of the copper powder is flake, spherical and/or dendritic. In some embodiments, the resin is selected from one or more of epoxy resin, polyamide resin, saturated polyester resin, polyurethane resin, acrylic resin and silicone resin. In some embodiments, the accelerator is selected from one or more than two types of organic amines, imidazoles, boron trifluoride complexes, organotin complexes and transition metal complexes. In some embodiments, the auxiliary agent is selected from one or more of dispersants, stabilizers, thixotropic agents and coupling agents. In some embodiments, the conductive enhancing filler is selected from one of nanometer or sub-micron carbon black, graphene, carbon nanotubes, metal nickel powder, metal tin powder, metal indium powder, metal silver powder and metal aluminum powder. One or more species. In some embodiments, the antioxidant conductive copper slurry also contains a solvent. Preferably, the solvent is selected from a hydroxyl-containing compound with a carbon number of 2-16 and an ether group-containing compound with a carbon number of 2-18. , one or more of a carbonyl group-containing compound with a carbon number of 3-12 and an ester group-containing compound with a carbon number of 2-16. In some embodiments, in terms of mass percentage in the anti-oxidation conductive copper slurry, the copper powder is 75-85%, the resin is 3-11%, and the accelerator is 0.05-0.5% , the additive is 0.05-0.5%, the conductive reinforcing filler is 0.1-1%, and the solvent is 2-5%.

The antioxidant conductive copper slurry described in the present application has excellent oxidation resistance and good stability because it contains compounds with thiocarbamate structural units.

This application provides a method for preparing oxidation-resistant conductive copper slurry, which includes:

Mixing resin, a compound having a thiocarbamate structural unit, an accelerator and an auxiliary agent to obtain a first mixture;

Mix copper powder and conductive reinforcing filler to obtain a second mixture;

For the synthesis of compounds having thiocarbamate structural units, they are synthesized by conventional methods in the art, for example, by reacting thiols or thiophenols with polyisocyanate compounds.

In some embodiments, the first mixture and the second mixture are mixed and then subjected to primary dispersion and secondary dispersion to obtain the anti-oxidation conductive copper slurry.

In some embodiments, the conductive copper slurry has a viscosity of 150-350 Pa·s at room temperature.

In some embodiments, the resin, compounds having thiocarbamate structural units, accelerators, auxiliaries, copper powder and conductive reinforcing fillers are raw materials in the above-mentioned antioxidant conductive copper slurry.

The present application provides an electrode, which contains the above-mentioned anti-oxidation conductive copper slurry or the above-mentioned anti-oxidation conductive copper slurry prepared by the above-mentioned method.

The present application provides a battery, which includes the electrode described above.

The antioxidant conductive copper slurry described in the present application contains a compound with a thiocarbamate structural unit. The compound with a thiocarbamate structural unit is formed by thiol or thiophenol and a polyisocyanate compound. The reaction results in the release of thiol or thiol phenol at the curing temperature of the anti-oxidation conductive copper slurry, and the mercapto group of the thiol or thiol phenol molecule complexes with the copper and is adsorbed on the surface of the copper powder, blocking the oxides. React with copper, and at the same time, thiol/thiol also has reducing properties, and can react preferentially with oxides, or reduce oxidized copper, so that the anti-oxidation conductive copper slurry has a high conductivity effect, and at low temperatures It solidifies quickly and has stable conductivity in air atmosphere. After being placed at room temperature for 6 months, its conductivity has almost no change. And after the anti-oxidation conductive copper slurry is oxidized in air at 200°C for 60 minutes, its conductivity Although the conductivity decreases, it still has good conductivity.

Example

This application provides a general and/or specific description of the materials and test methods used in the test. In the following examples, if there are no other special instructions, % means wt%, that is, weight percentage. If the manufacturer of the reagents or instruments used is not indicated, they are all conventional reagent products that can be purchased commercially.

Example 1

(1) Pre-cleaning of copper powder: Prepare 100 mL of 10 wt% formic acid in absolute ethanol, and weigh the flake copper powder with a particle size of D50 = 1 μm and the spherical copper powder with a particle size of D50 = 0.5 μm according to a 4:1 mass ratio. A total of 100g was added to the formic acid solution for ultrasonic cleaning for 15 minutes, centrifuged to pour out the supernatant, ultrasonically cleaned the copper powder with 50 mL of absolute ethanol for 5 minutes, centrifuged to pour out the supernatant, and the copper powder was dried in a vacuum drying oven (40°C, -0.095MPa, 120min).

(2) Preparation of resin carrier (mixture of resin and solvent): Weigh bisphenol F epoxy resin 170, hydrogenated bisphenol A epoxy resin YDH3000, and diethylene glycol butyl ether according to the mass ratio of 45:25:20:10 Acetate and terpineol were mixed with magnetic stirring to make the mixture uniform to obtain a resin carrier.

(3) Preparation of coarse slurry: Combine the resin carrier, cross-linking agent, accelerator 2-ethyl-4-methylimidazole, and dispersant ED 2020 prepared in step (2) according to the mass ratio of 70:28:1:1 Prepare and mix, stir with a high-speed disperser to obtain the resin component, mix copper powder and carbon black (D50 = 1 μm) according to a mass ratio of 99.5:0.5 to obtain the copper powder component, mix the above resin component and copper powder component Premix according to the mass ratio of 85:15 to obtain a rough slurry, in which the cross-linking agent is prepared as follows:

Under nitrogen protection, add 5.6g (25mmol) isophorone diisocyanate, 7.3g (50mmol) dodecyl mercaptan, and 50mL anhydrous tetrahydrofuran into a 100mL flask, and add 0.003g (0.025mmol) trihydrofuran under stirring. Ethylamine, react at room temperature for 8 hours, slowly add 100mL petroleum ether to the reaction solution, precipitate a white solid, filter, stir and wash the filtered solid with petroleum ether three times, dry in a vacuum oven (40°C, -0.095MPa, 60min) to obtain Cross-linking agent.

(4) Preparation of slurry: Pour the obtained coarse slurry into a three-roller grinder for primary dispersion, add the primary dispersion slurry to a vacuum degassing machine for deaeration and secondary dispersion, and obtain the antioxidant conductive copper slurry. , the viscosity testing instrument of the anti-oxidation conductive copper slurry adopts Brookfield DV2THA rotational viscometer, using a No. 14 rotor, a rotation speed of 10 rpm, a constant temperature (25°C), within 120 seconds, readings are taken every 30 seconds, and three consecutive measurements are taken. Adjusting the upper and lower extreme values, the viscosity of the anti-oxidation conductive copper slurry is 200-300 Pa·s (25°C).

Example 2

An antioxidant conductive copper slurry was prepared according to the same method as Example 1, wherein the cross-linking agent was prepared according to the method described in Example 1 using 2-mercaptobenzothiazole and diphenylmethane diisocyanate. The viscosity of the anti-oxidation conductive copper slurry is measured by the method described in 1, which is 250-350 Pa·s (25°C).

Example 3

An antioxidant conductive copper slurry was prepared according to the same method as Example 1, wherein the cross-linking agent was prepared using 2-mercaptobenzimidazole and 1,6-hexamethylene diisocyanate according to the method described in Example 1, according to The viscosity of the anti-oxidation conductive copper slurry was measured using the method described in Example 1, which was 150-250 Pa·s (25°C).

Comparative example 1

Prepare antioxidant conductive copper slurry according to the same method as Example 1. The difference from Example 2 is that the cross-linking agent used in Comparative Example 1 is Trixene BI7982. The antioxidant conductive copper slurry is measured according to the method described in Example 1. The viscosity of the slurry is 180-230 Pa·s (25°C).

Table 1 Contents of each component in the examples and comparative examples

Note: The sum of the components of each example in the table is not equal to 100% because of rounding.

Experimental example

The anti-oxidation conductive copper paste obtained in the Examples and Comparative Examples was screen-printed on an ultra-white glass substrate with a size of 200mm*150mm through a screen with a mesh size of 100 to 500. The sample was heated under a nitrogen atmosphere. Pre-cure at 140°C for 5 minutes on the table, and cure at 180°C for 20 minutes. After cooling, measure the sheet resistance; place it at room temperature (environment: 25±2°C, humidity 45±5%) for 6 months, and then measure the sheet resistance. Oxidize in a general blast oven at 200°C for 60 minutes, and then measure the sheet resistance. The test results are shown in Table 2, where A and B represent parallel tests; the sheet resistance measurement method: adopt the test method of Guangzhou Four Probe Technology Co., Ltd. RTS-8 type four-probe tester can obtain direct readings.

Table 2 Performance parameters of Examples and Comparative Examples

As can be seen from the above table, the antioxidant conductive copper slurry described in this application has excellent conductivity and stable oxidation resistance. After six months of natural storage at room temperature, the conductivity of the antioxidant conductive copper slurry has improved. There is almost no change, indicating that it is almost not oxidized; after the above-mentioned anti-oxidation conductive copper slurry is oxidized in air at 200°C for 60 minutes, although its conductivity decreases, it still has good conductivity. As for Comparative Example 1, the slurry obtained by using the cross-linking agent in the prior art has a higher initial sheet resistance after curing. After being left at room temperature for 6 months or after being oxidized in the air at 200°C for 60 minutes, the sheet resistance It exceeds the measuring range of the testing instrument, and the copper slurry does not show electrical conductivity, indicating that the slurry described in this application has a good antioxidant effect.

The above are only preferred embodiments of the present application, and are not intended to limit the present application in other forms. Any skilled person familiar with the art may make changes or modifications to equivalent changes using the technical contents disclosed above. Example. However, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present application without departing from the content of the technical solution of the present application still fall within the protection scope of the technical solution of the present application.

Claims

An antioxidant conductive copper slurry includes a compound having a thiocarbamate structural unit.
The antioxidant conductive copper slurry according to claim 1, wherein the compound having a thiocarbamate structural unit is obtained by reacting thiol or thiophenol with a polyisocyanate compound.
The anti-oxidation conductive copper slurry according to claim 2, wherein the thiol or thiol is an aliphatic thiol compound with a carbon number of 1-30 and/or an aromatic compound with a carbon number of 2-30. Thiophenol compounds.
The antioxidant conductive copper slurry according to claim 2 or 3, wherein the polyisocyanate compound is selected from the group consisting of isocyanate, p-phenylene diisocyanate, 1,3-diisocyanatotoluene, 1,6- Hexamethylene diisocyanate, 3,3'-dimethyl-4,4'-biphenyl diisocyanate, diphenylmethane-4,4'-diisocyanate, isophorone diisocyanate, trimethylhexamethylene Diisocyanate, m-xylylene diisocyanate, o-xylylene diisocyanate, 2,6-diisocyanate toluene, 2,4-diisocyanate toluene, 2,5-diisocyanate toluene, 1,4-cyclohexyl diisocyanate Isocyanate, 4,4-diisocyanate dicyclohexylmethane, 1,4-cyclohexanedimethyldiisocyanate, trimethylhexanediisocyanate, tetramethylxylylenediisocyanate, L-lysine diisocyanate , one or more of L-lysine triisocyanate and triphenylmethane triisocyanate.
The anti-oxidation conductive copper slurry according to any one of claims 1 to 4, wherein, in terms of mass percentage in the anti-oxidation conductive copper slurry, the said anti-oxidation conductive copper slurry has a thiocarbamate structure. The unit compound is 1-10%, preferably 2-7%.
The anti-oxidation conductive copper slurry according to any one of claims 1 to 5, wherein the anti-oxidation conductive copper slurry further contains copper powder, resin, accelerator, auxiliary agent and conductive enhancement filler.
The anti-oxidation conductive copper slurry according to claim 6, wherein the particle size D50 of the copper powder is 0.1-10 μm. Preferably, the shape of the copper powder is flake, spherical and/or dendritic.
The antioxidant conductive copper slurry according to claim 6 or 7, wherein the resin is selected from one of epoxy resin, polyamide resin, saturated polyester resin, polyurethane resin, acrylic resin and silicone resin or Two or more types.
A method for preparing anti-oxidation conductive copper slurry, including:

Mix a resin, a solvent, a compound having a thiocarbamate structural unit, an accelerator and an auxiliary agent to obtain a first mixture;

Mix copper powder and conductive reinforcing filler to obtain a second mixture;

The first mixture and the second mixture are mixed to obtain an oxidation-resistant conductive copper slurry.
The method according to claim 9, wherein the first mixture and the second mixture are mixed and then subjected to primary dispersion and secondary dispersion to obtain the anti-oxidation conductive copper slurry.