KR-20260067433-A - COPOLYMER FOR SEPARATOR AND SECONDARY BATTERY USING THEREOF

KR20260067433AKR 20260067433 AKR20260067433 AKR 20260067433AKR-20260067433-A

Abstract

The present invention relates to a copolymer comprising a monomer unit containing a sulfur atom, an acrylonitrile-based monomer unit, an acrylate-based monomer unit comprising a linear alkyl group having 1 to 20 carbon atoms, and a vinyl acetate-based monomer unit, a slurry composition containing the same, a separator, and a secondary battery.

Inventors

김영수
김승헌
박가영
오세욱
권세만

Assignees

주식회사 한솔케미칼

Dates

Publication Date: 20260513
Application Date: 20241104

Claims (13)

It comprises a monomer unit containing a sulfur atom, an acrylic acid-based monomer unit, an acrylate-based monomer unit containing a linear alkyl group having 1 to 20 carbon atoms, and an acrylate-based monomer unit containing a branched alkyl group having 3 to 10 carbon atoms, and The sulfur atom of the above sulfur atom-containing monomer unit is located at the terminal of a linear alkyl group having 1 to 10 carbon atoms, Copolymer.
In paragraph 1, A combination of acrylonitrile-based monomer units and vinyl acetate-based monomer units or a combination thereof, further comprising Copolymer.
In paragraph 1, Based on 100% by weight of the total weight of the copolymer, the above-mentioned monomer units containing sulfur atoms in an amount of 1% or more and 20% or less by weight; 5 weight% or more and 30 weight% or less of the above acrylic acid-based monomer units; An acrylate-based monomer unit comprising a linear alkyl group having 1 to 20 carbon atoms in an amount of 5 weight% or more and 30 weight% or less; and 1. Acrylate-based monomer units comprising 20% by weight or more and 50% by weight or less of the branched alkyl group having 3 to 10 carbon atoms; Copolymer.
In paragraph 2, Based on 100% by weight of the total weight of the copolymer, the acrylonitrile-based monomer unit in an amount of 20% by weight or more and 40% by weight or less; the vinyl acetate-based monomer unit in an amount of 1% by weight or more and 20% by weight or less; or further comprising a combination thereof, Copolymer.
In paragraph 1, The monomer unit containing the sulfur atom above comprises a monomer unit containing a sulfide group, a monomer unit containing a sulfonate group, a monomer unit containing a sulfone group, a monomer unit containing a sulfonyl ester group, a monomer unit containing a sulfonamide group, a monomer unit containing a sulfonimide group, a monomer unit containing a sulfonyl azide group, a monomer unit containing a sulfonyl hydrazide group, a monomer unit containing a sulfonyl aziridine group, a monomer unit containing a sulfonyl azitidine group, a monomer unit containing a sulfonyl carbamate group, a monomer unit containing a sulfonylurea group, a monomer unit containing a sulfonyl halide group, or a combination thereof. Copolymer.
In paragraph 1, The above acrylic acid-based monomer unit is formed by polymerizing one or more selected from the group consisting of acrylic acid and methacrylic acid, and The above acrylate-series monomer unit comprising a linear alkyl group having 1 to 20 carbon atoms is formed by polymerizing one or more selected from the group consisting of methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, propyl acrylate, propyl methacrylate, butyl acrylate, butyl methacrylate, lauryl acrylate, lauryl methacrylate, stearyl acrylate, and stearyl methacrylate. The above acrylate-series monomer unit containing a branched alkyl group having 3 to 10 carbon atoms is formed by polymerizing one or more selected from the group consisting of isopropyl acrylate, isopropyl methacrylate, sec-butyl acrylate, sec-butyl methacrylate, tert-butyl acrylate, tert-butyl methacrylate, 2-ethylhexyl acrylate, and 2-ethylhexyl methacrylate. Copolymer.
In paragraph 1, The above sulfur atom-containing monomer unit is formed by polymerizing one or more selected from the group consisting of 3-sulfopropyl acrylate and allyl methyl sulfide, Copolymer.
In paragraph 2, The above acrylonitrile-based monomer is formed by polymerizing one or more selected from the group consisting of acrylonitrile and methacrylonitrile, and The above vinyl acetate series monomer unit is formed by the polymerization of vinyl acetate, Copolymer.
In paragraph 1, A monomer repeating unit represented by the following chemical formula 1, comprising Copolymer. [Chemical Formula 1] In the above chemical formula 1, R1 , R2 , and R3 are each independently hydrogen, a linear or branched hydrocarbon having 1 to 4 carbon atoms, or a combination thereof, and R4 is a linear alkyl group having 1 to 20 carbon atoms, and R5 is a branched alkyl group having 3 to 10 carbon atoms, and R6 is hydrogen or an alkali metal, and R7 is a linear alkyl group having 1 to 10 carbon atoms with a sulfur atom located at the terminal, and the sulfur atom is part of a sulfide group, a sulfonate group, a sulfone group, a sulfonyl ester group, a sulfonamide group, a sulfonimide group, a sulfonylazide group, a sulfonyl hydrazide group, a sulfonylaziridine group, a sulfonylazitidine group, a sulfonyla carbamate group, a sulfonylurea group, or a sulfonyl halide group, and 0.05≤a≤0.3, 0.2≤b≤0.5, 0.05≤c≤0.3, 0≤d≤0.2, 0.01≤e≤0.2 and 0≤f≤0.4, and a+b+c+d+e+f=1.
A separation membrane having a coating layer containing inorganic material formed thereon, wherein the contact angle between the surface of the membrane and an aqueous copolymer solution with a solid content of 25 weight% is 90˚ or less, Copolymer.
A copolymer of any one of claims 1 to 10; and Inorganic particles; including, Slurry composition.
A porous substrate comprising a coating layer formed by applying the slurry composition of claim 11, Separator.
including the separator of Clause 12, Secondary battery.

Description

Copolymer for separator and secondary battery using the same The present invention relates to a copolymer and a slurry composition containing the same, a separator, and a secondary battery. Due to their high energy density, lithium-ion batteries are widely used in the electrical, electronic, telecommunications, and computer industries. Following small lithium-ion batteries for portable electronic devices, their applications are expanding to include high-capacity batteries for hybrid and electric vehicles. Although lithium-ion batteries are insulated by a separator, ensuring the thermal and chemical safety of the separator is crucial, as internal or external battery malfunctions or impacts can cause a short circuit between the positive and negative electrodes, potentially leading to overheating and explosion. Currently, polyolefin-based films are widely used as separators, but polyolefins have the disadvantage of severe thermal shrinkage at high temperatures and poor mechanical properties. To improve the stability of such polyolefin-based separation membranes, a porous separation membrane has been developed in which a mixture of inorganic particles and a binder is coated onto a polyolefin porous substrate film. In other words, to suppress thermal shrinkage caused by high temperatures of polyolefin-based separators and battery instability caused by dendrites, inorganic particles are coated together with a binder on one or both sides of a porous separator substrate, thereby providing the inorganic particles with the function of suppressing the shrinkage rate of the substrate, and at the same time, a safer separator can be manufactured through the coating layer. To ensure excellent battery characteristics, the coating layer must be uniformly coated while simultaneously requiring strong adhesion to the substrate. In particular, improvements in the performance and stability of secondary batteries are required through this. The operation and effects of the invention will be described in more detail below through specific embodiments. However, these embodiments are merely examples of the invention and do not define the scope of the invention. Prior to this, terms and words used in this specification and claims should not be interpreted as being limited to their ordinary or dictionary meanings, but should be interpreted in a meaning and concept consistent with the technical spirit of the invention, based on the principle that the inventor can appropriately define the concept of the terms to best describe his invention. Therefore, it should be understood that the configuration of the embodiments described in this specification is merely one of the most preferred embodiments of the present invention and does not represent all of the technical ideas of the present invention, and that various equivalents and modifications that can replace them may exist at the time of filing this application. In this specification, singular expressions include plural expressions unless the context clearly indicates otherwise. In this specification, terms such as “comprising,” “comprising,” or “having” are intended to specify the existence of the implemented features, numbers, steps, components, or combinations thereof, and should be understood as not precluding the existence or addition of one or more other features, numbers, steps, components, or combinations thereof. In the present specification, "a to b" and "a~b" indicating numerical ranges, "to" and "~" are defined as ≥ a and ≤ b. A copolymer of one aspect of the present invention may comprise a monomer unit containing a sulfur atom, an acrylic acid-based monomer unit, an acrylate-based monomer unit containing a linear alkyl group having 1 to 20 carbon atoms, and an acrylate-based monomer unit containing a branched alkyl group having 3 to 10 carbon atoms. In addition, the sulfur atom of the above-mentioned sulfur atom-containing monomer unit may be located at the end of a linear alkyl group having 1 to 10 carbon atoms. The above-mentioned monomer unit containing a sulfur atom can exhibit reactive emulsifier behavior. Typically, reactive emulsifiers can perform functions and roles such as controlling the chemical structure of the polymer, controlling particle size, stabilization, and dispersion during emulsion polymerization. The above-mentioned sulfur atom-containing monomer unit, which exhibits reactive emulsifier behavior, can surround the edges of the copolymer (water-soluble resin) of the present invention and can control the stable generation and dispersion of particles with large particle sizes compared to conventional water-soluble resins. Therefore, the above-mentioned sulfur atom-containing monomer unit can help increase adhesion to the electrode and achieve low resistance within the secondary battery compared to particles with small particle sizes. In addition, the monomer unit containing the sulfur atom can have a large dipole moment. Therefore, the adhesion to the inorg