Oxazoline polymer as well as preparation method and application thereof

Abstract

The invention provides an oxazoline polymer as well as a preparation method and application thereof. Comprising the following steps: (1) adding 10-50 parts by weight of an oxazolinyl monomer as shown in a formula I, 50-90 parts by weight of an alkylene monomer and 0.5-3 parts by weight of an initiator into 150-250 parts by mass of a solvent at 40-80 DEG C, and mixing to obtain a mixture; and (2) copolymerizing the mixture at 40-90 DEG C to obtain the oxazoline group-containing copolymer, when the mass part of the initiator is 1.5-3, the initiator is slowly added; the oxazolinyl monomer shown in the formula I and the alkylene monomer are slowly added. The oxazoline polymer monomer obtained by the preparation method provided by the invention is small in residual quantity, low in viscosity, good in fluidity and good in crosslinking performance.

Description

Technical Field

[0001] The invention relates to an oxazoline polymer and a preparation method and application thereof. Background Art

[0002] Acrylate polymers are widely used in coatings, adhesives, rubber products, plastic anti-buffers and other industries. The initiation system of polymers generally adopts two methods, namely thermal initiation and redox initiation. The thermal initiation reaction temperature is high, the operability requirements are high, and the energy consumption is large. Secondly, the post-treatment process of oil-soluble initiators produces more or less toxic substances, which is not conducive to the green and environmentally friendly production of products. Traditional coating materials are mainly solvent-based. The emission of volatile organic compounds in coating materials is harmful to the human body and the environment. With the enhancement of environmental awareness and the establishment of environmental protection laws and regulations, traditional solvent-based coating materials are increasingly restricted. Therefore, low-pollution and environmentally friendly water-based coating materials are increasingly showing their importance. Only after the coating film of water-based coating materials is cross-linked and cured, can the coating performance equivalent to that of solvent-based coating materials, such as water resistance, acid and alkali resistance and thermal stability, etc. Therefore, the quality of the cross-linking characteristics of its cross-linking agent directly affects the quality of the coating material.

[0003] Active polyacrylate crosslinking agent is a polyacrylate with active functional groups on the main chain of polyacrylate. It is obtained by modifying polyacrylate with reactive oxazoline along the main chain of the polymer. Oxazoline is a five-membered heterocyclic ring containing nitrogen and oxygen elements. Since the oxazoline ring can react chemically with polymers containing carboxylic acid, anhydride, epoxy, phenol, thiol, halogen and other groups to produce crosslinking, the thermal stability and hydrolysis resistance of the polymer are significantly improved. The reaction does not produce toxic byproducts and is more environmentally friendly. However, if there are more monomers remaining, on the one hand, the application effect will be reduced, and on the other hand, the residual monomers will have a strong odor, which will affect environmental safety.

[0004] The development of cross-linking agents containing oxazoline groups and their preparation processes to control monomer residues in polymers and improve the cross-linking properties of cross-linking agents has extremely high industrial value. Summary of the invention

[0005] The technical problem to be solved by the present invention is to overcome the defects of the prior art that the types of oxazoline-based copolymers are few and the cross-linking performance is poor. Therefore, the present invention provides an oxazoline polymer and a preparation method and application thereof. The oxazoline-based copolymer provided by the present invention has good cross-linking performance, less monomer residue and good application prospect.

[0006] The present invention provides a method for preparing an oxazoline-containing copolymer, which comprises the following steps:

[0007] Step (1): adding 10-50 parts by weight of an oxazoline-based monomer of formula I, 50-90 parts by weight of an olefin-based monomer and 0.5-3 parts by weight of an initiator to 150-250 parts by weight of a solvent at 40-80° C. to obtain a mixture;

[0008] Step (2): copolymerizing the mixture at 40-90° C. to obtain the oxazoline-containing copolymer;

[0009] Wherein, the oxazoline monomer shown in formula I is ;

[0010] R1 is a C containing one or more unsaturated carbon-carbon double bonds 2-6 alkenyl;

[0011] R2, R3, R4 and R5 are independently H, halogen, C 1-20 Alkyl, C substituted with one or more hydroxyl groups 1-20 Alkyl, C substituted by one or more amino groups 1-20 Alkyl or C substituted by one or more halogen 1-20 alkyl;

[0012] The olefin monomer is selected from polyethylene glycol methyl acrylate, polyethylene glycol diacrylate and One or more of;

[0013] R6 is H or C 1-20 Alkyl, C substituted with one or more hydroxyl groups 1-20 Alkyl, C substituted by one or more amino groups 1-20 Alkyl or C substituted by one or more halogen 1-20 alkyl;

[0014] R7 is C 1-20 Alkyl, C substituted with one or more hydroxyl groups 1-20 Alkyl, C substituted by one or more amino groups 1-20 Alkyl or C substituted by one or more halogen 1-20 alkyl;

[0015] Wherein, when the mass fraction of the initiator is 1.5-3, the initiator is added slowly;

[0016] The oxazoline monomer represented by formula I and the olefin monomer are added in a slow manner.

[0017] In one embodiment, the C containing one or more unsaturated carbon-carbon double bonds 2-6The alkenyl group contains a C=C double bond terminal group, preferably vinyl, isopropenyl (2-propen-2-yl), 2-propen-1-yl, 3-buten-1-yl or 4-penten-1-yl, and further preferably, R1 is vinyl or isopropenyl, such as isopropenyl.

[0018] In one embodiment, the halogen is fluorine, chlorine, bromine or iodine.

[0019] In one embodiment, the C 1-20 Alkyl is a straight chain or branched C 1-20 Alkyl, preferably C 1-6 Alkyl, for example methyl, ethyl, n-propyl, isopropyl, n-butyl, tert-butyl or isobutyl.

[0020] In one embodiment, in the oxazoline monomer represented by formula I, R2, R3, R4 and R5 are H.

[0021] Preferably, the oxazoline-based monomer shown in formula I is selected from 2-vinyl-2-oxazoline, 2-vinyl-4-methyl-2-oxazoline, 2-vinyl-5-methyl-2-oxazoline, 2-isopropenyl-2-oxazoline, 2-isopropenyl-4-methyl-2-oxazoline, 2-isopropenyl-5-methyl-2-oxazoline, 2-isopropenyl-4-ethyl-2-oxazoline, 2-isopropenyl-5-ethyl-2-oxazoline, 2-isopropenyl-4,4-dimethyl-2-oxazoline, 2-isopropenyl-5,5-dimethyl-2-oxazoline and p-phenylenediyl-2-oxazoline, for example, 2-vinyl-2-oxazoline and / or 2-isopropenyl-2-oxazoline.

[0022] In one embodiment, R6 is H or C 1-6 Alkyl, preferably, R6 is H or methyl.

[0023] Preferably, the olefin-based monomer is methacrylic acid C 1-20 - alkyl esters, such as methacrylate C 1-12 -alkyl esters.

[0024] In one embodiment, the olefin monomer is selected from one or more of methyl (meth)acrylate, ethyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, tert-butyl (meth)acrylate, sec-butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, methyl acrylate, ethyl acrylate, n-butyl acrylate, polyethylene glycol (meth)acrylate (e.g., polyethylene glycol (meth)acrylate having a molecular weight of 200-1000), polyethylene glycol diacrylate (e.g., polyethylene glycol diacrylate having a molecular weight of 200-1000), tert-butyl acrylate, 2-hydroxyethyl (meth)acrylate, 2-ethylhexyl acrylate, 2-ethylhexyl methacrylate, and lauryl acrylate. It is particularly preferred to use one or more of methyl acrylate, methyl methacrylate, n-butyl acrylate, tert-butyl methacrylate, 2-hydroxyethyl (meth)acrylate, and lauryl acrylate, for example, one or more of methyl methacrylate, n-butyl acrylate, 2-hydroxyethyl methacrylate, and lauryl acrylate.

[0025] In one embodiment, the solvent is water and / or an organic solvent, such as an alcohol solvent, an aromatic compound solvent and / or an ether solvent, such as ethanol and / or isopropanol, such as toluene, and such as THF, preferably water.

[0026] In one embodiment, the initiator is selected from one or more of organic peroxides, azo initiators (such as azobisisobutyronitrile), persulfates, bisulfites and inorganic peroxides.

[0027] The organic peroxide may be a diacyl peroxide (e.g. benzoyl peroxide) or a C 1-4 Alkyl peroxy organic peroxides (e.g. tert-butyl peroxyisopropyl carbonate, tert-butyl peroxy 2-ethylhexanoate) or organic peroxides having a ROO- group (wherein R represents an aliphatic hydrocarbon group having 5 or more carbon atoms, preferably 5-10 carbon atoms), etc.

[0028] The persulfate may be potassium perhydrochloride, ammonium persulfate or sodium persulfate.

[0029] The bisulfite may be potassium bisulfite or sodium bisulfite.

[0030] The redox agent may be selected from: a persulfate / hydrogen peroxide + reducing agent system, an organic peroxide / organic hydroperoxide + reducing agent system or a transition metal oxidation + reducing agent system. Among the redox agents, the persulfate is selected from at least one of the following combinations: ammonium persulfate, potassium persulfate and sodium persulfate. The redox agent, the organic peroxide may be selected from at least one of the following combinations: benzoyl peroxide, N,N-dimethylbenzene, N,N-dimethyl-p-toluidine, cumene hydroperoxide or N,N-dimethyl-p-toluidine, etc. The reducing agent may be selected from at least one of the following combinations: sodium thiosulfate, sodium bisulfite, sodium sulfite, ferrous sulfate, sodium pyrosulfite, sodium formaldehyde sulfoxylate, ascorbic acid, ethylenediamine, sodium ethylenediaminetetraacetic acid, glycine, N-isopropylhydroxylamine, etc., particularly preferably sodium bisulfite, ferrous sulfate and N-isopropylhydroxylamine.

[0031] In one embodiment, the oxazoline monomer of formula I is 2-isopropenyl-2-oxazoline, and the olefin monomer is methyl methacrylate and hydroxyethyl methacrylate;

[0032] Alternatively, the oxazoline-based monomer represented by formula I is 2-isopropenyl-2-oxazoline, and the olefin-based monomer is n-butyl acrylate, hydroxyethyl methacrylate and lauryl acrylate;

[0033] Alternatively, the oxazoline-based monomers shown in formula I are 2-vinyl-2-oxazoline and 2-isopropenyl-2-oxazoline, and the olefin-based monomers are methyl methacrylate and hydroxyethyl methacrylate.

[0034] In one embodiment, the solvent is water.

[0035] In one embodiment, the initiator is a persulfate and / or a bisulfite, such as ammonium persulfate, or ammonium persulfate and sodium bisulfite (for example, ammonium persulfate and sodium bisulfite in a molar ratio of 1:0.9). Preferably, the initiator is used in the form of an initiator aqueous solution, wherein the mass ratio of the initiator to water is 1:10.

[0036] In one embodiment, the weight proportion of the oxazoline monomer represented by formula I is 30-40 parts.

[0037] In one embodiment, the weight percentage of the olefin-based monomer is 60-80 parts.

[0038] In one embodiment, in the copolymerization reaction, the mass fraction of 2-vinyl-2-oxazoline is 0-20, such as 0 or 10.

[0039] In one embodiment, in the copolymerization reaction, the mass fraction of the 2-isopropenyl-2-oxazoline is 15-35, such as 20 or 30.

[0040] In one embodiment, in the copolymerization reaction, the mass fraction of methyl methacrylate is 0-35, such as 0 or 30.

[0041] In one embodiment, in the copolymerization reaction, the mass fraction of n-butyl acrylate is 0-35, such as 0 or 30.

[0042] In one embodiment, in the copolymerization reaction, the mass fraction of hydroxyethyl methacrylate is 20-60, such as 30, 40 or 50.

[0043] In one embodiment, in the copolymerization reaction, the mass fraction of lauryl acrylate is 0-15, such as 0 or 10.

[0044] In one embodiment, in the copolymerization reaction, the mass ratio of the water to the 2-isopropenyl-2-oxazoline is 200:(15-35), for example, 10:1 or 20:3.

[0045] In one embodiment, in the copolymerization reaction, the mass ratio of the initiator to the water is (0.5-2.5):200, for example, 1:200 or 1:100.

[0046] In one embodiment, the copolymerization reaction temperature is 40-90°C, such as 80-90°C, preferably 50°C, 75°C or 85°C.

[0047] In one embodiment, the initiator is persulfate, the mixing is performed at 70-80° C. (eg, 75° C.), and the copolymerization is performed at 80-90° C. (eg, 85° C.).

[0048] In one embodiment, the initiator is persulfate and bisulfite, the mixing is performed at 40-60° C. (eg, 50° C.), and the copolymerization is performed at 40-60° C. (eg, 50° C.).

[0049] In one embodiment, the mixing temperature is 40-80°C, such as 70-80°C, preferably 75°C.

[0050] In one embodiment, the slowly adding is dropwise adding.

[0051] In one embodiment, the initiator is used in a solution state, and the feeding rate is 0.5 to 3 parts by mass per hour (e.g., 0.5 g / h to 3 g / h), such as 1 or 2 parts by mass per hour (e.g., 1 g / h or 2 g / h), based on the mass of the initiator. Wherein parts by mass and g / h are the feeding mass per hour based on the mass of the initiator (the feeding rate is 20.5-23 g / h based on the total weight of the solution, such as 21 g / h, 22 g / h)

[0052] In one embodiment, the feeding rate of the oxazoline-based monomer represented by Formula I is 15 to 45 parts by mass per hour (e.g., 15-45 g / h), for example, 20 parts by mass, 30 parts by mass or 40 parts by mass per hour (e.g., 20 g / h, 30 g / h or 40 g / h).

[0053] In one embodiment, the olefin-based monomer feeding rate is 50 to 90 parts by mass per hour (eg, 50-90 g / h), such as 70, 60 or 80 parts by mass per hour (eg, 70 g / h, 60 g / h or 80 g / h).

[0054] In one embodiment, the mixing and copolymerization are carried out in a protective gas, such as nitrogen.

[0055] In one embodiment, the weight parts of the oxazoline monomer and the olefin monomer shown in formula I are respectively the weight percentages of the monomers in the total weight of all monomers (i.e. the total weight of the oxazoline monomer and the olefin monomer shown in formula I).

[0056] In one embodiment, the preparation method comprises the following steps:

[0057] Step (1): adding 10-50 parts by weight of an oxazoline monomer of formula I, 50-90 parts by weight of an olefin monomer and 0.5-3 parts by weight of an initiator to 150-250 parts by weight of a solvent in a protective gas atmosphere at 40-80° C. to obtain a mixture;

[0058] Wherein, when the mass fraction of the initiator is 1.5-3, the initiator is used in a solution state (the solvent is the above solvent), and the initiator is slowly added; the oxazoline-based monomer shown in formula I and the olefin-based monomer are slowly added to the solvent;

[0059] Step (2): subjecting the mixture to a polymerization (copolymerization) reaction at 40-90° C. to obtain the oxazoline-containing copolymer.

[0060] In one embodiment, the preparation method comprises the following post-processing step: filtering after the reaction is completed.

[0061] The progress of the copolymerization reaction is monitored by conventional methods in the art, such as HPLC, and the reaction endpoint is generally when the monomer is completely consumed or no longer reacts. The copolymerization reaction time can be 4-8 hours, such as 6 hours.

[0062] In one embodiment, the initiator has a weight percentage of 0.5-1.5, and the initiator can be added all at once, in batches, or slowly (eg, dropwise).

[0063] The present invention provides an oxazoline-containing copolymer, which is obtained by copolymerizing 10-50 parts by weight of an oxazoline-based monomer shown in formula I and 50-90 parts by weight of an olefin-based monomer;

[0064] The oxazoline monomer shown in formula I is ;

[0065] The olefin monomer is ;

[0066] Wherein, R1, R2, R3, R4, R5, R6 and R7 are as described in any embodiment of the present invention.

[0067] In one embodiment, the copolymerization reaction further comprises the initiator described in any embodiment of the present invention and / or the solvent described in any embodiment of the present invention.

[0068] In one embodiment, the oxazoline-based monomer and the olefin-based monomer represented by formula I are as described in any embodiment of the present invention.

[0069] In one embodiment, the oxazoline-containing copolymer is prepared by the above-mentioned preparation method.

[0070] In one embodiment, the oxazoline group-containing copolymer is liquid.

[0071] In one embodiment, the viscosity of the copolymer containing oxazoline groups is ≥30 mPa·s (25°C) and ≤200 mPa·s, for example, 50-70 mPa·s, preferably 57 mPa·s, 69 mPa·s, 91 mPa·s, 51 mPa·s, 70 mPa·s or 62 mPa·s.

[0072] In one embodiment, the molecular weight of the copolymer containing oxazoline groups is 14000-20000 Mn, for example, 15542 Mn, 14258 Mn, 19254 Mn, 16875 Mn, 16303 Mn or 15962 Mn.

[0073] The present invention provides a use of the above-mentioned oxazoline-containing copolymer, which is to use the above-mentioned oxazoline-containing copolymer as a crosslinking agent (such as a polyacrylic acid resin crosslinking agent), a dispersant or a lithium battery adhesive.

[0074] Without violating the common sense in the art, the above-mentioned preferred conditions can be arbitrarily combined to obtain the preferred embodiments of the present invention.

[0075] The reagents and raw materials used in the present invention are commercially available.

[0076] The positive and progressive effects of the present invention are: the polymer provided by the present invention has a small amount of residual monomers, good cross-linking performance, low viscosity, good fluidity, and good application prospects; the preparation process has a small amount of residual monomers, convenient operation, and a high yield. DETAILED DESCRIPTION

[0077] The present invention is further described below by way of examples, but the present invention is not limited to the scope of the examples. The experimental methods in the following examples without specifying specific conditions are carried out according to conventional methods and conditions, or selected according to the product specifications.

[0078] The following abbreviations are used in the following examples and comparative examples:

[0079] VOXA: 2-vinyl-2-oxazoline;

[0080] IPOX: 2-isopropenyl-2-oxazoline;

[0081] MMA: methyl methacrylate;

[0082] BA: n-butyl acrylate.

[0083] HEMA: Hydroxyethyl methacrylate.

[0084] LA: Lauryl acrylate.

[0085] Example 1

[0086] (1) Nitrogen is introduced into the reactor to remove the air. After the air in the reactor is completely removed, 200 parts by weight of deionized water and 2 parts by weight of initiator ammonium persulfate are added into the reactor and stirred to dissolve.

[0087] (2) The system temperature was maintained at 75°C, and 30 parts by mass of monomer A: 2-isopropenyl-2-oxazoline (IPOX), 30 parts by mass of methyl methacrylate (MMA) and 40 parts by mass of hydroxyethyl methacrylate (HEMA) were added dropwise into the reactor for 1 hour.

[0088] (3) After the monomer addition is completed, the temperature is raised to 85°C and the reaction is continued at a constant temperature for 6 hours. After the reaction is terminated, the mixture is taken out and filtered to obtain copolymer A.

[0089] Example 2

[0090] (1) Nitrogen was introduced into the reactor to remove air. After the air in the reactor was completely removed, 180 parts by weight of deionized water was added and the system temperature was maintained at 75°C.

[0091] (2) Stir and dissolve 20 parts by weight of deionized water and 2 parts by weight of initiator ammonium persulfate, and add them dropwise into the reactor for 1 hour.

[0092] (3) Simultaneously, 30 parts by weight of monomer A: 2-isopropenyl-2-oxazoline (IPOX), 30 parts by weight of n-butyl acrylate (BA), 30 parts by weight of hydroxyethyl methacrylate (HEMA), and 10 parts by weight of lauryl acrylate (LA) were added dropwise into the reactor for 1 hour.

[0093] (4) After the monomer addition is completed, the temperature is raised to 85°C and the reaction is continued at a constant temperature for 6 hours. After the reaction is terminated, the mixture is taken out and filtered to obtain copolymer B.

[0094] According to the operation of the above-mentioned Example 2, the condition parameters for preparing crosslinking agents A, B, C, D, E, F, G, H, I, J, K and L in each example and comparative example are summarized in the following Tables 1 and 2 (wherein Tables 1 and 2 respectively describe the feeding amount (in g), feeding operation and temperature operation of Examples 1-6 and Comparative Examples 1-6).

[0095] Table 1 Preparation of oxazoline-containing polymers

[0096]

[0097]

[0098] Table 2 Preparation of oxazoline-containing polymers

[0099]

[0100] In Tables 1 and 2 above, in Example 6 and Comparative Example 6, the molar ratio of ammonium persulfate to sodium bisulfite is 1:0.9, and the initiator is added dropwise, and the operation is to dissolve ammonium persulfate in 10 times the mass of water to obtain initiator solution 1, and dissolve sodium bisulfite in 10 times the mass of water to obtain initiator solution 2, and then dropwise add them into the reactor at a uniform speed over 1 hour. In the above table, dropwise addition refers to slowly adding the monomer or initiator to the reactor within 1 hour. In the above table, 75-85 means mixing at 75°C and reacting at a constant temperature at 85°C.

[0101] Effect test example 1

[0102] The crosslinking agents A, B, C, D, E, F, G, H, I, J, K and L obtained in the above examples and comparative examples were tested, as shown in Tables 3 and 4 below.

[0103] Monomer residual test: reference .

[0104] Viscosity test: Referring to GB / T 2794-2013, 30 g of the filtrate of the oxazoline-based polymer in each example and comparative example was taken and measured at 25° C. using a Brookfield DVS+ rotational viscometer.

[0105] Molecular weight test: Referring to GB / T 31816-2015, the oxazoline-containing polymers in the examples and comparative examples were tested for molecular weight using a WATERS 2414 device.

[0106] Cross-linking performance test: Take 1g of oxazoline-based polymer, add 10g of polyacrylic acid resin (Mn=5.5w, solid content 50%), mix well, dry to form a film, weigh 1g of the dried film, wrap it with filter paper, put it in water and reflux at 100℃ for 24h, take out the sample, dry it and weigh it.

[0107] Cross-linking performance = weight of sample after reflux and drying / weight of dried film sample before reflux*100%.

[0108] Table 3 Test results of oxazoline-containing polymers.

[0109]

[0110] Table 4 Test results of oxazoline-containing polymers

[0111]

[0112] As can be seen from Tables 3 and 4 above, in Examples 1-6, the final monomer residue is less than 0.1%, and the polymer has low viscosity, good fluidity, small molecular weight, and overall cross-linking performance of >90%.

Claims

1. A method for preparing an oxazoline-containing copolymer, characterized in that: It includes the following steps: Step (1): adding 10-50 parts by weight of an oxazoline-based monomer of formula I, 50-90 parts by weight of an olefin-based monomer and 0.5-3 parts by weight of an initiator to 150-250 parts by weight of a solvent at 40-80° C. to obtain a mixture; Step (2): copolymerizing the mixture at 40-90° C. to obtain the oxazoline-containing copolymer; Wherein, the oxazoline monomer shown in formula I is ; R1 is a C containing one or more unsaturated carbon-carbon double bonds 2-6 alkenyl; R2, R3, R4 and R5 are independently H, halogen, C 1-20 Alkyl, C substituted with one or more hydroxyl groups 1-20 Alkyl, C substituted by one or more amino groups 1-20 Alkyl or C substituted by one or more halogen 1-20 alkyl; The olefin monomer is selected from polyethylene glycol methyl acrylate, polyethylene glycol diacrylate and One or more of; R6 is H or C 1-20 Alkyl, C substituted with one or more hydroxyl groups 1-20 Alkyl, C substituted by one or more amino groups 1-20 Alkyl or C substituted by one or more halogen 1-20 alkyl; R7 is C 1-20 Alkyl, C substituted with one or more hydroxyl groups 1-20 Alkyl, C substituted by one or more amino groups 1-20 Alkyl or C substituted by one or more halogen 1-20 alkyl; Wherein, when the mass fraction of the initiator is 1.5-3, the initiator is added slowly; The oxazoline monomer represented by formula I and the olefin monomer are added in a slow manner.

2. The method for preparing an oxazoline-based copolymer according to claim 1, wherein: It meets one or more of the following conditions: (1) The C containing one or more unsaturated carbon-carbon double bonds 2-6 The alkenyl group contains a C=C double bond terminal group, preferably vinyl, isopropenyl (2-propen-2-yl), 2-propen-1-yl, 3-buten-1-yl or 4-penten-1-yl, and further preferably, R1 is vinyl or isopropenyl, such as isopropenyl; (2) The halogen is fluorine, chlorine, bromine or iodine; (3) C 1-20 Alkyl is a straight chain or branched C 1-20 Alkyl, preferably C 1-6 Alkyl, for example methyl, ethyl, n-propyl, isopropyl, n-butyl, tert-butyl or isobutyl; (4) The solvent is water and / or an organic solvent, such as an alcohol solvent, an aromatic compound solvent and / or an ether solvent, such as ethanol and / or isopropanol, such as toluene, and such as THF, preferably water; (5) The initiator is selected from one or more of organic peroxides, azo initiators, persulfates, bisulfites and inorganic peroxides.

3. The method for preparing an oxazoline-based copolymer according to claim 2, wherein: It meets one or more of the following conditions: (1) In the oxazoline monomer of formula I, R2, R3, R4 and R5 are H; Preferably, the oxazoline-based monomer represented by formula I is selected from 2-vinyl-2-oxazoline, 2-vinyl-4-methyl-2-oxazoline, 2-vinyl-5-methyl-2-oxazoline, 2-isopropenyl-2-oxazoline, 2-isopropenyl-4-methyl-2-oxazoline, 2-isopropenyl-5-methyl-2-oxazoline, 2-isopropenyl-4-ethyl-2-oxazoline, 2-isopropenyl-5-ethyl-2-oxazoline, 2-isopropenyl-4,4-dimethyl-2-oxazoline, 2-isopropenyl-5,5-dimethyl-2-oxazoline and p-phenylenediyl-2-oxazoline, for example, 2-vinyl-2-oxazoline and / or 2-isopropenyl-2-oxazoline; (2) R6 is H or C 1-6 Alkyl; for example, the olefin monomer is methacrylic acid C 1-20 -alkyl esters; further such as methacrylic acid C 1-12 - alkyl esters; Preferably, the olefin-based monomer is selected from one or more of methyl (meth)acrylate, ethyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, tert-butyl (meth)acrylate, sec-butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, methyl acrylate, ethyl acrylate, n-butyl acrylate, polyethylene glycol (meth)acrylate, polyethylene glycol diacrylate, tert-butyl acrylate, 2-hydroxyethyl (meth)acrylate, 2-ethylhexyl acrylate, 2-ethylhexyl methacrylate and lauryl acrylate; particularly preferably selected from one or more of methyl acrylate, methyl methacrylate, n-butyl acrylate, tert-butyl methacrylate, 2-hydroxyethyl (meth)acrylate, lauryl acrylate, for example, selected from one or more of methyl methacrylate, n-butyl acrylate, 2-hydroxyethyl methacrylate and lauryl acrylate; (3) The persulfate is potassium perhydrochloride, ammonium persulfate or sodium persulfate; (4) The bisulfite is potassium bisulfite or sodium bisulfite.

4. The method for preparing an oxazoline-based copolymer according to claim 2, wherein: It meets one or more of the following conditions: (1) The oxazoline monomer represented by formula (I) is 2-isopropenyl-2-oxazoline, and the olefin monomer is methyl methacrylate and hydroxyethyl methacrylate; Alternatively, the oxazoline-based monomer represented by formula I is 2-isopropenyl-2-oxazoline, and the olefin-based monomer is n-butyl acrylate, hydroxyethyl methacrylate and lauryl acrylate; Alternatively, the oxazoline monomers represented by formula I are 2-vinyl-2-oxazoline and 2-isopropenyl-2-oxazoline, and the olefin monomers are methyl methacrylate and hydroxyethyl methacrylate; (2) The solvent is water; (3) The initiator is a persulfate and / or a bisulfite, such as ammonium persulfate or "ammonium persulfate and sodium bisulfite", wherein the molar ratio of ammonium persulfate to sodium bisulfite is preferably 1:0.

9. Preferably, the initiator is used in the form of an initiator aqueous solution, wherein the mass ratio of initiator to water is, for example, 1:10; (4) The weight proportion of the oxazoline monomer represented by formula I is 30-40 parts; (5) The weight proportion of the olefin-based monomer is 60-80 parts.

5. The method for preparing the oxazoline-containing copolymer according to claim 3 or 4, characterized in that: It meets one or more of the following conditions: (1) The mass fraction of 2-vinyl-2-oxazoline is 0-20, for example 0 or 10; (2) the mass fraction of the 2-isopropenyl-2-oxazoline is 15-35, for example 20 or 30; (3) The mass fraction of methyl methacrylate is 0-35, for example, 0 or 30; (4) The mass fraction of n-butyl acrylate is 0-35, for example, 0 or 30; (5) The mass fraction of the hydroxyethyl methacrylate is 20-60, for example, 30, 40 or 50; (6) The mass fraction of lauryl acrylate is 0-15, for example, 0 or 10; (7) The mass ratio of the water to the 2-isopropenyl-2-oxazoline is 200:(15-35), for example, 10:1 or 20:3; (8) The mass ratio of the initiator to the water is (0.5-2.5):200, for example 1:200 or 1:100; (9) The copolymerization reaction temperature is 40-90°C, for example 80-90°C, preferably 50°C, 75°C or 85°C; Further preferably, the initiator is a persulfate, the mixing is carried out at 70-80°C, and the copolymerization is carried out at 80-90°C, for example, the mixing temperature is 75°C, and the copolymerization is carried out at 85°C; Alternatively, the initiator is a persulfate and a bisulfite, the mixing is performed at 40-60°C, and the copolymerization is performed at 40-60°C, for example, the mixing temperature is 50°C, and the copolymerization is performed at 50°C; (10) The slow addition is dropwise addition.

6. The method for preparing the oxazoline-containing copolymer according to claim 1, wherein: It meets one or more of the following conditions: (1) The initiator is used in a solution state, and the feeding rate is 0.5 to 3 parts by mass per hour, such as 1 or 2 parts by mass per hour, preferably 1 g / h or 2 g / h, based on the mass of the initiator; (2) The feeding rate of the oxazoline monomer represented by formula I is 15 to 45 parts by mass per hour, for example, 20 parts by mass, 30 parts by mass or 40 parts by mass per hour, preferably 20 g / h, 30 g / h or 40 g / h; (3) the olefin-based monomer feeding rate is 50 to 90 parts by mass per hour, for example, 70 parts by mass, 60 parts by mass or 80 parts by mass per hour, preferably 70 g / h, 60 g / h or 80 g / h; (4) The mixing and copolymerization are carried out in a protective gas, such as nitrogen; (5) The weight percentages of the oxazoline monomer and the olefin monomer represented by formula (I) are the weight percentages of the monomers in the total weight of all monomers.

7. The method for preparing the oxazoline-containing copolymer according to claim 1, wherein: The preparation method comprises the following steps: Step (1): adding 10-50 parts by weight of the oxazoline monomer of formula I, 50-90 parts by weight of the olefin monomer and 0.5-3 parts by weight of the initiator to 150-250 parts by weight of the solvent in a protective gas atmosphere at 40-80° C. to obtain a mixture; Wherein, when the mass fraction of the initiator is 1.5-3, the initiator is used in a solution state, and the initiator is slowly added; the oxazoline-based monomer shown in formula I and the olefin-based monomer are slowly added to the solvent; Step (2): polymerizing the mixture at 40-90° C. to obtain the oxazoline-containing copolymer; Preferably, the preparation method comprises the following post-processing step: filtering after the reaction is completed.

8. An oxazoline-containing copolymer, characterized in that: It is obtained by copolymerizing 10-50 parts by weight of oxazoline monomer and 50-90 parts by weight of olefin monomer; Wherein, the olefin-based monomer is as described in any one of claims 1-7; the oxazoline-based monomer is the oxazoline-based monomer represented by formula I as described in any one of claims 1-7.

9. The oxazoline-containing copolymer according to claim 8, wherein: It meets one or more of the following conditions: (1) The oxazoline-containing copolymer is prepared by the preparation method according to any one of claims 1 to 7; (2) The oxazoline-containing copolymer is a liquid; (3) The viscosity of the copolymer containing oxazoline groups at 25° C. is ≥30 mPa·s and ≤200 mPa·s, for example, 50-70 mPa·s, preferably 57 mPa·s, 69 mPa·s, 91 mPa·s, 51 mPa·s, 70 mPa·s or 62 mPa·s; (4) The molecular weight of the copolymer containing oxazoline groups is 14000-20000 Mn, for example, 15542 Mn, 14258 Mn, 19254 Mn, 16875 Mn, 16303 Mn or 15962 Mn.

10. Use of the oxazoline-containing copolymer as claimed in claim 8 or 9, characterized in that: The use is that the oxazoline group-containing copolymer is used as a crosslinking agent, a dispersant or a lithium battery binder, and the crosslinking agent is, for example, a polyacrylic acid resin crosslinking agent.

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