Water-dispersible copolymer, preparation method therefor and use thereof

Abstract

The present invention relates to the field of polymer compounds, relating to a water-dispersible copolymer, a preparation method therefor, and a use thereof. The water-dispersible copolymer provided by the present invention comprises repeat units generated from a monomer I, repeat units generated from a monomer II, and repeat units generated from a monomer III. Monomer I is a carbosiloxane dendrimer monomer, monomer II is a cationic monomer having a tertiary amine group, and monomer III is a hydrophilic monomer. The copolymer, or a composition containing said polymer, can be used for surface treatment of paper, and imparts strong water and oil repellent properties to the paper surface.

Description

Water-dispersible copolymer, and preparation method and application thereof TECHNICAL FIELD

[0001] The present application relates to the field of high molecular compounds, and more particularly, to a water-dispersible copolymer, and a preparation method and application thereof. BACKGROUND

[0002] Among the numerous surface treatment agents, the most widely used is the fluorine-containing polymer surface treatment agent. Such surface treatment agent has good water and oil repellency, good heat resistance, good film forming property, high chemical stability and other excellent properties, and is widely used in paper, fabric, packaging materials, water-based paint and other fields. Fluorine-containing polymers are used as paper treatment agents to impart oil repellency due to their extremely low surface energy. However, due to the long carbon chain of fluorine-containing polymers, they are not easily degradable in the natural environment, have high bioaccumulation, and are toxic, which can cause harm to the human body and the environment. Patent CN102575435B published by Daikin Company contains a fluorine-containing copolymer oil repellent for providing excellent water and oil repellency to paper, which is obtained by copolymerizing fluorine-containing (meth) acrylate monomers having 1-6 carbon atoms, hydrophilic monomers and monomers having an anion-providing group. Chinese patent CN111040072A discloses an ethylene-based fluorine-containing copolymer applied to paper-based products, which is obtained by free radical copolymerization of short-chain fluorine-containing monomers with quaternary amine acrylate monomers and acrylic monomers. The water and oil repellent composition is applied to paper-based products. Although existing research shows that short-chain fluorine-containing polymers have good biodegradability and do not have significant bioaccumulation, they do not pose potential harm to human health and the environment, but their water and oil repellency is poor, which is not conducive to further popularization and use.

[0003] In view of the above, some new non-fluorine polymers are proposed to replace existing fluorine-containing surface treatment agents. Among them, silicone polymers are widely used due to their environmental friendliness, excellent performance, low cost and other advantages. Patent documents with publication numbers CN112805434A and CN114573768B disclose a silicone polymer which can be directly dispersed with water to treat fiber products and has excellent water repellency, but the oil repellency is not very good. SUMMARY

[0004] The primary object of the present application is to overcome the problem that the existing non-fluorine treatment agents cannot simultaneously have excellent water and oil repellency, and to provide a water-dispersible copolymer.

[0005] Another object of the present application is to provide a preparation method of a composition containing the above-mentioned water-dispersible copolymer.

[0006] Another object of the present application is to provide a composition prepared by the above-mentioned preparation method.

[0007] Another object of the present application is to provide a paper treatment agent containing the above water-dispersible copolymer, composition.

[0008] Another object of the present application is to provide a paper and / or paper product prepared from the above water-dispersible copolymer, composition or paper treatment agent.

[0009] The above object of the present application is achieved by the following technical solutions.

[0010] A water-dispersible copolymer comprising a repeating unit derived from monomer I, a repeating unit derived from monomer II and a repeating unit derived from monomer III:

[0011] The general structure of monomer I is as follows:

[0012] wherein X is a group having a carbon-carbon double bond;

[0013] R 1 and R 2 are each independently a C1-C 10 alkyl group, a C1-C 10 aryl group or a C1-C 10 aralkyl group, and a is any one of 0, 1 or 2;

[0014] L is an H atom, a C1-C 10 alkyl group, a C1-C 10 aryl group, a C1-C 10 aralkyl group or a silyl group, or the following structure:

[0015] wherein Y is an alkylene group and p is an integer of 1 to 10;

[0016] R 3 and R 4 are each independently a C1-C 10 alkyl group, a C1-C 10 aryl group or a C1-C 10 aralkyl group, and b is any one of 0, 1 or 2;

[0017] M is an H atom, a C1-C 10 alkyl group, a C1-C 10 aryl group, a C1-C 10 aralkyl group or a silyl group;

[0018] The general structure of monomer II is as follows:

[0019] wherein R 5 is an H atom or a C1-C 10 alkyl group;

[0020] Z is N or O;

[0021] Q is a tertiary amine-containing organic group;

[0022] The monomer III is selected from one or more of an acrylate monomer, an acrylamide monomer, an anion-supplying group-containing and polymerizable unsaturated monomer, a polymerizable unsaturated siloxane coupling agent, and a multifunctional and polymerizable unsaturated monomer, the anion-supplying group being a carboxyl group or a sulfonic acid group, the multifunctional group including one or more of a hydroxyl group, an isocyanurate group, an ester group, and an ether group.

[0023] The copolymer and the composition thereof obtained by the present application improve the water and oil repellency by introducing the monomer I having a dendrimer structure and simultaneously cationizing by a quaternization reaction. The molecular structure of the monomer I of the present application in which the silicon atoms in the carbosiloxane unit are radially arranged extends the carbosiloxane unit in the form of a dendrimer, and imparts stronger water and oil repellency to the copolymer, which is advantageous for further improving the water and oil resistance of the paper surface. When water, oil, or the like liquid contacts the surface of the copolymer, the water, oil, or the like liquid is prevented from wetting the surface due to the extremely low surface energy of the copolymer, and a protective film is formed on the paper surface, thereby achieving the water and oil repellency. Therefore, the copolymer has more excellent water and oil repellency than other linear and simply branched polysiloxanes.

[0024] Preferably, the mass ratio of the repeating unit produced by the monomer I, the repeating unit produced by the monomer II, and the repeating unit produced by the monomer III is 20 to 85 wt% : 10 to 40 wt% : 0 to 40 wt%.

[0025] Preferably, in the monomer I, R 1 and R 2 are each independently a methyl group; and / or;

[0026] In L, M is selected from a methyl group or an ethyl group; and / or;

[0027] In the monomer II, R 5 is selected from H or a methyl group; and / or

[0028] X is selected from at least one of an organic group containing an acryloyl group or a methacryloyl group, an organic group containing an alkenyl group and an aryl group, and an alkenyl group having 2 to 10 carbon atoms.

[0029] More preferably, X is at least one of a vinyl group, an allyl group, an acryloyloxy group, a methacryloyloxy group, an acrylamide group, or a methacrylamide group.

[0030] Preferably, the monomer I is selected from At least one of them.

[0031] Preferably, monomer II is selected from one or more of dimethylaminoethyl dimethacrylate, diethylaminoethyl methacrylate, dimethylaminopropylacrylamide, diethylaminopropylacrylamide, dimethylaminopropylmethacrylamide, and diethylaminopropylmethacrylamide.

[0032] Preferably, the acrylamide monomer in monomer III is methacrylamide-2-hydroxymethyl ester or acrylamide-2-hydroxyethyl ester;

[0033] The polymerizable unsaturated monomer having an anion-donating group is selected from one or more of methacrylic acid, crotonic acid, maleic acid, taurine, vinyl sulfonic acid, styrene sulfonic acid, vinylbenzene sulfonic acid, acrylamide-tert-butyl sulfonic acid, and salts prepared from the above acids.

[0034] The acrylate monomer is an oxoalkylene-methacrylate monomer with the structure CH2=CX1C(=O)-O-(RO). n -X2 or CH2=CX1C(=O)-O-(RO) n -O-(O=)CX1C=CH2;

[0035] Wherein, X1 is selected from H atoms or methyl groups; X2 is selected from H atoms, saturated or unsaturated C1 to C2 atoms. 10 The hydrocarbon group; R is selected from C2 to C3 alkylene groups; n is selected from any integer from 1 to 20; more preferably, n is selected from any integer from 2 to 10;

[0036] The polymerizable unsaturated siloxane coupling agent is selected from one or more of γ-(methacryloyloxy)propyltrimethoxysilane, γ-(methacryloyloxy)propyltriethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, allyltrimethoxysilane, and allyltriethoxysilane.

[0037] The polyfunctional and polymerizable unsaturated monomer is selected from one or more of the following: trimethylolpropane triacrylate, pentaerythritol triacrylate, tetraethylene glycol diacrylate, tri(2-hydroxyethyl) isocyanurate diacrylate, tri(2-hydroxyethyl) isocyanurate dimethacrylate, tri(2-hydroxyethyl) isocyanurate triacrylate, and tri(2-hydroxyethyl) isocyanurate trimethacrylate.

[0038] The present invention also provides a composition comprising the copolymer described above and a solvent, wherein the solvent comprises water and / or an organic solvent.

[0039] Specifically, the organic solvent is a fatty hydrocarbon, an aromatic hydrocarbon, an ether, an ester, an alcohol or an organosiloxane oligomer.

[0040] Preferably, the fatty hydrocarbon is hexane, octane, decane or cyclohexane.

[0041] Preferably, the aromatic hydrocarbon is benzene, toluene or xylene.

[0042] Preferably, the ether is diethyl ether or dibutyl ether.

[0043] Preferably, the ester is methyl acetate, ethyl acetate, butyl acetate or isobutyl acetate.

[0044] Preferably, the alcohol is methanol, ethanol, isopropanol or butanol.

[0045] Preferably, the organosiloxane oligomer is octamethylcyclotetrasiloxane, decamethylcyclopentasiloxane, hexamethyldisiloxane or octamethyltrisiloxane.

[0046] The present application also relates to a preparation method of the composition, which specifically comprises the following steps:

[0047] S1. polymerizing the monomers in the organic solvent by free radical polymerization and ionic polymerization to obtain a copolymer solution;

[0048] S2. adding a hydrocarbonating agent to the copolymer solution to convert the tertiary amine in the copolymer into a quaternary ammonium salt through a quaternization reaction, thereby obtaining a quaternized copolymer solution;

[0049] S3. adding a cosolvent to the quaternized copolymer solution, and then adding water to disperse, thereby obtaining the composition.

[0050] Preferably, the free radical polymerization is carried out in the presence of a free radical initiator, which is one or more than two of azo type or organic peroxide type initiators.

[0051] Preferably, the azo type initiator is one or more than two of 2,2'-azobis(isobutyronitrile), 2,2'-azobis(2-methylbutyronitrile), 2,2'-azobis(2,4-dimethylvaleronitrile) and dimethyl-2,2'-azobis(2-methylpropanoate).

[0052] Preferably, the organic peroxide initiator is one or more than two of benzoyl peroxide, lauroyl peroxide, tert-butyl peroxybenzoate and tert-butyl peroxy-2-ethylhexanoate.

[0053] Preferably, the amount of the free radical initiator is 0.1-5 wt% of the total weight of all the monomers.

[0054] Specifically, the hydrophobating agent is selected from one or more of halogenated alkanes, chloromethylbenzene halogenated alkanes, dialkyl sulfate, alkylene oxide, and sulfonate hydrophobating agents.

[0055] Preferably, the halogenated alkanes are selected from one or more of methyl chloride, ethyl chloride, propyl chloride, butyl chloride, pentyl chloride, hexyl chloride, heptyl chloride, octyl chloride, nonyl chloride, decyl chloride, methyl bromide, ethyl bromide, propyl bromide, butyl bromide, pentyl bromide, hexyl bromide, heptyl bromide, octyl bromide, nonyl bromide, and decyl bromide.

[0056] Preferably, the dialkyl sulfate is dimethyl sulfate.

[0057] Preferably, the alkylene oxide is ethylene oxide.

[0058] Preferably, the sulfonate is methyl p-toluene sulfonate.

[0059] Preferably, the quaternization reaction is carried out in the presence of a catalyst. Specifically, the catalyst is selected from one or more of Lewis bases, soda ash, caustic soda, and iodide ions.

[0060] Preferably, the co-solvent is selected from one or more of acetic acid, formic acid, acetic acid, propionic acid, and benzoic acid.

[0061] Specifically, in step 3, the co-solvent can be added to the quaternized copolymer solution, and at least one of a surfactant, a dispersant, a high molecular coagulant, a retention aid, a film forming aid, an antioxidant, an antifoaming agent, an antifreeze agent, a flame retardant, and a reinforcing agent can be added to improve the stability of the aqueous dispersion and the wettability of the fiber product.

[0062] Preferably, the surfactant is selected from one or more of nonionic surfactants, cationic surfactants, anionic surfactants, and amphoteric surfactants.

[0063] More preferably, the surfactant is at least one of a nonionic surfactant and a cationic surfactant.

[0064] Preferably, the dispersant is a high molecular dispersant; more preferably, the high molecular dispersant is selected from one or more of styrene-maleic anhydride copolymer, polystyrene sulfonate, polyacrylic acid, polyacrylic acid salt, polyacrylamide, acrylamide-acrylic acid copolymer, polyvinyl alcohol, and carboxymethyl cellulose.

[0065] The present application also protects a paper treatment agent containing the above-mentioned aqueous dispersion type copolymer, composition, or composition prepared by the above-mentioned preparation method.

[0066] The present application also protects a paper and / or paper product prepared from the above-mentioned copolymer, the above-mentioned composition, the composition prepared by the above-mentioned preparation method, and / or the paper prepared by the above-mentioned paper treatment agent, comprising paper fibers and the above-mentioned water-dispersible copolymer, composition, composition prepared by the above-mentioned preparation method, or paper treatment agent.

[0067] Preferably, the paper fibers are sugar cane pulp fibers, bamboo pulp fibers, or wood pulp fibers.

[0068] Compared with the prior art, the present application has the following beneficial effects:

[0069] 1. The carbosiloxane dendritic monomer used in the present application is a molecular structure in which silicon atoms are arranged radially, and the carbosiloxane units extend in the form of dendrimers. It is this dendrimer structure that makes the copolymer and its composition obtained therefrom have stronger water and oil repellency than other linear and simply branched polysiloxanes.

[0070] 2. The copolymer and its composition obtained by quaternization are suitable for a wider pH environment, from acidic to alkaline, and show cationic properties, making the copolymer more easily combined with negatively charged fibers.

[0071] 3. Compared with the copolymer directly cationized by acid, the copolymer quaternary ammonium salt obtained by quaternization has better water and oil repellency. DETAILED DESCRIPTION

[0072] In order to more clearly and completely describe the technical solutions of the present application, the present application is further described in detail below through specific examples. It should be understood that the specific examples described herein are only used to explain the present application and are not used to limit the present application, and various changes can be made within the scope of the present application. BRIEF DESCRIPTION OF DRAWINGS

[0073] Fig. 1 and Fig. 2 are water and oil repellency test diagrams of paper plates prepared from the water-dispersible copolymer and its composition prepared by the embodiments and comparative examples of the present application

[0074] Example 1

[0075] The present example provides a preparation method of a water-dispersible copolymer and its composition, comprising the following steps:

[0076] S1. 50.0 g of isopropyl alcohol, 18.7 g of carbosiloxane dendrimer monomer I1-8, 4.74 g of ω-hydroxy-polyoxyethylene methacrylate of the formula CH2=C(CH3)-C(=O)-O-(CH2CH2O)5H were placed in a 250 ml four-necked flask equipped with a stirrer, thermometer and two 100 ml dropping funnels, and were bubbled with nitrogen to degas thoroughly, after which they were heated to 65°C; 0.3 g of AIBN initiator was dissolved in 20 g of isopropyl alcohol and placed in a 10 ml dropping funnel; the initiator solution was added dropwise from the dropping funnel to the flask maintained at 65°C over a period of 3 h under a nitrogen atmosphere; at the same time, 0.8 g of N-hydroxymethyl acrylamide, 5.76 g of dimethylaminoethyl methacrylate were mixed homogeneously and added dropwise from the dropping funnel to the flask over a period of 3 h; after the addition was complete, the mixture was maintained at 67°C under a nitrogen atmosphere and stirring was continued for 6 h;

[0077] S2. 3.96 g of chlorobutane was added dropwise from the dropping funnel to the mixture over a period of half an hour, and the reaction was stirred at 65°C overnight;

[0078] S3. To the above solution, 1.0 g of acetic acid and 50 g of water were added, and the mixture was stirred homogeneously to obtain a transparent aqueous dispersion solution; the aqueous dispersion copolymer was obtained, and the solid content was 19.78%.

[0079] Example 2

[0080] A method for preparing an aqueous dispersion copolymer and its composition, which is different from Example 1 in that:

[0081] The monomer I used in S1 is I1-7.

[0082] Example 3

[0083] A method for preparing an aqueous dispersion copolymer and its composition, which is different from Example 1 in that:

[0084] The carbosiloxane dendrimer monomer used in S1 is I1-9.

[0085] Example 4

[0086] A method for preparing an aqueous dispersion copolymer and its composition, which is different from Example 1 in that:

[0087] The monomer I used in S1 is I1-1, the mass of monomer I1-1 is 16.5 g, the mass of ω-hydroxy-polyoxyethylene methacrylate of the formula CH2=C(CH3)-C(=O)-O-(CH2CH2O)5H is 6.94 g, and the solid content of the obtained aqueous dispersion copolymer is 19.28%.

[0088] Example 5

[0089] A method for preparing a water-dispersible copolymer and its composition, which is different from that of Example 4 in that:

[0090] The monomer I used in S1 is I1-2.

[0091] Example 6

[0092] A method for preparing a water-dispersible copolymer and its composition, which is different from that of Example 4 in that:

[0093] The monomer I used in S1 is I1-3.

[0094] Comparative Example 1

[0095] A method for preparing a water-dispersible copolymer and its composition, which is different from that of Example 1 in that:

[0096] The monomer I used in S1 is Si-1000, with a molecular weight of 1000-1200 g / mol and a viscosity of 8-12 cst, and its structural formula is as follows:

[0097] Comparative Example 2

[0098] A method for preparing a water-dispersible copolymer and its composition, which is different from that of Example 1 in that:

[0099] There is no step S2, and 3.07 g of acetic acid is directly added for cationization, followed by the addition of water to obtain a water dispersion.

[0100] Comparative Example 3

[0101] A method for preparing a water-dispersible copolymer and its composition, which is different from that of Example 1 in that:

[0102] The monomer I used in S1 is Si-400, and its structural formula is as follows:

[0103] Performance Test

[0104] 1. Preparation of Paper Lunch Box

[0105] The raw sugar cane pulp is milled with a beater at a pulp consistency of about 3%, and a beating degree of 27SR. A quantity of the thick pulp corresponding to 15 g of absolute dry pulp is weighed, diluted with water to a consistency of 0.6%, and the prepared aqueous dispersion of the copolymer is added in an amount of 2.5% based on the absolute dry pulp, and stirred for 2 minutes. After a short rest, the mixture is poured into a mold, and a wet blank is formed under vacuum suction. The wet blank is then transferred to a drying mold, and dried under vacuum suction, with an upper mold temperature of 185°C, a lower mold temperature of 170°C, and a drying time of 45 seconds. A 8.86 inch circular plate is formed by vacuum pressing, and the plate has a thickness of 0.5 mm.

[0106] 2. Oil resistance test

[0107] 2-1. KIT test (oil resistance)

[0108] The paper plate is placed flat, and the test surface cannot be touched by hand. The test surface is upward, and a Kit Test standard reagent provided with castor oil, toluene, and heptane is dropped on the paper plate at a height of 25 mm. After 15 seconds, the remaining Kit Test standard reagent is wiped off with clean toilet paper, and the back of the oil droplet is immediately observed for discoloration due to penetration. If there is no penetration, the test passes, and a higher level test is performed until the Kit level test liquid is not penetrated and discolored. The oil resistance of the paper is the Kit level value, and the higher the Kit No. level, the better the oil resistance performance.

[0109] The Kit Test standard reagent is prepared according to the formulation in Table 1.

[0110] Table 1 Kit Test standard reagent formulation table

[0111] 2-2. Plate leakage evaluation of oil resistance level

[0112] Hot oil at a specified temperature is poured into the circular plate, and the test is performed for 30 minutes, and then the hot oil is poured out. The inner and outer surfaces of the plate bottom are observed, and the oil resistance level is evaluated according to the leakage.

[0113] Level 5 is no discoloration on the inner surface;

[0114] Level 4 is a small amount of discoloration on the inner surface, and no leakage on the outer surface;

[0115] Level 3 is a small amount of leakage on the outer surface;

[0116] Level 2 is an area of leakage on the outer surface less than 50%;

[0117] Level 1 is an area of leakage on the outer surface greater than 50%;

[0118] Level 0 is immediate leakage on the outer surface.

[0119] 3. Test for water resistance

[0120] Pour hot water at 95°C, which is close to boiling, into the tray and test for 30 minutes, then pour out the hot water. Observe whether the bottom of the tray leaks.

[0121] The performance test data are shown in Table 2, Figure 1 and Figure 2.

[0122] Table 2 Comparison of test performance results of Examples 1-6 and Comparative Examples 1-3

[0123] The copolymers synthesized using the carbosiloxane dendritic monomer of Examples 1-6 have good water resistance and oil resistance when used as paper treatment agents. No water leaks at 95°C; only a small amount of discoloration occurs on the inner surface when the oil temperature is 20-100°C, and no leakage occurs on the outer surface, with the oil resistance level being above Level 4, and the oil resistance levels of Examples 1 and 5 are both Level 5; the oil resistance levels of Examples 3, 4 and 6 are Level 4 only when the oil temperature is 100°C, and are Level 5 when the oil temperature is not higher than 50°C; the water-dispersible polymers of Examples 1-6 of the present application exhibit excellent oil resistance and water resistance.

[0124] From the results of Comparative Example 1 and Comparative Example 3, when the monomer I is the branched silicon monomer Si-1000 and Si-400, the oil resistance of the copolymers synthesized therefrom used as paper treatment agents is poor.

[0125] From the results of Comparative Example 2, when the copolymer is obtained by direct cationization with an organic acid without quaternary ammonium reaction and used as a paper treatment agent, the oil resistance is also poor.

[0126] Obviously, the above examples of the present application are merely illustrative for clearly explaining the present application, and are not intended to limit the embodiments of the present application. Other different forms of changes or variations can be made by those of ordinary skill in the art based on the above description. It is not necessary or possible to exhaust all embodiments. Any modification, equivalent replacement and improvement, etc. made within the spirit and principles of the present application shall be included in the protection scope of the claims of the present application.

Claims

1. A water-dispersible copolymer, characterized by: which comprises a repeating unit derived from monomer I, a repeating unit derived from monomer II, and a repeating unit derived from monomer III; The structural general formula of the monomer I is as follows: wherein X is a group bearing a carbon-carbon double bond; R 1 and R 2 each independently is C1-C 10 alkyl, C1-C 10 aryl or C1-C 10 aralkyl, and a is any one of 0, 1, 2. L represents a hydrogen atom, C1 to C2 atoms. 10 Alkyl groups, C1-C 10 Aryl, C1~C 10 Aryl or silyl groups, or structures as follows: wherein Y is an alkylene group, and p is an integer of 1 to 10; R 3 and R 4 each independently is C1-C 10 alkyl, C1-C 10 aryl or C1-C 10 aralkyl, b is any of 0, 1, 2; M is a hydrogen atom, C1~C 10 Alkyl, C1-C 10 Aryl, C1~C 10 Aryl or silyl groups; The structural formula of the monomer II is as follows: wherein R is H or C1-C4alkyl; and 5 10 alkyl; and​ Z is N or O; Q is a tertiary amine-containing organic group; the monomer III is selected from one or two or more of an acrylate-based monomer, an acrylamide-based monomer, a polymerizable unsaturated monomer having an anion-supplying group which is a carboxyl group or a sulfonic acid group, a polymerizable unsaturated siloxane coupling agent, and a polymerizable unsaturated monomer containing a polyfunctional group selected from one or two or more of a hydroxyl group, an isocyanurate group, an ester group, and an ether group.

2. The copolymer of claim 1, wherein The repeating unit derived from monomer I, the repeating unit derived from monomer II, and the repeating unit derived from monomer III are present in a mass ratio of 20 to 85 wt% : 10 to 40 wt% : 0 to 40 wt%.

3. The copolymer according to claim 1, wherein In monomer I, R 1 and R 2 each independently is methyl; and / or; X is selected from at least one of an organic group containing an acryloyl group or a methacryloyl group, an organic group containing an alkenyl group and an aryl group, and an alkenyl group having 2 to 10 carbon atoms; and / or in L, M is a methyl group or an ethyl group; and / or In monomer II, R 5 is H or methyl.

4. The copolymer according to any one of claims 1 to 3, wherein said monomer I is selected from at least one of 5. The copolymer according to any one of claims 1 to 3, wherein the monomer II is selected from one or two or more of dimethylaminoethyl dimethyl acrylate, diethylaminoethyl methacrylate, dimethylaminopropyl acrylamide, diethylaminopropyl acrylamide, dimethylaminopropyl methacrylamide, and diethylaminopropyl methacrylamide.

6. The copolymer according to any one of claims 1 to 3, wherein in the monomer III, the acrylamide-based monomer is selected from methacrylamide-2-hydroxy methyl ester or acrylamide-2-hydroxy-ethyl ester; the polymerizable unsaturated monomer having an anion-supplying group is selected from one or two or more of methacrylic acid, crotonic acid, maleic acid, itaconic acid, vinyl sulfonic acid, styrene sulfonic acid, vinyl benzene sulfonic acid, and acrylamide-tert-butyl sulfonic acid, and a salt of the above acids; the polymerizable unsaturated siloxane coupling agent is selected from one or two or more of γ-(methacryloyloxy)propyl trimethoxysilane, γ-(methacryloyloxy)propyl triethoxysilane, vinyl trimethoxysilane, vinyl triethoxysilane, and allyl trimethoxysilane and allyl triethoxysilane; said acrylate monomer is selected from the group consisting of oxyalkylene-methacrylate monomers having the structure CH2=CX1C(=O)-O-(RO) n X2or CH2=CX1C(=O)-O-(RO) n O-(O=)CX1C=CH2; wherein X1is a H atom or a methyl group; X2is a H atom, a saturated or unsaturated C1-C 10 hydrocarbon group; R is a C2-C3 alkylene group; n is an integer from 1 to 20; n is preferably from 2 to 10; the polymerizable unsaturated monomer containing a polyfunctional group is selected from one or two or more of trimethylolpropane triacrylate, pentaerythritol triacrylate, tetraethylene glycol diacrylate, tris(2-hydroxyethyl) isocyanurate diacrylate, tris(2-hydroxyethyl) isocyanurate dimethacrylate, tris(2-hydroxyethyl) isocyanurate triacrylate, and tris(2-hydroxyethyl) isocyanurate trimethacrylate.

7. A composition comprising the copolymer according to any one of claims 1 to 6 and a solvent, the solvent including water and / or an organic solvent. ​ 8. A method for preparing the composition of claim 7, comprising the following steps: S1. polymerizing the monomers by free radical polymerization and ionic polymerization in an organic solvent in the presence of an initiator to obtain a copolymer solution; S2. adding a hydrocarbylating agent to the copolymer solution to convert the tertiary amine in the copolymer into a quaternary ammonium salt by a quaternization reaction to obtain a quaternized copolymer solution; S3. adding a cosolvent to the quaternized copolymer solution, and then adding water to disperse the solution to obtain the composition.

9. A paper treatment agent comprising the copolymer of any one of claims 1-6, the composition of claim 7, or the composition prepared by the method of claim 8.

10. Paper and / or paper products prepared from the copolymer of any one of claims 1-6, the composition of claim 7, the composition prepared by the method of claim 8, or the paper treatment agent of claim 9. ​ ​ ​

Images