Biphenyl skeleton-containing bisphosphate functional monomer, and preparation method and application thereof

Abstract

The present application relates to a bisphosphate functional monomer containing a biphenyl skeleton, a preparation method and application thereof, and belongs to the technical field of emulsion polymerization. The phosphate functional monomer has the following general structure formula (I), wherein R 1 is H or CH3, R 2 is -C(O)-O- or -O-, m and n are independently any natural number from 1 to 10, and R is an aromatic or heteroaromatic group having two phenolic hydroxyl groups. The bisphosphate functional monomer can be used to prepare a metal anticorrosion emulsion, and a coating layer is formed on a metal substrate through emulsion polymerization, which can significantly improve the adhesion and salt spray resistance of the coating layer.

Description

Technical Field

[0001] This invention relates to the field of emulsion polymerization technology, and more specifically, to a rigid-framework-based bisphosphate functional monomer, its preparation method, and its application in the preparation of aqueous emulsions. Background Technology

[0002] Emulsion polymerization is an important method for preparing waterborne coatings and is widely used in fields such as metal substrate protection. To improve the adhesion of emulsions to metal substrates, phosphate ester functional monomers are often introduced. The phosphate ester groups can form coordination chelates with metal ions, thereby enhancing the adhesion between the coating and the metal substrate.

[0003] Currently, monophosphate functional monomers are widely used, but because they contain only one phosphate group and have a single chelation site, there is room for improvement in coating performance. Coatings formed by applying such functional monomers to emulsions have problems such as weak adhesion and poor corrosion resistance.

[0004] Therefore, there is an urgent need in this field to develop a novel phosphate ester functional monomer to improve the adhesion of coatings formed by emulsion polymerization to metal substrates, as well as the salt spray resistance of the coatings. Summary of the Invention

[0005] To address the aforementioned problems in the existing technology, the present invention provides a bisphosphate functional monomer that can improve coating adhesion and salt spray resistance.

[0006] In a first aspect of the present invention, a diphosphate functional monomer is provided, having the following general structural formula (I):

[0007] (I)

[0008] Among them, R 1 For H or CH3, R 2 For -C(O)-O- or -O, m and n are any natural numbers from 1 to 10;

[0009] R is selected from one of the following groups:

[0010] Wherein, X is H, CH3, F, Cl, or Br;

[0011] Wherein, X is H, CH3, F, Cl, or Br;

[0012] Wherein, X is H, CH3, F, Cl, or Br;

[0013] Wherein, X is H, CH3, F, Cl, or Br;

[0014] Wherein, X is H, CH3, F, Cl, or Br;

[0015] Wherein, X is H, CH3, F, Cl, or Br;

[0016] Wherein, X is H, CH3, F, Cl, or Br;

[0017] Where X is H, CH3, F, Cl or Br.

[0018] In some embodiments of the first aspect of the invention, m and n in formula (I) are independently taken from any natural number from 1 to 5; preferably, m and n are independently taken from any natural number from 1 to 3; more preferably, m and n are both 1.

[0019] In some embodiments of the first aspect of the invention, R in formula (I) is selected from one of the following groups:

[0020] , , , or .

[0021] In some embodiments of the first aspect of the present invention, the bisphosphate functional monomer of formula (I) has the following structural formula:

[0022] ,

[0023] ,

[0024] ,

[0025] or

[0026] .

[0027] In a second aspect of the invention, an intermediate compound for preparing the bisphosphophosphate functional monomer of the invention is provided, having the following general structural formula (II):

[0028] (II)

[0029] Among them, R 1 For H or CH3, R 2 For -C(O)-O- or -O, m and n are independently taken from any natural number from 1 to 10;

[0030] R is selected from one of the following groups:

[0031] Wherein, X is H, CH3, F, Cl, or Br;

[0032] Wherein, X is H, CH3, F, Cl, or Br;

[0033] Wherein, X is H, CH3, F, Cl, or Br;

[0034] Wherein, X is H, CH3, F, Cl, or Br;

[0035] Wherein, X is H, CH3, F, Cl, or Br;

[0036] Wherein, X is H, CH3, F, Cl, or Br;

[0037] Wherein, X is H, CH3, F, Cl, or Br;

[0038] Where X is H, CH3, F, Cl or Br.

[0039] In some embodiments of the second aspect of the invention, m and n in formula (II) are independently taken from any natural number from 1 to 5; preferably, m and n are independently taken from any natural number from 1 to 3; more preferably, m and n are both 1.

[0040] In some embodiments of the second aspect of the invention, R in formula (II) is selected from one of the following groups:

[0041] , , , or .

[0042] In some embodiments of the second aspect of the invention, the intermediate compound of formula (II) has the following structural formula:

[0043] ,

[0044] ,

[0045] ,

[0046] or

[0047] .

[0048] In a third aspect of the invention, a method for preparing the bisphosphophosphate functional monomer of the invention is provided, comprising the following steps:

[0049] (a) Epoxy ring-opening reaction:

[0050] Aromatic or heteroaromatic compounds with two phenolic hydroxyl groups are reacted with olefinic unsaturated monomers containing epoxy groups in the presence of a catalyst to form intermediate compounds with general structural formula (II).

[0051] The aromatic or heteroaromatic compound having two phenolic hydroxyl groups is selected from one of the following compounds:

[0052] Wherein, X is H, CH3, F, Cl, or Br;

[0053] Wherein, X is H, CH3, F, Cl, or Br;

[0054] Wherein, X is H, CH3, F, Cl, or Br;

[0055] Wherein, X is H, CH3, F, Cl, or Br;

[0056] Wherein, X is H, CH3, F, Cl, or Br;

[0057] Wherein, X is H, CH3, F, Cl, or Br;

[0058] Wherein, X is H, CH3, F, Cl, or Br;

[0059] Wherein, X is H, CH3, F, Cl, or Br;

[0060] The structure of the epoxy-containing olefinic unsaturated monomer is shown in formula (III):

[0061] (III)

[0062] In equation (III), R 1 For H or CH3, R 2 For -C(O)-O- or -O, m and n are independently taken from any natural number from 1 to 10.

[0063] (b) Phosphorylation reaction:

[0064] The intermediate compound of general formula (II) obtained in step (a) is subjected to phosphorylation to form a bisphosphoester functional monomer with the structure of general formula (I).

[0065] In some embodiments of the third aspect of the invention, the aromatic or heteroaromatic compound having two phenolic hydroxyl groups has one of the following structural formulas:

[0066] , , , , , , , , .

[0067] In some embodiments of the third aspect of the invention, m and n in formula (III) are independently taken from any natural number from 1 to 5; preferably, m and n are independently taken from any natural number from 1 to 3; more preferably, m and n are both 1.

[0068] In some embodiments of the third aspect of the invention, the epoxy-containing olefinic unsaturated monomer has one of the following structural formulas:

[0069] , , , , , , , .

[0070] In a fourth aspect of the invention, the use of the bisphosphate functional monomer according to the first aspect of the invention in the preparation of metal corrosion-preserving emulsions is provided.

[0071] In a fifth aspect of the invention, a metal corrosion-preserving emulsion is provided, said emulsion being prepared using the bisphosphate functional monomer described in the first aspect of the invention.

[0072] In some embodiments of the fifth aspect of the present invention, the metal corrosion-resistant emulsion is an acrylate emulsion and its copolymer emulsion, an organosilicon-modified emulsion, or a vinyl emulsion.

[0073] In a sixth aspect of the invention, a method for forming a coating on a metal substrate is provided, the method employing a coating formulated with a metal anti-corrosion emulsion according to a fifth aspect of the invention.

[0074] Compared with the prior art, the present invention has the following advantages:

[0075] (1) The present invention provides a bisphosphonate functional monomer with an innovative structure. The functional monomer has a biphenyl skeleton or naphthalene ring, an anthracene ring or its heterocyclic analog skeleton, a bisphosphonate group and a diene bond end-capped structure. Therefore, the bisphosphonate functional monomer of the present invention has a rigid skeleton, double chelate sites and high reactivity. When it is used to form a coating on a metal substrate by emulsion polymerization, it can significantly improve the coating adhesion and salt spray resistance, and improve mechanical strength.

[0076] (2) This invention relates to an innovation in the synthesis process of diphosphate functional monomers. Specifically, the preparation method of diphosphate functional monomers of this invention is achieved through a two-step reaction of epoxy ring-opening and phosphorylation. The process is feasible and further realizes the innovation of the synthesis process of diphosphate. Specifically, the one-step synthesis of diphosphate functional monomers is achieved through a single-step condensation-phosphorylation tandem reaction. Compared with the multi-step reaction path that usually requires phenolic hydroxyl protection, phosphorylation and deprotection in the prior art, this invention significantly reduces the reaction steps, improves the overall yield and reduces the production cost. Attached Figure Description

[0077] Figure 1 The nuclear magnetic resonance hydrogen spectrum of intermediate product 1 prepared according to Example 1 of the present invention ( 1 H NMR).

[0078] Figure 2 The proton nuclear magnetic resonance spectrum of product 1 prepared according to Example 1 of the present invention (… 1 H NMR).

[0079] Figure 3 The phosphorus nuclear magnetic resonance spectrum of product 1 prepared according to Example 1 of the present invention ( 31 P NMR).

[0080] Figure 4 The nuclear magnetic resonance hydrogen spectrum of intermediate product 2 prepared according to Example 2 of the present invention ( 1 H NMR).

[0081] Figure 5 The nuclear magnetic resonance hydrogen spectrum of product 2 prepared according to Example 2 of the present invention ( 1 H NMR).

[0082] Figure 6 The phosphorus nuclear magnetic resonance spectrum of product 2 prepared according to Example 2 of the present invention ( 31 P NMR).

[0083] Figure 7 The nuclear magnetic resonance hydrogen spectrum of intermediate product 3 prepared according to Example 3 of the present invention ( 1 H NMR).

[0084] Figure 8 The nuclear magnetic resonance hydrogen spectrum of product 3 prepared according to Example 3 of the present invention ( 1 H NMR).

[0085] Figure 9 The phosphorus nuclear magnetic resonance spectrum of product 3 prepared according to Example 3 of the present invention ( 31 P NMR).

[0086] Figure 10 The nuclear magnetic resonance hydrogen spectrum of intermediate product 4 prepared according to Example 4 of the present invention ( 1 H NMR).

[0087] Figure 11 The proton nuclear magnetic resonance spectrum of product 4 prepared according to Example 4 of the present invention ( 1 H NMR).

[0088] Figure 12 The phosphorus nuclear magnetic resonance spectrum of product 4 prepared according to Example 4 of the present invention ( 31 P NMR).

[0089] Figure 13 The nuclear magnetic resonance hydrogen spectrum of intermediate product 5 prepared according to Example 5 of the present invention ( 1 H NMR).

[0090] Figure 14 The proton nuclear magnetic resonance spectrum of product 5 prepared according to Example 5 of the present invention (… 1 H NMR).

[0091] Figure 15 The phosphorus nuclear magnetic resonance spectrum of product 5 prepared according to Example 5 of the present invention ( 31 P NMR). Detailed Implementation

[0092] The following detailed description of various aspects of the present invention will be provided in conjunction with specific embodiments. These specific embodiments are only for illustrating the present invention and do not constitute a limitation on the scope and substance of the present invention.

[0093] In the structural design of the bisphosphate functional monomer shown in formula (I) of the present invention, a rigid skeleton containing aromatic or heteroaromatic groups is selected, and epoxy groups containing olefin bonds are connected to both ends through an epoxy ring-opening reaction, and bisphosphate groups are introduced through phosphorylation.

[0094] The rigid framework in the bisphosphate functional monomer structure of the present invention restricts the spatial orientation of the bisphosphate groups, forming a double chelate structure, thereby achieving efficient chelation of metal substrates.

[0095] The rigid skeleton in the bisphosphate functional monomer structure of the present invention includes a divalent aromatic or heteroaromatic linking group, which may be selected from: 4,4'-biphenyl, 3,3'-dimethyl-4,4'-biphenyl, 2,2'-difluoro-4,4'-biphenyl, 5,8-dihydroxyquinoline, 2,4-dihydroxyquinoline, 2,8-dihydroxyquinoline, 6-fluoro-2,4-dihydroxyquinoline, 1,5-dihydroxynaphthyl, 2,3-dihydroxynaphthyl, 4,7-dihydroxybenzo[d]thiophene, etc.

[0096] In the bisphosphate functional monomer structure of the present invention, end groups with olefinic unsaturated groups are introduced at both ends through an epoxy ring-opening reaction. The olefinic unsaturated groups can be selected from: -CH2-CH(OH)-CH2-OC(O)-CH=CH2 derived from acryloyloxy (-CH2=CH-C(O)O-) epoxy ring-opening, -CH2-CH(OH)-CH2-OC(O)-C(CH3)=CH2 derived from methacryloyloxy (-CH2=C(CH3)-C(O)O-) epoxy ring-opening, -CH2-CH(OH)-CH2-O-CH2-CH=CH2 derived from allyloxy (-CH2=CH-CH2-O-) epoxy ring-opening, -CH2-CH(OH)-CH2-O-CH2-C(CH3)=CH2 derived from methallyloxy (-CH2=C(CH3)-CH2-O-) epoxy ring-opening, etc. This double-bond, double-end design enables monomers to participate in emulsion polymerization crosslinking, forming a dense network structure that significantly improves the material's mechanical strength and thermal stability.

[0097] In the bisphosphate functional monomer structure of the present invention, the hydroxyl group provides a double chelating site, which can enhance the chemical bonding with the metal substrate.

[0098] In the bisphosphate functional monomers of this invention, the rigid framework optimizes the geometric matching degree (such as bond distance / bond angle) of its chelating sites by fixing the spatial configuration of the bisphosphate groups, thus adapting to the coordination requirements of the target metal ions. Simultaneously, the cross-linked network formed by the monomer anchors the chelating groups to the polymer matrix and regulates its microenvironment and accessibility. These two aspects synergistically enhance the chelating ability and stability of interfacial metal ions, thereby improving the coating's adhesion, corrosion inhibition, and other protective properties.

[0099] In the bisphosphate functional monomer structure of the present invention, an olefinic unsaturated monomer containing an epoxy group (such as glycidyl acrylate, glycidyl methacrylate, or allyl glycidyl ether) is selected, and the corrosion resistance or interfacial compatibility of the phosphate group is further optimized by reacting its epoxy group with the phosphate group.

[0100] The preparation of the bisphosphoester functional monomer of the present invention includes an epoxy ring-opening reaction and a phosphorylation reaction. In the epoxy ring-opening reaction, the reactants are an aromatic or heteroaromatic compound having two phenolic hydroxyl groups and one or two molecules of an olefinically unsaturated monomer containing an epoxy group. In the presence of a catalyst, the phenolic hydroxyl groups undergo nucleophilic ring-opening of the epoxy group to obtain a bisepoxy ring-opening intermediate containing an aromatic or heteroaromatic rigid skeleton with olefinically unsaturated ends. In the phosphorylation reaction, the intermediate is reacted with a phosphorylating agent to phosphorylate the two hydroxyl groups (-OH) in its molecule, thereby introducing two phosphate ester groups into the molecule to obtain the target bisphosphoester functional monomer.

[0101] In the preparation of the bisphosphate functional monomer of the present invention, the aromatic or heteroaromatic compound having two phenolic hydroxyl groups used as the reactant can be selected from: 4,4'-biphenyl, 3,3'-dimethyl-4,4'-biphenyl, 2,2'-difluoro-4,4'-biphenyl, 5,8-dihydroxyquinoline, 2,4-dihydroxyquinoline, 2,8-dihydroxyquinoline, 6-fluoro-2,4-dihydroxyquinoline, 1,5-dihydroxynaphthalene, 2,3-dihydroxynaphthalene, 4,7-dihydroxybenzo[d]thiophene, etc., or derivatives of the above compounds substituted with 1 to 3 independent substituents selected from halogens or alkyl groups.

[0102] In the preparation of the bisphosphoester functional monomer of the present invention, the epoxy-containing olefinic unsaturated monomer used as the reaction raw material has an end group of olefinic unsaturated group and can be selected from compounds containing acryloyloxy (CH2=CH-C(O)O-), compounds containing methacryloyloxy (CH2=C(CH3)-C(O)O-), or compounds containing allyloxy (CH2=CH-CH2-O-), such as glycidyl esters containing acryloyloxy or methacryloyloxy or glycidyl ethers containing allyloxy.

[0103] In the preparation method of the bisphosphate functional monomer of the present invention, the catalyst used for the epoxy ring-opening reaction includes one or more of the following catalysts: tertiary amine, quaternary ammonium salt, boron trifluoride or its ether complex salt, aluminum chloride, barium oxide, tin tetrachloride, sodium hydroxide, potassium hydroxide, etc.

[0104] In the preparation method of the bisphosphoester functional monomer of the present invention, the phosphorylation reagent used in the phosphorylation reaction includes one or more of the following reagents: phosphorus oxychloride, phosphorus pentoxide, phosphoric acid, or polyphosphoric acid (PPA).

[0105] The intermediate compound generated by the ring-opening reaction of epoxy was obtained by drying and purification by vacuum distillation.

[0106] The bisphosphate functional monomer of the present invention can be used as a functional comonomer for the synthesis of aqueous polymeric emulsions, such as metal corrosion-resistant emulsions. It is suitable for the preparation of emulsions containing the following systems, such as acrylates and their copolymer emulsions, silicone-modified emulsions, vinyl emulsions, and inorganic-organic hybrid emulsions.

[0107] Emulsions prepared using the bisphosphate functional monomers of the present invention can be used to form coatings on the surface of metal substrates, and their applications can be extended to metal surface treatment, anti-corrosion coatings, electronic packaging and other fields.

[0108] The following description, through examples, further details the bisphosphophosphate functional monomers of the present invention, their preparation methods, and their applications.

[0109] Example 1

[0110] The synthetic route for the bisphosphophosphate functional monomer in this embodiment is as follows:

[0111]

[0112] 4,4'-Bisphenol A (48 g, 0.26 mol) and 100 mL of 1,4-dioxane were added to a dry 500 mL three-necked flask. Under nitrogen protection, 1.2 g of tin tetrachloride was added as a catalyst. The system was heated to 80 °C and stirred until the solid was completely dissolved. Glycidyl acrylate (65 g, 0.57 mol) was added, and the reaction was continued at 80 °C with stirring for 3 hours. After the reaction was complete, the mixture was cooled to room temperature, and the reaction was quenched with 2 mL of methanol. The white precipitate was collected by filtration. The filter cake was washed thoroughly with 3 × 50 mL of dichloromethane (filtered after each wash). All filtrates and washings were combined and distilled under reduced pressure (20 kPa, 50 °C) to remove dichloromethane and low-boiling impurities. The residue was dried in a drying oven to give intermediate product 1, which was a colorless crystal (yield 92%). 1 ¹H NMR characterization confirmed that the chemical structure of intermediate 1 is 3,3'-[4,4'-biphenyldioxy]bis[1-allyloxy-2-propanol]. 1 H NMR spectrum as shown Figure 1 As shown. 1H NMR (600 MHz, CDCl3) δ 7.59– 7.53 (m, 4H), 6.88 – 6.81 (m, 4H), 5.91 – 5.79 (m, 2H), 5.22 (dtt, J =11.9, 2.0, 0.9 Hz, 2H), 5.06 (dtt, J = 11.9, 2.0, 1.1 Hz, 2H), 4.21 (p, J =5.6 Hz, 2H), 4.09 (dd, J = 11.4, 5.7 Hz, 2H), 4.00 (dd, J = 11.4, 5.6 Hz, 2H), 3.95 (dt, J = 6.2, 0.9 Hz, 4H), 3.59 (dd, J = 11.4, 5.5 Hz, 2H), 3.46(dd, J = 11.3, 5.5 Hz, 2H).

[0113] Intermediate product 1 (50 g, 0.12 mol) was placed in a dry 500 mL three-necked flask and heated to 80 °C, maintaining the temperature constant. Phosphorus oxychloride (POCl3, 38 g, 0.25 mol) was slowly added dropwise through a constant-pressure dropping funnel, controlling the dropping rate to complete the addition within 1 hour. After the addition was complete, the reaction mixture was stirred at 80 °C for 3 hours. The system was then heated to 90 °C, and deionized water (0.8 g, 0.044 mol) was slowly added through a micro-syringe under vigorous stirring, controlling the water addition rate to avoid localized overheating. After the addition was complete, the mixture was refluxed at 90 °C for 24 hours. After cooling the reaction solution to room temperature, product 1 was finally obtained as a yellowish-brown crystalline solid (yield 98%). The structure of product 1 was determined by… 1 H NMR and 31 P NMR characterization confirmed it as 4,4'-biphenyldioxybis[3-allyloxypropane-1,2-diyl]bis(dihydrogen phosphate), and the specific characterization results are as follows:

[0114] 1H NMR (600 MHz, CDCl3) δ 7.59 – 7.53 (m, 4H), 6.88 – 6.81 (m, 4H), 5.91 – 5.79 (m, 2H), 5.22 (dtt, J = 11.9, 2.0, 0.9 Hz, 2H), 5.06 (dtt, J =11.9, 2.0, 1.1 Hz, 2H), 4.21 (p, J = 5.6 Hz, 2H), 4.09 (dd, J = 11.4, 5.7 Hz, 2H), 4.00 (dd, J = 11.4, 5.6 Hz, 2H), 3.95 (dt, J = 6.2, 0.9 Hz, 4H), 3.59(dd, J = 11.4, 5.5 Hz, 2H), 3.46 (dd, J = 11.3, 5.5 Hz, 2H). Correspondingly 1 H NMR spectrum as shown Figure 2 As shown.

[0115] 31 P NMR (600 MHz, CDCl3) δ 1.98 (s, 2P). Correspondingly 31 p NMR spectrum as shown Figure 3 As shown.

[0116] Example 2

[0117] The synthetic route for the bisphosphophosphate functional monomer in this embodiment is as follows:

[0118]

[0119] 55.5 g (0.25 mol) of 2,2'-difluoro-4,4'-biphenylhydroquinone and 100 mL of 1,4-dioxane were added to a dry 500 mL three-necked flask. Sodium hydroxide (1.4 g) was added as a catalyst under nitrogen protection. The system was heated to 120 °C and stirred until the solid was completely dissolved. Glycidyl methacrylate (81 g, 0.57 mol) was then added, and the reaction was continued at 120 °C with stirring for 3.5 hours. After the reaction was complete, the mixture was cooled to room temperature, and 2 mL of methanol was added to quench the reaction. The white precipitate was collected by filtration. The filter cake was washed thoroughly with 3 × 50 mL of dichloromethane (filtered after each wash). All filtrates and washings were combined and distilled under reduced pressure (20 kPa, 50 °C) to remove dichloromethane and low-boiling impurities. The residue was dried to obtain intermediate product 2, a colorless crystal (yield 87%). Its structure was determined by... 1¹H NMR characterization confirmed its chemical structure as 4,4'-bis[(2-hydroxypropane-1,3-diyl)oxy]-2,2'-difluorobiphenylbis(2-methacrylate). 1 HNMR spectrum as follows Figure 4 As shown. 1 H NMR (600 MHz, CDCl3) δ 7.28 – 7.21 (m, 2H), 6.99 (dd, J =8.4, 1.8 Hz, 1H), 6.82 (dd, J = 8.0, 1.9 Hz, 2H), 6.75 (dd, J = 8.4, 2.0 Hz, 1H), 6.31 (ddq, J = 15.0, 2.0, 0.9 Hz, 2H), 5.89 (ddq, J = 15.0, 2.0, 0.9 Hz, 2H), 4.50 – 4.41 (m, 4H), 4.32 – 4.24 (m, 2H), 4.13 (dd, J = 11.5, 5.3 Hz,2H), 4.09 – 4.01 (m, 2H), 1.92 (t, J = 1.0 Hz, 6H).

[0120] Intermediate product 2 (60.8 g, 0.12 mol) was added to a dry 500 mL three-necked flask. The mixture was heated to 75 °C and maintained at a constant temperature. Phosphorus pentoxide (P₂O₅, 35.5 g, 0.25 mol) was added in three portions over one hour using a screw feeder, and the reaction was maintained for 3 hours. The system was then heated to 90 °C, and 0.8 g of deionized water was slowly added for hydrolysis. Stirring continued for 24 hours. After cooling the reaction solution to room temperature, product 2 was obtained as a yellow-brown crystalline solid (97% yield). The structure of product 2 was determined by... 1 H NMR and 31 P NMR characterization confirmed it to be 4,4'-bis{[2-(phosphooxy)propane-1,3-diyl]oxy}-2,2'-difluorobiphenylbis(2-methacrylate), and the specific characterization results are as follows:

[0121] 1H NMR (600 MHz, CDCl3) δ 7.41 (ddd, J = 8.4, 5.0, 2.0 Hz, 2H), 6.84 (dd, J = 8.0, 1.9 Hz, 2H), 6.76 (dd, J = 8.4, 1.9 Hz, 2H), 6.33 (ddq, J =15.0, 2.0, 0.9 Hz, 2H), 5.90 (ddq, J = 15.0, 2.0, 0.9 Hz, 2H), 5.11 (dp, J =8.1, 5.6 Hz, 2H), 4.64 (dd, J = 11.3, 5.6 Hz, 2H), 4.45 (dd, J = 11.3, 5.6Hz, 2H), 4.29 (dd, J = 11.4, 5.6 Hz, 2H), 4.22 (dd, J = 11.4, 5.6 Hz, 2H), 1.94 (t, J = 1.0 Hz, 6H). Correspondingly... 1 H NMR spectrum as shown Figure 5 As shown.

[0122] 31 P NMR (600 MHz, CDCl3) δ 2.08 (s, 2P). Correspondingly 31 p NMR spectrum as shown Figure 6 As shown.

[0123] Example 3

[0124] The synthetic route for the bisphosphophosphate functional monomer in this embodiment is as follows:

[0125]

[0126] 1,5-Dihydroxynaphthalene (45 g, 0.28 mol) and 100 mL of 1,4-dioxane were added to a dry 500 mL three-necked flask. Boron trifluoride diethyl ether (BF3•Et2O, 0.9 g) was added as a catalyst under nitrogen protection. The system was heated to 40 °C and stirred until the solid was completely dissolved. Glycidyl methacrylate (81 g, 0.57 mol) was then added, and the reaction was continued at 400 °C with stirring for 4 hours. After the reaction was complete, the mixture was cooled to room temperature, and the reaction was quenched with 2 mL of methanol. The white precipitate was collected by filtration. The filter cake was washed thoroughly with 3 × 50 mL of dichloromethane (filtered after each wash). All filtrates and washings were combined and distilled under reduced pressure (20 kPa, 50 °C) to remove dichloromethane and low-boiling impurities. The residue was dried in a drying oven to obtain intermediate product 3, a colorless crystal (yield 85%). Its chemical structure was determined by...1 ¹H NMR characterization confirmed it to be (1,5-naphthyldioxy)bis(3-hydroxy-1,3-propanediyl)bis(2-methacrylate). 1 H NMR spectrum as shown Figure 7 As shown. 1 H NMR (600MHz, CDCl3) δ 7.88 (dt, J = 7.8, 0.7 Hz, 2H), 7.38 (t, J = 7.8 Hz, 2H), 7.09– 7.03 (m, 2H), 6.31 (ddq, J = 2.0, 0.9, 0.2 Hz, 2H), 5.89 (ddq, J = 15.0,2.0, 0.9 Hz, 2H), 4.49 – 4.42 (m, 4H), 4.32 – 4.25 (m, 2H), 4.19 – 4.12 (m,2H), 4.15 – 4.04 (m, 2H), 1.92 (t, J = 1.0 Hz, 6H).

[0127] Intermediate product 3 (53.3 g, 0.12 mol) was added to a dry 500 mL three-necked reaction vessel. The system temperature was maintained at 85 °C, and phosphoric acid (H3PO4, 35.5 g, 0.25 mol) was slowly added dropwise over 1 hour, maintaining the reaction for 3 hours. Subsequently, the system was heated to 85 °C, and 0.8 g of deionized water was slowly added for hydrolysis. Stirring continued for 24 hours. After cooling the reaction solution to room temperature, product 3 was obtained as a yellow-brown crystalline solid (96% yield). The structure of product 3 was determined by... 1 H NMR and 31 P NMR characterization confirmed it to be 1,5-bis[3-(2-methacryloyloxy)-2-phosphooxypropoxy]naphthalene, and the specific characterization results are as follows:

[0128] 1H NMR (600 MHz, CDCl3) δ 7.80 (dt, J = 7.9, 0.7 Hz, 2H), 7.47 (t, J =7.9 Hz, 1H), 7.38 (t, J = 7.9 Hz, 1H), 7.09 – 7.03 (m, 2H), 6.31 (ddq, J =15.0, 2.0, 0.9 Hz, 2H), 5.89 (ddq, J = 15.0, 2.0, 0.9 Hz, 2H), 5.10 (dp, J =8.2, 5.6 Hz, 2H), 4.61 (dd, J = 11.3, 5.6 Hz, 2H), 4.43 (dd, J = 11.3, 5.6Hz, 2H), 4.30 (dd, J = 11.4, 5.6 Hz, 2H), 4.23 (dd, J = 11.4, 5.6 Hz, 2H), 1.92 (t, J = 1.0 Hz, 6H). Correspondingly... 1 H NMR spectrum as shown Figure 8 As shown.

[0129] 31 P NMR (600 MHz, CDCl3) δ 2.23 (s, 2P). Correspondingly... 31 p NMR spectrum as shown Figure 9 As shown.

[0130] Example 4

[0131] The synthetic route for the bisphosphophosphate functional monomer in this embodiment is as follows:

[0132]

[0133] 4,7-Dihydroxybenzo[d]thiophene (46.5 g, 0.28 mol) and 100 mL of 1,4-dioxane were added to a dry 500 mL three-necked flask. Boron trifluoride diethyl ether (BF3•Et2O, 0.9 g) was added as a catalyst under nitrogen protection. The system was heated to 40 °C and stirred until the solid was completely dissolved. Glycidyl methacrylate (81 g, 0.57 mol) was then added, and the reaction was continued at 400 °C with stirring for 4 hours. After the reaction was complete, the mixture was cooled to room temperature, and the reaction was quenched with 2 mL of methanol. The white precipitate was collected by filtration. The filter cake was washed thoroughly with 3 × 50 mL of dichloromethane (filtered after each wash). All filtrates and washings were combined and distilled under reduced pressure (20 kPa, 50 °C) to remove dichloromethane and low-boiling impurities. The residue was dried to obtain intermediate product 4, a colorless crystal (yield 87%). Its chemical structure was determined by... 1 ¹H NMR characterization confirmed it to be 4,7-bis(2-methacryloyloxy-3-hydroxypropoxy)benzo[b]thiophene. 1 H NMR spectrum as shown Figure 10 As shown. 1 HNMR (600 MHz, CDCl3) δ 7.47 (d, J = 6.1 Hz, 1H), 7.37 (d, J = 6.0 Hz, 1H), 6.88 (d, J = 8.4 Hz, 1H), 6.80 (d, J = 8.5 Hz, 1H), 6.31 (ddq, J = 15.4, 2.0,0.9 Hz, 2H), 5.89 (ddq, J = 14.6, 2.0, 0.9 Hz, 2H), 4.51 – 4.42 (m, 4H), 4.32– 4.25 (m, 2H), 4.20 – 4.11 (m, 2H), 4.14 – 4.04 (m, 2H), 1.92 (t, J = 1.0Hz, 8H).

[0134] Intermediate product 4 (54.1 g, 0.12 mol) was added to a dry 500 mL three-necked reaction vessel. The system temperature was maintained at 85 °C, and phosphoric acid (H3PO4, 35.5 g, 0.25 mol) was slowly added dropwise over 1 hour, maintaining the reaction for 3 hours. Subsequently, the system was heated to 85 °C, and 0.8 g of deionized water was slowly added for hydrolysis. Stirring continued for 24 hours. After cooling the reaction solution to room temperature, product 4 was obtained as a brown crystalline solid (95% yield). The structure of product 4 was determined by... 1 H NMR and 31P NMR characterization confirmed it to be bis(methacryloyloxy-3-phosphate glycerol ether benzothiophene), and the specific characterization results are as follows:

[0135] 1 H NMR (600 MHz, CDCl3) δ 7.46 (d, J = 6.2 Hz, 1H), 7.30 (d, J = 6.2Hz, 1H), 6.91 – 6.83 (m, 2H), 6.31 (ddq, J = 15.4, 2.0, 0.9 Hz, 2H), 5.89(ddq, J = 14.6, 2.0, 0.9 Hz, 2H), 5.15 – 5.04 (m, 2H), 4.61 (dd, J = 11.2,5.5 Hz, 2H), 4.43 (dd, J = 11.3, 5.6 Hz, 2H), 4.30 (dd, J = 11.4, 5.6 Hz,2H), 4.23 (dd, J = 11.4, 5.5 Hz, 2H), 1.92 (t, J = 1.0 Hz, 6H). Correspondingly 1 H NMR spectrum as shown Figure 11 As shown.

[0136] 31 P NMR (600 MHz, CDCl3) δ 1.97 (s, 2P). Correspondingly 31 p NMR spectrum as shown Figure 12 As shown.

[0137] Example 5

[0138] The synthetic route for the bisphosphophosphate functional monomer in this embodiment is as follows:

[0139]

[0140] 5,8-Dihydroxyquinoline (45 g, 0.28 mol) and 100 mL of 1,4-dioxane were added to a dry 500 mL three-necked flask. Boron trifluoride diethyl ether (BF3•Et2O, 0.9 g) was added as a catalyst under nitrogen protection. The system was heated to 40 °C and stirred until the solid was completely dissolved. Glycidyl methacrylate (81 g, 0.57 mol) was then added, and the reaction was continued at 400 °C with stirring for 4 hours. After the reaction was complete, the mixture was cooled to room temperature, and the reaction was quenched with 2 mL of methanol. The white precipitate was collected by filtration. The filter cake was washed thoroughly with 3 × 50 mL of dichloromethane (filtered after each wash). All filtrates and washings were combined and distilled under reduced pressure (20 kPa, 50 °C) to remove dichloromethane and low-boiling impurities. The residue was dried in a drying oven to obtain intermediate product 5, a colorless crystal (yield 82%). 1 ¹H NMR confirmed its chemical structure as 5,8-bis(2-methacryloyloxy-3-hydroxypropoxy)quinoline, and its structure 1 H NMR spectrum as shown Figure 13 As shown. 1 H NMR (600 MHz, CDCl3) δ 8.61 (dd, J = 3.5, 2.2 Hz, 1H), 8.45 (dd, J = 7.7, 2.2 Hz, 1H), 7.29 (dd, J = 7.9, 3.5 Hz, 1H), 7.11 (d, J = 8.4 Hz, 1H), 6.94 (d, J = 8.4 Hz,1H), 6.31 (ddq, J = 15.4, 2.0, 0.9 Hz, 2H), 5.89 (ddq, J = 14.6, 2.0, 0.9 Hz,2H), 4.51 – 4.42 (m, 4H), 4.32 – 4.22 (m, 3H), 4.19 – 4.12 (m, 1H), 4.12 –4.04 (m, 1H), 3.79 – 3.70 (m, 1H), 1.92 (d, J = 0.9 Hz, 6H).

[0141] Intermediate product 5 (53.5 g, 0.12 mol) was added to a dry 500 mL three-necked reaction vessel. The system temperature was maintained at 85 °C. PPA (115%, 84.5 g, 0.25 mol) was slowly added dropwise in three portions over one hour, and the reaction was maintained for 3 hours. The system was then heated to 85 °C, and 0.8 g of deionized water was slowly added for hydrolysis. Stirring continued for 24 hours. After cooling the reaction solution to room temperature, product 5 was obtained as a brown crystalline solid (97% yield). The structure of product 5 was determined by…1 H NMR and 31 P NMR characterization confirmed it to be bis(methacryloyloxy-3-phosphate glycerol ether quinoline, and the specific characterization results are as follows:

[0142] 1 H NMR (600 MHz, CDCl3) δ 8.63 (dd, J = 3.5, 2.2 Hz, 1H), 7.53 (dd, J= 7.8, 2.2 Hz, 1H), 7.36 – 7.28 (m, 2H), 7.26 (d, J = 8.4 Hz, 1H), 6.33 (ddq,J = 15.4, 2.0, 0.9 Hz, 2H), 5.90 (ddq, J = 14.6, 2.0, 0.9 Hz, 2H), 5.16 –5.06 (m, 2H), 4.63 (dd, J = 11.3, 5.6 Hz, 2H), 4.44 (ddd, J = 11.4, 9.5, 5.4Hz, 3H), 4.39 – 4.29 (m, 2H), 4.25 (dd, J = 11.4, 5.6 Hz, 1H), 1.94 (t, J = 1.0 Hz, 6H). Correspondingly 1 H NMR spectrum as shown Figure 14 As shown.

[0143] 31 P NMR (600 MHz, CDCl3) δ 1.97 (s, 2P). Correspondingly 31 p NMR spectrum as shown Figure 15 As shown.

[0144] Application Examples

[0145] To evaluate the performance of the bisphosphate functional monomers prepared in Examples 1-5 in metal anti-corrosion coatings, these application examples compare the monomers of these examples with the commercially available polyphosphate monomer PAM-200. The emulsions and coatings were prepared according to the following steps:

[0146] 1. emulsion synthesis

[0147] (1) Preparation of base solution: Add butyl acrylate (45 g), styrene (15 g), deionized water (75 g) and ammonium persulfate (0.9 g) to a 500 mL reactor and stir at 300 rpm until homogeneous.

[0148] (2) Pre-emulsification: 60 g of butyl acrylate, 30 g of styrene, 150 g of deionized water, 0.85 g of emulsifier SR-10 and 3 g of target functional monomer were mixed and homogenized at high speed (10,000 rpm, 10 min) to obtain a stable pre-emulsion.

[0149] (3) Emulsion polymerization:

[0150] The base solution was heated to 85°C. After the system emitted a bluish glow, the pre-emulsion was added dropwise at a uniform rate (completed within 2 hours). The mixture was then heated to 90°C and matured for 1 hour. After cooling to 25°C, it was filtered (200 mesh) to obtain an acrylic emulsion containing bisphosphonate monomers. A total of 6 emulsions were prepared, using the bisphosphonate functional monomers prepared in Examples 1-5 and PAM-200, respectively.

[0151] 2. Preparation of anti-corrosion coatings

[0152] Take 100 g of each of the above emulsions, and add dispersant BYK-190 (2 g), wetting agent TEGO-4100 (0.5 g), defoamer BYK-1711 (0.5 g), and anti-flash rust agent Halox Flash-X150 (0.5 g) in sequence. After stirring at low speed (500 rpm, 10 min), add titanium dioxide R-706 (20 g) and iron oxide red pigment (5 g), and disperse at high speed (2000 rpm, 15 min). Finally, add thickener ACRYSOL RM-8W (1 g) and adjust the viscosity to 100±5 KU (tested with a Stormer viscometer) to obtain 6 kinds of anti-corrosion coatings.

[0153] 3. Coating preparation

[0154] (1) Substrate treatment: Sandblast Q235 carbon steel plate (size 150×70×1 mm), clean and dry.

[0155] (2) Spraying process:

[0156] Using a SATA jet 5000 automatic spray gun, the compressed air supply pressure was adjusted to 0.4 MPa, maintaining a vertical distance of 20 cm between the spray gun nozzle and the substrate surface. During spraying, the spray gun should be moved smoothly and at a constant distance. The dry film thickness after multiple coats was controlled to be 50 ± 2 μm by adjusting the gun speed and spray width overlap. The dry film thickness was measured using an eddy current thickness gauge after curing. The coated samples were placed in a standard laboratory environment (temperature: 23 ± 2°C, relative humidity: 50 ± 10%) for 7 days (168 hours) for room temperature curing. After 7 days of curing, the coating's adhesion and corrosion resistance were tested according to relevant testing standards.

[0157] 4. Comparative Testing

[0158] (1) Coating adhesion test:

[0159] For the coatings formed using the bisphosphate functional monomers prepared in Examples 1-5 and the emulsion prepared using PAM200 as a comparative example in the application examples, the coating adhesion was tested according to standard GB / T 9286-2021 (Cross-cut test for paint and varnish films). A multi-bladed cutting tool with a blade spacing of 1 mm, a blade angle of 30°, and a hardness ≥ HRC 55 was used. The auxiliary material was adhesive tape with a width of 25 mm and an adhesive strength of (10±1) N / 25 mm. After cutting a grid with a specified spacing on the coating surface, the center of the tape was placed above the grid area, and the tape was pressed firmly with a finger to ensure complete adhesion. It was left to stand for (90±30) seconds. Subsequently, the tape was peeled off smoothly and quickly at an angle close to 60° within (0.5~1.0) seconds. Immediately after peeling off the tape, the coating peeling in the grid area was observed under suitable lighting conditions using a magnifying glass (e.g., 2~3x). The test results are shown in Table 1.

[0160] Table 1

[0161]

[0162] Observation revealed that coatings formulated with emulsions prepared using the bisphosphate functional monomers of Examples 1-5 exhibited no paint film peeling in the cross-cut areas. According to the GB / T 9286-2021 standard, all coatings achieved the highest adhesion grade, level 0 (completely smooth cut edges, no peeling within the grid). In contrast, the coating formed with the emulsion obtained from Comparative Example PAM200 showed coating peeling at the cut intersections and along the cut edges, with the affected cross-cut area exceeding 5% but not exceeding 15%, resulting in a test grade of 2. This demonstrates that the coatings formed using the functional monomers of this invention exhibit significantly superior adhesion compared to Comparative Example PAM200.

[0163] (2) Salt spray resistance test of coating:

[0164] For the coatings formed by the emulsions obtained from the bisphosphate functional monomers prepared in Examples 1-5 and the comparative example PAM200 in the application examples, the salt spray resistance of each coating was evaluated according to the standard GB / T 1771-2007 (Determination of the resistance of paints and varnishes to neutral salt spray). Specifically, two 50 mm long intersecting lines (angle 30°-60°) were scratched on the coating surface with a tungsten carbide scalpel tip, reaching the exposed metal substrate, with a scratch spacing ≥25 mm. The scratched sample was placed in a salt spray chamber at 35±1℃ and sprayed with a 5% NaCl solution at pH 6.8 (sedimentation rate 1.5 mL / (h·80 cm²)). The sample was tilted at an angle of 20±5° (relative to the vertical direction) and tested continuously for 1000 h. The scratch penetration width (microscopic measurement, accuracy ±0.1 mm), corrosion grade (Ri, according to GB / T 30789.3-2014) and blistering grade (GB / T 1766-2008) were recorded at 48-h intervals. The test results are shown in Table 2.

[0165] Table 2

[0166]

[0167] As shown in Table 2, the coatings formulated with emulsions prepared using the bisphosphonate functional monomers of Examples 1-5 of this invention exhibit a corrosion diffusion width of 0.6-1.2 mm and a corrosion grade of Ri1-Ri3. In contrast, PAM-200 has a corrosion diffusion width >3.0 mm and a corrosion grade of Ri5, with dense blistering at grade S4 on the surface. This indicates that the coatings formed using the bisphosphonate functional monomers of this invention have significantly better salt spray resistance than the comparative example PAM200.

[0168] The present invention has been specifically described above with reference to specific embodiments. These specific embodiments are merely exemplary and should not be construed as limiting the scope of protection of the present invention. Those skilled in the art can make various modifications, changes, or substitutions to the present invention without departing from its spirit and scope. Therefore, various equivalent variations made in accordance with the present invention still fall within the scope of the present invention.

Claims

1. A bisphosphonate functional monomer containing a biphenyl skeleton, having the following general structure (I), ###0001### (I) wherein, R is selected from one of the following groups: ###0002### （I） wherein R 1 is H or CH3, R 2 is -C(O)-O- or -O, m and n are independently taken from any natural number from 1 to 10; m and n are independently selected from any natural number from 1 to 5. wherein X is H, CH3, F, CI or Br; wherein X is H, CH3, F, CI or Br; wherein X is H, CH3, F, CI or Br; wherein X is H, CH3, F, CI or Br; wherein X is H, CH3, F, CI or Br; wherein X is H, CH3, F, CI or Br; wherein X is H, CH3, F, CI or Br; wherein X is H, CH3, F, CI or Br.

2. The bisphosphonate functional monomer of claim 1, wherein, R is selected from one of the following groups: ###0003### 3. The bisphosphonate functional monomer of claim 1, wherein, 4. The bisphosphonate functional monomer of claim 1, having the following structure: ###0004### , , , or .

5. A method for preparing the bisphosphonate functional monomer of claim 1, comprising the following steps: (a) an epoxy ring-opening reaction: subjecting an aromatic or heteroaromatic compound having two phenolic hydroxyl groups to a nucleophilic ring-opening reaction with an epoxy-containing ethylenically unsaturated monomer in the presence of a catalyst to form an intermediate compound having the general structure (II); ###0005### (II) wherein, the aromatic or heteroaromatic compound having two phenolic hydroxyl groups is selected from one of the following compounds: ###0006### wherein, the structure of the epoxy-containing ethylenically unsaturated monomer is shown in formula (III): ###0007### (III) wherein, the general structure (II) is as follows: ###0008### 、 、 、 or 。 R is selected from one of the following groups: ###0009### (b) a phosphonation reaction: subjecting the intermediate compound of general structure (II) obtained in step (a) to a phosphonation reaction to form the bisphosphonate functional monomer having the structure of general formula (I). the aromatic or heteroaromatic compound having two phenolic hydroxyl groups has one of the following structures: ###0010### the epoxy-containing ethylenically unsaturated monomer has one of the following structures: ###0011### 8. Use of the bisphosphonate functional monomer of any one of claims 1 to 4 in the preparation of a metal anticorrosion emulsion. wherein X is H, CH3, F, CI or Br; wherein X is H, CH3, F, CI or Br; wherein X is H, CH3, F, CI or Br; wherein X is H, CH3, F, CI or Br; wherein X is H, CH3, F, CI or Br; wherein X is H, CH3, F, CI or Br; wherein X is H, CH3, F, CI or Br; wherein X is H, CH3, F, CI or Br; 9. A metal anticorrosion emulsion prepared using the bisphosphonate functional monomer of any one of claims 1 to 4. (III) In formula (III), R 1 is H or CH3, R 2 is -C(O)-O- or -O, m and n are independently taken from any natural number from 1 to 10; 10. The metal anticorrosion emulsion of claim 9, wherein the emulsion is an acrylate and its copolymer emulsion, a silicone-modified emulsion, or a vinyl-based emulsion. (I) wherein R 1 is H or CH3, R 2 is -C(O)-O- or -O, m and n are independently taken from any natural number from 1 to 10; 11. A method for forming a coating on a metal substrate using a coating prepared using the metal anticorrosion emulsion of claim 9 or 10. wherein X is H, CH3, F, CI or Br; wherein X is H, CH3, F, CI or Br; wherein X is H, CH3, F, CI or Br; wherein X is H, CH3, F, CI or Br; wherein X is H, CH3, F, CI or Br; wherein X is H, CH3, F, CI or Br; wherein X is H, CH3, F, CI or Br; wherein X is H, CH3, F, CI or Br; ​ ​ 6. The production method according to claim 5, wherein ​ 、 、 、 、 、 、 、 、 。 7. The production method according to claim 5, wherein ​ 、 、 、 、 、 、 、 。 ​ ​ ​ ​

Images