Epoxy pipe dope for cast iron pipes and fittings for building drainage and method of making same

Abstract

The present application belongs to the technical field of paint preparation, and particularly relates to an epoxy pipeline paint for cast iron pipes and cast iron fittings for building drainage and a preparation method thereof. Caffeic acid and alcohol amine are reacted in the presence of tetrahydrofuran and N,N-dimethylformamide to obtain a caffeic acid-based amide, then epoxy chloropropane is added, and an epoxy resin viscous substance is prepared through polycondensation reaction, and the obtained epoxy resin viscous substance is diluted and mixed with organic ketone-modified organic amine, pigments and fillers, high-molecular additives and solvents to obtain the pipeline paint. The present application uses bio-based caffeic acid as raw material, which is widely available and easy to obtain, and has the advantages of environmental protection and low price. The addition of organic ketone-modified organic amine as a curing agent not only has high curing reactivity, but also significantly improves the storage stability. The prepared paint has excellent durability and adhesion, and high peeling strength, which greatly improves the service life of the material.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of paint preparation, and particularly relates to an epoxy pipeline paint for cast iron pipes and cast iron fittings for building drainage and a preparation method thereof. BACKGROUND

[0002] As a high-performance polymer, epoxy resin is widely used in the fields of electronic packaging, protective coating, carbon fiber composite material, etc. due to its excellent adhesion, heat resistance, chemical stability and mechanical properties. Epoxy resin has strong adhesion to inorganic materials such as cement and metal due to its strong polarity ether group and hydroxyl group, and has excellent corrosion resistance, wear resistance, impact resistance and mechanical properties. It is mainly used in floor coating, automobile primer, metal corrosion protection, chemical corrosion protection and other aspects. In the long run, epoxy pipeline paint coating is the future development trend.

[0003] The existing epoxy pipeline paint mainly includes epoxy primer, epoxy topcoat, epoxy intermediate paint, epoxy coal tar paint, epoxy phenolic paint, epoxy glass flake paint, epoxy rust-resistant paint, epoxy zinc phosphate primer and epoxy floor paint, but it usually has problems such as poor compatibility and unstable mechanics. SUMMARY

[0004] The present application provides an epoxy pipeline paint and a preparation method thereof to solve the instability of traditional epoxy pipeline paint. The epoxy resin is synthesized by using bio-based caffeic acid as a functional raw material. The caffeic acid is first functionalized into an amide derivative, and then condensed with epoxy chloropropane to form the required epoxy resin viscous substance. The obtained epoxy resin viscous substance is mixed and diluted with a solvent (N,N-dimethylformamide) to obtain a suitable viscosity, and then an organic ketone modified amine curing agent, a pigment filler, a polymer additive and a solvent are added before use as an epoxy pipeline paint.

[0005] The preparation method of the epoxy pipeline paint provided by the present application has the following specific steps:

[0006] (1) Synthesis of caffeic acid amide

[0007] The caffeic acid is taken in a double-necked round-bottom flask, tetrahydrofuran and N,N-dimethylformamide are added under N2 atmosphere, and a condenser is provided. Alcohol amine is added dropwise in the flask, heated at 85℃ for 4h, after the reaction is completed, the solvent is removed as much as possible by using a rotary evaporator to obtain the required product (viscous liquid).

[0008] The alcohol amine is:

[0009] The molar ratio of caffeic acid to alcohol amine is 1:1.

[0010] (2) Preparation of epoxy resin viscous mass

[0011] In a two-necked round bottom flask equipped with a mechanical stirrer, the above-synthesized amide was taken and to it was added epichlorohydrin, KOH was added through a pressure equalizing funnel at 70°C, the rate of addition was maintained such that the pH of the solution was within 7.0. After the addition was complete, the resin mixture was heated at 80°C for another 2 h with continuous stirring. After cooling to room temperature, the product was transferred to a separating funnel and the two layers (aqueous and organic) were separated. The organic layer was washed several times with brine solution and distilled water to remove the impurities and unreacted reactants. Subsequently, tetrahydrofuran was added to the organic layer to dissolve the epoxy resin. Finally, tetrahydrofuran and water along with epichlorohydrin were removed by a rotary evaporator to obtain the desired epoxy resin viscous mass.

[0012] The epichlorohydrin monomer used was:

[0013] The molar ratio of caffeic acid based amide to epichlorohydrin was 1:2.

[0014] (3) Dilution of epoxy resin viscous mass

[0015] The epoxy resin viscous mass obtained was diluted with a solvent (N, N-dimethylformamide) to obtain a suitable viscosity for the next step.

[0016] (4) Preparation of epoxy pipeline paint

[0017] For use, the diluted epoxy resin was mixed with an organic ketone modified organic amine curing agent, pigments and fillers, polymeric adjuvants and a solvent to obtain the epoxy pipeline paint.

[0018] The method of organic ketone modified organic amine was: in a single necked flask, organic ketone, organic amine, sodium hydroxide and N, N-dimethylformamide were added and heated to 70°C, the reaction was carried out for 12 h, after completion of the reaction, the product was dried in an oven at 60°C for 24 h.

[0019] The organic ketone used was:

[0020] The organic amine used was:

[0021]

[0022] The molar ratio of organic ketone to organic amine was 1:1.

[0023] The amount of organic ketone modified organic amine added was 8% to 15% of the total mass of the diluted epoxy resin.

[0024] The color filler is talc, and the amount is 6-10% of the mass of the organic ketone modified organic amine curing agent.

[0025] The polymer auxiliary agent is p-hydroxybenzoic acid ester, and the amount is 3-8% of the mass of the organic ketone modified organic amine curing agent.

[0026] The solvent is N,N-dimethylformamide.

[0027] The organic ketone modified amine compound has high curing reactivity and obvious storage stability.

[0028] Beneficial effects:

[0029] The coffee acid and alcohol amine have synergistic effect, which can enhance the tensile strength and adhesion of the epoxy pipeline paint coating material, and the coffee acid is used as raw material, which is environment-friendly and non-toxic, and the raw material is easy to obtain.

[0030] The epoxy pipeline paint prepared by the method is environment-friendly and has high stability. BRIEF DESCRIPTION OF DRAWINGS

[0031] Figure 1 The infrared spectrum of the cured epoxy pipeline paint prepared in Example 1.

[0032] Figure 2 The thermogravimetric curve (TG) of the cured epoxy pipeline paint prepared in Example 1.

[0033] Figure 3 The thermogravimetric differential curve (DTG) of the cured epoxy pipeline paint prepared in Example 1. DETAILED DESCRIPTION

[0034] The application will be further described below in combination with examples, but is not limited thereto.

[0035] Example 1

[0036] The coffee acid (2g, 11.08mmol) was taken in a double-necked round-bottom flask, and tetrahydrofuran (2mL) and N,N-dimethylformamide (0.5mL) were added under N2 atmosphere, and a condenser was equipped. Diethanolamine (1.16g, 11.08mmol) was added dropwise in the flask, and heated at 85℃ for 4h. After the reaction was completed, the solvent was removed as much as possible by a rotary evaporator to obtain the desired product (thick liquid).

[0037] In a two necked round bottom flask equipped with a mechanical stirrer, the synthesized amide (1 g, 5.54 mmol) was taken into which epichlorohydrin (0.87 mL, 11.08 mmol) was added, KOH was added drop wise through a pressure equalizing funnel at 70 °C maintaining the drop wise addition rate such that the pH of the solution was maintained at 7.0. After the addition was complete, the resin mixture was heated at 80 °C for an additional 2 h with continuous stirring. After cooling to room temperature, the product was transferred to a separation funnel and the two layers (aqueous and organic) were separated. The organic layer was washed three times with brine solution and distilled water to remove the impurities and unreacted reactants. Subsequently, tetrahydrofuran was added to the organic layer to dissolve the epoxy resin. Finally, tetrahydrofuran and water along with epichlorohydrin were removed by a rotary evaporator to obtain the desired epoxy resin as a viscous mass.

[0038] The epoxy resin viscous mass obtained was taken 15 g and mixed with 50 mL of solvent (N, N-dimethylformamide) to obtain a suitable viscosity (500-600 mPa.s) for the next step.

[0039] In a single necked flask, 19.6 g of 2-methylbenzophenone, 6 g of ethylenediamine, 1.04 g of sodium hydroxide and 50 mL of N, N-dimethylformamide were taken and heated to 70 °C for 12 h. After completion of the reaction, the product was dried in an oven at 60 °C for 24 h to obtain 2-methylbenzophenone modified ethylenediamine.

[0040] In a flask, 10 g of the diluted epoxy resin, 0.83 g of 2-methylbenzophenone modified ethylenediamine, 0.07 g of talc, 0.04 g of p-hydroxybenzoic acid ester, 20 mL of N, N-dimethylformamide were taken and mixed with stirring to obtain the epoxy resin pipe dope.

[0041] To verify the mechanical properties of the pipe dope, the dope was poured into dumbbell shaped moulds and dried at room temperature for 5 h. The product so obtained was tested for tensile testing as per ASTM D882 at a testing speed of 500 mm / min. The tensile strength was found to be 20.25 MPa and the elongation at break was found to be 104%.

[0042] To verify the adhesive strength of the pipe dope, the pipe dope so obtained was poured into shear moulds and tested for shear testing as per ASTM D882 at a testing speed of 500 mm / min. The adhesive strength was found to be 3187.6 MPa.

[0043] To verify the chemical resistance of the pipeline paint, the pipeline paint material dried at room temperature for 5h was placed in NaOH (5%), HC1 (5%), NaCl (10%), ethanol (10%), H2O, and other different chemical media, respectively, and placed at room temperature for 30 days. The weight loss rates were recorded as NaOH (3.02%), HC1 (2.13%), NaCl (0.32%), ethanol (0.34%), and H2O (0%).

[0044] To verify the moisture resistance of the pipeline paint, the pipeline paint material dried at room temperature for 5h was subjected to a "double 85" test, and the test body was subjected to aging test under the condition that the environment was set to a temperature of 85°C and a humidity of 85%. The test time was 1000 hours, and then the limit that the coating material could withstand in the harsh environment of high temperature and high humidity was verified. Then, the material was placed in NaOH (5%), HC1 (5%), NaCl (10%), ethanol (10%), H2O, and other different chemical media, respectively, and placed at room temperature for 30 days. The weight loss rates were recorded as NaOH (3.12%), HC1 (2.43%), NaCl (0.38%), ethanol (0.42%), and H2O (0%).

[0045] To verify the impact resistance of the pipeline paint, the pipeline paint material dried at room temperature for 5h was subjected to impact strength performance test using ASTM D256 instrument. The impact strength of the material reached 24.3kJ / m 2 .

[0046] To verify the wear resistance of the pipeline paint, the obtained pipeline paint was uniformly coated on the surface of cast iron with a thickness of about 8mm. The coating material was subjected to 1h of friction by ball-on-disc friction method, and then the mass was weighed. The obtained mass was 1.9998g.

[0047] To verify the heat resistance of the pipeline paint, 10mg of the obtained pipeline paint material was heated at a rate of 10°C / min, and the temperature range was 30-800°C. The thermal decomposition temperature at which the sample lost 5% of its mass was 289°C, and the thermal decomposition temperature at which the sample lost 10% of its mass was 322°C.

[0048] Example 2

[0049] Coffee acid (2g, 11.08mmol) was taken in a two-necked round-bottom flask, and tetrahydrofuran (2mL) and N,N-dimethylformamide (0.5mL) were added under N2atmosphere, and a condenser was provided. Diethanolamine (1.16g, 11.08mmol) was added dropwise in the flask, and heated at 85°C for 4h. After the reaction was completed, the solvent was removed as much as possible using a rotary evaporator to obtain the desired product (a viscous liquid).

[0050] In a two necked round bottom flask equipped with a mechanical stirrer, 1 g (5.54 mmol) of the synthesized amide was taken and to this epoxy chloropropane (0.87 mL, 11.08 mmol) was added, KOH was added drop wise through a pressure equalizing funnel at 70°C, the rate of addition was maintained such that the pH of the solution was within 7.0. After the addition was complete, the resin mixture was heated at 80°C for another 2 h and stirring was continued. After cooling to room temperature, the product was transferred to a separation funnel and the two layers (aqueous and organic) were separated. The organic layer was washed with brine solution and distilled water several times to remove the impurities and unreacted reactants. Subsequently, tetrahydrofuran was added to the organic layer to dissolve the epoxy resin. Finally, tetrahydrofuran and water along with the epoxy chloropropane were removed by a rotary evaporator to get the desired epoxy resin as a viscous mass.

[0051] The epoxy resin viscous mass obtained was taken 15 g and mixed with 50 mL of solvent (N,N-dimethylformamide) to get the desired viscosity (500-600 mPa.s) for the next step.

[0052] In a single necked flask, 18.2 g of benzophenone, 6 g of ethylene diamine, 1.04 g of sodium hydroxide and 50 mL of N,N-dimethylformamide were taken and heated to 70°C and the reaction was carried out for 12 h. After completion of the reaction, the product was dried in an oven at 60°C for 24 h to get benzophenone modified ethylene diamine.

[0053] In a flask, 10 g of the diluted epoxy resin, 0.83 g of benzophenone modified ethylene diamine, 0.07 g of talc, 0.04 g of p-hydroxy benzoic acid ester and 20 mL of N,N-dimethylformamide were taken and mixed with stirring to get the desired epoxy resin pipe dope.

[0054] The performance test methods were same as in Example 1, the tensile strength was 18.78 MPa, the elongation at break was 84%, the adhesive strength was 2756.6 MPa, the chemical resistance, the weight loss was 3.12% in NaOH, 2.56% in HCl, 0.36% in NaCl, 0.37% in ethanol and 0% in H2O respectively, the wet heat resistance, the weight loss was 3.16% in NaOH, 2.76% in HCl, 0.43% in NaCl, 0.46% in ethanol and 0% in H2O respectively, the impact strength of the material was 20.4 kJ / m2, the mass after abrasion was 1.9993 g, the thermal decomposition temperature at 5% weight loss of the sample was 265°C and at 10% weight loss was 293°C. 2

[0055] Example 3

[0056] ​Take caffeic acid (2 g, 11.08 mmol) in a double-necked round-bottom flask, add tetrahydrofuran (2 mL) and N, N-dimethylformamide (0.5 mL) under N2 atmosphere, and equip with a condenser. Drop diethanolamine (1.16 g, 11.08 mmol) into the flask, heat at 85°C for 4 h, after the reaction is completed, remove the solvent as much as possible with a rotary evaporator to obtain the desired product (thick liquid).

[0057] Take (1 g, 5.54 mmol) synthesized amide in a double-necked round-bottom flask equipped with a mechanical stirrer, add epichlorohydrin (0.87 mL, 11.08 mmol) thereto, drop KOH through a pressure balance funnel at 70°C, and keep the drop rate within 7.0 of the solution pH value. After the addition is completed, continue heating the resin mixture at 80°C for 2 h and continue stirring. After cooling to room temperature, transfer the product to a separation funnel, separate the two layers (water layer and organic layer). Wash the organic layer with a saline solution and distilled water several times to remove impurities and unreacted reactants. Subsequently, add tetrahydrofuran to dissolve the epoxy resin in the organic layer. Finally, remove tetrahydrofuran and water together with epichlorohydrin through a rotary evaporator to obtain the desired epoxy resin thick substance.

[0058] Take 15 g of the obtained epoxy resin thick substance and mix with 50 ml of solvent (N, N-dimethylformamide) to obtain a suitable viscosity (500-600 mPa.s) for use in the next step.

[0059] Add 25.8 g of 4-phenylbenzophenone, 6 g of ethylenediamine, 1.04 g of sodium hydroxide, and 50 mL of N, N-dimethylformamide in a single-necked flask, and heat to 70°C for 12 h. After the reaction is completed, dry the product in an oven at 60°C for 24 h to obtain 4-phenylbenzophenone-modified ethylenediamine.

[0060] Add 10 g of diluted epoxy resin, 0.83 g of 4-phenylbenzophenone-modified ethylenediamine, 0.07 g of talc, 0.04 g of p-hydroxybenzoic acid ester, and 20 mL of N, N-dimethylformamide in a flask, mix by stirring to obtain the desired epoxy resin pipeline paint.

[0061] The performance test method is the same as in Example 1, the tensile strength is 18.23 MPa, the elongation at break is 93%, the adhesive strength is 3107.3 MPa, the chemical resistance, the weight loss rates are NaOH (3.34%), HCl (2.56%), NaCl (0.42%), ethanol (0.43%), and H2O (0%), respectively; the wet heat resistance, the weight loss rates are NaOH (3.45%), HCl (2.74%), NaCl (0.48%), ethanol (0.48%), and H2O (0%), respectively; the impact strength of the material reaches 19.7 kJ / m 2; the mass after rubbing is 1.9983 g; the thermal decomposition temperature at which the sample loses 5% of its mass is 275°C, and the thermal decomposition temperature at which the sample loses 10% of its mass is 307°C.

[0062] Example 4

[0063] Take caffeic acid (2 g, 11.08 mmol) in a double-necked round-bottom flask, add tetrahydrofuran (2 mL) and N,N-dimethylformamide (0.5 mL) under N2atmosphere, and equip with a condenser. Drop ethyl alcohol amine (0.99 g, 11.08 mmol) into the flask, heat at 85°C for 4 h, after the reaction is completed, remove the solvent as much as possible with a rotary evaporator to obtain the desired product (thick liquid).

[0064] Take (1 g, 5.54 mmol) of the synthesized amide in a double-necked round-bottom flask equipped with a mechanical stirrer, add epichlorohydrin (0.87 mL, 11.08 mmol) to it, and drop KOH through a pressure balance funnel at 70°C, keeping the drop rate within the pH value of the solution 7.0. After the addition is complete, continue heating the resin mixture at 80°C for 2 h and continue stirring. After cooling to room temperature, transfer the product to a separation funnel and separate the two layers (water layer and organic layer). Wash the organic layer with a saline solution and distilled water several times to remove impurities and unreacted reactants. Subsequently, add tetrahydrofuran to dissolve the epoxy resin in the organic layer. Finally, remove tetrahydrofuran and water together with epichlorohydrin through a rotary evaporator to obtain the desired epoxy resin thickener.

[0065] Take 15 g of the obtained epoxy resin thickener and mix with 50 ml of solvent (N,N-dimethylformamide) to obtain a suitable viscosity (500-600 mPa.s) for use in the next step.

[0066] Add 20.4 g of 1-hydroxycyclohexyl phenone, 6 g of ethylenediamine, 1.04 g of sodium hydroxide, and 50 mL of N,N-dimethylformamide to a single-neck flask, and heat to 70°C for 12 h. After the reaction is complete, dry the product in an oven at 60°C for 24 h to obtain 1-hydroxycyclohexyl phenone-modified ethylenediamine.

[0067] Add 10 g of the diluted epoxy resin, 0.83 g of 1-hydroxycyclohexyl phenone-modified ethylenediamine, 0.07 g of talc, 0.04 g of p-hydroxybenzoic acid ester, and 20 mL of N,N-dimethylformamide to a flask, mix and stir to obtain the desired epoxy resin pipeline paint.

[0068] The performance test method is the same as in Example 1. The tensile strength is 16.23 MPa, the elongation at break is 76%, the adhesive strength is 2675.3 MPa, the chemical resistance is that the weight loss rates are 3.05% for NaOH, 2.45% for HC1, 0.37% for NaCl, 0.34% for ethanol, and 0% for H2O; the wet heat resistance is that the weight loss rates are 3.15% for NaOH, 2.48% for HC1, 0.40% for NaCl, 0.52% for ethanol, and 0% for H2O; and the impact strength of the material is 22.3 kJ / m2. 2 The mass after friction is 1.9873 g. The thermal decomposition temperature at which the sample loses 5% of its weight is 283°C, and the thermal decomposition temperature at which the sample loses 10% of its weight is 310°C.

[0069] Example 5

[0070] The coffee acid (2 g, 11.08 mmol) was taken in a two-necked round bottom flask, tetrahydrofuran (2 mL) and N,N-dimethylformamide (0.5 mL) were added under N2atmosphere and fitted with a condenser. 2-dibutylaminoethanol (1.92 g, 11.08 mmol) was added dropwise in the flask and heated at 85°C for 4 h. After completion of the reaction, the solvent was removed as much as possible using a rotary evaporator to get the desired product (sticky liquid).

[0071] The synthesized amide (1 g, 5.54 mmol) was taken in a two-necked round bottom flask fitted with a mechanical stirrer. Epichlorohydrin (0.87 mL, 11.08 mmol) was added to it and KOH was added through a pressure balancing funnel at 70°C maintaining the drop wise rate such that the pH of the solution remains within 7.0. After completion of the addition, the resin mixture was further heated at 80°C for 2 h with continuous stirring. After cooling to room temperature, the product was transferred to a separating funnel and the two layers (aqueous and organic) were separated. The organic layer was washed several times with brine solution and distilled water to remove the impurities and unreacted reactants. Subsequently, tetrahydrofuran was added to the organic layer to dissolve the epoxy resin. Finally, tetrahydrofuran and water along with epichlorohydrin were removed using a rotary evaporator to get the desired epoxy resin as a sticky mass.

[0072] The epoxy resin sticky mass obtained was taken in 15 g and used with 50 mL of solvent (N,N-dimethylformamide) to get a suitable viscosity (500-600 mPa.s) for the next step.

[0073] A single necked flask was charged with 13.4 g of 2-methylaceto phenone, 6 g of ethylene diamine, 1.04 g of sodium hydroxide and 50 mL of N,N-dimethylformamide and heated to 70°C for 12 h. After completion of the reaction, the product was dried in an oven at 60°C for 24 h to get 2-methylaceto phenone modified ethylene diamine.

[0074] Into a flask, 10 g of diluted epoxy resin, 0.83 g of 2-methylacetylbenzophenone modified ethylenediamine, 0.07 g of talc, 0.04 g of p-hydroxybenzoate, 20 mL of N,N-dimethylformamide were added, mixed by stirring, to obtain the desired epoxy resin pipeline paint.

[0075] The performance test method is the same as in Example 1, the tensile strength is 20.08 MPa, the elongation at break is 97%, the adhesive strength is 2874.9 MPa, the chemical resistance is that the weight loss rates are 3.07% for NaOH, 2.34% for HCl, 0.36% for NaCl, 0.39% for ethanol, and 0% for H2O; the wet heat resistance is that the weight loss rates are 3.29% for NaOH, 2.56% for HCl, 0.44% for NaCl, 0.47% for ethanol, and 0% for H2O; the impact strength of the material is 24.1 kJ / m2. 2 The mass after friction is 1.9856 g; the thermal decomposition temperature at which the sample loses 5% of its weight is 281°C, and the thermal decomposition temperature at which the sample loses 10% of its weight is 304°C.

[0076] Example 6

[0077] Into a double-necked round-bottom flask, take caffeic acid (2 g, 11.08 mmol) under N2atmosphere, add tetrahydrofuran (2 mL) and N,N-dimethylformamide (0.5 mL), and equip with a condenser. Into the flask, drop in phenethylamine (1.69 g, 11.08 mmol), heat at 85°C for 4 h, after the reaction is completed, remove the solvent as much as possible by using a rotary evaporator, to obtain the desired product (thick liquid).

[0078] Into a double-necked round-bottom flask equipped with a mechanical stirrer, take (1 g, 5.54 mmol) synthesized amide, add epichlorohydrin (0.87 mL, 11.08 mmol) thereto, drop in KOH through a pressure balance funnel at 70°C, and keep the drop-in rate within 7.0 of the pH value of the solution. After the addition is completed, continue to heat the resin mixture at 80°C for 2 h, and keep stirring. After cooling to room temperature, transfer the product to a separation funnel, separate the two layers (water layer and organic layer). Wash the organic layer with a brine solution and distilled water several times, to remove impurities and unreacted reactants. Subsequently, add tetrahydrofuran to the organic layer to dissolve the epoxy resin. Finally, remove tetrahydrofuran and water together with epichlorohydrin by using a rotary evaporator, to obtain the desired epoxy resin thick substance.

[0079] Take 15 g of the obtained epoxy resin thick substance and mix with 50 ml of solvent (N,N-dimethylformamide) for use, to obtain a suitable viscosity (500-600 mPa.s) for use in the next step.

[0080] In a single neck flask, 21.2 g of benzyl 2-hydroxyphenone, 6 g of ethylenediamine, 1.04 g of sodium hydroxide and 50 mL of N,N-dimethylformamide were added and heated to 70°C for 12 h. After the reaction was completed, the product was dried in an oven at 60°C for 24 h to obtain benzyl 2-hydroxyphenone modified ethylenediamine.

[0081] In a flask, 10 g of diluted epoxy resin, 0.83 g of benzyl 2-hydroxyphenone modified ethylenediamine, 0.07 g of talc, 0.04 g of p-hydroxybenzoic acid ester, 20 mL of N,N-dimethylformamide were added, stirred and mixed to obtain the desired epoxy resin pipeline paint.

[0082] The performance test method is the same as in Example 1, the test speed is 500 mm / min, the tensile strength is 15.67 MPa, the elongation at break is 97%, the adhesive strength is 2563.7 MPa, the chemical resistance is that the weight loss rates are NaOH (3.22%), HCl (2.58%), NaCl (0.46%), ethanol (0.44%) and H2O (0%), respectively; the wet heat resistance is that the weight loss rates are NaOH (3.42%), HCl (2.69%), NaCl (0.55%), ethanol (0.47%) and H2O (0%), respectively; the impact strength of the material is 22.9 kJ / m 2 ; the mass after friction is 1.8972 g; the thermal decomposition temperature at which the sample loses 5% of its weight is 266°C, and the thermal decomposition temperature at which the sample loses 10% of its weight is 287°C.

[0083] Example 7

[0084] In a two-necked round-bottom flask, caffeic acid (2 g, 11.08 mmol) was taken and tetrahydrofuran (2 mL) and N,N-dimethylformamide (0.5 mL) were added under N2atmosphere and equipped with a condenser. In the flask, 2-aminobenzyl alcohol (1.36 g, 11.08 mmol) was added dropwise and heated at 85°C for 4 h. After the reaction was completed, the solvent was removed as much as possible using a rotary evaporator to obtain the desired product (viscous liquid).

[0085] In a two necked round bottom flask equipped with a mechanical stirrer, 1 g (5.54 mmol) of the synthesized amide was taken and to this epoxy chloropropane (0.87 mL, 11.08 mmol) was added, KOH was added through a pressure equalizing funnel at 70°C, the rate of addition was maintained such that the pH of the solution was within 7.0. After the addition was complete, the resin mixture was heated at 80°C for another 2 h with continuous stirring. After cooling to room temperature, the product was transferred to a separation funnel and the two layers (aqueous and organic) were separated. The organic layer was washed with brine solution and distilled water several times to remove the impurities and unreacted reactants. Subsequently, tetrahydrofuran was added to the organic layer to dissolve the epoxy resin. Finally, tetrahydrofuran and water along with the epoxy chloropropane were removed by a rotary evaporator to get the desired epoxy resin as a viscous mass.

[0086] The epoxy resin viscous mass obtained was taken 15 g and mixed with 50 mL of solvent (N,N-dimethylformamide) to get the desired viscosity (500-600 mPa.s) for the next step.

[0087] In a single necked flask, 19.8 g of 4-hydroxybenzophenone, 6 g of ethylene diamine, 1.04 g of sodium hydroxide and 50 mL of N,N-dimethylformamide were taken and heated to 70°C for 12 h. After completion of the reaction, the product was dried in an oven at 60°C for 24 h to get 4-hydroxybenzophenone modified ethylene diamine.

[0088] In a flask, 10 g of the diluted epoxy resin, 0.83 g of 4-hydroxybenzophenone modified ethylene diamine, 0.07 g of talc, 0.04 g of p-hydroxybenzoate, 20 mL of N,N-dimethylformamide were taken and mixed with stirring to get the desired epoxy resin pipe dope.

[0089] The performance test methods were same as in Example 1, the tensile strength was 19.23 MPa, the elongation at break was 102%, the adhesive strength was 3102.4 MPa, the chemical resistance was such that the weight loss was 3.23% in NaOH, 2.56% in HCl, 0.45% in NaCl, 0.36% in ethanol and 0% in H2O; the wet heat resistance was such that the weight loss was 3.42% in NaOH, 2.56% in HCl, 0.58% in NaCl, 0.45% in ethanol and 0% in H2O; the impact strength of the material was 20.5 kJ / m2. 2 The mass after abrasion was 1.8762 g; the thermal decomposition temperature at which the sample lost 5% of its weight was 272°C and the thermal decomposition temperature at which the sample lost 10% of its weight was 291°C.

[0090] Example 8

[0091] Take caffeic acid (2 g, 11.08 mmol) in a double necked round bottom flask, under N2atmosphere, add tetrahydrofuran (2 mL) and N, N-dimethylformamide (0.5 mL) and equip with condenser. Add 2-amino-3-methylbenzyl alcohol (1.52 g, 11.08 mmol) drop wise in the flask, heat at 85 °C for 4 h, after completion of the reaction, remove the solvent as much as possible using rotary evaporator to get the desired product (sticky liquid).

[0092] Take (1 g, 5.54 mmol) of the synthesized amide in a double necked round bottom flask equipped with a mechanical stirrer, add epichlorohydrin (0.87 mL, 11.08 mmol) to it, add KOH through a pressure balancing funnel at 70 °C, maintain the drop wise addition rate such that the pH of the solution is within 7.0. After completion of the addition, continue heating the resin mixture at 80 °C for 2 h and continue stirring. After cooling to room temperature, transfer the product to a separation funnel and separate the two layers (aqueous layer and organic layer). Wash the organic layer with brine solution and distilled water several times to remove the impurities and unreacted reactants. Subsequently, add tetrahydrofuran to the organic layer to dissolve the epoxy resin. Finally, remove the tetrahydrofuran and water along with the epichlorohydrin using a rotary evaporator to get the desired epoxy resin as a sticky mass.

[0093] Take 15 g of the epoxy resin sticky mass obtained and mix with 50 mL of solvent (N, N-dimethylformamide) to get a suitable viscosity (500-600 mPa.s) for use in the next step.

[0094] Take 21.0 g of 4,4-dimethylbenzophenone, 6 g of ethylenediamine, 1.04 g of sodium hydroxide and 50 mL of N, N-dimethylformamide in a single necked flask, heat to 70 °C and react for 12 h, after completion of the reaction, dry the product in an oven at 60 °C for 24 h to get 4,4-dimethylbenzophenone modified ethylenediamine.

[0095] Take 10 g of the diluted epoxy resin, 0.83 g of 4,4-dimethylbenzophenone modified ethylenediamine, 0.07 g of talc, 0.04 g of p-hydroxybenzoic acid ester, 20 mL of N, N-dimethylformamide in a flask, mix with stirring to get the desired epoxy resin pipe dope.

[0096] The performance test method is the same as in Example 1. The tensile strength is 20.04 MPa, the elongation at break is 87%, the adhesive strength is 3038.2 MPa, the chemical resistance is that the weight loss rates are 3.21% for NaOH, 2.23% for HC1, 0.37% for NaCl, 0.39% for ethanol, and 0% for H2O, respectively; the wet heat resistance is that the weight loss rates are 3.33% for NaOH, 2.44% for HC1, 0.48% for NaCl, 0.47% for ethanol, and 0% for H2O, respectively; the impact strength of the material is 19.6 kJ / m2. 2 The mass after friction is 1.9023 g; the thermal decomposition temperature at which the sample loses 5% of its weight is 273°C, and the thermal decomposition temperature at which the sample loses 10% of its weight is 292°C.

[0097] Example 9

[0098] The coffee acid (2 g, 11.08 mmol) was taken in a two-necked round bottom flask, tetrahydrofuran (2 mL) and N,N-dimethylformamide (0.5 mL) were added under N2atmosphere and fitted with a condenser. 4-(Methylamino)butanol (1.14 g, 11.08 mmol) was added dropwise in the flask and heated at 85°C for 4 h. After completion of the reaction, the solvent was removed as much as possible using a rotary evaporator to get the desired product (sticky liquid).

[0099] The synthesized amide (1 g, 5.54 mmol) was taken in a two-necked round bottom flask fitted with a mechanical stirrer, to which epichlorohydrin (0.87 mL, 11.08 mmol) was added. KOH was added through a pressure balancing funnel at 70°C, maintaining the drop wise addition rate such that the pH of the solution was within 7.0. After completion of the addition, the resin mixture was further heated at 80°C for 2 h with continuous stirring. After cooling to room temperature, the product was transferred to a separation funnel and the two layers (aqueous and organic) were separated. The organic layer was washed several times with brine solution and distilled water to remove the impurities and unreacted reactants. Subsequently, tetrahydrofuran was added to the organic layer to dissolve the epoxy resin. Finally, tetrahydrofuran and water along with epichlorohydrin were removed using a rotary evaporator to get the desired epoxy resin as a sticky mass.

[0100] The epoxy resin sticky mass obtained was taken in 15 g and used with 50 mL of solvent (N,N-dimethylformamide) to get a suitable viscosity (500-600 mPa.s) for the next step.

[0101] In a single necked flask, 15.4 g of menthone, 6 g of ethylenediamine, 1.04 g of sodium hydroxide and 50 mL of N,N-dimethylformamide were taken and heated to 70°C for 12 h. After completion of the reaction, the product was dried in an oven at 60°C for 24 h to get menthone modified ethylenediamine.

[0102] Into a flask, 10 g of diluted epoxy resin, 0.83 g of menthone-modified ethylenediamine, 0.07 g of talc, 0.04 g of p-hydroxybenzoate, 20 mL of N,N-dimethylformamide were added, mixed by stirring, to obtain the desired epoxy resin pipeline paint.

[0103] The performance test method is the same as in Example 1, the tensile strength is 17.45 MPa, the elongation at break is 88%, the adhesive strength is 2954.2 MPa, the chemical resistance, the weight loss rates are respectively NaOH (3.34%), HCl (2.58%), NaCl (0.48%), ethanol (0.33%), H2O (0%); the wet heat resistance, the weight loss rates are respectively NaOH (3.56%), HCl (2.63%), NaCl (0.46%), ethanol (0.54%), H2O (0%); the impact strength of the material reaches 18.9 kJ / m 2 ; the mass after friction is 1.9674 g; the thermal decomposition temperature at which the sample loses 5% of its mass is 281°C, and the thermal decomposition temperature at which the sample loses 10% of its mass is 300°C.

[0104] Example 10

[0105] Into a double-necked round-bottom flask, take caffeic acid (2 g, 11.08 mmol) under N2 atmosphere, add tetrahydrofuran (2 mL) and N,N-dimethylformamide (0.5 mL), and equip with a condenser. Into the flask, drop 3-aminocyclobutanol (0.97 g, 11.08 mmol), heat at 85°C for 4 h, after the reaction is completed, remove the solvent as much as possible with a rotary evaporator to obtain the desired product (thick liquid).

[0106] Into a double-necked round-bottom flask equipped with a mechanical stirrer, take (1 g, 5.54 mmol) synthesized amide, add epichlorohydrin (0.87 mL, 11.08 mmol) to it, drop KOH through a pressure balance funnel at 70°C, keep the drop rate within 7.0 of the solution pH value. After the addition is completed, continue to heat the resin mixture at 80°C for 2 h and continue to stir. After cooling to room temperature, transfer the product to a separation funnel, separate the two layers (water layer and organic layer). Wash the organic layer with a brine solution and distilled water several times to remove impurities and unreacted reactants. Then, add tetrahydrofuran to dissolve the epoxy resin in the organic layer. Finally, remove tetrahydrofuran and water together with epichlorohydrin through a rotary evaporator to obtain the desired epoxy resin thickener.

[0107] Take 15 g of the obtained epoxy resin thickener and mix it with 50 ml of solvent (N,N-dimethylformamide) for use to obtain a suitable viscosity (500-600 mPa.s) for the next step.

[0108] In a single neck flask, 9.8 g of cyclohexanone, 6 g of ethylenediamine, 1.04 g of sodium hydroxide and 50 mL of N,N-dimethylformamide were added and warmed to 70 °C for 12 h. After the reaction was completed, the product was dried in an oven at 60 °C for 24 h to obtain cyclohexanone modified ethylenediamine.

[0109] In a flask, 10 g of diluted epoxy resin, 0.83 g of cyclohexanone modified ethylenediamine, 0.07 g of talc, 0.04 g of p-hydroxybenzoic acid ester, 20 mL of N,N-dimethylformamide were added and mixed by stirring to obtain the desired epoxy resin pipeline paint.

[0110] The performance test method is the same as in Example 1. The tensile strength is 17.36 MPa, the elongation at break is 75%, the adhesive strength is 2653.4 MPa, the chemical resistance is 3.34% for NaOH, 2.65% for HC1, 0.39% for NaCl, 0.42% for ethanol, and 0% for H2O; the wet heat resistance is 3.47% for NaOH, 2.76% for HC1, 0.52% for NaCl, 0.53% for ethanol, and 0% for H2O; the impact strength of the material is 20.1 kJ / m2. 2 The mass after friction is 1.9892 g; the thermal decomposition temperature at which the sample loses 5% of its mass is 277 °C, and the thermal decomposition temperature at which the sample loses 10% of its mass is 290 °C.

[0111] Example 11

[0112] In a two-necked round bottom flask, caffeic acid (2 g, 11.08 mmol) was taken under N2atmosphere and tetrahydrofuran (2 mL) and N,N-dimethylformamide (0.5 mL) were added along with a condenser. To the flask, 3-amino-4-methylpentanol (1.30 g, 11.08 mmol) was added dropwise and heated at 85 °C for 4 h. After completion of the reaction, the solvent was removed as much as possible using a rotary evaporator to obtain the desired product (sticky liquid).

[0113] In a two-necked round bottom flask equipped with a mechanical stirrer, (1 g, 5.54 mmol) of the synthesized amide was taken and epichlorohydrin (0.87 mL, 11.08 mmol) was added to it. KOH was added through a pressure balancing funnel at 70 °C, maintaining the drop rate such that the pH of the solution was within 7.0. After the addition was complete, the resin mixture was heated at 80 °C for another 2 h with continuous stirring. After cooling to room temperature, the product was transferred to a separating funnel and the two layers (aqueous and organic) were separated. The organic layer was washed several times with brine solution and distilled water to remove impurities and unreacted reactants. Subsequently, tetrahydrofuran was added to the organic layer to dissolve the epoxy resin. Finally, tetrahydrofuran and water along with epichlorohydrin were removed using a rotary evaporator to obtain the desired epoxy resin as a sticky mass.

[0114] The obtained epoxy resin paste was mixed with 50 ml of solvent (N,N-dimethylformamide) to obtain a suitable viscosity (500-600 mPa.s) for the next step.

[0115] In a single-neck flask, 10.0 g of methyl isobutyl ketone, 6 g of ethylenediamine, 1.04 g of sodium hydroxide and 50 ml of N,N-dimethylformamide were added and heated to 70°C for 12 h. After the reaction was completed, the product was dried in an oven at 60°C for 24 h to obtain methyl isobutyl ketone-modified ethylenediamine.

[0116] In a flask, 10 g of the diluted epoxy resin, 0.83 g of methyl isobutyl ketone-modified ethylenediamine, 0.07 g of talc, 0.04 g of p-hydroxybenzoic acid ester, and 20 ml of N,N-dimethylformamide were added and stirred to obtain the desired epoxy resin pipeline paint.

[0117] The performance test method was the same as in Example 1, the tensile strength was 20.04 MPa, the elongation at break was 73%, the adhesive strength was 2875.4 MPa, the chemical resistance was 3.34% for NaOH, 2.76% for HCl, 0.41% for NaCl, 0.38% for ethanol, and 0% for H2O; the wet heat resistance was 3.51% for NaOH, 2.86% for HCl, 0.57% for NaCl, 0.59% for ethanol, and 0% for H2O; the impact strength of the material was 18.4 kJ / m 2 ; the mass after friction was 1.9920 g; the thermal decomposition temperature at which the sample lost 5% of its mass was 268°C, and the thermal decomposition temperature at which the sample lost 10% of its mass was 295°C.

[0118] Example 12

[0119] Caffeic acid (2 g, 11.08 mmol) was taken in a two-necked round-bottom flask, and tetrahydrofuran (2 mL) and N,N-dimethylformamide (0.5 mL) were added under N2atmosphere, and a condenser was provided. 3-Aminobenzene-1,2-diol (1.39 g, 11.08 mmol) was added dropwise in the flask, and heated at 85°C for 4 h. After the reaction was completed, the solvent was removed as much as possible using a rotary evaporator to obtain the desired product (a viscous liquid).

[0120] In a two necked round bottom flask equipped with a mechanical stirrer, 1 g (5.54 mmol) of the synthesized amide was taken and to this, epichlorohydrin (0.87 mL, 11.08 mmol) was added. KOH was added drop wise through a pressure equalizing funnel at 70°C maintaining the drop wise addition rate such that the pH of the solution was maintained at 7.0. After the addition was complete, the resin mixture was heated at 80°C for a further period of 2 h with continuous stirring. After cooling to room temperature, the product was transferred to a separation funnel and the two layers (aqueous and organic) were separated. The organic layer was washed with brine solution and distilled water several times to remove the impurities and unreacted reactants. Subsequently, tetrahydrofuran was added to the organic layer to dissolve the epoxy resin. Finally, tetrahydrofuran and water along with epichlorohydrin were removed by a rotary evaporator to obtain the desired epoxy resin as a viscous mass.

[0121] The epoxy resin viscous mass obtained was taken 15 g and mixed with 50 mL of solvent (N,N-dimethylformamide) to obtain a suitable viscosity (500-600 mPa.s) for use in the next step.

[0122] In a single necked flask, 19.6 g of 2-methylbenzophenone, 7.4 g of 1,2- propanediamine, 1.04 g of sodium hydroxide and 50 mL of N,N-dimethylformamide were taken and heated to 70°C for a period of 12 h. After completion of the reaction, the product was dried in an oven at 60°C for a period of 24 h to obtain 2-methylbenzophenone modified 1,2-propanediamine.

[0123] In a flask, 10 g of the diluted epoxy resin, 0.83 g of 2-methylbenzophenone modified 1,2-propanediamine, 0.07 g of talc, 0.04 g of p-hydroxybenzoic acid ester, 20 mL of N,N-dimethylformamide were taken and mixed with stirring to obtain the desired epoxy resin pipe dope.

[0124] The performance test methods were same as in Example 1. The tensile strength was 16.36 MPa, the elongation at break was 97%, the adhesive strength was 2879.3 MPa. The chemical resistance was as follows: the weight loss was 3.21% in NaOH, 2.23% in HCl, 0.42% in NaCl, 0.47% in ethanol and 0% in H2O; the wet heat resistance was as follows: the weight loss was 3.35% in NaOH, 2.47% in HCl, 0.52% in NaCl, 0.63% in ethanol and 0% in H2O; the impact strength of the material was 19.6 kJ / m2; the mass after abrasion was 1.9720 g; the thermal decomposition temperature at which the sample lost 5% of its weight was 274°C and the thermal decomposition temperature at which the sample lost 10% of its weight was 302°C. 2

[0125] Example 13

[0126] ​Take caffeic acid (2 g, 11.08 mmol) in a double-necked round-bottom flask, under N2atmosphere, add tetrahydrofuran (2 mL) and N,N-dimethylformamide (0.5 mL), and equip with a condenser. In the flask, drop 3-aminobenzene-1,2-diol (1.39 g, 11.08 mmol), heat at 85°C for 4 h, after completion of the reaction, remove the solvent as much as possible using a rotary evaporator, to obtain the desired product (sticky liquid).

[0127] Take (1 g, 5.54 mmol) of the synthesized amide in a double-necked round-bottom flask equipped with a mechanical stirrer, add epichlorohydrin (0.87 mL, 11.08 mmol) to it, drop KOH through a pressure balancing funnel at 70°C, keeping the drop rate within the pH of the solution 7.0. After the addition is complete, continue heating the resin mixture at 80°C for 2 h and continue stirring. After cooling to room temperature, transfer the product to a separation funnel and separate the two layers (aqueous and organic layers). Wash the organic layer several times with a saline solution and distilled water to remove impurities and unreacted reactants. Subsequently, add tetrahydrofuran to the organic layer to dissolve the epoxy resin. Finally, remove tetrahydrofuran and water along with epichlorohydrin through a rotary evaporator to obtain the desired epoxy resin paste.

[0128] Take 15 g of the obtained epoxy resin paste and use it with 50 mL of solvent (N,N-dimethylformamide) to obtain a suitable viscosity (500-600 mPa.s) for use in the next step.

[0129] In a single-necked flask, add 19.6 g of 2-methylbenzophenone, 10.2 g of 2,2-dimethyl-1,3-propanediamine, 1.04 g of sodium hydroxide, and 50 mL of N,N-dimethylformamide, and heat to 70°C for 12 h, after the reaction is complete, dry the product in an oven at 60°C for 24 h to obtain 2-methylbenzophenone-modified 2,2-dimethyl-1,3-propanediamine.

[0130] In a flask, add 10 g of the diluted epoxy resin, 0.83 g of 2-methylbenzophenone-modified 2,2-dimethyl-1,3-propanediamine, 0.07 g of talc, 0.04 g of p-hydroxybenzoic acid ester, and 20 mL of N,N-dimethylformamide, mix with stirring to obtain the desired epoxy resin pipe paint.

[0131] The performance test method is the same as in Example 1, the tensile strength is 20.23 MPa, the elongation at break is 94%, and the adhesive strength is 3121.8 MPa. The chemical resistance, the weight loss rates are NaOH (3.05%), HCl (2.19%), NaCl (0.36%), ethanol (0.38%), and H2O (0%); the wet heat resistance, the weight loss rates are NaOH (3.18%), HCl (2.47%), NaCl (0.52%), ethanol (0.47%), and H2O (0%); the impact strength of the material is 23.6 kJ / m 2 ; the mass after friction is 1.9724 g; the thermal decomposition temperature at which the sample loses 5% of its weight is 276°C, and the thermal decomposition temperature at which the sample loses 10% of its weight is 303°C.

[0132] Example 14

[0133] Take caffeic acid (2 g, 11.08 mmol) in a double-necked round-bottom flask, add tetrahydrofuran (2 mL) and N,N-dimethylformamide (0.5 mL) under N2atmosphere, and equip with a condenser. Add 3-aminobenzene-1,2-diol (1.39 g, 11.08 mmol) dropwise in the flask, heat at 85°C for 4 h, after the reaction is complete, remove the solvent as much as possible with a rotary evaporator to obtain the desired product (viscous liquid).

[0134] Take the synthesized amide (1 g, 5.54 mmol) in a double-necked round-bottom flask equipped with a mechanical stirrer, add epichlorohydrin (0.87 mL, 11.08 mmol) to it, and add KOH through a pressure balance funnel at 70°C, keeping the dropwise addition rate within 7.0 of the solution pH value. After the addition is complete, continue heating the resin mixture at 80°C for 2 h with continuous stirring. After cooling to room temperature, transfer the product to a separation funnel, separate the two layers (aqueous layer and organic layer). Wash the organic layer with a saline solution and distilled water several times to remove impurities and unreacted reactants. Subsequently, add tetrahydrofuran to dissolve the epoxy resin in the organic layer. Finally, remove tetrahydrofuran and water together with epichlorohydrin through a rotary evaporator to obtain the desired epoxy resin viscous substance.

[0135] Take 15 g of the obtained epoxy resin viscous substance and mix it with 50 ml of solvent (N,N-dimethylformamide) for use to obtain a suitable viscosity (500-600 mPa.s) for the next step.

[0136] Add 19.6 g of 2-methylbenzophenone, 11.6 g of N-butylethylenediamine, 1.04 g of sodium hydroxide, and 50 mL of N,N-dimethylformamide in a single-necked flask, and heat to 70°C for 12 h. After the reaction is complete, dry the product in an oven at 60°C for 24 h to obtain 2-methylbenzophenone-modified N-butylethylenediamine.

[0137] Into a flask, 10 g of diluted epoxy resin, 0.83 g of 2-methylbenzophenone modified N-butyl ethylenediamine, 0.07 g of talc powder, 0.04 g of p-hydroxybenzoate, 20 mL of N,N-dimethylformamide were added, mixed by stirring to obtain the desired epoxy resin pipeline paint.

[0138] The performance test method is the same as that of Example 1, the tensile strength is 19.56 MPa, the elongation at break is 101%, the adhesive strength is 3056.6 MPa, the chemical resistance is that the weight loss rates are 3.04% for NaOH, 2.47% for HCl, 0.35% for NaCl, 0.36% for ethanol, and 0% for H2O; the wet heat resistance is that the weight loss rates are 3.26% for NaOH, 2.62% for HCl, 0.43% for NaCl, 0.49% for ethanol, and 0% for H2O; the impact strength of the material reaches 18.2 kJ / m2. 2 The mass after friction is 1.9891 g; the thermal decomposition temperature at which the sample loses 5% of its weight is 283°C, and the thermal decomposition temperature at which the sample loses 10% of its weight is 297°C.

[0139] Example 15

[0140] Into a double-necked round-bottom flask, take caffeic acid (2 g, 11.08 mmol) under N2 atmosphere, add tetrahydrofuran (2 mL) and N,N-dimethylformamide (0.5 mL), and equip with a condenser. Into the flask, drop 3-aminobenzene-1,2-diol (1.39 g, 11.08 mmol), heat at 85°C for 4 h, after the reaction is completed, remove the solvent as much as possible by using a rotary evaporator to obtain the desired product (thick liquid).

[0141] Into a double-necked round-bottom flask equipped with a mechanical stirrer, take (1 g, 5.54 mmol) synthesized amide, add epichlorohydrin (0.87 mL, 11.08 mmol) thereto, drop KOH through a pressure balance funnel at 70°C, and keep the drop rate within 7.0 of the solution pH value. After the addition is completed, continue to heat the resin mixture at 80°C for 2 h and continuously stir. After cooling to room temperature, transfer the product to a separation funnel, separate the two layers (water layer and organic layer). Wash the organic layer with a saline solution and distilled water several times to remove impurities and unreacted reactants. Subsequently, add tetrahydrofuran to dissolve the epoxy resin in the organic layer. Finally, remove tetrahydrofuran and water together with epichlorohydrin by a rotary evaporator to obtain the desired epoxy resin thick substance.

[0142] Take 15 g of the obtained epoxy resin thick substance and mix with 50 ml of solvent (N,N-dimethylformamide) for use to obtain a suitable viscosity (500-600 mPa.s) for the next step.

[0143] In a single neck flask, 19.6 g of 2-methylbenzophenone, 8.6 g of 1,3-cyclobutanediamine, 1.04 g of sodium hydroxide and 50 ml of N,N-dimethylformamide were added and heated to 70 °C for 12 h. After the reaction, the product was dried in an oven at 60 °C for 24 h to obtain 2-methylbenzophenone modified 1,3-cyclobutanediamine.

[0144] In a flask, 10 g of diluted epoxy resin, 0.83 g of 2-methylbenzophenone modified 1,3-cyclobutanediamine, 0.07 g of talc, 0.04 g of p-hydroxybenzoate, 20 ml of N,N-dimethylformamide were added and mixed by stirring to obtain the desired epoxy resin pipeline paint.

[0145] The performance test method is the same as in Example 1. The tensile strength is 19.23 MPa, the elongation at break is 93%, the adhesive strength is 2874.2 MPa. The chemical resistance is that the weight loss rates are NaOH (3.17%), HCl (2.23%), NaCl (0.37%), ethanol (0.39%), and H2O (0%); the wet heat resistance is that the weight loss rates are NaOH (3.37%), HCl (2.52%), NaCl (0.43%), ethanol (0.48%), and H2O (0%); the impact strength of the material is 22.8 kJ / m 2 ; the mass after friction is 1.8862 g; the thermal decomposition temperature at which the sample loses 5% of its weight is 265 °C, and the thermal decomposition temperature at which the sample loses 10% of its weight is 288 °C.

[0146] Comparative Example 1

[0147] The epoxy resin paste was prepared as in Example 1.

[0148] The obtained epoxy resin paste was mixed with 50 ml of solvent (N,N-dimethylformamide) to obtain a suitable viscosity (500-600 mPa.s) for the next step.

[0149] In a flask, 10 g of diluted epoxy resin, 0.83 g of 2-methylbenzophenone modified 1,3-cyclobutanediamine, 0.07 g of talc, 0.04 g of p-hydroxybenzoate, 20 ml of N,N-dimethylformamide were added and mixed by stirring to obtain the desired epoxy resin pipeline paint.

[0150] The performance test method is the same as in Example 1. The tensile strength is 8.62 MPa, the elongation at break is 57%, the adhesive strength is 1132.6 MPa. The chemical resistance is that the weight loss rates are NaOH (14.83%), HCl (12.62%), NaCl (13.62%), ethanol (15.84%), and H2O (0%), respectively. The wet heat resistance is that the weight loss rates are NaOH (15.12%), HCl (14.43%), NaCl (16.38%), ethanol (18.38%), and H2O (0%), respectively. The impact strength of the material is 9.3 kJ / m 2 ; the mass after friction is 1.5391 g; the thermal decomposition temperature at which the sample weight loss is 5% is 196°C, and the thermal decomposition temperature at which the sample weight loss is 10% is 225°C.

[0151] Comparative Example 2

[0152] The epoxy resin paste is prepared in the same manner as in Example 1.

[0153] The obtained epoxy resin paste is mixed with 50 ml of solvent (N, N-dimethylformamide) to obtain a suitable viscosity (500-600 mPa.s) for the next step.

[0154] In a single-necked flask, 7.2 g of ketone, 6 g of ethylenediamine, 1.04 g of sodium hydroxide, and 50 ml of N, N-dimethylformamide are added, and the temperature is raised to 70°C, and the reaction is carried out for 12 h. After the reaction is completed, the product is dried in an oven at 60°C for 24 h to obtain ketone-modified ethylenediamine.

[0155] In a flask, 10 g of the diluted epoxy resin, 0.83 g of ketone-modified ethylenediamine, 0.07 g of talc, 0.04 g of p-hydroxybenzoate, and 20 ml of N, N-dimethylformamide are added, and mixed by stirring to obtain the desired epoxy resin pipeline paint.

[0156] The performance test method is the same as in Example 1. The tensile strength is 10.65 MPa, the elongation at break is 58%, the adhesive strength is 1483.6 MPa. The chemical resistance is that the weight loss rates are NaOH (10.82%), HCl (11.43%), NaCl (7.32%), ethanol (8.74%), and H2O (0%), respectively. The wet heat resistance is that the weight loss rates are NaOH (13.32%), HCl (8.29%), NaCl (15.27%), ethanol (16.23%), and H2O (0%), respectively. The impact strength of the material is 12.5 kJ / m 2 ; the mass after friction is 1.6290 g; the thermal decomposition temperature at which the sample weight loss is 5% is 203°C, and the thermal decomposition temperature at which the sample weight loss is 10% is 237°C.

[0157] Comparative Example 3

[0158] Commercially available epoxy resin paste (Epoxy 301) was mixed with 50 ml of solvent (N, N-dimethylformamide) to obtain a suitable viscosity for the next step.

[0159] In a single-necked flask, 19.6 g of 2-methylbenzophenone, 6 g of ethylenediamine, 1.04 g of sodium hydroxide and 50 ml of N, N-dimethylformamide were added and heated to 70°C for 12 h. After the reaction, the product was dried in an oven at 60°C for 24 h to obtain 2-methylbenzophenone-modified ethylenediamine.

[0160] In a flask, 10 g of diluted epoxy resin, 0.83 g of 2-methylbenzophenone-modified ethylenediamine, 0.07 g of talc, 0.04 g of p-hydroxybenzoic acid ester and 20 ml of N, N-dimethylformamide were mixed and stirred to obtain the desired epoxy resin pipeline paint.

[0161] The performance test method was the same as in Example 1. The tensile strength was 7.38 MPa, the elongation at break was 43%, the adhesive strength was 882.3 MPa. The chemical resistance was as follows: the weight loss rates were 17.45% for NaOH, 16.76% for HCl, 14.58% for NaCl, 16.25% for ethanol and 0% for H2O; the wet heat resistance was as follows: the weight loss rates were 18.27% for NaOH, 19.22% for HCl, 17.08% for NaCl, 20.14% for ethanol and 0% for H2O; the impact strength of the material was 8.6 kJ / m2. 2 The mass after friction was 1.5032 g; the thermal decomposition temperature at which the sample weight loss was 5% was 178°C and the thermal decomposition temperature at which the sample weight loss was 10% was 197°C.

Claims

1. A process for the preparation of an epoxy pipeline paint characterized by: The preparation method comprises the following steps: (1) synthesis of caffeic acid amide The caffeic acid is taken into a double-necked round-bottom flask equipped with a condenser, and tetrahydrofuran and N,N-dimethylformamide are added under N2 atmosphere. Then, an alcohol amine is added dropwise into the flask, and heating is performed at 85℃ for 4h. After the reaction is completed, the solvent is removed by rotary evaporation to obtain a viscous liquid caffeic acid amide; The alcohol amine is one or a mixture of several of diethanolamine, triethanolamine, methyl alcohol amine, ethyl alcohol amine, 2-dibutylaminoethanol, phenethyl alcohol amine, 2-aminobenzene methanol, 2-amino-3-methylbenzene methanol, 4-(methylamino)butanol, 3-aminocyclobutanol, 3-amino-4-methylpentanol, 3-aminobenzene-1,2-diol, 1-amino-3-methoxypropan-2-ol, 2-amino-4-methylpentanol, 2-(dimethylamino)propane-1,3-diol; (2) preparation of epoxy resin paste The caffeic acid amide synthesized in step (1) is added into a double-necked round-bottom flask equipped with a mechanical stirrer, and then epichlorohydrin and KOH are added dropwise into the flask under stirring at 70℃. The mixture is continuously heated at 80℃ for 2h. After cooling to room temperature, the product is transferred into a separation funnel for layer separation, and the organic layer is washed with a brine solution and distilled water. Then, the epoxy resin is dissolved in the organic layer by adding tetrahydrofuran. The tetrahydrofuran, water and epichlorohydrin are removed by rotary evaporation to obtain the epoxy resin paste. (3) preparation of epoxy pipeline paint The epoxy resin paste is mixed with N,N-dimethylformamide to obtain a diluted epoxy resin. When used, the diluted epoxy resin is added with an organic ketone modified organic amine curing agent, a pigment filler, a polymer additive and a solvent to obtain the epoxy pipeline paint. The method for modifying the organic amine with the organic ketone comprises the following steps: adding the organic ketone, the organic amine, sodium hydroxide and N,N-dimethylformamide into a single-necked flask, and heating to 70℃. The reaction is performed for 12h. After the reaction is completed, the product is dried in an oven at 60℃ for 24h. The organic ketone is one or a mixture of several of 2-methylbenzophenone, benzophenone, 4-phenylbenzophenone, 1-hydroxycyclohexyl phenone, 2-methylacetylbenzophenone, benzyl 2-hydroxybenzophenone, 4-hydroxybenzophenone, 4,4'-dimethylbenzophenone, menthone, cyclohexanone, methyl isobutyl ketone. The organic amine is one or a mixture of several of ethylenediamine, 1,2-propylenediamine, 2,2-dimethyl-1,3-propylenediamine, N-butylethylenediamine, 1,3-cyclobutane diamine, 2,5-dimethyl-1,4-phenylenediamine, 1,8-octylenediamine, N-methyl-1,2-phenylenediamine, p-phenylenediamine, N,N-diethyl-p-phenylenediamine, o-xylylenediamine, 4,5-dimethyl-1,2-phenylenediamine. The polymer additive is p-hydroxybenzoic acid ester.

2. The method of making an epoxy pipe paint according to claim 1, characterized in that: In step (1), the molar ratio of the caffeic acid to the alcohol amine is 1:

1.

3. The method of making an epoxy pipe coating paint according to claim 1, characterized in that: In step (2), the molar ratio of the caffeic acid amide to the epichlorohydrin is 1:

2. The pH value of the solution is kept within 7.0 by adding KOH dropwise.

4. The method of making an epoxy pipe coating paint according to claim 1, characterized in that: In step (3), the molar ratio of the organic ketone to the organic amine is 1:1, and the amount of sodium hydroxide is 5%-8% of the mass of the organic ketone.

5. The method of making an epoxy pipe coating paint according to claim 1, characterized in that: The amount of the organic ketone modified organic amine added in step (3) is 8%-15% of the total mass of the diluted epoxy resin; the solvent is N,N-dimethylformamide.

6. The method of making an epoxy pipe coating paint according to claim 1, characterized in that: The color filler in step (3) is talc, and the amount of talc is 6%-10% of the mass of the organic ketone modified organic amine curing agent; the amount of the high polymer additive is 3%-8% of the mass of the organic ketone modified organic amine curing agent.

7. An epoxy pipeline paint prepared by the method according to any one of claims 1-6.

8. Use of an epoxy pipe paint prepared according to the method of any one of claims 1 to 6, characterized in that The paint is used for coating cast iron pipes and cast iron fittings for building drainage.

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