A kind of high temperature and high pressure resistant corrosion resistant powder coating and preparation method thereof

Abstract

The present application relates to the technical field of anti-corrosion powder coatings, and specifically discloses a high temperature and high pressure corrosion resistant powder coating and a preparation method thereof. The raw materials used for a high temperature and high pressure corrosion resistant powder coating include the following components in parts by weight: 190-225 parts of epoxy resin main material; 50-60 parts of curing agent; 30-35 parts of reinforcing agent; 3-5 parts of other additives; 80-100 parts of filler; 3-5 parts of pigment; the main material of epoxy resin includes glycidylamine type epoxy resin and glycidyl ether type epoxy resin; its preparation method is: all the raw materials are mixed evenly, melt-extruded, cooled, crushed, and sieved to obtain the product. The product of the present application can be used for pipeline coating, which has the advantages of effectively protecting the pipeline and increasing the service life of the pipeline; in addition, the preparation method of the present application has the advantages of simple steps and easy availability of raw materials.

Description

Technical Field

[0001] The present application relates to the technical field of anti-corrosion powder coatings, and more specifically, to a high temperature and high pressure resistant anti-corrosion powder coating and a preparation method thereof. Background Art

[0002] Powder coating is a solid powdered substance that does not contain water and organic solvents. It is sprayed onto the object to be coated. After baking, the powder coating melts and flows level, and then solidifies after chemical cross-linking to form a flat and hard coating film.

[0003] Among many powder coatings, epoxy resin powder coatings are usually used as raw materials for inner wall coatings of pipelines for hot water, natural gas, crude oil and refined oil because of their certain corrosion resistance, heat resistance and metal adhesion. The coating formed by epoxy resin powder coatings can play a significant role in protecting pipelines.

[0004] However, the working position of the oil pipes and casings used in the various pipelines of China National Petroleum Corporation can reach a depth of more than six kilometers, the working temperature is higher than 130°C, and the pipeline contains a variety of corrosive substances. The pipeline coating that has been operating for a long time under such high temperature and high pressure conditions is prone to high temperature deformation and aging, and the coating cracks and breaks due to insufficient mechanical strength and cross-linking. These problems will cause the pipeline to be damaged by corrosive substances and affect the normal use of the pipeline. Therefore, in order to meet the actual use requirements of protecting pipelines and increasing the service life of pipelines, powder coatings must have good corrosion resistance as well as excellent heat resistance and high pressure resistance. The existing powder coatings still have room for further optimization in improving corrosion resistance and high temperature and high pressure resistance. Summary of the invention

[0005] In order to solve the above technical problems, the present application provides a high temperature and high pressure resistant corrosion resistant powder coating and a preparation method thereof.

[0006] In the first aspect, the present application provides a high temperature and high pressure resistant corrosion resistant powder coating, which adopts the following technical scheme: a high temperature and high pressure resistant corrosion resistant powder coating, the raw materials used include the following components in parts by weight: 190-225 parts of epoxy resin main material; 50-60 parts of curing agent; 30-35 parts of reinforcing agent; 3-5 parts of other auxiliary agents; 80-100 parts of filler; 3-5 parts of pigment; the epoxy resin main material includes glycidyl amine type epoxy resin and glycidyl ether type epoxy resin.

[0007] Preferably, the weight ratio of the glycidylamine epoxy resin to the glycidylether epoxy resin is (5-8):(15-17).

[0008] By adopting the above technical scheme, the present application adopts a mixture of glycidylamine epoxy resin and glycidyl ether epoxy resin in a certain weight ratio as the epoxy resin main material of the corrosion-resistant powder coating, wherein the glycidylamine epoxy resin has good heat resistance, mechanical strength and cross-linking degree, and the glycidyl ether epoxy resin has good corrosion resistance, and the two play a synergistic role to a large extent, significantly improving the high temperature and high pressure resistance and corrosion resistance of the epoxy resin main material; at the same time, the present application also adds components such as curing agent, reinforcing agent, other auxiliary agents and fillers to mix and match with the epoxy resin main material, giving full play to the synergistic effect between each other, significantly optimizing the performance of the corrosion-resistant powder coating itself, so that it has high temperature and high pressure resistance under the condition of high corrosion resistance.

[0009] Preferably, the glycidyl ether epoxy resin comprises bisphenol A epoxy resin and polyether hyperbranched epoxy resin in a weight ratio of (505-508):(55.8-56.7).

[0010] By adopting the above technical scheme, the polyether hyperbranched epoxy resin as the raw material of the powder coating can reduce the viscosity of the powder coating itself, and compared with other types of hyperbranched epoxy resins, the polyether hyperbranched epoxy resin has higher chemical stability, and can also improve the cross-linking density of the coating to a certain extent. The present application adopts a bisphenol A epoxy resin with high corrosion resistance and a polyether hyperbranched epoxy resin mixed and used in a certain proportion range as a glycidyl ether epoxy resin. The two play a synergistic role, while optimizing the viscosity, cross-linking degree and chemical stability of the powder coating, ensuring that the powder coating has good corrosion resistance.

[0011] Preferably, the polyether type hyperbranched epoxy resin is prepared by the following steps:

[0012] S1. Add a catalytic amount of a catalyst to a mixture of 3,5-dihydroxybenzoic acid and octyl glycidyl ether in a weight ratio of (154-160):(168-180), mix well and dissolve in a solvent, continue to introduce nitrogen and react at 85-95° C. for 4.5-5.5 h, then wash and dry to obtain a primary product;

[0013] S2. Add trimethylolpropane triglycidyl ether and a catalytic amount of a catalyst to the primary product, mix well and dissolve in a solvent, wherein the amount of trimethylolpropane triglycidyl ether is 585-589wt% of the amount of 3,5-dihydroxybenzoic acid, continuously introduce nitrogen and react at 85-95°C for 4.5-5.5h, wash and dry to obtain a polyether type hyperbranched epoxy resin.

[0014] By adopting the above technical scheme, the present application uses 3,5-dihydroxybenzoic acid and octyl glycidyl ether as raw materials to prepare a high-purity primary product, and then adds trimethylolpropane triglycidyl ether to the primary product and conducts a polymerization reaction to obtain a polyether-type hyperbranched epoxy resin; compared with other types of hyperbranched epoxy resins, polyether-type epoxy resins have better chemical stability and can also improve the cross-linking density of the coating; the polyether-type hyperbranched epoxy resin prepared by octyl glycidyl ether in the present application has a hydrophobic flexible long chain (octyl benzoate side group), which can reduce its own viscosity, and at the same time make the polyether-type hyperbranched epoxy resin have a denser internal structure, reducing the possibility of corrosive substances penetrating into the coating and corroding the pipeline.

[0015] Preferably, the bisphenol A epoxy resin is modified by the following steps:

[0016] Bisphenol A epoxy resin and diphenylsilane diol in a weight ratio of (100-120):(30-33) are uniformly mixed, and then a stannous octoate catalyst is added, and the mixture is reacted at a temperature of 110-130° C. for 2.0-2.5 hours to obtain a modified bisphenol A epoxy resin.

[0017] By adopting the above-mentioned technical scheme, the present application adopts bisphenol A epoxy resin modified by diphenylsilanediol under the catalysis of stannous octoate catalyst, which can improve the heat resistance of powder coating without affecting the viscosity and crosslinking density of powder coating, and the stannous octoate catalyst has a very high catalytic activity compared with other catalysts, which significantly improves the conversion rate of the modification reaction of bisphenol A epoxy resin, and obtains modified bisphenol A epoxy resin with high product purity.

[0018] Preferably, the amount of the stannous octoate catalyst added is 0.5-1.5 wt % of the amount of the bisphenol A epoxy resin used.

[0019] Preferably, the amount of the stannous octoate catalyst added is 1.0 wt % of the amount of the bisphenol A epoxy resin used.

[0020] As the amount of stannous octoate catalyst increases, the heat resistance of the modified bisphenol A epoxy resin will decrease accordingly. However, if the amount of stannous octoate catalyst is too small, the reaction degree will be incomplete and the product purity will be too low. Therefore, by adopting the above-mentioned technical scheme, the application further limits the addition amount of the stannous octoate catalyst to 0.5-1.5wt% of the amount of the bisphenol A epoxy resin, so that it can effectively catalyze the forward reaction without affecting the heat resistance of the bisphenol A epoxy resin; and experimental data confirm that when the amount of stannous octoate catalyst added is 1.0wt% of the amount of the bisphenol A epoxy resin, the catalytic effect is best, and the influence on the heat resistance of the bisphenol A epoxy resin is negligible.

[0021] Preferably, the curing agent is 1,3-cyclohexanedimethylamine and 4,4'-diaminodicyclohexylmethane in a weight ratio of (4-5):(2.5-2.8).

[0022] By adopting the above technical scheme, the present application adopts 1,3-cyclohexanedimethylamine with good mechanical strength and heat resistance and 4,4'-diaminodicyclohexylmethane with low viscosity as a curing agent, and 1,3-cyclohexanedimethylamine and 4,4'-diaminodicyclohexylmethane have good compatibility and significant synergistic effect, which can significantly optimize the viscosity and internal cross-linking degree of the powder coating while ensuring that the powder coating has good heat resistance and mechanical strength.

[0023] Preferably, the other additives include one or more of a stabilizer, a defoamer and a leveling agent.

[0024] By adopting the above technical solutions, the stabilizer can improve the thermal stability of the powder coating, the defoamer can improve the gloss and smoothness of the coating surface, the leveling agent can improve the leveling speed of the powder coating, and the other additives outlined above can improve the thermal stability of the powder coating, optimize the coating flatness, and reduce the possibility of coating cracking.

[0025] In the second aspect, the present application also provides a method for preparing a high temperature and high pressure resistant corrosion resistant powder coating, comprising the following steps: mixing all raw materials evenly and melt-extruding at a temperature of 140-155°C, cooling, crushing, and screening to obtain a high temperature and high pressure resistant corrosion resistant powder coating.

[0026] By adopting the above technical scheme, all raw materials are mixed evenly, melt granulated, crushed and sieved to obtain high temperature resistant, bending resistant and corrosion resistant powder coating. The preparation method is simple and fast, the raw materials are easily available, and the cost is low, providing a simple and efficient powder coating preparation method.

[0027] In summary, this application has the following beneficial technical effects:

[0028] 1. This application uses glycidylamine epoxy resin and glycidyl ether epoxy resin as the main materials of powder coatings, and mixes with a variety of substances for use, giving full play to the synergistic effect between the components, so that the anti-corrosion powder coating has both high temperature and high pressure resistance and corrosion resistance;

[0029] 2. The powder coating preparation method provided in this application has simple steps and readily available raw materials. The prepared powder coating has good high temperature and high pressure resistance and corrosion resistance, thereby effectively protecting the pipeline and increasing the service life of the pipeline. DETAILED DESCRIPTION

[0030] Material Source

[0031] Unless otherwise specified, the raw materials used in this application are all commercially available products, specifically: 3,5-dihydroxybenzoic acid was purchased from Shandong Changyao New Materials Co., Ltd., model CY-Y3Y;

[0032] Octyl glycidyl ether was purchased from Wuhan Kemik Biopharmaceutical Technology Co., Ltd.;

[0033] Tetrabutylammonium bromide was purchased from Shandong Hongyunchang Chemical Technology Co., Ltd.;

[0034] N,N-dimethylformamide was purchased from Shandong Chuangying Chemical Co., Ltd.;

[0035] Butyl glycidyl ether was purchased from Jinan Xinquan Chemical Technology Co., Ltd.;

[0036] Decyl glycidyl ether was purchased from Wuhan Kemik Biopharmaceutical Technology Co., Ltd.;

[0037] Polyester hyperbranched epoxy resin was purchased from Jining Huakai Resin Co., Ltd., model HC-451F;

[0038] Bisphenol A epoxy resin was purchased from Langfang Rongwei Anticorrosion Materials Co., Ltd., model 6101 / E-44;

[0039] Stannous octoate catalyst was purchased from Shandong Guohua Chemical Co., Ltd.;

[0040] Diphenylsilanediol was purchased from Wuhan Lanabai Pharmaceutical Chemical Co., Ltd.;

[0041] Manganese dioxide was purchased from Hunan Daji Manganese Industry Co., Ltd.;

[0042] Tetrabutyl orthotitanate was purchased from Jinan Jinbang Environmental Protection Technology Co., Ltd.;

[0043] Polydimethylsiloxane was purchased from Jinan Hongtai Chemical Co., Ltd., model number 02301000237;

[0044] Tetraglycidyl diaminodiphenylmethane was purchased from Wenzhou Shoucheng Chemical Technology Co., Ltd., model SC-01; zinc oxide was purchased from Henan Mingzhixin Chemical Products Co., Ltd.;

[0045] Green silicon carbide powder was purchased from Zhengzhou Haixu Abrasive Co., Ltd., with a mesh size of 3000 and a Mohs hardness of 9.4; Ultramarine was purchased from Jiangsu Rayne Environmental Protection Technology Co., Ltd.;

[0046] Titanium dioxide was purchased from Hebei Weicai Pigment Co., Ltd.;

[0047] 1,3-Cyclohexyldimethylamine was purchased from Nantong Runfeng Petrochemical Co., Ltd.;

[0048] 4,4'-Diaminodicyclohexylmethane was purchased from Jiangsu Runfeng Synthetic Technology Co., Ltd. with a molecular weight of 210.36;

[0049] Magnesium fluorosilicate was purchased from Henan Mingzhixin Chemical Products Co., Ltd.;

[0050] The water-based isocyanate curing agent was purchased from Wuhan Shiquanxing New Materials Technology Co., Ltd., model S-208; the methyltin mercaptan stabilizer was purchased from Jinan Chaoyixing Chemical Co., Ltd., specification 2536697076;

[0051] Polyamide wax was purchased from Shanghai Tongshi Technology Co., Ltd., model number PA-103;

[0052] The silicone leveling agent was purchased from Laiyang Shengbang Silicone Technology Co., Ltd., model SI-X101.

[0053] Preparation Example 1

[0054] The preparation method of polyether type hyperbranched epoxy resin comprises the following steps:

[0055] S1. Add 1.61 kg of tetrabutylammonium bromide to a mixture of 15.4 kg of 3,5-dihydroxybenzoic acid and 18.0 kg of octyl glycidyl ether, mix well and dissolve in N,N-dimethylformamide, continue to introduce nitrogen and react at 85° C. for 5.5 h, then wash and dry to obtain a primary product;

[0056] S2. Add 91.6 kg of trimethylolpropane triglycidyl ether and 12.9 kg of tetrabutylammonium bromide to all the primary products, mix them evenly, dissolve them in N,N-dimethylformamide, continue to introduce nitrogen and react at 95° C. for 4.5 hours, wash and dry to obtain a polyether hyperbranched epoxy resin.

[0057] Preparation Example 2

[0058] The preparation method of polyether type hyperbranched epoxy resin comprises the following steps:

[0059] S1. Add 1.69 kg of tetrabutylammonium bromide to a mixture of 16.0 kg of 3,5-dihydroxybenzoic acid and 16.8 kg of octyl glycidyl ether, mix well and dissolve in N,N-dimethylformamide, continue to introduce nitrogen and react at 85° C. for 5.5 h, then wash and dry to obtain a primary product;

[0060] S2. Add 94.2 kg of trimethylolpropane triglycidyl ether and 13.5 kg of tetrabutylammonium bromide to all the primary products and mix them evenly, dissolve them in N,N-dimethylformamide, continue to introduce nitrogen and react at 95° C. for 4.5 h, wash and dry to obtain a polyether hyperbranched epoxy resin.

[0061] Preparation Example 3

[0062] The preparation method of the polyether type hyperbranched epoxy resin is different from that of Preparation Example 1 in that octyl glycidyl ether is replaced by butyl glycidyl ether, and the rest is the same as that of Preparation Example 1.

[0063] Preparation Example 4

[0064] The preparation method of the polyether type hyperbranched epoxy resin is different from that of Preparation Example 1 in that octyl glycidyl ether is replaced by decyl glycidyl ether, and the rest is the same as that of Preparation Example 1.

[0065] Preparation Example 5

[0066] The modification process of bisphenol A epoxy resin comprises the following steps:

[0067] 100 kg of bisphenol A epoxy resin and 33 kg of diphenylsilanediol were uniformly mixed, and then 2 kg of stannous octoate catalyst was added, and the mixture was reacted at a temperature of 110° C. for 2.5 hours to obtain a modified bisphenol A epoxy resin.

[0068] Preparation Example 6

[0069] The modification process of bisphenol A epoxy resin comprises the following steps:

[0070] 120 kg of bisphenol A epoxy resin and 30 kg of diphenylsilanediol were uniformly mixed, and 0.36 kg of stannous octoate catalyst was added, and the mixture was reacted at a temperature of 130° C. for 2.0 h to obtain a modified bisphenol A epoxy resin.

[0071] Preparation Example 7

[0072] The modification treatment of bisphenol A epoxy resin is different from that of Preparation Example 5 in that the stannous octoate catalyst is replaced by manganese dioxide, and the rest is the same as Preparation Example 5.

[0073] Preparation Example 8

[0074] The modification treatment of bisphenol A epoxy resin is different from that of Preparation Example 5 in that the stannous octoate catalyst is replaced by tetrabutyl orthotitanate, and the rest is the same as Preparation Example 5.

[0075] Preparation Example 9

[0076] The modification treatment of bisphenol A epoxy resin is different from that of Preparation Example 5 in that the amount of stannous octoate catalyst added is 1.5 kg, and the rest is the same as Preparation Example 5.

[0077] Preparation Example 10

[0078] The modification treatment of bisphenol A epoxy resin is different from that of Preparation Example 5 in that the amount of stannous octoate catalyst added is 0.5 kg, and the rest is the same as Preparation Example 5.

[0079] Preparation Example 11

[0080] The modification treatment of bisphenol A epoxy resin is different from that of Preparation Example 5 in that the amount of stannous octoate catalyst added is 1.0 kg, and the rest is the same as Preparation Example 5.

[0081] Preparation Example 12

[0082] The modification treatment of bisphenol A epoxy resin is different from that of Preparation Example 5 in that diphenylsilanediol is replaced by polydimethylsiloxane, and the rest is the same as Preparation Example 5.

[0083] Example 1

[0084] A method for preparing a high temperature and high pressure resistant corrosion resistant powder coating comprises the following steps:

[0085] 146.8kg of bisphenol A epoxy resin, 43.2kg of tetraglycidyldiaminodiphenylmethane, 60kg of 1,3-cyclohexanedimethylamine, 30kg of zinc oxide, 80kg of green silicon carbide powder, 5kg of other additives (1.5kg of methyl tin mercaptan stabilizer, 2.0kg of silicone leveling agent, 1.5kg of polyamide wax) and 5kg of pigment (2kg of titanium dioxide, 3kg of ultramarine) were all mixed and uniformly melted and extruded at a temperature of 140°C, cooled, crushed, and passed through a 540-mesh sieve to obtain a high temperature and pressure resistant corrosion-resistant powder coating.

[0086] Example 2

[0087] A method for preparing a high temperature and high pressure resistant corrosion resistant powder coating comprises the following steps:

[0088] 78.3 kg of tetraglycidyldiaminodiphenylmethane, 146.7 kg of bisphenol A epoxy resin, 50 kg of 4,4'-diaminodicyclohexylmethane, 35 kg of zinc oxide, 3 kg of other additives (0.5 kg of methyltin mercaptan stabilizer, 2.5 kg of silicone leveling agent), 100 kg of green silicon carbide micropowder and 3 kg of pigment (1.4 kg of titanium dioxide, 1.6 kg of ultramarine) were all mixed and evenly melted and extruded at a temperature of 155 ° C, cooled, crushed, and passed through a 540 mesh sieve to obtain a high temperature and pressure resistant corrosion-resistant powder coating.

[0089] Example 3

[0090] A method for preparing a high temperature, high pressure and corrosion resistant powder coating, which is different from Example 1 in that: tetraglycidyl diaminodiphenylmethane is 38 kg, bisphenol A type epoxy resin is 152 kg, and the rest is the same as Example 1.

[0091] Example 4

[0092] A method for preparing a high temperature, high pressure and corrosion resistant powder coating, which is different from Example 1 in that: tetraglycidyl diaminodiphenylmethane is 76 kg, bisphenol A type epoxy resin is 114 kg, and the rest is the same as Example 1.

[0093] Embodiment 5-8

[0094] A method for preparing a high temperature, high pressure and corrosion resistant powder coating, which is different from Example 1 in that: 146.8 kg of bisphenol A epoxy resin is replaced with bisphenol A epoxy resin and the polyether hyperbranched epoxy resin prepared in Preparation Example 1, and the rest is the same as Example 1, and the specific amounts are shown in Table 1:

[0095] Table 1

[0096] Group Bisphenol A epoxy resin / kg Polyether type hyperbranched epoxy resin / kg Example 5 132.0 14.8 Example 6 132.3 14.5 Example 7 121.5 25.3 Example 8 133.9 12.9

[0097] Example 9

[0098] A method for preparing a high temperature, high pressure and corrosion resistant powder coating, which is different from Example 1 in that 146.8 kg of bisphenol A epoxy resin is replaced by 132 kg of bisphenol A epoxy resin and 14.8 kg of polyether hyperbranched epoxy resin obtained in Preparation Example 2, and the rest is the same as Example 1.

[0099] Example 10

[0100] A method for preparing a high temperature, high pressure and corrosion resistant powder coating, which is different from Example 1 in that 146.8 kg of bisphenol A epoxy resin is replaced by 132 kg of bisphenol A epoxy resin and 14.8 kg of polyether hyperbranched epoxy resin obtained in Preparation Example 3, and the rest is the same as Example 1.

[0101] Embodiment 11

[0102] A method for preparing a high temperature, high pressure and corrosion resistant powder coating, which is different from Example 1 in that 146.8 kg of bisphenol A epoxy resin is replaced by 132 kg of bisphenol A epoxy resin and 14.8 kg of polyether hyperbranched epoxy resin obtained in Preparation Example 4, and the rest is the same as Example 1.

[0103] Example 12

[0104] A method for preparing a high temperature, high pressure and corrosion resistant powder coating, which is different from Example 1 in that: 146.8 kg of bisphenol A epoxy resin is completely replaced by the polyether hyperbranched epoxy resin prepared in Preparation Example 1, and the rest is the same as Example 1.

[0105] Embodiment 13

[0106] A method for preparing a high temperature, high pressure and corrosion resistant powder coating, which is different from Example 1 in that 146.8 kg of bisphenol A epoxy resin is replaced by 132 kg of bisphenol A epoxy resin and 14.8 kg of polyester hyperbranched epoxy resin, and the rest is the same as Example 1.

[0107] Examples 14-21

[0108] A method for preparing a high temperature, high pressure and corrosion resistant powder coating, which is different from Example 5 in that the bisphenol A epoxy resin is replaced by the modified bisphenol A epoxy resin obtained in Preparation Examples 5-12 respectively, and the rest is the same as Example 5.

[0109] Embodiment 22

[0110] A method for preparing a high temperature, high pressure and corrosion resistant powder coating, which is different from Example 1 in that 60 kg of 1,3-cyclohexanedimethylamine is replaced by 35.3 kg of 1,3-cyclohexanedimethylamine and 24.7 kg of 4,4'-diaminodicyclohexylmethane, and the rest is the same as Example 1.

[0111] Embodiment 23

[0112] A method for preparing a high temperature, high pressure and corrosion resistant powder coating, which is different from Example 1 in that 60 kg of 1,3-cyclohexanedimethylamine is replaced by 40.0 kg of 1,3-cyclohexanedimethylamine and 20.0 kg of 4,4'-diaminodicyclohexylmethane, and the rest is the same as Example 1.

[0113] Embodiment 24

[0114] A method for preparing a high temperature, high pressure and corrosion resistant powder coating, which is different from Example 1 in that 60 kg of 1,3-cyclohexanedimethylamine is replaced by 30.0 kg of 1,3-cyclohexanedimethylamine and 30.0 kg of 4,4'-diaminodicyclohexylmethane, and the rest is the same as Example 1.

[0115] Embodiment 25

[0116] A method for preparing a high temperature, high pressure and corrosion resistant powder coating, which is different from Example 1 in that 60 kg of 1,3-cyclohexanedimethylamine is replaced by 45.0 kg of 1,3-cyclohexanedimethylamine and 15.0 kg of 4,4'-diaminodicyclohexylmethane, and the rest is the same as Example 1.

[0117] Embodiment 26

[0118] A method for preparing a high temperature, high pressure and corrosion resistant powder coating, which is different from Example 1 in that 60 kg of 1,3-cyclohexanedimethylamine is replaced by 35.3 kg of magnesium fluorosilicate and 24.7 kg of 4,4'-diaminodicyclohexylmethane, and the rest is the same as Example 1.

[0119] Embodiment 27

[0120] A method for preparing a high temperature, high pressure and corrosion resistant powder coating, which is different from Example 1 in that 60 kg of 1,3-cyclohexanedimethylamine is replaced by 35.3 kg of 1,3-cyclohexanedimethylamine and 24.7 kg of water-based isocyanate curing agent, and the rest is the same as Example 1.

[0121] Comparative Example 1

[0122] The difference from Example 1 is that 43.2 kg of tetraglycidyl diaminodiphenylmethane and 146.8 kg of bisphenol A epoxy resin are replaced with 190 kg of bisphenol A epoxy resin, and the rest is the same as Example 1.

[0123] Comparative Example 2

[0124] The difference from Example 1 is that 43.2 kg of tetraglycidyl diaminodiphenylmethane and 146.8 kg of bisphenol A epoxy resin are replaced by 190 kg of tetraglycidyl diaminodiphenylmethane, and the rest is the same as Example 1.

[0125] Performance Testing

[0126] The anti-corrosion powders prepared in Examples 1-27 and Comparative Examples 1-2 were respectively sprayed on oil pipeline samples with a size of 200 mm×25 mm×6 mm. After forming a coating on the pipeline surface, several coated test pieces with a coating thickness of 50-65 μm were obtained. After the preparation was completed, the following tests were performed:

[0127] 1. High-pressure resistance test: The impact resistance of the specimens was measured according to the method in Appendix E of SY / T0315-2013. The impact energy values ​​of the specimens were 0.75J, 1.00J, 1.25J, 1.50J, 1.75J, 2.00J, 2.25J, 2.50J, 2.75J and 3.00J, respectively. The maximum impact energy value that each specimen could bear was recorded, and the results were recorded in Table 2.

[0128] 2. The coating adhesion of the specimens was measured according to the method in Appendix G of SY / T0315-2013. The immersion temperature of the specimens in the pretreatment was 70°C and the immersion time was 28 days. After the specimens were taken out and were still warm, a rectangle of about 30 mm × 15 mm was immediately scratched on the coating with a knife, penetrating the coating to reach the surface of the pipeline sample. After natural cooling for 1 hour, the tip of the knife was inserted under the coating from any corner of the rectangle, and the coating was pried off with a horizontal force. The tip of the knife was continuously pushed until all the coating in the rectangle was pried off or the coating showed obvious anti-pry performance. The test results were recorded in Table 2.

[0129] The grading standards are:

[0130] Level 1: The coating cannot be peeled off by prying;

[0131] Level 2: The coating peeled off is less than or equal to 50%;

[0132] Level 3: The coating is pried off by more than 50%, but the coating shows a certain degree of pry resistance;

[0133] Level 4: The coating can be easily peeled off into strips or large pieces;

[0134] Level 5: The coating is peeled off in one piece;

[0135] 3. High temperature resistance test: refer to the method in Appendix J of SY / T0315-2013 to measure the cathode peeling resistance of the specimen. The immersion temperature of the specimen in pretreatment is 150℃ and the immersion time is 28d. The time when the coating first cracks is observed and the observation time interval is 0.5d. The test results are recorded in Table 2.

[0136] Table 2

[0137]

[0138]

[0139] It can be seen from Table 2 that the first cracking time of Examples 1 and 2 can reach more than 18.5h, proving that the synergistic effect of bisphenol A epoxy resin and tetraglycidyl diaminodiphenylmethane can improve the corrosion resistance of the powder coating at high temperature and prolong the cracking time of the coating. The maximum impact energy value of Examples 1 and 2 can reach more than 2.25J, and the adhesion grade can reach level 3, proving that tetraglycidyl diaminodiphenylmethane can improve the crosslinking degree and mechanical strength of the powder coating, making the internal structure of the coating denser, and can withstand the pressure and impact force of the contents of the pipeline under high pressure conditions, reducing the possibility of cracking of the coating. In summary, the present application uses tetraglycidyl diaminodiphenylmethane and bisphenol A epoxy resin as the main ingredients of epoxy resin, which significantly improves the high temperature and high pressure resistance and corrosion resistance of the powder coating;

[0140] The maximum impact energy value of Example 3 is lower than that of Example 1, and the first cracking time of Example 4 is lower than that of Example 1, which proves that the present application further limits the weight ratio of bisphenol A epoxy resin and tetraglycidyl diaminodiphenylmethane, thereby improving the high temperature and high pressure resistance of the powder coating without affecting its corrosion resistance;

[0141] The maximum impact energy values ​​and adhesion levels of Examples 5-9 are significantly improved compared to Example 1, and the first cracking time is also increased to a certain extent, and it is proved that the present application replaces part of the bisphenol A type epoxy resin with a polyether type hyperbranched epoxy resin to effectively improve the corrosion resistance and high temperature and high pressure resistance of the powder coating;

[0142] The first cracking time of Example 7 is somewhat lower than that of Example 5, and the maximum impact energy value of Example 8 is somewhat lower than that of Example 5, which proves that the weight ratio of bisphenol A epoxy resin and polyether hyperbranched epoxy resin further specified in the present application can improve the high pressure resistance of the powder coating without affecting its corrosion resistance and heat resistance;

[0143] Although the maximum impact energy values ​​of Examples 10 and 11 are higher than those of Example 1, they are somewhat lower than those of Example 5, which proves that the polyether-type hyperbranched epoxy resin prepared by using octyl glycidyl ether as a raw material in the present application can effectively improve the high pressure resistance of the powder coating;

[0144] The first cracking time of Example 12 is significantly reduced compared with that of Example 1, which proves that the present application only replaces part of the bisphenol A type epoxy resin with a polyether type hyperbranched epoxy resin, which can effectively improve the high temperature and high pressure resistance of the powder coating without affecting the corrosion resistance of the powder coating;

[0145] The first cracking time of Example 13 is somewhat lower than that of Example 1, which proves that the polyether hyperbranched epoxy resin used in the present application to replace part of the bisphenol A epoxy resin can effectively improve the high temperature and high pressure resistance of the powder coating without affecting the corrosion resistance of the powder coating;

[0146] The first cracking time of Examples 14-21 is greater than that of Example 5, and the adhesion level and the maximum impact energy value do not change significantly, which proves that the present application adopts the modification treatment of bisphenol A epoxy resin, which significantly improves the heat resistance of the powder coating without affecting the high pressure resistance;

[0147] The first cracking time of Examples 16 and 17 is somewhat lower than that of Examples 14 and 15, which proves that the use of a stannous octoate catalyst with high catalytic activity in the present application significantly improves the conversion rate of the bisphenol A epoxy resin modification reaction and the purity of the modified bisphenol A epoxy resin, thereby improving the heat resistance of the modified bisphenol A epoxy resin;

[0148] The first cracking time of Examples 18-20 is significantly improved compared with Examples 14 and 15, which proves that the present application further limits the amount of stannous octoate catalyst to 0.5-1.5wt% of the amount of bisphenol A epoxy resin, while not affecting the heat resistance of the modified bisphenol A epoxy resin. The conversion rate of the modification reaction is improved, and the first cracking time of Example 20 is greater than that of Examples 18 and 19, which proves that the best effect is achieved when the amount of stannous octoate catalyst is 1.0wt% of the amount of bisphenol A epoxy resin;

[0149] The first cracking time of Example 21 is not significantly different from that of Examples 14 and 15, but its adhesion level and first cracking time are much lower than those of Examples 14 and 15, which proves that the present application uses diphenylsilanediol to modify the bisphenol A epoxy resin, which significantly improves its corrosion resistance at high temperature without affecting the high pressure resistance of the bisphenol A epoxy resin;

[0150] The adhesion levels of Examples 22 and 23 are significantly improved compared with Example 1, and the first cracking time is not significantly changed compared with Example 1. The first cracking time of Example 26 is slightly decreased compared with Examples 22 and 23, and the maximum impact energy value of Example 27 is slightly decreased compared with Examples 22 and 23. This proves that the present application uses a mixture of 1,3-cyclohexanedimethylamine and 4,4'-diaminodicyclohexylmethane as a curing agent, and the two can play a synergistic role, and improve its high pressure resistance without affecting the heat resistance and corrosion resistance of the powder coating;

[0151] The first cracking time of Examples 24 and 25 is somewhat lower than that of Examples 22 and 23, which proves that the weight ratio of 1,3-cyclohexanedimethylamine and 4,4'-diaminodicyclohexylmethane is further specified in the present application, which can further improve the high pressure resistance of the powder coating without affecting its heat resistance and corrosion resistance;

[0152] The maximum impact energy value of comparative example 1 is smaller than that of example 1, while the first cracking time of comparative example 2 is smaller than that of example 1, which proves that the present application adopts a mixture of glycidylamine type epoxy resin and glycidyl ether type epoxy resin in a certain weight ratio as the main material of epoxy resin, so that it has high resistance to high temperature and high pressure under the condition of high corrosion resistance.

[0153] The embodiments of this specific implementation method are all preferred embodiments of the present application, and are not intended to limit the protection scope of the present application. Therefore, all equivalent changes made based on the structure, shape, and principle of the present application should be included in the protection scope of the present application.

Claims

1. A high temperature and high pressure resistant and corrosion resistant powder coating, Features: The raw materials used include the following components in parts by weight: 190-225 parts of epoxy resin main material; 50-60 parts of curing agent; 30-35 parts of reinforcing agent; 3-5 parts of other auxiliary agents; 80-100 parts of filler; 3-5 parts of pigment; the epoxy resin main material includes glycidylamine type epoxy resin and glycidyl ether type epoxy resin, and the curing agent includes 1,3-cyclohexanedimethylamine and 4,4'-diaminodicyclohexylmethane in a weight ratio of (4-5): (2.5-2.8).

2. A high temperature and high pressure resistant corrosion resistant powder coating according to claim 1, Features: The weight ratio of the glycidylamine epoxy resin to the glycidylether epoxy resin is (5-8):(15-17).

3. A high temperature and high pressure resistant and corrosion resistant powder coating according to claim 2, Features: The glycidyl ether epoxy resin comprises bisphenol A epoxy resin and polyether hyperbranched epoxy resin in a weight ratio of (505-508):(55.8-56.7).

4. The high temperature and high pressure resistant and corrosion resistant powder coating according to claim 3, Features: The polyether type hyperbranched epoxy resin is prepared by the following steps: S1. Add a catalytic amount of a catalyst to a mixture of 3,5-dihydroxybenzoic acid and octyl glycidyl ether in a weight ratio of (154-160): (168-180), mix well and dissolve in a solvent, continue to introduce nitrogen and react at 85-95° C. for 4.5-5.5 hours, then wash and dry to obtain a primary product; S2. Add trimethylolpropane triglycidyl ether and a catalytic amount of a catalyst to the primary product, mix well and dissolve in a solvent, wherein the amount of trimethylolpropane triglycidyl ether is 585-589wt% of the amount of 3,5-dihydroxybenzoic acid, continuously introduce nitrogen and react at 85-95°C for 4.5-5.5h, wash and dry to obtain a polyether hyperbranched epoxy resin.

5. The high temperature and high pressure resistant and corrosion resistant powder coating according to claim 3, Features: The bisphenol A epoxy resin is modified by the following steps: Bisphenol A epoxy resin and diphenylsilanediol in a weight ratio of (100-120): (30-33) are uniformly mixed, and a catalytic amount of stannous octoate catalyst is added, and the mixture is reacted at a temperature of 110-130° C. for 2.0-2.5 hours to obtain a modified bisphenol A epoxy resin.

6. The high temperature and high pressure resistant and corrosion resistant powder coating according to claim 5, Features: The amount of the stannous octoate catalyst added is 0.5-1.5wt% of the amount of the bisphenol A epoxy resin used.

7. The high temperature and high pressure resistant and corrosion resistant powder coating according to claim 6, Features: The amount of the stannous octoate catalyst added is 1.0wt% of the amount of the bisphenol A epoxy resin used.

8. The high temperature and high pressure resistant and corrosion resistant powder coating according to claim 1, Features: The other auxiliary agents include one or more of stabilizers, defoamers and leveling agents.

9. A method for preparing the high temperature and high pressure resistant corrosion resistant powder coating according to any one of claims 1 to 8, The following steps are involved: All the raw materials are mixed evenly, melt-extruded at a temperature of 140-155° C., cooled, crushed, and sieved to obtain a high-temperature, high-pressure, and corrosion-resistant powder coating.

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