A polyurethane polyurea two-component coating composition, and a method for preparing and using the same

Abstract

The present application relates to a kind of polyurethane polyurea two-component coating compositions, including component A and component B, component A includes 5-30 parts of polyamine resin, 40-70 parts of polyol resin, 10-35 parts of first solvent, 0.5-3 parts of ultraviolet light absorber, 0.5-2 parts of light stabilizer and 0.1-3 parts of additional auxiliary agent by weight;Component B includes 40-85 parts of isocyanate curing agent and 15-60 parts of second solvent;The weight ratio of component A and component B is between 1:10-10:1.The polyurethane polyurea two-component coating compositions provided by the present application has the characteristics of high solid content, low viscosity, high weather resistance and low temperature rapid curing, and can be applied to the surface treatment of different types of substrates such as metal, concrete, plastic and composite material.The present application also relates to a kind of preparation method of the above-mentioned polyurethane polyurea two-component coating compositions and a substrate based on the coating compositions.

Description

Technical Field

[0001] The present invention relates to the technical field of coatings, in particular to a polyurethane-polyurea two-component coating composition, a preparation method thereof, and a substrate based on the coating composition. Background Art

[0002] Polyurethane coatings, with their excellent weather resistance, decorative properties, physical and mechanical properties, and chemical resistance, have been widely used in the fields of automotive coatings, industrial coatings, automotive refinishing paints, architectural coatings, and engineering coatings. However, most polyurethane coatings currently contain medium or low solids, and their VOC content is relatively high (VOC>420g / L), which is not conducive to environmental protection. Simultaneously, in polyurethane systems, catalysts, such as tin catalysts, must be added to improve reactivity. While catalyzing the reaction of hydroxyl groups with isocyanates, the catalysts also catalyze the reaction of isocyanates with water, generating gas and causing a decrease in material performance. Furthermore, tin metals are also not conducive to environmental protection. Failure to add a catalyst can greatly reduce the reaction rate of the polyurethane, affecting the coating's construction efficiency.

[0003] The polyurea coating system is completely different. It uses a polyamine resin as the active hydrogen component, which has extremely high reactivity with the isocyanate component and can quickly complete the reaction under low temperature conditions (even below 0°C) without any catalyst. At the same time, polyurea coatings can achieve high solids content or even 100% solids content, which is environmentally friendly. Polyurea coatings have excellent physical and chemical properties, such as high tensile strength, high elongation, good flexibility, wear resistance, aging resistance, corrosion resistance, and high thermal stability, and have been widely used in various fields. However, due to the rapid curing speed of polyurea coatings, the operating time after mixing the polyamine resin and isocyanate components is very short, and they can only be applied through two-component equipment of certain specifications, which seriously affects their application in construction.

[0004] In view of this, how to design a polyurethane-polyurea two-component coating composition that can combine the advantages and performance of polyurethane coatings and polyurea coatings to achieve characteristics such as high solid content, high weather resistance, and low-temperature rapid curing is a technical problem that needs to be urgently solved by relevant technical personnel in the industry. Summary of the Invention

[0005] To overcome the above-mentioned technical problems, the present invention provides a polyurethane-polyurea two-component coating composition, a preparation method thereof, and a substrate based on the coating composition. This coating composition exhibits high solids content, low viscosity, high weather resistance, and rapid low-temperature curing, making it suitable for surface treatment of various substrates, including metal, concrete, plastic, and composite materials. Furthermore, compared to polyurea coatings, this coating composition cures more slowly, resulting in a longer working life. Therefore, it is widely applicable in general industrial coatings, automotive coatings, automotive refinishing paints, waterproof coatings, engineering coatings, and tile caulking agents.

[0006] The first aspect of the present invention provides a polyurethane polyurea two-component coating composition, comprising component A and component B, wherein, in parts by weight,

[0007] Component A comprises: 5-30 parts of a polyamine resin, 40-70 parts of a polyol resin, 10-35 parts of a first solvent, 0.5-3 parts of an ultraviolet light absorber, 0.5-2 parts of a light stabilizer, and 0.1-3 parts of an additional auxiliary agent;

[0008] Component B includes: 40-85 parts of an isocyanate curing agent and 15-60 parts of a second solvent;

[0009] Wherein, the weight ratio of component A to component B is between 1:10 and 10:1.

[0010] Polyamine resin

[0011] In one embodiment of the present invention, the polyamine resin is selected from polyaspartic acid ester polyamine resin.

[0012] Furthermore, the polyaspartic acid ester polyamine resin is a secondary amino polyamine resin containing steric hindered groups, and its structure is shown in Figure (I), Figure (II), and Figure (III) below.

[0013] Preferably, the polyaspartic acid ester polyamine resin includes but is not limited to Desmophen NH1220, Desmophen NH1420, Desmophen NH1423 and Desmophen NH1520 commercially available from Bayer MaterialScience, or F220, F420, F520, F524 and F525 commercially available from Zhuhai Feiyang.

[0014]

[0015]

[0016] Polyol resin

[0017] In one embodiment of the present invention, the polyol resin is, for example but not limited to, at least one selected from the group consisting of hydroxyl-containing acrylic resin, hydroxyl-containing polyester resin, hydroxyl-containing polyether resin, and hydroxyl-containing silicone resin.

[0018] Furthermore, the hydroxyl-containing acrylic resin is polymerized from acrylic acid monomers, methacrylic acid monomers and derivatives thereof, including but not limited to Setalux 1907BA-75, TIRES2850, SETALUX 1774SS-65, SETALUX 1215BA-68, SETALUX 1274BA-70, SETALUX 91757VX-60, SETALUX 91795VX-60, SETALUX 61767VX-60, etc., commercially available from Allnex, or Joncryl 507, Joncryl 804, Joncryl 910, etc., commercially available from BASF.

[0019] Furthermore, the hydroxyl-containing polyester resin includes but is not limited to conventional saturated polyester polyols, polycaprolactone polyols, and polycarbonate diols. Preferably, the hydroxyl-containing polyester resin includes but is not limited to SETAL1612VS-60, SETAL 1715VX-74, SETAL 90173SS-50, SETAL 1603BA-78, SETAL 168SS-80, SETAL 82166SS-64, etc. commercially available from Allnex, or K-Flex XM-332, K-Flex 148, K-Flex XM-337, etc. commercially available from King Industries, Inc.

[0020] Furthermore, the hydroxyl-containing polyether resin includes but is not limited to Sovermol 750, Sovermol 805, Sovermol 819, etc. commercially available from BASF.

[0021] Isocyanate curing agent

[0022] In one embodiment of the present invention, the isocyanate curing agent is, for example, but not limited to, one or more of an aliphatic isocyanate monomer, an aliphatic isocyanate polymer, an alicyclic isocyanate monomer, an alicyclic isocyanate polymer, an aromatic isocyanate monomer, an aromatic isocyanate polymer, an isocyanate hybrid, and an isocyanate hybrid polymer.

[0023] Furthermore, the aliphatic isocyanate monomer is, for example but not limited to, one or more of tetramethylene 1,4-diisocyanate, hexamethylene 1,6-diisocyanate, 2,2,4-trimethylhexane 1,6-diisocyanate, ethylene diisocyanate, and 1,12-dodecane diisocyanate.

[0024] Furthermore, the aliphatic isocyanate polymer is an aliphatic isocyanate dimer or an aliphatic isocyanate trimer.

[0025] Furthermore, the alicyclic isocyanate monomer is, for example, but not limited to, one or more of isophorone diisocyanate, cyclobutane 1,3-diisocyanate, cyclohexane 1,3-diisocyanate, cyclohexane 1,4-diisocyanate, methylcyclohexyl diisocyanate, 4,4'-methylene dicyclohexyl diisocyanate, and hydrogenated diphenylmethane diisocyanate.

[0026] Furthermore, the alicyclic isocyanate polymer is an alicyclic isocyanate dimer or an alicyclic isocyanate trimer.

[0027] Furthermore, the aromatic isocyanate monomer is, for example, but not limited to, one or more of toluene 2,4-diisocyanate, toluene 2,6-diisocyanate, diphenylmethane 4,4'-diisocyanate, diphenylmethane 2,4'-diisocyanate, p-phenylene diisocyanate, biphenyl diisocyanate, 3,3'-dimethyl-4,4'-diphenylene diisocyanate, and hexahydrophenylene 1,3-diisocyanate.

[0028] Furthermore, the aromatic isocyanate polymer is an aromatic isocyanate dimer or an aromatic isocyanate trimer.

[0029] Furthermore, the isocyanate hybrid polymer is an isocyanate hybrid dimer or an isocyanate hybrid trimer.

[0030] Preferably, the isocyanate curing agent includes but is not limited to Desmodur N 3300, Desmodur N 3390, Desmodur N 3600, Desmodur N 3900 and Desmodur Z 4470 commercially available from Bayer MaterialScience, or HDT-90, HDT-100 and HDT-LV commercially available from Rhodia Group, or Basonat HI 100 commercially available from BASF.

[0031] solvent

[0032] In one embodiment of the present invention, the first solvent and the second solvent may be the same or different, including but not limited to toluene, xylene, acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, isophorone, butyl acetate, ethyl acetate, 3-ethoxyethyl propionate, propylene glycol methyl ether acetate, propylene glycol ethyl ether acetate, ethylene glycol butyl ether acetate, ethylene glycol ethyl ether acetate, No. 100 solvent oil, No. 150 solvent oil, No. 200 solvent oil, etc.

[0033] UV absorbers

[0034] In one embodiment of the present invention, the ultraviolet light absorber includes but is not limited to one or more of Tinuvin 328, Tinuvin 384-2, Tinuvin 900, Tinuvin 928, Tinuvin 1130, Tinuvin 400, Tinuvin 479, Tinuvin 477, and Tinuvin CarboProtect.

[0035] Light stabilizers

[0036] In one embodiment of the present invention, the light stabilizer includes but is not limited to one or more of Tinuvin 144, Tinuvin 123, Tinuvin 292, Tinuvin 440, and Tinuvin 622.

[0037] Additional additives

[0038] In one embodiment of the present invention, the additional additive in component A is selected from one or more of a substrate wetting agent, a wetting and dispersing agent, a leveling agent, and a rheological additive. Those skilled in the art will appreciate that the additive can be selected based on actual process requirements, and the scope of the present invention is not limited to the additives listed above.

[0039] The second aspect of the present invention provides a method for preparing the polyurethane-polyurea two-component coating composition according to the first aspect of the present invention, comprising the steps of:

[0040] (1) preparing component A: providing 5-30 parts of a polyamine resin, 40-70 parts of a polyol resin, 0.5-3 parts of an ultraviolet light absorber, 0.5-2 parts of a light stabilizer, and 0.1-3 parts of an additional auxiliary agent; and providing 10-35 parts of a first solvent, adding the above components under stirring, and stirring until the mixture is uniformly mixed to obtain component A;

[0041] (2) Preparing component B: providing 40-85 parts of an isocyanate curing agent and 15-60 parts of a second solvent, flushing an inert gas into the second solvent, and adding the components under stirring, stirring until the mixture is uniform, thereby obtaining component B;

[0042] (3) Component A and component B are fully mixed in a weight ratio of 1:10 to 10:1 to obtain the polyurethane polyurea two-component coating composition.

[0043] The viscosity of the polyurethane-polyurea two-component coating composition at 23° C. is in the range of 100 to 20,000 mPa·s, preferably in the range of 100-10,000 mPa·s, and more preferably in the range of 100-5,000 mPa·s.

[0044] The third aspect of the present invention provides a substrate whose surface is coated with the polyurethane-polyurea two-component coating composition described in the first aspect of the present invention, wherein the substrate includes but is not limited to one or more of metal, concrete, plastic, and composite materials.

[0045] In one embodiment of the present invention, the coating method includes but is not limited to air spraying, airless spraying, online electrostatic spraying or in-mold coating.

[0046] Beneficial effects of the present invention

[0047] Compared with the prior art, the technical solution provided by the present invention has the following advantages:

[0048] The polyurethane-polyurea two-component coating composition of the present invention utilizes a polyamine resin and a polyol resin as component A, which undergo a curing reaction with an isocyanate curing agent as component B. The resulting coating composition exhibits excellent physical and mechanical properties, adhesion, flexibility, high solid content, and low-temperature rapid curing. Furthermore, the polyurethane-polyurea two-component coating composition of the present invention can be combined with an ultraviolet light absorber and a light stabilizer to impart excellent weather resistance to the coating composition, providing excellent protection for the substrate surface. The solid content and curing rate of the coating composition can be controlled by adjusting the type and ratio of the polyol and polyamine resins. Furthermore, the hardness and flexibility of the coating can be adjusted by adjusting the ratio of the hydroxylated acrylic resin, hydroxylated polyester resin, and / or hydroxylated polyether resin in the polyol resin of the coating composition.

[0049] This coating composition has a long workability time, comparable to conventional polyurethane coating compositions, significantly improving the workability of traditional polyurea coatings. Furthermore, it can achieve rapid curing at low temperatures of 60-90 degrees Celsius, significantly improving the curing efficiency of the coating composition and saving energy. DETAILED DESCRIPTION

[0050] The specific embodiments of the present invention are described in detail below. It will be understood by those skilled in the art that the present invention is not limited to the embodiments described below, and the technical concept of the present invention can be implemented in combination with other known technologies or other technologies with the same functions as known technologies.

[0051] The specific embodiments of the present invention are described in detail below.

[0052] Example 1

[0053] In this embodiment, a polyurethane-polyurea two-component coating composition 1 is provided. The polyurethane-polyurea two-component coating composition 1 includes component A and component B. The compositions of component A and component B are as follows, in parts by weight:

[0054] Table 1.1 Composition of component A in Example 1

[0055] Components name Number of copies Polyol resin 1 SETALUX 1215BA-68 50 Polyol resin 2 SETAL 1603BA-78 15 Polyamine resin Desmophen NH1420 5 First solvent 1 Butyl acetate 18 First solvent 2 Propylene glycol methyl ether acetate 10 Additional additive 1 Substrate wetting agents 0.3 Additional additives 2 Leveling agent 0.2 UV absorbers 1 Light stabilizers 0.5

[0056] Table 1.2 Composition of component B in Example 1

[0057] Components name Number of copies Isocyanate curing agent Desmodur N 3390 80 Second solvent 1 Butyl acetate 10 Second solvent 2 Propylene glycol methyl ether acetate 10

[0058] The specific steps of the preparation method and application of the polyurethane-polyurea two-component coating composition 1 are as follows:

[0059] (1) Under stirring, add SETALUX 1215BA-68, SETAL 1603BA-78, Desmophen NH1420, butyl acetate, and propylene glycol methyl ether acetate in sequence to the main container and stir for 15-20 minutes at a stirring rate of 500-1500 rpm to mix them evenly. Then, add the substrate wetting agent, leveling agent, ultraviolet light absorber, and light stabilizer and continue stirring for 20-30 minutes to obtain component A. The viscosity of component A at 23°C is in the range of 100-20000 mPa·s.

[0060] (2) Nitrogen is injected into a composite solvent of butyl acetate and propylene glycol methyl ether acetate, and isocyanate curing agent Desmodur N 3390 is added under stirring, and stirred for 10-20 minutes to obtain component B. The mass percentage of the isocyanate curing agent in component B is 60-90%.

[0061] (3) When in use, component A and component B are fully mixed in a weight ratio of 1:10 to 10:1 to obtain the coating composition 1.

[0062] (4) The coating composition 1 was applied to the epoxy-based carbon fiber composite material substrate and cured at 80 degrees Celsius for 60 minutes before the performance test was carried out. The relevant results are shown in Table 9.

[0063] Example 2

[0064] In this embodiment, a polyurethane-polyurea two-component coating composition 2 is provided. The polyurethane-polyurea two-component coating composition 2 includes component A and component B. The compositions of component A and component B are as follows, in parts by weight:

[0065] Table 2.1 Composition of Component A in Example 2

[0066] Components name Number of copies Polyol resin 1 SETALUX 1215BA-68 40 Polyol resin 2 SETAL 1603BA-78 15 Polyamine resin Desmophen NH1420 15 First solvent 1 Butyl acetate 18 First solvent 2 Propylene glycol methyl ether acetate 10 Additional additive 1 Substrate wetting agents 0.3 Additional additives 2 Leveling agent 0.2 UV absorbers 1 Light stabilizers 0.5

[0067] Table 2.2 Composition of component B in Example 2

[0068] Components name Number of copies Isocyanate curing agent Desmodur N 3390 80 Second solvent 1 Butyl acetate 10 Second solvent 2 Propylene glycol methyl ether acetate 10

[0069] The specific steps of the preparation method and application of the polyurethane-polyurea two-component coating composition 2 are as follows:

[0070] (1) Under stirring, add SETALUX 1215BA-68, SETAL 1603BA-78, Desmophen NH1420, butyl acetate, and propylene glycol methyl ether acetate in sequence to the main container and stir for 15-20 minutes at a stirring rate of 500-1500 rpm to mix them evenly. Then, add the substrate wetting agent, leveling agent, ultraviolet light absorber, and light stabilizer and continue stirring for 20-30 minutes to obtain component A. The viscosity of component A at 23°C is in the range of 100-20000 mPa·s.

[0071] (2) Nitrogen is injected into a composite solvent of butyl acetate and propylene glycol methyl ether acetate, and isocyanate curing agent Desmodur N 3390 is added under stirring, and stirred for 10-20 minutes to obtain component B. The mass percentage of the isocyanate curing agent in component B is 60-90%.

[0072] (3) When in use, component A and component B are fully mixed in a weight ratio of 1:10 to 10:1 to obtain the coating composition 2.

[0073] (4) The coating composition 2 was applied to the epoxy-based carbon fiber composite material substrate and cured at 80 degrees Celsius for 60 minutes before the performance test was carried out. The relevant results are shown in Table 9.

[0074] Example 3

[0075] In this embodiment, a polyurethane-polyurea two-component coating composition 3 is provided. The polyurethane-polyurea two-component coating composition 3 includes component A and component B. The compositions of component A and component B are as follows, in parts by weight:

[0076] Table 3.1 Composition of Component A in Example 3

[0077] Components name Number of copies Polyol resin 1 SETALUX 1215BA-68 40 Polyol resin 2 SETAL 1603BA-78 15 Polyamine resin Desmophen NH1520 15 First solvent 1 Butyl acetate 18 First solvent 2 Propylene glycol methyl ether acetate 10 Additional additive 1 Substrate wetting agents 0.3 Additional additives 2 Leveling agent 0.2 UV absorbers 1 Light stabilizers 0.5

[0078] Table 3.2 Composition of component B in Example 3

[0079] Components name Number of copies Isocyanate curing agent Desmodur N 3390 80 Second solvent 1 Butyl acetate 10 Second solvent 2 Propylene glycol methyl ether acetate 10

[0080] The specific steps of the preparation method and application of the polyurethane-polyurea two-component coating composition 3 are as follows:

[0081] (1) Under stirring, add SETALUX 1215BA-68, SETAL 1603BA-78, Desmophen NH1520, butyl acetate, and propylene glycol methyl ether acetate in sequence to the main container and stir for 15-20 minutes at a stirring rate of 500-1500 rpm to mix them evenly. Then, add the substrate wetting agent, leveling agent, ultraviolet light absorber, and light stabilizer and continue stirring for 20-30 minutes to obtain component A. The viscosity of component A at 23°C is in the range of 100-20000 mPa·s.

[0082] (2) Nitrogen is injected into a composite solvent of butyl acetate and propylene glycol methyl ether acetate, and isocyanate curing agent Desmodur N 3390 is added under stirring, and stirred for 10-20 minutes to obtain component B. The mass percentage of the isocyanate curing agent in component B is 60-90%.

[0083] (3) When in use, component A and component B are fully mixed in a weight ratio of 1:10 to 10:1 to obtain the coating composition 3.

[0084] (4) The coating composition 3 was applied to the epoxy-based carbon fiber composite material substrate and cured at 80 degrees Celsius for 60 minutes before the performance test was carried out. The relevant results are shown in Table 9.

[0085] Example 4

[0086] In this embodiment, a polyurethane-polyurea two-component coating composition 4 is provided. The polyurethane-polyurea two-component coating composition 3 includes component A and component B. The compositions of component A and component B are as follows, in parts by weight:

[0087] Table 4.1 Composition of Component A in Example 4

[0088] Components name Number of copies Polyol resin 1 SETALUX 1215BA-68 40 Polyol resin 2 SETAL 1603BA-78 15 Polyamine resin Desmophen NH1220 15 First solvent 1 Butyl acetate 18 First solvent 2 Propylene glycol methyl ether acetate 10 Additional additive 1 Substrate wetting agents 0.3 Additional additives 2 Leveling agent 0.2 UV absorbers 1 Light stabilizers 0.5

[0089] Table 4.2 Composition of component B in Example 4

[0090] Components name Number of copies Isocyanate curing agent Desmodur N 3390 80 Second solvent 1 Butyl acetate 10 Second solvent 2 Propylene glycol methyl ether acetate 10

[0091] The specific steps of the preparation method and application of the polyurethane-polyurea two-component coating composition 4 are as follows:

[0092] (1) Under stirring, add SETALUX 1215BA-68, SETAL 1603BA-78, Desmophen NH1220, butyl acetate, and propylene glycol methyl ether acetate in sequence to the main container and stir for 15-20 minutes at a stirring rate of 500-1500 rpm to mix them evenly. Then, add the substrate wetting agent, leveling agent, ultraviolet light absorber, and light stabilizer and continue stirring for 20-30 minutes to obtain component A. The viscosity of component A at 23°C is in the range of 100-20000 mPa·s.

[0093] (2) Nitrogen is injected into a composite solvent of butyl acetate and propylene glycol methyl ether acetate, and isocyanate curing agent Desmodur N 3390 is added under stirring, and stirred for 10-20 minutes to obtain component B. The mass percentage of the isocyanate curing agent in component B is 60-90%.

[0094] (3) When in use, component A and component B are fully mixed in a weight ratio of 1:10 to 10:1 to obtain the coating composition 4.

[0095] (4) The coating composition 4 was applied to the epoxy-based carbon fiber composite material substrate and cured at 80 degrees Celsius for 60 minutes before the performance test was carried out. The relevant results are shown in Table 9.

[0096] Comparative Example 1

[0097] In this comparative example 1, a polyurethane coating composition 5 is provided, which comprises component A and component B, wherein the compositions of component A and component B are as follows, in parts by weight:

[0098] Table 5.1 Composition of component A in comparative example 1

[0099] Components name Number of copies Polyol resin 1 SETALUX 1215BA-68 55 Polyol resin 2 SETAL 1603BA-78 15 First solvent 1 Butyl acetate 18 First solvent 2 Propylene glycol methyl ether acetate 10 Additional additive 1 Substrate wetting agents 0.3 Additional additives 2 Leveling agent 0.2 UV absorbers 1 Light stabilizers 0.5

[0100] Table 5.2 Composition of component B in comparative example 1

[0101] Components name Number of copies Isocyanate curing agent Desmodur N 3390 80 Second solvent 1 Butyl acetate 10 Second solvent 2 Propylene glycol methyl ether acetate 10

[0102] It should be noted that: in this example, component A contains only polyol resin and does not contain polyamine resin, so it is not within the scope of the present invention, and this example is comparative example 1.

[0103] The specific steps of the preparation method and application of the polyurethane coating composition 5 are as follows:

[0104] (1) Under stirring, add SETALUX 1215BA-68, SETAL 1603BA-78, butyl acetate and propylene glycol methyl ether acetate in sequence to the main container and stir for 15-20 minutes at a stirring rate of 500-1500 rpm to mix them evenly. Then, add the substrate wetting agent, leveling agent, ultraviolet light absorber and light stabilizer and continue stirring for 20-30 minutes to obtain component A. The viscosity of component A at 23°C is in the range of 100-20000 mPa·s.

[0105] (2) Nitrogen is injected into a composite solvent of butyl acetate and propylene glycol methyl ether acetate, and isocyanate curing agent Desmodur N 3390 is added under stirring, and stirred for 10-20 minutes to obtain component B. The mass percentage of the isocyanate curing agent in component B is 60-90%.

[0106] (3) When in use, component A and component B are fully mixed in a weight ratio of 1:10 to 10:1 to obtain the coating composition 5.

[0107] (4) The coating composition 5 was applied to the epoxy-based carbon fiber composite material substrate and cured at 80 degrees Celsius for 60 minutes before the performance test was carried out. The relevant results are shown in Table 9.

[0108] Comparative Example 2

[0109] In this comparative example 2, a polyurea coating composition 6 is provided. The polyurea coating composition 6 includes component A and component B. The compositions of component A and component B are as follows, in parts by weight:

[0110] Table 6.1 Composition of component A in comparative example 2

[0111] Components name Number of copies Polyamine resin Desmophen NH1420 70 First solvent 1 Butyl acetate 18 First solvent 2 Propylene glycol methyl ether acetate 10 Additional additive 1 Substrate wetting agents 0.3 Additional additives 2 Leveling agent 0.2 UV absorbers 1 Light stabilizers 0.5

[0112] Table 6.2 Composition of component B in comparative example 2

[0113] Components name Number of copies Isocyanate curing agent Desmodur N 3390 80 Second solvent 1 Butyl acetate 10 Second solvent 2 Propylene glycol methyl ether acetate 10

[0114] It should be noted that: in this example, component A only contains polyamine resin and does not contain polyol resin, so it is not within the scope of the present invention, and thus this example is comparative example 2.

[0115] The specific steps of the preparation method and application of the polyurea coating composition 6 are as follows:

[0116] (1) While stirring, add Desmophen NH1420, butyl acetate, and propylene glycol methyl ether acetate in sequence to the main container and stir for 15-20 minutes at a stirring rate of 500-1500 rpm to mix them evenly. Then, add the substrate wetting agent, leveling agent, ultraviolet light absorber, and light stabilizer and continue stirring for 20-30 minutes to obtain component A. The viscosity of component A at 23°C is in the range of 100-20000 mPa·s.

[0117] (2) Nitrogen is injected into a composite solvent of butyl acetate and propylene glycol methyl ether acetate, and isocyanate curing agent Desmodur N 3390 is added under stirring, and stirred for 10-20 minutes to obtain component B. The mass percentage of the isocyanate curing agent in component B is 60-90%.

[0118] (3) When in use, component A and component B are fully mixed in a weight ratio of 1:10 to 10:1 to obtain the coating composition 6.

[0119] (4) The coating composition 6 was applied to the epoxy-based carbon fiber composite material substrate and cured at 80 degrees Celsius for 60 minutes before the performance test was carried out. The relevant results are shown in Table 9.

[0120] Comparative Example 3

[0121] In this comparative example 3, a polyurethane-polyurea two-component coating composition 7 is provided. The polyurethane-polyurea two-component coating composition 7 comprises component A and component B. The compositions of component A and component B are as follows, in parts by weight:

[0122] Table 7.1 Composition of component A in comparative example 3

[0123] Components name Number of copies Polyol resin 1 SETALUX 1215BA-68 15 Polyol resin 2 SETAL 1603BA-78 15 Polyamine resin Desmophen NH1520 40 First solvent 1 Butyl acetate 18 First solvent 2 Propylene glycol methyl ether acetate 10 Additional additive 1 Substrate wetting agents 0.3 Additional additives 2 Leveling agent 0.2 UV absorbers 1 Light stabilizers 0.5

[0124] Table 7.2 Composition of component B in comparative example 3

[0125] Components name Number of copies Isocyanate curing agent Desmodur N 3390 80 Second solvent 1 Butyl acetate 10 Second solvent 2 Propylene glycol methyl ether acetate 10

[0126] It should be noted that: in this example, the amount of polyol resin in component A is less than that of polyamine resin, and therefore it is not within the scope of the present invention, so this example is comparative example 3.

[0127] The specific steps of the preparation method and application of the polyurethane-polyurea two-component coating composition 7 are as follows:

[0128] (1) Under stirring, add SETALUX 1215BA-68, SETAL 1603BA-78, Desmophen NH1520, butyl acetate, and propylene glycol methyl ether acetate in sequence to the main container and stir for 15-20 minutes at a stirring rate of 500-1500 rpm to mix them evenly. Then, add the substrate wetting agent, leveling agent, ultraviolet light absorber, and light stabilizer and continue stirring for 20-30 minutes to obtain component A. The viscosity of component A at 23°C is in the range of 100-20000 mPa·s.

[0129] (2) Nitrogen is injected into a composite solvent of butyl acetate and propylene glycol methyl ether acetate, and isocyanate curing agent Desmodur N 3390 is added under stirring, and stirred for 10-20 minutes to obtain component B. The mass percentage of the isocyanate curing agent in component B is 60-90%.

[0130] (3) When in use, component A and component B are fully mixed in a weight ratio of 1:10 to 10:1 to obtain the coating composition 3.

[0131] (4) The coating composition 7 was applied to the epoxy-based carbon fiber composite material substrate and cured at 80 degrees Celsius for 60 minutes before the performance test was carried out. The relevant results are shown in Table 7.

[0132] Comparative Example 4

[0133] In this comparative example 4, a polyurethane-polyurea two-component coating composition 8 is provided. The polyurethane-polyurea two-component coating composition 8 comprises component A and component B. The compositions of component A and component B are as follows, in parts by weight:

[0134] Table 8.1 Composition of component A in comparative example 4

[0135]

[0136]

[0137] Table 8.2 Composition of component B in comparative example 4

[0138] Components name Number of copies Isocyanate curing agent Desmodur N 3390 80 Second solvent 1 Butyl acetate 10 Second solvent 2 Propylene glycol methyl ether acetate 10

[0139] It should be noted that: in this example, the amount of polyol resin in component A is still less than that of polyamine resin, and therefore it is not within the scope of the present invention, so this example is comparative example 4.

[0140] The specific steps of the preparation method and application of the polyurethane-polyurea two-component coating composition 8 are as follows:

[0141] (1) Under stirring, add SETALUX 1215BA-68, SETAL 1603BA-78, Desmophen NH1520, butyl acetate, and propylene glycol methyl ether acetate in sequence to the main container and stir for 15-20 minutes at a stirring rate of 500-1500 rpm to mix them evenly. Then, add the substrate wetting agent, leveling agent, ultraviolet light absorber, and light stabilizer and continue stirring for 20-30 minutes to obtain component A. The viscosity of component A at 23°C is in the range of 100-20000 mPa·s.

[0142] (2) Nitrogen is injected into a composite solvent of butyl acetate and propylene glycol methyl ether acetate, and isocyanate curing agent Desmodur N 3390 is added under stirring, and stirred for 10-20 minutes to obtain component B. The mass percentage of the isocyanate curing agent in component B is 60-90%.

[0143] (3) When in use, component A and component B are fully mixed in a weight ratio of 1:10 to 10:1 to obtain the coating composition 8.

[0144] (4) The coating composition 8 was applied to the epoxy-based carbon fiber composite material substrate and cured at 80 degrees Celsius for 60 minutes before the performance test was carried out. The relevant results are shown in Table 9.

[0145] Comparison results

[0146] The performance test results obtained from the above embodiments and comparative examples are shown in Table 9 below.

[0147] Table 9. Performance test results of each coating composition on carbon fiber composite material samples

[0148]

[0149] The results in Table 9 above show that the theoretical VOC values ​​of the coating compositions of Examples 1 and 2 are 430 and 400 g / L, respectively, and their pencil hardness values ​​are 2B and HB, respectively. This demonstrates that increasing the polyamine resin content can reduce the VOC value of the coating composition to meet environmental protection requirements of less than 420 g / L, while also significantly improving the hardness of the paint film. However, this also reduces the operability of the coating composition from 3 hours to 1 hour, which may affect its application. By adjusting the type of polyamine resin in Examples 2, 3, and 4, it was found that while maintaining the VOC value, the operability of Example 2 could reach 2 hours, while the operability of Example 4 was less than 30 minutes.

[0150] Comparative Example 1 is a polyurethane coating composition without a polyamine resin. Although the operability time is greater than 4 hours, its drying speed is slow, the theoretical VOC reaches 440 g / L, and the hardness is significantly lower than that of other samples.

[0151] Comparative Example 2 is a polyurea coating composition without polyol resin. Although it has good performance and a theoretical VOC of only 300 g / L, its operable time is less than 30 minutes, which seriously affects its use in construction.

[0152] In Comparative Examples 3 and 4, the amount of polyol resin was less than that of polyamine resin, resulting in a workable time of 2 and 3 hours, respectively, for the polyurea coating compositions. However, the drying speed was slow. After baking at 80°C for 1 hour, the paint films were clearly not completely dry, with hardnesses of less than 6B in both cases.

[0153] Through the above comparison, it can be found that Example 3 can have good physical properties and substrate pore filling properties while ensuring an operable time of 2 hours.

[0154] The present invention has been described by the above-mentioned embodiments. The above embodiments are intended only to illustrate the technical solutions of the present invention and are not intended to limit the present invention. Any technical solutions that can be derived by those skilled in the art through logical analysis, reasoning, or limited experimentation based on the concepts of the present invention shall be within the scope of protection of the present invention.

Claims

1. A polyurethane-polyurea two-component coating composition, characterized in that: The polyurethane polyurea two-component coating composition comprises component A and component B, in parts by weight, Component A consists of the following components: Component B consists of the following components: 80 parts of isocyanate curing agent Desmodur N 3390; Second solvent 1: 10 parts of butyl acetate; Second solvent 2: 10 parts of propylene glycol methyl ether acetate.

2. A method for preparing the polyurethane-polyurea two-component coating composition according to claim 1, comprising the following steps: (1) Under stirring, polyol resin 1 SETALUX 1215BA-68, polyol resin 2 SETAL 1603BA-78, polyamine resin Desmophen NH1520, first solvent 1 butyl acetate and first solvent 2 propylene glycol methyl ether acetate are added to the main container in sequence, and stirred for 15-20 minutes at a stirring rate of 500-1500 rpm to mix them evenly. Then, a substrate wetting agent, a leveling agent, an ultraviolet light absorber and a light stabilizer are added and stirred for 20-30 minutes to obtain component A; wherein the viscosity of component A at 23° C. is in the range of 100-20000 mPa·s; (2) nitrogen is introduced into a composite solvent of a second solvent 1, butyl acetate, and a second solvent 2, propylene glycol methyl ether acetate, and isocyanate curing agent Desmodur N 3390 is added under stirring, and stirred for 10-20 minutes to obtain component B; wherein the mass percentage of the isocyanate curing agent in component B is 60-90%; (3) component A and component B are fully mixed in any ratio between 1:10 and 10:1 by weight to obtain the polyurethane polyurea two-component coating composition.

3. A substrate, characterized in that The surface of the substrate is coated with the polyurethane-polyurea two-component coating composition according to claim 1, and the substrate comprises one or more of metal, concrete, plastic, and composite materials.

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