A high temperature resistant UV coating composition and a method for preparing the same

Abstract

The application discloses a kind of high-temperature-resistant UV coating compositions and preparation method thereof, including the following weight parts of raw material composition: triazine ring group modified polyurethane prepolymer 55~65 parts, siloxane group modified polyurethane prepolymer 25~35 parts, composite modified filler 2.5~7 parts, active diluent 15~20 parts, organic solvent 35~50 parts, photoinitiator 3~5 parts, antioxidant 1~2 parts, defoaming agent 0.2~0.5 parts and levelling agent 0.2~0.5 parts;UV coating composition prepared UV coating has excellent long-term high-temperature resistance, can satisfy extreme high-temperature scene demand.

Description

Technical Field

[0001] This invention relates to a high-temperature resistant UV coating composition and its preparation method, belonging to the field of UV curing coating technology. Background Technology

[0002] Polyurethane UV coatings utilize ultraviolet (UV) light to initiate a photopolymerization reaction, achieving a rapid transformation from a liquid to a solid state. They can be applied to substrates such as wood, metal, plastic, and glass, and are widely used in electronics, automotive, furniture, and stone protection industries. Polyurethane UV coatings are environmentally friendly due to their fast curing speed and low VOC emissions.

[0003] Polyurethane UV coatings are used in some high-temperature applications: such as providing high hardness and wear resistance in heat-exposed areas like batteries and processors on mobile phone / computer casings; extending service life by balancing flexibility and heat resistance in areas exposed to high summer temperatures, such as dashboards and seat armrests in automotive interiors; and providing surface protection as high-temperature resistant coatings for tools, pipes, and other equipment components. Although traditional polyurethane UV coatings have some applications in these high-temperature fields, their temperature resistance range is typically -40℃ to 120℃. If the long-term operating temperature exceeds 70℃, problems such as deformation, delamination, cracking, peeling, and performance degradation will occur. Due to insufficient long-term temperature resistance, traditional polyurethane UV coatings cannot meet the needs of extreme high-temperature scenarios. Summary of the Invention

[0004] To address at least one problem existing in the prior art, the present invention provides a high-temperature resistant UV coating composition and its preparation method. The UV coating prepared from the UV coating composition has excellent long-term high-temperature resistance and can meet the requirements of extreme high-temperature scenarios.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: a high-temperature resistant UV coating composition, comprising the following raw materials in parts by weight: 55-65 parts of triazine cyclomodified polyurethane prepolymer, 25-35 parts of siloxane-modified polyurethane prepolymer, 2.5-7 parts of composite modified filler, 15-20 parts of reactive diluent, 35-50 parts of organic solvent, 3-5 parts of photoinitiator, 1-2 parts of antioxidant, 0.2-0.5 parts of defoamer, and 0.2-0.5 parts of leveling agent.

[0006] Preferably, the composite modified filler is composed of a mixture of modified fumed silica and carboxylated multi-walled carbon nanotubes.

[0007] Preferably, the triazine cyclomodified polyurethane prepolymer is prepared by polypentyl adipate-1,6-hexanediol ester diol, dicyclohexylmethane diisocyanate, dibutyltin dilaurate, 2,2-dimethylolpropionic acid, and a triazine cyclomodifier.

[0008] Preferably, the triazine cyclomodifier is one of 2,4,6-tris[(p-carboxyphenyl)amino]-1,3,5-triazine or 2,4,6-tris(4-aminophenyl)-1,3,5-triazine.

[0009] Preferably, the specific preparation process of the triazine cyclomodified polyurethane prepolymer is as follows:

[0010] S-1. Under nitrogen protection, dry poly(neopentyl adipate)-1,6-hexanediol adipate, dicyclohexylmethane diisocyanate, and dibutyltin dilaurate are mixed and reacted at 85-90℃ for 3-4 hours. Then, 2,2-dimethylolpropionic acid is added, and the reaction is continued for 1-2 hours to obtain polyurethane prepolymer I.

[0011] S-2. Add a triazine cyclomodifier to polyurethane prepolymer I, react at 80~85℃ for 2~3h, then add triethylamine to neutralize, to obtain siloxane-modified polyurethane prepolymer.

[0012] Preferably, the mass ratio of the poly(neopentyl adipate)-1,6-hexanediol ester diol, dicyclohexylmethane diisocyanate, dibutyltin dilaurate, 2,2-dimethylolpropionic acid, and triazine cyclomodifier is 1:0.4~0.5:0.002~0.003:0.04~0.06:0.1~0.2.

[0013] Preferably, the siloxane-modified polyurethane prepolymer is prepared by polytetrahydrofuran ether diol, isophorone diisocyanate, dibutyltin dilaurate, 2,2-dimethylolpropionic acid, and hydroxyl-terminated polydimethylsiloxane.

[0014] Preferably, the specific preparation process of the siloxane-modified polyurethane prepolymer is as follows:

[0015] s1. Under nitrogen protection, dry polytetrahydrofuran ether diol, isophorone diisocyanate and dibutyltin dilaurate are mixed and reacted at 70~75℃ for 2~3h. Then 2,2-dimethylolpropionic acid is added and the reaction is continued for 2~3h to obtain polyurethane prepolymer II.

[0016] s2. Add dry hydroxyl-terminated polydimethylsiloxane to polyurethane prepolymer II, react at 80~85℃ for 2~3h, add triethylamine to neutralize, and obtain siloxane-modified polyurethane prepolymer.

[0017] Preferably, the mass ratio of polytetrahydrofuran ether diol, isophorone diisocyanate, dibutyltin dilaurate, 2,2-dimethylolpropionic acid and hydroxyl-terminated polydimethylsiloxane is 1:0.5~0.6:0.002~0.003:0.06~0.08:0.2~0.3.

[0018] Preferably, the composite modified filler is composed of modified fumed silica and carboxylated multi-walled carbon nanotubes in a mass ratio of 2 to 3:2.

[0019] Preferably, the modified fumed silica is obtained by first activating fumed silica with plasma and then treating it with a coupling agent.

[0020] Preferably, the carboxylated multi-walled carbon nanotubes are obtained by treating multi-walled carbon nanotubes with concentrated sulfuric acid, an activator, and an oxidant.

[0021] Preferably, the preparation process of modified fumed silica is as follows: first, fumed silica is activated by plasma, then dispersed in an ethanol solution containing 2 wt% silane coupling agent, then heated to 65°C and stirred for 2-3 hours, and then dried to obtain modified fumed silica.

[0022] Preferably, the mass ratio of the fumed silica to the silane coupling agent is 3:2.

[0023] Preferably, the original particle size of the fumed silica is 15~25nm.

[0024] Preferably, the preparation process of the carboxylated multi-walled carbon nanotubes is as follows: multi-walled carbon nanotubes are added to concentrated sulfuric acid at a temperature of 30-35°C under stirring. Potassium nitrate is added first for activation for 10-20 minutes, then potassium permanganate is added. The mixture is then ultrasonically stirred and oxidized at a power of 350-400W for 2-3 hours. The mixture is washed with water until pH 7 is reached and then dried to obtain carboxylated multi-walled carbon nanotubes.

[0025] Preferably, the mass ratio of concentrated sulfuric acid, multi-walled carbon nanotubes, potassium nitrate, and potassium permanganate is 200:4:4:5.

[0026] Preferably, the multi-walled carbon nanotubes have a particle size of 10-30 nm and a length of 10-15 μm.

[0027] Preferably, the reactive diluent is one or more of tricyclodecyl dimethyl diacrylate, pentaerythritol triacrylate, trimethylolpropane triacrylate, or tripropylene glycol diacrylate.

[0028] Preferably, the photoinitiator is one or more of 2-hydroxy-2-methyl-1-phenyl-1-propanone, 1-hydroxycyclohexylphenyl ketone, 2,2-dimethoxy-2-phenylacetophenone, and 2,4,6-trimethylbenzophenone.

[0029] Preferably, the antioxidants include antioxidant 1010 and antioxidant 168.

[0030] Preferably, the leveling agent is a polyester-modified polydimethylsiloxane type leveling agent KMT-5504.

[0031] Preferably, the defoamer is an organosilicon-based defoamer, BYK-306.

[0032] Preferably, the organic solvent is one of anhydrous ethanol, isopropanol, ethyl acetate, etc.

[0033] The present invention also provides a high-temperature resistant UV coating prepared from the above-mentioned UV coating composition. The preparation method includes the following steps: heating and mixing triazine cyclomodified polyurethane prepolymer, siloxane-modified polyurethane prepolymer and organic solvent to form an emulsion, then adding composite modified filler, reactive diluent, photoinitiator, antioxidant, defoamer and leveling agent, and dispersing at high speed to obtain a high-temperature resistant UV coating.

[0034] Beneficial effects of the present invention: The UV coating composition of the present invention uses a triazine cyclomodified polyurethane prepolymer prepared by polypentylene glycol-1,6-hexanediol adipate, dicyclohexylmethane diisocyanate, dibutyltin dilaurate, 2,2-dimethylolpropionic acid, and a triazine cyclomodifier, and a siloxane-modified polyurethane prepolymer prepared by polytetrahydrofuran ether diol, isophorone diisocyanate, dibutyltin dilaurate, 2,2-dimethylolpropionic acid, and hydroxyl-terminated polydimethylsiloxane. These two modified polyurethanes... The UV coating prepared by synergistically combining urethane prepolymer with a composite modified filler composed of modified fumed silica and carboxylated multi-walled carbon nanotubes improves the chemical and performance stability of the polyurethane crosslinking network, which is beneficial for improving the heat resistance and thermal cycling performance of the UV coating, giving it excellent high-temperature resistance and long-term high-temperature resistance. At the same time, this invention also improves the yellowing resistance of the UV coating. In addition, the adhesion between the UV coating prepared by the UV coating composition of this invention and materials such as PI and metal coatings is improved to a certain extent. Detailed Implementation

[0035] The following is a clear and complete description of the technical solutions in the implementation of this invention. The described embodiments are only a part of the embodiments of this invention, and not all of them. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention. Where specific conditions are not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall apply. Reagents, instruments, or components used that do not specify the manufacturer are all conventional products that can be purchased commercially.

[0036] Example 1: Preparation of triazine cyclomodified polyurethane prepolymer

[0037] The specific preparation process of the triazine cyclomodified polyurethane prepolymer in Example 1a is as follows:

[0038] S-1. Under nitrogen protection, dry poly(neopentyl adipate)-1,6-hexanediol adipate, dicyclohexylmethane diisocyanate, and dibutyltin dilaurate are mixed and reacted at 85-90℃ for 3 hours. Then, 2,2-dimethylolpropionic acid is added, and the reaction is continued for 2 hours to obtain polyurethane prepolymer I.

[0039] S-2. Add 2,4,6-tris[(p-carboxyphenyl)amino]-1,3,5-triazine to polyurethane prepolymer I, react at 80~85℃ for 2.5h, then add triethylamine to neutralize, to obtain siloxane-modified polyurethane prepolymer;

[0040] The composition of poly(neopentyl adipate)-1,6-hexanediol ester diol, dicyclohexylmethane diisocyanate, dibutyltin dilaurate, 2,2-dimethylolpropionic acid, and 2,4,6-tris[(p-carboxyphenyl)amino]-1,3,5-triazine is in a mass ratio of 1:0.45:0.002:0.06:0.15.

[0041] The specific preparation process of the triazine cyclomodified polyurethane prepolymer in Example 1b is as follows:

[0042] S-1. Under nitrogen protection, dry poly(neopentyl adipate)-1,6-hexanediol adipate, dicyclohexylmethane diisocyanate, and dibutyltin dilaurate are mixed and reacted at 85-90℃ for 3.5h. Then, 2,2-dimethylolpropionic acid is added, and the reaction is continued for 1.5h to obtain polyurethane prepolymer I.

[0043] S-2. Add 2,4,6-tris[(p-carboxyphenyl)amino]-1,3,5-triazine to polyurethane prepolymer I, react at 80~85℃ for 3h, and then add triethylamine to neutralize, to obtain siloxane-modified polyurethane prepolymer;

[0044] The composition of poly(neopentyl adipate)-1,6-hexanediol ester diol, dicyclohexylmethane diisocyanate, dibutyltin dilaurate, 2,2-dimethylolpropionic acid, and 2,4,6-tris[(p-carboxyphenyl)amino]-1,3,5-triazine is in a mass ratio of 1:0.4:0.0025:0.05:0.2.

[0045] The specific preparation process of the triazine cyclomodified polyurethane prepolymer in Example 1c is as follows:

[0046] S-1. Under nitrogen protection, dry poly(neopentyl adipate)-1,6-hexanediol adipate, dicyclohexylmethane diisocyanate, and dibutyltin dilaurate are mixed and reacted at 85-90℃ for 4 hours. Then, 2,2-dimethylolpropionic acid is added, and the reaction is continued for 1 hour to obtain polyurethane prepolymer I.

[0047] S-2. Add 2,4,6-tris[(p-carboxyphenyl)amino]-1,3,5-triazine to polyurethane prepolymer I, react at 80~85℃ for 2h, and then add triethylamine to neutralize, to obtain siloxane-modified polyurethane prepolymer;

[0048] The mixture contains poly(neopentyl adipate)-1,6-hexanediol ester diol, dicyclohexylmethane diisocyanate, dibutyltin dilaurate, 2,2-dimethylolpropionic acid, and 2,4,6-tris[(p-carboxyphenyl)amino]-1,3,5-triazine in a mass ratio of 1:0.5:0.003:0.04:0.1.

[0049] The specific preparation process of the triazine cyclomodified polyurethane prepolymer in Example 1d is as follows:

[0050] S-1. Under nitrogen protection, dry poly(neopentyl adipate)-1,6-hexanediol adipate, dicyclohexylmethane diisocyanate, and dibutyltin dilaurate are mixed and reacted at 85-90℃ for 3 hours. Then, 2,2-dimethylolpropionic acid is added, and the reaction is continued for 2 hours to obtain polyurethane prepolymer I.

[0051] S-2. Add 2,4,6-tris(4-aminophenyl)-1,3,5-triazine to polyurethane prepolymer I, react at 80~85℃ for 2.5h, then add triethylamine to neutralize, to obtain siloxane-modified polyurethane prepolymer;

[0052] The composition of poly(neopentyl adipate)-1,6-hexanediol ester diol, dicyclohexylmethane diisocyanate, dibutyltin dilaurate, 2,2-dimethylolpropionic acid, and 2,4,6-tris(4-aminophenyl)-1,3,5-triazine is in a mass ratio of 1:0.45:0.002:0.06:0.15.

[0053] Example 2 Preparation of siloxane-modified polyurethane prepolymer

[0054] Example 2a: Specific preparation process of siloxane-modified polyurethane prepolymer:

[0055] s1. Under nitrogen protection, dry polytetrahydrofuran ether diol, isophorone diisocyanate and dibutyltin dilaurate are mixed and reacted at 70~75℃ for 2h. Then 2,2-dimethylolpropionic acid is added and the reaction is continued for 2h to obtain polyurethane prepolymer II.

[0056] s2. Add dry hydroxyl-terminated polydimethylsiloxane to polyurethane prepolymer II, react at 80~85℃ for 2h, add triethylamine to neutralize, and obtain siloxane-modified polyurethane prepolymer.

[0057] The mass ratio of polytetrahydrofuran ether diol, isophorone diisocyanate, dibutyltin dilaurate, 2,2-dimethylolpropionic acid and hydroxyl-terminated polydimethylsiloxane is 1:0.6:0.0025:0.06:0.2.

[0058] Furthermore, the molecular weight of the poly(neopentyl adipate)-1,6-hexanediol ester used above is 1500~2000.

[0059] Example 2 Preparation of siloxane-modified polyurethane prepolymer

[0060] The specific preparation process of the siloxane-modified polyurethane prepolymer in Example 2b:

[0061] 1. Under nitrogen protection, dry polytetrahydrofuran ether diol, isophorone diisocyanate and dibutyltin dilaurate are mixed and reacted at 70~75℃ for 2.5h. Then 2,2-dimethylolpropionic acid is added and the reaction is continued for 2.5h to obtain polyurethane prepolymer II.

[0062] s2. Add dry hydroxyl-terminated polydimethylsiloxane to polyurethane prepolymer II, react at 80~85℃ for 2.5h, add triethylamine to neutralize, and obtain siloxane-modified polyurethane prepolymer;

[0063] The mass ratio of polytetrahydrofuran ether diol, isophorone diisocyanate, dibutyltin dilaurate, 2,2-dimethylolpropionic acid and hydroxyl-terminated polydimethylsiloxane is 1:0.5:0.003:0.08:0.25.

[0064] Example 2 Preparation of siloxane-modified polyurethane prepolymer

[0065] Example 2c: Specific preparation process of siloxane-modified polyurethane prepolymer:

[0066] s1. Under nitrogen protection, dry polytetrahydrofuran ether diol, isophorone diisocyanate and dibutyltin dilaurate are mixed and reacted at 70~75℃ for 3h. Then 2,2-dimethylolpropionic acid is added and the reaction is continued for 3h to obtain polyurethane prepolymer II.

[0067] s2. Add dry hydroxyl-terminated polydimethylsiloxane to polyurethane prepolymer II, react at 80~85℃ for 3h, add triethylamine to neutralize, and obtain siloxane-modified polyurethane prepolymer.

[0068] The mass ratio of polytetrahydrofuran ether diol, isophorone diisocyanate, dibutyltin dilaurate, 2,2-dimethylolpropionic acid and hydroxyl-terminated polydimethylsiloxane is 1:0.55:0.002:0.07:0.3.

[0069] Furthermore, the molecular weight of the polytetrahydrofuran ether diol used above is 1000~1500.

[0070] Example 3 Preparation of modified fumed silica

[0071] Preparation process of modified fumed silica: First, virgin fumed silica with a particle size of 15~25nm is activated by plasma treatment, then dispersed in an ethanol solution containing 2wt% silane coupling agent, wherein the mass ratio of fumed silica to silane coupling agent is 3:2, then heated to 65℃ and stirred for 2~3h, and dried to obtain modified fumed silica.

[0072] Example 4: Preparation of carboxylated multi-walled carbon nanotubes

[0073] Preparation process of carboxylated multi-walled carbon nanotubes: Multi-walled carbon nanotubes with a particle size of 10-30 nm and a length of 10-15 μm are added to concentrated sulfuric acid at a temperature of 30-35 °C under stirring. First, potassium nitrate is added as an activator for activation for 10-20 min, and then potassium permanganate is added as an oxidant. The mixture is ultrasonically stirred at a power of 350-400 W for 2-3 h. The mixture is then washed with water until pH 7 and dried. The mass ratio of concentrated sulfuric acid, multi-walled carbon nanotubes, potassium nitrate, and potassium permanganate is 200:4:4:5 to obtain carboxylated multi-walled carbon nanotubes.

[0074] Example 5

[0075] A UV coating composition and a method for preparing the UV coating are as follows:

[0076] The UV coating composition, by weight, comprises: 55 parts of triazine cyclomodified polyurethane prepolymer prepared in Example 1a, 30 parts of siloxane-modified polyurethane prepolymer prepared in Example 2c, 2.5 parts of composite modified filler, 15 parts of tricyclodecyl dimethyl diacrylate, 42 parts of ethyl acetate, 3 parts of 2-hydroxy-2-methyl-1-phenyl-1-propanone, 0.6 parts of antioxidant 1010, 0.4 parts of antioxidant 168, 0.2 parts of silicone defoamer BYK-306, and 0.3 parts of polyester-modified polydimethylsiloxane leveling agent KMT-5504;

[0077] The composite modified filler is composed of 2.5 parts by weight of the modified fumed silica prepared in Example 3 and 2.5 parts by weight of the carboxylated multi-walled carbon nanotubes prepared in Example 4.

[0078] UV coating preparation method: Triazine cyclomodified polyurethane prepolymer, siloxane-modified polyurethane prepolymer and organic solvent are heated and mixed to form an emulsion, and then composite modified filler, reactive diluent, photoinitiator, antioxidant, defoamer and leveling agent are added and dispersed at high speed to obtain high temperature resistant UV coating.

[0079] Example 6

[0080] A UV coating composition and a method for preparing the UV coating are as follows:

[0081] The UV coating composition comprises, by weight, 60 parts of the triazine cyclomodified polyurethane prepolymer prepared in Example 1b, 35 parts of the siloxane-modified polyurethane prepolymer prepared in Example 2b, 4.5 parts of the composite modified filler, 18 parts of pentaerythritol triacrylate, 48 parts of ethyl acetate, 4 parts of 2,2-dimethoxy-2-phenylacetophenone, 0.9 parts of antioxidant 1010, 0.6 parts of antioxidant 168, 0.4 parts of silicone defoamer BYK-306, and 0.5 parts of polyester-modified polydimethylsiloxane leveling agent KMT-5504;

[0082] The composite modified filler is composed of 2.5 parts by weight of the modified fumed silica prepared in Example 3 and 2 parts by weight of the carboxylated multi-walled carbon nanotubes prepared in Example 4.

[0083] UV coating preparation method: Triazine cyclomodified polyurethane prepolymer, siloxane-modified polyurethane prepolymer and organic solvent are heated and mixed to form an emulsion, and then composite modified filler, reactive diluent, photoinitiator, antioxidant, defoamer and leveling agent are added and dispersed at high speed to obtain high temperature resistant UV coating.

[0084] Example 7

[0085] A UV coating composition and a method for preparing the UV coating are as follows:

[0086] The UV coating composition comprises, by weight, 65 parts of the triazine cyclomodified polyurethane prepolymer prepared in Example 1c, 25 parts of the siloxane-modified polyurethane prepolymer prepared in Example 2a, 6 parts of the composite modified filler, 20 parts of trimethylolpropane triacrylate, 45 parts of ethyl acetate, 5 parts of 2,4,6-trimethylbenzophenone, 1.2 parts of antioxidant 1010, 0.8 parts of antioxidant 168, 0.5 parts of silicone defoamer BYK-306, and 0.2 parts of polyester-modified polydimethylsiloxane leveling agent KMT-5504;

[0087] The composite modified filler is composed of 3.6 parts by weight of the modified fumed silica prepared in Example 3 and 2.4 parts by weight of the carboxylated multi-walled carbon nanotubes prepared in Example 4.

[0088] UV coating preparation method: Triazine cyclomodified polyurethane prepolymer, siloxane-modified polyurethane prepolymer and organic solvent are heated and mixed to form an emulsion, and then composite modified filler, reactive diluent, photoinitiator, antioxidant, defoamer and leveling agent are added and dispersed at high speed to obtain high temperature resistant UV coating.

[0089] Example 8

[0090] A UV coating composition and a method for preparing the UV coating are as follows:

[0091] The UV coating composition, by weight, consists of: 58 parts of triazine cyclomodified polyurethane prepolymer prepared in Example 1a, 30 parts of siloxane-modified polyurethane prepolymer prepared in Example 2b, 7 parts of composite modified filler, 17 parts of tripropylene glycol diacrylate, 40 parts of ethyl acetate, 4 parts of 1-hydroxycyclohexylphenyl ketone, 0.8 parts of antioxidant 1010, 0.6 parts of antioxidant 168, 0.4 parts of silicone defoamer BYK-306, and 0.3 parts of polyester-modified polydimethylsiloxane leveling agent KMT-5504.

[0092] The composite modified filler is composed of 4 parts by weight of the modified fumed silica prepared in Example 3 and 3 parts by weight of the carboxylated multi-walled carbon nanotubes prepared in Example 4.

[0093] UV coating preparation method: Triazine cyclomodified polyurethane prepolymer, siloxane-modified polyurethane prepolymer and organic solvent are heated and mixed to form an emulsion, and then composite modified filler, reactive diluent, photoinitiator, antioxidant, defoamer and leveling agent are added and dispersed at high speed to obtain high temperature resistant UV coating.

[0094] Example 9

[0095] A UV coating composition and a method for preparing the UV coating are as follows:

[0096] The UV coating composition, by weight, comprises: 63 parts of the triazine cyclomodified polyurethane prepolymer prepared in Example 1c, 33 parts of the siloxane-modified polyurethane prepolymer prepared in Example 2c, 4 parts of the composite modified filler, 16 parts of tricyclodecyl dimethyl diacrylate, 40 parts of ethyl acetate, 3.5 parts of 2-hydroxy-2-methyl-1-phenyl-1-propanone, 0.8 parts of antioxidant 1010, 0.6 parts of antioxidant 168, 0.3 parts of silicone defoamer BYK-306, and 0.3 parts of polyester-modified polydimethylsiloxane leveling agent KMT-5504;

[0097] The composite modified filler is composed of 2 parts by weight of the modified fumed silica prepared in Example 3 and 2 parts by weight of the carboxylated multi-walled carbon nanotubes prepared in Example 4.

[0098] UV coating preparation method: Triazine cyclomodified polyurethane prepolymer, siloxane-modified polyurethane prepolymer and organic solvent are heated and mixed to form an emulsion, and then composite modified filler, reactive diluent, photoinitiator, antioxidant, defoamer and leveling agent are added and dispersed at high speed to obtain high temperature resistant UV coating.

[0099] Example 10

[0100] A UV coating composition and a method for preparing a UV coating, which differ from Example 5 in that: the triazine cyclomodified polyurethane prepolymer is the triazine cyclomodified polyurethane prepolymer prepared in Example 1d.

[0101] Comparative Example 1

[0102] A high-temperature resistant UV coating composition and its preparation method differ from Example 5 in that: the triazine cyclomodified polyurethane prepolymer prepared in Example 1a is 85 parts, and the siloxane-modified polyurethane prepolymer prepared in Example 2c is 0 parts.

[0103] Comparative Example 2

[0104] A high-temperature resistant UV coating composition and its preparation method differ from Example 5 in that: the triazine cyclomodified polyurethane prepolymer prepared in Example 1a is 0 parts, and the siloxane-modified polyurethane prepolymer prepared in Example 2c is 85 parts.

[0105] Comparative Example 3

[0106] A high-temperature resistant UV coating composition and its preparation method differ from Example 5 in that: a triazine cyclomodified polyurethane prepolymer is used, and diphenylmethane diisocyanate is used instead of dicyclohexylmethane diisocyanate in the preparation.

[0107] Comparative Example 4

[0108] A UV coating composition and preparation method differ from Example 5 in that: a siloxane-modified polyurethane prepolymer is used, and diphenylmethane diisocyanate is used instead of isophorone diisocyanate in the preparation.

[0109] Comparative Example 5

[0110] A UV coating composition and preparation method differ from Example 10 in that: a siloxane-modified polyurethane prepolymer is used, and 2,4-toluene diisocyanate is used instead of dicyclohexylmethane diisocyanate in the preparation.

[0111] Comparative Example 6

[0112] A UV coating composition and preparation method differ from Example 5 in that: a siloxane-modified polyurethane prepolymer is used, and hydroxyethyl acrylate is used instead of 2,4,6-tris[(p-carboxyphenyl)amino]-1,3,5-triazine in the preparation.

[0113] Comparative Example 7

[0114] A UV coating composition and preparation method, which differs from Example 5 in that: 0 parts of composite modified filler are included.

[0115] Comparative Example 8

[0116] A UV coating composition and preparation method, which differs from Example 5 in that: a composite filler is used instead of a composite modified filler;

[0117] The composite filler is composed of 2 parts by weight of fumed silica with a primary particle size of 15-25 nm and 2 parts by weight of multi-walled carbon nanotubes with a particle size of 10-30 nm and a length of 10-15 μm.

[0118] Comparative Example 9

[0119] A UV coating composition and preparation method differ from Example 6 in that the modified fumed silica prepared in Example 3 replaces the composite modified filler, and the modified fumed silica prepared in Example 3 is 4.5 parts.

[0120] Comparative Example 10

[0121] A UV coating composition and preparation method differ from Example 6 in that: the carboxylated multi-walled carbon nanotubes prepared in Example 4 replace the composite modified filler, and the amount of carboxylated multi-walled carbon nanotubes prepared in Example 4 is 4.5 parts.

[0122] Effect Example

[0123] The UV coatings prepared from the UV coating compositions of Examples 5-10 and Comparative Examples 1-9 were sprayed onto PI workpieces with aluminum plating. Leveling was performed for 2-3 minutes, resulting in a coating thickness of 15-20 μm. After leveling, the coating was heated to 55-75°C and cured using UV light. The coatings were then subjected to performance testing, and the results are shown in the table below.

[0124] Adhesion was tested according to GB / T 9286-2021 "Cross-cut test for paints and varnishes"; heat resistance was tested according to GB / T 1735-2009 "Determination of heat resistance of paints and varnishes" (placed in an oven at 180℃ for 12 hours); thermal cycling test: cold and hot cycling was performed from -40℃ to 180℃, each cycle was held for 90 minutes, and 1500 cycles were performed; yellowing resistance was tested according to GB / T 23987-2009 "Artificial weathering of paint and varnish coatings exposed to fluorescent ultraviolet light and water" (cycle cycle is 102 minutes of ultraviolet irradiation (temperature 45±3℃) / 18 minutes of water spraying and wetting (condensation temperature 55±3℃, humidity >90% during condensation stage), cycle 720 hours).

[0125] Table UV coating performance

[0126]

[0127] As can be seen from the table above, compared with Comparative Examples 1 to 10, the UV coating composition of the present invention includes: a triazine cyclomodified polyurethane prepolymer prepared by polypentyl adipate-1,6-hexanediol ester diol, dicyclohexylmethane diisocyanate, dibutyltin dilaurate, 2,2-dimethylolpropionic acid, and a triazine cyclomodifier; a siloxane-modified polyurethane prepolymer prepared by the siloxane-modified polyurethane prepolymer by polytetrahydrofuran ether diol, isophorone diisocyanate, dibutyltin dilaurate, 2,2-dimethylolpropionic acid, and hydroxyl-terminated polydimethylsiloxane; a composite modified filler composed of modified fumed silica and carboxylated multi-walled carbon nanotubes; and a composition system combining reactive diluent, photoinitiator, defoamer, and leveling agent. The UV coating prepared by this composition has more stable heat resistance and thermal cycling properties, excellent high-temperature resistance and long-term high-temperature resistance, and also excellent resistance to yellowing.

[0128] In summary, the UV coating prepared by the high-temperature resistant UV coating composition of the present invention has excellent long-term temperature resistance and can meet the requirements of extreme high-temperature scenarios.

[0129] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit and essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within the present invention.

[0130] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A high-temperature UV-resistant coating composition, characterized in that, The raw materials consist of the following parts by weight: 55-65 parts of triazine cyclomodified polyurethane prepolymer, 25-35 parts of siloxane-modified polyurethane prepolymer, 2.5-7 parts of composite modified filler, 15-20 parts of reactive diluent, 35-50 parts of organic solvent, 3-5 parts of photoinitiator, 1-2 parts of antioxidant, 0.2-0.5 parts of defoamer, and 0.2-0.5 parts of leveling agent; The composite modified filler is composed of a mixture of modified fumed silica and carboxylated multi-walled carbon nanotubes; The triazine cyclomodified polyurethane prepolymer was prepared by poly(neopentyl adipate-1,6-hexanediol adipate), dicyclohexylmethane diisocyanate, dibutyltin dilaurate, 2,2-dimethylolpropionic acid, and a triazine cyclomodifier. The triazine cyclomodifier is one of 2,4,6-tris[(p-carboxyphenyl)amino]-1,3,5-triazine or 2,4,6-tris(4-aminophenyl)-1,3,5-triazine; The siloxane-modified polyurethane prepolymer was prepared by polytetrahydrofuran ether diol, isophorone diisocyanate, dibutyltin dilaurate, 2,2-dimethylolpropionic acid, and hydroxyl-terminated polydimethylsiloxane. The modified fumed silica is obtained by first activating fumed silica with plasma and then treating it with a coupling agent.

2. The high-temperature UV resistant coating composition according to claim 1, characterized in that, The mass ratio of the poly(neopentyl adipate)-1,6-hexanediol ester diol, dicyclohexylmethane diisocyanate, dibutyltin dilaurate, 2,2-dimethylolpropionic acid, and triazine cyclomodifier is 1:0.4~0.5:0.002~0.003:0.04~0.06:0.1~0.

2.

3. The high-temperature UV resistant coating composition according to claim 1, characterized in that, The mass ratio of polytetrahydrofuran ether diol, isophorone diisocyanate, dibutyltin dilaurate, 2,2-dimethylolpropionic acid and hydroxyl-terminated polydimethylsiloxane is 1:0.5~0.6:0.002~0.003:0.06~0.08:0.2~0.

3.

4. The high-temperature UV resistant coating composition according to claim 1, characterized in that, The composite modified filler is composed of modified fumed silica and carboxylated multi-walled carbon nanotubes in a mass ratio of 2~3:

2.

5. The high-temperature UV-resistant coating composition according to claim 1, characterized in that, The mass ratio of the fumed silica to the silane coupling agent is 3:2; the original particle size of the fumed silica is 15~25nm.

6. A high-temperature UV-resistant coating composition according to claim 1 or 4, characterized in that, The carboxylated multi-walled carbon nanotubes are obtained by treating multi-walled carbon nanotubes with concentrated sulfuric acid, an activator, and an oxidant; wherein the activator is potassium nitrate, and the mass ratio of concentrated sulfuric acid, multi-walled carbon nanotubes, potassium nitrate, and potassium permanganate is 200:4:4:5; the particle size of the multi-walled carbon nanotubes is 10~30nm, and the length is 10~15μm.

7. The high-temperature UV resistant coating composition according to claim 1, characterized in that, The active diluent is one or more of tricyclodecyl dimethyl diacrylate, pentaerythritol triacrylate, trimethylolpropane triacrylate, or tripropylene glycol diacrylate.

8. The high-temperature UV resistant coating composition according to claim 1, characterized in that, The photoinitiator is one or more of 2-hydroxy-2-methyl-1-phenyl-1-propanone, 1-hydroxycyclohexylphenyl ketone, 2,2-dimethoxy-2-phenylacetophenone, and 2,4,6-trimethylbenzophenone.

9. A method for preparing a UV coating from the high-temperature resistant UV coating composition of claim 1, characterized in that, Includes the following steps: Triazine cyclomodified polyurethane prepolymer, siloxane-modified polyurethane prepolymer and organic solvent are heated and mixed to form an emulsion. Then, composite modified filler, reactive diluent, photoinitiator, antioxidant, defoamer and leveling agent are added and dispersed at high speed to obtain a high temperature resistant UV coating.

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