Flame-retardant uv-oxygen dual-curing polyurethane acrylate three-protection paint

Abstract

The application provides a fire-retardant UV-oxygen dual-curing polyurethane acrylate three-protection paint. A preparation method of a polyurethane acrylate prepolymer as a base resin of the paint is as follows: a phosphorus-containing polyol compound is prepared by reacting a hypophosphorous acid compound with a glycidyl ether compound; a monohydric alcohol compound with an oxidizing crosslinking characteristic group is prepared by reacting an unsaturated vegetable oil fatty acid with a polyol; and then the two are reacted with a diisocyanate monomer, a polyol compound and a hydroxyl acrylate monomer to obtain the polyurethane acrylate prepolymer. The three-protection paint prepared from the prepolymer has the characteristics of UV and oxygen dual curing, excellent fire-retardant performance, high flash point, low viscosity and convenient construction. The paint film has high salt mist resistance, high wet heat resistance, high acid and alkali resistance and excellent insulation performance, and can be widely applied in the fields of automobiles, electronics, industrial control, communication, household appliances and military industry.

Description

TECHNICAL FIELD

[0001] The present application relates to a kind of electronic industry circuit board three-proof paint, especially to a kind of flame-retardant UV-oxygen dual-curing polyurethane acrylate three-proof paint. BACKGROUND

[0002] Three-proof paint is a special formula of paint, used to protect circuit board and its related equipment from the erosion of environment, with good high and low temperature resistance;It forms a layer of transparent protective film after curing, with superior insulation, waterproof, moisture-proof, anti-creeping, shockproof, dustproof, anticorrosive, anti-aging, corona-resistant and other properties.The three-proof paint used at present is mainly solvent type three-proof paint.The main problems of solvent type three-proof paint are: heavy odor, affecting working environment and reducing work efficiency;Long-term contact may induce occupational diseases;It will pollute the environment and face policy pressure;Flammable and explosive, with great safety hazards.

[0003] In the era of social environmental protection, people's environmental protection requirements for three-proof paint are getting higher and higher, and three-proof paint is developing towards environmental protection.UV-curable three-proof paint is an environmentally friendly solvent-free coating material, which relies on ultraviolet light to initiate the rapid polymerization and crosslinking of chemically active liquid materials, and instantly cures into film, with the characteristics of "Efficient high efficiency, Enabling wide adaptability, Economical economy, Energy Saving energy saving and Environmental Friendly environmental friendliness", i.e."5E" characteristics, with superior comprehensive performance, and has wide application prospect.However, ultraviolet light is the necessary condition for UV curing, when the ultraviolet light is blocked and cannot penetrate the three-proof paint, these three-proof paints will remain unreacted and uncured state, causing the phenomenon of un-dried shadow area of circuit board, at the same time, unreacted and uncured wet three-proof paint may migrate to adjacent cured area, thus weakening the performance of cured area three-proof paint over time, increasing the reliability risk of circuit board.

[0004] Based on this, UV-humidity dual-curing three-proofing paint has appeared in the market. This kind of three-proofing paint contains a certain amount of isocyanate (-NCO), which can react with moisture in the air to achieve curing in the shadow area. UV-humidity dual-curing three-proofing paint can be UV-cured and humidity-cured, so it can be UV-cured where the ultraviolet light shines, and it can be humidity-cured after UV-curing. In addition, it is solvent-free, which is more environmentally friendly and has superior performance compared to traditional solvent-based three-proofing paint. Chinese patent CN 111500181 A discloses a preparation method of UV-humidity dual-curing acid and alkali resistant three-proofing paint. The UV-humidity dual-curing acid and alkali resistant three-proofing paint prepared by this patent not only avoids the problem that pure UV-curing three-proofing paint cannot achieve complete curing in the shadow area, but also improves the acid and alkali resistance of three-proofing paint, making the protective performance more reliable. However, there are still some problems: isocyanate is extremely easy to react with moisture, even a very small amount of moisture can easily cause the viscosity of three-proofing paint to rise and the storage period to be shortened; frequent opening of the cover makes it easier to contact moisture, which can accelerate the deterioration of the product and make the product extremely unstable. Chinese patent CN109321125 A discloses a UV-humidity dual-curing three-proofing paint. The UV-humidity dual-curing three-proofing paint of this patent improves the storage period of the product by adding a water removal agent. However, too much water removal agent can affect the performance of three-proofing paint, and some can produce gas, causing three-proofing paint to blister after curing.

[0005] With the increasing demand of the market and the increasingly fierce competition, many companies have begun to try flame-retardant UV three-proofing technology. However, the flame-retardant UV three-proofing technology on the market is not mature, and there are almost no flame-retardant three-proofing paints that can meet high requirements. Some flame-retardant three-proofing paints have reached high flame-retardant levels but have poor stability, which can even affect their performance. Chinese patent CN104804626 A discloses a flame-retardant three-proofing paint. The selected flame retardant is an additive type flame retardant such as triphosphate and methyl phosphonate dimethyl. It does not participate in the reaction during photocuring, affecting the adhesion of the flame-retardant three-proofing paint. In addition, with the passage of time, the additive type flame retardant will migrate to the surface of the paint film, causing the paint film to gradually lose its flame-retardant properties. Chinese patent CN 111548726 A discloses a MOP flame retardant and a flame-retardant UV-humidity dual-curing three-proofing paint, as well as its preparation method and application. The MOP flame retardant is obtained by non-halogenated phosphorus polyol and isocyanate acrylate end-capping reaction. The MOP flame retardant is still an additive type flame retardant, but its compatibility with the base resin has been improved through modification. In addition, the patent also improves the storage stability of the product by adding a water removal agent, but the stability problem has not been fundamentally solved. SUMMARY

[0006] In order to solve the technical problem that the pure UV curing type three-proof paint cannot be cured in the shadow area of the circuit board, to solve the storage stability problem of the UV-humidity dual curing three-proof paint, and to solve the migration of the added flame retardant and the poor compatibility with the base resin, the present application relates to a flame-retardant UV-oxygen dual curing polyurethane acrylate three-proof paint which can be cured by oxidative crosslinking under the action of oxygen in the shadow area of the circuit board. The UV-oxygen dual curing polyurethane acrylate prepolymer is a prepolymer which contains both acrylate groups and groups with oxidative crosslinking characteristics and is prepared by first polymerizing a polyol compound with a diisocyanate monomer, and then co-sealing with a monohydric alcohol compound having groups with oxidative crosslinking characteristics and a hydroxyl acrylate. Since the NCO groups in the prepolymer almost completely participate in the reaction, the prepolymer does not contain residual NCO groups and cannot be cured by humidity; the acrylate groups in the prepolymer provide crosslinking sites for radical polymerization initiated by UV curing, and the groups with oxidative crosslinking characteristics provide crosslinking sites for oxidative crosslinking reactions in the presence of oxygen. The coating film contains a large number of urethane bonds, and due to the effect of hydrogen bonds, the coating film has excellent adhesion, wear resistance, oil resistance, acid and alkali resistance, and impact resistance; the unsaturated aliphatic groups with oxidative crosslinking characteristics have hydrophobic and insulating properties and flexibility, so that the paint film has good electrical insulation performance, and at the same time, the deficiencies of pure UV curing type three-proof paint in adhesion and flexibility are compensated.

[0007] In the present application, the flame-retardant hypophosphorous acid compound is synthesized into the UV-oxygen dual curing polyurethane acrylate resin by chemical grafting, so that the resin has flame-retardant properties. There is no report on the preparation of the flame-retardant UV-oxygen dual curing polyurethane acrylate three-proof paint using the UV-oxygen dual curing polyurethane acrylate prepolymer containing phosphorus components.

[0008] Based on this, the present application aims to prepare the flame-retardant UV-oxygen dual curing polyurethane acrylate three-proof paint by using the flame-retardant UV-oxygen dual curing polyurethane acrylate prepolymer as the base material, using the low odor and low irritation active diluent, and using the photoinitiator and the like.

[0009] The flame-retardant UV-oxygen dual curing polyurethane acrylate three-proof paint of the present application contains the following components in the polyurethane acrylate prepolymer as the base resin, by weight percentage:

[0010] (1) at least one polyurethane acrylate prepolymer containing allyl groups at both ends, accounting for 10% to 20% by weight percentage, specifically as the structure of general formula (I):

[0011] A-D-P-D-A (I)

[0012] In the formula, A represents a polyisocyanate, D represents a polyol, and P represents an acrylate group.

[0013] (a) D is a diisocyanate monomer;

[0014] (b) P is a polyol compound;

[0015] (c) A is a hydroxyl acrylate monomer;

[0016] (2) at least one polyurethane acrylate prepolymer of a phosphorus-containing polyol compound having allyl groups at both ends, accounting for 15% to 25% of the weight percentage, specifically as the structure of general formula (II):

[0017] A-D-B-D-A (II)

[0018] wherein:

[0019] (a) D is a diisocyanate monomer;

[0020] (b) B is a phosphorus-containing polyol compound;

[0021] (c) A is a hydroxyl acrylate monomer;

[0022] (3) at least one polyurethane acrylate prepolymer of a monohydric alcohol compound having an oxidatively crosslinkable group at one end and an allyl group at one end, accounting for 10% to 20% of the weight percentage, specifically as the structure of general formula (III):

[0023] L-D-P-D-A (III)

[0024] wherein:

[0025] (a) D is a diisocyanate monomer;

[0026] (b) P is a polyol compound;

[0027] (c) A is a hydroxyl acrylate monomer;

[0028] (d) L is a monohydric alcohol compound having an oxidatively crosslinkable group;

[0029] (4) at least one polyurethane acrylate prepolymer of a phosphorus-containing polyol compound having an oxidatively crosslinkable group at one end and an allyl group at one end, accounting for 15% to 25% of the weight percentage, specifically as the structure of general formula (IV):

[0030] L-D-B-D-A (IV)

[0031] wherein:

[0032] (a) D is a diisocyanate monomer;

[0033] (b) B is a phosphorus-containing polyol compound;

[0034] (c) A is a hydroxyl acrylate monomer;

[0035] (d) L is a monohydric alcohol compound having an oxidatively crosslinkable group;

[0036] (5) at least one polyurethane acrylate prepolymer having phosphorus-containing polyol compounds with oxidatively crosslinkable groups at both ends, accounting for 10% to 20% of the weight percentage, specifically as the structure of general formula (VI):

[0037] L-D-B-D-L (VI)

[0038] Wherein:

[0039] (a) D is a diisocyanate monomer;

[0040] (b) B is a phosphorus-containing polyol compound;

[0041] (c) L is a monohydric alcohol compound having an oxidatively crosslinkable group;

[0042] (6) at least one polyurethane acrylate prepolymer having phosphorus-containing polyol compounds with oxidatively crosslinkable groups at both ends, accounting for 10% to 20% of the weight percentage, specifically as the structure of general formula (VI):

[0043] L-D-B-D-L (VI)

[0044] Wherein:

[0045] (a) D is a diisocyanate monomer;

[0046] (b) B is a phosphorus-containing polyol compound;

[0047] (c) L is a monohydric alcohol compound having an oxidatively crosslinkable group.

[0048] The synthesis process of the polyurethane acrylate prepolymer is as follows:

[0049] (1) The diisocyanate monomer is put into the reaction kettle, and gradually heated to 80-90°C under stirring;

[0050] (2) The phosphorus-containing polyol compound and catalyst are put into the high tank and stirred uniformly, and gradually added to the reaction kettle, and the dropping is completed within 30-60 minutes; after the dropping is completed, keep warm for 1 hour;

[0051] (3) The polyol compound is put into the high tank, and gradually added to the reaction kettle, and the dropping is completed within 30-60 minutes; after the dropping is completed, keep warm for 1 hour;

[0052] (4) The monohydric alcohol compound having an oxidatively crosslinkable group is put into the high tank, and gradually added to the reaction kettle, and the dropping is completed within 30-60 minutes; after the dropping is completed, keep warm for 1 hour;

[0053] (5) cooling to 60~70℃, the reaction kettle into the polymerization inhibitor, the hydroxy acrylate monomer into the high tank, gradually to the reaction kettle dropwise, 30~60 minutes dropwise; after the completion of the drop, heat reaction 2~3 hours, until the NCO residual amount is zero, to obtain polyurethane acrylate prepolymer.

[0054] The diisocyanate monomer is selected from one or more of hexamethylene diisocyanate (HDI), isophorone diisocyanate (IPDI), toluene diisocyanate (TDI), diphenyl methane diisocyanate (MDI) and dicyclohexyl methane diisocyanate (HMDI).

[0055] The polyol compound is selected from one or more of castor oil, castor oil derivatives, polyoxypropylene glycol, polyoxypropylene-ethylene glycol, polyoxypropylene triol, poly (ε-caprolactone) glycol, polytetrahydrofuran glycol, poly (hexanedioate) glycol, poly (neopentyl glycol adipate) glycol, poly (diethylene glycol adipate) glycol, poly (ethylene glycol propylene glycol adipate) glycol and polycarbonate glycol.

[0056] The hydroxy acrylate monomer is selected from one or more of hydroxypropyl acrylate and hydroxyethyl acrylate.

[0057] The phosphorus-containing polyol compound comprises the following components in percentage by weight:

[0058] (1) at least one hypophosphorous acid compound, accounting for 60%~75% of the weight percentage;

[0059] (2) at least one glycidyl ether compound, accounting for 25%~40% of the weight percentage;

[0060] (3) at least one catalyst, accounting for 0.01%~0.3% of the weight percentage;

[0061] The synthesis process of the phosphorus-containing polyol compound is as follows: the hypophosphorous acid compound is put into the reaction kettle, and gradually heated to 140~160℃, and after the material is melted, the stirring is started; the glycidyl ether compound and the catalyst are put into the high tank and mixed uniformly, and gradually dropped into the reaction kettle; dropwise for 30~60 minutes, and then heat at 140~160℃ for 10~12 hours to obtain the phosphorus-containing polyol compound.

[0062] The hypophosphorous acid compound is selected from one or more of 2-carboxyethyl phenyl hypophosphorous acid (CEPPA) and hydroxymethyl phenyl hypophosphorous acid (HMPPA).

[0063] The glycidyl ether compound is selected from one or more of polypropylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, neopentyl glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, 1,2-cyclohexanediol diglycidyl ether, 1,4-butanediol diglycidyl ether, ethylene glycol diglycidyl ether, diethylene glycol diglycidyl ether, dipropylene glycol diglycidyl ether, and versatic acid glycidyl ether.

[0064] The catalyst is selected from triphenylphosphine.

[0065] The monohydric alcohol compound having an oxidatively crosslinkable group comprises, by weight percentage, the following components:

[0066] (1) at least one unsaturated vegetable oil fatty acid, accounting for 75% to 85% by weight percentage;

[0067] (2) at least one polyol, accounting for 10% to 20% by weight percentage;

[0068] (3) at least one refluxing solvent, accounting for 5% to 10% by weight percentage;

[0069] The synthesis process of the monohydric alcohol compound having an oxidatively crosslinkable group is as follows: the unsaturated vegetable oil fatty acid, the polyol, and the refluxing solvent are put into a reaction kettle, stirring is started, and the temperature is gradually increased, and refluxing reaction is carried out at 200 to 220°C until the acid value is less than 5 mgKOH / g, and then the refluxing solvent is removed by vacuum extraction to obtain the monohydric alcohol compound having an oxidatively crosslinkable group.

[0070] The unsaturated vegetable oil fatty acid is selected from one or more of dehydrated castor oil fatty acid, linolenic acid, soybean oil acid, tung oil acid, and tall oil acid.

[0071] The polyol is selected from one or more of glycerol, trimethylolpropane, trimethylolethane, pentaerythritol, and trihydroxyethyl isocyanurate.

[0072] The refluxing solvent is selected from one or more of de-aromatic solvent D30, de-aromatic solvent D40, and xylene.

[0073] The flame-retardant UV-oxygen dual-curing polyurethane acrylate three-protection paint prepared by using the polyurethane acrylate prepolymer as a base material comprises, by weight percentage, the following components:

[0074] (1) at least one polyurethane acrylate prepolymer, accounting for 50% to 60% by weight percentage;

[0075] (2) at least one active diluent, accounting for 35% to 45% by weight percentage;

[0076] (3) at least one photoinitiator, 2% to 5% by weight;

[0077] (4) at least one drier, 0.5% to 3% by weight;

[0078] (5) at least one silane coupling agent, 1% to 4% by weight;

[0079] (6) at least one defoaming agent, 0.1% to 0.5% by weight;

[0080] (7) at least one leveling agent, 0.1% to 0.5% by weight;

[0081] (8) at least one polymerization inhibitor, 0.01% to 0.5% by weight;

[0082] (9) at least one anti-skinning agent, 0.1% to 2% by weight.

[0083] The active diluent is selected from the group consisting of n-hexyl acrylate, cyclohexyl acrylate, isooctyl acrylate, isodecyl acrylate, lauryl acrylate, isobornyl acrylate, acryloyl morpholine, dicyclopentadiene oxyethyl acrylate, tetrahydrofurfuryl acrylate, neopentyl glycol diacrylate, 1,4-butanediol diacrylate, 1,6-hexanediol diacrylate, tripropyleneglycol diacrylate, trimethylolpropane triacrylate, ethoxylated trimethylolpropane triacrylate, propoxylated trimethylolpropane triacrylate, and tris(2-hydroxyethyl)isocyanurate triacrylate.

[0084] The photoinitiator is selected from one or more of benzophenone, 2,2-diethoxyacetophenone, 1-hydroxy-cyclohexyl-phenyl-ketone, benzoin, benzoin ether, benzil ketals, 2,4,6-trimethylbenzoylphenylphosphine oxide, alpha,alpha-dimethyl-alpha-hydroxyacetophenone, 2-hydroxy-2-methyl-1-phenyl-1-propanone, and 4-phenylbenzophenone.

[0085] The drier is selected from one or more of Borchi-Dragon from Borchers, Octa Soligen Cobalt 8 HS, Octa Soligen Zirconium 12 HS, and Octa Soligen Zinc 16 HS.

[0086] The silane coupling agent is selected from one or more of KH540, KH550, KH560, KH570, KH572, KH580, and KH590 from Hangzhou Jessica Chemical Co., Ltd.

[0087] The defoaming agent is selected from one or more of BYK 1790, BYK 1791, BYK 1794 and BYK A535 of BYK-Chemie.

[0088] The leveling agent is selected from one or more of BYK 333, BYK 354, BYK 371, BYK-UV 3505, BYK-UV 3510, BYK-UV 3535 and BYK-UV 3570 of BYK-Chemie.

[0089] The polymerization inhibitor is selected from one or more of hydroquinone, p-tert-butyl hydroquinone and 2,6-di-tert-butyl-p-cresol.

[0090] The anti-skinning agent is selected from one or more of methyl ethyl ketoxime, Ascinin® Anti Skin 0444 (provided by Borchers Company) and Ascinin® Anti Skin 0445 (provided by Borchers Company).

[0091] The features and advantages of the present application are that:

[0092] (1) The flame-retardant UV-oxygen dual-curing polyurethane acrylate three-protection paint of the present application adopts a UV and oxygen dual-curing mechanism. After the three-protection paint is coated on the substrate, the paint film is first cured rapidly by ultraviolet light, which does not affect the subsequent operation of the production line. At the same time, the oxidation crosslinking characteristic groups are oxidized and crosslinked under the action of oxygen, which not only can reinforce the paint film after UV curing, but also can realize the curing of the shadow area, so as to realize the complete curing of the paint film, solve the problem that the pure UV-cured three-protection paint cannot realize the complete curing of the shadow area of the circuit board, and improve the reliability of the paint film protection.

[0093] (2) The flame-retardant UV-oxygen dual-curing polyurethane acrylate three-protection paint of the present application contains a certain amount of flame-retardant material hypophosphorous acid compound, and the paint film has excellent flame-retardant properties, meeting the requirements of American UL certification. The present application first prepares a phosphorus-containing polyol compound by reacting hypophosphorous acid compound with glycidyl ether; then, the phosphorus-containing polyol compound is reacted with diisocyanate monomer, so that the hypophosphorous acid compound is introduced into the polyurethane acrylate prepolymer by chemical grafting, which does not cause the migration of hypophosphorous acid compound, and even does not cause the phase separation phenomenon due to poor miscibility, so as to have good stability, and solve the problems of migration of additive flame retardant and poor compatibility with base resin.

[0094] (3) The flame-retardant UV-oxygen dual-curing polyurethane acrylate three-protection paint contains a certain amount of unsaturated vegetable oil fatty acid, which is a renewable bio-based resource, abundant in source and low in price, and can greatly reduce the dependence on petroleum resources. The unsaturated vegetable oil fatty acid contains unsaturated carbon-carbon double bonds, can absorb oxygen and undergo oxidative crosslinking reaction when exposed to air, thereby increasing the molecular weight of the resin and improving the film performance. At the same time, since the unsaturated vegetable oil fatty acid is a long-chain flexible monomer, the prepared resin has low viscosity and good wetting property to the substrate.

[0095] (4) The flame-retardant UV-oxygen dual-curing polyurethane acrylate three-protection paint of the application selects a suitable active diluent, which has good compatibility with the polyurethane acrylate prepolymer, can effectively reduce the viscosity of the three-protection paint, and make the three-protection paint have low viscosity, easy construction and good leveling property; the active diluent can not only be UV-cured, but also can undergo oxidative crosslinking reaction.

[0096] (5) The flame-retardant UV-oxygen dual-curing polyurethane acrylate three-protection paint does not contain volatile organic solvents or toxic and harmful heavy metal substances, meets the EU ROHS environmental protection requirements, and solves the technical problems of product solvents affecting health and destroying the environment. The flash point is higher than 61℃, and the odor is low. It is a non-hazardous three-protection paint, which can be stored and transported as a conventional chemical.

[0097] (6) The flame-retardant UV-oxygen dual-curing polyurethane acrylate three-protection paint is a single-component package, does not need to be mixed and prepared at the construction site, can be brushed and sprayed, and can be thick film cured. The three-protection paint has high wear resistance, high salt spray resistance, high wet heat resistance, high acid and alkali resistance, and excellent electrical insulation performance, and can be widely used in the fields of automobiles, electronics, industrial control, communication, household appliances and military industry. Embodiment

[0098] The technical solutions in the embodiments of the application will be described below in a clear and complete manner. Obviously, the described embodiments are only part of the embodiments of the application, rather than all the embodiments. Based on the embodiments in the application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the application.

[0099] Embodiment 1

[0100] Preparation of phosphorus-containing polyol compounds A1~A4

[0101] The hypophosphorous acid compound is put into a reaction kettle, gradually heated to 140-160°C, and after the material is melted, the stirring is started; the glycidyl ether compound and the catalyst are put into an elevated tank and mixed uniformly, and gradually added into the reaction kettle; the addition is completed within 30-60 minutes, and then the reaction is kept at 140-160°C for 10-12 hours to obtain the phosphorus-containing polyol compound A1-A4. The synthesis formula of the phosphorus-containing polyol compound is shown in Table 1.

[0102] Table 1 Synthesis formula of the phosphorus-containing polyol compound

[0103] Raw material name A1 A2 A3 A4 Hypophosphorous acid compound 2-carboxyethyl phenyl hypophosphite 71 68 Hydroxymethyl phenyl hypophosphite 66.5 63 Glycidyl ether compound Ethylene glycol diglycidyl ether 28.9 33.4 1,4-Butanediol diglycidyl ether 31.8 36.8 Catalyst Triphenylphosphine 0.1 0.2 0.1 0.2 Total: 100 100 100 100 Example

[0104] Preparation of monohydric alcohol compound B1-B4 having an oxidation crosslinking characteristic group

[0105] The unsaturated vegetable oil fatty acid, the polyol and the refluxing solvent are put into a reaction kettle, the stirring is started, and gradually heated to 200-220°C for refluxing reaction until the acid value is less than 5 mgKOH / g, and then the refluxing solvent is removed by vacuum to obtain the monohydric alcohol compound B1-B4 having an oxidation crosslinking characteristic group. The synthesis formula of the monohydric alcohol compound having an oxidation crosslinking characteristic group is shown in Table 2.

[0106] Table 2 Synthesis formula of the monohydric alcohol compound having an oxidation crosslinking characteristic group

[0107] Raw material name B1 B2 B3 B4 Unsaturated vegetable oil fatty acid Dehydrated castor oil fatty acid 75.8 80.7 Tall oil acid 75.8 80.7 Polyol Trimethylolpropane 18.2 18.2 Glycerin 13.3 13.3 Reflux solvent De-aromatizing solvent D30 6 6 Xylene 6 6 Total: 100 100 100 100 Example

[0108] Preparation of polyurethane acrylate prepolymer

[0109] The specific steps for preparing the polyurethane acrylate prepolymer are as follows:

[0110] (1) The diisocyanate monomer is put into a reaction kettle, and gradually heated to 80-90°C under stirring;

[0111] (2) The phosphorus-containing polyol compound and the catalyst are put into an elevated tank and stirred uniformly, and gradually added into the reaction kettle, and the addition is completed within 30-60 minutes; after the addition is completed, the temperature is kept for 1 hour;

[0112] (3) The polyol compound is put into the elevated tank, and gradually added into the reaction kettle, and the addition is completed within 30-60 minutes; after the addition is completed, the temperature is kept for 1 hour;

[0113] (4) The monohydric alcohol compound having an oxidation crosslinking characteristic group is put into the elevated tank, and gradually added into the reaction kettle, and the addition is completed within 30-60 minutes; after the addition is completed, the temperature is kept for 1 hour;

[0114] (5) The temperature is lowered to 60-70°C, a polymerization inhibitor is added into the reactor, and the hydroxy acrylate monomer is added into the high tank and gradually dropped into the reactor, and the dropping is completed within 30-60 minutes; after the dropping is completed, the reaction is kept for 2-3 hours until the NCO residual amount is zero, and a polyurethane acrylate prepolymer is obtained.

[0115] Table 3 lists four composition examples of the polyurethane acrylate prepolymer. Among them, PUA1 is a polyurethane acrylate prepolymer containing allyl groups at both ends; PUA2 is a polyurethane acrylate prepolymer containing phosphorus-containing polyol compounds containing allyl groups at both ends; PUA3 is a polyurethane acrylate prepolymer containing an oxidation crosslinking characteristic group at one end and an allyl group at one end; PUA4 is a polyurethane acrylate prepolymer containing a phosphorus-containing polyol compound containing an oxidation crosslinking characteristic group at one end and an allyl group at one end; PUA5 is a polyurethane acrylate prepolymer containing an oxidation crosslinking characteristic group at both ends; and PUA6 is a polyurethane acrylate prepolymer containing a phosphorus-containing polyol compound containing an oxidation crosslinking characteristic group at both ends.

[0116] Table 3 Composition examples of polyurethane acrylate prepolymer C1-C4

[0117] Raw material name C1 C2 C3 C4 PUA1 15 13 20 10 PUA2 20 17 15 25 PUA3 15 11 14 20 PUA4 20 25 19 16 PUA5 10 15 13 15 PUA6 20 19 19 14 Total: 100 100 100 100 Example

[0118] Table 4 is a composition example of the flame-retardant UV-oxygen dual-curing polyurethane acrylate three-protection paint D1-D4. According to the formula in Table 4, the various raw materials are accurately weighed, and the self-made polyurethane acrylate prepolymer, active diluent, photoinitiator, drying agent, silane coupling agent, defoamer, leveling agent, polymerization inhibitor and anti-skinning agent are sequentially added into the dispersion kettle, and stirred and dispersed for 0.5-1 hour until uniform, to obtain the flame-retardant UV-oxygen dual-curing polyurethane acrylate three-protection paint D1-D4.

[0119] Table 4 Composition examples of flame-retardant UV-oxygen dual-curing polyurethane acrylate three-protection paint D1-D4

[0120] Raw material name D1 D2 D3 D4 Polyurethane acrylate prepolymer C1 53 C2 56.6 C3 55 C4 51 Active diluent Isobornyl acrylate 20 10 8 15 Lauryl acrylate 4.3 6.7 Acryloyl morpholine 5 10 10.5 Dicyclopentadiene oxyethyl acrylate 15 20 12 15 Photoinitiator 2-Hydroxy-2-methyl-1-phenyl-1-propanone 1 2 1.5 1 1-Hydroxy-cyclohexyl-phenyl ketone 2 1 2 2.5 2,4,6-Trimethylbenzoyl phenylate 0.5 0.5 1 1 Drying catalyst Borchi-Dragon 1 1.2 Octa Soligen Cobalt 8 HS 0.5 0.6 Soligen Zirconium 12 HS 0.5 0.6 Silane coupling agent KH550 2.5 KH560 3 KH572 2 2 Defoamer BYK 1794 0.2 0.2 BYK A535 0.2 0.2 Leveling agent BYK-UV 3505 0.3 0.2 BYK-UV 3535 0.3 0.2 Polymerization inhibitor p-Benzoquinone 0.1 0.1 p-Tert-butyl hydroquinone 0.1 0.1 Anti-skinning agent Methyl ethyl ketoxime 0.1 0.1 Ascinin® Anti Skin 0445 0.3 0.3 Total: 100 100 100 100

[0121] The prepared D1-D4 three-protection paints are respectively sprayed on sample boards using an automatic spraying machine, and then cured under ultraviolet light, and then placed at room temperature for 7 days for performance testing. Table 5 is the performance test results of the flame-retardant UV-oxygen dual-curing polyurethane acrylate three-protection paint corresponding to Table 4. The detection standards and methods are as follows:

[0122] (1) The appearance is tested by visual observation.

[0123] (2) The closed flash point is tested according to GB / T 5208-2008.

[0124] (3) Viscosity is tested according to ASTM D1084.

[0125] (4) Tack-free time is tested according to GB / T 1728-2020.

[0126] (5) Impact strength is tested according to GB 1732-2020.

[0127] (6) Adhesion is tested according to GB 9286-1998.

[0128] (7) Flexibility is tested according to GB / T 1731-2020.

[0129] (8) Pencil hardness is tested according to GB 6739-2022.

[0130] (9) Water resistance is tested according to GB / T 1733-1993.

[0131] (10) Salt water resistance is tested according to GB 1763-1979.

[0132] (11) Sodium hydroxide solution resistance is tested according to GB 1763-1979.

[0133] (12) Sulfuric acid solution resistance is tested according to GB 1763-1979.

[0134] (13) Flame retardancy is tested according to GB / T 5169.16-2017.

[0135] (14) Volume resistivity is tested according to GB / T 1410-2006.

[0136] (15) Salt spray resistance test: 5% NaCl solution is used to continuously spray the sample plate for 168 hours, and the sample plate surface is observed for whitening, blistering, and peeling. If there is no whitening, blistering, and peeling, it is considered that the test “passes”, otherwise it is recorded as “fails”.

[0137] (16) High and low temperature resistance test: the sample plate is treated at -40℃ for 1 hour and then at 80℃ for 1 hour in a constant temperature and humidity chamber, and this treatment process is regarded as one cycle. After 36 cycles, the sample plate surface is observed for whitening, blistering, and peeling. If there is no whitening, blistering, and peeling, it is considered that the test “passes”, otherwise it is recorded as “fails”.

[0138] (17) Double 85 resistance test: the sample plate is placed in a constant temperature and humidity chamber at 85℃ and 85% humidity for 144 hours, and the sample plate surface is observed for whitening, blistering, and peeling. If there is no whitening, blistering, and peeling, it is considered that the test “passes”, otherwise it is recorded as “fails”.

[0139] (18) Viscosity change test: the viscosity of the three-proofing paint was tested after being sealed and stored in dark for 6 months at temperature 23℃ and humidity 25%. The test was considered "pass" if the viscosity change was within 20%, otherwise it was considered "fail".

[0140] Table 5 Performance test results of the flame-retardant UV-oxygen dual-curing polyurethane acrylate three-proofing paint

[0141] Serial number Item D1 D2 D3 D4 1 Appearance Light brown transparent liquid Light brown transparent liquid Light brown transparent liquid Light brown transparent liquid 2 Closed flash point, °C 114 137 141 139 3 Viscosity, mPa.s 121 136 98 85 4 Simple oxidation crosslinking curing skin dry time, h 48 48 48 48 5 Impact strength, cm 50 50 50 50 6 Adhesion, level 0 0 0 0 7 Flexibility, mm 1 1 1 1 8 Pencil hardness 3H 2H 2H 3H 9 Water resistance, h 720 720 720 720 10 Salt water resistance (3% NaCl), h 720 720 720 720 11 Resistance to sodium hydroxide solution (0.1 mol / L), h 480 480 480 480 12 Resistance to sulfuric acid solution (0.05 mol / L), h 480 480 480 480 13 Flame resistance 94-V0 94-V0 94-V0 94-V0 14 Volume resistivity, Ω.cm 1.8 x 10 16 ]]> 2.4 x 10 16 ]]> 1.3 x 10 16 ]]> 3.8 x 10 16 ]] 15 Salt spray resistance test Pass Pass Pass Pass 16 High-low temperature resistance test Pass Pass Pass Pass 17 Double 85 resistance test Pass Pass Pass Pass 18 Viscosity change test Pass Pass Pass Pass

[0142] From the test results in Table 5, it can be concluded that the flame-retardant UV-oxygen dual-curing polyurethane acrylate three-proofing paint of the present application has the following characteristics: (1) high flash point, all the flash points are higher than 100℃; (2) low viscosity, all the viscosities are lower than 150 mPa.s, which is beneficial to the construction; (3) good mechanical properties such as adhesion and flexibility; (4) good chemical resistance such as acid and alkali resistance; (5) excellent flame-retardant property, all reaching 94-V0; (6) good insulation, all the volume resistivities are higher than 1.0 x 10 16 Ω.cm; (7) excellent storage stability; (8) the shadow area can be self-dried by oxidation crosslinking, and the paint film surface is smooth and not sticky after two days; (9) excellent salt spray resistance, high and low temperature resistance and wet heat resistance.

[0143] The above description is only the preferred embodiments of the present application, and is not intended to limit the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A fire-retardant UV-oxygen dual-curable polyurethane acrylate three-antireflection coating, characterized by, As its base resin, the polyurethane acrylate prepolymer comprises the following components by weight percentage: (1) at least one polyurethane acrylate prepolymer containing allyl groups at both ends, accounting for 10% to 20% by weight percentage, specifically as the structure of general formula (I): A-D-P-D-A (I) Wherein: (a) D is a diisocyanate monomer; (b) P is a polyol compound; (c) A is a hydroxy acrylate monomer; (2) at least one polyurethane acrylate prepolymer containing phosphorus-containing polyol compounds containing allyl groups at both ends, accounting for 15% to 25% by weight percentage, specifically as the structure of general formula (II): A-D-B-D-A (II) Wherein: (a) D is a diisocyanate monomer; (b) B is a phosphorus-containing polyol compound; (c) A is a hydroxy acrylate monomer; (3) at least one polyurethane acrylate prepolymer containing allyl groups at one end and containing oxidation crosslinking characteristic groups at one end, accounting for 10% to 20% by weight percentage, specifically as the structure of general formula (III): L-D-P-D-A (III) Wherein: (a) D is a diisocyanate monomer; (b) P is a polyol compound; (c) A is a hydroxy acrylate monomer; (d) L is a monohydric alcohol compound with oxidation crosslinking characteristic groups; (4) at least one polyurethane acrylate prepolymer containing phosphorus-containing polyol compounds containing allyl groups at one end and containing oxidation crosslinking characteristic groups at one end, accounting for 15% to 25% by weight percentage, specifically as the structure of general formula (IV): L-D-B-D-A (IV) Wherein: (a) D is a diisocyanate monomer; (b) B is a phosphorus-containing polyol compound; (c) A is a hydroxy acrylate monomer; (d) L is a monohydric alcohol compound with oxidation crosslinking characteristic groups; (5) at least one polyurethane acrylate prepolymer containing oxidation crosslinking characteristic groups at both ends, accounting for 5% to 15% by weight percentage, specifically as the structure of general formula (V): L-D-P-D-L (V) Wherein: (a) D is a diisocyanate monomer; (b) P is a polyol compound; (c) L is a monohydric alcohol compound with oxidation crosslinking characteristic groups; (6) at least one polyurethane acrylate prepolymer containing phosphorus-containing polyol compounds containing oxidation crosslinking characteristic groups at both ends, accounting for 10% to 20% by weight percentage, specifically as the structure of general formula (VI): L-D-B-D-L (VI) Wherein: (a) D is a diisocyanate monomer; (b) B is a phosphorus-containing polyol compound; (c) L is a monohydric alcohol compound with oxidation crosslinking characteristic groups; The phosphorus-containing polyol compound comprises the following components by weight percentage: at least one hypophosphorous acid compound, accounting for 60% to 71% by weight percentage; at least one glycidyl ether compound, accounting for 25% to 33.4% by weight percentage; at least one catalyst, accounting for 0.01% to 0.3% by weight percentage; The synthesis process of the phosphorus-containing polyol compound is: the hypophosphorous acid compound is put into a reaction kettle, gradually heated to 140-160℃, after the material is melted, the stirring is started; the glycidyl ether compound and the catalyst are put into an elevated tank and uniformly mixed, gradually added into the reaction kettle; the adding is completed within 30-60 minutes, then the reaction is kept at 140-160℃ for 10-12 hours to obtain the phosphorus-containing polyol compound; The hypophosphorous acid compound is selected from one or more of 2-carboxyethyl phenyl hypophosphorous acid (CEPPA) and hydroxymethyl phenyl hypophosphorous acid (HMPPA); the glycidyl ether compound is selected from one or more of polypropylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, neopentyl glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, 1,2-cyclohexanediol diglycidyl ether, 1,4-butanediol diglycidyl ether, ethylene glycol diglycidyl ether, diethylene glycol diglycidyl ether, dipropylene glycol diglycidyl ether and tertiary glycidyl carbonate; and the catalyst is triphenylphosphine; The monohydric alcohol compound with the oxidation crosslinking characteristic group comprises, in percentage by weight, the following components: at least one unsaturated vegetable oil fatty acid, accounting for 75%-85% by weight; at least one polyhydric alcohol, accounting for 10%-20% by weight; and at least one refluxing solvent, accounting for 5%-10% by weight; The synthesis process of the monohydric alcohol compound with the oxidation crosslinking characteristic group is: the unsaturated vegetable oil fatty acid, the polyhydric alcohol and the refluxing solvent are put into a reaction kettle, the stirring is started, and the temperature is gradually increased to 200-220℃ for refluxing reaction until the acid value is less than 5 mgKOH / g, then the refluxing solvent is removed by vacuum to obtain the monohydric alcohol compound with the oxidation crosslinking characteristic group; The unsaturated vegetable oil fatty acid is selected from one or more of dehydrated castor oil fatty acid, linolenic acid, soybean oil acid, tung oil acid and tall oil acid; the polyhydric alcohol is selected from one or more of glycerol, trimethylolpropane, trihydroxymethylethane, pentaerythritol and trihydroxyethyl isocyanurate; and the refluxing solvent is selected from one or more of de-aromatic solvent D30, de-aromatic solvent D40 and xylene. 2.The fire-retardant UV-oxygen dual-curable polyurethane acrylate water-proof paint according to claim 1, characterized in that, The synthesis process of the polyurethane acrylate prepolymer is: (1) the diisocyanate monomer is put into a reaction kettle, and the temperature is gradually increased to 80-90℃ under stirring; (2) the phosphorus-containing polyol compound and the catalyst are put into an elevated tank, uniformly stirred, and gradually added into the reaction kettle, and the adding is completed within 30-60 minutes; after the adding is completed, the temperature is kept for 1 hour; (3) the polyhydric alcohol compound is put into the elevated tank, gradually added into the reaction kettle, and the adding is completed within 30-60 minutes; after the adding is completed, the temperature is kept for 1 hour; (4) the monohydric alcohol compound with the oxidation crosslinking characteristic group is put into the elevated tank, gradually added into the reaction kettle, and the adding is completed within 30-60 minutes; after the adding is completed, the temperature is kept for 1 hour; (5) cooling to 60~70℃, the reaction kettle into the polymerization inhibitor, the hydroxyl acrylate monomer into the high tank, gradually to the reaction kettle drop, 30~60 minutes drop; drop after the completion of the reaction for 2~3 hours, to the NCO residual amount is zero, to obtain polyurethane acrylate prepolymer. 3.The fire-retardant UV-oxygen dual-curable polyurethane acrylate water-proof paint according to claim 1, characterized in that, The diisocyanate monomer is selected from one or more of hexamethylene diisocyanate (HDI), isophorone diisocyanate (IPDI), toluene diisocyanate (TDI), diphenyl methane diisocyanate (MDI) and dicyclohexyl methane diisocyanate (HMDI); the polyol compound is selected from one or more of castor oil, castor oil derivatives, polyoxypropylene glycol, polyoxypropylene-ethylene glycol, polyoxypropylene triol, poly (ε-caprolactone) glycol, polytetrahydrofuran glycol, poly (hexane adipate) glycol, poly (neopentyl glycol adipate) glycol, poly (diethylene glycol adipate) glycol, poly (ethylene propylene glycol adipate) glycol and polycarbonate glycol; the hydroxyl acrylate monomer is selected from one or more of hydroxypropyl acrylate and hydroxyethyl acrylate. 4.The fire-retardant UV-oxygen dual-curable polyurethane acrylate paint according to claim 1, characterized in that, The flame-retardant UV-oxygen dual-curing polyurethane acrylate three-protection paint prepared by using the polyurethane acrylate prepolymer as a base material comprises the following components in percentage by weight: (1) at least one polyurethane acrylate prepolymer, accounting for 50%~60% of the weight percentage; (2) at least one active diluent, accounting for 35%~45% of the weight percentage; (3) at least one photoinitiator, accounting for 2%~5% of the weight percentage; (4) at least one drier, accounting for 0.5%~3% of the weight percentage; (5) at least one silane coupling agent, accounting for 1%~4% of the weight percentage; (6) at least one defoaming agent, accounting for 0.1%~0.5% of the weight percentage; (7) at least one leveling agent, accounting for 0.1%~0.5% of the weight percentage; (8) at least one polymerization inhibitor, accounting for 0.01%~0.5% of the weight percentage; (9) at least one anti-skinning agent, accounting for 0.1%~2% of the weight percentage. 5.The fire-retardant UV-oxygen dual-curable polyurethane acrylate paint according to claim 4, characterized in that, The active diluent is selected from the group consisting of n-hexyl acrylate, cyclohexyl acrylate, isooctyl acrylate, isodecyl acrylate, lauryl acrylate, isobornyl acrylate, acryloyl morpholine, dicyclopentadiene oxyethyl acrylate, tetrahydrofurfuryl acrylate, neopentyl glycol diacrylate, 1,4-butanediol diacrylate, 1,6-hexanediol diacrylate, tripropyleneglycol diacrylate, trimethylolpropane triacrylate, ethoxylated trimethylolpropane triacrylate, propoxylated trimethylolpropane triacrylate, tri(2-hydroxyethyl)isocyanurate triacrylate; the photoinitiator is selected from one or more of benzophenone, 2,2-diethoxyacetophenone, 1-hydroxy-cyclohexyl-phenyl ketone, benzoin, benzoin ether, benzil ketals, 2,4,6-trimethylbenzoyl phenyl phosphine oxide, alpha, alpha-dimethyl-alpha-hydroxyacetophenone, 2-hydroxy-2-methyl-1-phenyl-1-propanone, and 4-phenylbenzophenone; the siccatives are selected from one or more of Borchi-Dragon from Borchers, Octa Soligen Cobalt 8 HS, Octa Soligen Zirconium 12 HS, and Octa Soligen Zinc 16 HS; the silane coupling agents are selected from one or more of KH540, KH550, KH560, KH570, KH572, KH580, and KH590 from Hangzhou Jessica Chemical Co., Ltd.; the defoamers are selected from one or more of BYK 1790, BYK 1791, BYK 1794, and BYK A535 from BYK-Chemie; the leveling agents are selected from one or more of BYK 333, BYK 354, BYK 371, BYK-UV 3505, BYK-UV 3510, BYK-UV 3535, and BYK-UV 3570 from BYK-Chemie; the polymerization inhibitors are selected from one or more of hydroquinone, p-tert-butyl hydroquinone, and 2,6-di-tert-butyl-p-cresol; and the anti-skinning agents are selected from one or more of methyl ethyl ketoxime, Ascinin® Anti Skin 0444, and Ascinin® Anti Skin 0445.