A waterborne uv resin, its preparation method and application

Abstract

The present application relates to a kind of aqueous UV resin and its preparation method and application.Its solid fraction is prepared from the following weight content of components: isocyanate 19-37%, non-polyoxypropylene polyol with functionality of 2-4 46-72%, ionizable group-containing compound 3-6%, low molecular compound containing polyhydroxy and / or amine group 1-7%, hydroxy acrylate 1-4%, hydroxy fluorine-containing polyol 1-14%.The aqueous UV resin of the present application, when applied to water-based wood coatings, the polybutadiene segment imparts excellent flexibility and wear resistance of the paint film of the coating, and the polybutadiene segment can participate in the crosslinking reaction of the resin, achieving the characteristics of hard and tough of the resin paint film;In addition, the fluorine-containing segment greatly reduces the surface energy of the resin paint film, so that the resin sprayed on the wooden substrate has excellent penetration and wettability, ultimately giving the coating excellent appearance, hand feeling and more excellent hardness, toughness, stain resistance and chemical resistance.

Description

Technical Field

[0001] This invention relates to the field of waterborne wood coatings, and more particularly to a waterborne UV resin based on polybutadiene and fluorinated modification, and its application in waterborne UV-cured wood coatings. Background Technology

[0002] Solvent-based coatings are increasingly restricted in their application areas due to their high VOC emissions and significant harm to human health and the environment. Meanwhile, water-based environmentally friendly coatings have achieved successful commercial applications in a growing number of fields.

[0003] However, it is undeniable that although solvent-based coatings are more polluting, their performance in many applications still surpasses that of water-based coatings. Therefore, developing higher-performance water-based coatings is of great significance for further promoting the water-based coating trend. In contrast, water-based UV coatings, with their high efficiency and high performance, have approached or reached the performance levels of solvent-based coatings in many application areas. However, water-based UV coatings often suffer from hardness and brittleness due to their high cross-linking properties, and also exhibit insufficient penetration and moderate stain resistance on some types of wood. Therefore, solving these problems is crucial for expanding the application areas of water-based paints.

[0004] CN107286319A pertains to the field of inks, where different applications and performance concerns exist. The substance and preparation method protected by this patent are low-molecular-weight polyurethane polymers, primarily designed to meet the resolubility requirements of the ink industry. Other properties are developed and maintained based on resolubility. However, such low-molecular-weight substances are unsuitable for wood coatings, leading to problems such as brittleness and poor chemical resistance. The remaining processes are conventional and therefore do not provide inspiration for this invention.

[0005] The main protected content of patent CN105765013A is the solvent-free resin synthesis process, which is a technical process protection; while the process used in this patent is the acetone method, and the two are unrelated, so they do not provide any technical inspiration for this patent.

[0006] Patent CN102977684A is also a patent in the field of inks. Its Example 6 only uses polybutadiene as a polyol (polybutadiene itself is also a conventional raw material). The role of polybutadiene in the resin is completely different from and unrelated to the role ultimately achieved by this patent (mainly because different application fields focus on different and unrelated performance). Therefore, it does not provide any inspiration for this invention. Summary of the Invention

[0007] Therefore, the purpose of this invention is to address the shortcomings of existing waterborne UV wood coatings in terms of film hardness, brittleness, permeability, and stain resistance by providing a waterborne UV resin based on polybutadiene and fluorinated modification. This resin has a hyperbranched structure, in which the introduced polybutadiene segments can participate in the resin crosslinking reaction, greatly improving the resin's flexibility while increasing crosslinking density and maintaining high hardness. Simultaneously, the fluorinated segments effectively improve the coating's penetration and wetting properties on the substrate, reducing surface energy, thereby significantly improving the coating effect on wood substrates and the film's chemical resistance and stain resistance.

[0008] To achieve the above objectives, the present invention provides the following technical solution:

[0009] A waterborne UV resin based on polybutadiene and fluorinated modification, wherein the resin is prepared by reacting components comprising the following weight percentages, based on a total solids content of 100 wt% of all components:

[0010] (a) Isocyanates, 19-37 wt%;

[0011] (b) Non-polyoxypropylene polyols with a functionality of 2-4, 46-72 wt%;

[0012] (c) Compounds containing ionizable groups, 3-6 wt%;

[0013] (d) Low molecular weight compounds containing polyhydroxy and / or amino groups, 1-7 wt%;

[0014] (e) Hydroxy acrylates, 1-4 wt%;

[0015] (f) Hydroxyfluorinated polyols, 1-14 wt%.

[0016] The component (a) of this invention is selected from one or more of diisocyanates and polyisocyanates with NCO greater than 2.

[0017] Preferably, component (a) is selected from one or more of toluene diisocyanate, diphenylmethane diisocyanate, isophorone diisocyanate, hexamethylene diisocyanate and dicyclohexylmethane diisocyanate, and more preferably one or two of isophorone diisocyanate and dicyclohexylmethane diisocyanate.

[0018] The number average molecular weight of component (b) of the present invention is 300 to 8000, preferably 500 to 5000, and more preferably 1000 to 3000.

[0019] Preferably, the non-polyoxypropylene polyol with a functionality of 2 to 4 described in this invention is selected from one or more of polyester polyols, polyether polyols, polymeric polyether polyols, polytetrahydrofuran-type polyols, polycarbonate polyols, polycaprolactone polyols, polyacetal polyols, polyolefin polyols, polyacrylate polyols, and polysiloxane polyols.

[0020] As a preferred embodiment, component (b) is selected from one or more of polyolefin polyols and polyester polyols. For example, the polyolefin polyol may be selected from, but is not limited to, hydroxyl-terminated polybutadiene from Tianyuan Aerospace Materials, and the polyester polyol may be selected from, but is not limited to, polyhexyl adipate from Greenlink Chemicals.

[0021] The component (c) of this invention is selected from one or more of 2,2-dimethylolpropionic acid, dimethylolbutyric acid, dimethylolacetic acid, dihydroxysuccinic acid, and N-(2-aminoethyl)-2-aminoethanesulfonic acid; preferably 2,2-dimethylolpropionic acid.

[0022] The component (d) of this invention is selected from one or more of ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, 3-methylpentane-1,5-pentanediol, 1,6-hexanediol, neopentanediol, 1,4-cyclohexyldiethanol, 1,2-cyclohexanediol, 1,4-cyclohexanediol, 2-ethyl-3-propylpentanediol, 2,2-dimethylpentanediol, diethylene glycol, ethanolamine, N-substituted ethanolamine, glycerol, trimethylolpropane, pentaerythritol, dipentaerythritol, ethylenediamine, and isophorone diamine. Preferably, it is selected from one or more of 1,4-butanediol, dipentaerythritol, and neopentanediol.

[0023] The component (e) of this invention is a compound containing a hydroxyl group and at least one (meth)acrylate group.

[0024] Preferably, the component (e) is selected from pentaerythritol triacrylate, hydroxyethyl methacrylate, hydroxypropyl methacrylate, hydroxybutyl methacrylate, polyoxyethylene mono(meth)acrylate, polyoxypropylene mono(meth)acrylate, or any hydroxylated monomer that has been further reacted with lactone or lactone.

[0025] More preferably, the component (e) is selected from one or more of pentaerythritol triacrylate, hydroxyethyl methacrylate, and hydroxyethyl acrylate.

[0026] The component (f) described in this invention is selected from one or more of the following fluorinated hydroxyl polyols: difluoroethanol, trifluoroethanol, hexafluorobutanol, tridecylfluorooctanol, perfluorooctanol, and perfluorodecanol.

[0027] This invention requires the grafting of fluorinated segments onto resin via reaction. To ensure the grafting rate and stability, low molecular weight fluorinated polyols are required.

[0028] The present invention also provides a method for preparing the aforementioned waterborne UV resin based on polybutadiene and fluorinated modification, comprising the following steps:

[0029] At 45-90℃, component (a) and component (b) and solvent were added to a reactor to prepare a prepolymer of terminal isocyanate. Then, component (c), component (d) and solvent were added to continue the chain extension reaction. After the reaction was completed, component (e) and component (f) and solvent were added to continue the end-capping reaction. After the reaction was completed, a neutralizing agent was added to neutralize the reaction. Then, deionized water was added under high-speed mechanical dispersion to obtain an aqueous UV dispersion containing solvent. The solvent was removed by distillation to obtain an aqueous UV resin emulsion based on polybutadiene and fluorination modification.

[0030] In the method described in this invention, the neutralizing agent includes triethylamine and / or dimethylethanolamine.

[0031] The solvent used in this invention is selected from one or more of acetone, methyl ethyl ketone, tert-butyl methyl ether, tetrahydrofuran, propylene glycol methyl ether, propylene glycol butyl ether, propylene glycol methyl ether acetate, etc., with acetone being preferred.

[0032] The present invention also provides the application of polybutadiene and fluorinated modified waterborne UV resin in waterborne light-curing wood coatings as described above.

[0033] This invention prepares a waterborne UV resin based on polybutadiene and fluorination by combining polybutadiene rubber segments with organofluorocarbon segments. This waterborne UV resin is applicable to both waterborne wood varnishes and paints. In this invention, the preferred macromolecular polybutadiene segments participate in curing and cross-linking, and their excellent flexibility effectively alleviates the hardness and brittleness caused by UV resin curing. When applied to wood coatings, it maintains high film hardness while significantly improving film flexibility, preventing film cracking due to impacts and enhancing protection. Simultaneously, the introduction of low surface energy fluorinated segments effectively overcomes the insufficient permeability of macromolecular chains to the pores of wood substrates, improving the coating's penetration and wetting properties, resulting in more comprehensive protection and a more aesthetically pleasing finish. Furthermore, both polybutadiene and fluorinated segments exhibit good chemical resistance and stain resistance; their synergy ultimately further enhances the coating's performance in application and appearance, enabling the application of waterborne wood coatings in higher-end fields. Detailed Implementation

[0034] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described below with reference to the embodiments. It should be noted that the embodiments do not constitute a limitation on the scope of protection of this invention.

[0035] Preparation of polybutadiene and fluorinated modified waterborne UV resin A:

[0036] 111.2 g of dehydrated isophorone diisocyanate (IPDI), 200 g of hydroxyl-terminated polybutadiene (Mn = 1500), and 135 g of acetone were added to a four-necked round-bottom flask equipped with a nitrogen inlet and outlet. The mixture was stirred at 45-55 °C until the NCO content reached 6.75 wt%. The temperature was raised to 65-75 °C, and 20.2 g of dimethylolpropionate (DMPA), 2.25 g of 1,4-butanediol (BDO), 5.3 g of dipentaerythritol, and 50 g of acetone were added. The reaction was continued with stirring until the NCO content reached 1.55 wt%. Then, 5.42 g of hydroxyethyl methacrylate (HEMA), 20.84 g of perfluorodecaol, and 30 g of acetone were added, and the reaction was continued with stirring until the characteristic NCO peak in the infrared radiation completely disappeared. The mixture was cooled to 40-45℃ and neutralized with 15.2g of triethylamine for about 5 minutes. Then, the mixture was dispersed by adding 548g of water. After dispersion, acetone was separated by distillation to obtain a solvent-free dispersion with a solid content of 35wt%.

[0037] Preparation of polybutadiene and fluorinated modified waterborne UV resin B:

[0038] 111.2 g of dehydrated IPDI, 300 g of hydroxyl-terminated polybutadiene (Mn = 2500), 100 g of polycaprolactone polyol (Mn = 1000), and 140 g of acetone were added to a four-necked round-bottom flask equipped with a nitrogen inlet and outlet. The mixture was stirred at 45-55 °C until the NCO content reached 4.11 wt%. The temperature was raised to 65-75 °C, and 20.2 g of DMPA, 2.6 g of neopentyl glycol NPG, 5.5 g of dipentaerythritol, and 60 g of acetone were added. The reaction was continued with stirring until the NCO content reached 0.97 wt%. Then, 13 g of pentaerythritol triacrylate PETA, 7.6 g of hexafluorobutanol, and 30 g of acetone were added, and the reaction was continued with stirring until the characteristic NCO peak in the infrared radiation completely disappeared. The mixture was cooled to 40-45℃ and neutralized with 15.2g of triethylamine for about 5 minutes. Then, the mixture was dispersed by adding 1040g of water. After dispersion, acetone was separated by distillation to obtain a solvent-free dispersion with a solid content of 35wt%.

[0039] Preparation of polybutadiene and fluorinated modified waterborne UV resin C:

[0040] 66.7 g of dehydrated IPDI, 52.4 g of dicyclohexylmethane diisocyanate (HMDI), 100 g of hydroxyl-terminated polybutadiene (Mn = 1500), 50 g of polycarbonate diol (Mn = 1000), and 100 g of acetone were added to a four-necked round-bottom flask equipped with a nitrogen inlet and outlet. The mixture was stirred at 45-55 °C until the NCO content reached 10.93 wt%. The temperature was raised to 65-75 °C, and 16.8 g of DMPA, 14.4 g of 1,4-cyclohexanediol (CHDM), 6.4 g of dipentaerythritol, and 70 g of acetone were added. The reaction was continued with stirring until the NCO content reached 1.71 wt%. Then, 13 g of PETA, 4.2 g of trifluoroethanol, and 30 g of acetone were added, and the reaction was continued with stirring until the characteristic NCO peak in the infrared radiation completely disappeared. The mixture was cooled to 40-45℃ and neutralized with 12.6g of triethylamine for about 5 minutes. Then, the mixture was dispersed by adding 602g of water. After dispersion, acetone was separated by distillation to obtain a solvent-free dispersion with a solid content of 35wt%.

[0041] Preparation of fluorinated modified waterborne UV resin D:

[0042] 111.2 g of dehydrated isophorone diisocyanate (IPDI), 200 g of polyhexyl adipate (Mn = 1000), and 150 g of acetone were added to a four-necked round-bottom flask equipped with a nitrogen inlet and outlet. The mixture was stirred at 45-55 °C until the NCO content reached 6.64 wt%. The temperature was raised to 65-75 °C, and 20.2 g of dimethylolpropionate (DMPA), 2.6 g of 1,4-neopentyl glycol (NPG), 5.3 g of dipentaerythritol, and 60 g of acetone were added. The reaction was continued with stirring until the NCO content reached 1.52 wt%. Then, 5.42 g of hydroxyethyl methacrylate (HEMA), 20.84 g of perfluorodecaol, and 30 g of acetone were added, and the reaction was continued with stirring until the characteristic NCO peak in the infrared radiation completely disappeared. The mixture was cooled to 40-45℃ and neutralized with 15.2g of triethylamine for about 5 minutes. Then, the mixture was dispersed by adding 548g of water. After dispersion, acetone was separated by distillation to obtain a solvent-free dispersion with a solid content of 35wt%.

[0043] Preparation of polybutadiene-modified waterborne UV resin E:

[0044] 66.7 g of dehydrated IPDI, 52.4 g of dicyclohexylmethane diisocyanate (HMDI), 100 g of hydroxyl-terminated polybutadiene (Mn = 1500), 50 g of polycarbonate diol (Mn = 1000), and 100 g of acetone were added to a four-necked round-bottom flask equipped with a nitrogen inlet and outlet. The mixture was stirred at 45-55 °C until the NCO content reached 10.93 wt%. The temperature was raised to 65-75 °C, and 16.8 g of DMPA, 14.4 g of 1,4-cyclohexanediol (CHDM), 6.4 g of dipentaerythritol, and 70 g of acetone were added. The reaction was continued with stirring until the NCO content reached 1.71 wt%. 13 g of PETA and 40 g of acetone were added, and the reaction was continued with stirring until the NCO content reached 0.8 wt%. 1.4 g of methanol was added, and the reaction was continued with stirring until the characteristic NCO peak in the infrared radiation completely disappeared. The mixture was cooled to 40-45℃ and neutralized with 12.6g of triethylamine for about 5 minutes. Then, the mixture was dispersed by adding 570g of water. After dispersion, acetone was separated by distillation to obtain a solvent-free dispersion with a solid content of 35wt%.

[0045] Preparation and performance testing of waterborne UV-cured wood coatings:

[0046] The polybutadiene and fluorinated modified waterborne UV resin prepared in this invention were added as the main resin to waterborne UV-cured wood coatings, and their final application performance was tested in comparison with conventional waterborne UV coatings. The composition of the test formulation is shown in Table 1, and all specific gravity values ​​are weight percentages.

[0047] Table 1

[0048]

[0049]

[0050] The test results of waterborne UV-cured wood coatings with different added waterborne UV resins are shown in Table 2. Examples 1, 2, and 3 correspond to the addition of resin A, resin B, and resin C, respectively; Comparative Examples 1 and 2 correspond to the addition of resin D and resin E, respectively.

[0051] Table 2

[0052] Test Project Example Example Example Comparative Example Comparative Example flexibility 5 5 5 3 5 Permeability 4.5 4.5 4.5 4.5 3 feel 4.5 4.5 4.5 4 4 hardness 4.5 4.5 4.5 4.5 4 Scratch resistance 4.5 4.5 4.5 4 4.5 Stain resistance 5 5 5 4 3.5 Chemical resistance 5 5 5 4 3.5

[0053] *5 points is the best, 0 points is the worst.

[0054] As can be seen from the performance test results in Table 2, the coatings equipped with the polybutadiene and fluorinated modified waterborne UV resin of this invention, compared with traditional waterborne UV coatings, greatly improve the flexibility of the resin while maintaining a similar hardness, avoiding the problem of easy cracking of the paint film of waterborne UV coatings, and at the same time achieving excellent penetration and wetting properties, stain resistance and chemical resistance.

[0055] The technical features of the above embodiments can be combined in any way. For the sake of brevity, the inventors have not described all possible combinations of the technical features in the above embodiments. However, as long as the combination of these technical features is reasonable and there is no contradiction, it should be considered to be within the scope of this specification.

[0056] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent is determined by the appended claims.

Claims

1. A water-based wood coating comprising a water-based UV resin, wherein the water-based UV resin is prepared by reacting components comprising the following weight percentages: (a) Isocyanates, 19-37 wt%; (b) Non-polyoxypropylene polyols with functionality of 2–4, 46–72 wt%; (c) Compounds containing ionizable groups, 3-6 wt%; (d) Low molecular weight compounds containing polyhydroxy and / or amino groups, 1-7 wt%; (e) Hydroxyacrylate, 1-4 wt%; (f) One or more of difluoroethanol, trifluoroethanol, hexafluorobutanol, tridecafluorooctanol, perfluorooctanol, and perfluorodecanol, 1-14 wt%; Component (b) comprises a polyolefin polyol.

2. The water-based wood coating according to claim 1, characterized in that, The component (a) is selected from one or more of diisocyanates and polyisocyanates with NCO greater than 2.

3. The water-based wood coating according to claim 1, characterized in that, The component (a) is selected from one or more of toluene diisocyanate, diphenylmethane diisocyanate, isophorone diisocyanate, hexamethylene diisocyanate and dicyclohexylmethane diisocyanate.

4. The water-based wood coating according to claim 1, characterized in that, The number average molecular weight of component (b) is 300 to 8000; component (b) is one or more of polyester polyol, polyether polyol, polycarbonate polyol, polycaprolactone polyol, polyacetal polyol, polyacrylate polyol and polysiloxane polyol and polyolefin polyol.

5. The water-based wood coating according to claim 1, characterized in that, The number average molecular weight of component (b) is 500 to 5000; the polyolefin polyol is selected from hydroxyl-terminated polybutadiene of Tianyuan Aerospace Materials, and the polyester polyol is selected from polyhexanediol adipate of Greenlink Chemical.

6. The water-based wood coating according to claim 1, characterized in that, The number average molecular weight of component (b) is 1000 to 3000.

7. The water-based wood coating according to claim 1, characterized in that, The component (c) is selected from one or more of 2,2-dimethylolpropionic acid, dimethylolbutyric acid, dimethylolacetic acid, dihydroxysuccinic acid, and N-(2-aminoethyl)-2-aminoethanesulfonic acid.

8. The water-based wood coating according to claim 1, characterized in that, The component (d) is selected from one or more of ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, 3-methylpentane-1,5-pentanediol, 1,6-hexanediol, neopentanediol, 1,4-cyclohexyldiethanol, 1,2-cyclohexanediol, 1,4-cyclohexanediol, 2-ethyl-3-propylpentanediol, 2,2-dimethylpentanediol, diethylene glycol, ethanolamine, N-substituted ethanolamine, glycerol, trimethylolpropane, pentaerythritol, dipentaerythritol, ethylenediamine, and isophorone diamine.

9. The water-based wood coating according to claim 1, characterized in that, The component (e) is a compound containing a hydroxyl group and at least one (meth)acrylate group.

10. The water-based wood coating according to claim 1, characterized in that, The component (e) is selected from pentaerythritol triacrylate, hydroxyethyl methacrylate, hydroxypropyl methacrylate, hydroxybutyl methacrylate, polyoxyethylene mono(meth)acrylate, polyoxypropylene mono(meth)acrylate, or any hydroxylated monomer that is further reacted with lactone or lactone.

11. The water-based wood coating according to claim 1, characterized in that, The preparation method of the aqueous UV resin includes the following steps: At 45-90℃, components (a) and (b) and solvent were added to a reactor to prepare a prepolymer of terminal isocyanate. Then, components (c), (d), and solvent were added to continue the chain extension reaction. After the reaction was completed, components (e) and (f) and solvent were added to continue the end-capping reaction. After the reaction was completed, a neutralizing agent was added to neutralize the reaction. Then, deionized water was added under high-speed mechanical dispersion to obtain an aqueous UV dispersion containing solvent. The solvent was removed by distillation to obtain an aqueous UV resin emulsion based on polybutadiene and fluorination modification.

12. The water-based wood coating according to claim 11, characterized in that, The neutralizing agent includes triethylamine and / or dimethylethanolamine.

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