Modified light-cured epoxy acrylic resin and preparation process thereof

Abstract

The invention relates to the field of epoxy acrylic resin, and particularly discloses modified light-cured epoxy acrylic resin and a preparation process thereof. The modified light-cured epoxy acrylic resin is prepared from the following raw materials in parts by weight: 30 to 40 parts of organic silicon modified epoxy resin, 18 to 25 parts of acrylic monomers, 0.3 to 0.7 part of a photoinitiator, 0.5 to 2.5 parts of a polymerization inhibitor, 0.2 to 0.6 part of a catalyst and 1 to 4 parts of a silane coupling agent. The organic silicon modified epoxy resin is prepared by copolymerizing epoxy resin, a methyl phenyl organic silicon oligomer and a flexibility reinforcing agent; in addition, the preparation method provided by the invention has the advantage of improving the toughness and weather resistance of the light-cured epoxy acrylic resin.

Description

Technical Field

[0001] The present application relates to the field of epoxy acrylic resin, and more specifically, to a modified light-cured epoxy acrylic resin and a preparation process thereof. Background Art

[0002] Epoxy acrylic resin is a widely used UV curing product. Epoxy acrylic resin is made by esterification reaction of acrylic resin and epoxy resin under the action of catalyst. It is the main component of light-curing coatings. Light-curing coatings have the advantages of rapid curing, energy saving and environmental protection. They are widely used in various fields such as industry, agriculture, transportation, construction, and national defense industry. As an important component of light-curing coatings, the performance of epoxy acrylic resin directly affects the overall performance of the coatings.

[0003] During the use of epoxy acrylic resin, the cured coating has the characteristics of high hardness and good wear resistance, but it is prone to aging and yellowing, has poor heat resistance, high brittleness, and poor impact resistance, which greatly limits the use of epoxy acrylic resin in outdoor environments. Summary of the invention

[0004] In order to improve the toughness and weather resistance of light-curing epoxy acrylic resin, the present application provides a modified light-curing epoxy acrylic resin and a preparation process.

[0005] In the first aspect, the present application provides a modified photocurable epoxy acrylic resin, which adopts the following technical scheme: a modified photocurable epoxy acrylic resin, comprising the following raw materials in parts by weight: 30-40 parts of silicone-modified epoxy resin, 18-25 parts of acrylic monomer, 0.3-0.7 parts of photoinitiator, 0.5-2.5 parts of inhibitor, 0.2-0.6 parts of catalyst, and 1-4 parts of silane coupling agent; the silicone-modified epoxy resin is prepared by copolymerization of epoxy resin, methylphenyl silicone oligomer and flexibility enhancer.

[0006] By adopting the above technical scheme, methylphenyl silicone oligomers and flexibility enhancers are added to the silicone-modified epoxy resin, which can effectively improve the toughness and impact resistance of the epoxy resin, thereby improving the brittleness and weather resistance of the epoxy resin. Acrylic monomers and silicone-modified epoxy resins are copolymerized to form modified light-cured epoxy acrylic resins, which also have good flexibility and impact resistance. Silane coupling agents can bond and cross-link with epoxy resins and acrylic monomers, further improving the hardness and density of epoxy acrylic resins, while also improving the weather resistance of epoxy acrylic resins.

[0007] Preferably, the methylphenyl silicone oligomer is copolymerized by methyltriethoxysilane, dimethyldiethoxysilane and phenyltriethoxysilane.

[0008] By adopting the above technical scheme, the methylphenyl silicone oligomer has good shear strength and toughness, and copolymerization with epoxy resin can effectively improve the impact resistance of epoxy resin. At the same time, after the methylphenyl silicone oligomer is grafted, it can be cross-linked with acrylic monomers under the action of silane coupling agent, thereby limiting the rotation of molecular chains in epoxy acrylic resin, so that the epoxy acrylic resin has good hardness and adhesion.

[0009] Preferably, the flexibility enhancer is modified silica-modified attapulgite.

[0010] By adopting the above technical scheme, attapulgite is a natural nano material with a large specific surface area and thermal stability, and has a good reinforcement effect. It can effectively improve the impact resistance of epoxy acrylic resin and improve its brittleness. At the same time, it can improve the heat resistance of epoxy acrylic resin. The surface properties of the attapulgite modified with modified silica are significantly improved, which improves the dispersibility of the flexibility enhancer in epoxy resin and methylphenyl silicone oligomer, which is beneficial to the copolymerization of the three.

[0011] Preferably, the preparation method of the modified silica-modified attapulgite comprises the following steps: adjusting the pH of the attapulgite slurry to 9-10, heating to 80-85°C, adding a sodium silicate aqueous solution and dilute sulfuric acid dropwise while stirring, reacting for 30-40 minutes after the addition is completed, adjusting the pH to neutral, continuing to stir for 30-40 minutes, filtering, washing, and drying to obtain silica-coated attapulgite; The silica-coated attapulgite is dispersed in water with high-speed stirring, and a silane coupling agent and n-butanol are added in sequence, stirred and heated to achieve azeotropy, reacted for 3-3.5 hours, distilled and dehydrated, filtered, washed and dried to obtain modified silica-modified attapulgite.

[0012] By adopting the above technical scheme, silicon dioxide is deposited on the surface of attapulgite by chemical deposition method. After the silicon dioxide-coated attapulgite is obtained, the silicon dioxide is surface treated with a silane coupling agent to improve the compatibility between silicon dioxide and epoxy resin and methylphenyl silicone oligomer, and at the same time facilitate the copolymerization of the three to form silicone-modified epoxy resin.

[0013] Preferably, the mass ratio of the silica-coated attapulgite to the silane coupling agent is (9.8-10.2):(1-1.2).

[0014] By adopting the above technical scheme and controlling the mass ratio of silica-coated attapulgite to silane coupling agent, the modification effect of silane coupling agent on silica can be effectively regulated, thereby facilitating improving the compatibility and copolymerization uniformity between the flexibility enhancer, methylphenyl silicone oligomer and epoxy resin.

[0015] Preferably, the acrylic monomers include methyl methacrylate, hydroxyethyl methacrylate and butyl acrylate in a mass ratio of (7.4-7.8):(2.3-2.8):(0.8-1.3).

[0016] By adopting the above technical scheme, methyl methacrylate is used as a hard monomer, butyl acrylate is used as a soft monomer, and hydroxyethyl methacrylate is used as a polar monomer. The copolymerization of the three can effectively adjust the hardness of the epoxy acrylic resin after curing. At the same time, hydroxyethyl methacrylate as a polar monomer can be bonded and cross-linked with the silane coupling agent and the silicone-modified epoxy resin, thereby further improving the hardness and density of the epoxy acrylic resin, and at the same time improving the weather resistance of the epoxy acrylic resin.

[0017] In a second aspect, the present application provides a preparation process of a modified light-curing epoxy acrylic resin, which adopts the following technical solution: A preparation process of a modified light-curing epoxy acrylic resin comprises the following steps: (1) Preparation of silicone-modified epoxy resin: methylphenyl silicone oligomer, flexibility enhancer and epoxy resin are added to toluene, stirred and mixed, and then butyltin dilaurate is added dropwise. The temperature is raised to 130-140° C., reacted for 4-5 hours, and toluene is removed by reduced pressure distillation to obtain silicone-modified epoxy resin. (2) Preparation of modified photocurable epoxy acrylate resin: After mixing the organosilicon-modified epoxy resin, the polymerization inhibitor and the silane coupling agent, the temperature is raised to 110-120°C, and a uniform mixture of the photoinitiator, the catalyst and the acrylic monomer is added dropwise, and the reaction is kept at this temperature for 5-6 hours. After the reaction is terminated, the modified photocurable epoxy acrylate resin is cooled to room temperature.

[0018] By adopting the above technical scheme, methylphenyl silicone oligomer, flexibility enhancer and epoxy resin are copolymerized under the action of butyltin dilaurate to form a copolymer silicone-modified epoxy resin, and silicone and attapulgite are introduced into the epoxy resin to effectively improve the flexibility and weather resistance of the silicone-modified epoxy resin. The silicone-modified epoxy resin is polymerized with acrylic monomers under the action of a catalyst, and the synthesized modified light-curing epoxy acrylic resin has good flexibility and weather resistance.

[0019] Preferably, in the preparation of the silicone-modified epoxy resin, the mixing speed is 280-320 r / min, and the reaction speed is 550-600 r / min. In the preparation of the modified light-curing epoxy acrylic resin, the mixing speed is 270-310 r / min, and the reaction speed is 450-530 r / min.

[0020] By adopting the above technical solution, the appropriate mixing speed allows the raw materials to be fully mixed and evenly mixed, and the reaction speed is increased, so that the polymerization raw materials can fully contact and polymerize during the polymerization process, reducing violent polymerization and uneven reaction.

[0021] In summary, this application has the following beneficial effects: 1. Since the present application adopts silicone-modified epoxy resin, methylphenyl silicone oligomers and flexibility enhancers are added to the silicone-modified epoxy resin, which can effectively improve the toughness and impact resistance of the epoxy resin, thereby improving the brittleness and weather resistance of the epoxy resin. Acrylic monomers and silicone-modified epoxy resins are copolymerized to form modified light-cured epoxy acrylic resins, which also have good flexibility and impact resistance. Silane coupling agents can bond and cross-link with epoxy resins and acrylic monomers, further improving the hardness and density of epoxy acrylic resins, while improving the weather resistance of epoxy acrylic resins.

[0022] 2. The methylphenyl silicone oligomer in the present application has good shear strength and toughness, and copolymerization with epoxy resin can effectively improve the impact resistance of epoxy resin. At the same time, after grafting, the methylphenyl silicone oligomer can be cross-linked with acrylic monomers under the action of silane coupling agent, restricting the rotation of molecular chains in epoxy acrylic resin, so that the epoxy acrylic resin has good hardness and adhesion.

[0023] 3. In the present application, the attapulgite is a natural nanomaterial with a large specific surface area and thermal stability, and has a good reinforcement effect. It can effectively improve the impact resistance of epoxy acrylic resin, improve its brittleness, and at the same time improve the heat resistance of epoxy acrylic resin. The surface properties of the attapulgite modified with modified silica are significantly improved, which improves the dispersibility of the flexibility enhancer in epoxy resin and methylphenyl silicone oligomer, and is beneficial to the copolymerization of the three. DETAILED DESCRIPTION

[0024] The present application is further described in detail below with reference to the embodiments.

[0025] Preparation Example 1-7 of Flexibility Enhancer Preparation Example 1 The flexibility enhancer is modified silica-modified attapulgite. The preparation method of modified silica-modified attapulgite comprises the following steps: using 1 mol / L sodium silicate aqueous solution, adjusting the pH of attapulgite slurry with a solid content of 0.05 g / mL to 9, heating to 80°C, adding 0.2 mol / L sodium silicate aqueous solution and 0.2 mol / L dilute sulfuric acid dropwise while stirring, so that the temperature is maintained at 80°C, the mass ratio of sodium silicate to attapulgite is 2:5, the pH is 10, after the addition is completed, reacting for 30 minutes, adjusting the pH to neutral, continuing stirring for 30 minutes, filtering, washing, and drying to obtain silica-coated attapulgite; The silica-coated attapulgite is dispersed in water with high-speed stirring, and a silane coupling agent is added, wherein the mass ratio of the silica-coated attapulgite to the silane coupling agent is 9.8:1, and then n-butanol is added, wherein the n-butanol content is 12wt%, and the mixture is stirred and heated to achieve azeotropy, and the reaction is performed for 3h, and the mixture is dehydrated by distillation, filtered, washed, and dried to obtain modified silica-modified attapulgite.

[0026] Preparation Example 2 The flexibility enhancer is modified silica-modified attapulgite. The preparation method of modified silica-modified attapulgite comprises the following steps: using 1.2 mol / L sodium silicate aqueous solution, adjusting the pH of attapulgite slurry with a solid content of 0.06 g / mL to 10, heating to 85°C, adding 0.2 mol / L sodium silicate aqueous solution and 0.2 mol / L dilute sulfuric acid dropwise while stirring, so that the temperature is maintained at 85°C, the mass ratio of sodium silicate to attapulgite is 2.1:5.3, the pH is 11, after the addition is completed, reacting for 40 minutes, adjusting the pH to neutral, continuing to stir for 40 minutes, filtering, washing, and drying to obtain silica-coated attapulgite; The silica-coated attapulgite was dispersed in water with high-speed stirring, and a silane coupling agent was added, wherein the mass ratio of the silica-coated attapulgite to the silane coupling agent was 10.2:1.2. Then, n-butanol was added, wherein the n-butanol content was 14 wt %. The mixture was stirred and heated to achieve azeotropy, and the reaction was carried out for 3.5 hours. The mixture was dehydrated by distillation, filtered, washed, and dried to obtain modified silica-modified attapulgite.

[0027] Preparation Example 3 The flexibility enhancer is modified silica-modified attapulgite. The preparation method of modified silica-modified attapulgite comprises the following steps: using 1.1 mol / L sodium silicate aqueous solution, adjusting the pH of attapulgite slurry with a solid content of 0.05 g / mL to 9, heating to 83°C, adding 0.2 mol / L sodium silicate aqueous solution and 0.2 mol / L dilute sulfuric acid dropwise while stirring, so that the temperature is maintained at 85°C, the mass ratio of sodium silicate to attapulgite is 2.2:5.1, the pH is 11, after the addition is completed, reacting for 40 minutes, adjusting the pH to neutral, continuing stirring for 40 minutes, filtering, washing, and drying to obtain silica-coated attapulgite; The silica-coated attapulgite was dispersed in water with high-speed stirring, and a silane coupling agent was added, wherein the mass ratio of the silica-coated attapulgite to the silane coupling agent was 10:1.1. Then n-butanol was added, and the n-butanol content was 13wt%. The mixture was stirred and heated to achieve azeotropy, and the reaction was carried out for 3.5h. The mixture was dehydrated by distillation, filtered, washed, and dried to obtain modified silica-modified attapulgite.

[0028] Preparation Example 4 The difference between Preparation Example 4 and Preparation Example 1 is that the mass ratio of sodium silicate to attapulgite is 2:3.

[0029] Preparation Example 5 The difference between Preparation Example 5 and Preparation Example 1 is that the mass ratio of sodium silicate to attapulgite is 2:7.

[0030] Preparation Example 6 The difference between Preparation Example 6 and Preparation Example 1 is that the mass ratio of silica-coated attapulgite to the silane coupling agent is 9.8:0.7.

[0031] Preparation Example 7 The difference between Preparation Example 7 and Preparation Example 1 is that the mass ratio of silica-coated attapulgite to the silane coupling agent is 9.8:1.7.

[0032] Preparation Example of Methylphenyl Silicone Oligomer Preparation Example 8 After mixing 18.26g of methyltriethoxysilane, dimethyldiethoxysilane and phenyltriethoxysilane in a molar ratio of 0.1:0.24:0.25, 14.2g of 0.62wt% hydrochloric acid was dropped, and the mixture was reacted at 25°C for 0.5h. The mixture was heated to 80°C and reacted for 3.5h. Then, excess sodium bicarbonate was added, the pH was adjusted to neutral, and then vacuum distillation was performed to remove ethanol and unreacted monomers. The mixture was cooled to obtain methylphenyl silicone oligomer. Example

[0033] Example 1 A modified light-curing epoxy acrylic resin comprises the following raw materials in parts by weight: 30 kg of organosilicon-modified epoxy resin, 18 kg of acrylic monomer, 0.3 kg of photoinitiator, 0.5 kg of polymerization inhibitor, 0.2 kg of catalyst and 1 kg of silane coupling agent; the organosilicon-modified epoxy resin is prepared by copolymerizing epoxy resin, methylphenyl silicone oligomer and flexibility enhancer, the epoxy resin is bisphenol A epoxy resin E51, the methylphenyl silicone oligomer is the methylphenyl silicone oligomer prepared in Preparation Example 8, the flexibility enhancer is the flexibility enhancer prepared in Preparation Example 1, the acrylic monomer comprises methyl methacrylate, hydroxyethyl methacrylate and butyl acrylate in a mass ratio of 7.4:2.3:0.8, the photoinitiator is benzophenone, the polymerization inhibitor is p-hydroxyanisole, the catalyst is tetrabutylammonium bromide, and the silane coupling agent is KH570.

[0034] The preparation process of the modified light-curing epoxy acrylic resin comprises the following steps: (1) Preparation of silicone-modified epoxy resin: 38 kg of methylphenyl silicone oligomer, 4 kg of flexibility enhancer and 39 kg of epoxy resin were added to 24 kg of toluene, and after stirring at a speed of 280 r / min, 0.4 kg of butyltin dilaurate was added dropwise, and the temperature was raised to 130° C., and the reaction was carried out for 5 hours, and the stirring speed was 550 r / min. After the reaction was completed, the toluene was removed by reduced pressure distillation to obtain a silicone-modified epoxy resin; (2) Preparation of modified photocurable epoxy acrylate resin: After mixing the organosilicon-modified epoxy resin, the polymerization inhibitor and the silane coupling agent at a speed of 270 r / min, the temperature is raised to 110°C, and a uniform mixture of the photoinitiator, the catalyst and the acrylic monomer is dropped into the mixture. The mixture is kept warm and stirred at a speed of 530 r / min for 6 hours. The reaction is terminated and the temperature is cooled to obtain the modified photocurable epoxy acrylate resin.

[0035] Example 2 A modified light-curing epoxy acrylic resin comprises the following raw materials in parts by weight: 40 kg of organosilicon-modified epoxy resin, 25 kg of acrylic monomer, 0.7 kg of photoinitiator, 2.5 kg of polymerization inhibitor, 0.6 kg of catalyst and 4 kg of silane coupling agent; the organosilicon-modified epoxy resin is prepared by copolymerizing epoxy resin, methylphenyl silicone oligomer and flexibility enhancer, the epoxy resin is bisphenol A epoxy resin E51, the methylphenyl silicone oligomer is the methylphenyl silicone oligomer prepared in Preparation Example 8, the flexibility enhancer is the flexibility enhancer prepared in Preparation Example 2, the acrylic monomer comprises methyl methacrylate, hydroxyethyl methacrylate and butyl acrylate in a mass ratio of 7.8:2.8:1.3, the photoinitiator is benzophenone, the polymerization inhibitor is p-hydroxyanisole, the catalyst is tetrabutylammonium bromide, and the silane coupling agent is KH570.

[0036] The preparation process of the modified light-curing epoxy acrylic resin comprises the following steps: (1) Preparation of silicone-modified epoxy resin: 42 kg of methylphenyl silicone oligomer, 4.3 kg of flexibility enhancer and 40 kg of epoxy resin were added to 24 kg of toluene, and after stirring at a speed of 320 r / min, 0.4 kg of butyltin dilaurate was added dropwise, and the temperature was raised to 140° C., and the mixture was reacted for 4 h, and stirred at a speed of 600 r / min. After the reaction was completed, the toluene was removed by reduced pressure distillation to obtain a silicone-modified epoxy resin; (2) Preparation of modified photocurable epoxy acrylate resin: After mixing the organosilicon-modified epoxy resin, the polymerization inhibitor and the silane coupling agent at a speed of 310 r / min, the temperature is raised to 120°C, and a uniform mixture of the photoinitiator, the catalyst and the acrylic monomer is dropped into the mixture. The mixture is kept warm and stirred at a speed of 450 r / min for 5 hours. The reaction is terminated and the temperature is cooled to obtain the modified photocurable epoxy acrylate resin.

[0037] Example 3 A modified light-curing epoxy acrylic resin comprises the following raw materials in parts by weight: 35 kg of organosilicon-modified epoxy resin, 22 kg of acrylic monomer, 0.5 kg of photoinitiator, 1.8 kg of polymerization inhibitor, 0.5 kg of catalyst and 3 kg of silane coupling agent; the organosilicon-modified epoxy resin is prepared by copolymerizing epoxy resin, methylphenyl silicone oligomer and flexibility enhancer, the epoxy resin is bisphenol A epoxy resin E51, the methylphenyl silicone oligomer is the methylphenyl silicone oligomer prepared in Preparation Example 8, the flexibility enhancer is the flexibility enhancer prepared in Preparation Example 3, the acrylic monomer comprises methyl methacrylate, hydroxyethyl methacrylate and butyl acrylate in a mass ratio of 7.6:2.5:1.1, the photoinitiator is benzophenone, the polymerization inhibitor is p-hydroxyanisole, the catalyst is tetrabutylammonium bromide and the silane coupling agent is KH570.

[0038] The preparation process of the modified light-curing epoxy acrylic resin comprises the following steps: (1) Preparation of silicone-modified epoxy resin: 40 kg of methylphenyl silicone oligomer, 4.1 kg of flexibility enhancer and 39 kg of epoxy resin were added to 24 kg of toluene, and the mixture was stirred at a speed of 280-320 r / min, and then 0.4 g of butyltin dilaurate was added dropwise. The mixture was heated to 135° C., reacted for 4 h, and stirred at a speed of 550 r / min. After the reaction was completed, the toluene was removed by vacuum distillation to obtain a silicone-modified epoxy resin. (2) Preparation of modified photocurable epoxy acrylate resin: After mixing the organosilicon-modified epoxy resin, the polymerization inhibitor and the silane coupling agent at a speed of 290 r / min, the temperature is raised to 120°C, and a uniform mixture of the photoinitiator, the catalyst and the acrylic monomer is dropped into the mixture. The mixture is kept warm and stirred at a speed of 510 r / min for 5 hours. The reaction is terminated and the temperature is cooled to obtain the modified photocurable epoxy acrylate resin.

[0039] Example 4 The difference between Example 4 and Example 1 is that in Example 4, the flexibility enhancer is the flexibility enhancer prepared in Preparation Example 4.

[0040] Example 5 The difference between Example 5 and Example 1 is that in Example 5, the flexibility enhancer is the flexibility enhancer prepared in Preparation Example 5.

[0041] Example 6 The difference between Example 6 and Example 1 is that in Example 6, the flexibility enhancer is the flexibility enhancer prepared in Preparation Example 6.

[0042] Example 7 The difference between Example 7 and Example 1 is that in Example 7, the flexibility enhancer is the flexibility enhancer prepared in Preparation Example 8.

[0043] Example 8 The difference between Example 8 and Example 1 is that the acrylic monomer includes methyl methacrylate, hydroxyethyl methacrylate and butyl acrylate in a mass ratio of 8.3:2.3:0.8.

[0044] Example 9 The difference between Example 9 and Example 1 is that the acrylic monomer includes methyl methacrylate, hydroxyethyl methacrylate and butyl acrylate in a mass ratio of 7.4:3.2:0.8.

[0045] Example 10 The difference between Example 10 and Example 1 is that the acrylic monomer includes methyl methacrylate, hydroxyethyl methacrylate and butyl acrylate in a mass ratio of 7.4:2.3:1.8.

[0046] Comparative Example Comparative Example 1 The difference between Comparative Example 1 and Example 1 is that in Comparative Example 1, an equal amount of double type A epoxy resin E51 is used to replace the silicone-modified epoxy resin.

[0047] Comparative Example 2 The difference between Comparative Example 2 and Example 1 is that in Comparative Example 2, an equal amount of methyl methacrylate is used instead of the acrylic monomer.

[0048] Comparative Example 3 The difference between Comparative Example 3 and Example 1 is that in Comparative Example 3, an equal amount of butyl acrylate is used instead of the acrylic monomer.

[0049] Comparative Example 4 The difference between Comparative Example 4 and Example 1 is that in Comparative Example 4, an equal amount of methyltriethoxysilane is used instead of methylphenyl silicone oligomer.

[0050] Comparative Example 5 The difference between Comparative Example 5 and Example 1 is that in Comparative Example 5, an equal amount of dimethyldiethoxysilane is used instead of methylphenyl silicone oligomer.

[0051] Comparative Example 6 The difference between Comparative Example 6 and Example 1 is that in Comparative Example 6, an equal amount of phenyltriethoxysilane is used instead of methylphenyl silicone oligomer.

[0052] Comparative Example 7 The difference between Comparative Example 7 and Example 1 is that in Comparative Example 7, the added amount of each raw material is 50kg of silicone-modified epoxy resin, 18kg of acrylic monomer, 0.3kg of photoinitiator, 0.5kg of inhibitor, 0.2kg of catalyst, and 1kg of silane coupling agent, and the selection of each raw material is the same as that in Example 1.

[0053] Comparative Example 8 The difference between Comparative Example 8 and Example 1 is that in Comparative Example 8, the added amount of each raw material is 30kg of silicone-modified epoxy resin, 35kg of acrylic monomer, 0.3kg of photoinitiator, 0.5kg of inhibitor, 0.2kg of catalyst, and 1kg of silane coupling agent, and the selection of each raw material is the same as that in Example 1.

[0054] Comparative Example 9 The difference between Comparative Example 9 and Example 1 is that in Comparative Example 9, no flexibility enhancer is added.

[0055] Detection Methods The modified light-curable epoxy acrylic resins prepared in Examples 1-10 and Comparative Examples 1-9 were mixed with deionized water, stirred at 300 r / min for 50 min to obtain a modified light-curable epoxy acrylic resin emulsion, and applied to the surface of the steel plate substrate. The coating thickness was 80 μm. After curing for 80 seconds under ultraviolet light at a lamp distance of 15 cm, the hardness, adhesion and weather resistance of the cured coating were tested. The hardness test referred to "GB 6739-2006 Paint and varnish pencil method for determination of paint film hardness", the adhesion test referred to "GB / T 9286-1998 Paint and varnish film cross-cut test", and the weather resistance test referred to "GB / T 1767-1979 Paint film weather resistance determination method", and the results were recorded in Table 1. According to GB / T 2567-2008 "Test Method for Properties of Resin Castings" tests the notched impact strength of the modified light-curing epoxy acrylic resin emulsions prepared in the examples and comparative examples after UV curing. The sample size is 80mm×10mm×4mm, with a V-notch and a depth of 2mm. The results are recorded in Table 1.

[0056] Table 1 Performance test of coating According to Table 1 and Examples 1-3, it can be seen that the modified light-cured epoxy acrylic resin prepared in Examples 1-3 can be cured in a relatively short time, and the cured coating has good hardness and adhesion, and good weather resistance and impact resistance, so that the brittleness and weather resistance of the prepared coating are improved, while the wear resistance and hardness are not reduced. In Examples 1-3, silicone-modified epoxy resin and acrylic monomer are copolymerized. The silicone-modified epoxy resin is copolymerized by methylphenyl silicone oligomer, flexibility enhancer and epoxy resin. The methylphenyl silicone oligomer is copolymerized by methyltriethoxysilane, dimethyldiethoxysilane and phenyltriethoxysilane, and has good shear strength and toughness. The methylphenyl silicone oligomer can effectively improve the impact resistance of the epoxy resin, and after the methylphenyl silicone oligomer is grafted on the epoxy resin, it can be cross-linked with the acrylic monomer under the action of the silane coupling agent, which not only improves the restriction of the rotation of the molecular chain in the epoxy acrylic resin, but also improves the hardness and adhesion of the epoxy acrylic resin.

[0057] The flexibility enhancer is modified silica-modified attapulgite. Attapulgite has a large specific surface area and good reinforcement effect. Silica is deposited on the surface of the attapulgite, and after surface treatment with a silane coupling agent, the surface properties are significantly improved, which is conducive to the uniform dispersion of the flexibility enhancer in the epoxy resin and methylphenyl silicone oligomer, making the flexibility enhancer more tightly combined with the epoxy resin and methylphenyl silicone oligomer. The silicone-modified epoxy resin formed by the copolymerization of the three has good impact resistance, heat resistance and weather resistance.

[0058] Acrylic monomers include methyl methacrylate, hydroxyethyl methacrylate and butyl acrylate. Methyl methacrylate is a hard monomer and can provide good hardness for epoxy acrylic resin. Butyl acrylate is a soft monomer and can effectively improve the brittleness of epoxy acrylic. Hydroxyethyl methacrylate, as a polar monomer, can be cross-linked with silane coupling agent and silicone modified epoxy resin, further improving the cross-linking degree and density of epoxy acrylic resin, while making the silane coupling agent and silicone modified epoxy resin deeply cross-linked with acrylic monomers, which is beneficial to improving the weather resistance of epoxy acrylic resin.

[0059] Combining Examples 1-3 and 4-5, it can be seen that the impact resistance of the epoxy acrylic resin prepared in Example 4-5 is reduced. The flexibility enhancer used in Example 4-5 changes the mass ratio of sodium silicate to attapulgite during preparation. The mass ratio of sodium silicate to attapulgite directly affects the amount of silica deposition on the surface of attapulgite. When the amount of sodium silicate added is reduced, the silica loading on the surface of attapulgite is reduced, and the attapulgite surface is not completely covered, thereby reducing the compatibility of attapulgite with epoxy resin. When the amount of sodium silicate added is increased, the amount of silica deposition is too much, forming more silica particles, and the loading on the surface of attapulgite is not increased.

[0060] Combining Examples 1-3 and 6-7, it can be seen that the impact resistance of the epoxy acrylic resin prepared in Example 6-7 is reduced. When preparing the flexibility enhancer used in Example 6-7, the mass ratio of the silane coupling agent to the silica-coated attapulgite was changed, indicating that the amount of silane coupling agent added has an impact on the effect of surface treatment modification. Too much or too little addition of the silane coupling agent can easily reduce the surface treatment effect, thereby reducing the impact resistance of the epoxy acrylic resin.

[0061] Combining Examples 1-3 and Examples 8-10, it can be seen that the epoxy acrylic resin prepared in Examples 8-10 has changed in terms of impact resistance, adhesion and hardness. In Example 8, the amount of methyl methacrylate added in the acrylic monomer is increased. Methyl methacrylate is a hard monomer. Too much addition of methyl methacrylate can easily make the epoxy acrylic formed by polymerization have good adhesion, increased hardness, improved brittleness, and reduced impact resistance. In Example 9, the amount of hydroxyethyl methacrylate added is increased. Hydroxyethyl methacrylate is a functional monomer and a polar monomer. Too much addition can easily slow down the curing speed of the epoxy acrylic resin formed by polymerization. In the experiment of this application, the curing time remains unchanged, so that the impact resistance, hardness and adhesion of the coating film after curing in Example 9 are all reduced. The reduction in weather resistance is due to the excessive addition of polar monomers, which reduces the structural density of the epoxy acrylic formed by cross-linking and increases the brittleness. In Example 10, the amount of butyl acrylate added is increased. Butyl acrylate is a soft monomer. Too much addition of butyl acrylate can easily reduce the hardness of the epoxy acrylic resin and reduce the adhesion.

[0062] Combining Examples 1-3 and Comparative Example 1, it can be seen that the epoxy resin used in Comparative Example 1 has not been modified with silicone, and the weather resistance and impact resistance of the epoxy acrylic resin obtained are both reduced. The silicone-modified epoxy resin introduces silicone oligomers and flexibility enhancers, which can effectively reinforce the epoxy acrylic resin and improve the toughness and weather resistance of the epoxy acrylic resin. The epoxy resin in Comparative Example 1 has not been modified with silicone, which makes the epoxy acrylic resin more brittle, and the double bonds and other groups in the epoxy resin are easily oxidized, resulting in poor weather resistance.

[0063] Combining Examples 1-3 and Comparative Examples 2-3, it can be seen that only one acrylic monomer is added in Comparative Examples 2-3, which changes the properties of the epoxy acrylic resin in terms of hardness and impact resistance. In Comparative Example 2, only methyl methacrylate is added. The addition of the hard monomer increases the hardness of the epoxy acrylic resin and reduces its impact resistance. In Comparative Example 3, only butyl acrylate is added. The addition of the soft monomer reduces the hardness of the epoxy acrylic resin and improves its impact resistance. At the same time, the absence of methyl methacrylate reduces the adhesion.

[0064] Combining Examples 1-3 and Comparative Examples 4-6, it can be seen that in Comparative Example 4-6, the methylphenyl silicone oligomer is replaced with a silane monomer, and the epoxy acrylic resin prepared in Comparative Example 4-6 has decreased in impact resistance, weather resistance, etc., indicating that the effect of using the three alone to modify the epoxy resin is not as good as the effect of modifying the epoxy resin after the three are copolymerized to form a methylphenyl silicone oligomer. The three are copolymerized to form a methylphenyl silicone oligomer containing hydroxyl groups, which can be interlaced and cross-linked with the molecular chain of the epoxy resin during the copolymerization process to form a silicone-modified epoxy resin. Silicone has a strong deformation ability, thereby effectively improving the impact resistance of the silicone-modified epoxy resin, thereby improving the impact resistance of the epoxy acrylic resin.

[0065] Combining Examples 1-3 and Comparative Examples 7-9, it can be seen that the amounts of silicone-modified epoxy resin, acrylic monomer and flexibility enhancer are changed in Comparative Examples 7-9, respectively. The epoxy acrylic resins prepared in Comparative Examples 7-9 have changes in impact resistance, adhesion and impact resistance. In Comparative Example 7, the amount of silicone-modified epoxy resin is increased. The increase of epoxy resin improves the hardness and adhesion of the epoxy acrylic resin, while reducing the impact resistance of the epoxy acrylic resin. In Comparative Example 8, the amount of acrylic monomer is increased. The increase of acrylic monomer reduces the content of rigid structures such as benzene rings, thereby reducing the hardness and adhesion of the epoxy acrylic resin. In Comparative Example 9, no flexibility enhancer is added. As an inorganic fiber, the flexibility enhancer has a good reinforcing effect on the epoxy acrylic resin, and can effectively improve the impact resistance and toughness of the epoxy acrylic resin. In Comparative Example 9, no flexibility enhancer is added, which results in poor impact resistance.

[0066] This specific embodiment is merely an explanation of the present application and is not a limitation of the present application. After reading this specification, those skilled in the art may make modifications to the present embodiment without any creative contribution as needed, but such modifications are protected by the patent law as long as they are within the scope of the claims of the present application.

Claims

1. A modified light-curing epoxy acrylic resin, characterized in that: The invention comprises the following raw materials in parts by weight: 30-40 parts of organosilicon-modified epoxy resin, 18-25 parts of acrylic monomer, 0.3-0.7 parts of photoinitiator, 0.5-2.5 parts of polymerization inhibitor, 0.2-0.6 parts of catalyst and 1-4 parts of silane coupling agent; the organosilicon-modified epoxy resin is prepared by copolymerizing epoxy resin, methylphenyl organosilicon oligomer and flexibility enhancer.

2. The modified light-curing epoxy acrylic resin according to claim 1, characterized in that: The methylphenyl organic silicon oligomer is prepared by copolymerization of methyltriethoxysilane, dimethyldiethoxysilane and phenyltriethoxysilane.

3. The modified light-curing epoxy acrylic resin according to claim 1, characterized in that: The flexibility enhancer is modified silica-modified attapulgite.

4. A modified light-curing epoxy acrylic resin according to claim 3, characterized in that: The preparation method of modified silica-modified attapulgite comprises the following steps: adjusting the pH of the attapulgite slurry to 9-10, heating it to 80-85° C., adding a sodium silicate aqueous solution and dilute sulfuric acid dropwise while stirring, reacting for 30-40 minutes after the addition is completed, adjusting the pH to neutral, continuing to stir for 30-40 minutes, filtering, washing, and drying to obtain silica-coated attapulgite; The silica-coated attapulgite is dispersed in water with high-speed stirring, and a silane coupling agent and n-butanol are added in sequence, stirred and heated to achieve azeotropy, reacted for 3-3.5 hours, distilled and dehydrated, filtered, washed and dried to obtain modified silica-modified attapulgite.

5. A modified light-curing epoxy acrylic resin according to claim 4, characterized in that: The mass ratio of the silica-coated attapulgite to the silane coupling agent is (9.8-10.2):(1-1.2).

6. The modified light-curing epoxy acrylic resin according to claim 1, characterized in that: The acrylic monomers include methyl methacrylate, hydroxyethyl methacrylate and butyl acrylate in a mass ratio of (7.4-7.8):(2.3-2.8):(0.8-1.3).

7. A process for preparing a modified light-curing epoxy acrylic resin, characterized in that: The following steps are involved: (1) Preparation of silicone-modified epoxy resin: methylphenyl silicone oligomer, flexibility enhancer and epoxy resin are added to toluene, stirred and mixed, and then butyltin dilaurate is added dropwise. The temperature is raised to 130-140°C, and the reaction is carried out for 4-5 hours. The toluene is removed by vacuum distillation to obtain silicone-modified epoxy resin. (2) Preparation of modified photocurable epoxy acrylate resin: After mixing the organosilicon-modified epoxy resin, polymerization inhibitor and silane coupling agent, heat it to 110-120°C, drop a uniform mixture of photoinitiator, catalyst and acrylic monomer, keep the temperature for 5-6 hours, terminate the reaction, and cool to room temperature to obtain the modified photocurable epoxy acrylate resin.

8. The modified light-curing epoxy acrylic resin and preparation process according to claim 7, characterized in that: In the preparation of the silicone-modified epoxy resin, the mixing speed is 280-320 r / min and the reaction speed is 550-600 r / min. In the preparation of the modified light-curing epoxy acrylic resin, the mixing speed is 270-310 r / min and the reaction speed is 450-530 r / min.

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