阅读说明：本技术 一种核壳型含氟乳液微球的制备方法及其在超疏水涂料中的应用 (Preparation method of core-shell type fluorine-containing emulsion microsphere and application of core-shell type fluorine-containing emulsion microsphere in super-hydrophobic coating ) 是由 徐安厚 李文薇 王瑞雪 王咸廷 李辉 耿兵 于 2019-11-05 设计创作，主要内容包括：本发明属于高分子材料制备技术领域,具体涉及一种核壳型含氟乳液微球的制备方法及其在超疏水涂料中的应用。该方法具体通过以下步骤实现：(1)向反应瓶中加入乳化剂、单体和去离子水,搅拌混合,升温,加入引发剂,保温反应,制得种子乳液；(2)向制得种子乳液中,加入去离子水,乳化剂,引发剂、混合单体A,开动搅拌混合,升温反应,反应结束后滴加混合单体B,滴加完毕,再继续反应,降温即得。本发明制备的核壳结构含氟乳液微球,粒径可调,核壳的软硬度可调,微球表面氟含量可调控。利用该微球制备的氟涂料,大大增加了涂料的自清洁能力,表现为超疏水性,兼具抗菌、防油防污、环保等性能,有效节约能耗,对环境友好,市场前景广阔。(The invention belongs to the technical field of high polymer material preparation, and particularly relates to a preparation method of core-shell type fluorine-containing emulsion microspheres and application of the core-shell type fluorine-containing emulsion microspheres in super-hydrophobic coating. The method is realized by the following steps: (1) adding an emulsifier, a monomer and deionized water into a reaction bottle, stirring and mixing, heating, adding an initiator, and carrying out heat preservation reaction to prepare a seed emulsion; (2) adding deionized water, an emulsifier, an initiator and a mixed monomer A into the prepared seed emulsion, starting stirring and mixing, heating for reaction, dropwise adding the mixed monomer B after the reaction is finished, continuing the reaction after the dropwise adding is finished, and cooling to obtain the product. The fluorine-containing emulsion microsphere with the core-shell structure prepared by the invention has adjustable particle size, adjustable core-shell hardness and adjustable fluorine content on the surface of the microsphere. The fluorine coating prepared by the microspheres has the advantages of greatly improving the self-cleaning capability of the coating, showing super-hydrophobicity, having the performances of antibiosis, oil resistance, pollution prevention, environmental protection and the like, effectively saving energy consumption, being environment-friendly and having wide market prospect.)

1. The preparation method of the core-shell fluorine-containing emulsion microsphere is characterized by comprising the following steps:

(1) firstly, adding an emulsifier, a monomer and deionized water into a reaction bottle, stirring and mixing, heating to 50-80 ℃, adding an initiator, and carrying out heat preservation reaction for 4-6 hours to prepare a seed emulsion;

(2) adding deionized water, an emulsifier, an initiator and a mixed monomer A into the prepared seed emulsion, starting stirring and mixing, heating to 30-50 ℃, preserving heat for 0.5-2 hours, heating to 60-80 ℃ for reaction, starting dropwise adding the mixed monomer B after reacting for 0.5-2 hours, finishing dropwise adding after 1-5 hours, continuing to react for 3-12 hours, and cooling to obtain the core-shell fluorine-containing emulsion microsphere.

2. The method according to claim 1, wherein in the step (1), the mass ratio of the emulsifier, the monomer, the initiator and the deionized water is (0.2-1): 5-10): 0.005-0.1): 20-50.

3. The preparation method according to claim 2, wherein in the step (1), the emulsifier is sodium dodecyl sulfate and OP-10, and the mass ratio of the sodium dodecyl sulfate to the OP-10 is (1-3): 1; the monomer is a mixture of styrene and divinylbenzene, and the mixing mass ratio is (3-10): 1; the initiator is potassium persulfate or ammonium persulfate.

4. The preparation method according to claim 1, wherein in the step (2), the mass ratio of the deionized water, the emulsifier, the initiator and the mixed monomer is (20-80): 1-0.2: (0.01-0.2): 10-20);

the mixed monomer is the sum of the mixed monomer A and the mixed monomer B.

5. The preparation method according to claim 4, wherein in the step (2), the emulsifier is a mixture of sodium dodecyl sulfate and OP-10, and the mass ratio of the mixture to the emulsifier is (1-0.5): 1; the ratio of the seed emulsion to the water is 1: 2-1: 6; the mixed monomer A is prepared from styrene, butyl acrylate and fluorine-containing acrylate according to the mass ratio of (1-3): (1-4): (0.1-1); the mixed monomer B is prepared from styrene, butyl acrylate and fluorine-containing acrylate according to the mass ratio of (1-3): (1-4): (1-4); the mass ratio of the mixed monomer A to the mixed monomer B is 1 (1-4), and the initiator is potassium persulfate or ammonium persulfate.

6. The method according to claim 5, wherein the fluorine-containing acrylate is dodecafluoroheptyl methacrylate, dodecafluoroheptyl acrylate, hexafluorobutyl methacrylate, hexafluorobutyl acrylate, tridecyl octyl methacrylate, or a mixture of two or more of the above monomers.

7. The application of the core-shell type fluorine-containing emulsion microspheres prepared by the preparation method of any one of claims 1 to 6 in preparing super-hydrophobic weather-resistant coatings.

8. The application of claim 7, wherein the super-hydrophobic weather-resistant coating is prepared by mixing 5-12 parts of core-shell type fluorine-containing emulsion microspheres, 45-75 parts of aqueous fluorocarbon emulsion, 20 parts of titanium dioxide, 0.5 part of dispersing agent, 0.5 part of defoaming agent, 0.6 part of leveling agent, 0.2-0.4 part of thickening agent and 18 parts of deionized water; the content of the core-shell type fluorine-containing emulsion microspheres in the coating is 3-15 wt%.

9. The use of claim 8, wherein the fluorine-containing emulsion microsphere is a core-shell emulsion with crosslinked polystyrene as a core and poly (styrene-butyl acrylate-fluoroacrylate) as a shell, the particle size is 40nm to 400nm, and the fluorine content is 1 wt% to 10 wt%.

Technical Field

The invention belongs to the technical field of high polymer material preparation, and particularly relates to a preparation method of core-shell type fluorine-containing emulsion microspheres and application of the core-shell type fluorine-containing emulsion microspheres in super-hydrophobic coating.

Background

Super-hydrophobicity is a special phenomenon of a solid surface and is determined by chemical components of the surface of a coating and a micro-nano structure. The preparation of generally superhydrophobic materials can be achieved by two methods: one is to modify low surface energy substances on the surface of the rough structure, and the other is to build the rough structure on the surface of the hydrophobic material. The surface super-hydrophobic coating has excellent performances of self-cleaning, ice coating prevention, corrosion prevention and the like, and is widely applied to the fields of buildings, electric power facilities, chemical industry, ships and the like in recent years.

The organofluoro compounds are protected from direct damage by tight shielding on the main chain, thereby improving the weatherability, oxidation resistance and corrosion resistance of the organofluoro polymers. Fluorocarbon resins are widely used in the building field, large structures, sea bridges, transportation fields, outdoor signs, and the like, because of their high bond energy due to the fluorocarbon bond, and thus have excellent weather resistance, chemical resistance, insulation properties, and low surface energy. With the increasing environmental protection requirements, water-soluble fluorine coatings are produced and gradually become the focus of research.

The conventional water-based fluorocarbon coating has no self-cleaning function, the stain resistance and the antibacterial property are poor, the contact angle between the surface of the formed coating and water is only 80-100 degrees, the super-hydrophobic effect is difficult to achieve, and the application and development of the fluorocarbon coating are hindered. The Chinese invention patent CN201410139161 discloses a preparation method of a fluorine-containing acrylic acid super-hydrophobic coating, but the coating resin is acrylic resin with fluorine-containing side chains, and the weather resistance is poor. The Chinese invention patent CN201710591868 prepares the fluorine-containing super-hydrophobic coating through polyamide-imide resin, polytetrafluoroethylene emulsion and related auxiliary agents, and adopts polytetrafluoroethylene with fluorine-containing main chain to improve weather resistance, but influences the compatibility and film forming property of the coating resin. The Chinese invention patent CN201610954435.9 adopts silicon dioxide particles treated by fluorine-containing siloxane to mix with aqueous fluorocarbon emulsion resin to prepare the self-cleaning aqueous fluorocarbon coating, but the compatibility of inorganic filler and resin is not good, and the final film-forming performance is influenced. And the controllable range of the particle size of the silicon dioxide particles is small, so that the regulation and control of the micro-nano structure on the surface of the coating are influenced.

Disclosure of Invention

Aiming at the problems in the prior art, the invention provides a method for preparing a super-hydrophobic coating by using core-shell type fluorine-containing emulsion microspheres, aiming at preparing the core-shell type fluorine-containing emulsion microspheres with a structure controllable by polymerizing crosslinked polystyrene serving as a hard core and a softer polystyrene-polybutyl acrylate-polydodecafluoroheptyl polymethacrylate shell through a seed emulsion, and enhancing the hydrophobicity and the antifouling property on the basis of the weather resistance of the traditional fluorocarbon coating and improving the self-cleaning capability of the coating.

The technical scheme adopted by the invention for realizing the purpose is as follows:

the invention provides a preparation method of core-shell type fluorine-containing emulsion microspheres, which comprises the following steps:

(1) firstly, adding an emulsifier, a monomer and deionized water into a reaction bottle, stirring and mixing, heating to 50-80 ℃, adding an initiator, and carrying out heat preservation reaction for 4-6 hours to prepare a seed emulsion;

(2) adding deionized water, an emulsifier, an initiator and a mixed monomer A into the prepared seed emulsion, starting stirring and mixing, heating to 30-50 ℃, preserving heat for 0.5-2 hours, heating to 60-80 ℃ for reaction, starting dropwise adding the mixed monomer B after reacting for 0.5-2 hours, finishing dropwise adding after 1-5 hours, continuing to react for 3-12 hours, and cooling to obtain the core-shell fluorine-containing emulsion microsphere.

Further, in the step (1), the mass ratio of the emulsifier, the monomer, the initiator and the deionized water is (0.2-1): 5-10): 0.005-0.1): 20-50.

Further, in the step (1), the emulsifier is sodium dodecyl sulfate and OP-10, and the mass ratio of the sodium dodecyl sulfate to the OP-10 is (1-3) to 1; the monomer is a mixture of styrene and divinylbenzene, and the mixing mass ratio is (3-10): 1; the initiator is potassium persulfate or ammonium persulfate.

Further, in the step (2), the mass ratio of the deionized water, the emulsifier, the initiator and the mixed monomer is (20-80): 1-0.2): 0.01-0.2): 10-20;

the mixed monomer is the sum of the mixed monomer A and the mixed monomer B.

Further, in the step (2), the emulsifier is a mixture of sodium dodecyl sulfate and OP-10, and the mass ratio of the emulsifier to the emulsifier is (1-0.5): 1; the ratio of the seed emulsion to the water is 1: 2-1: 6; the mixed monomer A is prepared from styrene, butyl acrylate and fluorine-containing acrylate according to the mass ratio of (1-3): (1-4): (0.1-1); the mixed monomer B is prepared from styrene, butyl acrylate and fluorine-containing acrylate according to the mass ratio of (1-3): (1-4): (1-4); the mass ratio of the mixed monomer A to the mixed monomer B is 1 (1-4), and the initiator is potassium persulfate or ammonium persulfate.

Further, the fluorine-containing acrylate is dodecafluoroheptyl methacrylate, dodecafluoroheptyl acrylate, hexafluorobutyl methacrylate, hexafluorobutyl acrylate, tridecafluorooctyl methacrylate or a mixture of two or more monomers.

The invention also provides application of the core-shell type fluorine-containing emulsion microspheres prepared by the preparation method in preparation of the super-hydrophobic weather-resistant coating.

Further, the super-hydrophobic weather-resistant coating is prepared by mixing 5-12 parts of core-shell type fluorine-containing emulsion microspheres, 45-75 parts of aqueous fluorocarbon emulsion, 20 parts of titanium dioxide, 0.5 part of dispersing agent, 0.5 part of defoaming agent, 0.6 part of flatting agent, 0.2-0.4 part of thickening agent and 18 parts of deionized water; the content of the core-shell type fluorine-containing emulsion microspheres in the coating is 3-15 wt%.

Furthermore, the fluorine-containing emulsion microsphere is core-shell structure emulsion taking crosslinked polystyrene as a core and poly (styrene-butyl acrylate-fluorine-containing acrylate) as a shell, the particle size is 40-400 nm, and the fluorine content is 1-10 wt%.

Through detection, the super-hydrophobic weather-resistant coating prepared by the invention has the advantages of high drying speed, 2-4 h of actual drying time, good film forming property of paint, and the contact angle between the formed paint film and water of more than 120 degrees, which is improved by 30-50% compared with the traditional fluorocarbon coating, has better super-hydrophobic property and self-cleaning capability, and simultaneously maintains the good weather resistance of the traditional fluorocarbon coating.

The invention has the beneficial effects that:

(1) the fluorine-containing emulsion microsphere with the core-shell structure prepared by the invention has adjustable particle size, adjustable core-shell hardness and adjustable fluorine content on the surface of the microsphere.

(2) The surface of the fluorine coating prepared by blending the microspheres and the water-based fluorine coating can form a micro-nano coarse structure, and the super-hydrophobicity of the traditional fluorocarbon coating is improved on the basis of keeping the high weather resistance of the fluorocarbon coating. The contact angle between the film-forming surface of the traditional water-based fluorocarbon coating and water is only 80-90 degrees, the particle size and the surface fluorine content of the fluorine-containing emulsion microsphere with the core-shell structure prepared by the invention are adjustable, the soft shell structure endows excellent compatibility, the hard core structure can form a micro-nano-scale rough structure on the surface of the coating obtained after blending with the water-based fluorocarbon coating, the contact angle between the surface of the coating and the water reaches more than 125 degrees through the lotus leaf effect, the self-cleaning capability of the coating is greatly improved, the coating is super-hydrophobic, has the performances of antibiosis, oil resistance, pollution resistance, environmental protection and the like, effectively saves energy consumption, is environment-friendly, and.

Detailed Description

The technical solution of the present invention is further explained and illustrated by the following specific examples.