CN106752857A - A kind of preparation method of the super hydrophilic antifogging coating of dual cure acrylate - Google Patents

Abstract

The object of the present invention is to provide a kind of preparation method of dual curing acrylate superhydrophilic anti-fog coating. The present invention uses acrylate monomers as main raw materials, adopts free radical polymerization to introduce silane coupling agent, hydroxyethyl acrylate and sulfoacrylamide monomers, and then uses semi-blocked polyurethane to react with hydroxyl groups in the main chain to introduce double bonds . Among them, the sulfonic acid group on the main chain can endow the coating with good hydrophilicity; the silane coupling agent can hydrolyze and cure the coating with tetraethyl orthosilicate, and the uncondensed silanol can further improve the hydrophilicity of the coating. Give the coating film good anti-fog performance; the introduction of double bonds realizes the photocuring of acrylate. After the resin system is cured into a film, it can not only ensure excellent adhesion, water resistance, hardness and high transparency, but also have excellent hydrophilicity, and have a good anti-fog effect on transparent substrates.

Description

A kind of preparation method of dual curing acrylate superhydrophilic anti-fog coating

technical field

The invention belongs to the technical field of polymer materials, and in particular relates to a preparation method of a dual-curing acrylate superhydrophilic anti-fog coating.

background introduction

Transparent substrates (such as glass) are indispensable materials in our daily life and production, but they are prone to fogging during use, resulting in reduced light transmittance and reflectivity on the surface of the material, affecting sightlines, and affecting our lives. Bring a lot of inconvenience, even can cause serious harm. At present, there are two main anti-fog methods: electrothermal method and coating anti-fog method. Compared with the electrothermal method, the anti-fog coating has more extensive application prospects because of its convenient use, no energy consumption after coating, simple production process, low equipment cost, and low investment; and the common principles of anti-fog coatings are generally divided into superhydrophobic There are many reports on the use of resins to achieve hydrophobicity. Venkateswara et al. used methyltrimethoxysilane as a raw material to prepare a superhydrophobic film with a contact angle of 173°, but the real application is still difficult to achieve. The main performance In terms of poor adhesion and low hardness. Superhydrophilicity has attracted more people's attention because it is relatively easier to achieve. The research group of Professor Rubner of the Massachusetts Institute of Technology adopted a layered self-assembly method to alternately deposit 7nm SiO ₂ nanoparticles and polyelectrolyte on the glass surface to form a contact angle of less than 5. ° superhydrophilic porous film. However, due to the complex preparation process and difficult coating process of most inorganic nanoparticles, most of them need to be sintered, which makes their application environment very limited; later, researchers thought of using pure resin to prepare anti-fog coatings, such as Zoromba, etc. developed a performance Excellent UV-curable urethane acrylate anti-fog coatings, but most pure resins are difficult to achieve a balance between hydrophilicity and water resistance. The report of using organic-inorganic hybridization to prepare superhydrophilic has become a research hotspot.

This design uses 3-(trimethoxysilyl)propyl-2-methyl-2-acrylate (MPS) silane coupling agent modified acrylic resin as the main chain, and introduces the hydrophilic monomer 2-acrylamide - 2-Methylpropanesulfonic acid (AMPS), innovatively adopts tetraethyl orthosilicate (TEOS) as a new curing agent, and the hydroxyl group produced by hydrolysis of silane coupling agent (MPS) shrinks and cures; at the same time, it uses half-capped Polyurethane introduces double bonds in the main chain to realize photocuring, which improves the curing speed. This design also uses orthoethyl silicate (TEOS) to introduce a large number of hydroxyl groups and utilizes the low surface tension of the Si-O-Si bond to bring the hydroxyl groups to the surface of the coating. The layer has excellent hardness and water resistance, which overcomes the shortcomings of traditional super-hydrophilic anti-fog coatings such as low reuse rate, poor water resistance, low transparency, and poor anti-fog effect.

Contents of the invention

The object of the present invention is to provide a kind of preparation method of dual curing acrylate superhydrophilic anti-fog coating. The present invention uses acrylate monomers as main raw materials, adopts free radical polymerization to introduce silane coupling agent, hydroxyethyl acrylate and sulfoacrylamide monomers, and then uses semi-blocked polyurethane to react with hydroxyl groups in the main chain to introduce double bonds . Among them, the sulfonic acid group on the main chain can endow the coating with good hydrophilicity; the silane coupling agent can hydrolyze and cure the coating with tetraethyl orthosilicate, and the uncondensed silanol can further improve the hydrophilicity of the coating. Give the coating film good anti-fog performance; the introduction of double bonds realizes the photocuring of acrylate. After the resin system is cured into a film, it can not only ensure excellent adhesion, water resistance, hardness and high transparency, but also have excellent hydrophilicity, and have a good anti-fog effect on transparent substrates.

Technical scheme of the present invention is:

A preparation method of thermosetting polyacrylate hydrophilic anti-fog coating, comprising the steps of:

(1) Preparation of modified acrylic resin prepolymer: measure acrylic acid (AA), 2-acrylamide-2-methylpropanesulfonic acid (AMPS), functional acrylic monomer, silane coupling agent, N,N Dimethylformamide (DMF) was added into a dry four-necked flask equipped with a stirrer, a condenser, a nitrogen conduit and a constant pressure dropping funnel (the AA was subjected to column treatment in advance to remove the polymerization inhibitor) and stirred evenly at room temperature, and passed into Under nitrogen protection, gradually raise the temperature to 80°C; weigh and measure the initiator, dissolve it in a small amount of DMF, use a constant pressure dropping funnel to control the dropping speed to 2 seconds/drop, add about half of the initiator, react for 4 hours, and then dissolve the remaining part with After adding all the same dropping speed into the system and reacting for 3 hours, it is counted as PAAMH and set aside.

(2) Preparation of polyurethane-modified acrylic resin: Add metered isophorone diisocyanate (IPDI), hydroxyethyl acrylate (HEA), acetone (ACE), and catalyst into a drying oven equipped with agitator, condenser tube, and nitrogen conduit. In the three-necked flask, stir evenly at room temperature, pass through nitrogen protection, and gradually raise the temperature to 55°C; at the same time, weigh and measure tetramethoxyphenol (MEHQ) dissolved in a small amount of acetone (ACE), quickly drop into the system, and react for 2 hours. After the free -NCO value in the system was titrated by the di-n-butylamine method, the system was cooled to room temperature, the product was transferred to a constant pressure dropping funnel, and added dropwise to the first step product PAAMH at a dropping speed of 2 seconds/drop. In the process, add catalyst, add a small amount of methanol after the free -NCO content in the titration system reaches the theory, and the remaining -NCO is completely reacted, and the characteristic absorption peak of -NCO at 2270 cm ^-1 is detected by infrared spectrometer and disappears completely, and finally the The product was removed with a rotary evaporator to remove a small amount of acetone in the system to obtain a dual-cured super-hydrophilic anti-fog resin, which was designated as PAAMH-IH.

(3) Preparation of cured film: take a certain amount of PAAMH-IH, add polymer quality 3% photoinitiator Irgacure1173, 0.3% leveling agent 3288, a certain amount of tetraethyl orthosilicate (TEOS), account for 25% trimethylolpropane triacrylate (TMPTA) and ethanol in the resin system, then adjust the pH of the sample to about 13 with 25% ammonia water, and after stirring evenly at room temperature in the dark, quickly coat the resin on a clean glass slide Chip. Bake at 45°C in the dark for 2 hours, then adjust the oven temperature to 75°C and bake for 2 hours, and finally put it into a 1.5kw portable UV curing machine for 35-40s.

The functional acrylic monomer described in step (1) is at least one of hydroxyethyl acrylate (HEA) and hydroxyethyl methacrylate (HEMA);

Initiator described in step (1) is at least one in azobisisobutyronitrile (AIBN), dibenzoyl peroxide (BPO);

The silane coupling agent described in step (1) is 3-(trimethoxysilyl)propyl-2-methyl-2-acrylate (MPS), γ-methacryloxypropyltrimethoxy At least one of base silane (KH-570);

Catalyst described in step (2) is at least one in dibutyltin dilaurate, stannous octoate;

The beneficial effects of the present invention are: through the above reaction, the poly-modified acrylate resin with water resistance, scratch resistance and strong mechanical properties can be synthesized by thermal-light dual curing. After the resin is cured into a film, it can be used on the surface requiring anti-fog.

detailed description

The following examples are used to describe the solutions of the present invention in more detail, but the present invention is not limited to the solutions described in the examples.

Example 1

(1) Preparation of modified acrylic resin prepolymer: 10.00g acrylic acid (AA), 3.09g 2-acrylamide-2-methylpropanesulfonic acid (AMPS), 6.00g hydroxyethyl acrylate (HEA), 2.00g3 -(trimethoxysilyl)propyl-2-methyl-2-acrylate (MPS), 50mL N,N dimethylformamide (DMF) were added to the In the dry four-neck bottle of the dropping funnel (the AA and HEA were subjected to column treatment in advance to remove the polymerization inhibitor), stir evenly at room temperature, pass through nitrogen protection, and gradually heat up to 80 ° C; weigh 0.30 g of azobisisobutyronitrile ( AIBN), dissolved in a small amount of 5mL DMF, using a constant pressure dropping funnel to control the dropping rate to 2 seconds/drop, add about half of the initiator, react for 4 hours, and then add the remaining part to the system at the same dropping rate and react for 3 hours. , denoted as PAAMH, spare.

(2) Preparation of polyurethane-modified acrylic resin: 11.50g isophorone diisocyanate (IPDI), 6.00g hydroxyethyl acrylate (HEA), 50mL acetone (ACE), 0.01g dibutyltin dilaurate (DBTDL) Add it into a dry three-necked flask equipped with a stirrer, a condenser, and a nitrogen conduit, stir evenly at room temperature, pass through nitrogen protection, and gradually raise the temperature to 55°C; at the same time, weigh 0.05g of tetramethoxyphenol (MEHQ) and dissolve it in 5mL of acetone ( ACE), quickly added dropwise to the system, and reacted for 2h. After the free -NCO value in the system was titrated by the di-n-butylamine method, the system was cooled to room temperature, the product was transferred to a constant pressure dropping funnel, and added dropwise to the first step product PAAMH at a dropping speed of 2 seconds/drop. In the process, add catalyst 0.06gDBTDL, add a small amount of methanol after the content of free -NCO in the titration system reaches the theory, the remaining -NCO is completely reacted, and the characteristic absorption peak of -NCO at 2270cm ^-1 is detected by infrared spectrometer and disappears completely. Finally, use a rotary evaporator to remove a small amount of acetone in the system to obtain a dual-cured superhydrophilic anti-fog resin, which is designated as PAAMH-IH.

(3) Preparation of cured film: Weigh 1.00g of PAAMH-IH, add 0.05g (5% of polymer mass) photoinitiator Irgacure1173, 0.01g leveling agent 3288, 0.20g tetraethyl orthosilicate (TEOS) , 0.02g trimethylolpropane triacrylate (TMPTA) and 30mL ethanol, then adjust the pH of the sample to about 13 with 25% ammonia water, stir evenly at room temperature in the dark, and quickly coat the resin on a clean glass slide . Bake at 45°C in the dark for 2 hours, then adjust the oven temperature to 75°C and bake for 2 hours, and finally put it into a 1.5kw portable UV curing machine for 35-40s.

Claims (1)

1. a kind of preparation method of the super hydrophilic antifogging coating of dual cure acrylate, its characterization step is：

(1) preparation of acrylic resin modified performed polymer：Will metering acrylic acid (AA), 2- acrylamide-2-methyl propane sulfonics (AMPS), feature acrylic monomers, silane coupler, N, N-dimethylformamide (DMF) add equipped with agitator, condenser pipe, Drying for nitrogen conduit and constant pressure funnel (carried out post treatment to AA in advance and remove polymerization inhibitor) to be stirred at room temperature in four-hole bottle Uniformly, nitrogen protection is passed through, 80 DEG C are progressively warming up to；Metering initiator is weighed, is dissolved in a small amount of DMF, use constant pressure funnel It is 2 seconds/drop to control drop speed, adds about half initiator, reacts 4h, after remaining part is all added to system with identical drop speed In react 3h again after, be counted as PAAMH, it is standby；

(2) preparation of polyurethane modified acrylic resin：Will metering IPDI (IPDI), hydroxy-ethyl acrylate (HEA), acetone (ACE), catalyst are added and dry there-necked flask equipped with agitator, condenser pipe, nitrogen conduit, are stirred at room temperature It is even, nitrogen protection is passed through, progressively it is warming up to 55 DEG C；Metering tetramethoxy phenol (MEHQ) is weighed simultaneously is dissolved in a small amount of acetone (ACE), Fast drop reacts 2h in system；Using in di-n-butylamine method titration system dissociate-nco value after, system is cooled to room Temperature, constant pressure funnel is transferred to by product, and is added dropwise in first step product PAAMH with the drop speed of 2 seconds/drop, is added Catalyst, dissociate in continuous titration system-NCO content adds a small amount of methyl alcohol after reaching theory, by remaining-NCO reactions Completely, 2270cm is detected with infrared spectrometer^-1The characteristic absorption peak for locating-NCO is wholly absent, finally by product Rotary Evaporators A small amount of acetone in removing system, obtains final product the super hydrophilic antifog resin of dual cure, is counted as PAAMH-IH；

(3) preparation of cured film：A certain amount of PAAMH-IH is weighed, the light trigger of polymer quality 3% is added Irgacure1173,0.3% levelling agent 3288, a certain amount of tetraethyl orthosilicate (TEOS), three hydroxyls that account for resin system 25% Propane tri (TMPTA) and ethanol, then adjust sample pH value=13 or so, lucifuge with the ammoniacal liquor that concentration is 25% After being stirred at room temperature uniformly, resin is coated in clean glass slide rapidly；45 DEG C of lucifuges toast 2h, then oven temperature is adjusted into 75 DEG C baking 2h, finally puts it into and solidifies 35~40s in the portable UV curing of 1.5kw；

Feature acrylic monomers described in step (1) is in hydroxy-ethyl acrylate (HEA), hydroxyethyl methacrylate (HEMA) At least one；

Initiator described in step (1) is at least one in azodiisobutyronitrile (AIBN), dibenzoyl peroxide (BPO)；

Silane coupler described in step (1) be 3- (trimethoxysilyl) propyl group -2- methyl -2- acrylate (MPS), At least one in γ-methacryloxypropyl trimethoxy silane (KH-570)；

Catalyst described in step (2) is at least one in dibutyl tin laurate, stannous octoate.