Light-curing wear-resistant anti-fog coating liquid and preparation method and application thereof

Abstract

The invention discloses a photocurable wear-resistant anti-fog coating liquid and a preparation method and application thereof, belonging to the technical field of greenhouse film preparation. The photocurable wear-resistant anti-fog coating liquid is made of the following raw materials: 59-65 parts of component A, 8.5-13 parts of component B, 1.5-2.5 parts of polyether-modified silicone, 12-15 parts of inorganic nano-sol, 4-6 parts of cosolvent and 1-3 parts of emulsifier. The present invention applies the coating liquid after corona treatment on the greenhouse film, polymerizes polyurethane acrylate, acrylic resin and the like in the form of chemical bonds through intermolecular chemical reactions through ultraviolet light excitation, wraps the effective hydrophilic component inside the coating layer, solves the problem that the effective components in the coating layer are easy to lose, makes the greenhouse film have excellent anti-fog performance, and enhances the wear resistance of the coating layer; the free radicals generated by the greenhouse film after corona treatment combine with the active monomer free radicals in the coating liquid to form a stable chemical bond, thereby increasing the firmness of the combination between the coating layer and the greenhouse film.

Description

Technical Field

[0001] The invention relates to a light-curing wear-resistant anti-fog coating liquid and a preparation method and application thereof, belonging to the technical field of greenhouse film coating layer preparation. Background Art

[0002] With the development of science and technology, agricultural plastic greenhouse films have gradually evolved from long-life films to multifunctional greenhouse films. For example, greenhouse films with anti-fog function can inhibit the formation of fog on the greenhouse film and ensure the light transmittance of the greenhouse film. Especially in the north, the requirements for the greenhouse film's drip and fog removal performance are extremely high.

[0003] The defogging technologies for plastic greenhouse films mainly include the methods of internally adding functional additives and externally applying drip defogging coating liquid. The greenhouse film products that have been widely used before, such as double-protection film, EVA defogging film, grouting film, PE defogging film, PVC film, etc., are all internally added types. The dripping period is only 4-6 months, and the greenhouse film can only be used for 1 year. Both the anti-fog performance and the lifespan of the greenhouse film are limited.

[0004] The emergence of PO film allows greenhouse film to be used for 3-5 years, which greatly promotes resource conservation. Among them, the externally coated polyethylene greenhouse film (PO film), which is coated with a coating liquid with anti-fog and anti-drip functions on the surface of the greenhouse film to form a coating layer, has developed rapidly.

[0005] At present, the coating layer on the greenhouse film is mostly combined with the greenhouse film by physical adsorption. The overall bonding ability and wear resistance of the coating layer on the greenhouse film are limited, and the hydrophilic / hydrophobic components in the coating layer are distributed on the surface of the coating layer, which leads to the rapid failure of the coating layer. In particular, most of the domestic greenhouses are steel frame iron wire greenhouses. The iron wire contacts the inner surface of the greenhouse film. As time goes by, the steel wire easily rubs off the coating layer, resulting in dripping at the part where the coating layer falls off. Crop diseases and rotten flowers and fruits in greenhouses with severe dripping are very serious, and users will also be wetted by dripping water when working in the greenhouse, and the working environment is poor. In addition, there are many horizontal iron wires in domestic steel frame greenhouses (the iron wires are spaced about 20cm apart), and almost all greenhouses in the north are covered with quilts in winter. The squeezing of the quilt will increase the friction between the iron wire and the greenhouse film, aggravating the damage to the coating layer and causing large-scale failure of the greenhouse film.

[0006] For the anti-fog coating produced by the water-based dip coating process, the condensed water in the greenhouse will continuously flush the coating during use, resulting in the loss of surfactants in the coating and causing the problem of hanging drops on the film surface. Especially in the autumn, the greenhouse needs to repeatedly open and close the air vents, and the greenhouse film needs to be repeatedly dried and moistened. Subsequently, large areas of water scales will appear on the film surface, which will greatly affect the light transmittance, causing crop yield reduction and slow growth.

[0007] Therefore, at present, the coating layer of the external anti-fog PO film has a short duration. Due to the friction of the iron wire, the coating layer falls off quickly. The actual service life of most PO films is 1-2 years, which will cause a huge waste of resources for PO films that can withstand aging for up to 5 years.

[0008] In summary, solving the wear resistance problem of the anti-fog coating layer on the basis of ensuring the high anti-fog performance of the greenhouse film is an urgent problem to be solved in the greenhouse planting industry, and it is also an important way for my country to achieve sustainable development of the greenhouse film industry.

[0009] It should be noted that the above contents belong to the technical knowledge of the inventor and do not necessarily constitute prior art. Summary of the invention

[0010] The purpose of the present invention is to solve the problems existing in the prior art and to provide a photocurable wear-resistant anti-fog coating liquid and a preparation method and application thereof, so that the greenhouse film has high defogging performance and good wear resistance.

[0011] The present invention achieves the above-mentioned purpose by adopting the following technical solutions:

[0012] In one aspect, the present invention provides a light-curable wear-resistant anti-fog coating liquid, which is made of the following raw materials in parts by weight:

[0013] 59-65 parts of component A, 8.5-13 parts of component B, 1.5-2.5 parts of polyether-modified silicone, 12-15 parts of inorganic nanosol, 4-6 parts of cosolvent and 1-3 parts of emulsifier;

[0014] The component A is composed of polyurethane acrylate, toughening resin and deionized water in a weight ratio of (18-24):(3-5):(38-40);

[0015] The toughening resin is any one or more of acrylic resin, methacrylic resin or hydroxymethyl acrylic resin; further, the acrylic resin is preferably silane-modified acrylic resin;

[0016] The B component is composed of a reactive diluent, hydroxyethyl acrylate and a photoinitiator in a weight ratio of (8-12):(0.5-1):(1-1.5);

[0017] Optionally, the reactive diluent is any one or more of trimethylolpropane triacrylate, pentaerythritol triacrylate, and 1,6-hexanediol diacrylate;

[0018] Furthermore, the active diluent is preferably a combination of a monofunctional active diluent and a multifunctional active diluent; further, the active diluent is preferably composed of trimethylolpropane triacrylate, pentaerythritol triacrylate, and 1,6-hexanediol diacrylate in a weight ratio of (2-3):(4-6):(2-3).

[0019] Optionally, the polyether-modified silicone is any one or more of BYK333, BYK306, BYK345, WE3220, ED2522, and WE3221.

[0020] Optionally, the inorganic nano sol is composed of alumina sol, silica sol and PEG in a weight ratio of (3-4): (1-2): 3. Alumina sol is a hydrophilic component, silica sol is a hydrophobic component and a thickening agent. The ratio of alumina sol and silica sol can control the hydrophilicity of both sides of the coating layer formed after the coating liquid is cured and can also increase the thickness of the coating layer.

[0021] Optionally, PEG consists of PEG10000, PEG8000, and PEG4000 in a molar ratio of 1:1:1.

[0022] Furthermore, the mass concentration of the aluminum oxide sol is in the range of 20%-30%wt, and the particle size is 80-110nm; the mass concentration of the silicon oxide sol is in the range of 20%-30%wt, and the particle size is 60-90nm.

[0023] Optionally, the co-solvent is dipropylene glycol monomethyl ether or dipropylene glycol monoethyl ether.

[0024] Optionally, the emulsifier is composed of octadecyltrimethylammonium chloride and hexadecyltrimethylammonium chloride in a weight ratio of (6-7):(3-5).

[0025] On the other hand, the present invention also provides a method for preparing the photocurable wear-resistant anti-fog coating liquid, comprising the following steps:

[0026] (1) Mix component A and component B evenly;

[0027] (2) adding polyether modified silicone and mixing evenly;

[0028] (3) adding inorganic nano sol and mixing evenly;

[0029] (4) adding a co-solvent and mixing evenly;

[0030] (5) adding an emulsifier, mixing evenly, and emulsifying at a rotation speed of 3500-4500 r / min for 30-60 min to obtain the light-curable wear-resistant anti-fog coating liquid.

[0031] Specifically, the preparation method of component A is as follows: polyurethane acrylate, toughening resin and deionized water are uniformly mixed to obtain;

[0032] The preparation method of component B is as follows: mix the active diluent and hydroxyethyl acrylate, add the photoinitiator while stirring, and mix well to obtain the component.

[0033] In another aspect, the present invention further provides an application of the photocurable wear-resistant anti-fog coating liquid, wherein the photocurable wear-resistant anti-fog coating liquid is applied to the preparation of greenhouse film, comprising the following steps:

[0034] (1) Corona treatment is performed on the surface of the greenhouse film to make the surface tension of the greenhouse film surface 45-50 dynes;

[0035] (2) uniformly coating the photocurable wear-resistant anti-fog coating liquid on the surface of the greenhouse film after corona treatment with a thickness of 8-10 μm;

[0036] (3) drying the surface of the greenhouse film at 60-75°C to thermally cure the coating liquid to form a thermally cured coating layer;

[0037] (4) Use ultraviolet light with a wavelength of 340-380nm to irradiate the surface of the greenhouse film, so that the thermal curing coating layer is further photocured and formed on the surface of the greenhouse film. During the photocuring process, the greenhouse film is cooled in time to ensure that the temperature of the greenhouse film is not higher than 75°C.

[0038] Furthermore, the photocurable wear-resistant anti-fog coating liquid provided by the present invention is suitable for greenhouse films such as PO film and EVA-PO.

[0039] The beneficial effects of this application include but are not limited to:

[0040] The photocurable wear-resistant anti-fog coating liquid and its preparation method and application provided by the present invention are as follows: the greenhouse film is subjected to corona treatment and then coated with the coating liquid; polyurethane acrylate, acrylic resin and the like in the coating liquid are polymerized into a network structure film in the form of chemical bonds through intermolecular chemical reactions through ultraviolet light excitation to form a coating layer; effective hydrophilic components are wrapped inside the coating layer, which not only ensures the hydrophilicity of the coating layer, but also solves the problem of easy loss of effective components in the coating layer, so that the greenhouse film has excellent anti-fog performance and enhances the wear resistance of the coating layer; and free radicals generated by the greenhouse film after corona treatment can combine with active monomer free radicals in the coating liquid to form stable chemical bonds, thereby increasing the firmness of the combination between the coating layer and the greenhouse film, improving the wear resistance of the coating layer, and improving the weather resistance of the greenhouse film.

[0041] The photocurable wear-resistant anti-fog coating liquid and the coating layer provided by the invention have simple preparation processes and are suitable for mass production. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] The drawings described herein are used to provide a further understanding of the present application and constitute a part of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0043] Figure 1 Schematic diagram of wear resistance testing method;

[0044] Figure 2 This is a schematic diagram of the anti-fog performance test results after wiping the conventional PO film;

[0045] Figure 3 A schematic diagram of the anti-fog performance test results of the greenhouse film prepared by the present invention after being wiped 2-8 times;

[0046] Figure 4 A schematic diagram of the anti-fog performance test results of the greenhouse film prepared in the present invention after being wiped 24-500 times; DETAILED DESCRIPTION

[0047] The present invention will be further described in detail in the following content. However, it should be pointed out that the following specific embodiments only provide specific operation examples of the present invention in an exemplary manner, but the protection scope of the present invention is not limited thereto. The protection scope of the present invention is limited only by the claims. It is obvious to those skilled in the art that various other improvements and replacements can be made to the embodiments of the present invention within the protection scope defined by the claims of the present invention, and the same technical effects can still be achieved, thereby achieving the ultimate technical purpose of the present invention.

[0048] Unless otherwise specified, all raw materials in this manual were purchased through commercial channels. The specific purchasing manufacturers of some raw materials are described as follows.

[0049] Polyurethane acrylic resin (McLean), acrylic resin (Jinrunna 8109), trimethylolpropane triacrylate (McLean), pentaerythritol triacrylate (Aladdin), 1,6-hexanediol diacrylate (McLean), hydroxyethyl acrylate (McLean), polyethylene glycol (McLean), dipropylene glycol monomethyl ether (Aladdin), octadecyltrimethylammonium chloride (Hongjiang Reagent), hexadecyltrimethylammonium chloride (Hongjiang Reagent), TPO-L (Lan Kelu).

[0050] The photocurable wear-resistant anti-fog coating liquid provided by the present invention and its preparation method and application are described in detail below through specific embodiments.

[0051] Embodiment 1:

[0052] The raw materials used in the photocurable wear-resistant anti-fog coating liquid provided in this embodiment are shown in Table 1.

[0053] Table 1

[0054]

[0055] The production method of the coating liquid provided in Example 1 is:

[0056] (1) At room temperature, weigh polyurethane acrylate and acrylic resin, mix them, and add deionized water to dilute them evenly to prepare component A;

[0057] Weigh trimethylolpropane triacrylate, pentaerythritol triacrylate, 1,6-hexanediol diacrylate and hydroxyethyl acrylate, mix, and add photoinitiator TPO-L during stirring to obtain component B;

[0058] Mix component A and component B evenly;

[0059] (2) Weigh polyether modified silicone BYK333, add it into the system, and stir to mix evenly;

[0060] (3) Weigh alumina sol, silica sol and PEG, stir for half an hour to fully dissolve them, then add them into the system and mix them evenly with the components in the system;

[0061] (4) Weigh dipropylene glycol monomethyl ether and add it to the system, stir at a speed of 300-500 r / min for 10-15 minutes to mix evenly;

[0062] (5) Weigh octadecyltrimethylammonium chloride and hexadecyltrimethylammonium chloride, mix them evenly, and add them into the system. After stirring for 10-15 minutes, the speed of the emulsifier is 4000 r / min, and the emulsification is performed for 30 minutes to obtain a light-curable wear-resistant and anti-fog coating liquid.

[0063] Embodiment 2:

[0064] The raw materials used in the photocurable wear-resistant anti-fog coating liquid provided in this embodiment are shown in Table 2.

[0065] Table 2

[0066]

[0067] Embodiment 3:

[0068] The raw materials used in the photocurable wear-resistant anti-fog coating liquid provided in this embodiment are shown in Table 3.

[0069] Table 3

[0070]

[0071]

[0072] The production method of the coating liquid provided in Example 2-3 is:

[0073] (1) At room temperature, polyurethane acrylate, toughening resin and deionized water are uniformly mixed to prepare component A;

[0074] Mix the active diluent and hydroxyethyl acrylate, add the photoinitiator TPO-L while stirring, and mix well to prepare component B;

[0075] Mix component A and component B evenly;

[0076] (2) adding polyether modified silicone and stirring to mix evenly;

[0077] (3) adding the uniformly mixed inorganic nano-sol and continuing to stir and mix uniformly;

[0078] (4) adding a co-solvent, stirring at a speed of 300-500 r / min for 10-15 minutes to mix evenly;

[0079] (5) adding the mixed emulsifier, continuing to stir and mix evenly, and emulsifying at a speed of 3500-4000 r / min for 50 minutes to obtain the light-curable wear-resistant anti-fog coating liquid.

[0080] The method for applying the coating liquid provided in Examples 1-3 on the greenhouse film is as follows:

[0081] (1) Corona treatment is performed on the surface of the greenhouse film to make the surface tension of the greenhouse film reach 48 dynes;

[0082] (2) applying a light-curable wear-resistant anti-fog coating liquid evenly on the surface of the greenhouse film after the corona treatment with a thickness of 8-10 μm;

[0083] (3) drying the surface of the greenhouse film at 60-75°C to thermally cure the coating liquid to form a thermally cured coating layer;

[0084] (4) Use ultraviolet light with a wavelength of 365nm to irradiate the surface of the greenhouse film, so that the thermal curing coating layer is further photocured and formed on the surface of the greenhouse film. During the photocuring process, the greenhouse film is cooled in time to ensure that the temperature of the greenhouse film is not higher than 75°C.

[0085] Among them, the greenhouse film is PO film or EVA-PO film.

[0086] The light transmittance, anti-fog performance and abrasion resistance test of the coating liquid provided by the present invention when applied to greenhouse film:

[0087] The coating liquid prepared in each embodiment and comparative example was applied to a PO film with a thickness of 0.07-0.16 mm according to the method provided by the present invention to prepare a greenhouse film sample. The anti-fog performance and abrasion resistance of the greenhouse film were tested in a laboratory environment. See Table 4.

[0088] Light transmittance detection method: Use a transmittance haze meter for detection.

[0089] Anti-fog performance testing method: Use a drip test machine to observe and record the duration of the water film mirror on one side of the coating layer at 80℃ and 40℃ and high humidity conditions.

[0090] Wear resistance: Figure 1 As shown in the figure, under laboratory conditions, the sponge was pressed to the bottom to wipe the coating layer of the greenhouse film under water flow, and the defogging effect of the greenhouse film was observed at 60°C, and the number of friction failures was recorded. Among them, the number of failures after friction is the number of times the coating layer completely failed after friction.

[0091] Table 4

[0092]

[0093] The mirror surface of the greenhouse film measured under laboratory conditions at 60°C lasts for 10 days, which is equivalent to more than 5 years under actual outdoor use conditions. As shown in Table 4, the greenhouse film made by the coating liquid provided by the present invention has excellent anti-fog performance.

[0094] In addition, the applicant of the present invention also compared the anti-fog performance of the greenhouse film prepared by the coating liquid provided by the present invention with that of the ordinary PO film. The results are as follows: Figure 2-Figure 4 Observation Figure 2 It can be seen that the conventional PO membrane began to fail after being wiped twice by sponge under water flow. Figure 3 It can be seen that there is no change after the greenhouse film provided by the present invention is wiped 8 times. Figure 4 It can be seen that the greenhouse film provided by the present application has slight marks after being wiped 200 times, and hanging drops appear in a very small area after being wiped 500 times, but it is not ineffective.

[0095] Comparative Example 1:

[0096] In order to explore the effect of photocuring agent on the performance of the coating layer, the applicant of the present invention changed the type and amount of photoinitiator on the basis of Example 1, designed Comparative Examples 1-1, 1-2, 1-3 and 1-4, and used the same preparation method to prepare the coating liquid or further coated the coating liquid on a greenhouse film with a thickness of 0.07-0.16 mm for experiments. The results are shown in Table 5 below.

[0097] Specifically, the applicant of the present invention applied the coating liquid provided by Comparative Example 1-1, Comparative Example 1-3, and Comparative Example 1-4 on a PO film with a thickness of 0.1 mm to make a greenhouse film sample, and observed the usage of the coating layer on the greenhouse film; the coating liquid provided by Comparative Example 1-2, Example 1, and Example 2 was stored in the dark at the same room temperature, and the state changes of the coating liquid were observed.

[0098] Table 5

[0099]

[0100] It can be seen that the coating liquid obtained by using the photocuring agent TPO-L selected in the present application has good stability, and the coating layer obtained when applied to the greenhouse film has appropriate hardness and good wear resistance.

[0101] Comparative Example 2:

[0102] In order to explore the effect of emulsifier on the performance of the coating layer, the applicant of the present invention changed the type and amount of emulsifier on the basis of Example 1, designed Comparative Example 2-1, Comparative Example 2-2, Comparative Example 2-3, Comparative Example 2-4, Comparative Example 2-5, and Comparative Example 2-6, and adopted the same preparation method to make coating liquids for experiments. The results are shown in Table 6 below.

[0103] Specifically, the applicant of the present invention stored the coating liquids provided in the comparative examples and embodiments in Table 6 at the same room temperature in the dark, and observed the state changes of the coating liquids.

[0104] Table 6

[0105]

[0106] It can be seen that the coating liquid obtained by using the emulsifier selected in the present application has a long storage time and good stability.

[0107] Comparative Example 3:

[0108] In order to explore the effect of PEG on the performance of the coating layer, the applicant of the present invention changed the molecular weight and dosage of PEG on the basis of Example 1, designed Comparative Example 3-1, Comparative Example 3-2, Comparative Example 3-3, Comparative Example 3-4, Comparative Example 3-5, and Comparative Example 3-6, and adopted the same preparation method to make the coating liquid, which was applied to a PO membrane with a thickness of 0.1 mm for experiment. The results are shown in Table 7 below.

[0109] Table 7

[0110]

[0111] It can be seen that the coating layer obtained by the PEG molecular weight and ratio selected in the present application has good film-forming speed and wear-resistant effect.

[0112] The above specific implementation manner cannot be used as a limitation on the protection scope of the present invention. For those skilled in the art, any substitution, improvement or change made to the implementation manner of the present invention falls within the protection scope of the present invention.

[0113] The matters not described in detail in the present invention are all known technologies to those skilled in the art.

Claims

1. A light-curing wear-resistant anti-fog coating liquid, characterized in that: Made from the following raw materials in parts by weight: 59-65 parts of component A, 8.5-13 parts of component B, 1.5-2.5 parts of polyether-modified silicone, 12-15 parts of inorganic nanosol, 4-6 parts of cosolvent and 1-3 parts of emulsifier; The component A is composed of polyurethane acrylate, toughening resin and deionized water in a weight ratio of (18-24):(3-5):(38-40); The toughening resin is any one or more of acrylic resin, methacrylic resin or hydroxymethyl acrylic resin; The B component is composed of a reactive diluent, hydroxyethyl acrylate and a photoinitiator TPO-L in a weight ratio of (8-12):(0.5-1):(1-1.5); The active diluent is composed of trimethylolpropane triacrylate, pentaerythritol triacrylate and 1,6-hexanediol diacrylate in a weight ratio of (2-3):(4-6):(2-3); The inorganic nano sol is composed of alumina sol, silica sol and PEG in a weight ratio of (3-4):(1-2):3, and PEG is composed of PEG10000, PEG8000 and PEG4000 in a molar ratio of 1:1:1; The cosolvent is dipropylene glycol monomethyl ether or dipropylene glycol monoethyl ether; The emulsifier is composed of octadecyltrimethylammonium chloride and hexadecyltrimethylammonium chloride in a weight ratio of (6-7):(3-5); The method for preparing the light-curable wear-resistant anti-fog coating liquid comprises the following steps: (1) Mix component A and component B evenly; (2) adding polyether modified silicone and mixing evenly; (3) adding inorganic nano sol and mixing evenly; (4) adding a co-solvent and mixing evenly; (5) adding an emulsifier, mixing evenly, and emulsifying at a rotation speed of 3500-4500 r / min for 30-60 min to obtain the light-curable wear-resistant anti-fog coating liquid.

2. The light-curable wear-resistant anti-fog coating liquid according to claim 1, characterized in that: The acrylic resin is silane-modified acrylic resin.

3. The light-curable wear-resistant anti-fog coating liquid according to claim 1, characterized in that: The polyether-modified silicone is any one or more of BYK333, BYK306, BYK345, WE3220, ED2522, and WE3221.

4. The light-curable wear-resistant anti-fog coating liquid according to claim 1, characterized in that: The mass concentration range of the aluminum oxide sol is 20%-30%wt, and the particle size is 80-110nm; the mass concentration range of the silicon oxide sol is 20%-30%wt, and the particle size is 60-90nm.

5. The light-curable wear-resistant anti-fog coating liquid according to claim 1, characterized in that: The preparation method of component A is as follows: polyurethane acrylate, toughening resin and deionized water are uniformly mixed to obtain; The preparation method of component B is as follows: mix the active diluent and hydroxyethyl acrylate, add the photoinitiator while stirring, and mix well to obtain the component.

6. The use of the photocurable wear-resistant anti-fog coating liquid according to claim 1, characterized in that: The light-curable wear-resistant anti-fog coating liquid is applied to the preparation of greenhouse film, comprising the following steps: (1) Corona treatment is performed on the surface of the greenhouse film to make the surface tension of the greenhouse film surface 45-50 dynes; (2) uniformly coating the photocurable wear-resistant anti-fog coating liquid on the surface of the greenhouse film after the corona treatment with a thickness of 8-10 μm; (3) drying the surface of the greenhouse film at 60-75°C to thermally cure the coating liquid to form a thermally cured coating layer; (4) Use ultraviolet light with a wavelength of 340-380nm to irradiate the surface of the greenhouse film, so that the thermal curing coating layer is further photocured and formed on the surface of the greenhouse film. During the photocuring process, the greenhouse film is cooled in time to ensure that the temperature of the greenhouse film is not higher than 75°C.

7. The use of the photocurable wear-resistant anti-fog coating liquid according to claim 6, characterized in that: The greenhouse film is a PO film or an EVA-PO film.

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