CN115403949A

CN115403949A - Normal-temperature curing type water-based coating composition and preparation method of coating liquid

Info

Publication number: CN115403949A
Application number: CN202210225364.4A
Authority: CN
Inventors: 邬浩凯; 韩超
Original assignee: Ningbo Yong'an Guangke New Material Technology Co ltd
Current assignee: Ningbo Yong'an Guangke New Material Technology Co ltd
Priority date: 2022-03-09
Filing date: 2022-03-09
Publication date: 2022-11-29

Abstract

The invention discloses a normal temperature curing type water-based paint composition, which comprises the following components: a hydrolytic condensate of silicate, wherein the silicate comprises one or more of sodium silicate, lithium silicate, potassium silicate and potassium lithium silicate, and the modulus is 2.5-5; the mass ratio of the silicate to the hollow silica nanospheres is 8; the mass ratio of the film-forming additive to the silicate is 0.001-0.2; the mass ratio of the filler to the silicate is 0.5-1.5, the silicate metal salt hydrolytic condensation product is matched with the hollow nanospheres, the film forming additive, the filler and the like, the mixture is diluted by a solvent and then coated, the coating can be cured to form a film layer at normal temperature, and the hardness, weather resistance, self-cleaning, antireflection, cementation and other properties of the film layer are greatly improved, so that the coating is particularly suitable for being applied to glass photovoltaic modules.

Description

Normal-temperature curing type water-based coating composition and preparation method of coating liquid

Technical Field

The invention relates to the technical field of optical materials, in particular to a normal-temperature curing type water-based coating composition and a preparation method of a coating liquid.

Background

When a beam of light passes from one species into another, reflection occurs at the interface. In many fields, the reflection needs to be eliminated, for example, in the fields of solar photovoltaic photo-thermal and agricultural greenhouses, the reflection reduction can bring higher sunlight utilization rate, and in the fields of display and showcase glass, the reflection reduction can bring more real color restoration. By introducing an antireflective coating of suitable refractive index at the interface, reflection can be effectively reduced.

The photovoltaic glass antireflection film is a protective film layer with antireflection and antireflection effects, which is coated on the surface of cover plate glass (photovoltaic glass) in a photovoltaic module. The solar cell cover plate glass can effectively improve the transmittance of sunlight on the photovoltaic cover plate glass, so that the power generation efficiency of the solar cell is improved. Cover glass in solar photovoltaic modules was assembled in an uncoated form without inventing an effective photovoltaic glass antireflective coating, and statistically, the installed capacity of the globally uncoated module between 2008 and 2017 exceeded 300GW, indicating over 1 x 10 ⁹ The bulk photovoltaic module has no antireflective coating, resulting in inefficient use of about 12GW of power. And the anti-reflecting film plated in the early stage has poor weather resistance, and has the phenomena of scratch, shedding, internal structure corrosion collapse and the like, and the anti-reflecting film is easy to accumulate ash layers on the surface when being used outdoors, so that the generated energy of the photovoltaic module is reduced.

The existing antireflection coating liquid on the market can only show the antireflection performance by removing a template agent at high temperature, so that the existing antireflection coating liquid is mostly only suitable for being used by a photovoltaic glass factory in cooperation with a toughening furnace for coating, and is difficult to be directly coated and constructed on an established photovoltaic power station. In addition, the conventional photovoltaic module is packaged by glass, so that the large-size glass photovoltaic module is inconvenient to transport and has strict requirements on the installation environment. Therefore, a light photovoltaic component is produced, the component is packaged by adopting special fiber cloth, the packaging material is not resistant to high temperature, most of the existing photovoltaic antireflection coating liquid contains a template agent, the template agent needs to be solidified at high temperature, and an antireflection coating liquid cannot be formed at normal temperature, so that improvement is needed.

Disclosure of Invention

In order to solve at least one technical defect, the invention provides the following technical scheme:

the present document discloses a normal temperature curable water-based paint composition comprising:

a hydrolytic condensate of silicate, wherein the silicate comprises one or more of sodium silicate, lithium silicate, potassium silicate and potassium lithium silicate, and the modulus is 2.5-5;

the mass ratio of the silicate to the hollow silica nanospheres is 8;

the mass ratio of the film-forming additive to the silicate is 0.001-0.2;

the mass ratio of the filler to the silicate is 0.5-1.5.

According to the scheme, the silicate metal salt hydrolytic condensation compound is matched with the hollow nanospheres, the film forming additive, the filler and the like, the coating is carried out after the dilution with the solvent, the coating can be cured into the film layer at normal temperature, the hardness, the weather resistance, the self-cleaning, the antireflection, the cementation and other properties of the film layer are greatly improved, and the glass photovoltaic module is particularly suitable for being applied to glass photovoltaic modules.

The compounding mechanism of the coating composition is as follows: after being diluted by a solvent, a silicate hydrolysis condensation compound forms a net structure under the action of a film forming additive, a filler supplements gaps of the net structure, the hollow silicon dioxide nanospheres improve the emission reduction performance, and a film liquid formed by matching the components can be solidified and formed at normal temperature, so that the coating, the use and the like are more convenient.

Furthermore, the hollow silicon dioxide nanospheres have the particle size of 10-80nm, the wall thickness of 3-20nm, preferably 25-75nm and the wall thickness of 4-15nm, and are beneficial to improving the performance of the membrane layer.

Further, the types of the film-forming additives are more, and after a large number of attempts and tests, the performance of the film layer can be better improved by the alcohol ether film-forming additives, and therefore, the following steps are preferred:

the film forming assistant is alcohol ether, and comprises one or more of propylene glycol methyl ether, propylene glycol ethyl ether, propylene glycol butyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monopropyl ether, dipropylene glycol tert-butyl ether, dipropylene glycol monobutyl ether and tripropylene glycol n-butyl ether propylene glycol phenyl ether.

Furthermore, the filler is solid silica spheres or silica aerogel, and the particle size is 3-15nm, preferably 5-10nm.

Preferably, the hydrolytic condensate of the silicate, i.e., a reactant formed by mixing the silicate with water and reacting the mixture by hydrolysis, condensation, or the like, can be prepared by a sol-gel method, for example, by mixing the silicate with water at room temperature.

Further, the solvent is a mixture of water and lower alcohol, wherein the water accounts for 75-90% by mass. For lower alcohols, one or more of methanol, ethanol, isopropanol, and n-propanol may be mentioned.

Further, the paint also comprises a solvent, the mass ratio of the solvent to the silicate is 30-110, and the solvent plays a role in dilution.

The application discloses a preparation method of a normal-temperature curing type water-based coating liquid, which comprises the following steps of mixing silicate, partial solvent and hollow silica nanospheres to form a solution A;

mixing the film forming assistant, the filler and the residual solvent to form a solution B;

and mixing the solution A and the solution B to form coating liquid.

The forming mode is helpful for stably combining the nanospheres in the sol solution of the silicate and improving the distribution uniformity, and is helpful for improving the consistent type of the antireflection performance of each part of the film layer, and the mode of premixing in batches and mixing helps to improve the uniformity of material distribution, and the performance of the film layer is improved.

Of course, the raw materials required for preparing the hydrolytic condensation product can be directly and integrally mixed with the hollow silica nanospheres, the filler and the like to form the membrane liquid according to the needs.

When the solutions A and B are prepared, the components are promoted to be rapidly mixed in a continuous stirring mode, such as stirring for 30min, 1h, 2h, 3h and longer, and the materials can be promoted to be rapidly mixed at normal temperature or increased temperature.

In addition, the proportion of the solvent in the solution A and the solution B can be changed according to needs, such as 3/5 of the total solvent is added in the step 2, 4/5 can be used, and the solid content of the silicate in the total solution is preferably 1-2.5%.

Preferably, in the step of forming the coating liquid B, the components are uniformly stirred at the temperature of 30-60 ℃ to be helpful for quickly and uniformly mixing the components.

Further, the solution A and the solution B are mixed uniformly and aged for at least 24h, and then the mixture can be coated on a substrate and can be cured into a film at normal temperature.

The silicate solution is subjected to reactions such as hydrolytic polycondensation and the like without interruption, namely the 'aging' phenomenon, the newly prepared coating solution is aged for different time, the coating solution is changed in bonding strength, and the aging time can be carried out according to the requirement, for example, after the solutions A and B are mixed, the solution is aged for at least 24 hours at normal temperature to form a final coating solution which can be directly coated.

The test shows that the aging time is 1-5 days, the photovoltaic product has the advantages of high bonding strength, balanced performance of the film layer and the like, and the aging time can be increased or reduced according to the requirement, or the solution A and the solution B can be directly used after being uniformly mixed.

The thickness of the coating is preferably 40 to 300nm, more preferably 50 to 150nm.

The substrate is one of photovoltaic glass, ultra-white glass, common float glass and flexible photovoltaic substrates, and is more preferably photovoltaic glass and light flexible photovoltaic substrates. The coating mode can be as follows: and the coating is one of roll coating, spray coating, blade coating, spin coating and dip coating, and more preferably one of roll coating, spray coating and blade coating.

Compared with the prior art, the invention has the beneficial effects that:

1. the coating components of the film coating liquid, the preparation method and the like are improved, the film can be cured and formed at normal temperature, no extra curing cost is generated, no toxic gas is generated, the film is healthy and environment-friendly, the formed film has high transmittance, excellent weather resistance, super-clear water self-cleaning property and antifogging property, and the film has high adhesive force on a glass substrate and strong stability after being cured.

2. The invention can select different coating modes and is convenient to use under different conditions.

3. The coating liquid is an aqueous system, and is environment-friendly and pollution-free.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required to be used in the description of the embodiments are briefly introduced below, and it is obvious that the drawings in the description below are only some embodiments of the present invention, and it is obvious for those skilled in the art that other drawings can be obtained according to the drawings without creative efforts.

FIG. 1: transmittance of the photovoltaic substrates of examples 1-6 before and after coating was compared;

FIG. 2 is a schematic diagram: transmittance of the photovoltaic glass of comparative examples 1-2 was compared before and after coating;

FIG. 3: the transmittance of the photovoltaic substrates of examples 1-6 was compared after the coated photovoltaic substrates were subjected to the double 85 test;

FIG. 4: the transmittance of the photovoltaic glass in comparative examples 1-2 was compared after the coated photovoltaic glass was subjected to a double 85 test;

FIG. 5: the transmittance of the photovoltaic substrates in examples 1-6 was compared after the coated photovoltaic substrates were subjected to salt spray testing;

FIG. 6: after the coated photovoltaic glass is subjected to a salt spray test, the transmittance of the photovoltaic glass in comparative examples 1-2 is compared;

FIG. 7: the transmittance of the photovoltaic substrates in examples 1-6 was compared after the coated photovoltaic substrates were subjected to high and low temperature tests;

FIG. 8: after the coated photovoltaic glass is subjected to high and low temperature tests, the transmissivity of the photovoltaic glass in the comparative examples 1-2 is compared;

FIG. 9: hydrophilicity plots of the photovoltaic glass coatings of examples 1-4;

FIG. 10: comparative examples 1-2 are graphs showing hydrophilicity of photovoltaic glass coatings;

Detailed Description

The invention is further described with reference to the following figures and specific examples.

Example 1

The materials are added according to the proportion in the table 1, and the specific method is as follows:

1. preparation of coating solution

Preparing a solvent in the step (1), uniformly mixing deionized water and a small amount of alcohol, and stirring at room temperature for 30min;

step (2) preparation of solution a: mixing silicate and hollow silica nano-spheres in a 4/5 total solvent in the step (1) according to the mass ratio of 1;

step (3) preparation of solution B: dissolving the film forming assistant and the filler in the rest solvent, and stirring for 3 hours at 45 ℃ to obtain a solution B;

and (4) mixing the solution A obtained in the step (2) with the solution B obtained in the step (3), stirring for 24 hours at room temperature, and aging for 3 days at room temperature to obtain the final coating liquid capable of being directly coated.

2. Glass plate coating film layer

Pretreating a photovoltaic glass substrate on a solar cell by using glass cleaning liquid, cleaning by using clear water after pretreatment, and naturally drying after cleaning;

filling the prepared antireflection coating liquid into coating equipment; and (3) placing the device on a treated photovoltaic glass substrate, coating at a coating speed of 150mm/min, and naturally drying the coated film, wherein the thickness of the film layer is 105nm.

Example 2

The materials are added according to the material proportion in the table 1, the specific steps are carried out according to the example 1, and the parameters in each step are shown in the table 2.

Example 3

Example 4

1. The preparation of the coating liquid is carried out,

step (1) preparing a solvent, namely uniformly mixing deionized water and a small amount of alcohol, and stirring at room temperature for 30min;

step (2) preparation of solution a: mixing silicate and hollow silica nanospheres in the solvent in the step (1) according to the mass ratio of 1;

dissolving the film-forming additive in the solution A, stirring for 1 hour at 45 ℃,

and (4) dissolving a filling agent into the solution obtained in the step (3), stirring for 24 hours at room temperature, and then aging for 5 days at room temperature to obtain the final coating liquid capable of being directly coated.

2. Glass plate coating film layer

filling the prepared antireflection coating liquid into coating equipment; and (3) placing the device on a treated photovoltaic glass substrate, coating at a coating speed of 150mm/min, and naturally drying the coated film, wherein the thickness of the film layer is 116nm.

Example 5

The materials are added according to the material proportion in the table 1, the specific steps are carried out according to the example 1, and the parameters in each step are referred to the table 2.

Example 6

TABLE 1 proportion of materials added

Wherein: parts by weight: according to the mass;

lithium potassium silicate: the proportion of lithium and potassium is 9-10, the modulus is 3, and the content is 35%;

film-forming assistant 1: dipropylene glycol tert-butyl ether, content 90%;

film-forming assistant 2: dipropylene glycol monobutyl ether, content 90%;

ethanol: the content is 99 percent;

isopropyl alcohol: the content is 99 percent;

deionized water: resistivity of 18.25M Ω. Cm;

filling agent: solid silica spheres with a particle size of 10nm and a content of 20 percent;

nanosphere: hollow silicon dioxide nanospheres with the particle size of 70nm and the wall thickness of 10nm;

substrate 1: photovoltaic glass;

substrate 2: a light weight flexible photovoltaic substrate.

TABLE 2 parameter setting in the procedure

Comparative example 1

The difference compared to example 1 is that no film-forming aid was added to the batch.

Comparative example 2

The difference compared to example 1 is that no filler was added to the batch.

The glass sheets prepared in the examples and comparative examples were tested for their properties.

Test example 1 measurement of transmittance

A detection instrument: an ultraviolet-visible spectrophotometer model Hitachi-U4100;

the detection method comprises the following steps: putting the photovoltaic glass coated with the photovoltaic antireflection coating into a spectrophotometer;

the photovoltaic glass was tested for transmittance before and after coating, as shown in fig. 1-2.

Test example 2-double 85 test

A detection instrument: a high-low temperature damp-heat test chamber with the model GDS-100L;

the detection method comprises the following steps: and putting the photovoltaic glass coated with the photovoltaic antireflection complementary coating into a high-low temperature damp-heat test box. Wherein the program set constant temperature 85 deg.C, constant humidity 85%, run for 120h, test transmittance as shown in figures 3-4.

Test example 3 salt spray test

And (3) detecting an instrument: a salt spray corrosion test chamber with the model of YWX/Q-250L;

the detection method comprises the following steps: and putting the photovoltaic glass coated with the photovoltaic antireflection complementary coating into a salt spray corrosion test box. The salt spray test was carried out for 36h at a salt spray concentration of 5% and a temperature of 35 c, and the transmission of the test was as shown in fig. 5-6.

Test example 4 high and Low temperature cycling test

the detection method comprises the following steps: and (3) placing the photovoltaic glass coated with the photovoltaic antireflection complementary coating into a high-low temperature damp-heat test box. Wherein the program is set to high temperature of 85 ℃ and kept for 3h; keeping the temperature at-40 ℃ for 3h; cycling 20 times, the test transmission is shown in fig. 7-8.

Test example 5 hydrophobic detection

A detection instrument: contact angle measuring instrument, model: SDC-200S

The detection method comprises the following steps: the water drop angle tester is started, the computer connected with the water drop angle tester is used for placing the photovoltaic glass coated with the photovoltaic antireflection coating on the sample table, then manual dropping liquid (automatic dropping liquid) dropping liquid standard is 1-2 microliters, and then the sample table is lifted to enable the photovoltaic glass to receive the water drops. And finally clicking the frozen measuring scale to move the displayed measuring scale to the left or right or up or down by clicking a shortcut button, wherein the measuring scale is tangent to the edge of the liquid drop. Then clicking the downward moving measuring scale to coincide the intersection point with the edge of the liquid drop, clicking the left-handed button to intersect the measuring scale with one side of the liquid drop, and clicking to calculate the contact angle, as shown in fig. 9-10.

Test example 6 hardness test

A detection instrument: portable pencil mar experiment appearance, the model: model QHQ-A.

The detection method comprises the following steps: the photovoltaic glass coated with the photovoltaic antireflection coating is placed on a desktop, a pencil and a measured coating are always kept to form a 45-degree included angle by three points of contact with the measured surface (two points are two wheels, and one point is a pencil lead), and the pencil hardness meter is pushed to move horizontally by force, so that the test process can be completed, and the deformation resistance of the coating is measured. Identified by the pencil designation, the test results are shown in table 3.

Table 3: coating hardness test results

As can be seen from the detection results of figures 1-10 and table 3, the film prepared by the scheme has excellent performances in the aspects of transmissivity, hardness, high and low temperature resistance, salt spray resistance, hydrophilicity and the like compared with the comparative example, and the increase range is more unexpected.

The above is only a preferred embodiment of the present invention, and the protection scope of the present invention is not limited to the above-mentioned embodiments, and all technical solutions belonging to the idea of the present invention belong to the protection scope of the present invention. It should be noted that modifications and embellishments within the scope of the invention may occur to those skilled in the art without departing from the principle of the invention, and are considered to be within the scope of the invention.

Claims

1. A room-temperature-curable water-based coating composition characterized by comprising:

a hydrolytic condensate of silicate, wherein the silicate comprises one or more of sodium silicate, lithium silicate, potassium silicate and lithium potassium silicate, and the modulus is 2.5-5;

the mass ratio of the silicate to the hollow silica nanospheres is 8;

the mass ratio of the film-forming additive to the silicate is 0.001-0.2;

the mass ratio of the filler to the silicate is 0.5-1.5.

2. The room-temperature-curable aqueous coating composition according to claim 1, wherein: the hollow silicon dioxide nanospheres have the particle size of 10-80nm and the wall thickness of 3-20nm.

3. The room-temperature-curable aqueous coating composition according to claim 1, wherein: the film-forming assistant is alcohol ether, and comprises one or more of propylene glycol methyl ether, propylene glycol ethyl ether, propylene glycol butyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monopropyl ether, dipropylene glycol tert-butyl ether, dipropylene glycol monobutyl ether and tripropylene glycol n-butyl ether propylene glycol phenyl ether.

4. The room-temperature-curable aqueous coating composition according to claim 1, wherein: the filler is solid silicon dioxide pellets or silicon oxide aerogel, and the particle size is 3-15nm.

5. The room-temperature-curable aqueous coating composition according to claim 1, wherein: the hydrolytic condensation product of the silicate is prepared by a sol-gel method.

6. The room-temperature-curable aqueous coating composition according to claim 1, wherein: also comprises a solvent, and the mass ratio of the solvent to the silicate is 30-110.

7. The room-temperature curable aqueous coating composition according to claim 6, wherein: the solvent is a mixture of water and lower alcohol, wherein the water accounts for 75-90% by mass.

8. A method for preparing a normal-temperature curing type aqueous coating solution, which comprises the coating solution of claim 6, and is characterized in that: comprises the following steps

Mixing silicate, partial solvent and hollow silica nanosphere to form a hydrolysis condensate solution A of silicate;

mixing the film-forming assistant, the filler and the residual solvent to form a solution B;

and mixing the solution A and the solution B to form a coating liquid.

9. The method for preparing a normal-temperature curing type aqueous coating solution according to claim 8, wherein the method comprises the following steps: in the step of forming the coating liquid, the mixture is uniformly stirred at the temperature of 30-60 ℃.

10. The method for preparing a normal-temperature curing type aqueous coating solution according to claim 8, wherein the method comprises the following steps: and aging for at least 24 hours after the solution A and the solution B are uniformly mixed.