CN118291025A - Water-based wind power blade finishing paint with excellent alkali resistance and weather resistance and preparation method thereof - Google Patents

Abstract

The invention relates to the technical field of coatings, in particular to an aqueous wind power blade finishing paint with excellent alkali resistance and weather resistance and a preparation method thereof. The coating comprises a component A and a component B, wherein the component A comprises water, a first aqueous hydroxy acrylic emulsion, a film forming auxiliary agent, an abrasion-resistant filler, an aqueous polyurethane dispersion, a hybrid emulsion, a wax emulsion and other auxiliary agents; the component B comprises an aqueous isocyanate curing agent and propylene glycol diacetate. The coating has the characteristics of good flexibility and strength, high wear resistance and quick drying, and meanwhile, has excellent acid and alkali resistance, water resistance, oil resistance and weather resistance, effectively improves the alkali resistance and weather resistance of the water-based wind power blade finishing paint with high content of low hydroxyl polyurethane resin component, and can realize long-term protection of the wind power blade on land or at sea.

Description

Water-based wind power blade finishing paint with excellent alkali resistance and weather resistance and preparation method thereof

Technical Field

The invention relates to the technical field of coatings, in particular to an aqueous wind power blade finishing paint with excellent alkali resistance and weather resistance and a preparation method thereof.

Background

In recent years, the wind energy industry in China develops rapidly, and the worldwide share of wind power production is improved year by year.

The wind power blade coating is used as an important protective material in a wind power industry chain, protects blades from being corroded by ultraviolet light, sand dust, rainwater, icing and other environmental factors, protects the fan from long-term, efficient and safe operation, and has wide market prospect.

With the continuous development of technology, the coating system of the wind power blade gradually adopts an environment-friendly coating system, wherein the wind power blade finishing paint mostly adopts water-based coating, such as related products of Magazine and Jordan in the market. The water-based paint has the advantages of easiness in construction, safety, environmental friendliness and the like, and is favored by wind power blade manufacturers.

At present, the low-hydroxyl polyurethane has the characteristics of quick drying and high flexibility, so that the coating efficiency of the finish paint, the key performances of wind sand resistance, rain erosion resistance and the like are improved; therefore, the resin is introduced into the water-based finishing paint of the wind power blade as a film forming material. However, the aqueous polyurethane coating can be subjected to hydrolysis reaction essentially under alkaline conditions, the alkali resistance is general, the low hydroxyl content of the low hydroxyl polyurethane leads to lower crosslinking density of the coating, the alkali resistance of the coating is further reduced, and the ultraviolet ageing performance of the finish paint is also reduced due to lower crosslinking density. In the prior literature and related researches, there are few reports on how to enhance the alkali resistance and weather resistance of low-hydroxyl polyurethane coatings. Therefore, how to develop a wind power blade water-based finishing paint with excellent alkali resistance and weather resistance, high drying rate and high flexibility and the like is a problem which needs to be solved urgently in the field.

Disclosure of Invention

In order to solve the problems of the prior art mentioned in the background art, the invention provides an aqueous wind-power blade finishing paint with excellent alkali resistance and weather resistance, and aims to improve the alkali resistance and weather resistance of the aqueous wind-power blade finishing paint with high content of low hydroxyl polyurethane resin component.

The aqueous wind power blade finishing paint with excellent alkali resistance and weather resistance comprises a first component and a second component, wherein the first component comprises water, a first aqueous hydroxyl acrylic emulsion, a film forming auxiliary agent, an abrasion-resistant filler, an aqueous polyurethane dispersion, a hybrid emulsion, a wax emulsion and other auxiliary agents; the component B comprises a water-based isocyanate curing agent and propylene glycol diacetate; the preparation process of the hybrid emulsion comprises the following steps: mixing and heating a second aqueous hydroxy acrylic emulsion, an amphiphilic silane coupling agent and L-lysine for reaction to obtain a mixture M; and then adding tetraethoxysilane into the mixture M and heating for reaction to obtain the hybrid emulsion.

In some embodiments, the other auxiliary agents include aqueous dispersants, aqueous defoamers, aqueous thickeners, titanium dioxide, matting powders, aqueous color paste; the A component comprises, by weight, 6-10 parts of water, 9.6-14.4 parts of a first aqueous hydroxy acrylic emulsion, 2-6 parts of a film forming additive, 0.4-0.6 part of an aqueous dispersing agent, 0.2-0.3 part of an aqueous defoaming agent, 0.2-0.4 part of an aqueous thickening agent, 17-25 parts of titanium dioxide, 5-10 parts of an abrasion-resistant filler, 1.5-2.5 parts of matting powder, 9.6-14.4 parts of a hybrid emulsion, 20-28 parts of an aqueous polyurethane dispersion, 3-5 parts of a wax emulsion and 0-0.730 part of aqueous color paste; the component B comprises 50-75 parts of aqueous isocyanate curing agent and 25-50 parts of propylene glycol diacetate.

In some embodiments, the hybrid emulsion is prepared by:

mixing a second aqueous hydroxy acrylic emulsion, an amphiphilic silane coupling agent and L-lysine, and performing a first-stage heating reaction to obtain a mixture M;

Dropwise adding tetraethoxysilane into the mixture M, performing a second-stage heating reaction, and cooling to room temperature after the reaction is finished to obtain a hybrid emulsion;

Wherein the mass ratio of the second aqueous hydroxyl acrylic emulsion to the amphiphilic silane coupling agent to the ethyl orthosilicate to the L-lysine is (80-90): (2-5): (8-16): (0.03-0.06).

In some embodiments, the first stage heating reaction temperature is (45-60) deg.c and the reaction time is (0.5-1.5) h; the dripping speed of the tetraethoxysilane is (0.5-1) drops/second; the second stage heating reaction temperature is (45-60) DEG C, and the reaction time is (4-6) h.

In some embodiments, the mass ratio of the component a to the component b is (5-10): 1.

In some embodiments, the first aqueous hydroxyacrylic acid emulsion and the second aqueous hydroxyacrylic acid emulsion have a solids content of (40-55)%, wherein the hydroxyl content is (2-4.2)% of the total mass of the hydroxyacrylic resin; the film forming additive is one or two of dipropylene glycol butyl ether and diethylene glycol monobutyl ether; the wear-resistant filler comprises one or a combination of more of feldspar powder, fine powder, wollastonite powder, quartz powder and quartz sand; the aqueous polyurethane dispersion is a low-hydroxyl aqueous polyurethane dispersion, wherein the hydroxyl content is (0-2)% of the total mass of the aqueous polyurethane resin, the solid content is (35-55)%, the surface drying time is less than 20min at room temperature, and the real drying time is less than 1h; the wax emulsion is one or a combination of more than one of aqueous polytetrafluoroethylene dispersion PTFE-1004A, PTFE-1008, and the solid content of the wax emulsion is 50-55wt%.

In some embodiments, the aqueous isocyanate curing agent is a polyether modified HD I trimer oligomer having a high NCO-group content, wherein the NCO-content is 18 to 22% of the total mass of the molecule, and has the structural formula:

Wherein, the structure of R is:

wherein n=10 to 100.

In some embodiments, the aqueous dispersant is one or more combinations of BYK-180, BYK-190, UKa 690w, SN5040, X-405; the water-based defoamer is one or a combination of more of BYK-024, tego810, tego901w, tego902w, UKa 290w and UKa 295 w; the aqueous thickener is one or more of WT-105A, U805, 812W, COATEX XS71, RM2020, BR 125P; the titanium dioxide is rutile titanium dioxide and comprises one or more of R706, R996 and R5566; the extinction powder is modified silicon dioxide extinction powder with the surface treated by wax, the porosity is 1.8mL/g, the oil absorption value is 260-300 g, the particle size is 4.5-5.5 mu m, and the pH is 6.0-7.0.

In some embodiments, the color paste comprises one or more of an aqueous iron yellow paste, an aqueous iron black paste, an aqueous blue paste.

The invention also provides a preparation method of the aqueous wind power blade finishing paint with excellent alkali resistance and weather resistance, wherein:

The preparation of the component A comprises the following steps:

adding water, a first aqueous hydroxy acrylic emulsion, a film forming additive, an aqueous dispersing agent, an aqueous defoaming agent and an aqueous thickening agent into a stainless steel tank filled with condensed water according to the formula proportion, and dispersing to obtain a mixture N;

Adding titanium pigment, wear-resistant filler and extinction powder into the mixture N according to the formula proportion, performing sanding treatment until the fineness is less than 30 microns, and then adopting filtering treatment to obtain paint;

weighing the paint, and adding wax emulsion, aqueous polyurethane dispersion, hybrid emulsion and aqueous color paste into the paint according to the formula proportion, and dispersing at high speed to obtain a component A;

The preparation of the component B comprises the following steps:

and uniformly dispersing the water-based isocyanate curing agent and propylene glycol diacetate according to the formula proportion to obtain the component B.

Based on the above, compared with the prior art, the aqueous wind power blade finishing paint with excellent alkali resistance and weather resistance provided by the invention has the following technical effects:

The invention provides a water-based wind power blade finishing paint which has the characteristics of good flexibility and strength, high wear resistance and quick drying, and is excellent in acid and alkali resistance, water resistance, oil resistance and weather resistance, and the alkali resistance and weather resistance of the water-based wind power blade finishing paint with high content of low-hydroxyl polyurethane resin component are effectively improved; the drying rate is high, the coating interval between two topcoats is short, the improvement of the coating efficiency of wind power blade manufacturers is facilitated, and the cost is reduced; meanwhile, the coating is excellent in wear resistance, alkali resistance and weather resistance, and can realize long-term protection of the onshore or offshore wind power blade.

Additional features and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objectives and other advantages of the invention may be realized and attained by the structure and/or components pointed out in the written description and claims.

Drawings

FIG. 1 is a sample graph of the alkali resistance test of the examples and comparative examples provided by the present invention.

Detailed Description

For the purpose of making the objects, technical solutions and advantages of the embodiments of the present invention more apparent, the following description will be made in conjunction with the technical solutions in the embodiments of the present invention, and it is apparent that the described embodiments are some, but not all, embodiments of the present invention; the technical features designed in the different embodiments of the invention described below can be combined with each other as long as they do not conflict with each other; all other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.

In the description of the present invention, it should be noted that all terms used in the present invention (including technical terms and scientific terms) have the same meaning as commonly understood by one of ordinary skill in the art to which the present invention belongs and are not to be construed as limiting the present invention; it will be further understood that terms used herein should be interpreted as having a meaning that is consistent with their meaning in the context of this specification and the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

The invention provides a preparation method of an aqueous wind power blade finishing paint with excellent alkali resistance and weather resistance, which comprises the following steps:

1. the preparation of the component A comprises the following steps:

adding water, a first aqueous hydroxy acrylic emulsion, a film forming additive, an aqueous dispersing agent, an aqueous defoaming agent and an aqueous thickening agent into a stainless steel tank filled with condensed water according to the formula proportion, and dispersing to obtain a mixture N;

Adding titanium pigment, wear-resistant filler and extinction powder into the mixture N according to the formula proportion, performing sanding treatment until the fineness is less than 30 microns, and then adopting filtering treatment to obtain paint;

And (3) weighing the paint, and adding wax emulsion, aqueous polyurethane dispersion, hybrid emulsion and aqueous color paste into the paint according to the formula proportion, and dispersing at high speed to obtain the component A.

2. The preparation of the component B comprises the following steps:

and uniformly dispersing the water-based isocyanate curing agent and propylene glycol diacetate according to the formula proportion to obtain the component B.

Wherein the formula of the component A and the component B is as follows:

The A component comprises, by weight, 6-10 parts of water, 9.6-14.4 parts of a first aqueous hydroxy acrylic emulsion, 2-6 parts of a film forming additive, 0.4-0.6 part of an aqueous dispersing agent, 0.2-0.3 part of an aqueous defoaming agent, 0.2-0.4 part of an aqueous thickening agent, 17-25 parts of titanium dioxide, 5-10 parts of an abrasion-resistant filler, 1.5-2.5 parts of matting powder, 9.6-14.4 parts of a hybrid emulsion, 20-28 parts of an aqueous polyurethane dispersion, 3-5 parts of a wax emulsion and 0-0.730 part of aqueous color paste;

the component B comprises 50-75 parts of aqueous isocyanate curing agent and 25-50 parts of propylene glycol diacetate; wherein the mass ratio of the component A to the component B is (5-10): 1.

Wherein, the hybrid emulsion is self-made, and the preparation process is as follows:

mixing a second aqueous hydroxy acrylic emulsion, an amphiphilic silane coupling agent and L-lysine, and performing a first-stage heating reaction to obtain a mixture M;

Dropwise adding tetraethoxysilane into the mixture M, performing a second-stage heating reaction, and cooling to room temperature after the reaction is finished to obtain a hybrid emulsion; the heating reaction temperature in the first stage is (45-60) DEG C, and the reaction time is (0.5-1.5) h; the dripping speed of the tetraethoxysilane is (0.5-1) drops/second; the second stage heating reaction temperature is (45-60) DEG C, and the reaction time is (4-6) h.

Wherein the mass ratio of the second aqueous hydroxyl acrylic emulsion to the amphiphilic silane coupling agent to the ethyl orthosilicate to the L-lysine is (80-90): (2-5): (8-16): (0.03-0.06).

The invention also provides the following examples and comparative formulations (unit: parts by weight) as shown in Table 1 below:

TABLE 1

Specifically, the raw materials used in the examples and comparative examples in table 1 were:

(1) The water is deionized water;

(2) The solid content of the first aqueous hydroxy acrylic emulsion is 45%, and the hydroxy content is 4.2% of the total mass of the hydroxy acrylic resin;

(3) The film forming auxiliary agent is dipropylene glycol butyl ether;

(4) The aqueous dispersant is BYK-190;

(5) The water-based defoamer is BYK-024;

(6) The aqueous thickener is U805;

(7) The titanium dioxide is rutile titanium dioxide, and specifically is R996;

(8) The wear-resistant filler is feldspar powder;

(9) The extinction powder is modified silicon dioxide extinction powder with the surface treated by wax, the porosity is 1.8mL/g, the oil absorption value is 260g (calculated by 100g sample), the particle size is 5.0 mu m, and the pH is 7.0;

(10) The aqueous polyurethane dispersion is a low-hydroxyl aqueous polyurethane dispersion, the hydroxyl content is 1.5% of the total mass of the aqueous polyurethane resin, the solid content is 35%, the surface drying time is less than 20min at room temperature, and the real drying time is less than 1h;

(11) The hybrid emulsion is self-made in a laboratory

In examples 1,2 and comparative examples 1,2,3, the preparation method of the hybrid emulsion includes the steps of:

s1: mixing the second aqueous hydroxy acrylic emulsion, KH-570 and L-lysine, and performing a first stage heating reaction;

S2: and (3) dropwise adding tetraethoxysilane into the mixture, performing a second-stage heating reaction, and cooling to room temperature after the reaction is finished to obtain the hybrid emulsion. The heating reaction temperature in the first stage is 45 ℃, and the reaction time is 1.5h; the addition rate of the 'dropwise addition' is 1 drop/second; the heating reaction temperature in the second stage is 45 ℃, and the reaction time is 6 hours.

Wherein the solid content of the first aqueous hydroxy acrylic emulsion is 45%, and the hydroxy content is 4.2% of the total mass of the resin; the addition amount of the aqueous hydroxyl acrylic emulsion is 90 parts by weight; KH-570 is an amphiphilic silane coupling agent, and the addition amount is 2 parts; the ethyl orthosilicate is a commercially available analytically pure product, and the addition amount is 8 parts; l-lysine was a commercially available analytically pure product with an addition of 0.05 parts.

In comparative example 4, the preparation method of the hybrid emulsion includes the steps of:

S1: mixing the second aqueous hydroxy acrylic emulsion, KH-560 and L-lysine, and performing a first stage heating reaction;

S2: and (3) dropwise adding tetraethoxysilane into the mixture, performing a second-stage heating reaction, and cooling to room temperature after the reaction is finished to obtain the hybrid emulsion. The heating reaction temperature in the first stage is 45 ℃, and the reaction time is 1.5h; the addition rate of the 'dropwise addition' is 1 drop/second; the heating reaction temperature in the second stage is 45 ℃, and the reaction time is 6 hours.

Wherein the solid content of the first aqueous hydroxy acrylic emulsion is 45%, and the hydroxy content is 4.2% of the total mass of the resin; the addition amount of the aqueous hydroxyl acrylic emulsion is 90 parts by weight; KH-560 is a hydrophilic silane coupling agent, and the addition amount is 2 parts; the ethyl orthosilicate is a commercially available analytically pure product, and the addition amount is 8 parts; l-lysine was a commercially available analytically pure product with an addition of 0.05 parts.

In comparative example 5, the preparation method of the hybrid emulsion includes the steps of:

S1: mixing the second aqueous hydroxyl acrylic emulsion with L-lysine, dropwise adding tetraethoxysilane into the mixture, heating for reaction, and cooling to room temperature after the reaction is finished to obtain the hybrid emulsion. The addition rate of the 'dropwise addition' is 1 drop/second; the heating reaction temperature is 45 ℃, and the reaction time is 6 hours. Wherein the solid content of the first aqueous hydroxy acrylic emulsion is 45%, and the hydroxy content is 4.2% of the total mass of the resin; the addition amount of the aqueous hydroxyl acrylic emulsion is 90 parts by weight; the ethyl orthosilicate is a commercially available analytically pure product, and the addition amount is 8 parts; l-lysine was a commercially available analytically pure product with an addition of 0.05 parts.

(12) The wax emulsion was PTFE-1004A, with a solids content of 50% by weight.

(13) The aqueous isocyanate curing agent is a polyether modified HD I trimer oligomer with high NCO-content, the NCO-content is 20% of the total molecular mass, and the structural formula is as follows:

Wherein, the structural formula of R is:

wherein n=10 to 100.

The preparation process of the coatings of the examples and comparative examples is:

Adding deionized water, diethylene glycol butyl ether, a first aqueous hydroxy acrylic emulsion, an aqueous dispersing agent, an aqueous defoaming agent and an aqueous thickening agent according to the formula amount into a stainless steel tank filled with condensed water, and dispersing for 5min at 500 r/min;

Adding titanium dioxide, feldspar powder and extinction powder according to the formula amount, adding 1000g of zirconium beads, and sanding for 90min at 1600r/min until the fineness is less than 30 microns;

Then, filtering the paint by adopting a 100-mesh filter screen, weighing the paint, placing the paint in an iron tank, adding the wax emulsion, the aqueous polyurethane dispersion, the hybrid emulsion and the aqueous color paste according to the formula amount, and dispersing at a high speed for 10min at 1000r/min to obtain a component A;

Adding the water-based isocyanate curing agent and propylene glycol diacetate with the formula amount into an iron tank, and dispersing for 4min at 400r/min to obtain the component B.

After the products prepared in the above examples and the products prepared in the comparative examples were mixed and used according to the proportions of the component A and the component B in Table 1, the following performance tests were conducted and the test results were obtained:

(1) The components A and B of the comparative example and the example are mixed according to the formula, stirred uniformly, and subjected to mechanical and wear resistance test, and the test results are shown in Table 2:

TABLE 2 mechanical and wear resistance test results

(2) The components A and B of the comparative example and the example are mixed according to the formula, uniformly stirred and subjected to medium resistance, the test results are shown in table 3, and the photos of each group of templates after alkali resistance are shown in fig. 1:

TABLE 3 Medium resistance

Among them, as shown in fig. 1, comparative example 1 showed a lot of foaming on the rear surface of alkali resistance 240h, and comparative example 2, example 1, example 2 and comparative example 3 were all good on the rear surface of alkali resistance 240 h.

(3) The components A and B of the comparative example and the example are mixed according to the formula, uniformly stirred, and subjected to a manual accelerated aging resistance test, and the test results are shown in Table 4:

TABLE 4 weather resistance

(4) The components A and B of the comparative example and the example are mixed according to the formula, uniformly stirred, subjected to a roller coating construction process test, tested for wet film thickness and drying time, and observed for the surface state of a paint film, and the results are shown in Table 5:

Table 5 test results of roll coating process

Wherein the diluent is deionized water.

(5) Analysis of the above test data shows that:

1) As can be seen from table 2:

In examples 1-2 and comparative examples 1-3, when the coupling agent in the hybrid emulsion is KH 570, and the addition amount of the hybrid emulsion is increased from 0wt% to 40wt%, the tensile strength of a paint film is gradually increased from 10.65 to 14.21MPa, the elongation at break is reduced from 163.8% to 61.97%, and the wear resistance is increased from 65 to 37.8mg;

in comparative example 4, when the coupling agent in the hybrid emulsion was KH560, precipitation occurred in the hybrid emulsion;

in comparative example 5, the tensile strength of the paint film was 8.4MPa, the elongation at break was 71.03% and the abrasion resistance was 81.7mg in the absence of the coupling agent in the hybrid emulsion.

From this, it can be seen that: when the coupling agent in the hybrid emulsion is KH 570, the hybrid emulsion improves the strength and wear resistance of the paint film, but reduces the flexibility to a certain extent. The silica inorganic network structure is formed by dehydrating and crosslinking silicon hydroxyl groups on the surface of a silica shell layer in the hybrid emulsion, and the hardness and crosslinking density of a paint film are improved, so that the strength and wear resistance of the paint film are improved, but the segment in the inorganic silica network structure is short, the toughness is poor, and the flexibility of the paint film is reduced to some extent. Overall, the formulations of examples 1-2 and comparative examples 1-2 were excellent in combination with respect to tensile strength, elongation at break and abrasion resistance, except that the flexibility of comparative example 3 was less than 70%.

In addition, in comparative example 4, the hybrid emulsion prepared using the KH 560 hydrophilic coupling agent flocculated, which may be that KH 560 could not be uniformly spread on the surface of latex particles, resulting in uneven polymerization growth of silica, and thus flocculation and precipitation of the hybrid emulsion.

In contrast, in comparative example 5, the paint film strength, flexibility and abrasion resistance were all reduced in comparative example 1-2 without the coupling agent KH570 in the hybrid emulsion, which is mainly due to the low degree of polymerization of silica and poor compatibility with organic resins.

2) As can be seen from table 3:

The comparative example 1 has no hybrid emulsion added, and meets the requirements of water resistance, acid resistance and oil resistance, but a large amount of foaming occurs after alkali resistance, mainly because the low-hydroxyl polyurethane in the formula has higher content and low crosslinking density, and simultaneously, the urethane groups in the polyurethane molecular structure are partially hydrolyzed under the long-term corrosion of alkaline environment, so that the crosslinking density of a paint film is further reduced, and the foaming phenomenon occurs.

In addition, the comparative examples 2, 1,2 and 3 all had no foaming after 240h alkali resistance, which indicates that the introduction of the hybrid emulsion prepared according to the application improved the alkali resistance of the paint film. The reasons for improving the alkali resistance of paint films by the hybrid emulsion mainly comprise two aspects. On one hand, the hybrid emulsion is introduced to form an organic-inorganic covalent bonding network structure, the inorganic silicon dioxide network structure is stable, and a support is formed for the hydrolyzable organic network structure, so that the alkali resistance is improved; on the other hand, the silicon dioxide shell structure plays a role in wrapping and protecting the polyurethane molecules embedded in the interior, delays the corrosion of the medium in the external environment on the polyurethane molecules in the interior, and further slows down the hydrolysis, thereby improving the alkali resistance.

In comparative example 5, the hybrid emulsion is free of coupling agent, and a large amount of foaming occurs after alkali resistance, which is mainly that the silicon dioxide formed in the hybrid emulsion has low polymerization degree and free distribution, the inorganic silicon dioxide network is seriously separated from the polyurethane structure, and the protection effect on the polyurethane network structure is poor.

3) As can be seen from table 4:

In examples 1-2 and comparative examples 1-3, when the coupling agent in the hybrid emulsion is KH570, and the addition amount of the hybrid emulsion is increased to 40%, the pulverization grade of a paint film after ultraviolet aging for 1500 hours is reduced from 2 grade to 0 grade, no cracking and discoloration occur, the adhesive force after aging is between 13.7 and 16.4MPa, and the elongation at break after aging is reduced from 23.7% to 13.3%.

In comparative example 5, when KH 570 coupling agent was not added to the hybrid emulsion, the paint film was pulverized 2-stage after ultraviolet aging for 1500 hours, free from cracking and discoloration, 9.2MPa in adhesion after aging, and 8.3% in elongation at break after aging

From this, it can be seen that: the introduction of the hybrid emulsion added with the KH 570 coupling agent improves the weather resistance of a paint film, and when the addition amount of the hybrid emulsion reaches 20wt%, the paint film is free from pulverization after aging; the inorganic silicon dioxide network structure formed by the hybrid emulsion has higher proportion, the silicon-oxygen-silicon bond energy in the inorganic network structure is high, the stability is good, and a certain supporting effect is achieved on the film forming material structure, so that the weather resistance of a paint film is improved. However, in comparative example 5, when KH 570 coupling agent was not added to the hybrid emulsion, powdering after paint film aging was not improved as compared with comparative example 1, and both adhesion and fracture productivity were lowered after aging, which further suggests that KH 570 coupling agent in the hybrid emulsion has a key effect on the formation of a unique organic-inorganic shell-core structure.

4) As can be seen from table 5:

In examples 1-2 and comparative examples 1-3, the coupling agent in the hybrid emulsion is KH570, when the adding amount of the hybrid emulsion is increased from 0 to 40wt%, the surface drying time of the paint is reduced from 22 to 17min, the real drying time is reduced from 40 to 30min, and the paint film roller coating surface state is even, and the defects of foaming, eye opening and the like are avoided. It follows that the introduction of the hybrid emulsion does not adversely affect the drying rate of the paint film and the state of the roll-coated surface. In comparative example 5, the coating was dried for 20min and dried for 40min without KH570 in the hybrid emulsion, slightly lower than in example 1.

From the above, it can be seen that:

In the whole, the embodiment 1 and the embodiment 2 have excellent comprehensive performance, compared with the scheme without adding the hybrid emulsion, the wear resistance, the alkali resistance, the ageing resistance and the drying speed are obviously improved, the flexibility and the strength are still kept at good level, and the application requirements can be met; the method is suitable for roller coating construction, and has surface drying time of 17min and real drying time of 35min at room temperature; the tensile strength is 12.74-13.47 MPa, the elongation at break is 9641-111.28%, and the wear resistance is 40-41.8 mg; acid-proof 240h, water-proof 240h, oil-proof 96h, alkali-proof 240h, and the like; the UVA-313 has no cracking, pulverization level 0, color change level 0, adhesive force after aging of 13.7-14.2 MPa and elongation at break after aging of 18.5-21.4%.

In summary, the technical scheme of the aqueous wind power blade finishing paint with excellent alkali resistance and weather resistance provided by the invention comprises at least the following design conception, action mechanism and beneficial effects:

In the invention, a self-assembly technology is adopted to construct a silicon dioxide shell layer on the surface of the hydroxyl acrylic emulsion particles to form the hybrid emulsion. The hybrid emulsion and the low-hydroxyl polyurethane dispersion are used as film forming matters, and the aqueous polyisocyanate oligomer is used as a curing agent, so that the bi-component aqueous polyurethane coating is prepared. In this system, the silica shell structure surface contains a large number of silicon hydroxyl groups which can be self-crosslinked and can also undergo crosslinking reaction with residual isocyanate groups. The introduction of the silica shell layer enhances the crosslinking density of the coating, improves the bond energy of a film forming material, plays a certain role in protecting a polyurethane structure, and improves the alkali resistance and weather resistance of the water-based wind power blade finishing paint with high-content low-hydroxyl polyurethane resin component; the hybrid emulsion specifically adopts a specific design:

The hybrid emulsion is prepared by a self-assembly technology, wherein a specific amphiphilic silane coupling agent is selected as a raw material, and can be spread on the surface of latex particles in a mode that a hydrophobic end extends to the inside of the latex particles and a hydrophilic end faces towards a water phase, so that the surface of the latex particles has a large number of silicon hydroxyl sites, silica nano particles are further generated in situ, and a silica shell is formed on the surface of the hydroxyl acrylic latex particles, thereby improving the alkali resistance and weather resistance of the coating. If the amphiphilic silane coupling agent is not selected, when the non-amphiphilic coupling agent KH-560 is selected, a silicon dioxide shell cannot be formed on the surface of the latex particles, flocculation and precipitation of the hybrid emulsion occur, and uneven interaction between coupling agent groups in the formed silicon dioxide and the emulsion possibly occurs; when the coupling agent is not added, although flocculation and precipitation of the hybrid emulsion cannot occur, the silicon dioxide is free in the hybrid emulsion, seeds are difficult to form and grow, the formed silicon dioxide has low crosslinking degree, poor compatibility with resin, serious phase separation and no obvious improvement of alkali resistance and weather resistance of the coating. Meanwhile, the temperature of the first-stage heating reaction and the second-stage heating reaction is controlled within a limited range, so that the formation of a silicon dioxide shell is facilitated, and if the temperature exceeds the limited range, hybrid emulsion colloidal particles can be agglomerated, and the storage stability of the coating is reduced.

The paint provided by the invention has the following effects:

(1) Excellent alkali resistance and weather resistance:

In the invention, hybrid emulsion, low-hydroxyl polyurethane and isocyanate trimer are taken as film forming materials. The hybrid emulsion is prepared by a method for constructing a silicon dioxide shell layer on the surface of the hydroxyl acrylic emulsion colloidal particles by adopting a self-assembly technology, and a large number of silicon hydroxyl groups are distributed on the surface of the silicon dioxide shell layer of the hybrid emulsion. On the one hand, the silicon hydroxyl groups can be self-crosslinked at room temperature in the drying process of the paint film, so that covalent bonding is formed between colloidal particles; on the other hand, a small amount of silicon hydroxyl groups react with isocyanate groups in the curing reaction process, so that the inorganic silicon dioxide network structure and the organic polyurethane network structure form chemical crosslinking. Therefore, the introduction of the silicon dioxide shell layer in the hybrid emulsion greatly improves the crosslinking density of the film forming material, improves the alkali resistance of the coating, and simultaneously, the introduction of the silicon dioxide shell layer also improves the weather resistance of the coating due to the stable chemical property of the formed silicon-oxygen-silicon bond.

(2) High wear resistance:

in general, the wear resistance of a material is related to the hardness, toughness, and surface coefficient of friction of the material. In the invention, the coating has high toughness due to the existence of the low-hydroxyl polyurethane component, and has higher hardness due to the existence of the inorganic network structure; the introduction of the wax emulsion enables the surface of the coating to have a lower friction coefficient; thus, under the synergistic effect of the low hydroxyl polyurethane, the inorganic network structure and the wax emulsion, the paint film has high wear resistance.

(3) The drying rate is fast:

The two-component aqueous coating drying process generally comprises two steps: moisture evaporation and chemical crosslinking. The low-hydroxyl polyurethane resin can be used as a single-component film forming matter, and can be naturally dried to form a film without chemical reaction, and the chemical crosslinking drying process is not required. In the invention, the low-hydroxyl polyurethane resin has higher content in the composition of the film forming material, so that the film forming material also has the characteristic of single-component drying film forming, and after the moisture is volatilized, the surface of a paint film can reach a dry and hands-free state, thereby meeting the drying condition of coating the next finish paint; meanwhile, the silicon hydroxyl on the surface of the silicon dioxide shell can realize room-temperature self-crosslinking curing, and the physical drying rate of the coating is further improved to a certain extent by introducing the silicon dioxide shell.

The test shows that: the obtained coating can be subjected to roller coating construction, and is surface dried for 17min and real dried for 35min at room temperature; the tensile strength is 12.74-13.47 MPa, the elongation at break is 96.41-111.28%, and the wear resistance is 40-41.8 mg; acid-proof 240h, water-proof 240h, oil-proof 96h, alkali-proof 240h, and the like; the UVA-313 has no cracking, pulverization level 0, color change level 0, adhesive force after aging of 13.7-14.2 MPa and elongation at break after aging of 18.5-21.4%; through the technical route, the wind power blade water-based finishing paint developed by the invention has the characteristics of high flexibility, high strength, high wear resistance and quick drying, and meanwhile, the wind power blade water-based finishing paint is excellent in alkali resistance and weather resistance, and the related technical problems are solved.

In summary, the invention provides the water-based wind power blade finishing paint which can be used for roller coating construction, has the characteristics of good flexibility and strength, high wear resistance and quick drying, and is excellent in acid and alkali resistance, water resistance, oil resistance and weather resistance, and the alkali resistance and weather resistance of the water-based wind power blade finishing paint with high content of low-hydroxyl polyurethane resin component are effectively improved; the drying rate is high, the coating interval between two topcoats is short, the improvement of the coating efficiency of wind power blade manufacturers is facilitated, and the cost is reduced; meanwhile, the coating is excellent in wear resistance, alkali resistance and weather resistance, and can realize long-term protection of the onshore or offshore wind power blade.

It should be noted that:

The specific parameters or reagents commonly used in the above embodiments are specific embodiments or preferred embodiments contemplated by the present invention, and are not limiting thereof; and can be adaptively adjusted by those skilled in the art within the concept and the protection scope of the invention.

In addition, unless otherwise specified, the starting materials employed may also be commercially available products conventionally used in the art or may be prepared by methods conventionally used in the art.

In addition, it should be understood by those skilled in the art that although there are many problems in the prior art, each embodiment or technical solution of the present invention may be modified in only one or several respects, without having to solve all technical problems listed in the prior art or the background art at the same time. Those skilled in the art will understand that nothing in one claim should be taken as a limitation on that claim.

Although terms such as aqueous hydroxyacrylic emulsion, film forming aid, abrasion resistant filler, aqueous polyurethane dispersion, hybrid emulsion, wax emulsion, etc. are more used herein, the possibility of using other terms is not precluded. These terms are used merely for convenience in describing and explaining the nature of the invention; they are to be interpreted as any additional limitation that is not inconsistent with the spirit of the present invention.

Finally, it should be noted that: the above embodiments are only for illustrating the technical solution of the present invention, and not for limiting the same; although the invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical scheme described in the foregoing embodiments can be modified or some or all of the technical features thereof can be replaced by equivalents; such modifications and substitutions do not depart from the spirit of the invention.

Claims (10)

1. The aqueous wind power blade finishing paint with excellent alkali resistance and weather resistance comprises a component A and a component B, and is characterized in that: the component A comprises water, a first aqueous hydroxy acrylic emulsion, a film forming auxiliary agent, an abrasion-resistant filler, an aqueous polyurethane dispersion, a hybrid emulsion, a wax emulsion and other auxiliary agents;

the component B comprises a water-based isocyanate curing agent and propylene glycol diacetate;

The preparation process of the hybrid emulsion comprises the following steps: mixing and heating a second aqueous hydroxy acrylic emulsion, an amphiphilic silane coupling agent and L-lysine for reaction to obtain a mixture M; and then adding tetraethoxysilane into the mixture M and heating for reaction to obtain the hybrid emulsion.

2. The aqueous wind-power blade finishing coat excellent in alkali resistance and weather resistance according to claim 1, wherein: the other auxiliary agents comprise a water-based dispersing agent, a water-based defoaming agent, a water-based thickening agent, titanium dioxide, extinction powder and water-based color paste;

The A component comprises, by weight, 6-10 parts of water, 9.6-14.4 parts of a first aqueous hydroxy acrylic emulsion, 2-6 parts of a film forming additive, 0.4-0.6 part of an aqueous dispersing agent, 0.2-0.3 part of an aqueous defoaming agent, 0.2-0.4 part of an aqueous thickening agent, 17-25 parts of titanium dioxide, 5-10 parts of an abrasion-resistant filler, 1.5-2.5 parts of matting powder, 9.6-14.4 parts of a hybrid emulsion, 20-28 parts of an aqueous polyurethane dispersion, 3-5 parts of a wax emulsion and 0-0.730 part of aqueous color paste;

The component B comprises 50-75 parts of aqueous isocyanate curing agent and 25-50 parts of propylene glycol diacetate.

3. The aqueous wind-power blade finishing paint with excellent alkali resistance and weather resistance according to claim 1, wherein the preparation process of the hybridization emulsion is as follows:

mixing a second aqueous hydroxy acrylic emulsion, an amphiphilic silane coupling agent and L-lysine, and performing a first-stage heating reaction to obtain a mixture M;

Dropwise adding tetraethoxysilane into the mixture M, performing a second-stage heating reaction, and cooling to room temperature after the reaction is finished to obtain a hybrid emulsion;

Wherein the mass ratio of the second aqueous hydroxyl acrylic emulsion to the amphiphilic silane coupling agent to the ethyl orthosilicate to the L-lysine is (80-90): (2-5): (8-16): (0.03-0.06).

4. The aqueous wind-power blade finishing coat excellent in alkali resistance and weather resistance according to claim 3, wherein: the heating reaction temperature in the first stage is (45-60) DEG C, and the reaction time is (0.5-1.5) h;

The dripping speed of the tetraethoxysilane is (0.5-1) drops/second; the second stage heating reaction temperature is (45-60) DEG C, and the reaction time is (4-6) h.

5. The aqueous wind-power blade finishing coat excellent in alkali resistance and weather resistance according to claim 1, wherein: the mass ratio of the component A to the component B is (5-10): 1.

6. The aqueous wind-power blade finishing coat excellent in alkali resistance and weather resistance according to claim 1, wherein: the solid content of the first aqueous hydroxyl acrylic emulsion and the second aqueous hydroxyl acrylic emulsion is (40-55)%, wherein the hydroxyl content is (2-4.2)% of the total mass of the hydroxyl acrylic resin;

the film forming additive is one or two of dipropylene glycol butyl ether and diethylene glycol monobutyl ether;

The wear-resistant filler comprises one or a combination of more of feldspar powder, fine powder, wollastonite powder, quartz powder and quartz sand;

The aqueous polyurethane dispersion is a low-hydroxyl aqueous polyurethane dispersion, wherein the hydroxyl content is (0-2)% of the total mass of the aqueous polyurethane resin, the solid content is (35-55)%, the surface drying time is less than 20min at room temperature, and the real drying time is less than 1h;

The wax emulsion is one or a combination of more than one of aqueous polytetrafluoroethylene dispersion PTFE-1004A, PTFE-1008, and the solid content of the wax emulsion is 50-55wt%.

7. The aqueous wind-power blade finishing coat excellent in alkali resistance and weather resistance according to claim 1, wherein: the aqueous isocyanate curing agent is polyether modified HDI trimer oligomer with high NCO-group content, wherein the NCO-content is 18-22% of the total molecular mass, and the structural formula is as follows:

Wherein, the structure of R is:

wherein n=10 to 100.

8. The aqueous wind-power blade finishing coat with excellent alkali resistance and weather resistance as claimed in claim 2, wherein: the water-based dispersing agent is one or a combination of more of BYK-180, BYK-190, UKa 690w, SN5040 and X-405;

The water-based defoamer is one or a combination of more of BYK-024, tego810, tego901w, tego902w, UKa 290w and UKa 295 w;

The aqueous thickener is one or more of WT-105A, U805, 812W, COATEX XS71, RM2020, BR 125P;

the titanium dioxide is rutile titanium dioxide and comprises one or more of R706, R996 and R5566;

The extinction powder is modified silicon dioxide extinction powder with the surface treated by wax, the porosity is 1.8mL/g, the oil absorption value is 260-300 g, the particle size is 4.5-5.5 mu m, and the pH is 6.0-7.0.

9. The aqueous wind-power blade finishing coat with excellent alkali resistance and weather resistance as claimed in claim 2, wherein: the color paste comprises one or a combination of more of water-based iron yellow color paste, water-based iron black color paste and water-based blue color paste.

10. The method for preparing the aqueous wind power blade finishing paint with excellent alkali resistance and weather resistance according to claim 2, which is characterized in that:

The preparation of the component A comprises the following steps:

adding water, a first aqueous hydroxy acrylic emulsion, a film forming additive, an aqueous dispersing agent, an aqueous defoaming agent and an aqueous thickening agent into a stainless steel tank filled with condensed water according to the formula proportion, and dispersing to obtain a mixture N;

Adding titanium pigment, wear-resistant filler and extinction powder into the mixture N according to the formula proportion, performing sanding treatment until the fineness is less than 30 microns, and then adopting filtering treatment to obtain paint;

weighing the paint, and adding wax emulsion, aqueous polyurethane dispersion, hybrid emulsion and aqueous color paste into the paint according to the formula proportion, and dispersing at high speed to obtain a component A;

The preparation of the component B comprises the following steps:

and uniformly dispersing the water-based isocyanate curing agent and propylene glycol diacetate according to the formula proportion to obtain the component B.