CN117887063A

CN117887063A - Polyether aspartate containing aldehyde (ketone) imine and application of polyether aspartate to wind power blade coating

Info

Publication number: CN117887063A
Application number: CN202410026151.8A
Authority: CN
Inventors: 陈俭省; 康少敏; 董艳; 葛达森; 郁维铭
Original assignee: Nanjing Weixin Polymer Technology Co ltd
Current assignee: Nanjing Weixin Polymer Technology Co ltd
Priority date: 2024-01-09
Filing date: 2024-01-09
Publication date: 2024-04-16

Abstract

The invention relates to a coating, in particular to polyether aspartate containing aldehyde (ketone) imine and application thereof in wind power blade coating; the two-component asparagus polyurea coating ensures comprehensive and excellent material performance: as described above, the compound of formula 1, as a macromer having both a soft segment and a ternary crosslinking function, gives the general and excellent material properties that are difficult to obtain for common two-component polyurea coatings, so that the aliphatic asparagust polyurea coating has the performance characteristics of an elastomer in a true sense, and well meets the performance requirements of wind turbine blade coatings including a leading edge protective coating.

Description

Polyether aspartate containing aldehyde (ketone) imine and application of polyether aspartate to wind power blade coating

Technical Field

The invention relates to a coating, in particular to polyether aspartate containing aldehyde (ketone) imine and application thereof in wind power blade coating

Technical Field

The wind power blade coating is essentially an anti-corrosion protective coating for wind power blades, and has the main functions of providing a smooth aerodynamic surface for the wind power blades so as to prevent the blades from being degraded by ultraviolet rays, moisture erosion, wind, sand, rain, fog abrasion and the like. Wind-powered electricity generation blade coating is mainly resisted two kinds of external erosion: the first is erosion from ultraviolet light; the second is erosion of sand, rain and fog, etc. The former is of chemical attack and the latter is of mechanical attack. In comparison, the latter is much more difficult to protect than the former. The wind power industry belongs to an emerging industry, and people are still immature in understanding and preventing the erosion mechanism of wind, sand, rain and fog on wind power blades, so that a plurality of problems to be solved are still needed.

The wind turbine generator system is generally arranged in a wind and sand enrichment area, the running environment is bad, and the blades are required to be corroded by friction of wind power and impact of sand grains, salt mist and rain beads for a long time. In particular, the linear velocity of the blade running in the windward part of the front edge of the blade tip is very high, for example, the blade with the length of 70 meters can reach 80-90m/s (equivalent to 280-300 km/h). It is conceivable that the impact damage of wind sand and rain beads to the leading edge portion of the blade is extremely serious in such an environment. If the corrosion problem of the front edge of the blade is not solved in time, the power generation efficiency can be affected, and when the blade is seriously damaged, hidden danger can be brought to the safety of the wind turbine generator.

High-speed moving parts of industrial equipment such as aircraft rotors, ship propellers, etc. are also subject to strong erosion by wind and sand, fluids, but they can be maintained and serviced in a timely or periodic manner. However, once the wind power plant is in operation, maintenance or repair of the wind power plant is extremely time consuming, labor intensive and expensive. Therefore, the protective coating used for the wind power blade, especially the front edge protective coating specially applied to the front edge of the blade tip, has excellent chemical resistance, and also has excellent wind sand resistance and rain fog erosion resistance.

The wind power blade front edge protective coating is taken as a special protective measure of the blade front edge part, and a method of applying a front edge protective film is adopted in the current practice. The protective film is a PTU transparent film, and is required to be manually stuck, so that the process requirement is very strict. However, in the operation process of the protective film, phenomena such as foaming, edge rolling, weathering and displacement of the protective film at the blade tip and the like often occur. In recent decades, two-component wind power blade leading edge protective coatings have been concerned and used in the industry, and particularly two-component polyurea coatings are more and more important, and patent literature reports are particularly high.

CN115678396 reports a low surface energy two-component polyurea coating for wind power blades, which is mainly characterized by amino terminated polyether and isocyanate modified by fluorine-containing polyether polyol. However, the amine terminated polyether terminated by primary amine has too high activity, so that the curing speed of the two-component gel is too high, and it is difficult to obtain a uniform and smooth protective coating on the surface of the wind turbine blade.

CN106068309 reports a two-component polyurea coating for wind turbine blades featuring polyaspartic acid esters and a specific ester, which is said to improve the resistance of the coating to rain erosion and solid particle erosion in the polyurea coating composition. However, this particular ester belongs in one embodiment of the patent to aromatic esters, which can adversely affect the ageing resistance of the coating.

CN105992785 reports a two-component polyurea coating for wind turbine blades, which is mainly characterized by polyaspartic acid ester and polycarbonate diol. However, the compatibility of the polycarbonate diol and polyaspartate is not good, and more importantly, the reactivity of hydroxyl groups and amino groups with aliphatic isocyanate is greatly different, so that the reaction speed of the polycarbonate diol and the isocyanate curing agent is asynchronous, the crosslinking curing speed and degree of the polycarbonate diol are affected, and finally, the overall strength of the coating is insufficient.

WO2020260578 reports a two-component polyurea coating specially used for the front edge protective coating of wind power blades, which is mainly characterized in that the resin component consists of polyether polyaspartate with two functionalities or a mixture of the polyether polyaspartate and aliphatic polyaspartate. Compared with common pure aliphatic asparagus, the difunctional polyether asparagus can obviously improve the extensibility or viscoelasticity of the coating. However, sufficient cohesive strength and elastic modulus are more desirable as a leading edge protective coating, and polyurea with only such a two-functional polyalkoxyether structure is not satisfactory.

CN115637100 reports a solvent-free rain erosion resistant wind power blade coating, which is mainly characterized in that a mixture of low molecular weight two-functionality amine terminated polyether and polytetramethylene ether glycol bis-P-aminobenzoate (P1000) is subjected to michael addition to obtain an aspartic ester structure of an amino-containing compound. The purpose of this patent was to improve the insufficient rigidity of the difunctional amine terminated polyether, but the aromatic hydrocarbon groups at both ends of P1000 would affect the ageing resistance of the coating.

It is known that, unlike the two-functional structure, the trifunctional amine-terminated polyether has a special function of promoting the aggregation and separation of the soft segment phase region and the hard segment phase region, respectively, in the crosslinked polymer network, so that it can remarkably improve the rebound resilience, tensile strength, tear strength and anti-friction properties of the polymer. However, the common trifunctional amine-terminated polyether contains three primary amino groups, has extremely high reactivity, and cannot be used in common two-component construction processes (such as air spraying, brushing, scraping and the like). Meanwhile, the trifunctional amine-terminated polyether has three primary amino groups, which cannot be completely converted into secondary amino groups through Michael addition as in the case of the difunctional primary amino compound, so that the activity is reduced and the trifunctional amine-terminated polyether is convenient to use, because the steric hindrance is too large during the addition of the three primary amino groups, and the reaction cannot be carried out to the bottom. Thus, for many years, trifunctional amine-terminated polyethers, while having many advantages, have often been bundled into a pavilion due to inconvenient use in terms of process performance.

WO2014151307 reports a process for preparing polyether aspartates using trifunctional amino-terminated polyethers. One of the methods provided in this patent is to simultaneously Michael add three primary amino groups to diethyl maleate, but no conversion data is provided in the patent. In the second method, only one primary amino group is subjected to Michael addition with diethyl maleate, and the other two primary amino groups are left in the molecular structure. In fact, three primary amino groups of method one are difficult to be completely converted into secondary amino groups due to the large steric hindrance effect, and thus the remaining primary amino groups still affect the reactivity of the product. It can be seen that this patent does not allow for the complete secondary amination of trifunctional amine-terminated polyethers. On the other hand, this patent does not mention the effect of trifunctional polyether aspartate on the performance of two-component asparaguste coatings, nor does it mention or suggest the use of such coatings on wind turbine blade coatings, including leading edge protective coatings, other than the effect of the different formulations on the drying speed of the coating.

The above reports are insufficient to solve the problems faced by wind blade paints.

Disclosure of Invention

The invention aims to provide a trifunctional polyether type aspartic ester structure and a synthetic method thereof, and the resin is used for a two-component asparaguse coating, so that the resin can meet the practical use requirements of wind power blade coatings, particularly front edge protection coatings.

The invention firstly relates to polyether aspartate containing aldehyde (ketone) imine, which has the following structural characteristics (formula 1):

Wherein R1 and R2 are respectively C1-C4 alkyl, and can be the same or different; r3 is C1-C10 aliphatic alkyl; r4 is hydrogen or C1-C10 aliphatic alkyl; and x, y and z are natural numbers of 1-5 respectively.

The invention also relates to a method for synthesizing polyether aspartate containing aldehyde (ketone) imine (formula 1), which is characterized in that:

1. One primary amino group in the trifunctional amine-terminated polyether is first blocked with an aldehyde (ketone) compound.

2. Then Michael addition is carried out with an unsaturated dicarboxylic acid ester.

The method comprises the following steps: the synthesis method of the polyether aspartate containing aldehyde (ketone) imino group comprises the following two steps:

In the first step, small molecule aldehyde (ketone) compound and trifunctional amino-terminated polyether are condensed to obtain an aldehyde (ketone) imine group, wherein the molar ratio of the aldehyde (ketone) compound to the amino-terminated polyether is 1:1, and the reaction process is as follows

Formula 2:

wherein R3, R4, and x, y, and z are as defined above for formula 1.

Secondly, carrying out Michael addition reaction on the product in the formula 2 and unsaturated dicarboxylic acid ester to obtain polyether aspartic acid ester containing aldehyde (ketone) imino groups, wherein the molar ratio of the product in the formula 2 to the unsaturated dicarboxylic acid ester is 1:2, and the reaction process is shown as the formula 3:

wherein R1, R2, R3, R4 and x, y, z are as defined above for formula 1.

In said first step, the condensation reaction of the small molecule aldehyde (ketone) compound with the trifunctional amine-terminated polyether can be carried out according to synthetic methods common in the art for aldehyde (ketone) imines, such as: firstly, reacting amine-terminated polyether with aldehyde (ketone) compound for 2-3 hours at the temperature of 40-50 ℃, then raising the temperature to 80-90 ℃ and refluxing and dehydrating with a water carrying agent until the water yield reaches a theoretical value, then raising the temperature to 90-110 ℃, and cooling after removing the water carrying agent by vacuum to obtain the product of the formula 2.

In said second step, the addition reaction of the product of formula 2 with the unsaturated dicarboxylic acid ester may be carried out according to the methods usual in the art of michael addition reactions; for example: the unsaturated dicarboxylic acid ester is slowly dripped into the product of the formula 2, and the temperature is controlled within the range of 50-60 ℃. After the dripping is finished, heating to 60 ℃ for heat preservation reaction for 10-12 hours, finally heating to 100 ℃ for vacuumizing for 1 hour to remove unreacted monomers, and cooling to obtain the product of the formula 3, namely the aldehyde (ketone) -containing iminopolyether aspartate.

The trifunctional amine-terminated polyether may be a trifunctional amine-terminated polyether having a molecular weight of 200-800, preferably 400, such as commercially available amine-terminated polyether T-403.

The small molecule aldehyde (ketone) compound containing carbon radicals comprises, but is not limited to, acetaldehyde, propionaldehyde, butyraldehyde, isobutyraldehyde, acetone, butanone, 2-pentanone, 3-pentanone, 2-hexanone, 3-hexanone and the like, and 4-methyl-2-pentanone. Preference is given to using isobutyl ketone or 4-methyl-2-pentanone.

The unsaturated dicarboxylic acid esters may be, but are not limited to, dimethyl maleate, diethyl maleate, dibutyl maleate, dimethyl fumarate, diethyl fumarate and dibutyl fumarate, which may be used alone or in any ratio. Preferably diethyl maleate is used.

The invention further relates to a two-component asparagus coating containing aldehyde (ketone) imine polyether type aspartic ester, which is characterized in that: the resin is prepared by the joint reaction of resin components and curing agent components:

And (3) a resin component: is composed of at least one aldehyde (ketone) -containing iminopolyether polyaspartate and at least one aliphatic polyaspartate.

Wherein: the aldehyde (ketone) -containing iminopolyether polyaspartate has a structure as shown in formula 1, and the aliphatic polyaspartate resin has a structure as shown in formula 4:

Wherein:

r1, R2, R3 and R4 are respectively C-C4 alkyl, and can be the same or different;

x: is of the following structure (formula 5):

or may be of the following structure (formula 6):

or may also be of the following structure (formula 7):

CH2-CH2-CH2

7. The method of the invention

The aliphatic polyaspartate products containing the structures of formula 4, formula 5, formula 6 and formula 7 are commercially available, for example, from the group of AP-104, AP-105 and AP-102 of Venetian paint.

As an optimization mode, the composition (weight) ratio of the aldehyde (ketone) -imine-containing polyether polyaspartate to the aliphatic polyaspartate is 1:9-9:1, preferably 2:8-5:5.

And the curing agent comprises the following components: consists of at least one amino-terminated polyether modified aliphatic isocyanate prepolymer and at least one aliphatic isocyanate trimer;

wherein: the amino-terminated polyether modified aliphatic isocyanate prepolymer has the following structural formula (formula 8):

Wherein x, y and z are natural numbers of 0 to 6 respectively; n is a natural number such as 1,2, 3, 4, etc.; r is an aliphatic isocyanate alkylene group, including but not limited to isophorone diisocyanate (IPDI), hexamethylene Diisocyanate (HDI), hydrogenated MDI (HMDI), xylylene Diisocyanate (XDI).

The amino-terminated polyether is amino-terminated polyether with a difunctional molecular weight of 400-2000, and the preferable amount is 1000-2000. They may be used alone or in any mixture.

The aliphatic isocyanates include, but are not limited to, IPDI, HDI, HMDI and XDI, preferably IPDI and HMDI, which may be used alone or in any ratio.

The equivalent ratio of [ NCO ]/[ HN ] of the amine-terminated polyether to the aliphatic isocyanate is calculated as 2.0-5.0:1, preferably 3.5-4.5:1.

The synthesis of the amino-terminated polyether modified aliphatic isocyanate prepolymer can be carried out according to the following method: the amine-terminated polyether is slowly dripped into isocyanate under the condition of cold water bath, and the temperature is controlled to be not more than 30 ℃. And after the dripping is finished, the reaction is continued for 1 hour at a low temperature, and then the temperature is increased to 60 ℃ to continue the reaction until the NCO% content reaches the design value. Cooling to 40 ℃ and discharging to obtain a product of the formula 8, namely the amino-terminated polyether modified aliphatic isocyanate prepolymer.

The aliphatic isocyanate trimer has the following structure (formula 9):

wherein R is an alkylene group of HDI or IPDI.

The trimer of aliphatic isocyanate comprises IPDI trisome or HDI trimer, such as commercially available Desmodur N3300, N3600, N75, etc., preferably HDI trimer.

The curing agent component consists of at least one amino-terminated polyether modified aliphatic isocyanate prepolymer and at least one aliphatic isocyanate trimer, wherein the composition (weight) ratio of the amino-terminated polyether modified aliphatic isocyanate prepolymer to the aliphatic isocyanate trimer is 4:6-9:1, preferably 6:4-8:2.

The further optimization mode is as follows:

As the coating material, the resin component may be added, as required, with fillers, coupling agents, dispersants, thixotropic agents, pigments, leveling agents, antifoaming agents, ultraviolet light absorbers, antioxidants and the like, in addition to at least one aldehyde (ketone) -containing urethane polyether type aspartyl resin and at least one aliphatic polyaspartic acid ester.

The filler can be calcium carbonate, talcum powder, titanium dioxide, silicon micropowder, barium sulfate and the like. They may be used alone or in any ratio. The total amount of filler used may be 20-60% by weight based on the total weight of the resin component.

Preferably 25-45%.

The coupling agent can be KH-550, KH-560, KH-602, etc. The coupling agent is used in an amount of 0.1% -1% of the total weight of the pigment and filler in the resin component. Preferably 0.1 to 0.5% is used.

The dispersing agent can be BYK-110, BYK-163, BYK-180 and the like. The amount of dispersant used is based on the supplier's recommendations.

The thixotropic agent may be fumed silica, kaolin, attapulgite, etc. The thixotropic agent can be used alone or in any ratio. The total amount of thixotropic agent used is 0-20%, preferably 0-15%.

The pigment can be carbon black, titanium pigment, iron oxide yellow, iron oxide red, phthalocyanine blue and the like. The amount of pigment used depends on the color requirements of the paint.

The leveling agent can be BYK-333, BYK-354 and the like. The leveling agent can be used alone or in any ratio, and the use amount is according to the proposal of suppliers.

The defoamer can be BYK-066N, BYK-085, etc. The defoamer can be used alone or in any ratio, and the use amount is according to the proposal of suppliers.

The ultraviolet light absorbers may be 1130, 770, 292, etc. The ultraviolet light absorber can be used alone or in any ratio, and the use amount is according to the proposal of suppliers.

The antioxidant can be 1010, B225, 330, etc. The antioxidants may be used alone or in any ratio, depending on the supplier's recommendations.

The preparation method of the resin component in the double-component asparaguse coating containing aldehyde (ketone) imine polyether type aspartic ester can be carried out according to the following sequence: 1 firstly, proportionally weighing the aldehyde (ketone) -containing iminopolyether polyaspartic acid ester and the aliphatic polyaspartic acid ester, and uniformly mixing and stirring in a container.

2, Adding metered coupling agent, dispersing agent, leveling agent, defoamer, ultraviolet absorber, antioxidant and other auxiliary agents, and fully and uniformly stirring.

And 3, adding filler, thixotropic agent, color paste and the like, fully and uniformly stirring, and then, increasing the stirring speed (2000 rpm) to disperse at a high speed for 30 minutes to obtain the resin component.

In the curing agent component, besides at least one amino-terminated polyether modified aliphatic isocyanate prepolymer and at least one aliphatic isocyanate trimer, a proper amount of reactive diluent and plasticizer can be added according to viscosity requirements, wherein the reactive diluent can be propylene carbonate, gamma-butyrolactone and the like, and the plasticizer can be dioctyl phthalate, acetyl tributyl citrate and the like. They may be used alone or in any ratio.

The preparation method of the curing agent component can be carried out according to the following sequence:

1 first, a metered amount of an aliphatic isocyanate prepolymer modified with an amine-terminated polyether is weighed and poured into a container.

2 Adding a metered amount of reactive diluent or plasticizer and stirring uniformly.

And 3, adding the metered isocyanate trimer and uniformly stirring to obtain the curing agent component.

The invention relates to a double-component asparagus coating containing aldehyde (ketone) imine polyether type aspartic ester for a wind power blade front edge protective coating, which is a solvent-free system, is suitable for manual blade coating construction, and the blade coating area is arranged on two sides of a windward part of one third of the length of the tip end of a wind power blade. The viscosity of the component A (resin) and the viscosity of the component B (curing agent) of the coating are 5000-6000mPa.s and 25000-55000 mPa.s respectively, and the mixing ratio of the components by weight is A:B=1:1.0-1.6.

The specific construction method and the requirements are as follows:

1 the measured A, B components are weighed according to the mixing ratio.

And 2, mixing A, B components, fully and uniformly stirring by using a painter knife, and avoiding air bubbles from being wrapped in the materials as much as possible.

And 3, uniformly scraping the paint on the cleaned part to be painted, and controlling the wet thickness to be 150-200 mu m. Wait for 60 minutes wet film to dry and form and then scrape the coating for the second time. The mixed paint must be used within 1 hour.

4 Repeating the steps 1 and 2, and in the first coating layer, carrying out blade coating for the second time, controlling the thickness of the wet film to be 150-200 mu m (ensuring the total thickness of the dry film to be more than 300 mu m), and keeping the surface of the coating layer uniform and smooth without flaws. The mixed paint must be used within 1 hour.

And 5, at the ambient temperature, the coating can be completely cured after two hours in summer, and the blade can move. The coating can be fully cured and the blade can be moved in the winter requiring 3 hours.

Innovative of

1. The first innovation point of the invention is that a small molecular aldehyde (ketone) compound is used for closing one primary amino group in trifunctional amino-terminated polyether, so that steric hindrance space is reduced for subsequent further Michael addition reaction, and polyether aspartic ester with controllable reaction activity and trifunctional, namely the compound of formula 1, can be successfully obtained.

2. The second innovation point of the patent of the invention is to apply the compound of formula 1 to a two-component asparaguse coating

3. The third innovation of the present patent is the incorporation of a difunctional amine-terminated polyether into an aliphatic isocyanate prepolymer. In the current polyurethane/polyurea technology, in order to improve the crosslinking performance of the curing agent, hydroxyl group-containing polyesters, tetrahydrofuran polyethers, polycarbonate diols, or the like are generally used as the soft segment of the curing agent, but the resulting curing agent is substantially urethane-modified. The invention adopts amino-terminated polyether as a soft chain segment to obtain an ureido modified curing agent, so that all crosslinking points in a polymer crosslinking network are completely composed of urea bonds, the phase separation of a hard segment phase region and a soft satin phase region is promoted to the greatest extent, and the elastomer characteristic of a polymer coating is improved.

The beneficial effects are that:

1. Overall excellent material properties: the front edge protective coating specially applied to the front edge of the blade tip has excellent chemical resistance, and also has excellent wind sand resistance and rain fog resistance for a long time. Therefore, the wind power blade coating is different from the common coating in that the wind power blade coating is required to have the strict corrosion resistance, such as damp heat resistance (2000 hr), aging resistance (2500 hr), salt fog resistance (2000 hr), and mechanical properties, such as rain erosion resistance (20 hr), elongation at break (300%), wear resistance (60 mg) and the like, so that the wind power blade coating needs special raw material components and formulas. Based on the three innovation points, the aldehyde (ketone) -imine-containing polyether type aspen polyurea coating provided by the invention meets the corrosion resistance requirements, and has the performance characteristics of an elastomer in a true sense, namely the capability of fully absorbing high-speed impact such as wind sand, rain beads and the like, so that the performance requirements of wind power blade coatings including a front edge protective coating are well met.

2. Convenient and practical construction performance: the curing reaction process of the two-component coating comprises the following steps: firstly, two secondary amino groups in the formula 1 react with isocyanate groups, the reaction activity of the step is equivalent to that of common aliphatic polyaspartic ester, and the speed is controllable. The aldehyde (ketone) imine of formula 1 then releases a primary amino group upon absorption of moisture in the air, which then reacts rapidly with the isocyanate. The aldehyde (ketone) imine plays a role in latent catalysis and curing, so that the curing speed of the two-component polyurea system is equivalent to that of a common two-component polyurethane or asparagi polyurea system. Such process characteristics can be used for both mechanical spraying and hand brushing and knife coating.

Drawings

FIG. 1 is an infrared spectrum of the product of the first step of example 1;

FIG. 2 is an infrared spectrum of the product of the second step of example 1;

FIG. 3 is an infrared spectrum of the product of the first step of example 2;

FIG. 4 an infrared spectrum of the product of the second step of example 2.

Detailed Description

The main raw materials used in this example are listed in table 1.

Table 1 list of main raw material information

Sequence number	Name of product	Code number	Suppliers (suppliers)
				1	Trifunctional amine terminated polyethers	T-403	Yangzhou Chenhua
2	Difunctional amine terminated polyethers	D-2000	Yangzhou Chenhua
				3	Difunctional amine terminated polyethers	D-1000	Yangzhou Chenhua
4	Isobutyraldehyde	IBA	Commercial chemical reagents
				5	4-Methyl-2-pentanone	MIBK	Commercial chemical reagents
6	Maleic acid diethyl ester	DM	Shanghai Gao Ming chemical Co., ltd
				7	Aliphatic diisocyanates	HMDI	Science creation
8	HDI trimer	3300	Science creation
				9	Aliphatic polyaspartic esters	AP-104	Paint for maintaining fresh
10	Aliphatic polyaspartic esters	AP-105	Paint for maintaining fresh
				11	Polyether polyaspartic acid ester	2000S	Paint for maintaining fresh

EXAMPLE 1 preparation of aldimine-containing polyether aspartate

First step

To a 2000ml four-necked flask equipped with a stirrer, a thermometer, a nitrogen gas conduit, a reflux tube and a constant pressure dropping funnel were charged 400 g (1 mol) of T-403 and 250 g of cyclohexane, and the air in the flask was replaced with nitrogen gas by vacuum and kept purged with nitrogen gas. 72.1 g (1 mol) of IBA was slowly added dropwise via a constant pressure funnel with stirring, and the temperature of the reaction mass in the flask was controlled in the range of 25-35℃with a cold water bath, and the addition time was controlled to about 1 hour. After the dripping is finished, the temperature is raised to 50 ℃ and the reaction is kept for 3 hours, then an oil-water separator is added under a reflux pipe, the temperature is raised to 90 ℃, and the water is separated by reflux until the water yield reaches the theoretical value. Then heating to 100 ℃ and removing cyclohexane under vacuum. Cooling to room temperature for standby. The infrared spectrogram is shown in the attached figure 1.

As can be seen from FIG. 1, a very pronounced aldimine-C=N characteristic peak appears at 1668.12cm ^-1, while the carbonyl-C=O peak near 1731cm ^-1 has completely disappeared, whereas the telescoping vibration peak near 1106.94cm ^-1 is a carbon oxide ether linkage-C-O-C-. From this, it can be stated that the aldimine species were synthesized from T-403 and IBM.

Second step

Stirring and nitrogen are started, 344,4 g (2 mol) of DM is slowly dripped into the product of the first step, the temperature of the material is controlled between 50 and 60 ℃, and the dripping speed is controlled to ensure that DM is dripped out in about 1 hour. Then reacting for 10-18 hours at the constant temperature of 60 ℃, and cooling to the room temperature to obtain the polyether type aspartic ester containing aldimine, which is marked as AEA-400. The theoretical calculated amino equivalent is 272, and the infrared spectrogram is shown in the attached figure 2.

From fig. 2, it can be seen that the double bond-c=c characteristic peak of DM at 1644cm ^-1 has completely disappeared, and it can be explained that the remaining primary amino group of T-403 has completely reacted with DM to convert to a secondary amino group.

EXAMPLE 2 preparation of ketimine-containing polyether aspartate

First step

To a 2000ml four-necked flask equipped with a stirrer, a thermometer, a nitrogen gas conduit, a reflux tube and a constant pressure dropping funnel were charged 400 g (1 mol) of T-403 and 250 g of cyclohexane, and the air in the flask was replaced with nitrogen gas by vacuum and kept purged with nitrogen gas. 100.2 g (1 mol) of MIBK was slowly added dropwise through a constant pressure funnel with stirring, and the temperature of the reaction mass in the flask was controlled in the range of 25-35℃with a cold water bath, and the addition time was controlled to about 1 hour. After the dripping is finished, the temperature is raised to 50 ℃ and the reaction is kept for 3 hours, then an oil-water separator is added under a reflux pipe, the temperature is raised to 90 ℃, and the water is separated by reflux until the water yield reaches the theoretical value. Then heating to 100 ℃ and removing cyclohexane under vacuum. Cooling to room temperature for standby. The infrared spectrogram is shown in the attached figure 3.

As can be seen from FIG. 3, a very pronounced ketimine-C=N characteristic kinetic peak appears at 1658.48cm ^-1, while the carbonyl-C=O peak near 1731cm ^-1 has substantially disappeared, while the telescoping vibration peak near 1105.01cm ^-1 is the carbon oxide ether linkage-C-O-C-. It can be stated that the ketimine species were synthesized from T-403 and MIBK.

Second step

Stirring and nitrogen are started, 344,4 g (2 mol) of DM is slowly dripped into the product of the first step, the temperature of the material is controlled between 50 and 60 ℃, and the dripping speed is controlled to ensure that DM is dripped out in about 1 hour. Then reacting for 10-12 hours at the constant temperature of 60 ℃, and cooling to the room temperature to obtain the polyether aspartate containing ketimine, which is marked as KEA-400. The theoretical amino equivalent is 282. The infrared spectrum is shown in the attached figure 4.

From fig. 4, it can be seen that the double bond-c=c characteristic peak of DM at 1644cm ^-1 has completely disappeared, and it can be explained that the remaining primary amino group of T-403 has completely reacted with DM to convert to a secondary amino group.

EXAMPLE 3 preparation of amino-terminated polyether modified aliphatic isocyanate prepolymer

To a 1000ml four-necked flask equipped with a stirrer, a thermometer, a nitrogen gas introduction tube, a reflux tube and a constant pressure dropping funnel, 262.3 g (1 mol) of HMDI was charged, and the air in the flask was replaced with nitrogen gas by vacuum and kept purged with nitrogen gas. 513.9 g (0.26 mol) of D-2000 was slowly added dropwise via a constant pressure funnel while stirring, the temperature of the reaction mass in the flask was controlled in the range of 25-35℃with a cold water bath, and the addition time was controlled to about 1 hour. After the dripping is finished, the reaction is carried out for 1 hour at 40 ℃, then the temperature is raised to 60 ℃ for reaction for about 2 hours until the NCO percent content reaches 8.0 percent. Cooling to 40 ℃ to obtain the amino-terminated polyether modified aliphatic isocyanate prepolymer, and measuring the viscosity to 30117 mPa.s.

EXAMPLE 4 preparation of amino-terminated polyether modified aliphatic isocyanate prepolymer

To a 1000ml four-necked flask equipped with a stirrer, a thermometer, a nitrogen gas introduction tube, a reflux tube and a constant pressure dropping funnel, 262.3 g (1 mol) of HMDI was charged, and the air in the flask was replaced with nitrogen gas by vacuum and kept purged with nitrogen gas. 326 g (0.16 mol) of D-2000 was slowly added dropwise through a constant pressure funnel while stirring, the temperature of the reaction mass in the flask was controlled in the range of 25 to 35℃by a cold water bath, and the addition time was controlled to about 1 hour. After the completion of the dropwise addition, the reaction was carried out at 35℃for 1 hour. Then 139.7 g (0.14 mol) of D-1000 is continuously dripped, the temperature is controlled within the range of 25-35 ℃, the dripping time is controlled to be about 0.5, the temperature is raised to 40 ℃ after the dripping is finished and the reaction is carried out for 1 hour at constant temperature, then the temperature is raised to 60 ℃ and the reaction is carried out for about 2 hours until the NCO percent content reaches 8.0 percent. Cooling to 40 ℃ to obtain the amino-terminated polyether modified aliphatic isocyanate prepolymer, and measuring the viscosity to 10291 mPa.s.

Example 5 preparation of two-component polyurea coating resin component A1 containing aldimine polyether aspartate 1 first, the raw material components with the formula numbers A1 of 3-9 in Table 2 are mixed uniformly and dispersed at high speed (> 2000 rpm) for 20min. And 2, sequentially adding the raw material components with the serial numbers of 10-15 into the mixed solution, fully and uniformly stirring, and grinding the mixture to the fineness of less than or equal to 25 mu m by using a sand mill to prepare the gray color paste containing the resin component.

And 3, sequentially adding the raw material components with the serial numbers of 1-2 and 16-19 into the gray color paste, stirring and dispersing for 30 minutes at a high speed (2000 rpm) to obtain a resin component A1, and measuring the viscosity to be 2927 mPa.s.

Example 6 preparation of a two-component polyurea coating resin component A2 containing a ketimine polyether-type aspartate resin component A2 was prepared according to the formulation of A2 in Table 2, and the complete procedure of example 5 was followed to obtain resin component A2.

Example 7 preparation of a two-component polyurea coating resin component A3 containing an aldehyde, ketimine polyether aspartate resin component A3 was prepared according to the formulation of A3 in Table 2, following the complete procedure of example 5, to obtain resin component A3.

Example 8 preparation of two-component polyurea coating resin component A4 containing aldimine polyether aspartate resin component A4 was prepared according to the formulation of A4 in Table 2, following the complete procedure of example 5.

Example 9 preparation of a two-component polyurea coating resin component A5 containing a ketimine polyether-type aspartate resin component A5 was prepared according to the formulation of A5 in Table 2, and the complete procedure of example 5 was followed to obtain resin component A5.

Example 10 preparation of a two-component polyurea coating curative component B1 containing an aldehyde (ketone) imine polyether aspartate 18 parts of the amino terminated polyether modified aliphatic isocyanate prepolymer obtained in example 3 were weighed.

2 Parts of HDI trimer 3300 are weighed out.

And 3, uniformly mixing the two to obtain the curing agent component B1. The average viscosity was found to be 35348 mPas and the average NCO content was found to be 10.6%.

Example 11 preparation of a two-component polyurea coating curative component B2 containing an aldehyde (ketone) imine polyether aspartate 18 parts of the amino terminated polyether modified aliphatic isocyanate prepolymer obtained in example 4 were weighed.

2 Parts of HDI trimer 3300 are weighed out.

And 3, uniformly mixing the two to obtain a curing agent component B2. The average viscosity was found to be 13472 mPas and the average NCO content was found to be 10.6%.

Example 12 preparation of two-component coating film test piece F1

1, Preparing a glass fiber reinforced epoxy composite test board (FR 4) in advance, wherein the specification is 75 multiplied by 150 multiplied by 10mm, repairing and filling a base surface by using putty before coating, and polishing and flattening the base surface for later use.

Test piece steel mould with the specification of 200 multiplied by 2mm is prepared in advance, and the mould release agent is coated for standby after cleaning.

And 2, weighing the components A1 and B1 according to the formula proportion of F1 in the table 3, fully stirring and uniformly mixing, and avoiding cavitation bubbles from being wrapped in the components.

3, Coating and scraping the mixed paint on the glass fiber reinforced epoxy resin composite board for 2-3 times, wherein each time is separated by 60 minutes until the accumulated thickness of the coating reaches more than 300 mu m. Ensuring the surface of the coating to be flat and smooth.

4, The mixed paint is coated and scraped in a steel die of the test piece, and the thickness of the wet film reaches 2mm. Ensuring the surface of the coating film to be flat and smooth, and no bubble exists in the film. 5, placing the scraped coating film until the coating film is completely cured to obtain a coating film test piece F1. Performance was tested after a further 7 days of standing.

Example 13-example 17 preparation of two-component film coated test pieces F2-F6

The corresponding A, B components were weighed according to the formulation proportions of F2-F6 in Table 3, and then the whole procedure of example 12 was followed to obtain coating test pieces F2-F6.

Comparative example 1 preparation of aliphatic isocyanate prepolymer modified with polycarbonate diol

To a 1000ml four-necked flask equipped with a stirrer, a thermometer, a nitrogen gas introduction tube, a reflux tube and a constant pressure dropping funnel, 262.3 g (1 mol) of HMDI was charged, and the air in the flask was replaced with nitrogen gas by vacuum and kept purged with nitrogen gas. 513.9 g (0.26 mol) of PCDL-2000 was slowly added dropwise through a constant pressure funnel while stirring, and the temperature of the reaction mixture in the flask was controlled to be 25-35℃in a cold water bath for about 1 hour. After the dripping is finished, the reaction is carried out for 1 hour at 40 ℃, then the temperature is raised to 60 ℃ for reaction for about 2 hours until the NCO percent content reaches 8.0 percent. Cooling to 40 ℃ to obtain the polycarbonate diol modified aliphatic isocyanate prepolymer, wherein the viscosity is 20640 mPa.s.

Comparative example 2 preparation of comparative example resin component AC1 was obtained by following the complete procedure of example 5 according to the formulation of AC1 in table 2.

Comparative example 3 preparation of comparative example resin component AC2 was obtained by following the complete procedure of example 5 according to the formulation of AC2 in table 2.

Comparative example 4 comparative example curative component BC1

18 Parts of the polycarbonate diol-modified aliphatic isocyanate prepolymer obtained in comparative example 1 was weighed out.

2 Parts of HDI trimer 3300 are weighed out.

And 3, uniformly mixing the three components to obtain the component BC1 of the curing agent of the comparative example. The average viscosity was measured to be 16000 mPas and the average NCO content was 8.8%.

Comparative example 5-comparative example 7 production of comparative example coating film test pieces FC1-FC3

The corresponding A, B components were weighed according to the formulation ratio of FC1-FC3 in Table 3, and then the comparative example coating test pieces FC1-FC3 were obtained by the complete procedure of example 12.

Table 2 shows the formulation comparisons of the resin components in examples 5 to 8 and comparative examples 2 to 3, and the respective components are calculated in weight units.

TABLE 2A component formulation list of different formulation compositions

Table 3 shows the proportions of the respective coating films composed of the resin components A1 to A5, AC1 to AC2 and the curing agent components B1, B2 and BC1, and the results of their main performance tests, each of the corresponding coating films being represented by F1 to F6 and FC1 to FC3, respectively. All the components are calculated in weight units.

Table 3A list of the main properties of the coating compositions in examples and comparative examples

Note: racket referring to certain domestic wind power blade manufacturer

From the results shown in Table 3, it is clear that only the coating obtained by the present invention can meet the corresponding technical requirements, but the comparative examples cannot meet the corresponding requirements.

Claims

1. An aldehyde (ketone) -imine-containing polyether aspartate having the structure shown in formula I: :

Wherein R1 and R2 are respectively C1-C4 alkyl, which can be the same or different; r3 is C1-C10 aliphatic alkyl; r4 is hydrogen or C1-C10 aliphatic alkyl; and x, y and z are natural numbers of 1-5 respectively.

2. The method for synthesizing an aldehyde (ketone) -imine-containing polyether aspartic ester according to claim 1, wherein the method is realized by the following steps:

Firstly, condensing a small-molecule aldehyde (ketone) compound and trifunctional amino-terminated polyether to obtain an aldehyde (ketone) imine group, wherein the molar ratio of the aldehyde (ketone) compound to the amino-terminated polyether is 1:1, and the reaction process is shown as formula 2:

Wherein R1 and R2 are respectively C1-C4 alkyl, and are the same or different; r3 is C1-C10 aliphatic alkyl; r4 is hydrogen or C1-C10 aliphatic alkyl; and x, y and z are natural numbers of 1-5 respectively.

3. The method for synthesizing an aldehyde (ketone) -imine-containing polyether aspartic ester according to claim 1,

In the first step, firstly, the trifunctional amine-terminated polyether and aldehyde (ketone) compound react for 2-3 hours at the temperature of 40-50 ℃, then the temperature is increased to 80-90 ℃ and the water is used for refluxing and dehydrating until the water yield reaches a theoretical value, then the temperature is increased to 90-110 ℃, and the product of the formula 2 is obtained after the water is removed by vacuum and cooled;

In the second step, firstly, slowly dripping unsaturated dicarboxylic acid ester into the product of the formula 2, and controlling the temperature within the range of 50-60 ℃; after the dripping is finished, heating to 60 ℃ for heat preservation reaction for 10-12 hours, finally heating to 100 ℃ for vacuumizing for 1 hour to remove unreacted monomers, and cooling to obtain a product of the formula 3, namely the aldehyde (ketone) -containing iminopolyether aspartate;

The trifunctional amine-terminated polyether is trifunctional amine-terminated polyether with molecular weight of 200-800; the small molecule aldehyde (ketone) compound containing the carbon group comprises acetaldehyde, propionaldehyde, butyraldehyde, isobutyraldehyde, acetone, butanone, 2-pentanone, 3-pentanone, 2-hexanone, 3-hexanone and the like, and 4-methyl-2-pentanone;

the unsaturated dicarboxylic acid esters include dimethyl maleate, diethyl maleate, dibutyl maleate, dimethyl fumarate, diethyl fumarate and dibutyl fumarate, which can be used alone or in any ratio.

4. A two-component asparate polyurea coating comprising an aldehyde (ketone) imine polyether aspartate, characterized by: comprises a resin component and a curing agent component:

(1) And (3) a resin component: consisting of at least one aldehyde (ketone) -containing iminopolyether polyaspartate according to claim 1 or 2 and at least one aliphatic polyaspartate;

Wherein:

x: is formula 5:

Or formula 6:

or formula 7:

-CH₂-CH₂-CH₂-CH₂-CH₂-CH₂-

7. The method of the invention

The weight ratio of the aldehyde (ketone) -containing imine polyether polyaspartate to the aliphatic polyaspartate is 1:9-9:1;

(2) And the curing agent comprises the following components: consists of at least one amino-terminated polyether modified aliphatic isocyanate prepolymer and at least one aliphatic isocyanate trimer;

wherein: the amine-terminated polyether modified aliphatic isocyanate prepolymer has a structure shown in formula 8:

Wherein x, y and z are natural numbers of 0 to 6 respectively; n is a natural number such as 1,2, 3, 4, etc.; r is aliphatic isocyanate alkylene;

The amino-terminated polyether modified aliphatic isocyanate prepolymer is obtained by the following steps: slowly dripping amine-terminated polyether into isocyanate under cold water bath, and controlling the temperature to be not more than 30 ℃; continuously reacting for 1 hour at low temperature after the dripping is finished, and then heating to 60 ℃ to continuously react until the NCO% content reaches a design value; cooling to 40 ℃ and discharging to obtain a product of formula 8, namely an amino-terminated polyether modified aliphatic isocyanate prepolymer; wherein the equivalent ratio of [ NCO ]/[ HN ] of the amine-terminated polyether to the aliphatic isocyanate is 2.0-5.0:1, and the amine-terminated polyether is the amine-terminated polyether with the molecular weight of 400-2000 of two functionalities which is used singly or mixed according to any proportion; aliphatic isocyanates including IPDI, HDI, HMDI and XDI, used alone or in any ratio;

the aliphatic isocyanate trimer has a structure shown in 9

Wherein R is an alkylene group of HDI or IPDI;

Wherein the weight ratio of the amino-terminated polyether modified aliphatic isocyanate prepolymer to the aliphatic isocyanate trimer is 4:6-9:1.

5. The two-component asparate coating comprising an aldehyde (ketone) imine polyether aspartate according to claim 4, wherein:

(1) The resin component comprises at least one aldehyde (ketone) -containing polyurethane polyether type aspartyl resin and at least one aliphatic polyaspartic acid ester, and filler, coupling agent, dispersing agent, thixotropic agent, pigment, flatting agent, defoamer, ultraviolet light absorber and antioxidant are added according to the need;

(2) In addition to the at least one amine-terminated polyether modified aliphatic isocyanate prepolymer and the at least one aliphatic isocyanate trimer, a suitable amount of reactive diluent and plasticizer may be added to the curative component as required by viscosity.

6. The two-component asparate-polyurea coating comprising an aldehyde (ketone) imine polyether aspartate according to claim 5, wherein:

(1) In the resin component, the resin component is prepared from the following components,

The filler is calcium carbonate, talcum powder, titanium dioxide, silicon micropowder and barium sulfate which are used singly or mixed according to any proportion, and the total amount of the filler is 20-60% of the total weight of the resin component;

The coupling agent is KH-550, KH-560 or KH-602, and the use amount of the coupling agent is 0.1% -1% of the total weight of pigment and filler in the resin component;

the dispersing agent is BYK-110, BYK-163 or BYK-180;

The thixotropic agent can be fumed silica, kaolin or attapulgite, and is used singly or mixed according to any proportion, and the use amount of the thixotropic agent is 0-20% of the total weight of the resin component;

the pigment is carbon black, titanium dioxide, iron oxide yellow, iron oxide red or phthalocyanine blue;

The leveling agent is BYK-333 or BYK-354; the leveling agents are used singly or mixed according to any proportion;

The defoamer is BYK-066N or BYK-085, and is used singly or mixed according to any proportion;

The ultraviolet light absorber is 1130, 770 or 292, and the ultraviolet light absorber is used singly or mixed according to any proportion;

The antioxidant is 1010, B225 or 330; the antioxidants are used singly or mixed according to any proportion;

(2) In the curing agent component

Wherein the reactive diluent is propylene carbonate or gamma-butyrolactone, which are used singly or mixed according to any proportion; the plasticizer is dioctyl phthalate or acetyl tributyl citrate, which is used alone or mixed according to any proportion.

7. The two-component asparate-polyurea coating comprising an aldehyde (ketone) imine polyether aspartate according to claim 5 or 6, wherein:

(1) The preparation method of the resin component can be obtained by the following steps:

Firstly, weighing aldehyde (ketone) -containing iminopolyether polyaspartic acid ester and aliphatic polyaspartic acid ester according to a proportion, and uniformly mixing and stirring in a container;

Secondly, adding a metered coupling agent, a dispersing agent, a leveling agent, a defoaming agent, an ultraviolet light absorber and an antioxidant, and fully and uniformly stirring;

Finally, adding filler, thixotropic agent, color paste and the like, fully and uniformly stirring, and then, increasing the stirring speed (2000 rpm) to disperse at a high speed for 30 minutes to obtain a resin component;

(2) The preparation method of the curing agent component can be carried out according to the following sequence:

Firstly, weighing and pouring metered amino-terminated polyether modified aliphatic isocyanate prepolymer into a container;

secondly, adding a metered reactive diluent or plasticizer and uniformly stirring;

and finally adding the metered isocyanate trimer and uniformly stirring to obtain the curing agent component.

8. The two-component asparate-polyurea coating comprising an aldehyde (ketone) imine polyether aspartate according to any one of claims 4 to 6, wherein:

the viscosity of the resin component is 5000-6000mPa.s, the viscosity of the curing agent component is 25000-55000 mPa.s, and the mixing weight ratio of the resin component to the curing agent component is 1:1.0-1.6.

9. The use of a two-component asparaguse coating containing an aldehyde (ketone) imine polyether aspartate according to claim 8 on wind blades, characterized in that:

Step 1, respectively weighing the metered resin components and the curing agent components according to the mixing ratio;

step 2, mixing the resin component and the curing agent component and fully and uniformly stirring;

Step 3, uniformly scraping the paint on the cleaned part to be coated, and controlling the wet thickness to be 150-200 mu m; waiting for 60 minutes to dry the wet film preliminarily to form a second-time coating which can be coated again; the mixed paint needs to be used within 1 hour;

Step 4, repeating the steps 1 and 2, carrying out blade coating on the coating for the second time in the first time, controlling the thickness of the wet film to be 150-200 mu m, ensuring the total thickness of the dry film to be more than 300 mu m, and keeping the surface of the coating uniform and smooth without flaws; the mixed paint needs to be used within 1 hour;

step 5, at the ambient temperature, the coating can be completely cured after two hours in summer, and the blade can move; the coating can be fully cured and the blade can be moved in the winter requiring 3 hours.