CN112760000B

CN112760000B - Anti-icing coating easy to remove ice at low temperature and preparation method thereof

Info

Publication number: CN112760000B
Application number: CN202110174372.6A
Authority: CN
Inventors: 赵玮; 许建华
Original assignee: Hangzhou Wanguan Technology Co ltd
Current assignee: Hangzhou Wanguan Technology Co ltd
Priority date: 2021-02-07
Filing date: 2021-02-07
Publication date: 2022-01-04
Anticipated expiration: 2041-02-07
Also published as: CN112760000A

Abstract

The invention relates to an anti-icing coating easy to remove icing at low temperature, which comprises a component A and a component B, wherein the component A comprises the following raw materials in parts by weight: 60-70 parts of fluorine-silicon composite resin, 0.5-1 part of nano-scale polytetrafluoroethylene, 3-8 parts of castor oil, 6-10 parts of double-end vinyl silicone oil, 6-10 parts of organic silicon modified paraffin and 10-17 parts of first diluent; the component B comprises the following raw materials in parts by weight: 7-10 parts of curing agent and 30-60 parts of second diluent. According to the invention, the castor oil, the double-end vinyl silicone oil and the organic silicon modified paraffin are introduced into the silicon-fluorine composite resin, the compatibility of the components is good, the synergistic effect exists, the stress difference between the hard ice coating and the flexible coating in a low-temperature environment is very large, and the ice coating can be easily removed under the low-temperature condition. The nano tetrafluoroethylene wax is prepared into certain slurry, and the slurry is distributed on the surface of the coating in a hemispherical or microspherical manner, so that the whole coating has an extremely low friction coefficient, and the ice coating prevention effect at low temperature can be realized.

Description

Anti-icing coating easy to remove ice at low temperature and preparation method thereof

Technical Field

The invention belongs to the technical field of anti-icing coatings, and particularly relates to an anti-icing coating easy to remove icing at low temperature and a preparation method thereof.

Background

The existing ice-covering-proof coating technology mostly uses the water contact angle of the coating as a cut-in angle and is made into super-hydrophobic to prevent ice covering. For example, patent CN105001723A, but practical experience shows that simply increasing the water contact angle does not prevent ice covering as expected, and when the air temperature reaches below-5 ℃, the super-hydrophobic coating completely loses the super-hydrophobic non-stick effect on water in liquid state from semi-solid ice-water mixture to full-solid ice, and the ice on the coating is thicker and difficult to remove.

There is a prior art that the coating is modified by fluorinated oligomeric silsesquioxane to improve the hydrophobicity of the coating, and the microstructure of the surface of the patterned coating can promote the generation of cracks and crazes at the interface of the coating and ice, which lead to stress concentration, promote the removal of ice from the surface of the coating, and improve the ice coating prevention performance of the coating. Such as CN1100028899A and CN1042277713A, but the method uses POSS which is inconvenient to operate and expensive, and is not suitable for large-scale commercial production.

CN108587453A discloses a lubricating organic silicon anti-icing coating, which is composed of hydrogen-containing silicone oil, single-end vinyl silicone oil, double-end vinyl silicone oil, silicone oil and a catalyst, wherein the single-end vinyl silicone oil forms a branched chain to provide a storage space for the lubricating silicone oil which does not participate in the reaction, the unreacted silicone oil migrates to the surface to reduce the ice adhesion strength of the coating at low temperature, and the ice shear strength can be as low as 4.5 kPa.

CN109111849A discloses an anti-icing coating, which is prepared by mixing silicon rubber, fluorine-containing monomers, linking agents and catalysts to perform a crosslinking reaction, introducing fluorine-containing side chains into the silicon rubber to prepare fluorine-containing siloxane, and adding liquid paraffin to obtain the anti-icing coating with low ice adhesion strength.

CN104629620A discloses a super-hydrophobic anti-icing coating, which comprises a silane coupling agent, silica sol, a short fluorocarbon chain substituted silane coupling agent and water. The patent also needs to soak the surface of the substrate in alkaline absolute ethyl alcohol with the pH value of 9-11 for 3-7 days when the paint is applied, has complicated operation and long working period, is not easy to operate and is not suitable for treating some surface substrates by the method of the patent.

However, the coating using silicone rubber has a certain effect on preventing ice coating, but simply increasing the water contact angle does not prevent ice coating at low temperature as expected, and when the temperature is below-10 ℃, the super-hydrophobic coating has no effect on super-hydrophobic and non-sticky semi-solid ice-water mixture to fully-solid ice, and the ice on the coating is thicker and more difficult to remove.

Disclosure of Invention

In order to overcome the defect that the icing-resistant coating in the prior art is not easy to remove due to icing at low temperature, the invention mainly solves the problem of icing removal from the angle of interlayer stress difference while paying attention to hydrophobicity. The similar super-hydrophobic anti-icing products on the market are drawn, the teaching that the icing removing capability basically fails under the low-temperature condition is only paid attention to the hydrophobic property and the friction coefficient, and castor oil, double-end vinyl silicone oil and organic silicon modified paraffin which have good flexibility at low temperature and excellent compatibility with fluorosilicone resin are creatively introduced, so that the flexibility of a coating film is greatly improved, and the stress difference between a hard icing layer and a flexible coating layer under the low-temperature environment is very large. Among various silicone oils, through tests, double-end vinyl silicone oil with an obvious good deicing effect is selected and cooperatively matched with organic silicon modified paraffin to provide a lubricating surface in a low-temperature environment; meanwhile, the polytetrafluoroethylene wax is processed to the nanometer level, so that the problem that the PTFE wax sinks due to overlarge specific gravity in the construction film forming process is solved, and meanwhile, the nanometer-level PTFE wax is distributed on the surface of the coating in a hemispherical shape, so that the whole coating has extremely low friction coefficient. The two are cooperated, so that the ice coating can be easily removed at low temperature.

In order to achieve the purpose, the invention adopts the following technical scheme:

the anti-icing coating easy to remove icing at low temperature comprises a component A and a component B, wherein the component A comprises the following raw materials in parts by weight: 60-70 parts of fluorine-silicon composite resin, 0.5-1 part of nano-scale polytetrafluoroethylene, 3-8 parts of castor oil, 6-10 parts of double-end vinyl silicone oil, 6-10 parts of organic silicon modified paraffin and 10-17 parts of first diluent; the component B comprises the following raw materials in parts by weight: 7-10 parts of curing agent and 30-60 parts of second diluent.

The fluorine-silicon composite resin is obtained by polymerizing the following monomers in parts by weight: 50-70 parts of fluorine-containing monomer, 25-32 parts of cyclohexyl vinyl ether, 5-8 parts of hydroxyalkyl vinyl ether, 15-20 parts of polymethyl vinyl siloxane and 2-4 parts of long-chain alkyl olefine acid.

Further, the fluorine-containing monomer includes chlorotrifluoroethylene, fluorine-containing alkyl acrylates (such as pentafluoropropyl acrylate, hexafluorobutyl acrylate, heptafluorobutyl acrylate, octafluoropentyl acrylate, nonafluorohexyl acrylate); the hydroxyalkyl vinyl ether comprises at least one of hydroxybutyl vinyl ether, hydroxypropyl vinyl ether and hydroxy quaternary vinyl ether; the long-chain alkyl acid is at least one of undecylenic diluted acid, dodecyl olefine acid, tetradecenoic acid and hexadecylenic diluted acid.

The conditions for the polymerization reaction for the preparation of the fluorosilicone composite resin are well known in the art, such as initiator and amount, solvent, reaction temperature and reaction time. The initiator is a free radical initiator which is conventional in the field, such as potassium persulfate, ammonium persulfate and benzoyl peroxide, and the amount of the initiator is 2-5% of the mass of the monomer. The polymerization temperature is 40-70 ℃, the proper temperature is selected according to the initiation temperature of the used initiator, and the reaction time is 10-15 h.

The weight average molecular weight of the fluorosilicone composite resin prepared by the method is 35000-60000.

The organic silicon modified paraffin is obtained by a preparation method comprising the following steps: mixing the epoxy-terminated methyl silicone oil and the organic solvent uniformly, adding the solid paraffin, stirring at 70-90 ℃, and evaporating the organic solvent to obtain the organic silicon modified paraffin.

The mass ratio of the epoxy-terminated methyl silicone oil to the solid paraffin is 1-3: 12-16, and all the organic solvents are selected from at least one of ethanol, diethyl ether, tetrahydrofuran and acetone.

The first diluent and the second diluent are at least one of butyl acetate, ethyl acetate, propylene glycol methyl ether acetate, ethylene glycol monomethyl ether, isopropyl acetate, cyclohexanone, methyl n-amyl ketone, methyl ethyl ketone and xylene independently. Preferably, the first diluent is propylene glycol methyl ether acetate, and the second diluent is propylene glycol methyl ether acetate, xylene and butyl acetate in a volume ratio of 5-10: 1-3: 3-5.

The particle size of the nano-scale polytetrafluoroethylene wax is 5-100nm, preferably 10-50nm, and more preferably 15-30 nm; the nano-scale grinding equipment is a nano-sand mill, such as a swiss mill 61130 rod tip sand mill.

The polytetrafluoroethylene wax and part of the first diluent are prepared into 10-20wt% polytetrafluoroethylene wax slurry, and the rest part of the first diluent is added into the preparation component A together with other components. The concentration of the polytetrafluoroethylene wax slurry is prepared to be 10-20%, hemispherical protrusions can be formed on the surface of the coating more favorably, and if the concentration is too high, certain settlement can occur, so that an effective anti-icing effect cannot be achieved; the concentration is too low to effectively form protrusions on the surface of the coating, which is not favorable for the coating to have a low friction coefficient.

The invention processes the polytetrafluoroethylene wax (PTFE) to a nanometer level sphere, prepares a slurry with a certain concentration and adds the slurry into the coating to form countless semi-microspherical protrusions on the surface of the coating. Because PTFE still has good toughness and tensile strength at extremely low temperature, and the high lubricity and non-stick property of PTFE do not obviously deteriorate along with the reduction of temperature. The anti-icing coating which can be easily removed even if covered with ice at a very low temperature of-40 ℃ to-5 ℃ is prepared by adding castor oil and organic silicon modified paraffin.

The curing agent is selected from isocyanate curing agents, such as at least one of HDI, MDI, TDI, IPDI and their dimers and trimers.

Furthermore, the coating also comprises auxiliary materials such as a leveling agent, a defoaming agent, a dispersing agent and the like. The type and amount of adjuvants are well known in the art.

The invention also provides a preparation method of the anti-icing coating easy to remove ice at low temperature, which comprises the following steps:

preparing a component A: adding castor oil, double-end vinyl silicone oil, organic silicon modified paraffin, a first diluent and optionally adding auxiliary materials into the fluorine-silicon composite resin; after uniformly mixing, slowly adding the wax slurry dispersed with the nano PTFE, and uniformly mixing;

preparing a component B: dispersing the curing agent in the second diluent to obtain the product.

When the anti-icing coating prepared by the invention is used, the use amounts of the component A and the component B are prepared according to the use amount of adding 7-10 parts of curing agent to each 100 parts of the component A, the component A and the component B are uniformly mixed and then directly sprayed on a base material needing anti-icing treatment, and the coating easy to remove icing in a low-temperature environment is obtained after drying. The drying temperature range is 15-40 ℃, the anti-icing coating provided by the invention can be cured at normal temperature, if the conditions exist, the anti-icing coating is preferably dried under the heating condition of 35-50 ℃, the curing speed is higher, and the strength of a paint film is higher.

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

the invention overcomes the defect that the icing-proof coating in the prior art is not easy to remove due to icing at low temperature, and mainly solves the problem of icing removal from the angle of interlayer stress difference while paying attention to hydrophobicity.

The inventor unexpectedly finds that the castor oil, the double-end vinyl silicone oil and the organic silicon modified paraffin are introduced after the silicone-fluorine composite resin is prepared, the components are well compatible with each other, and have a synergistic effect, so that the silicone-fluorine composite resin shows particularly excellent low-temperature flexibility, and thus, the stress difference between a hard ice coating layer and a flexible coating layer in a low-temperature environment is very large, and the ice coating can be easily removed under the low-temperature condition.

And thirdly, the polytetrafluoroethylene wax is processed to be in a nanometer level, so that the problem that the PTFE wax sinks due to overlarge specific gravity in the construction process is solved, and meanwhile, the nanometer-level PTFE wax is distributed on the surface of the coating in a hemispherical or microspherical manner, so that the whole coating has an extremely low friction coefficient, and the ice coating prevention effect at low temperature can be helped.

Drawings

FIG. 1 is a water contact angle of the ice-over preventing coating of example 1.

FIG. 2 is an electron micrograph of the anti-icing coating of example 1.

Detailed Description

The epoxy-terminated methyl silicone oil was purchased from Yandi New materials science and technology, Inc., with a kinematic viscosity of 220-²(s) an epoxy value of 0.024mol/100 g. The polytetrafluoroethylene wax was ground by means of a Schlenz 61130 rod tip sand mill to an average particle size of about 20 nm.

Preparation example 1

Putting 58 parts of chlorotrifluoroethylene, 29 parts of cyclohexyl vinyl ether, 5 parts of hydroxybutyl vinyl ether, 15 parts of polymethylvinylsiloxane and 2 parts of dodecenoic acid into 200 parts of solvent butyl acetate, adding 2.5 parts of potassium persulfate, heating to 70 ℃, reacting for 12 hours, cooling and reducing the pressure to normal temperature and pressure to obtain the silicon-fluorine composite resin 1, wherein the weight average molecular weight of the silicon-fluorine composite resin is 47000.

Preparation example 2

The other conditions and procedure were the same as in preparation 1 except that 58 parts of chlorotrifluoroethylene were replaced with 63 parts of hexafluorobutyl acrylate and dodecenoic acid was replaced with hexadecenoic acid of equal mass, to finally obtain a silicofluoride composite resin 2 having a weight average molecular weight of 52000.

Preparation example 3

Uniformly mixing 1 part of epoxy-terminated methyl silicone oil and 6 parts of ethanol, adding 15 parts of solid paraffin, stirring at 70-90 ℃, and evaporating to remove ethanol to obtain the organic silicon modified paraffin 1.

Preparation example 4

And (2) uniformly mixing 3 parts of epoxy-terminated methyl silicone oil and 15 parts of ethanol, adding 15 parts of solid paraffin, stirring at 70-90 ℃, and evaporating to remove ethanol to obtain the organic silicon modified paraffin 2.

Example 1

Preparing a component A: taking 64 parts of the silicon-fluorine composite resin 1 prepared in preparation example 1, adding 5 parts of castor oil, 7 parts of double-end vinyl silicone oil, 8 parts of the organic silicon modified paraffin 1 prepared in preparation example 3, 5 parts of propylene glycol methyl ether acetate, 1 part of deep bamboo 4980 flatting agent and 2 parts of Cortina N3390, uniformly mixing, slowly adding 8 parts of 10 wt% nano PTEE wax slurry with propylene glycol methyl ether acetate as a solvent, and uniformly mixing to obtain a component A;

preparing a component B: evenly dispersing 8 parts of IPDI in 50 parts of propylene glycol methyl ether acetate, xylene and butyl acetate according to a volume ratio of 4: 1: 2 to obtain a component B;

when the coating is used, 8 parts of curing agent is added into each 100 parts of the component A, namely the component A and the component B are uniformly stirred, sprayed on the surface of an aluminum alloy substrate at normal pressure and dried for 24 hours at normal temperature to obtain the coating.

FIG. 2 is an electron micrograph of the anti-icing coating of example 1, and it can be seen that hemispherical protrusions are formed on the surface of the coating.

Example 2

The other conditions and operations were the same as in example 1 except that the silicon fluorine composite resin 1 was replaced with an equal mass of the silicon fluorine composite resin 2 obtained in preparation example 2.

Example 3

The other conditions and operations were the same as in example 1 except that the silicone-modified paraffin 1 was replaced with an equal mass of silicone-modified paraffin 2 obtained in preparation example 4.

Example 4

The other conditions and operation are the same as example 1, except that in the preparation of the component A, the concentration of the nano PTEE wax slurry is 20wt%, the dosage is 4 parts, and the dosage of the propylene glycol monomethyl ether acetate is 9 parts. That is, the total dosage of the diluent propylene glycol monomethyl ether acetate is not changed, one part of the diluent propylene glycol monomethyl ether acetate and the PTEE wax are prepared into wax slurry, and the other part of the diluent propylene glycol monomethyl ether acetate and the PTEE wax are added into the preparation component A together.

Example 5

The other conditions and operation are the same as example 1, except that in the preparation of the component A, the concentration of the nano PTEE wax slurry is 30 wt%, the dosage is 2.67 parts, and the dosage of the propylene glycol monomethyl ether acetate is 10.33 parts. That is, the total dosage of the diluent propylene glycol monomethyl ether acetate is not changed, one part of the diluent propylene glycol monomethyl ether acetate and the PTEE wax are prepared into wax slurry, and the other part of the diluent propylene glycol monomethyl ether acetate and the PTEE wax are added into the preparation component A together.

Example 6

The other conditions and operations are the same as in example 1, except for the formulation of the a component:

preparing a component A: and (2) taking 64 parts of the silicon-fluorine composite resin 1 prepared in the preparation example 1, adding 5 parts of castor oil, 7 parts of vinyl-terminated silicone oil, 8 parts of the organic silicon modified paraffin 1 prepared in the preparation example 3, 1 part of the bambusa 4980 leveling agent and 2 parts of Cortina N3390, uniformly mixing, slowly adding 13 parts of 6.2 wt% nano PTEE wax slurry (the solvent is propylene glycol methyl ether acetate), and uniformly mixing to obtain the component A.

Comparative example 1

The other conditions and operations were the same as in example 1 except that no castor oil was added.

Comparative example 2

The other conditions and operation were the same as in example 1 except that the silicone-modified paraffin wax 1 was replaced with an unmodified paraffin wax.

Comparative example 3

The other conditions and operation were the same as in example 1 except that the PTEE wax was ground to an average particle size of 0.15 μm by means of a vibration mill.

Examples of effects

The coatings obtained in the above examples and comparative examples were subjected to the following tests, and the results are shown in Table 1.

1. Contact angle of water: deionized water was used as the test liquid, and the contact angle of the coating was measured by the pendant drop method using a static water contact angle tester from betho scientific technologies ltd.

2. Ice adhesion strength: the test is carried out by adopting a pull-off method and freezing for more than 12h at two temperatures, namely-15 ℃ and-40 ℃ and the ambient humidity of 85RH percent. The ice adhesion strength after 100 icing/de-icing cycles at-15 ℃ was also tested.

3. Adhesion force: reference is made to the GB1720-79 test. The adhesion force is reduced in 7 grades from 1 grade to 7 grades.

4. Surface friction coefficient: with reference to GB/T22895-2008, MXS-05A friction coefficient tester manufactured by Sanquan Miyashi company was used for testing.

TABLE 1

The data in the table 1 show that the total performance of the anti-icing coating of the embodiment of the invention is excellent, the ice adhesion viscosity is only below 13KPa at the temperature of-15 ℃, the ice adhesion viscosity is slightly improved at the temperature of-40 ℃, but still below 20KPa, the ice adhesion viscosity is not greatly increased after 100 times of icing-deicing cycles, and the anti-icing coating of the invention can be ensured to be used for a long time.

Claims

1. The anti-icing coating easy to remove icing at low temperature comprises a component A and a component B, wherein the component A comprises the following raw materials in parts by weight: 60-70 parts of fluorine-silicon composite resin, 0.5-1 part of nano polytetrafluoroethylene wax, 3-8 parts of castor oil, 6-10 parts of double-end vinyl silicone oil, 6-10 parts of organic silicon modified paraffin and 10-17 parts of first diluent; the component B comprises the following raw materials in parts by weight: 7-10 parts of curing agent and 30-60 parts of second diluent;

the particle size of the nano-scale polytetrafluoroethylene wax is 5-100 nm;

the fluorine-silicon composite resin is obtained by polymerizing the following monomers in parts by weight: 50-70 parts of fluorine-containing monomer, 25-32 parts of cyclohexyl vinyl ether, 5-8 parts of hydroxyalkyl vinyl ether, 15-20 parts of polymethyl vinyl siloxane and 2-4 parts of long-chain alkyl olefine acid;

the fluorine-containing monomer is selected from chlorotrifluoroethylene or fluorine-containing alkyl acrylate; the hydroxyalkyl vinyl ether is at least one of hydroxybutyl vinyl ether and hydroxypropyl vinyl ether; the long-chain alkyl olefine acid is at least one of undecylenic acid, dodecyl olefine acid, tetradecyl olefine acid and hexadecyl olefine acid;

the organic silicon modified paraffin is prepared by a preparation method comprising the following steps: mixing the epoxy-terminated methyl silicone oil and the organic solvent uniformly, adding the solid paraffin, stirring at 70-90 ℃, and evaporating the organic solvent to obtain the organic silicon modified paraffin.

2. The anti-icing coating according to claim 1, wherein the fluorine-containing alkyl acrylate is one selected from the group consisting of pentafluoropropyl acrylate, hexafluorobutyl acrylate, heptafluorobutyl acrylate, octafluoropentyl acrylate, and nonafluorohexyl acrylate.

3. The anti-icing coating according to claim 1, wherein the weight ratio of the epoxy-terminated methyl silicone oil to the paraffin wax is 1-3: 12-16, wherein the organic solvent is at least one of ethanol, diethyl ether, tetrahydrofuran and acetone.

4. The ice-over preventing coating of claim 1, wherein the first and second diluents are independently at least one of butyl acetate, ethyl acetate, propylene glycol methyl ether acetate, ethylene glycol methyl ether, isopropyl acetate, cyclohexanone, methyl n-amyl ketone, methyl ethyl ketone, xylene.

5. The ice coating preventing paint as claimed in claim 4, wherein the first diluent is propylene glycol methyl ether acetate, and the second diluent is propylene glycol methyl ether acetate, xylene and butyl acetate in a volume ratio of 5-10: 1-3: 3-5.

6. The anti-icing coating of claim 1, wherein the nano-scale polytetrafluoroethylene wax has a particle size of 10-50 nm.

7. The anti-icing coating of claim 1, wherein the nano-scale polytetrafluoroethylene wax has a particle size of 15-30 nm.

8. The anti-icing coating according to claim 1, wherein the polytetrafluoroethylene wax and a part of the first diluent are formulated as a 10-20wt% polytetrafluoroethylene wax slurry, and the remaining part of the first diluent is added to the formulation component a together with other components.

9. The method for preparing the anti-icing coating of claim 8, comprising the steps of:

preparing a component A: adding castor oil, double-end vinyl silicone oil, organic silicon modified paraffin, a first diluent and optionally adding auxiliary materials into the fluorine-silicon composite resin; after uniformly mixing, slowly adding the polytetrafluoroethylene wax slurry, and uniformly mixing;

10. The construction method of the anti-icing coating of any one of claims 1 to 8, wherein the amount of the component A and the amount of the component B are adjusted according to the amount of 7 to 10 parts of the curing agent added to each 100 parts of the component A, the component A and the component B are uniformly mixed and then directly sprayed on a substrate needing anti-icing treatment, and the substrate is dried to obtain the coating which is easy to remove ice coating in a low-temperature environment.