A self-lubricating, fouling and self-peeling antifouling coating and a preparation method thereof

Abstract

The present invention relates to the field of coating technology, and in particular to a self-lubricating, defaced and self-stripping antifouling coating and a preparation method thereof. The self-lubricating, defaced and self-stripping antifouling coating comprises a component A and a component B; by weight, the raw material components of the component A comprise: 10 to 35 parts of bisphenol A epoxy resin, 1 to 10 parts of a first silane coupling agent, 5 to 15 parts of a small molecule silicone oil, 1 to 10 parts of potassium silicate, 10 to 20 parts of PTFE micropowder, and 5 to 15 parts of a first solvent; the raw material components of the component B comprise: 50 to 70 parts of an amine curing agent, 5 to 15 parts of a second silane coupling agent, 1 to 5 parts of a chlorinated polyolefin, and 20 to 40 parts of a second solvent. The antifouling coating is a self-lubricating, low-surface-energy antifouling coating, which, in addition to providing low-surface-energy antifouling performance, also has the characteristics of high mechanical strength, good scratch resistance, good compatibility with upper and lower coatings, and easy construction.

Description

Technical Field

[0001] The invention relates to the technical field of coatings, and in particular to a self-lubricating, self-stripping anti-fouling coating and a preparation method thereof. Background Art

[0002] The existing traditional antifouling paint has the following problems:

[0003] (1) Traditional abrasive antifouling paints and self-polishing antifouling paints often contain large amounts of biocides, which can cause damage to the marine ecology.

[0004] (2) Most traditional copper-free antifouling paints also contain organic biocides, which can be toxic to fish and other marine life.

[0005] (3) Existing silicone elastomer coatings: They are elastomeric antifouling paints that use silicone resins (such as hydroxy silicone oil) cured by siloxane crosslinking agents in the presence of metal ion catalysts and combined with low surface energy functional fillers (such as nano-silica, etc.). Although this type of coating is partially non-toxic and can achieve self-release of fouling organisms with a low surface energy paint film, this type of silicone antifouling coating has a small elastic modulus and a soft paint film, which is easily damaged by mechanical abrasion. Furthermore, since the silicone resin system is incompatible with the traditional epoxy-amine primer system, it is easy to cause adhesion failure between the coatings and on-site construction problems.

[0006] In summary, the existing technology has the following problems: the biological toxicity of existing traditional abrasive and self-polishing antifouling paints will cause damage to the marine environment; the existing silicone elastomer coatings have the characteristics of complex construction process, poor compatibility between coatings and poor mechanical properties. Summary of the invention

[0007] In view of the above problems: the biological toxicity of the existing traditional abrasive and self-polishing antifouling paints will cause damage to the marine environment; the existing silicone elastomer coatings have the defects of complex construction process, poor compatibility between coatings and poor mechanical properties. The present invention provides a self-lubricating low surface energy antifouling coating, which, in addition to providing the function of low surface energy antifouling performance, has the characteristics of good compatibility with upper and lower coatings, high mechanical strength and easy construction.

[0008] The self-lubricating, anti-fouling and self-stripping anti-fouling coating comprises a component A and a component B. The raw material components of the component A comprise, by weight, 10 to 35 parts of bisphenol A epoxy resin, 1 to 10 parts of a first silane coupling agent, 5 to 15 parts of small molecule silicone oil, 1 to 10 parts of potassium silicate, 10 to 20 parts of PTFE micropowder and 5 to 15 parts of a first solvent; the raw material components of the component B comprise, 50 to 70 parts of an amine curing agent, 5 to 15 parts of a second silane coupling agent, 1 to 5 parts of a chlorinated polyolefin and 20 to 40 parts of a second solvent.

[0009] In one embodiment, based on parts by weight, the raw material components of the A component include: 10-35 parts of bisphenol A epoxy resin, 1-10 parts of the first silane coupling agent, 0-2 parts of thixotropic agent, 5-15 parts of small molecule silicone oil, 1-10 parts of potassium silicate, 10-20 parts of PTFE micro powder, 5-15 parts of pigment filler, and 5-15 parts of the first solvent.

[0010] In one embodiment, the small molecule silicone oil is one or a combination of two of cyclopentadimethylsiloxane and octamethylcyclotetrasiloxane. Among them, the structural formula of the cyclopentadimethylsiloxane is as follows:

[0011]

[0012] The structural formula of the octamethylcyclotetrasiloxane is as follows:

[0013]

[0014] In one embodiment, the potassium silicate is multi-modulus potassium silicate, and its molecular formula is K2O·nSiO2, where 2 < n < 5 (the molar ratio of SiO2 to K2O is the modulus n, and the definition of multi-modulus means that its modulus is greater than 1. Among the selected potassium silicates, 2 < n < 5, which indicates that its modulus is within this range).

[0015] In one embodiment, the bisphenol A epoxy resin is one or a combination of liquid epoxy resin and semi-solid epoxy resin; the first silane coupling agent is γ-(2,3-epoxypropoxy)propyltrimethoxysilane, and its structural formula is as follows:

[0016]

[0017] In one embodiment, the particle size D50 of the PTFE micro powder is 11-20 μm.

[0018] In one embodiment, the amine curing agent is one or a combination of cardanol phenolic amine, polyamide, and aliphatic amine.

[0019] In one embodiment, the second silane coupling agent is 3-aminopropyltriethoxysilane, and its structural formula is as follows:

[0020]

[0021] In one embodiment, the thixotropic agent is one or a combination of two of fumed silica, hydrogenated castor oil, organic bentonite, and polyamide wax; the pigment filler is one or more combinations of titanium dioxide, red iron oxide, yellow iron oxide, black iron oxide, talcum powder, mica powder, wollastonite powder, feldspar powder, barite powder, and gypsum powder; the first solvent is one or more combinations of xylene, butyl acetate, ethyl acetate, MIBK, cyclohexanone, methyl ethyl ketone, and methyl isobutyl ketone; the second solvent is one or more combinations of xylene, butyl acetate, ethyl acetate, MIBK, cyclohexanone, and methyl ethyl ketone.

[0022] The present invention also provides a method for preparing the self-lubricating, self-stripping antifouling coating as described above, wherein the preparation of component A comprises the following steps:

[0023] Under stirring, add bisphenol A epoxy resin, the first silane coupling agent and small molecule silicone oil into the container, and then add thixotropic agent to disperse into gel; under stirring, add potassium silicate, PTFE powder and pigment filler into the container, disperse evenly to obtain intermediate material; inject the intermediate material and the first solvent into a sand mill for sand milling, and filter to obtain component A;

[0024] The preparation of component B comprises the following steps: adding an amine curing agent, a second silane coupling agent, a chlorinated polyolefin and a second solvent into a container, stirring and dispersing them uniformly, and filtering to obtain component B.

[0025] Compared with the existing technology, the present invention has the following beneficial effects:

[0026] The invention provides a self-lubricating low surface energy antifouling coating, which, in addition to providing low surface energy antifouling performance, also has the characteristics of good scratch resistance, good compatibility with upper and lower coatings, and easy construction. DETAILED DESCRIPTION

[0027] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0028] The present invention provides an operational example of a method for preparing a self-lubricating, fouling and self-stripping antifouling coating, comprising the following steps:

[0029] (1) The preparation of component A comprises the following steps:

[0030] Under medium speed stirring, add bisphenol A epoxy resin, the first silane coupling agent and small molecule silicone oil into the pull cylinder, and then add thixotropic agent to disperse into gel;

[0031] Under high-speed dispersion, potassium silicate, PTFE powder and pigments and fillers are added into the pulling cylinder and dispersed evenly to obtain the intermediate material;

[0032] The intermediate material and the first solvent are injected into a sand mill for sand grinding, and then filtered to obtain component A;

[0033] (2) The preparation of component B comprises the following steps:

[0034] Add an amine curing agent, a second silane coupling agent, a chlorinated polyolefin and a second solvent into the pull cylinder, stir and disperse them evenly, and filter to obtain component B.

[0035] The self-lubricating, self-stripping antifouling coating can be obtained by uniformly mixing component A and component B, and can be used to prepare the coating by spraying or other coating methods. The mass ratio of component A to component B is (6.5-7.0):1.

[0036] The raw material components of component A include: 10-35 parts of bisphenol A epoxy resin, 1-10 parts of the first silane coupling agent, 0-2 parts of thixotropic agent, 5-15 parts of small molecule silicone oil, 1-10 parts of potassium silicate, 10-20 parts of PTFE micropowder, 5-15 parts of pigments and fillers, and 5-15 parts of the first solvent. The raw material components of component B include: 50-70 parts of amine curing agent, 5-15 parts of the second silane coupling agent, 1-5 parts of chlorinated polyolefin, and 20-40 parts of the second solvent.

[0037] The present invention also provides the following embodiments and comparative examples:

[0038] The formulas of the embodiments and comparative examples are shown in Table 1:

[0039] Table 1

[0040]

[0041]

[0042] In Table 1, the types of raw material components selected in the examples are all consistent, specifically:

[0043] The bisphenol A epoxy resin selected is 618 type liquid epoxy resin;

[0044] The first silane coupling agent selected is γ-(2,3-epoxypropoxy)propyltrimethoxysilane

[0045] The thixotropic agent selected is fumed silica;

[0046] The selected small molecule silicone oil is a mixture of cyclopentasiloxane and octamethylcyclotetrasiloxane with a mass ratio of 1:1.

[0047] The molecular formula of the potassium silicate selected is K2O·nSiO2, and its modulus n=2.5;

[0048] The D50 particle size of the selected PTFE micropowder is 12 μm;

[0049] The pigments and fillers used are mica powder, gypsum powder, and pigment red iron oxide; the weight ratio of mica powder to gypsum powder is 2:1, and the weight of red iron oxide is one fifth of that of mica powder;

[0050] The amine curing agent selected is polyamide;

[0051] The second silane coupling agent selected is 3-aminopropyltriethoxysilane;

[0052] The first solvent system and the second solvent system are a combination of xylene, butyl acetate and MIBK in a mass ratio of 1:2:2;

[0053] The preparation process of the lubricating and self-stripping antifouling coating of the embodiment is as follows:

[0054] (1) The preparation of component A comprises the following steps:

[0055] Under medium speed stirring, add bisphenol A epoxy resin, the first silane coupling agent and small molecule silicone oil into the pull cylinder, and then add thixotropic agent, disperse at medium speed for 20 minutes to disperse into gel;

[0056] Under high-speed dispersion, potassium silicate, PTFE powder and pigments and fillers are added into the pulling cylinder, and high-speed dispersion is performed for 30 minutes to obtain the intermediate material;

[0057] The intermediate material and the first solvent are injected into a sand mill for sand grinding for 2 hours, and then filtered to obtain component A;

[0058] (2) The preparation of component B comprises the following steps: adding an amine curing agent, a second silane coupling agent, a chlorinated polyolefin and a second solvent into a pull cylinder, and dispersing them at a stirring speed of 400 rpm for 20 minutes, and filtering to obtain component B.

[0059] The component A and the component B were mixed evenly at a mass ratio of 6.5:1 to obtain a sprayable self-lubricating fouling and self-stripping antifouling coating. The coating was tested, and the test results are shown in Table 2.

[0060] Table 2

[0061] Test items Example 1 Example 2 Example 3 Comparative Example Water contact angle / ° 113 110 107 109 Shallow sea board rating 93 91 88 92 Paint film damage score 6％ 2％ 3％ 91％

[0062] In Table 2, the test methods are:

[0063] The contact angle tester was used to test the water contact angle of the paint surface of Examples 1-3 and the comparative example.

[0064] According to the national standard GB / T 5370-2007 "Shallow Sea Immersion Test Method for Antifouling Paint Samples", Examples 1-3 and the comparative example were tested to obtain shallow sea hanging board scores. The front sea hanging board results were used to evaluate the antifouling performance of the coating. The smaller the score, the worse the antifouling effect.

[0065] According to British standard BS1377: Part 7: Method 5, coal slag is set as the friction medium, and the samples prepared in Examples 1-3 and the comparative example are tested for wear resistance. The input pressure is 100 kPa, and the percentage data of the damaged area of ​​the paint film is obtained;

[0066] In addition, the comparative example uses a conventional fouling-release antifouling coating, specifically a silicone-type antifouling coating that does not contain a biocide.

[0067] Analysis of the above comparative examples and embodiment data shows that:

[0068] (1) The water contact angle test items of the paint surface of Examples 1-3 show that the paint film of the examples has low surface energy characteristics;

[0069] According to the shallow sea board scoring project, the shallow sea board score is greater than 85, indicating that the coating meets the antifouling requirements of medium-term antifouling paint, and the coatings in the embodiments can meet the antifouling requirements of medium-term antifouling paint;

[0070] It can be seen from the friction resistance test items of the embodiment that the elastic modulus of the embodiment is large and the mechanical scratch resistance is good; and because the embodiment coating adopts epoxy resin-amine as the base material, it is compatible with the primer using the traditional epoxy-amine system, and the compatibility between coatings is good. The coating of the embodiment avoids the disadvantages of the traditional fouling release antifouling paint with a small elastic modulus, poor mechanical scratch resistance and incompatibility between coatings.

[0071] (2) The shallow sea board scoring project shows that the coating of the comparative example can meet the antifouling requirements for medium-term antifouling paint; however, the friction resistance test project of the embodiment shows that the friction resistance of the paint film is poor, which affects its application.

[0072] In summary, the self-lubricating, self-stripping antifouling coating provided by the present invention has at least the following design concepts and beneficial effects:

[0073] The present invention adopts an epoxy-amine curing system, so that the paint film reaches a certain mechanical strength after curing, and has good compatibility with the bottom coating; the PTFE particles and slowly released small molecule silicone oil contained in the coating greatly reduce the surface energy of the paint film surface; the multimodular potassium silicate present in the coating slowly releases and hydrolyzes to form a water film on the paint film surface after encountering water, which plays a role in lubricating the paint film, and hydrolyzes to form a local pH value>10, while the suitable pH value for the growth of marine organisms is 8-9, thereby being able to inhibit the growth of marine organisms.

[0074] The present invention introduces multimodular potassium silicate and small molecule silicone oil to make the antifouling coating have self-lubricating function; by introducing PTFE micropowder, the paint film surface has low surface energy fouling self-peeling characteristics. The present invention uses epoxy resin-amine as the base material, which well avoids the disadvantages of traditional fouling release antifouling paint, such as small elastic modulus, mechanical scratch resistance, and incompatibility between coatings;

[0075] It can be seen from the formula of the present invention that the present invention obtains good antifouling performance, good mechanical properties and coating compatibility without containing biocides, and there is no problem of environmental toxicity caused by the release of biocides.

[0076] The self-lubricating, self-stripping, antifouling paint provided by the invention is an environmentally friendly antifouling paint having both the self-stripping, antifouling properties and good mechanical properties and coating compatibility.

[0077] It should be noted that:

[0078] In this article, “~” is used to indicate a numerical range, and the range indicated by this expression includes two endpoint values;

[0079] PTFE is the abbreviation of polytetrafluoroethylene, and MIBK is the abbreviation of methyl isobutyl ketone;

[0080] In addition to the actual selections embodied in the above specific embodiments, the coating formula is as follows by weight: the raw material components of the component A include: 10-35 parts of bisphenol A epoxy resin, 1-10 parts of the first silane coupling agent, 0-2 parts of thixotropic agent, 5-15 parts of small molecule silicone oil, 1-10 parts of potassium silicate, 10-20 parts of PTFE micropowder, 5-15 parts of pigments and fillers, and 5-15 parts of the first solvent. The raw material components of the component B include: 50-70 parts of amine curing agent, 5-15 parts of the second silane coupling agent, 1-5 parts of chlorinated polyolefin, and 20-40 parts of the second solvent. The above formula range is feasible when the present invention is implemented, including but not limited to the above embodiment scheme.

[0081] In addition to the actual selections reflected in the above specific embodiments, preferably, the small molecule silicone oil is selected from one or a combination of two of cyclopentadimethylsiloxane and octamethylcyclotetrasiloxane, including but not limited to the actual selections reflected in the above embodiments;

[0082] In addition to the actual selections reflected in the above specific embodiments, preferably, the potassium silicate is multi-modulus potassium silicate, and its molecular formula is K2O·nSiO2, where 2 < n < 5. During specific implementation, it is feasible to adopt the above parameter range for n, including but not limited to the solutions of the above embodiments.

[0083] In addition to the actual selections reflected in the above specific embodiments, preferably, the bisphenol A epoxy resin is selected from one or a combination of more than one of liquid epoxy resin and semi-solid epoxy resin, including but not limited to the solutions of the above embodiments.

[0084] In addition to the actual selections reflected in the above specific embodiments, preferably, the particle size D50 of the PTFE micro-powder is feasible within the range of 11 to 20 μm, including but not limited to the solutions of the above embodiments.

[0085] In addition to the actual selections reflected in the above specific embodiments, preferably, the thixotropic agent is selected from one or a combination of two of fumed silica, hydrogenated castor oil, organic bentonite, and polyamide wax; the pigment and filler are selected from one or a combination of more than one of titanium dioxide, iron oxide red, iron oxide yellow, iron oxide black, talc powder, mica powder, wollastonite powder, feldspar powder, barite powder, and gypsum powder; the first solvent is selected from one or a combination of more than one of xylene, butyl acetate, ethyl acetate, MIBK, cyclohexanone, methyl ethyl ketone, and methyl isobutyl ketone; the second solvent is selected from one or a combination of more than one of xylene, butyl acetate, ethyl acetate, MIBK, cyclohexanone, and methyl ethyl ketone, including but not limited to the actual selections reflected in the above embodiments.

[0086] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A self-lubricating, self-stripping antifouling coating, characterized in that: It includes component A and component B; The raw material components of the component A include, by weight: 10 to 35 parts of bisphenol A epoxy resin, 1 to 10 parts of a first silane coupling agent, 5 to 15 parts of small molecule silicone oil, 1 to 10 parts of potassium silicate, 10 to 20 parts of PTFE micropowder, and 5 to 15 parts of a first solvent; The raw material components of the second component include: 50-70 parts of an amine curing agent, 5-15 parts of a second silane coupling agent, 1-5 parts of a chlorinated polyolefin, and 20-40 parts of a second solvent; The bisphenol A epoxy resin is one or more combinations of liquid epoxy resin and semi-solid epoxy resin; the first silane coupling agent is γ-(2,3-epoxypropoxy)propyltrimethoxysilane; The small molecule silicone oil is one or a combination of cyclopentasiloxane and octamethylcyclotetrasiloxane; The potassium silicate is a multimodal potassium silicate, and its molecular formula is K2O·nSiO2, wherein 2 <n<5; The particle size D50 of the PTFE micropowder is 11 to 20 μm; The second silane coupling agent is 3-aminopropyltriethoxysilane.

2. The self-lubricating, self-stripping antifouling coating according to claim 1, characterized in that: The raw material components of the component A include, by weight: 10-35 parts of bisphenol A epoxy resin, 1-10 parts of the first silane coupling agent, 0-2 parts of thixotropic agent, 5-15 parts of small molecule silicone oil, 1-10 parts of potassium silicate, 10-20 parts of PTFE micropowder, 5-15 parts of pigments and fillers, and 5-15 parts of the first solvent.

3. The self-lubricating, self-stripping antifouling coating according to claim 1, characterized in that: The amine curing agent is one or more combinations of phenol aldehyde amine, polyamide and fatty amine.

4. The self-lubricating, self-stripping antifouling coating according to claim 2, characterized in that: The thixotropic agent is one or a combination of two of fumed silica, hydrogenated castor oil, organic bentonite, and polyamide wax; The pigment filler is one or more combinations of titanium dioxide, red iron oxide, yellow iron oxide, black iron oxide, talcum powder, mica powder, wollastonite powder, feldspar powder, barite powder, and gypsum powder; The first solvent is one or more of xylene, butyl acetate, ethyl acetate, MIBK, cyclohexanone, methyl ethyl ketone, and methyl isobutyl ketone; The second solvent is one or more of xylene, butyl acetate, ethyl acetate, MIBK, cyclohexanone, and methyl ethyl ketone.

5. A method for preparing the self-lubricating, self-stripping antifouling coating according to claim 2, characterized in that: The preparation of component A comprises the following steps: Under stirring, add bisphenol A epoxy resin, the first silane coupling agent and small molecule silicone oil into the container, and then add thixotropic agent to disperse into gel; Under stirring, add potassium silicate, PTFE powder and pigment filler into the container and disperse them evenly to obtain the intermediate material; The intermediate material and the first solvent are injected into a sand mill for sand grinding, and then filtered to obtain component A; The preparation of component B comprises the following steps: Add an amine curing agent, a second silane coupling agent, a chlorinated polyolefin and a second solvent into a container, stir and disperse them evenly, and filter to obtain component B.

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