Single-component moisture-curable graphene conductive coating and preparation method thereof

Abstract

The invention discloses a single-component moisture-curable graphene conductive coating which is prepared from the following components in percentage by weight: 49.0%-59.0% of a polyurethane prepolymer, 10.0%-19.0% of graphene slurry, 0.4%-2.0% of a dispersing agent, 0.1%-0.8% of a defoaming agent, 0.1%-0.3% of a wetting agent and 30.0%-40.0% of an organic solvent 1, wherein the polyurethane prepolymer is prepared from 40.0%-70.0% of polyether polyol, 15.0%-35.0% of aliphatic polyisocyanate, 0.5%-2.0% of a cross-linking agent, 0.1%-0.4% of a catalyst and 14.0%-35.0% of an organic solvent 2, and the graphene slurry is prepared from polyurethane prepolymer resin and graphene according to the weight ratio of 4: 1. The single-component moisture-curable graphene conductive coating not only has good conductivity and excellent mechanical properties, but also has the characteristic of simplicity and convenience in construction.

Description

Technical Field

[0001] The invention belongs to the technical field of conductive coatings, and in particular relates to a single-component moisture-curable graphene conductive coating and a preparation method thereof. Background Art

[0002] Conductive coatings are a type of special functional coating that has developed rapidly along with modern science and technology. They are widely used in aerospace, electronic communications, petrochemicals and other fields. According to the conductivity mechanism, conductive coatings can be divided into two types: blended type and intrinsic type: Intrinsic conductive coatings use conductive polymers as the basic film-forming material, and the conductive properties of the polymer itself make the coating conductive. Blended conductive coatings refer to coatings that do not have conductive properties by adding conductive fillers, thereby making the coating system conductive. Blended conductive coatings can adjust the electrical and mechanical properties of the coating within a large range, and are simple and easy to operate, and can be widely used.

[0003] Polyurethane molecules contain highly polar urethane groups and hydrogen bonds exist between molecules, which makes the paint film prepared with polyurethane as the base resin have good wear resistance, oil resistance, water resistance, toughness, etc. Therefore, polyurethane coatings are widely used in many fields such as construction, transportation, industry, electronics, etc.

[0004] In actual application, the development and application of intrinsic conductive coatings are limited to a certain extent due to the small number of base polymer resins used in intrinsic conductive coatings and the great difficulty in synthesis and construction. Although blended conductive coatings can adjust the electrical and mechanical properties of coatings in a large range and are simple and easy to operate, most blended conductive coatings on the market currently use metal fillers as the main conductive fillers. Metal fillers are either harmful to the environment, easy to oxidize, and unstable in conductivity, which limits their application scope to a certain extent.

[0005] At present, polyurethane coatings are usually cured using a two-component cross-linking system. Although the coating prepared by this method has good protective properties, mechanical properties, adhesion properties and other characteristics, it also has disadvantages such as cumbersome construction process, inconvenient storage, and high requirements on substrate surface conditions, which limits its application in some fields. Summary of the invention

[0006] The main purpose of the present invention is: in view of the problems existing in metal conductive fillers in blended conductive coatings, the present invention uses graphene as a conductive filler to prepare a single-component moisture-curable graphene conductive coating. Graphene has super strong conductivity, excellent mechanical properties, excellent stability and other characteristics, and is an environmentally friendly material that can give the coating excellent conductivity and mechanical properties. In view of the problems existing in two-component polyurethane curing system coatings, the present invention prepares a single-component moisture-curable graphene conductive coating, which has the advantages of simple construction, convenient storage, strong adaptability to substrate surface conditions, etc.

[0007] A single-component moisture-curable graphene conductive coating is provided, which is realized by adopting the following technical scheme: A single-component moisture-curable graphene conductive coating comprises the following raw materials in parts by weight:

[0008]

[0009] The dispersant is one of BYK-163, BYK-110, BYK-190 and BYK-108 or a mixture of several thereof.

[0010] The defoamer is one of BYK-057, BYK-A530, BYK-088 and BYK-065 or a mixture of several thereof.

[0011] The wetting agent is one of BYK-333, BYK-306, BYK-331, BYK-300, BYK-320 or a mixture of several thereof.

[0012] The organic solvent is one or a mixture of 1-butyl acetate, xylene, butanone, acetone, and ethyl acetate.

[0013] The synthetic formula for preparing the polyurethane prepolymer is:

[0014]

[0015] The polyether polyol is one or a mixture of polyoxypropylene glycol, vinyl polymer grafted polyether polyol and polytetramethylene ether glycol, and has a molecular weight of 400-3000.

[0016] The aliphatic polyisocyanate is one or a mixture of IPDI, HDI, 1,4-cyclohexane diisocyanate.

[0017] The cross-linking agent is one or a mixture of trimethylolpropane, glycerol and castor oil.

[0018] The catalyst is one of dibutyltin dilaurate, stannous octoate, and dibutyltin diacetate, or a mixture of several of them.

[0019] The organic solvent 2 is one or a mixture of butyl acetate, xylene, butanone, acetone, and ethyl acetate.

[0020] The present invention also provides a method for preparing a single-component moisture-curable graphene conductive coating, comprising the following steps:

[0021] Step 1, subjecting the measured polyether polyol and cross-linking agent to vacuum dehydration treatment at 100-120° C. to completely remove the water in the system to prevent the water in the system from affecting the reaction;

[0022] Step 2, after the polyether polyol and cross-linking agent subjected to the dehydration treatment in step 1 are cooled to room temperature, a measured amount of aliphatic polyisocyanate, catalyst and organic solvent 2 are added thereto by a one-step feeding method, stirring is started to mix them evenly, the temperature is raised to 60±2° C., and the mixture is reacted for 3 hours under nitrogen protection, and then the temperature is raised to 80±2° C., and the mixture is reacted for 3 hours under nitrogen protection. After the reaction is completed, the mixture is cooled to room temperature to obtain a polyurethane prepolymer;

[0023] Step 3, preparing graphene slurry,

[0024] The polyurethane prepolymer resin prepared in step 2 and graphene are mixed in a weight ratio of 4:1, and ground on a Lansberg grinder for 4 hours to obtain graphene slurry;

[0025] Step 4, preparing a single-component moisture-curable graphene conductive coating:

[0026] The polyurethane prepolymer resin prepared in step 2, the graphene slurry prepared in step 3, the dispersant, the defoamer, the wetting agent and the organic solvent 1 are mixed according to the formula ratio, dispersed and stirred evenly, and the material is filtered to obtain a single-component moisture-curable graphene conductive coating.

[0027] The key technical points of the present invention are: preparation of base resin polyurethane prepolymer, preparation of conductive graphene slurry and compounding of base resin polyurethane prepolymer and conductive graphene slurry. Among them, polyurethane prepolymer can give the coating excellent protective properties, mechanical properties and adhesion properties, and the addition of conductive graphene slurry can make the coating have good conductive properties.

[0028] Beneficial Effects

[0029] The present invention uses graphene as a conductive filler to prepare a single-component moisture-curable graphene conductive coating, which does not require high temperature or special curing conditions for curing and is a coating that can be cured at room temperature. This curing method is simple and easy to implement, and can improve construction efficiency and reduce costs to a certain extent. The addition of the conductive filler graphene makes the coating prepared by the present invention have excellent conductive properties and mechanical properties. DETAILED DESCRIPTION

[0030] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other implementation methods obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0031] Embodiment 1:

[0032] The method for preparing the polyurethane prepolymer is:

[0033] Step 1: 600 g of polyoxypropylene glycol and 12 g of trimethylolpropane were subjected to vacuum dehydration treatment at 110° C. to completely remove the water in the system to prevent the water in the system from affecting the reaction;

[0034] Step 2: After the polyoxypropylene glycol and trimethylolpropane dehydrated in step 1 are cooled to room temperature, 500 g of IPDI, 2.5 g of dibutyltin dilaurate and 350 g of butyl acetate are added thereto by a one-step feeding method, stirring is started to mix them evenly, the temperature is raised to 60±2° C., and the mixture is reacted for 3 h under nitrogen protection, and then the temperature is raised to 80±2° C., and the mixture is reacted for 3 h under nitrogen protection. After the reaction is completed, the mixture is cooled to room temperature to obtain a polyurethane prepolymer;

[0035] Step 3: The preparation method of graphene slurry is:

[0036] The polyurethane prepolymer prepared in step 2 and graphene are mixed in a weight ratio of 4:1, and ground on a Lansberg grinder for 4 hours to obtain graphene slurry;

[0037] Step 4: The preparation method of the single-component moisture-curing graphene conductive coating is as follows:

[0038] 110 g of the polyurethane prepolymer prepared in step 2, 28 g of the graphene slurry prepared in step 3, 1 g of BYK-110, 0.6 g of BYK-088, 0.3 g of BYK-306 and 70 g of xylene were mixed, dispersed and stirred evenly, and the material was filtered to obtain a single-component moisture-curable graphene conductive coating.

[0039] Embodiment 2:

[0040] The method for preparing the polyurethane prepolymer is:

[0041] Step 1: 620 g of polytetramethylene ether glycol and 15 g of trimethylolpropane are subjected to vacuum dehydration treatment at 110° C. to completely remove the water in the system to prevent the water in the system from affecting the reaction;

[0042] Step 2: After the polytetramethylene ether glycol and trimethylolpropane dehydrated in step 1 are cooled to room temperature, 450 g HDI, 3 g stannous octoate and 370 g xylene are added thereto by a one-step feeding method, stirring is started to mix them evenly, the temperature is raised to 60±2° C., and the mixture is reacted for 3 h under nitrogen protection, and then the temperature is raised to 80±2° C., and the mixture is reacted for 3 h under nitrogen protection. After the reaction is completed, the mixture is cooled to room temperature to obtain a polyurethane prepolymer;

[0043] Step 3: The preparation method of graphene slurry is:

[0044] The polyurethane prepolymer and graphene were mixed in a weight ratio of 4:1 and ground on a Lansberg grinder for 4 hours to obtain graphene slurry.

[0045] Step 4: The preparation method of the single-component moisture-curing graphene conductive coating is as follows:

[0046] 115 g of the polyurethane prepolymer prepared in step 2, 30 g of the graphene slurry prepared in step 3, 2 g of BYK-163, 1.2 g of BYK-057, 0.2 g of BYK-333 and 75 g of xylene were mixed, dispersed and stirred evenly, and the material was filtered to obtain a single-component moisture-curable graphene conductive coating.

[0047] After testing, the performance test indicators of the single-component moisture-curable graphene conductive coatings of Example 1 and Example 2, the impact resistance is tested according to GB / T 1732-2020, and the flexibility is tested according to GB / T 1731-2020, etc. are shown in Table 1:

[0048] Table 1 Performance test indicators of single-component moisture-curing graphene conductive coatings

[0049] Test items Example 1 Example 2 Coating appearance Smooth and flat Smooth and flat Impact resistance (positive impact), cm ＞50 ＞50 Flexibility(mm) 1 1 Electrical conductivity (S / cm) 160 172

[0050] It can be seen from the above table that the present invention has achieved good technical effects.

[0051] The present disclosure has been described by the above-mentioned relevant embodiments, but the above-mentioned embodiments are only examples for implementing the present disclosure. It must be pointed out that the disclosed embodiments do not limit the scope of the present disclosure. On the contrary, changes and modifications made without departing from the spirit and scope of the present disclosure are all within the scope of patent protection of the present disclosure.

Claims

1. A single-component moisture-curable graphene conductive coating, characterized in that: Calculated by mass percentage, it is composed of the following components: The graphene slurry is prepared from polyurethane prepolymer and graphene in a weight ratio of 4:

1.

2. The one-component moisture-curable graphene conductive coating according to claim 1, characterized in that: The polyurethane prepolymer is composed of the following components by mass percentage:

3. The one-component moisture-curable graphene conductive coating according to claim 1, characterized in that: The dispersant is one of BYK-163, BYK-110, BYK-190 and BYK-108 or a mixture of several thereof.

4. The one-component moisture-curable graphene conductive coating according to claim 1, characterized in that: The defoamer is one of BYK-057, BYK-A530, BYK-088 and BYK-065 or a mixture of several thereof.

5. The one-component moisture-curable graphene conductive coating according to claim 1, characterized in that: The wetting agent is one of BYK-333, BYK-306, BYK-331, BYK-300, BYK-320 or a mixture of several thereof.

6. The one-component moisture-curable graphene conductive coating according to claim 1, characterized in that: The organic solvent 1 is one or a mixture of butyl acetate, xylene, butanone, acetone, and ethyl acetate.

7. The one-component moisture-curable graphene conductive coating according to claim 2, characterized in that: The polyether polyol is one or a mixture of polyoxypropylene glycol, vinyl polymer grafted polyether polyol and polytetramethylene ether glycol, and has a molecular weight of 400-3000.

8. The one-component moisture-curable graphene conductive coating according to claim 2, characterized in that: The aliphatic polyisocyanate is one or a mixture of IPDI, HDI and 1,4-cyclohexane diisocyanate.

9. The one-component moisture-curable graphene conductive coating according to claim 2, characterized in that: The crosslinking agent is one or a mixture of trimethylolpropane, glycerol, and castor oil; the catalyst is one or a mixture of dibutyltin dilaurate, stannous octoate, and dibutyltin diacetate; and the organic solvent 2 is one or a mixture of butyl acetate, xylene, butanone, acetone, and ethyl acetate.

10. A method for preparing the single-component moisture-curable graphene conductive coating according to any one of claims 1 to 9, characterized in that: The following steps are involved: Step 1: subjecting the measured polyether polyol and cross-linking agent to vacuum dehydration treatment at 100-120° C. to completely remove the water in the system; Step 2: After the polyether polyol and cross-linking agent subjected to the dehydration treatment in step 1 are cooled to room temperature, the measured aliphatic polyisocyanate, catalyst and organic solvent 2 are added thereto by a one-step feeding method, stirring is started to mix evenly, the temperature is raised to 60±2° C., and the mixture is reacted for 3 hours under nitrogen protection, and then the temperature is raised to 80±2° C., and the mixture is reacted for 3 hours under nitrogen protection. After the reaction is completed, the mixture is cooled to room temperature to obtain a polyurethane prepolymer; Step 3: The polyurethane prepolymer prepared in step 2 and graphene are mixed in a weight ratio of 4:1, and ground on a Lansbury grinder for 4 hours to obtain graphene slurry; Step 4: Mix the polyurethane prepolymer prepared in step 2, the graphene slurry prepared in step 3, the dispersant, the defoaming agent, the wetting agent and the organic solvent 1 in proportion, disperse and stir them evenly, and filter the material to obtain a single-component moisture-curable graphene conductive coating.

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