Water-based two-component electrostatic spraying solid color finish paint

Abstract

The invention discloses a water-based two-component electrostatic spraying solid-color finish paint which comprises a component A and a component B, the component A is prepared from the following components in parts by weight: 45 to 55 parts of modified acrylic resin and 6 to 10 parts of propylene glycol monomethyl ether acetate; the component B is prepared from the following components in parts by weight: 18 to 22 parts of water-based aliphatic polyurethane dispersion, 10 to 14 parts of water-based self-extinction polyurethane dispersion, 3 to 5 parts of diethylene glycol monobutyl ether, 0.3 to 0.5 part of wetting agent, 0.2 to 0.4 part of flatting agent, 0.2 to 0.8 part of rheological agent, 5 to 17 parts of pigment and 6 to 8 parts of deionized water. According to the invention, the acrylic resin is firstly modified and then is matched with the waterborne polyurethane system, so that the waterborne two-component electrostatic spraying solid-color finish paint is finally obtained, and the finish paint after film formation is high in hardness, good in wear resistance and relatively high in adhesive force.

Description

Technical Field

[0001] The invention relates to the technical field of coatings, in particular to a water-based two-component electrostatic spraying solid color topcoat. Background Art

[0002] The surfaces of many objects require coatings for protection, decoration and special functions. Among them, water-based wood coatings have been developed for nearly 20 years, and both technology and market have made great progress.

[0003] As an efficient and environmentally friendly coating method, electrostatic spraying technology is widely used in the surface treatment of various substrates. This technology uses the principle of electrostatic adsorption to make the paint particles evenly deposit on the surface of the substrate under the action of the electric field to form a smooth and uniform coating. However, in actual applications, different types of paint will show different characteristics and challenges during the electrostatic spraying process.

[0004] The hydroxyl content of hydroxy polyacrylate in existing water-based wood coatings is relatively high. The paint film obtained by compounding with polyurethane dispersion has high hardness and high corrosion resistance. However, in the prior art, the paint film obtained by compounding hydroxy polyacrylate with polyurethane generally has the problem of poor adhesion. Summary of the invention

[0005] 1. Technical issues to be resolved

[0006] In view of the deficiencies in the prior art, the present invention provides a water-based two-component electrostatic spray solid color topcoat, which solves the problems raised in the above background technology.

[0007] (II) Technical solution

[0008] To achieve the above objectives, the present invention is implemented through the following technical solutions:

[0009] A water-based two-component electrostatic spray solid color topcoat, comprising component A and component B;

[0010] The component A comprises the following components in parts by weight: 35 to 85 parts of isocyanate curing agent and 6 to 10 parts of propylene glycol monomethyl ether acetate;

[0011] The component B comprises the following components in parts by weight: 45 to 55 parts of modified acrylic resin, 18 to 22 parts of water-based aliphatic polyurethane dispersion, 10 to 14 parts of water-based self-matting polyurethane dispersion, 3 to 5 parts of diethylene glycol monobutyl ether, 0.3 to 0.5 parts of wetting agent, 0.2 to 0.4 parts of leveling agent, 0.2 to 0.8 parts of rheological agent, 5 to 17 parts of pigment and 6 to 8 parts of deionized water.

[0012] Further, the preparation method of the modified acrylic resin comprises the following steps:

[0013] S 1 : According to parts by weight, 100 parts of acrylic acid monomer, 6 to 10 parts of hydroxy acrylate and 10 to 14 parts of spiroorthocarbonate acrylate are mixed uniformly to obtain a paste mixture;

[0014] S 2 : According to weight, add 0.6-1 part of sodium dodecylbenzene sulfonate to 14-16 parts of deionized water, mix well, adjust the pH to 8-9 with sodium hydroxide, and then add S 1 The obtained paste-like mixture is stirred to obtain an emulsion;

[0015] S 3 :Take S 2 10-20% of the obtained emulsion is added to the reaction kettle, stirred and heated to 70-85°C, then 1.5-2.5% of the weight of the taken emulsion potassium persulfate is added, stirred evenly, and reacted for 30-50 minutes;

[0016] S 4 : Under continuous heating conditions, add the remaining emulsion to the reactor, add for 20 to 30 minutes, keep warm and react for 3 to 4 hours, and cool and discharge.

[0017] Furthermore, the acrylic monomer includes acrylic acid and / or methacrylic acid.

[0018] Furthermore, the hydroxyacrylate includes one or a mixture of at least two of hydroxyethyl acrylate, hydroxypropyl acrylate, hydroxyethyl methacrylate and hydroxypropyl methacrylate.

[0019] Furthermore, the aqueous aliphatic polyurethane dispersion is a mixture of Joncryl U 4188 and Joncryl U 4190 in a mass ratio of 1:1.

[0020] Furthermore, the aqueous self-matting polyurethane dispersion is Mowipur 1212 dispersion.

[0021] Furthermore, the wetting agent is BYK-3455, the leveling agent is BYK-358, and the rheological agent is BYK-420.

[0022] Furthermore, the pigment is titanium dioxide.

[0023] After adopting the above technical solution, the present invention has the following beneficial effects compared with the prior art:

[0024] 1. The present invention first modifies acrylic resin, and then makes it cooperate with a waterborne polyurethane system composed of a waterborne aliphatic polyurethane dispersion and a waterborne self-matting polyurethane dispersion. The content of the modified acrylic resin and the waterborne polyurethane resin system is kept in a specific ratio range, which is conducive to forming a continuous and dense film layer with high mechanical strength, and finally obtains a waterborne two-component electrostatic spray solid color topcoat. The topcoat after film formation has high hardness, good wear resistance, and high adhesion.

[0025] 2. The modified acrylic resin used in the present invention is polymerized from acrylic monomers, hydroxy acrylates and spirocyclic orthocarbonic acid acrylates, and has a high crosslinking density. Its unique structure enables it to have strong adhesion to the substrate. However, the epoxy structure in the epoxy resin segment will reduce the hardness of the system and affect the wear resistance of the paint film. The present invention uses a specific waterborne polyurethane system to compound the modified acrylic resin. The waterborne polyurethane plays the role of a skeleton and the modified acrylic resin is used for filling. The two cooperate with each other to jointly improve the hardness of the paint film, achieve the shape stability of the paint film, and make the final topcoat have higher hardness and wear resistance. DETAILED DESCRIPTION

[0026] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is by no means intended to limit the present invention and its application or use. 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.

[0027] In the following examples and comparative examples, the wetting agent is BYK-3455 from BYK, the leveling agent is BYK-358 from BYK, the rheological agent is BYK-420 from BYK, the pigment is titanium dioxide, and in Examples 1-3, the aqueous aliphatic polyurethane dispersion is a mixture of Joncryl U 4188 and Joncryl U 4190 in a mass ratio of 1:1, purchased from BASF.

[0028] The water-based self-matting polyurethane dispersion was Mowipur 1212 dispersion, purchased from Archroma Chemicals.

[0029] Spiroorthocarbonate acrylate: 3,9-diethyl-3,9-propyleneoxymethyl-1,5,7,11-tetraoxaspiroundecane (BAOM)

[0030] Example 1

[0031] A water-based two-component electrostatic spray solid color topcoat, comprising component A and component B;

[0032] The component A comprises the following components in parts by weight: 55 parts of a curing agent and 8 parts of propylene glycol monomethyl ether acetate;

[0033] The component B comprises the following components in parts by weight: 50 parts of modified acrylic resin, 20 parts of water-based aliphatic polyurethane dispersion, 12 parts of water-based self-matting polyurethane dispersion, 4 parts of diethylene glycol monobutyl ether, 0.4 parts of wetting agent, 0.3 parts of leveling agent, 0.5 parts of rheological agent, 6 parts of pigment and 7 parts of deionized water.

[0034] The preparation method of the modified acrylic resin comprises the following steps:

[0035] S 1 : According to parts by weight, 100 parts of acrylic acid monomer, 8 parts of hydroxy acrylate and 12 parts of spiroorthocarbonate acrylate are mixed uniformly to obtain a paste mixture;

[0036] S 2 : According to the weight parts, 0.8 parts of sodium dodecylbenzene sulfonate were added to 15 parts of deionized water, mixed evenly, the pH was adjusted to 8 with sodium hydroxide, and then S 1 The obtained paste-like mixture is stirred to obtain an emulsion;

[0037] S 3 :Take S 2 15% of the obtained emulsion was added to the reactor, stirred and heated to 80°C, and then 2.0% of the weight of the emulsion was added with potassium persulfate, stirred evenly, and reacted for 40 minutes;

[0038] S 4 : Under continuous heating conditions, add the remaining emulsion to the reactor, keep the reaction warm for 4 hours after adding for 20 minutes, and cool and discharge.

[0039] The acrylic acid monomer is a 1:1 mixture of acrylic acid and methacrylic acid.

[0040] Hydroxyacrylates include hydroxyethyl acrylate.

[0041] Example 2

[0042] A water-based two-component electrostatic spray solid color topcoat, comprising component A and component B;

[0043] The component A comprises the following components in parts by weight: 55 parts of a curing agent and 6 parts of propylene glycol monomethyl ether acetate;

[0044] The component B comprises the following components in parts by weight: 45 parts of modified acrylic resin, 18 parts of water-based aliphatic polyurethane dispersion, 10 parts of water-based self-matting polyurethane dispersion, 3 parts of diethylene glycol monobutyl ether, 0.3 parts of wetting agent, 0.2 parts of leveling agent, 0.2 parts of rheological agent, 5 parts of pigment, and 6 parts of deionized water.

[0045] The preparation method of the modified acrylic resin comprises the following steps:

[0046] S 1 : According to parts by weight, 100 parts of acrylic acid monomer, 6 parts of hydroxy acrylate and 10 parts of spiroorthocarbonate acrylate are mixed uniformly to obtain a paste mixture;

[0047] S 2 : According to the weight ratio, 0.6 parts of sodium dodecylbenzene sulfonate were added to 14 parts of deionized water, mixed evenly, the pH was adjusted to 8 with sodium hydroxide, and then S 1 The obtained paste-like mixture is stirred to obtain an emulsion;

[0048] S 3 :Take S 2 10% of the obtained emulsion was added to the reactor, stirred and heated to 70°C, and then 1.5% of the weight of the emulsion was added with potassium persulfate, stirred evenly, and reacted for 30 minutes;

[0049] S 4 : Under continuous heating conditions, add the remaining emulsion to the reactor, keep the reaction warm for 3 hours after adding for 20 minutes, and cool and discharge.

[0050] The acrylic monomer is acrylic acid.

[0051] The hydroxy acrylate is hydroxypropyl acrylate.

[0052] Example 3

[0053] A water-based two-component electrostatic spray solid color topcoat, comprising component A and component B;

[0054] The component A comprises the following components in parts by weight: 55 parts of a curing agent and 10 parts of propylene glycol monomethyl ether acetate;

[0055] The component B comprises the following components in parts by weight: 55 parts of modified acrylic resin, 22 parts of water-based aliphatic polyurethane dispersion, 14 parts of water-based self-matting polyurethane dispersion, 5 parts of diethylene glycol monobutyl ether, 0.5 parts of wetting agent, 0.4 parts of leveling agent, 0.8 parts of rheological agent, 13 parts of pigment, and 8 parts of deionized water.

[0056] The preparation method of the modified acrylic resin comprises the following steps:

[0057] S1 : According to parts by weight, 100 parts of acrylic acid monomer, 10 parts of hydroxy acrylate and 14 parts of spiroorthocarbonate acrylate are mixed uniformly to obtain a paste mixture;

[0058] S 2 : According to the weight ratio, add 1 part of sodium dodecylbenzene sulfonate to 16 parts of deionized water, mix well, adjust the pH to 9 with sodium hydroxide, and then add S 1 The obtained paste-like mixture is stirred to obtain an emulsion;

[0059] S 3 :Take S 2 20% of the obtained emulsion was added to the reactor, stirred and heated to 85°C, and then 2.5% of the weight of the emulsion was added with potassium persulfate, stirred evenly, and reacted for 50 minutes;

[0060] S 4 : Under continuous heating conditions, add the remaining emulsion to the reactor, keep the reaction warm for 4 hours after adding for 30 minutes, and cool and discharge.

[0061] Acrylic monomers include methacrylic acid.

[0062] The hydroxy acrylate is hydroxypropyl methacrylate.

[0063] Comparative Example 1: The difference from Example 1 is that in the preparation method of the modified acrylic resin, 12 parts of spirocycloorthocarbonate acrylate are replaced by 12 parts of acrylic acid monomer.

[0064] The preparation method of the modified acrylic resin comprises the following steps:

[0065] S 1 : According to parts by weight, 32 parts of acrylic acid monomer and 8 parts of hydroxy acrylate are mixed uniformly to obtain a paste mixture;

[0066] S 2 : According to the weight parts, 0.8 parts of sodium dodecylbenzene sulfonate were added to 15 parts of deionized water, mixed evenly, the pH was adjusted to 8 with sodium hydroxide, and then S 1 The obtained paste-like mixture is stirred to obtain an emulsion;

[0067] S 3 :Take S 2 15% of the obtained emulsion was added to the reactor, stirred and heated to 80°C, and then 2.0% of the weight of the emulsion was added with potassium persulfate, stirred evenly, and reacted for 40 minutes;

[0068] S 4 : Under continuous heating conditions, add the remaining emulsion to the reactor, keep the reaction warm for 4 hours after adding for 20 minutes, and cool and discharge.

[0069] Comparative Example 2: The difference from Example 1 is that 20 parts of the aqueous aliphatic polyurethane dispersion in component B is replaced by 15 parts of the aqueous aliphatic polyurethane dispersion.

[0070] A water-based two-component electrostatic spray solid color topcoat, comprising component A and component B;

[0071] The component A comprises the following components in parts by weight: 55 parts of a curing agent, 8 parts of propylene glycol monomethyl ether acetate and 18 parts of deionized water;

[0072] The component B comprises the following components in parts by weight: 50 parts of modified acrylic resin, 15 parts of water-based aliphatic polyurethane dispersion, 12 parts of water-based self-matting polyurethane dispersion, 4 parts of diethylene glycol monobutyl ether, 0.4 parts of wetting agent, 0.3 parts of leveling agent, 0.5 parts of rheological agent, 6 parts of pigment, and 7 parts of deionized water.

[0073] Comparative Example 3: The difference from Example 1 is that 20 parts of aqueous aliphatic polyurethane dispersion and 12 parts of aqueous self-matting polyurethane dispersion in component B are replaced by 32 parts of Lamberti aqueous polyurethane dispersion PU98D.

[0074] A water-based two-component electrostatic spray solid color topcoat, comprising component A and component B;

[0075] The component A comprises the following components in parts by weight: 55 parts of a curing agent, 8 parts of propylene glycol monomethyl ether acetate and 18 parts of deionized water;

[0076] The B component includes the following components in parts by weight: 50 parts of modified acrylic resin, 32 parts of Lamberti waterborne polyurethane dispersion PU98D, 4 parts of diethylene glycol monobutyl ether, 0.4 parts of wetting agent, 0.3 parts of leveling agent, 0.5 parts of rheological agent, 6 parts of pigment, and 7 parts of deionized water.

[0077] Comparative Example 4: The difference from Example 1 is that 20 parts of aqueous aliphatic polyurethane dispersion and 12 parts of aqueous self-matting polyurethane dispersion in component B are replaced by 32 parts of Lamberti aqueous polyurethane dispersion PU98D. In addition, in the preparation method of the modified acrylic resin, 12 parts of spirocyclic orthocarbonate acrylate are replaced by 12 parts of acrylic monomer.

[0078] A water-based two-component electrostatic spray solid color topcoat, comprising component A and component B;

[0079] The component A comprises the following components in parts by weight: 55 parts of a curing agent, 8 parts of propylene glycol monomethyl ether acetate and 18 parts of deionized water;

[0080] The B component includes the following components in parts by weight: 50 parts of modified acrylic resin, 32 parts of Lamberti waterborne polyurethane dispersion PU98D, 4 parts of diethylene glycol monobutyl ether, 0.4 parts of wetting agent, 0.3 parts of leveling agent, 0.5 parts of rheological agent, 6 parts of pigment, and 7 parts of deionized water.

[0081] The preparation method of the modified acrylic resin comprises the following steps:

[0082] S 1 : According to parts by weight, 32 parts of acrylic acid monomer and 8 parts of hydroxy acrylate are mixed uniformly to obtain a paste mixture;

[0083] S 2 : According to the weight parts, 0.8 parts of sodium dodecylbenzene sulfonate were added to 15 parts of deionized water, mixed evenly, the pH was adjusted to 8 with sodium hydroxide, and then S 1 The obtained paste-like mixture is stirred to obtain an emulsion;

[0084] S 3 :Take S 2 15% of the obtained emulsion was added to the reactor, stirred and heated to 80°C, and then 2.0% of the weight of the emulsion was added with potassium persulfate, stirred evenly, and reacted for 40 minutes;

[0085] S 4 : Under continuous heating conditions, add the remaining emulsion to the reactor, keep the reaction warm for 4 hours after adding for 20 minutes, and cool and discharge.

[0086] The topcoats obtained in the examples and comparative examples were sprayed onto aluminum plates respectively, with a paint film thickness of 10 μm. After being placed at room temperature for 3 days, the adhesion, pencil hardness and abrasion resistance of the paint films were tested.

[0087] The performance test results of the embodiments and comparative examples are shown in Table 1:

[0088] Table 1

[0089] Adhesion / MPa Pencil hardness Abrasion resistance / times Test Standards GB / T 5210-2006 GB / T 6739-2006 ASTMF2357-04 Example 1 7.5 4H 370 Example 2 7.2 4H 350 Example 3 7.3 4H 335 Comparative Example 1 4.1 3H 240 Comparative Example 2 5.8 2H 210 Comparative Example 3 6.2 2H 150 Comparative Example 4 3.4 H <100

[0090] Comparative Example 1: The difference from Example 1 is that in the preparation method of the modified acrylic resin in component A, 12 parts of spirocycloorthocarbonate acrylate are replaced by 12 parts of acrylic acid monomer.

[0091] Comparison of the paint film prepared in Example 1 with Comparative Example 1 shows that the addition of spirocycloorthocarbonate acrylate can improve the adhesion, hardness and wear resistance of the paint film.

[0092] Comparative Example 2: The difference from Example 1 is that 20 parts of the aqueous aliphatic polyurethane dispersion in component B is replaced by 15 parts of the aqueous aliphatic polyurethane dispersion.

[0093] Comparison of the paint film prepared in Example 1 with Comparative Example 2 shows that the mass ratio between the modified acrylic resin and the waterborne polyurethane resin system can affect the adhesion, hardness and wear resistance of the paint film.

[0094] Comparative Example 3: The difference from Example 1 is that 20 parts of aqueous aliphatic polyurethane dispersion and 12 parts of aqueous self-matting polyurethane dispersion in component B are replaced by 32 parts of Lamberti aqueous polyurethane dispersion PU98D.

[0095] Comparison of the paint film prepared in Example 1 with Comparative Example 3 shows that the use of an aqueous self-matting polyurethane dispersion and an aqueous polyurethane resin system composed of an aqueous self-matting polyurethane dispersion can help improve the adhesion, hardness and wear resistance of the paint film.

[0096] Comparative Example 4: The difference from Example 1 is that 20 parts of aqueous aliphatic polyurethane dispersion and 12 parts of aqueous self-matting polyurethane dispersion in component B are replaced by 32 parts of Lamberti aqueous polyurethane dispersion PU98D. In addition, in the preparation method of the modified acrylic resin in component A, 12 parts of spirocyclic orthocarbonate acrylate are replaced by 12 parts of acrylic monomer.

[0097] The paint film prepared in Example 1 is compared with Comparative Example 4, and combined with Comparative Examples 2 and 3, it can be seen that the modified acrylic resin of the present technical solution and the waterborne polyurethane resin system of the present technical solution have a positive synergistic effect on improving the adhesion, hardness and wear resistance of the paint film.

[0098] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A water-based two-component electrostatic spray solid color topcoat, characterized in that: It includes component A and component B; The component A comprises the following components in parts by weight: 35 to 85 parts of isocyanate curing agent and 6 to 10 parts of propylene glycol monomethyl ether acetate; The component B comprises the following components in parts by weight: 45 to 55 parts of modified acrylic resin, 18 to 22 parts of water-based aliphatic polyurethane dispersion, 10 to 14 parts of water-based self-matting polyurethane dispersion, 3 to 5 parts of diethylene glycol monobutyl ether, 0.3 to 0.5 parts of wetting agent, 0.2 to 0.4 parts of leveling agent, 0.2 to 0.8 parts of rheological agent, 5 to 17 parts of pigment and 6 to 8 parts of deionized water.

2. The water-based two-component electrostatic spray solid color topcoat according to claim 1, characterized in that: The preparation method of the modified acrylic resin comprises the following steps: S1: According to parts by weight, 100 parts of acrylic acid monomer, 6 to 10 parts of hydroxy acrylate and 10 to 14 parts of spiroorthocarbonate acrylate are mixed uniformly to obtain a paste mixture; S2: Add 0.6-1 parts of sodium dodecylbenzene sulfonate to 14-16 parts of deionized water by weight, mix well, adjust the pH to 8-9 with sodium hydroxide, then add to the paste mixture obtained in S1, and stir to obtain an emulsion; S3: Take 10-20% of the emulsion obtained in S2 and add it to the reactor, stir and heat it to 70-85°C, then add 1.5-2.5% of the weight of the emulsion potassium persulfate, stir evenly, and react for 30-50 minutes; S4: Add the remaining emulsion to the reactor dropwise for 20 to 30 minutes, keep the reaction warm for 3 to 4 hours, and cool and discharge.

3. The water-based two-component electrostatic spray solid color topcoat according to claim 2, characterized in that: The acrylic monomer includes acrylic acid and / or methacrylic acid.

4. The water-based two-component electrostatic spray solid color topcoat according to claim 2, characterized in that: The hydroxy acrylate includes one or a mixture of at least two of hydroxyethyl acrylate, hydroxypropyl acrylate, hydroxyethyl methacrylate, and hydroxypropyl methacrylate.

5. The water-based two-component electrostatic spray solid color topcoat according to claim 1, characterized in that: The aqueous aliphatic polyurethane dispersion is a mixture of Joncryl U 4188 and Joncryl U 4190 in a mass ratio of 1:

1.

6. The water-based two-component electrostatic spray solid color topcoat according to claim 1, characterized in that: The aqueous self-matting polyurethane dispersion is Mowipur 1212 dispersion.

7. The water-based two-component electrostatic spray solid color topcoat according to claim 1, characterized in that: The wetting agent is BYK-3455, the leveling agent is BYK-358, and the rheological agent is BYK-420.

8. The water-based two-component electrostatic spray solid color topcoat according to claim 1, characterized in that: The pigment is titanium dioxide.