Weather-resistant single-component water-based polysiloxane finish paint and preparation method thereof

Abstract

The invention relates to the technical field of coatings, and provides a weather-resistant single-component water-based polysiloxane finish paint and a preparation method thereof.The weather-resistant single-component water-based polysiloxane finish paint is prepared from, by weight, 40-50 parts of water-based acrylic resin, 45-55 parts of polysiloxane, 5-15 parts of pigment, 0.1-0.5 part of dispersing agent, 0.1-0.5 part of cosolvent and 18-24 parts of water; the polysiloxane comprises alkoxy-terminated polysiloxane and unsaturated alkyl-terminated polysiloxane in a mass ratio of (1: 9)-(9: 1). According to the technical scheme, the problems of relatively poor weather resistance and relatively low hardness of single-component water-based finish paint in related technologies are solved.

Description

Technical Field

[0001] The invention relates to the technical field of coatings, and in particular to a weather-resistant single-component water-based polysiloxane topcoat and a preparation method thereof. Background Art

[0002] Water-based topcoats are widely used in the fields of construction, automobiles, furniture, etc. With the development of various industries, the performance requirements for water-based topcoats have become more stringent. Among them, since single-component water-based topcoats can dry and form films by themselves without adding other curing agents and other ingredients during the construction process, they are easy to construct. Therefore, in actual use, single-component water-based topcoats are favored by various industries. However, compared with two-component water-based topcoats, existing single-component water-based topcoats still have problems with poor weather resistance and hardness. For example, the cross-linked structure formed by the paint film of water-based acrylic topcoat after drying is not tight enough and has low hardness. When used outdoors, due to long-term exposure to ultraviolet rays, photochemical reactions are prone to occur, resulting in molecular chain breakage and degradation, and poor weather resistance. This limits the application scope and use effect of single-component water-based topcoats to a certain extent.

[0003] Therefore, it is necessary to obtain a one-component water-based topcoat with excellent weather resistance and high hardness to broaden the application scope of the one-component water-based topcoat and promote the technical development of the one-component water-based topcoat. Summary of the invention

[0004] The invention provides a weather-resistant one-component water-based polysiloxane topcoat and a preparation method thereof, which solves the problems of poor weather resistance and low hardness of the one-component water-based topcoat in the related art.

[0005] The technical solution of the present invention is as follows: The present invention provides a weather-resistant single-component water-based polysiloxane topcoat, comprising the following components in parts by weight: 40-50 parts of water-based acrylic resin, 45-55 parts of polysiloxane, 5-15 parts of pigment, 0.1-0.5 parts of dispersant, 0.1-0.5 parts of cosolvent, and 18-24 parts of water; The polysiloxane includes alkoxy-terminated polysiloxane and unsaturated hydrocarbon-terminated polysiloxane in a mass ratio of 1:9 to 9:1.

[0006] As a further technical solution, the polysiloxane includes alkoxy-terminated polysiloxane and unsaturated hydrocarbon-terminated polysiloxane in a mass ratio of 4 to 7:1.

[0007] In the present invention, alkoxy-terminated polysiloxane and unsaturated hydrocarbon-terminated polysiloxane are used in a mass ratio of 4 to 7:1, thereby further improving the weather resistance and hardness of the single-component water-based topcoat.

[0008] As a further technical solution, the unsaturated hydrocarbon-terminated polysiloxane includes one or both of vinyl-terminated polydimethylsiloxane and allyl-terminated polydimethylsiloxane.

[0009] As a further technical solution, the alkoxy-terminated polysiloxane includes one or both of methyldimethoxy-terminated polydimethylsiloxane and trimethoxy-terminated polydimethylsiloxane.

[0010] As a further technical solution, when the unsaturated hydrocarbon-terminated polysiloxane is vinyl-terminated polydimethylsiloxane, the vinyl content of the vinyl-terminated polydimethylsiloxane is 0.06-0.11 mmol / g.

[0011] In the present invention, when the unsaturated hydrocarbon-terminated polysiloxane is vinyl-terminated polydimethylsiloxane and the vinyl content of the vinyl-terminated polydimethylsiloxane is 0.06-0.11 mmol / g, the weather resistance of the one-component water-based topcoat is further improved.

[0012] As a further technical solution, when the alkoxy-terminated polysiloxane is methyldimethoxy-terminated polydimethylsiloxane and trimethoxy-terminated polydimethylsiloxane, the mass ratio of the methyldimethoxy-terminated polydimethylsiloxane to the trimethoxy-terminated polydimethylsiloxane is 5:1-3.

[0013] In the present invention, when the mass ratio of methyldimethoxy-terminated polydimethylsiloxane to trimethoxy-terminated polydimethylsiloxane is 5:1-3, the weather resistance of the one-component water-based topcoat is further improved.

[0014] As a further technical solution, the water-based acrylic resin is a water-based alkyd-modified acrylic resin.

[0015] As a further technical solution, the pigment includes one or more of titanium dioxide, calcium carbonate, and carbon black; the model of the dispersant includes one or more of BYK-110, BYK-190, BYK-163, and BYK-9076; and the co-solvent is an alcohol ether solvent.

[0016] The present invention also provides a method for preparing the weather-resistant one-component water-based polysiloxane topcoat, comprising the following steps: The components of the weather-resistant one-component water-based polysiloxane topcoat are mixed to obtain the weather-resistant one-component water-based polysiloxane topcoat.

[0017] As a further technical solution, the mixing speed is 600-800 r / min and the mixing time is 40-50 min.

[0018] The present invention also proposes the use of the weather-resistant one-component water-based polysiloxane topcoat or the weather-resistant one-component water-based polysiloxane topcoat prepared by the preparation method in metal decorative topcoats, such as surface protection or decoration of C-shaped steel, H-shaped steel, mechanical equipment, pipe racks, environmental protection equipment, pipe fittings, grid structures, steel pipes, and color steel renovation.

[0019] The working principle and beneficial effects of the present invention are: In the present invention, water-based acrylic resin, polysiloxane, pigment and the like are used as components of a single-component water-based polysiloxane topcoat, wherein the polysiloxane is compounded and coordinated with an alkoxy-terminated polysiloxane and an unsaturated hydrocarbon-terminated polysiloxane in a mass ratio of 1:9 to 9:1, thereby significantly improving the weather resistance and hardness of the single-component water-based topcoat. Meanwhile, the prepared single-component water-based polysiloxane topcoat is non-toxic, odorless and pollution-free, and compared with a two-component topcoat, has the advantages of higher hardness, convenient construction and low material cost. DETAILED DESCRIPTION

[0020] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only 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.

[0021] In the following examples and comparative examples, the model of the waterborne alkyd-modified acrylic resin is S-926, which was purchased from Jining Tangyi Chemical Co., Ltd.

[0022] The polysiloxanes terminated with different functional groups are all functional group double-terminated polysiloxanes: the viscosity of methyldimethoxy-terminated polydimethylsiloxane is 35000mPa·s; the viscosity of trimethoxy-terminated polydimethylsiloxane is 20000mPa·s; the viscosity of vinyl-terminated polydimethylsiloxane with a vinyl content of 0.05mmol / g is 10000mPa·s; the viscosity of vinyl-terminated polydimethylsiloxane with a vinyl content of 0.15mmol / g is 500mPa·s; the viscosity of vinyl-terminated polydimethylsiloxane with a vinyl content of 0.06mmol / g is 5000mPa·s; the viscosity of vinyl-terminated polydimethylsiloxane with a vinyl content of 0.11mmol / g is 1000mPa·s; all of them were purchased from Jiangsu Keqi Polymer Materials Research Institute Co., Ltd. Allyl-terminated polydimethylsiloxane was purchased from Shanghai Jilaid New Materials Technology Co., Ltd.

[0023] Example 1 A weather-resistant one-component water-based polysiloxane topcoat, comprising the following components in parts by weight: 40 parts of water-based alkyd-modified acrylic resin, 45 parts of polysiloxane, 5 parts of titanium dioxide, 0.1 parts of dispersant BYK-190, 0.1 parts of propylene glycol butyl ether, and 18 parts of water; The polysiloxane is methyldimethoxy-terminated polydimethylsiloxane and vinyl-terminated polydimethylsiloxane in a mass ratio of 1:9; the vinyl content of the vinyl-terminated polydimethylsiloxane is 0.05 mmol / g; The preparation method of the weather-resistant one-component water-based polysiloxane topcoat comprises the following steps: The components of the weather-resistant one-component waterborne polysiloxane topcoat were mixed at a rotation speed of 600 r / min for 50 minutes to obtain the weather-resistant one-component waterborne polysiloxane topcoat.

[0024] Example 2 A weather-resistant one-component water-based polysiloxane topcoat, comprising the following components in parts by weight: 50 parts of water-based alkyd-modified acrylic resin, 55 parts of polysiloxane, 15 parts of carbon black, 0.5 parts of dispersant BYK-110, 0.5 parts of propylene glycol butyl ether, and 24 parts of water; Wherein, the polysiloxane is trimethoxy-terminated polydimethylsiloxane and allyl-terminated polydimethylsiloxane in a mass ratio of 9:1; The preparation method of the weather-resistant one-component water-based polysiloxane topcoat comprises the following steps: The components of the weather-resistant one-component waterborne polysiloxane topcoat were mixed at a rotation speed of 800 r / min for 40 minutes to obtain the weather-resistant one-component waterborne polysiloxane topcoat.

[0025] Example 3 A weather-resistant one-component water-based polysiloxane topcoat, comprising the following components in parts by weight: 45 parts of water-based alkyd-modified acrylic resin, 50 parts of polysiloxane, 5 parts of titanium dioxide, 5 parts of calcium carbonate, 0.2 parts of dispersant BYK-190, 0.1 parts of dispersant BYK-9076, 0.4 parts of propylene glycol butyl ether, and 21 parts of water; The polysiloxane is methyldimethoxy-terminated polydimethylsiloxane and vinyl-terminated polydimethylsiloxane in a mass ratio of 8:1; the vinyl content of the vinyl-terminated polydimethylsiloxane is 0.05 mmol / g; The preparation method of the weather-resistant one-component water-based polysiloxane topcoat comprises the following steps: The components of the weather-resistant one-component water-based polysiloxane topcoat were mixed at a rotation speed of 700 r / min for 45 minutes to obtain the weather-resistant one-component water-based polysiloxane topcoat.

[0026] Example 4 The only difference between this embodiment and embodiment 3 is that the polysiloxane is methyldimethoxy-terminated polydimethylsiloxane and vinyl-terminated polydimethylsiloxane in a mass ratio of 3:1.

[0027] Example 5 The only difference between this embodiment and embodiment 3 is that the polysiloxane is methyldimethoxy-terminated polydimethylsiloxane and vinyl-terminated polydimethylsiloxane in a mass ratio of 7:1.

[0028] Example 6 The only difference between this embodiment and embodiment 3 is that the polysiloxane is methyldimethoxy-terminated polydimethylsiloxane and vinyl-terminated polydimethylsiloxane in a mass ratio of 4:1.

[0029] Example 7 The only difference between this example and Example 6 is that the vinyl content of the vinyl-terminated polydimethylsiloxane is 0.15 mmol / g.

[0030] Example 8 The only difference between this example and Example 6 is that the vinyl content of the vinyl-terminated polydimethylsiloxane is 0.11 mmol / g.

[0031] Example 9 The only difference between this example and Example 6 is that the vinyl content of the vinyl-terminated polydimethylsiloxane is 0.06 mmol / g.

[0032] Example 10 The only difference between this embodiment and embodiment 9 is that methyldimethoxy-terminated polydimethylsiloxane is replaced by trimethoxy-terminated polydimethylsiloxane.

[0033] Embodiment 11 The only difference between this embodiment and embodiment 9 is that one sixth of the methyldimethoxy-terminated polydimethylsiloxane is replaced by trimethoxy-terminated polydimethylsiloxane.

[0034] Example 12 The only difference between this embodiment and embodiment 9 is that three eighths of the methyldimethoxy-terminated polydimethylsiloxane are replaced with trimethoxy-terminated polydimethylsiloxane.

[0035] Comparative Example 1 The only difference between this comparative example and Example 3 is that the polysiloxane is methyldimethoxy-terminated polydimethylsiloxane.

[0036] Comparative Example 2 The only difference between this comparative example and Example 3 is that the polysiloxane is vinyl-terminated polydimethylsiloxane.

[0037] The weather resistance and hardness tests were performed on the weather-resistant one-component water-based polysiloxane topcoats prepared in Examples 1 to 12 and Comparative Examples 1 to 2 respectively: Weathering test: Weathering test was conducted in accordance with the standards GB / T 1865-2009 "Artificial weathering and artificial radiation exposure of paints and varnishes to filtered xenon arc radiation" and GB / T 1766-2008 "Rating method for aging of paints and varnishes", and the surface condition of the single-component waterborne polysiloxane topcoat coating was recorded. Among them, the aging time is 0~1000h: the cracking and shedding of the coating are observed and recorded every 500h; Aging time>1000h: Observe and record the cracking and shedding of the coating every 24h; Hardness test: Test according to standard GB / T 6739-2022 "Determination of film hardness of paints and varnishes by pencil method"; The test results are shown in Table 1 below.

[0038] Table 1 Performance test results of one-component waterborne polysiloxane topcoat

[0039] Compared with Comparative Examples 1 to 2, the one-component water-based polysiloxane topcoats prepared in Examples 1 to 12 have higher hardness and longer weather resistance, indicating that the polysiloxane is compounded and synergistically formulated with alkoxy-terminated polysiloxane and unsaturated hydrocarbon-terminated polysiloxane, which can significantly improve the weather resistance and hardness of the one-component water-based topcoat.

[0040] Compared with Examples 3 to 4, the one-component water-based polysiloxane topcoat prepared in Examples 5 to 6 has higher hardness and longer weather resistance, indicating that the use of alkoxy-terminated polysiloxane and unsaturated hydrocarbon-terminated polysiloxane in a mass ratio of 4 to 7:1 can further improve the weather resistance and hardness of the one-component water-based topcoat.

[0041] Compared with Examples 6 to 7, the one-component water-based polysiloxane topcoat prepared in Examples 8 to 9 has higher hardness and longer weather resistance time, indicating that when the unsaturated hydrocarbon-terminated polysiloxane is a vinyl-terminated polydimethylsiloxane and the vinyl content of the vinyl-terminated polydimethylsiloxane is 0.06 to 0.11 mmol / g, the weather resistance of the one-component water-based topcoat can be further improved.

[0042] Compared with Examples 9 to 10, the one-component water-based polysiloxane topcoat prepared in Examples 11 to 12 has higher hardness and longer weather resistance time, indicating that when the alkoxy-terminated polysiloxane is methyldimethoxy-terminated polydimethylsiloxane and trimethoxy-terminated polydimethylsiloxane, and the mass ratio of methyldimethoxy-terminated polydimethylsiloxane to trimethoxy-terminated polydimethylsiloxane is 5:1 to 3, the weather resistance of the one-component water-based topcoat can be further improved.

[0043] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A weather-resistant one-component water-based polysiloxane topcoat, characterized in that: The invention comprises the following components in parts by weight: 40-50 parts of water-based acrylic resin, 45-55 parts of polysiloxane, 5-15 parts of pigment, 0.1-0.5 parts of dispersant, 0.1-0.5 parts of cosolvent, and 18-24 parts of water; The polysiloxane includes alkoxy-terminated polysiloxane and unsaturated hydrocarbon-terminated polysiloxane in a mass ratio of 1:9 to 9:

1.

2. A weather-resistant one-component waterborne polysiloxane topcoat according to claim 1, characterized in that: The polysiloxane includes alkoxy-terminated polysiloxane and unsaturated hydrocarbon-terminated polysiloxane in a mass ratio of 4 to 7:

1.

3. A weather-resistant one-component waterborne polysiloxane topcoat according to claim 1, characterized in that: The unsaturated hydrocarbon-terminated polysiloxane includes one or both of vinyl-terminated polydimethylsiloxane and allyl-terminated polydimethylsiloxane.

4. A weather-resistant one-component waterborne polysiloxane topcoat according to claim 1, characterized in that: The alkoxy-terminated polysiloxane includes one or both of methyldimethoxy-terminated polydimethylsiloxane and trimethoxy-terminated polydimethylsiloxane.

5. A weather-resistant one-component waterborne polysiloxane topcoat according to claim 3, characterized in that: When the unsaturated hydrocarbon-terminated polysiloxane is vinyl-terminated polydimethylsiloxane, the vinyl content of the vinyl-terminated polydimethylsiloxane is 0.06-0.11 mmol / g.

6. A weather-resistant one-component waterborne polysiloxane topcoat according to claim 4, characterized in that: When the alkoxy-terminated polysiloxane is methyldimethoxy-terminated polydimethylsiloxane and trimethoxy-terminated polydimethylsiloxane, the mass ratio of the methyldimethoxy-terminated polydimethylsiloxane to the trimethoxy-terminated polydimethylsiloxane is 5:1-3.

7. A weather-resistant one-component waterborne polysiloxane topcoat according to claim 1, characterized in that: The water-based acrylic resin is a water-based alkyd-modified acrylic resin.

8. A weather-resistant one-component waterborne polysiloxane topcoat according to claim 1, characterized in that: The pigment includes one or more of titanium dioxide, calcium carbonate, and carbon black; the model of the dispersant includes one or more of BYK-110, BYK-190, BYK-163, and BYK-9076; the cosolvent is an alcohol ether solvent; and the diluent is water.

9. The method for preparing a weather-resistant one-component waterborne polysiloxane topcoat according to any one of claims 1 to 8, characterized in that: The following steps are involved: The components of the weather-resistant one-component water-based polysiloxane topcoat are mixed to obtain the weather-resistant one-component water-based polysiloxane topcoat.

10. The method for preparing a weather-resistant one-component waterborne polysiloxane topcoat according to claim 9, characterized in that: The mixing speed is 600-800 r / min and the mixing time is 40-50 min.

Images