A bio-based waterborne road traffic marking paint, and a preparation method and application thereof

Abstract

The application discloses a kind of bio-based water-based road traffic marking paint and its preparation method and application, belong to road traffic coating technical field.The bio-based polyol of the present application is replaced with petroleum-based polyether / polyester polyol to prepare water-based polyurethane emulsion as main film-forming material, which provides toughness and adhesion;Water-based acrylic copolymer emulsion is prepared by core-shell emulsion polymerization process, the shell layer is soft monomer (butyl acrylate, etc.), the core layer is hard monomer (styrene, methyl methacrylate, etc.), and the core-shell structure makes the coating film have flexibility and hardness, and also acts as an auxiliary film-forming material, adjusts the drying speed and hardness;0.5-2.0 parts of thickener dosage, adjust the viscosity, improve the construction performance;Realize the quick drying performance of 2-5 minutes of non-stick embryo time, 10-15 minutes of dry time, greatly shorten the closed traffic time, service life is more than 3 years, and can be directly covered and applied on the surface of old hot melt marking.

Description

Technical Field

[0001] This invention belongs to the field of road traffic coating technology, specifically relating to a bio-based water-based road traffic marking coating, its preparation method, and its application. Background Technology

[0002] Road markings are a crucial infrastructure for ensuring traffic safety. Currently, the widely used hot-melt road marking paints in China (accounting for over 95% in Liaoning Province) use petroleum resin as the main film-forming substance. Application requires heating to 180-220℃, resulting in high energy consumption. Furthermore, they are easily damaged by snowplows and de-icing salt, leading to frequent repairs. While existing water-based road marking paints use water as the dispersion medium and have low VOC content, they still suffer from slow drying speeds (non-sticking time exceeding 30-60 minutes), insufficient adhesion (poor bonding with asphalt pavement and existing hot-melt markings), limited durability (lifespan of only 1-2 years), and limited functionality.

[0003] Therefore, how to develop a water-based traffic marking coating that is environmentally friendly, quick-drying, has high adhesion, excellent durability, and is suitable for the rapid repair of old hot-melt traffic markings has become an important issue that urgently needs to be addressed. Summary of the Invention

[0004] Therefore, the purpose of this invention is to provide a bio-based water-based road traffic marking paint, its preparation method and application, to solve the technical problems of existing water-based traffic marking paints, such as slow drying speed, insufficient adhesion, poor water resistance, limited durability, and difficulty in using them for the repair of old hot-melt traffic markings.

[0005] To achieve the above objectives, the present invention provides the following technical solution: In a first aspect, the present invention provides a bio-based water-based road traffic marking paint, comprising the following components in parts by weight: 30-50 parts of bio-based waterborne polyurethane emulsion, 10-25 parts of waterborne acrylic copolymer emulsion, 3-10 parts of nano-silica, 5-15 parts of nano-titanium dioxide, 10-20 parts of titanium dioxide, 5-15 parts of heavy calcium carbonate, 0.5-2.0 parts of bio-based dispersant, 0.2-1.0 parts of bio-based defoamer, 1.0-3.0 parts of film-forming aid, 0.5-2.0 parts of thickener, and 10-30 parts of deionized water.

[0006] The functional descriptions of each component are shown in Table 1.

[0007] Table 1: Functional Description.

[0008]

[0009] For the wetting and dispersion of pigments and fillers, a bio-based dispersant is selected: Lubrizol's Solsperse™ 29000. This is a 100% active polymer dispersant, primarily composed of high-molecular-weight polymers, with 50-55% carbon content derived from sustainable raw materials such as plant-based sources. Samples can be obtained by contacting a Lubrizol account manager or visiting their website. Another option is ChemiTech's KMK-360, a bio-based dispersant containing anchoring groups, which can be purchased from Guangzhou ChemiTech New Materials Co., Ltd.

[0010] Among them, the bio-based defoamer is used to eliminate bubbles and improve coating quality; Elementis' DAPRO® BIO 9910 is selected. DAPRO® BIO 9910 is a mixture of vegetable oil / wax components with a small amount of special organosilicon. This product is a 100% effective water-based defoamer with a bio-based carbon content of up to 96%, made from renewable vegetable oils, exhibiting good compatibility and rapid defoaming. It can be obtained through Elementis China's official website or its authorized distributors (such as DKSH).

[0011] The film-forming aid, used to promote film formation in emulsions, is Eastman's TEXANOL OE-300, chemically named 2,2,4-trimethyl-1,3-pentanediol monoisobutyrate, a diester compound. This product is a low-odor, non-VOC "green" film-forming aid with a purity ≥98%, a diester structure, and exhibits synergistic effects with associative thickeners. It can be purchased through its authorized distributors (such as Guangzhou Xinri Chemical Technology Co., Ltd. and Guangzhou Yachuang New Materials Co., Ltd.).

[0012] The thickener, RHEOLATE® 255 from Elementis, is used to adjust the viscosity of the coating. This polyurethane associative thickener, specifically composed of polyether urea polyurethane or polyether polyurethane, effectively provides medium shear viscosity (KU) and improves flowability and leveling. It can be purchased through its distributors (such as Shanghai Kaiyin Chemical).

[0013] Based on the above technical solution, further, the fineness of the nano-silica, the nano-titanium dioxide, the titanium dioxide and the heavy calcium carbonate are all ≤30μm.

[0014] Based on the above technical solution, the solid content of the bio-based waterborne polyurethane emulsion is further 35%-45%.

[0015] Based on the above technical solution, the aqueous acrylic copolymer emulsion is a core-shell structured acrylic copolymer emulsion, wherein the shell layer of the core-shell structure is copolymerized from butyl acrylate and ethyl acrylate, and the core layer of the core-shell structure is copolymerized from methyl methacrylate and styrene.

[0016] Secondly, the present invention provides a method for preparing the above-mentioned bio-based water-based road traffic marking paint, comprising the following steps: Nano-silica, nano-titanium dioxide, titanium dioxide, and heavy calcium carbonate are added to deionized water and a bio-based dispersant under stirring. After dispersion, the mixture is ground to a fineness ≤30μm. Bio-based waterborne polyurethane emulsion and waterborne acrylic copolymer emulsion are added for compounding. Then, bio-based defoamer, film-forming aid, and thickener are added sequentially and stirred evenly. After filtration, the bio-based waterborne road traffic marking paint is obtained.

[0017] Based on the above technical solution, the dispersion time is further set at 45 minutes, and the grinding is carried out using a sand mill.

[0018] Based on the above technical solution, the preparation method of the bio-based aqueous polyurethane emulsion is as follows: Bio-based polyol was dehydrated under vacuum at 110°C for 1.5 h, cooled to 75°C, and then isophorone diisocyanate and dimethylolpropionic acid were added. The reaction was carried out under nitrogen protection for 3 h to obtain a prepolymer. The prepolymer was cooled to 45°C, and triethylamine was added to neutralize and form a salt. Deionized water was added under stirring for emulsification and dispersion. Ethylenediamine was added for chain extension reaction to obtain a bio-based waterborne polyurethane emulsion. The weight ratio of the bio-based polyol, the isophorone diisocyanate, the dimethylolpropionic acid, the triethylamine, the deionized water, and the ethylenediamine is 40:28:4.5:3.5:50:2.

[0019] The bio-based polyol is castor oil-based polyol or lignin-based polyol.

[0020] Based on the above technical solution, the preparation method of the aqueous acrylic copolymer emulsion is as follows: Preparation of continuous phase: Deionized water and emulsifier are mixed and heated to 80°C to obtain a continuous phase; Shell preparation: Butyl acrylate, ethyl acrylate and ammonium persulfate are pre-emulsified and then added dropwise to the continuous phase, kept at the temperature for 1.5 h, and polymerized to form a soft shell; Core layer preparation: Styrene, methyl methacrylate and ammonium persulfate were pre-emulsified and then added dropwise to the continuous phase, and the mixture was kept at the temperature for 2.5 h to polymerize and form a hard core layer; The temperature was lowered to below 40°C, the pH was adjusted to 8.0, and the mixture was filtered to obtain the aqueous acrylic copolymer emulsion. In the preparation of the shell, the weight ratio of butyl acrylate, ethyl acrylate, ammonium persulfate, deionized water, and emulsifier in the continuous phase is 15:10:0.5:50:2. In the preparation of the core layer, the weight ratio of styrene, methyl methacrylate, ammonium persulfate, deionized water, and emulsifier in the continuous phase is 15:10:0.5:50:2.

[0021] Thirdly, the present invention provides the application of the above-mentioned bio-based water-based road traffic marking paint in the repair of old hot-melt traffic markings.

[0022] Compared with the prior art, the present invention has the following beneficial effects: 1. The bio-based waterborne road traffic marking paint provided by this invention uses a waterborne polyurethane emulsion prepared by replacing petroleum-based polyether / polyester polyol with a bio-based polyol as the main film-forming substance, which provides toughness and adhesion; the waterborne acrylic copolymer emulsion is prepared by a core-shell emulsion polymerization process, with a soft monomer (butyl acrylate, etc.) in the shell layer and a hard monomer (styrene, methyl methacrylate, etc.) in the core layer. The core-shell structure gives the coating both flexibility and hardness, and at the same time, it acts as an auxiliary film-forming substance to adjust the drying speed and hardness; the amount of thickener is 0.5-2.0 parts to adjust the viscosity and improve the construction performance; it achieves rapid drying performance with a non-stick time of 2-5 minutes and a drying time of 10-15 minutes, which greatly shortens the time of traffic closure, has a service life of more than 3 years, and can be directly applied to the surface of old hot melt markings.

[0023] 2. This invention uses water as the dispersion medium, with a bio-based content ≥30% and VOC ≤50g / L. It has no irritating odor when applied at room temperature. Through the chemical bonding of bio-based polyurethane polar groups to the substrate surface and the microscopic mechanical locking of nanofillers, its adhesion strength to asphalt pavement and old hot-melt markings is significantly better than existing water-based coatings. Nano-titanium dioxide photocatalytically decomposes organic pollutants on the surface. It can be directly applied to the surface of old hot-melt markings, with a repair layer thickness of 0.6mm, a repair speed increased by about 10 times, and a repair cost reduced by about 25%. It has a service life of more than 3 years, and compared with hot-melt marking paint, the cost is reduced by about 35% and the service life is extended by about 4 times.

[0024] 3. This invention adopts the core technical route of "bio-based emulsion + nanofiller modification"; synergistic film-forming formulation of bio-based waterborne polyurethane and core-shell structured acrylic copolymer; combined enhancement and functional modification of nano-silica and nano-titanium dioxide; realization of rapid drying performance; and interface bonding technology suitable for repairing old hot-melt markings. Attached Figure Description

[0025] To more clearly illustrate the embodiments of the present invention, the accompanying drawings involved in the embodiments will be briefly described below.

[0026] Figure 1 This is an overall flow chart of the preparation process of the present invention; Figure 2 This is a schematic diagram of the cross-sectional structure of the coating in Embodiment 1 of the present invention. Detailed Implementation

[0027] The present invention will be described in detail below with reference to the embodiments. However, the implementation of the present invention is not limited thereto. Obviously, the embodiments described below are only some embodiments of the present invention. For those skilled in the art, other similar embodiments can be obtained without creative effort and all fall within the protection scope of the present invention.

[0028] All parts mentioned in the following examples are by weight.

[0029] Example 1 This embodiment describes the preparation of a bio-based water-based road traffic marking paint.

[0030] like Figure 1 As shown, the process flow diagram illustrates the complete process from raw material preparation, preparation of bio-based waterborne polyurethane emulsion, preparation of core-shell structured acrylic copolymer emulsion, dispersion and grinding of pigments and fillers, mixing and blending of various components to finished product filtration and packaging.

[0031] The preparation of the bio-based waterborne polyurethane emulsion was as follows: 40 parts of castor oil-based polyol were added to a reaction vessel and dehydrated under vacuum at 110°C for 1.5 hours; the temperature was lowered to 75°C, and 28 parts of isophorone diisocyanate and 4.5 parts of dimethylolpropionic acid were added, and the reaction was carried out under nitrogen protection for 3 hours; the temperature was lowered to 45°C, and 3.5 parts of triethylamine were added for neutralization; 50 parts of deionized water were added under high-speed stirring for emulsification; 2 parts of ethylenediamine were added for chain extension to obtain a bio-based waterborne polyurethane emulsion with a solid content of 42%.

[0032] The preparation of core-shell structured acrylic copolymer emulsion: Heat 50 parts deionized water and 2 parts emulsifier to 80°C. The shell monomers (15 parts butyl acrylate, 10 parts ethyl acrylate, and 0.5 parts ammonium persulfate) were pre-emulsified and added dropwise, and kept warm for 1.5 hours. The core layer monomers (15 parts styrene, 10 parts methyl methacrylate, and 0.5 parts ammonium persulfate) were pre-emulsified and added dropwise, and kept at the temperature for 2.5 hours. Cool down and adjust the pH to 8.0, then filter and discharge.

[0033] The coating formulation is as follows: 20 parts deionized water + 1.0 part bio-based dispersant, 15 parts titanium dioxide, 10 parts heavy calcium carbonate, 6 parts nano silica, and 10 parts nano titanium dioxide are added sequentially under stirring, dispersed at high speed for 45 minutes, and sand-milled to a fineness ≤30μm; 40 parts bio-based waterborne polyurethane emulsion and 18 parts acrylic copolymer emulsion are added and stirred evenly; 2.0 parts film-forming aid, 0.5 parts defoamer, and 1.0 part thickener are added sequentially to adjust the viscosity to 100KU, and the material is filtered out to obtain bio-based waterborne road traffic marking paint.

[0034] Nano-silica is fumed nano-silica with an average particle size of 10-50 nm; nano-titanium dioxide is rutile with an average particle size of 10-30 nm.

[0035] The resulting bio-based water-based road marking paint, such as Figure 2 As shown, the interpenetrating network structure of the bio-based waterborne polyurethane and acrylic copolymer, the uniform dispersion of nano-silica and nano-titanium dioxide in the coating film, and the adhesion state of the coating film to the substrate interface are demonstrated.

[0036] Test results show that the product has a non-stick time of 3 minutes, a drying time of 12 minutes, a pull-out adhesion of 2.8 MPa, an abrasion resistance (200 rpm / 1000g) of 25 mg, and a VOC content of 45 g / L. All of these indicators are better than the requirements of the JT / T 280 standard.

[0037] Example 2 The difference between this embodiment and embodiment 1 is that: 50 parts of bio-based waterborne polyurethane emulsion, 12 parts of acrylic copolymer emulsion, 4 parts of nano silica, 8 parts of nano titanium dioxide, 18 parts of titanium dioxide, and 8 parts of heavy calcium carbonate.

[0038] Test results show: non-stick time 4 min, drying time 15 min, adhesion 2.5 MPa, and VOC content 42 g / L.

[0039] Example 3 The difference between this embodiment and embodiment 1 is that: Replace castor oil-based polyols with lignin-based polyols; The coating formulation uses 30 parts of bio-based waterborne polyurethane emulsion, 10 parts of waterborne acrylic copolymer emulsion, 3 parts of nano-silica, 5 parts of nano-titanium dioxide, 10 parts of titanium dioxide, 5 parts of heavy calcium carbonate, 0.5 parts of bio-based dispersant, 0.2 parts of bio-based defoamer, 1.0 part of film-forming aid, 0.5 parts of thickener, and 10 parts of deionized water.

[0040] Test results show: non-stick time 5 min, drying time 18 min, adhesion 2.1 MPa, abrasion resistance (200 rpm / 1000g) 35 mg, and VOC content 48 g / L.

[0041] Example 4 The difference between this embodiment and embodiment 3 is that: The coating formulation uses 50 parts of bio-based waterborne polyurethane emulsion, 25 parts of waterborne acrylic copolymer emulsion, 10 parts of nano-silica, 15 parts of nano-titanium dioxide, 20 parts of titanium dioxide, 15 parts of heavy calcium carbonate, 2.0 parts of bio-based dispersant, 1.0 part of bio-based defoamer, 3.0 parts of film-forming aid, 2.0 parts of thickener, and 30 parts of deionized water.

[0042] Test results show: non-stick time 2 min, drying time 10 min, adhesion 3.2 MPa, abrasion resistance (200 rpm / 1000g) 20 mg, and VOC content 40 g / L.

[0043] Example 5 The bio-based water-based road traffic marking paint prepared in Example 1 was directly sprayed onto the surface of old hot-melt traffic markings (only dust needed to be removed, no need to remove the old markings), with a thickness of 0.6 mm, applied at room temperature. The non-stick time was 3 minutes, and the drying time was 12 minutes. After repair, the marking surface was smooth, with good adhesion, and a service life of over 3 years.

[0044] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A bio-based water-based road marking paint, characterized in that, It consists of the following components in parts by weight: 30-50 parts of bio-based waterborne polyurethane emulsion, 10-25 parts of waterborne acrylic copolymer emulsion, 3-10 parts of nano-silica, 5-15 parts of nano-titanium dioxide, 10-20 parts of titanium dioxide, 5-15 parts of heavy calcium carbonate, 0.5-2.0 parts of bio-based dispersant, 0.2-1.0 parts of bio-based defoamer, 1.0-3.0 parts of film-forming aid, 0.5-2.0 parts of thickener, and 10-30 parts of deionized water.

2. The bio-based water-based road marking paint according to claim 1, characterized in that, The fineness of the nano-silica, the nano-titanium dioxide, the titanium dioxide, and the heavy calcium carbonate is ≤30μm.

3. The bio-based water-based road marking paint according to claim 1, characterized in that, The solid content of the bio-based waterborne polyurethane emulsion is 35%-45%.

4. The bio-based water-based road marking paint according to claim 1, characterized in that, The aqueous acrylic copolymer emulsion is a core-shell structured acrylic copolymer emulsion, wherein the shell layer of the core-shell structure is copolymerized from butyl acrylate and ethyl acrylate, and the core layer of the core-shell structure is copolymerized from methyl methacrylate and styrene.

5. The method for preparing bio-based waterborne road traffic marking paint according to any one of claims 1 to 4, characterized in that, Includes the following steps: Nano-silica, nano-titanium dioxide, titanium dioxide, and heavy calcium carbonate are added to deionized water and a bio-based dispersant under stirring. After dispersion, the mixture is ground to a fineness ≤30μm. Bio-based waterborne polyurethane emulsion and waterborne acrylic copolymer emulsion are added for compounding. Then, bio-based defoamer, film-forming aid, and thickener are added sequentially and stirred evenly. After filtration, the bio-based waterborne road traffic marking paint is obtained.

6. The preparation method according to claim 5, characterized in that, The dispersion time was 45 minutes, and the grinding was done using a sand mill.

7. The preparation method according to claim 5, characterized in that, The preparation method of the bio-based aqueous polyurethane emulsion is as follows: Bio-based polyol was dehydrated under vacuum at 110°C for 1.5 h, cooled to 75°C, and then isophorone diisocyanate and dimethylolpropionic acid were added. The reaction was carried out under nitrogen protection for 3 h to obtain a prepolymer. The prepolymer was cooled to 45°C, and triethylamine was added to neutralize and form a salt. Deionized water was added under stirring for emulsification and dispersion. Ethylenediamine was added for chain extension reaction to obtain a bio-based waterborne polyurethane emulsion. The weight ratio of the bio-based polyol, the isophorone diisocyanate, the dimethylolpropionic acid, the triethylamine, the deionized water, and the ethylenediamine is 40:28:4.5:3.5:50:

2. The bio-based polyol is castor oil-based polyol or lignin-based polyol.

8. The preparation method according to claim 5, characterized in that, The preparation method of the aqueous acrylic copolymer emulsion is as follows: Preparation of continuous phase: Deionized water and emulsifier are mixed and heated to 80°C to obtain a continuous phase; Shell preparation: Butyl acrylate, ethyl acrylate and ammonium persulfate are pre-emulsified and then added dropwise to the continuous phase, kept at the temperature for 1.5 h, and polymerized to form a soft shell; Core layer preparation: Styrene, methyl methacrylate and ammonium persulfate were pre-emulsified and then added dropwise to the continuous phase, and the mixture was kept at the temperature for 2.5 h to polymerize and form a hard core layer; The temperature was lowered to below 40°C, the pH was adjusted to 8.0, and the material was filtered out to obtain the aqueous acrylic copolymer emulsion. In the preparation of the shell, the weight ratio of butyl acrylate, ethyl acrylate, ammonium persulfate, deionized water, and emulsifier in the continuous phase is 15:10:0.5:50:

2. In the preparation of the core layer, the weight ratio of styrene, methyl methacrylate, ammonium persulfate, deionized water, and emulsifier in the continuous phase is 15:10:0.5:50:

2.

9. The application of the bio-based waterborne road traffic marking paint as described in any one of claims 1 to 4 in the repair of old hot-melt traffic markings.

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