Bio-based powder coating composition and coating thereof

Abstract

The invention discloses a bio-based powder coating composition and a coating thereof. The bio-based powder coating composition comprises bio-based thermosetting resin and a curing agent, a bio-based raw material is adopted during synthesis of the bio-based thermosetting resin; according to ASTM D6866-04, radioactive carbon isotope C14 detection is carried out on a bio-based coating obtained after the bio-based powder coating composition is heated and cured, and the C14 content in the bio-based coating is not lower than 34%; the powder coating composition provided by the invention is heated and cured to obtain a bio-based coating, and the content of C14 in the bio-based coating is not less than 34%, so that the bio-based coating meets the requirement of the specific industry or field on recycling of the applied material.

Description

Technical Field

[0001] This invention belongs to the field of powder coatings, specifically relating to a bio-based powder coating composition and its coating. Background Technology

[0002] Thermosetting powder coatings are widely used to replace oil-based and water-based paints for protective and decorative purposes on products in various fields due to their advantages such as being environmentally friendly, energy-efficient, easy to apply, and having little to no VOC emissions. However, with the development of certain industries (especially the furniture industry), there are requirements for the recyclability of the materials used, and existing thermosetting powder coating products (whose bio-based content is usually 0%) cannot meet this specific requirement.

[0003] Therefore, the applicant hopes to conduct research and development to solve the aforementioned technical problems. Summary of the Invention

[0004] In view of this, the purpose of the present invention is to provide a bio-based powder coating composition and its coating. The powder coating composition provided in this application is heated and cured to obtain a bio-based coating. The C14 content in the bio-based coating is not less than 34%, so as to meet the requirements of specific industries or fields for the recyclability of the materials used.

[0005] The technical solution adopted in this invention is as follows: A bio-based powder coating composition includes a bio-based thermosetting resin and a curing agent; wherein the bio-based thermosetting resin is synthesized using bio-based raw materials; the bio-based coating obtained after heating and curing the bio-based powder coating composition is subjected to radiocarbon isotope C14 testing according to ASTM D6866-04, and the C14 content in the bio-based coating is not less than 34%.

[0006] Preferably, the C14 content in the bio-based coating is 34-60%, more preferably 38-50%.

[0007] Preferably, the bio-based thermosetting resin is a polyester resin; and the curing agent is TGIC.

[0008] Preferably, the viscosity of the polyester resin at 200°C is greater than 1000 mPa·s, and more preferably 1200-1500 mPa·s.

[0009] Preferably, the acid value of the polyester resin is not less than 65 mg KOH / g, and more preferably 70-95 mg KOH / g.

[0010] Preferably, the glass transition temperature of the polyester resin is 55-60°C.

[0011] Preferably, the viscosity of the polyester resin at 200°C is 1300-1400 mPa·s, more preferably 1350-1370 mPa·s; and the acid value of the polyester resin is 71-88 mgKOH / g, more preferably 72-75 mgKOH / g.

[0012] Preferably, the bio-based thermosetting resin accounts for 50-85 wt% of the bio-based powder coating composition, and the curing agent accounts for 2-10 wt% of the bio-based powder coating composition.

[0013] Preferably, the bio-based powder coating composition further includes leveling agents and / or degassing agents and / or pigments and / or fillers and / or texturers.

[0014] Preferably, a bio-based coating is obtained by electrostatic spraying and curing the bio-based powder coating composition as described above on a substrate; the bio-based coating is tested for radioactive carbon isotope C14 according to ASTM D6866-04, and the C14 content in the bio-based coating is not less than 34%.

[0015] It should be noted that the acid value testing standard involved in this application is based on GB / T 6743-2008; the viscosity value testing standard is based on GB / T 9751.1-2008; and the glass transition temperature testing standard is based on GB / T19466.2-2004.

[0016] This application introduces a bio-based thermosetting resin as the main resin of the powder coating composition. The bio-based thermosetting resin is synthesized using bio-based raw materials, so that the powder coating composition provided in this application, after heating and curing, yields a bio-based coating. The C14 content in the bio-based coating is not less than 34%, which meets the requirements of specific industries or fields for the recyclability of the materials used. Detailed Implementation

[0017] This application provides a bio-based powder coating composition comprising a bio-based thermosetting resin and a curing agent; wherein the bio-based thermosetting resin is synthesized using bio-based raw materials; the bio-based coating obtained after heating and curing the bio-based powder coating composition is tested for radiocarbon isotope C14 according to ASTM D6866-04, and the C14 content in the bio-based coating is not less than 34%; preferably, in this embodiment, the C14 content in the bio-based coating is 34-60%, more preferably 38-50%.

[0018] Preferably, in this embodiment, the bio-based thermosetting resin is a polyester resin; and the curing agent is TGIC.

[0019] Preferably, in this embodiment, the viscosity of the polyester resin at 200°C is greater than 1000 mPa·s, more preferably 1200-1500 mPa·s; preferably, in this embodiment, the acid value of the polyester resin is not less than 65 mg KOH / g, more preferably 70-95 mg KOH / g; preferably, in this embodiment, the glass transition temperature of the polyester resin is 55-60°C.

[0020] Further preferably, in order to further ensure the mechanical properties of the coating obtained in this embodiment while ensuring the C14 content in the coating, in this embodiment, the viscosity of the polyester resin at 200°C is 1300-1400 mPa·s, more preferably 1350-1370 mPa·s; the acid value of the polyester resin is 71-88 mgKOH / g, more preferably 72-75 mgKOH / g; and the glass transition temperature of the polyester resin is 56-58°C, more preferably 56.6-57.5°C.

[0021] Preferably, in order to further ensure the mechanical properties of the coating obtained in this embodiment while ensuring the C14 content in the coating, in this embodiment, the bio-based thermosetting resin accounts for 50-85 wt% of the bio-based powder coating composition by weight, more preferably 55-75 wt%, and even more preferably 58-70 wt%; the curing agent accounts for 2-10 wt% of the bio-based powder coating composition by weight, more preferably 3-8 wt%.

[0022] In specific implementations of this application, it is also possible to add known leveling agents, degassing agents, antioxidants, dispersants, fillers, pigments, stabilizers, texturers, curing accelerators, functional additives and / or other additives to the powder coating composition. These are all conventional technical choices for those skilled in the art. Specifically, fillers and / or pigments can be, for example, carbon black, aluminum hydroxide, barium sulfate, TiO2, etc.

[0023] In preparing the powder coating composition of this application, any known preparation process can be used. Preferably, in this embodiment, the powder coating composition is obtained by mixing, melt extrusion, and crushing. Of course, other known preparation processes can also be used to obtain the powder coating composition of this embodiment. This application does not have any particular limitation on its preparation process.

[0024] Preferably, this embodiment also proposes a bio-based coating, which is obtained by electrostatic spraying and curing the bio-based powder coating composition as described above on a substrate; the bio-based coating is tested for radioactive carbon isotope C14 according to ASTM D6866-04, and the C14 content in the bio-based coating is not less than 34%; preferably, in this embodiment, the C14 content in the bio-based coating is 34-60%, preferably 38-50%.

[0025] To verify the technical effects of this application, the following sets of embodiments were specifically tested and compared as raw materials for powder coating composition formulations: Example 1: A bio-based powder coating composition, with the formulation ingredients prepared according to Table 1 below:

[0026] The bio-based powder coating composition of Example 1 is obtained by mixing all the above raw materials together, performing one-time melt extrusion and crushing.

[0027] Example 2: The remaining technical solutions of Example 2 are the same as those of Example 1, except that the raw materials for Example 2 are prepared according to the following Table 2:

[0028] Example 3: The remaining technical solutions of Example 3 are the same as those of Example 1, except that the raw materials for Example 3 are prepared according to the following Table 3:

[0029] Example 4: The remaining technical solutions of Example 4 are the same as those of Example 1, except that the raw materials for Example 4 are prepared according to the following Table 4:

[0030] Example 5: The remaining technical solutions of Example 5 are the same as those of Example 1, except that the raw materials for this Example 5 are prepared according to the following Table 5:

[0031] Example 6: The remaining technical solutions of Example 6 are the same as those of Example 1, except that the raw materials for Example 6 are prepared according to the following Table 6:

[0032] Example 7: The remaining technical solutions of Example 7 are the same as those of Example 1, except that the raw materials for Example 7 are prepared according to the following Table 7:

[0033] Example 8: The remaining technical solutions of Example 8 are the same as those of Example 1, except that the raw materials for Example 8 are prepared according to the following Table 8:

[0034] Comparative Example 1: The rest of the technical solutions of Comparative Example 1 are the same as those of Example 1. The difference is that in Comparative Example 1, the polyester resin grade in Example 1 is replaced with polyester resin TM5013 provided by Zhejiang Chuanhua Tiansong. No bio-based raw materials are used in the synthesis. Its acid value range is 75-85 mgKOH / g, and its viscosity at 200°C is 500-2000 mPa.s.

[0035] Comparative Example 2: The rest of the technical solutions of Comparative Example 2 are the same as those of Example 1, except that in Comparative Example 2, the polyester resin brand in Example 1 is replaced with ALLNEX's Crylcoat 2671-3, no bio-based raw materials are used in the synthesis, its acid value ranges from 45 to 51 mgKOH / g, and its viscosity ranges from 4300 to 7300 mPa.s at 200°C.

[0036] According to the implementation schemes proposed in Examples 1-8 and Comparative Examples 1-2 above, the corresponding powder coating compositions were obtained by referring to the preparation process described in Example 1.

[0037] The powder coating compositions prepared in Examples 1-8 and Comparative Examples 1-2 were used respectively. The same aluminum plate was selected as the substrate, and each powder coating composition was cured by baking and heating. The heating temperature was 200°C and the heating time was 10 minutes. Cured coatings (thickness range controlled between 60-90 micrometers) were obtained. The performance of each cured coating was then tested, and the test results are shown in Table 9 below.

[0038]

[0039] It should be noted that the C14 content test involved in this embodiment or comparative example was conducted in accordance with the ASTM D6866-04 standard, and the cross-cut test involved in this embodiment or comparative example was conducted in accordance with the ISO2409-2020 standard.

[0040] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within the present invention.

[0041] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A bio-based powder coating composition, characterized in that, It includes a bio-based thermosetting resin and a curing agent; wherein the bio-based thermosetting resin is synthesized using bio-based raw materials; the bio-based coating obtained after heating and curing the bio-based powder coating composition is tested for radiocarbon isotope C14 according to ASTM D6866-04, and the C14 content in the bio-based coating is not less than 34%.

2. The bio-based powder coating composition according to claim 1, characterized in that, The C14 content in the bio-based coating is 34-60%, preferably 38-50%.

3. The bio-based powder coating composition according to claim 1, characterized in that, The bio-based thermosetting resin is a polyester resin; the curing agent is TGIC.

4. The bio-based powder coating composition according to claim 3, characterized in that, The polyester resin has a viscosity greater than 1000 mPa·s at 200°C, preferably 1200-1500 mPa·s.

5. The bio-based powder coating composition according to claim 3, characterized in that, The acid value of the polyester resin is not less than 65 mg KOH / g, preferably 70-95 mg KOH / g.

6. The bio-based powder coating composition according to claim 3, characterized in that, The glass transition temperature of the polyester resin is 55-60℃.

7. The bio-based powder coating composition according to claim 3, characterized in that, The viscosity of the polyester resin at 200°C is 1300-1400 mPa·s, more preferably 1350-1370 mPa·s; the acid value of the polyester resin is 71-88 mgKOH / g, more preferably 72-75 mgKOH / g.

8. The bio-based powder coating composition according to claim 1, characterized in that, The bio-based thermosetting resin accounts for 50-85 wt% of the bio-based powder coating composition, and the curing agent accounts for 2-10 wt% of the bio-based powder coating composition.

9. The bio-based powder coating composition according to claim 1, characterized in that, The bio-based powder coating composition further includes leveling agents and / or degassing agents and / or pigments and / or fillers and / or texturers.

10. A bio-based coating, characterized in that, The coating is obtained by electrostatic spraying and curing of the bio-based powder coating composition as described in any one of claims 1-9 on a substrate; the bio-based coating is tested for radioactive carbon isotope C14 according to ASTM D6866-04, and the C14 content in the bio-based coating is not less than 34%.

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