Low-temperature curing polyester type powder coating and preparation method thereof

Abstract

The invention discloses a low-temperature curing polyester type powder coating and a preparation method thereof, and belongs to the technical field of epoxy polyester type low-temperature curing powder coatings, the low-temperature curing polyester type powder coating comprises the following raw materials by weight: 46-49 parts of epoxy resin containing an aromatic structure, 3-8 parts of an amine curing agent, 26-30 parts of an inorganic filler, 3-8 parts of a pigment and 3-8 parts of an auxiliary agent; the aromatic polyester resin also has good high-temperature resistance, the aromatic polyester resin is matched with common resin for use, the overall temperature resistance can be improved, a product cured by the amine curing agent has high thermal stability, chemical bonds in a molecular structure are not prone to breakage in a high-temperature environment, and the service life of the product is prolonged. The completeness of the coating can be better maintained, so that the temperature resistance of the epoxy polyester type low-temperature curing powder coating is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of epoxy polyester type low temperature curing powder coatings, and in particular relates to a low temperature curing polyester type powder coating and a preparation method thereof. Background Art

[0002] Epoxy polyester powder coating is a kind of powder coating with epoxy resin and polyester resin as the main film-forming substances. In the low temperature curing system, it can complete the curing reaction at a relatively low temperature by adding special curing agent to form a coating with good performance.

[0003] Although epoxy polyester low temperature curing powder coatings can be cured well in low temperature environments, the coatings formed by them are not as resistant to high temperatures as similar coatings cured at high temperatures. Generally speaking, coatings made of this type of coating may soften, change color, or even lose adhesion at higher temperatures (such as over 180°C). This is because the low temperature curing process makes the cross-linking density of the coating relatively low, and the interaction between the molecular chains is weaker in high temperature environments. Summary of the invention

[0004] The purpose of the present invention is to solve the above-mentioned problems and to propose a low-temperature curing polyester powder coating and a preparation method thereof.

[0005] On the one hand, in order to achieve the above-mentioned purpose, the present invention adopts the following technical scheme: a low-temperature curing polyester powder coating, which includes raw materials in the following weight ratio: 46-49 parts of epoxy resin containing an aromatic structure, 3-8 parts of amine curing agent, 26-30 parts of inorganic filler, 3-8 parts of pigment and 3-8 parts of auxiliary agent.

[0006] As a further description of the above technical solution:

[0007] The invention comprises raw materials in the following weight proportions: 47-48 parts of epoxy resin containing aromatic structure, 5-7 parts of amine curing agent, 27-29 parts of inorganic filler, 5-7 parts of pigment and 5-7 parts of auxiliary agent.

[0008] As a further description of the above technical solution:

[0009] The invention comprises raw materials in the following weight proportions: 47.5 parts of epoxy resin containing aromatic structure, 6 parts of amine curing agent, 28 parts of inorganic filler, 6 parts of pigment and 6 parts of auxiliary agent.

[0010] On the other hand, in order to achieve the above-mentioned object, the present invention adopts the following method: a method for preparing a low-temperature curing polyester powder coating, which comprises the following steps:

[0011] 1) Premixing: Add the raw materials in proportion by weight: 46-49 parts of epoxy resin containing aromatic structure, 3-8 parts of amine curing agent, 26-30 parts of inorganic filler, 3-8 parts of pigment and 3-8 parts of auxiliary agent into a high-speed mixer, premix and evenly disperse them;

[0012] 2) Melt extrusion: Add the premixed materials into the extruder and melt extrude at 100-130°C;

[0013] 3) Cooling and crushing: The extruded material is cooled by cooling rollers or water to solidify it into a solid, and then crushed into small particles by a crusher;

[0014] 4) Fine grinding: The crushed particles are crushed into fine powder through air classification mill or other fine grinding equipment;

[0015] 5) Sieving and grading: The fine powder is graded through a sieve to remove oversized or undersized particles to obtain powder coating that meets the requirements;

[0016] 6) Packaging and storage: Package the prepared powder coating and store it in a dry, cool place.

[0017] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are:

[0018] In the present invention, aromatic polyester resins also have good high temperature resistance. Using them in combination with ordinary resins can improve the overall temperature resistance. The products of amine curing agents after curing have high thermal stability. In high temperature environments, the chemical bonds in their molecular structures are not easy to break, and the integrity of the coating can be better maintained, thereby improving the temperature resistance of epoxy polyester low-temperature curing powder coatings. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 The present invention is a flow chart of a method for preparing a low-temperature curing polyester powder coating. DETAILED DESCRIPTION

[0020] In order to make the purpose, technical solution and advantages of the embodiment of the present invention clearer, the technical solution in the embodiment of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiment of the present invention. Obviously, the described embodiment is a part of the embodiment of the present invention, rather than all the embodiments. The components of the embodiment of the present invention described and shown in the drawings here can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiment of the present invention provided in the drawings is not intended to limit the scope of the claimed invention, but only represents the selected embodiment of the present invention. 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. It should be noted that similar numbers and letters represent similar items in the following drawings, so once an item is defined in one drawing, it does not need to be further defined and explained in the subsequent drawings. In the description of the embodiments of the present invention, it should be noted that the terms "upper", "inside", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship in which the invented product is usually placed when in use, which is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation of the present invention. In the description of the present invention, it should also be noted that, unless otherwise clearly specified and limited, the terms "set", "install", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be directly connected, or indirectly connected through an intermediate medium, or it can be the internal connection of two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0021] Embodiment 1:

[0022] S01: Premixing: Add the raw materials in proportion by weight: 46 parts of epoxy resin with aromatic structure, 3 parts of amine curing agent, 26 parts of inorganic filler, 3 parts of pigment and 3 parts of auxiliary agent into a high-speed mixer and premix them to make them evenly dispersed;

[0023] S02: Melt extrusion: Add the premixed materials into the extruder and melt extrude at 130°C;

[0024] S03: Cooling and crushing: The extruded material is cooled by cooling rollers or water to solidify it into a solid, and then crushed into small particles by a crusher;

[0025] S04: Fine pulverization: The crushed particles are crushed into fine powder through air classification mill or other fine pulverization equipment;

[0026] S05: Sieving and grading: The fine powder is graded through a sieve to remove oversized or undersized particles to obtain powder coating that meets the requirements;

[0027] S06: Packaging and storage: Pack the prepared powder coating and store it in a dry and cool place.

[0028] Embodiment 2:

[0029] S01: Premixing: Add the raw materials in proportion by weight: 49 parts of epoxy resin with aromatic structure, 8 parts of amine curing agent, 30 parts of inorganic filler, 8 parts of pigment and 8 parts of auxiliary agent into a high-speed mixer and premix them to make them evenly dispersed;

[0030] S02: Melt extrusion: Add the premixed materials into the extruder and melt extrude at 100°C;

[0031] S03: Cooling and crushing: The extruded material is cooled by cooling rollers or water to solidify it into a solid, and then crushed into small particles by a crusher;

[0032] S04: Fine pulverization: The crushed particles are crushed into fine powder through air classification mill or other fine pulverization equipment;

[0033] S05: Sieving and grading: The fine powder is graded through a sieve to remove oversized or undersized particles to obtain powder coating that meets the requirements;

[0034] S06: Packaging and storage: Pack the prepared powder coating and store it in a dry and cool place.

[0035] Embodiment 3:

[0036] S01: Premixing: Add the raw materials in proportion by weight: 47 parts of epoxy resin with aromatic structure, 5 parts of amine curing agent, 27 parts of inorganic filler, 5 parts of pigment and 5 parts of auxiliary agent into a high-speed mixer for premixing to make them evenly dispersed;

[0037] S02: Melt extrusion: Add the premixed materials into the extruder and melt extrude at 105°C;

[0038] S03: Cooling and crushing: The extruded material is cooled by cooling rollers or water to solidify it into a solid, and then crushed into small particles by a crusher;

[0039] S04: Fine pulverization: The crushed particles are crushed into fine powder through air classification mill or other fine pulverization equipment;

[0040] S05: Sieving and grading: The fine powder is graded through a sieve to remove oversized or undersized particles to obtain powder coating that meets the requirements;

[0041] S06: Packaging and storage: Pack the prepared powder coating and store it in a dry and cool place.

[0042] Embodiment 4:

[0043] S01: Premixing: Add the raw materials in proportion by weight: 48 parts of epoxy resin with aromatic structure, 7 parts of amine curing agent, 29 parts of inorganic filler, 7 parts of pigment and 7 parts of auxiliary agent into a high-speed mixer for premixing to make them evenly dispersed;

[0044] S02: Melt extrusion: Add the premixed materials into the extruder and melt extrude at 125°C;

[0045] S03: Cooling and crushing: The extruded material is cooled by cooling rollers or water to solidify it into a solid, and then crushed into small particles by a crusher;

[0046] S04: Fine pulverization: The crushed particles are crushed into fine powder through air classification mill or other fine pulverization equipment;

[0047] S05: Sieving and grading: The fine powder is graded through a sieve to remove oversized or undersized particles to obtain powder coating that meets the requirements;

[0048] S06: Packaging and storage: Pack the prepared powder coating and store it in a dry and cool place.

[0049] Embodiment 5:

[0050] S01: Premixing: Add the following raw materials in proportion by weight: 47.5 parts of epoxy resin containing aromatic structure, 6 parts of amine curing agent, 28 parts of inorganic filler, 6 parts of pigment and 6 parts of auxiliary agent into a high-speed mixer for premixing to make them evenly dispersed;

[0051] S02: Melt extrusion: Add the premixed materials into the extruder and melt extrude at 118°C;

[0052] S03: Cooling and crushing: The extruded material is cooled by cooling rollers or water to solidify it into a solid, and then crushed into small particles by a crusher;

[0053] S04: Fine pulverization: The crushed particles are crushed into fine powder through air classification mill or other fine pulverization equipment;

[0054] S05: Sieving and grading: The fine powder is graded through a sieve to remove oversized or undersized particles to obtain powder coating that meets the requirements;

[0055] S06: Packaging and storage: Pack the prepared powder coating and store it in a dry and cool place.

[0056] 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 low temperature curing polyester powder coating, characterized in that: The invention comprises raw materials in the following weight proportions: 46-49 parts of epoxy resin containing aromatic structure, 3-8 parts of amine curing agent, 26-30 parts of inorganic filler, 3-8 parts of pigment and 3-8 parts of auxiliary agent.

2. A low temperature curing polyester powder coating according to claim 1, characterized in that: The invention comprises raw materials in the following weight proportions: 47-48 parts of epoxy resin containing aromatic structure, 5-7 parts of amine curing agent, 27-29 parts of inorganic filler, 5-7 parts of pigment and 5-7 parts of auxiliary agent.

3. A low temperature curing polyester powder coating according to claim 1, characterized in that: The invention comprises raw materials in the following weight proportions: 47.5 parts of epoxy resin containing aromatic structure, 6 parts of amine curing agent, 28 parts of inorganic filler, 6 parts of pigment and 6 parts of auxiliary agent.

4. A method for preparing a low temperature curing polyester powder coating as claimed in any one of claims 1 to 3, characterized in that: The steps include: 1) Premixing: Add the raw materials in proportion by weight: 46-49 parts of epoxy resin containing aromatic structure, 3-8 parts of amine curing agent, 26-30 parts of inorganic filler, 3-8 parts of pigment and 3-8 parts of auxiliary agent into a high-speed mixer, premix and evenly disperse them; 2) Melt extrusion: Add the premixed materials into the extruder and melt extrude at 100-130°C; 3) Cooling and crushing: The extruded material is cooled by cooling rollers or water to solidify it into a solid, and then crushed into small particles by a crusher; 4) Fine grinding: The crushed particles are crushed into fine powder through air classification mill or other fine grinding equipment; 5) Sieving and grading: The fine powder is graded through a sieve to remove oversized or undersized particles to obtain powder coating that meets the requirements; 6) Packaging and storage: Package the prepared powder coating and store it in a dry, cool place.

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