阅读说明：本技术 一种粉末涂料及其制备和使用方法 (Powder coating and preparation and use methods thereof ) 是由 巴旭民 王治飞 张叶红 凌垄灏 于 2019-10-18 设计创作，主要内容包括：本发明公开了一种粉末涂料及其制备和使用方法,该粉末涂料包括电子束固化型聚酯树脂、颜填料和助剂,其中电子束固化型聚酯树脂、颜填料和助剂的重量比例是：电子束固化型聚酯树脂为60份到80份,颜填料为20份到40份,助剂为1份到5份。采用了本发明的技术方案,能够降低固化时所需的能耗,流程简单且无任何VOC排放,涂膜硬度高,对环境绿色友好,可用于厚达数百微米的有色涂层,能够使涂膜与底材产生化学结合提高附着力。(The invention discloses a powder coating and a preparation method and a use method thereof, the powder coating comprises electron beam curing type polyester resin, pigment and filler and an auxiliary agent, wherein the weight ratio of the electron beam curing type polyester resin to the pigment and filler to the auxiliary agent is as follows: 60 to 80 portions of electron beam curing type polyester resin, 20 to 40 portions of pigment and filler and 1 to 5 portions of auxiliary agent. By adopting the technical scheme of the invention, the energy consumption required during curing can be reduced, the process is simple, no VOC is discharged, the coating film has high hardness, is environment-friendly, can be used for a colored coating with the thickness of hundreds of micrometers, and can enable the coating film and a substrate to generate chemical combination to improve the adhesive force.)

1. The powder coating is characterized by comprising an electron beam curing type polyester resin, a pigment filler and an auxiliary agent, wherein the weight ratio of the electron beam curing type polyester resin to the pigment filler to the auxiliary agent is as follows: 60 to 80 portions of electron beam curing type polyester resin, 20 to 40 portions of pigment and filler and 1 to 5 portions of auxiliary agent.

2. The powder coating of claim 1, wherein the electron beam curable polyester resin is a modified polyester resin having a carbon-carbon double bond-C ═ C-group.

3. The powder coating of claim 1, wherein the electron beam curable polyester resin comprises a polyester acrylate, an epoxy acrylate, and/or a urethane acrylate.

4. The powder coating of claim 3, wherein the electron beam curable polyester resin is solid at normal temperature, has a glass transition temperature of 50 ℃ to 60 ℃ and a molecular weight of 5000 to 20000.

5. The powder coating of claim 1, wherein the pigments and fillers comprise barium sulfate, calcium carbonate, wollastonite, mica powder, quartz powder, carbon black, and/or titanium dioxide.

6. The powder coating of claim 1, wherein the auxiliary agent is polyacrylate, polysiloxane-polyether copolymer wetting and leveling agent, modified polysiloxane defoaming agent, silane coupling agent, acrylic phosphate and/or benzoin.

7. A process for the preparation of a powder coating according to claim 1, comprising the steps of:

mixing the electron beam curing type polyester resin, the pigment and the filler and the auxiliary agent by a mixer according to the weight ratio of 60 to 80 parts of the electron beam curing type polyester resin, 20 to 40 parts of the pigment and the filler and 1 to 5 parts of the auxiliary agent;

melting and extruding into sheets by adopting a double-screw extruder;

grinding into powder by a mill;

sieving with a 200-mesh sieve to obtain the powder coating.

8. The method of using a powder coating according to claim 1, comprising the steps of:

spraying the powder coating on the surface of a base material by using an electrostatic spray gun;

preheating for 2 minutes by adopting an infrared oven at the temperature of 120 ℃;

and curing the molten coating film by using EB (Electron Beam) curing equipment.

9. The method of claim 8, wherein the powder coating material has a curing energy of 50 kEV to 300 kEV and a dose of 10 kGy to 120 kGy.

Technical Field

The invention relates to the technical field of coatings, in particular to a powder coating and a preparation method and a use method thereof.

Background

At present, products such as MDF plates, thermoplastic substrates, coiled steel aluminum materials and the like are increasingly decorated and protected by adopting coatings, and the coatings applied to the materials sold in the market are solvent-based thermosetting coatings, and the coatings have the problems of high VOC (volatile organic compound) emission, pungent odor, environmental pollution, high energy consumption and the like.

If UV light is used to cure the powder coating, it is necessary to introduce photoinitiators, the residues of which and the products of the photodecomposition can volatilize and give rise to unpleasant odours.

Disclosure of Invention

In order to overcome the problems in the related art, the embodiment of the invention provides a powder coating and a preparation and use method thereof, which reduce the energy consumption required during curing, have simple process, no VOC emission, high coating hardness and environmental friendliness, can be used for a colored coating with the thickness of hundreds of micrometers, and can enable the coating and a substrate to generate chemical combination to improve the adhesive force.

One aspect of an embodiment of the present invention provides a powder coating, including an Electron Beam (EB) curable polyester resin, a pigment, a filler, and an additive, where the weight ratio of the Electron Beam curable polyester resin, the pigment, the filler, and the additive is: 60 to 80 portions of electron beam curing type polyester resin, 20 to 40 portions of pigment and filler and 1 to 5 portions of auxiliary agent.

Further, the electron beam-curable polyester resin is a modified polyester resin having a carbon-carbon double bond-C ═ C-group.

Further, the electron beam curing type polyester resin includes polyester acrylate, epoxy acrylate and/or urethane acrylate.

Further, the electron beam curing type polyester resin is solid at normal temperature, has a glass transition temperature of 50 ℃ to 60 ℃ and a molecular weight of 5000 to 20000.

Further, the pigment and filler comprises barium sulfate, calcium carbonate, wollastonite, mica powder, quartz powder, carbon black and/or titanium dioxide.

Further, the auxiliary agent is polyacrylate, polysiloxane-polyether copolymer wetting and leveling agent, modified polysiloxane defoaming agent, silane coupling agent, acrylic phosphate and/or benzoin.

In another aspect, the present invention provides a method for preparing a powder coating, including the following steps:

mixing the electron beam curing type polyester resin, the pigment and the filler and the auxiliary agent by a mixer according to the weight ratio of 60 to 80 parts of the electron beam curing type polyester resin, 20 to 40 parts of the pigment and the filler and 1 to 5 parts of the auxiliary agent;

melting and extruding into sheets by adopting a double-screw extruder;

grinding into powder by a mill;

sieving with a 200-mesh sieve to obtain the powder coating.

In another aspect, embodiments of the present invention provide a method for using a powder coating, including the steps of:

spraying the powder coating on the surface of a base material by using an electrostatic spray gun;

preheating for 2 minutes by adopting an infrared oven at the temperature of 120 ℃;

and curing the molten coating film by using EB (Electron Beam) curing equipment.

Further, the powder coating has a curing energy of 50 kilo-electron-volts (keV) to 300 kilo-electron-volts (keV) and a dose of 10 kilograys (kGy) to 120 kilograys (kGy).

The technical scheme provided by the embodiment of the invention has the following beneficial effects:

1. the storage and the transportation are convenient. The traditional coating is in a liquid state at normal temperature, and the sealing work is required for storage, processing and transportation, and the great potential safety hazard exists. And the EB curing powder coating is solid powder at normal temperature, is simple and convenient to transport, store and process and has high safety.

2. The EB curing powder coating is green and environment-friendly, does not contain any organic solvent, can really realize zero VOC emission, and has no pollution to the environment.

3. EB curing powder coating can realize low-temperature rapid curing, the early-stage infrared preheating only needs about 120 ℃ to melt and level, the later-stage curing under EB electron beam irradiation only needs about 5 seconds or less, and the traditional solvent type thermosetting coating needs about 200 ℃ high temperature curing for about 30 seconds.

4. EB solidification powder coating manufacture equipment is convenient and compact, the process flow is simple, and the work of each flow can be completed in a smaller space, so that the intensification of resources is realized, and the EB solidification powder coating manufacture equipment is further applied to the wider field.

5. Compared with the UV light curing coating, the EB curing powder coating does not need to introduce a photoinitiator, and can effectively reduce the formula cost. When cured into a film, the composition does not cause unpleasant odor due to volatilization of the initiator and its decomposition products, and thus can be used in the fields related to food safety. EB curing allows penetration of thicker film layers, enabling curing of thicker coatings than UV light curable coatings.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention, as claimed.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the invention and together with the description, serve to explain the principles of the invention.

FIG. 1 is a flow chart of powder coating preparation in an example of the present invention.

FIG. 2 is a flow chart of powder coating application in an example of the present invention.

Detailed Description

Reference will now be made in detail to the exemplary embodiments, examples of which are illustrated in the accompanying drawings. When the following description refers to the accompanying drawings, like numbers in different drawings represent the same or similar elements unless otherwise indicated. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present invention. Rather, they are merely examples of apparatus, and associated applications, methods consistent with certain aspects of the invention, as detailed in the following claims.

The embodiment of the invention provides an EB (Epstein-Barr) curing-based powder coating for MDF (medium density fiberboard) plates, thermoplastic substrates and coiled steel aluminum materials, which is quickly cured at low temperature and comprises EB curing type polyester resin, pigments, fillers and auxiliaries.

Wherein the weight ratio of the EB curing type polyester resin, the pigment filler and the auxiliary agent is as follows: 60 to 80 portions of EB curing type polyester resin, 20 to 40 portions of pigment and filler and 1 to 5 portions of auxiliary agent.

The EB curing type polyester resin is modified polyester resin with carbon-carbon double bond-C ═ C-group, and the basic component is one of various polyester acrylates, including polyester acrylate, epoxy acrylic resin and/or polyurethane acrylate.

The basic synthesis way is that one or more of terephthalic acid, isophthalic acid, hexanediol, neopentyl glycol, ethylene glycol, diethylene glycol, trimethylolpropane, propylene glycol and the like are added into reaction raw materials at the temperature of 250 ℃, and the alcohol-acid ratio is ensured to be between 1.01 and 1.08; and after the reaction is finished, adding an acrylic monomer for end capping, cooling and crushing to finally obtain the EB (ethylene-boron) curing type polyester resin. The synthetic polyester resins are generally of the formula:

the EB curing type polyester resin is solid at normal temperature, the glass transition temperature is between 50 ℃ and 60 ℃, and the molecular weight is between 5000 and 20000.

The pigment and filler comprises barium sulfate, calcium carbonate, wollastonite, mica powder, quartz powder, carbon black and/or titanium dioxide.

The auxiliary agent is polyacrylate, polysiloxane-polyether copolymer wetting and leveling agent, modified polysiloxane defoaming agent, silane coupling agent, acrylic phosphate and/or benzoin.

FIG. 1 is a flow chart of powder coating preparation in an example of the present invention. As shown in fig. 1, the preparation process of the EB-cured based powder coating includes the following steps:

101, mixing 60 to 80 parts of EB (Epstein-Barr) curing type polyester resin, 20 to 40 parts of pigment and filler and 1 to 5 parts of auxiliary agent by a mixer according to the weight proportion.

And step 102, adopting a double-screw extruder to melt and extrude the mixture into sheets.

103, grinding into powder by a grinder.

And step 104, sieving the mixture by using a 200-mesh sieve to prepare the powder coating.

FIG. 2 is a flow chart of powder coating application in an example of the present invention. As shown in fig. 2, the usage flow of the EB-cured based powder coating includes the following steps:

step 201, spraying the powder coating solidified based on EB on the surface of the base material by using an electrostatic spray gun.

Step 202, preheating for 2 minutes by using an infrared oven at the temperature of 120 ℃.

And step 203, solidifying the melted coating film by using EB solidification equipment.

The curing energy of the powder coating cured on the basis of EB is from 50 kilo-electron volts (keV) to 300 kilo-electron volts (keV) at a dose of from 10 kilograys (kGy) to 120 kilograys (kGy).

The compositional comparison between the EB-cured powder coating and the existing coating is detailed in table 1.

TABLE 1

Formulation of	Traditional powder coating	UV-curable powder coating	EB cured powder coating
				Ordinary polyester resin	70	/	/
UV-curable polyester resin	/	70	/
				EB curing polyester resin	/	/	70
Auxiliary agent	5	5	5
				Pigment and filler	25	25	25
Total amount of	100	100	100

The comparison of the effect between powder coatings cured on the basis of EB and the existing coatings is shown in Table 2.

TABLE 2

According to the experimental data, the powder coating based on EB curing in the embodiment of the invention has the advantages of high efficiency, energy conservation, economy, environmental protection and the like, can replace the traditional solvent type thermosetting coating, the traditional thermosetting powder coating and the UV curing coating, and is applied to the fields of MDF plates, thermoplastic substrates, coiled steel aluminum materials and the like, thereby effectively reducing the production energy consumption, improving the production efficiency and reducing the waste emission during production.

Other embodiments of the invention will be apparent to those skilled in the art from consideration of the specification and practice of the invention disclosed herein. This application is intended to cover any variations, uses, or adaptations of the invention following, in general, the principles of the invention and including such departures from the present disclosure as come within known or customary practice within the art to which the invention pertains.

It will be understood that the invention is not limited to the precise arrangements described above and shown in the drawings and that various modifications and changes may be made without departing from the scope thereof. The scope of the invention is limited only by the appended claims.