阅读说明：本技术 一种废旧粉末涂料再生阻燃塑料颗粒的工艺方法 (Process method for regenerating flame-retardant plastic particles from waste powder coating ) 是由 蒋娜 于 2020-06-24 设计创作，主要内容包括：本发明公开了一种废旧粉末涂料再生阻燃塑料颗粒的工艺方法,本发明属于再生塑料技术领域,制备的再生塑料颗粒有明显的成本优势,尤其是近来塑料原料价格的飞涨,使市场对再生料的需求进一步提高,本发明可以大幅度解决此类需求,利用废旧粉末涂料资源化过程中物质能量的转化与代谢规律,再生的过程并不包括以往再生塑料颗粒的熔融挤压成型造粒,降低了挤出机等设备的高昂造价和复杂的工艺程序,节约人工,大幅度降低人工和成本,制得的再生塑料颗粒具有极高的经济附加价值。(The invention discloses a process method for regenerating flame-retardant plastic particles by waste powder coating, which belongs to the technical field of regenerated plastics, wherein the prepared regenerated plastic particles have obvious cost advantage, especially the recent plastic raw material price is increased, so that the demand of the market on the regenerated materials is further improved.)

1. A process method for regenerating flame-retardant plastic particles from waste powder coating is characterized by comprising the following steps:

modifying the waste powder coating: stripping the waste powder coating on the coating surface; crushing and dispersing by using a dispersing agent, and then removing iron by using an electromagnetic iron remover to obtain clean waste powder coating; the waste powder coating comprises the following components: polyester powder coating, polyacrylate powder coating, polyvinyl chloride powder coating, polyethylene powder coating, nylon powder coating, polyvinylidene fluoride powder coating, or a part of the above-mentioned multiple components; (2) carrying out settlement impurity removal and dispersion modification on the waste powder coating obtained in the step (1) to obtain a modified mixture; the specific modification process comprises the steps of (1) immersing the clean waste powder coating obtained in the step (1) into a sedimentation tank containing water with the weight 1-1.3 times of the weight of the clean waste powder coating, precipitating the clean waste powder coating with water, adding an inorganic dispersion treatment agent with the weight 0.05-0.1 time of the weight of the clean waste powder coating into the sedimentation tank, uniformly stirring for 10-20 min, standing for 12-14 h, removing impurities floating on the sedimentation tank, adding dry ice with the weight 0.05-0.1 time of the weight of the clean waste powder coating, uniformly stirring, filtering sediments below the water surface, recovering to obtain the settled waste powder coating, carrying out centrifugal dehydration treatment, drying at 70-80 ℃ until the water content is 0.1-0.3%, and uniformly mixing with a degumming agent with the weight 0.05-0.1 time of the settled waste powder coating to obtain the dehydrated waste powder coating; (3) adding waste powder paint which is 0.2-0.4 time of the total weight of the dehydrated waste powder paint and ionic liquid which is 0.5-0.8 time of the weight of the dehydrated waste powder paint into a high-speed mixer, uniformly mixing at normal temperature, heating plasticizer which is 0.5-0.8 time of the weight of the dehydrated waste powder paint to 150-155 ℃, adding the mixture into a uniformly-mixed high-speed mixer, continuously stirring, and changing the material into semitransparent and uniform paste while the material temperature gradually decreases; when the temperature of the paste is reduced to 55-65 ℃, adding the rest of the dehydrated waste powder coating and a toughening agent which is 0.05-0.07 time of the weight of the rest of the dehydrated waste powder coating, mixing and stirring uniformly to obtain a plastic paste, defoaming, carrying out vacuum pressure reduction, pouring the plastic paste into a defoaming Buchner funnel, enabling the plastic paste to drop by drops, removing air in the paste by using the vacuum effect, placing a clean slush molding mould into a constant-temperature blast oven at 160-170 ℃, heating for 5-10 min, and taking out to obtain a plastic sheet; (4) and uniformly cutting the plastic sheets into particles to obtain the regenerated plastic particles.

2. The process method for regenerating flame-retardant plastic particles from waste powder coating as claimed in claim 1, wherein the inorganic dispersing agent is one or more of calcium oxide, sodium hydroxide or aluminum trichloride.

3. The process of claim 1, wherein the toughening agent is ball clay and/or sericite powder.

4. The process method for regenerating flame-retardant plastic particles from waste powder coating according to claim 1, wherein the formula of the degumming agent comprises the following components in parts by weight: 5-6 parts of xylitol, 45-50 parts of hydrogenated castor oil, 5-6 parts of aluminum oxide, 5-6 parts of sodium zirconium lactate, 2-4 parts of methyl cellulose, 3-5 parts of sodium dioctyl sulfosuccinate and 2-4 parts of hydroxypropyl cellulose.

5. The process method for regenerating the flame-retardant plastic particles from the waste powder coating according to claim 1, wherein the plasticizer is one or more selected from methoxy ethanol ricinoleate, diisopropyl tartrate and tripentyl citrate.

6. The process of claim 1, wherein the ionic liquid is one of quaternary ammonium ionic liquid and pyridine ionic liquid, the quaternary ammonium ionic liquid is one of tributylmethylammonium bis (trifluoromethanesulfonyl) imide salt, tributylmethylammonium chloride and N-methoxyethyl-N-methyldiethylammonium tetrafluoroborate, and the pyridine ionic liquid is one of N-butylpyridinium tetrafluoroborate, N-butylpyridinium bis (trifluoromethanesulfonyl) imide salt and N-butylpyridinium tetrafluoroborate.

Technical Field

The invention belongs to the technical field of recycled plastics, and particularly relates to a process method for recycling flame-retardant plastic particles from waste powder coating.

Background

The powder coating is a solid powder synthetic resin coating composed of solid resin, pigment, filler, auxiliary agent and the like. Unlike conventional solvent-based coatings and water-based coatings, the dispersion medium is not a solvent and water, but air. It has the characteristics of no solvent pollution, 100 percent film forming and low energy consumption. However, the manufacturing equipment of the powder coating can not directly use the manufacturing equipment of the solvent-based or water-based coating, and special equipment for manufacturing the powder coating is required, so that the problem of color matching is the most difficult in the manufacturing process of the powder coating, different from the color matching method of the solvent-based or water-based coating, color paste or toner can not be used for directly matching colors, the color matching time is long, some texture types can not use color matching instruments, only depending on experience, the color matching is troublesome, and the recoating is caused by frequent errors. In the process of manufacturing and coating the powder coating, resin change and color variety are troublesome. Powder coatings are generally suitable for thick coats. The baking temperature of the powder coating is relatively high, generally more than 150 ℃, and mostly between 180 and 200 ℃, and the powder coating is not suitable for coating of base materials such as plastic, wood, paper and the like with poor heat resistance. And is not suitable for coating heat-labile articles such as soldering tin parts, electronic components and the like. In the current market, a large amount of waste plastics are recycled to manufacture coatings, and various technologies are disclosed, but the waste plastics of a single variety are generally used as basic raw materials of the coatings, particularly the waste polystyrene plastics. However, in the current market, the relevant product and corresponding technology for the preparation of recycled plastic granules from powder coatings may be called phoenix-bone unicorn. Waste powder coatings, which are one of the waste products, are very difficult to handle because they are in a sticky state after aging and breakage, and various powder coating plants are actively developing methods for improving the coating properties of powder coatings and technologies for recycling waste powder coatings in order to reduce the amount of waste powder coatings. With the advent of China, household electrical appliances and other industrial products are developed towards the aspect of environment-friendly powder coating, and the use amount of the powder coating is extremely large, so that the recycling work of the powder coating is more important. During the production and coating process of the powder coating, parts of the powder coating are attached to the inner wall of the equipment or settle at the bottom of the equipment under the influence of factors such as process equipment and the like, and the components are collectively called recycled powder. Powder coatings are not recycled powders, which have already been coated. The waste powder coating is a waste powder coating paint which is subjected to irreversible processes such as aging, breakage and the like after being coated. The technical personnel in the field need to develop a process method for regenerating flame-retardant plastic particles from waste powder coating to realize continuous recovery and obtain regenerated plastic particles for other purposes through regeneration treatment so as to obtain higher economic added value and environmental protection benefit.

Disclosure of Invention

The invention aims to provide a process method for regenerating flame-retardant plastic particles from waste powder coating aiming at the existing problems.

A process method for regenerating flame-retardant plastic particles from waste powder coating comprises the following steps:

(1) modifying the waste powder coating: stripping the waste powder coating on the coating surface; crushing and dispersing by using a dispersing agent, and then removing iron by using an electromagnetic iron remover to obtain clean waste powder coating; the waste powder coating comprises the following components: polyester powder coating, polyacrylate powder coating, polyvinyl chloride powder coating, polyethylene powder coating, nylon powder coating, polyvinylidene fluoride powder coating, or a part of the above-mentioned multiple components; (2) carrying out settlement impurity removal and dispersion modification on the waste powder coating obtained in the step (1) to obtain a modified mixture; the specific modification process comprises the steps of (1) immersing the clean waste powder coating obtained in the step (1) into a sedimentation tank containing water with the weight 1-1.3 times of the weight of the clean waste powder coating, precipitating the clean waste powder coating with water, adding an inorganic dispersion treatment agent with the weight 0.05-0.1 time of the weight of the clean waste powder coating into the sedimentation tank, uniformly stirring for 10-20 min, standing for 12-14 h, removing impurities floating on the sedimentation tank, adding dry ice with the weight 0.05-0.1 time of the weight of the clean waste powder coating, uniformly stirring, filtering sediments below the water surface, recovering to obtain the settled waste powder coating, performing centrifugal dehydration, drying at 70-80 ℃ until the water content is 0.1-0.3%, and uniformly mixing with a degumming agent with the weight 0.05-0.1 time of the settled waste powder coating to obtain the dehydrated waste powder coating; (3) adding waste powder paint which is 0.2-0.4 time of the total weight of the dehydrated waste powder paint and ionic liquid which is 0.5-0.8 time of the weight of the dehydrated waste powder paint into a high-speed mixer, uniformly mixing at normal temperature, heating plasticizer which is 0.5-0.8 time of the weight of the dehydrated waste powder paint to 150-155 ℃, adding the mixture into a uniformly-mixed high-speed mixer, continuously stirring, and changing the material into semitransparent and uniform paste while the material temperature gradually decreases; when the temperature of the paste is reduced to 55-65 ℃, adding the rest of the dehydrated waste powder coating and a toughening agent which is 0.05-0.07 time of the weight of the rest of the dehydrated waste powder coating, mixing and stirring uniformly to obtain a plastic paste, defoaming, carrying out vacuum pressure reduction, pouring the plastic paste into a defoaming Buchner funnel, enabling the plastic paste to drop by drops, removing air in the paste by using the vacuum effect, placing a clean slush molding mould into a constant-temperature blast oven at 160-170 ℃, heating for 5-10 min, and taking out to obtain a plastic sheet; (4) and uniformly cutting the plastic sheets into particles to obtain the regenerated plastic particles.

In a further scheme, the inorganic dispersion treatment agent is one or more of calcium oxide, sodium hydroxide or aluminum trichloride.

In a further scheme, the toughening agent is ball clay and/or sericite powder.

In a further scheme, the formula of the degumming agent comprises the following components in parts by weight: 5-6 parts of xylitol, 45-50 parts of hydrogenated castor oil, 5-6 parts of aluminum oxide, 5-6 parts of sodium zirconium lactate, 2-4 parts of methyl cellulose, 3-5 parts of sodium dioctyl sulfosuccinate and 2-4 parts of hydroxypropyl cellulose.

In a further scheme, the plasticizer is selected from one or more of methoxy ethanol ricinoleate, diisopropyl tartrate and tripentyl citrate.

In a further scheme, the ionic liquid is one of a quaternary ammonium ionic liquid and a pyridine ionic liquid, the quaternary ammonium ionic liquid is selected from one of tributyl methyl ammonium bis (trifluoromethanesulfonyl) imide salt, tributyl methyl ammonium chloride and N-methoxyethyl-N-methyl diethyl ammonium tetrafluoroborate, and the pyridine ionic liquid is selected from one of N-butyl pyridine tetrafluoroborate, N-butyl pyridine bis (trifluoromethanesulfonyl) imide salt and N-butyl pyridine tetrafluoroborate.

The invention has the beneficial effects that:

the regenerated plastic particles prepared by the process method remove the water, impurities and solvent components contained in the waste powder coating, so that the hard polymer components of the resin are degummed and are changed into the renewable active powder through dissociation. The treatment in the sedimentation tank is characterized in that degumming agent degumming treatment is carried out between a cleaning process and an impurity removal process and an inorganic dispersion treatment process, so that the treatment capacity and the powder quality are effectively improved. The inorganic dispersion treatment agent can eliminate bacteria and harmful microorganisms in the waste powder coating, so that regenerated plastic particles are sanitary, clean and harmless, for example, the addition of the calcium oxide inorganic dispersion treatment agent improves alkalinity and generates hydrothermal reaction, the waste powder coating is subjected to further dispersion treatment by heat release and then reacts with dry ice to generate calcium carbonate capable of improving strength and flame retardance, the temperature is reduced by the addition of the dry ice, the powder coating is further subjected to dispersion treatment by cold and hot alternate treatment, and the powder coating is subjected to plasticizing and degumming agent in the spraying process, so that the effect of an organic solvent on dissolution and swelling is mainly utilized to remove the residual partial cross-linked structure on the surface of a substrate. When the powder coating is changed into the waste powder coating, the degumming agent treatment and use are convenient, the degumming efficiency is high, and the degumming agent is different from common melt extrusion regeneration granulation, hydrogenated castor oil has the functions of permeating into gaps of macromolecular chain segments of a coating film to soften, swell or dissolve the coating film, has larger compatibility and good permeation energy, and can quickly and effectively soften the waste powder coating, wherein the hydrogenated castor oil has small molecular weight and strong permeation capability, can permeate into the gaps of the macromolecular chain segments of a high polymer of the coating film to reduce intermolecular force, and xylitol has the function of forming a binary azeotrope with the hydrogenated castor oil at lower temperature to play the role of the compatibilizer to promote the hydrogenated castor oil to fully permeate into the coating film, enhance the peptization capability, accelerate the degumming speed, and the price of the xylitol is low, so that the cost can be reduced. Sodium zirconium lactate and methylcellulose are used for activating in order to improve the degumming efficiency. Sodium dioctyl sulfosuccinate and hydroxypropyl cellulose, aiming at increasing the viscosity of the degumming agent, reducing the fluidity of the degumming agent and reducing the agglomeration phenomenon of powder coating particles, and the aluminum oxide aims at emulsifying water in the degumming agent, uniformly dispersing the degumming agent and improving the consistency of the degumming agent. The components in the degumming agent can play a good role in processing in the process of forming the plastic paste, the aluminum oxide can improve the strength and the wear resistance, and the xylitol, the sodium zirconium lactate, the methyl cellulose and the like can improve the processing rheological property. The ionic liquid and the plasticizer are adopted, the acting force between macromolecules is reduced, the plastic sheet is prepared by forming plastic, cutting granulation is carried out, energy is saved, the stability of regenerated plastic particles is ensured, over-molding is avoided, and the processing performance is good. The toughening agent improves the toughness and the impact strength of the regenerated plastic particles, and has low price, wide source and easy acquisition.

Compared with the prior art, the invention has the following advantages:

the recycled flame-retardant plastic particles prepared by the process method disclosed by the invention are frequently in a coarse particle state, and generally cannot be reused because the quality of the recycled powder produced by a powder factory cannot meet the spraying requirement. In the prior art, a large amount of waste powder coating is abandoned, and the regenerated plastic particles are also freshly prepared from a coating waste material source, the invention not only opens up a novel way for preparing the regenerated plastic particles from the waste coating, but also has obvious cost advantage, especially the recent rise of the price of the plastic raw material further strengthens the requirement of the market on the regenerated material, the invention can greatly solve the transformation and metabolism law of the material energy in the process of recycling the waste powder coating by utilizing the requirement, the regeneration process does not include the conventional fusion extrusion molding granulation of the regenerated plastic particles, the high manufacturing cost and the complex process procedures of equipment such as an extruder and the like are reduced, the labor is saved, the labor and the cost are greatly reduced, and the prepared regenerated plastic particles have extremely high economic additional value.

Detailed Description

The invention is illustrated by the following specific examples, which are not intended to be limiting.