阅读说明：本技术 不含尘的热固性粉末涂料及制备方法 (Thermosetting powder coating without dust and preparation method thereof ) 是由 周兰康 黄玉立 于 2021-08-02 设计创作，主要内容包括：本发明提供一种不含尘的热固性粉末涂料,按重量份数计包括以下组分：树脂50-60份、偶联剂0.5-1.5份、固化剂4-5份、颜料10-20份、助剂6-8份和填料15-20份。所述树脂采用端羟基不饱和聚酯树脂；所述偶联剂采用硅烷偶联剂；所述固化剂选自异氰尿酸三缩水甘油酯、多元苯甲酸缩水甘油酯中的一种或多种；所述颜料为造粒碳黑；所述助剂为流平剂、脱气剂、松散剂、抗氧化剂、消泡剂中的一种或几种以上混合；所述填料为硬酯酸。本发明还提供一种不含尘的热固性粉末涂料制备方法；以前粉末涂料制备行业生产过程会制造大量灰尘,后续在涂料过程也会有大量有害粉尘。采用本发明不含尘的热固性粉末涂料,即没有PM2.5,也没有了PM10,彻底解决了粉尘污染的问题。(The invention provides a dust-free thermosetting powder coating which comprises the following components in parts by weight: 50-60 parts of resin, 0.5-1.5 parts of coupling agent, 4-5 parts of curing agent, 10-20 parts of pigment, 6-8 parts of auxiliary agent and 15-20 parts of filler. The resin is hydroxyl-terminated unsaturated polyester resin; the coupling agent is a silane coupling agent; the curing agent is selected from one or more of triglycidyl isocyanurate and poly-glycidyl benzoate; the pigment is granulated carbon black; the auxiliary agent is one or more of a leveling agent, a degassing agent, a dispersing agent, an antioxidant and a defoaming agent; the filler is stearic acid. The invention also provides a preparation method of the thermosetting powder coating without dust; in the prior art, a large amount of dust is produced in the production process of the powder coating preparation industry, and a large amount of harmful dust is produced in the subsequent coating process. By adopting the thermosetting powder coating without dust, namely PM2.5 and PM10 are not generated, and the problem of dust pollution is thoroughly solved.)

1. A dust-free thermosetting powder coating, characterized in that: the paint comprises the following components in parts by weight:

50-60 parts of resin, 0.5-1.5 parts of coupling agent, 4-5 parts of curing agent, 10-20 parts of pigment, 6-8 parts of auxiliary agent and 15-20 parts of filler.

2. A dust-free thermosetting powder coating according to claim 1, characterized in that:

the resin is hydroxyl-terminated unsaturated polyester resin;

the coupling agent is a silane coupling agent;

the curing agent is selected from one or more of triglycidyl isocyanurate and poly-glycidyl benzoate;

the pigment is granulated carbon black;

the auxiliary agent is one or more of a leveling agent, a degassing agent, a dispersing agent, an antioxidant and a defoaming agent;

the filler is stearic acid.

3. A dust-free thermosetting powder coating according to claim 2, characterized in that: the paint comprises the following components in parts by weight:

55 parts of resin, 1 part of coupling agent, 4.5 parts of curing agent, 7 parts of auxiliary agent, 15 parts of pigment and 17.5 parts of filler.

4. A dust-free thermosetting powder coating according to claim 3, characterized in that:

the particle size of the resin is more than 10 microns;

the coupling agent is a liquid;

the grain size of the curing agent is more than 10 microns;

the particle size of the auxiliary agent is more than 10 microns;

the particle size of the pigment is more than 10 microns;

the particle size of the stearic acid is more than 10 microns.

5. Process for the preparation of a dust-free thermosetting powder coating according to any one of claims 1 to 4, characterized in that: the method comprises the following steps:

step 1), batching, namely batching according to a formula;

step 2), grinding, and adjusting the grinding and feeding speed, the grinding disc rotating speed and the discharging speed;

step 3), during cyclone separation, increasing centrifugal force and removing most fine dust;

step 4), screening out the remaining small part of the fine dust of the leaking net by using an ultrasonic vibration sieve;

and 5) detecting whether the particle size is qualified by using a laser particle size analyzer.

6. A process for the preparation of a thermosetting powder coating material free of dust according to claim 5, characterized in that:

the step 2) comprises the following steps:

2.1), feeding by frequency conversion control, slowly and uniformly feeding, wherein the frequency conversion control is between 22 and 27 Hz;

2.2), controlling the speed of the grinding disc by using variable frequency, wherein the variable frequency is controlled at 45 Hz;

2.3) accelerating the discharging speed, and controlling the frequency conversion between 18 and 20 Hz.

7. A process for the preparation of a non-dusting thermosetting powder coating according to claim 6, characterized in that:

in step 4):

and (3) if fine powder is screened out from the screened channel, continuously increasing the centrifugal force of the cyclone separation in the step 3) until no fine powder is screened out from the channel.

8. A process for the preparation of a thermosetting powder coating material free of dust according to claim 7, characterized in that:

in step 5):

detecting by a laser particle size analyzer to obtain actually measured particle size distribution, and if the content of particles with the particle size of less than 10 microns is higher than 0.01%, determining that the particles contain dust and are unqualified; if the content of the particles with the particle size of less than 10 micrometers is less than or equal to 0.01 percent, the dust-free glass is judged to be not dusty and qualified.

Technical Field

The invention relates to a thermosetting powder coating, in particular to a dust-free thermosetting powder coating and a preparation method thereof.

Background

Thermosetting powder coatings are considered one of the most environmentally friendly coatings due to their zero VOC emission. The development of thermosetting powder coatings is very supported by related departments nowadays, the construction department is promoted to appoint the thermosetting powder coatings and the environment-friendly coatings to be used for aluminum alloy doors and windows without consuming tax, and the like, and particularly, the modern countries advocate the powder for improving the paint (oil to powder).

Thermosetting powder coatings, however, also have environmental disadvantages, which result in a large amount of dust, and thermosetting powder coatings contain a large amount of dust (PM2.5, PM10) particles. The methods adopted by the prior art aiming at the problem are filtration, dust collection and personal protection increase, but the effect is not ideal.

Accordingly, there is a need for improvements in the art.

Disclosure of Invention

The invention aims to provide a high-efficiency dust-free thermosetting powder coating and a preparation method thereof.

In order to solve the technical problem, the invention provides a dust-free thermosetting powder coating which comprises the following components in parts by weight:

50-60 parts of resin, 0.5-1.5 parts of coupling agent, 4-5 parts of curing agent, 10-20 parts of pigment, 6-8 parts of auxiliary agent and 15-20 parts of filler.

As an improvement to the dust-free thermosetting powder coating of the present invention:

the resin is hydroxyl-terminated unsaturated polyester resin;

the coupling agent is a silane coupling agent;

the curing agent is selected from one or more of triglycidyl isocyanurate and poly-glycidyl benzoate;

the pigment is granulated carbon black;

the auxiliary agent is one or more of a leveling agent, a degassing agent, a dispersing agent, an antioxidant and a defoaming agent;

the filler is stearic acid.

As an improvement to the dust-free thermosetting powder coating of the present invention:

55 parts of resin, 1 part of coupling agent, 4.5 parts of curing agent, 7 parts of auxiliary agent, 15 parts of pigment and 17.5 parts of filler.

As an improvement to the dust-free thermosetting powder coating of the present invention:

the particle size of the resin is more than 10 microns;

the coupling agent is a liquid;

the grain size of the curing agent is more than 10 microns;

the particle size of the auxiliary agent is more than 10 microns;

the particle size of the pigment is more than 10 microns;

the particle size of the stearic acid is more than 10 microns.

The invention also provides a preparation method of the thermosetting powder coating without dust, which comprises the following steps:

step 1), batching, namely batching according to a formula;

step 2), grinding, and adjusting the grinding and feeding speed, the grinding disc rotating speed and the discharging speed;

step 3), during cyclone separation, increasing centrifugal force and removing most fine dust;

step 4), screening out the remaining small part of the fine dust of the leaking net by using an ultrasonic vibration sieve;

and 5) detecting whether the particle size is qualified by using a laser particle size analyzer.

As an improvement to the process for the preparation of the dust-free thermosetting powder coatings of the present invention:

the step 2) comprises the following steps:

2.1), feeding by frequency conversion control, slowly and uniformly feeding, wherein the frequency conversion control is between 22 and 27 Hz;

2.2), controlling the speed of the grinding disc by using variable frequency, wherein the variable frequency is controlled at 45 Hz;

2.3) accelerating the discharging speed, and controlling the frequency conversion between 18 and 20 Hz.

As an improvement to the process for the preparation of the dust-free thermosetting powder coatings of the present invention:

in step 4):

and (3) if fine powder is screened out from the screened channel, continuously increasing the centrifugal force of the cyclone separation in the step 3) until no fine powder is screened out from the channel.

As an improvement to the process for the preparation of the dust-free thermosetting powder coatings of the invention in step 5):

detecting by a laser particle size analyzer to obtain actually measured particle size distribution, and if the content of particles with the particle size of less than 10 microns is higher than 0.01%, determining that the particles contain dust and are unqualified; if the content of the particles with the particle size of less than 10 micrometers is less than or equal to 0.01 percent, the dust-free glass is judged to be not dusty and qualified.

The thermosetting powder coating without dust and the preparation method thereof have the technical advantages that:

although the toughness of the particles is properly changed by removing less than 10 percent of superfine part (less than 10 microns), a plurality of properties of the dust-free thermosetting powder coating are obviously or radically changed; the method specifically comprises the following steps:

1) the loss of the ACM mill is greatly reduced, and the most energy-consuming grinding disc and the most consumption of grinding columns are not large particles but the smallest particles of repeated grinding during grinding;

2) the consistency of the product is improved very significantly while ensuring a greater concentration of the particles of size, in particular when the thermosetting powder coating is applied by spraying, substantially without falling off (recycling of powder) similar to that of the prior art;

3) the cleaning of dust collecting equipment is reduced, and because the thermosetting powder coating without dust does not have dust, the dust collecting equipment does not need to be cleaned in the day like before in the using process;

4) the high-voltage electrostatic spraying can be used on dead corners, and the powder particles with positive charges can be caused (electrostatic shielding) at the dead corners due to the Faraday effect and are free of dust, so that the problem cannot be solved in the prior art. The invention has the advantages that electrostatic shielding can be effectively avoided by adopting the dust-free thermosetting powder coating, and charged particles in the powder with the same weight are only 1/3 of the existing thermosetting powder coating, so that the electrostatic shielding at dead corners is effectively avoided;

5) the production process of the previous powder coating preparation industry can produce a large amount of dust, and a large amount of harmful dust can be produced in the subsequent coating process. By adopting the dust-free thermosetting powder coating, namely PM2.5 and PM10 are not generated, and the problem of dust pollution is thoroughly solved.

Drawings

The following describes embodiments of the present invention in further detail with reference to the accompanying drawings.

FIG. 1 is a schematic representation of the effects of a prior art thermosetting powder coating;

FIG. 2 is a schematic representation of the effect of the dust-free thermosetting powder coating of the present invention.

Detailed Description

The invention will be further described with reference to specific examples, but the scope of the invention is not limited thereto.

Example 1, thermosetting powder coating without dust, aiming at the drawbacks of the prior art, it is envisaged to solve the problem at the source, by making the powder coating free of dust, i.e. with finest particles greater than 10 microns (PM2.5 ═ 0, PM10 ═ 0).

Firstly, in the formula, the dosage of fine particles is reduced, and the fine particle raw materials such as calcium carbonate, grinding pigment, superfine wax, fine carbon black and the like are used or not used, but the wrapping filler, the granular carbon black, the polymerized wax and the resin with better wrapping property are used.

The thermosetting powder coating without dust comprises resin, a coupling agent, a curing agent, pigment (which can contain fine powder), an auxiliary agent (which can contain fine powder) and filler (which can contain no fine powder).

The resin is hydroxyl-terminated unsaturated polyester resin;

the coupling agent is a silane coupling agent;

the curing agent is selected from one or more of triglycidyl isocyanurate and poly-glycidyl benzoate;

the pigment is granulated carbon black;

the auxiliary agent is one or more of a flatting agent, a degassing agent, a dispersing agent, an antioxidant and a defoaming agent;

the filler is stearic acid.

The pigment and the auxiliary agent can be selected from dust and coarse materials, and the effect of the coarse materials is better.

The filler is fine (dust) material, and the wrapping dust-free material is needed.

The concrete components are as follows (by weight portion):

and (3) carrying out classification and screening after grinding, aiming at a small amount of generated fine particles below 10 micrometers, using multiple times of separation, increasing centrifugal force, increasing cyclone separation strength, sieving by using a high-number ultrasonic screen, and the like to ensure that the finished product does not contain the fine particles below 10 micrometers. And the quality of the product is ensured by using a laser particle analyzer for detection.

The preparation method comprises the following steps:

step 1), batching, namely batching according to a formula;

step 2), reducing the grinding grading speed during grinding;

during grinding, the grinding and feeding speed, the grinding disc rotating speed and the discharging speed need to be adjusted.

2.1) feeding is controlled by frequency conversion, slow and uniform feeding is achieved, and the frequency conversion control is proper between 22 and 27 Hz.

2.2) and the speed of the grinding disc is also controlled by frequency conversion, and is optimally controlled at 45 Hz.

2.3) discharging (grading) is reduced, namely the discharging speed must be high, residual materials cannot be left in the grinding chamber, the discharging speed is too low, the contact time between the grinding disc and the materials to be grinded is unstable, the content of fine powder to be separated is not high or low, and the subsequent treatment is influenced. It is generally sufficient to set between 18 and 20 hz. The particle size distribution of the ground material is quite stable before subsequent separation treatment, and the content of the ground material below 10 micrometers is less than 5 ten-thousandth.

Step 3), during cyclone separation, increasing centrifugal force and throwing most of fine dust out;

cyclone separation is a process of removing fine particles using centrifugal force. In order to obtain the best removal effect of micro powder particles, the opening and closing of the centrifugal fan opening are enlarged, the cyclone separation length-diameter ratio is reduced, the central fine powder passage pipe is enlarged, the outlet tightness of a finished product at the bottom is reduced, and the centrifugal force is increased. The inlet speed is increased from 2 m/s to 3 m/s, the fine powder extraction position is increased from 2 m/s to 2.5 m/s, and the superfine powder extraction rate is increased from 79% to 99%.

Step 4), screening out the remaining small part (almost none) of the fine dust of the leaking net by using an ultrasonic vibration sieve;

the ultrasonic vibration sieve has sieve pore size of 12 microns or more, and has main effects of quality assurance and inspection, if fine powder is sieved out from the sieved channel, the condition that the centrifugal force is not enough is indicated that some fishes are also leaked, and the centrifugal force needs to be continuously increased until no fine powder is sieved out from the channel.

And 5) detecting by using a laser particle size analyzer to ensure that the dust is really free.

Detecting by a laser particle size analyzer to obtain actually-measured particle size distribution, and if the content of particles with particle sizes smaller than 10 microns is higher than 0.01% (one ten thousandth of the lowest measured value), determining that the particles contain dust and are not qualified; if the content of the particles with the particle size of less than 10 microns is less than or equal to 0.01 percent (one ten thousandth of the lowest measured value), the dust-free glass is judged to be free and qualified.

Finally, it is also noted that the above-mentioned lists merely illustrate a few specific embodiments of the invention. It is obvious that the invention is not limited to the above embodiments, but that many variations are possible. All modifications which can be derived or suggested by a person skilled in the art from the disclosure of the present invention are to be considered within the scope of the invention.