CN111560209A - Powder coating with skin feeling and visual angle color changing function and preparation method thereof - Google Patents

Abstract

The invention discloses a powder coating with skin feeling and color changing function along with visual angle and a preparation method thereof, wherein the formula comprises the following raw materials: base powder, composite metal powder, bonding auxiliary agent and powder flow auxiliary agent; wherein the amount of the composite metal powder accounts for 1-5% of the weight of the base powder; the dosage of the bonding auxiliary agent accounts for 0.2-0.5% of the weight of the base powder; the amount of the powder flow additive accounts for 0.1-0.15% of the weight of the base powder; the color-changing spray gun is not only suitable for spraying of metal base materials, but also can change color along with the change of visual angles like peacock feathers. In addition, the spraying factory can achieve the required effect only by implementing the spraying process of the common metal powder, and the method is simple to implement and low in implementation cost.

Description

Powder coating with skin feeling and visual angle color changing function and preparation method thereof

Technical Field

The invention relates to the technical field of powder coatings, in particular to a powder coating with skin feeling and color changing function along with visual angles and a preparation method thereof.

Background

The powder coating is a solid powdery synthetic resin coating which is composed of solid resin, pigment, filler, auxiliary agent and the like, and has four advantages of economy, environmental protection, high efficiency, excellent performance and the like in production and use.

With the continuous improvement of the requirements of people on decorative materials, the market has higher and higher requirements on the performance of the surface of a metal base material, particularly for the coating of workpieces needing to be in contact with human bodies. Users desire greater comfort and softness when a human body comes into contact with it.

However, the existing powder coating on the market has poor adhesion with metal base materials, is not suitable for use, is harsh to the touch of human bodies, and has monotonous and unchanged color.

Based on the demands of the market, the powder coating which can be suitable for spraying of metal base materials, has good touch feeling with a human body and can change colors is urgently needed to be developed.

Disclosure of Invention

In view of the above technical problems, the present invention has the following objects: a powder coating having skin feel and a function of changing color with viewing angle, which is applicable to spray coating of a metal substrate, and which can change color with change of viewing angle and has a skin-like touch, and a method for producing the same are provided.

The technical scheme adopted by the invention for solving the technical problems is as follows:

a powder coating with skin feeling and color changing function along with visual angle comprises the following formula raw materials: base powder, composite metal powder, bonding auxiliary agent and powder flow auxiliary agent; wherein the amount of the composite metal powder accounts for 1-5% of the weight of the base powder; the dosage of the bonding auxiliary agent accounts for 0.2-0.5% of the weight of the base powder; the amount of the powder flow additive accounts for 0.1-0.15% of the weight of the base powder;

the base powder is prepared from the following raw materials in parts by weight:

60-75 parts of saturated polyester;

4-6 parts of a curing agent;

0.8-1.2 parts of a universal leveling agent;

0.2-0.5 part of general brightening and hardening agent;

benzoin-0.3-0.5 parts;

5-8 parts of a weather-resistant matting agent;

1-35 parts of barium sulfate;

0.8-25 parts of pigment;

the composite metal powder is prepared from the following raw materials in parts by weight:

10-45 parts of single-coated aluminum silver powder D50 with the diameter of 13 mu m;

the single-coated aluminum silver powder D50 is 24 mu m-10-45 parts;

10-45 parts of color-changing pearl powder.

According to a further preferable technical scheme, the curing agent is a TGIC curing agent.

A preparation method of a powder coating with skin feeling and color changing function along with visual angle comprises the following steps:

s1, weighing the base powder, the composite metal powder, the bonding auxiliary agent and the powder flow auxiliary agent with required dosage; wherein the amount of the composite metal powder accounts for 1-5% of the weight of the base powder; the dosage of the bonding auxiliary agent accounts for 0.2-0.5% of the weight of the base powder; the amount of the powder flow additive accounts for 0.1-0.15% of the weight of the base powder;

s2, selecting different levels of bonding machines according to the single quantity, adding corresponding parts by weight of base powder according to the capacity of the bonding machines, and then adding the weighed bonding auxiliary agent;

s3, starting a bonding machine, and adding the weighed composite metal powder after the temperature in the bonding machine is raised to 45-50 ℃;

s4, after adding the composite metal powder, continuing bonding for 50-70 seconds, and extracting a proper amount of powder sample from a discharge hole of a bonding machine for inspection;

if the powder sample has the sign of agglomeration, directly carrying out the next step;

if the powder sample is in a loose state, continuously heating, and then checking until the powder sample has a sign of agglomeration;

s5, when the powder is checked to have the agglomeration sign, firstly preserving the heat for 200 seconds, then cooling to 35-45 ℃, then adding the weighed powder flowing agent, and rapidly stirring for 10-20 seconds;

s6, putting the stirred materials into a cooling pot, and cooling to 20-35 ℃;

s7, sieving the cooled material by a sieve of 100-120 meshes to obtain the powder coating with skin feeling and color changing function along with visual angle.

According to a further preferable technical scheme, the extraction amount of the powder sample is 800-1200 g.

According to a further preferable technical scheme, the agglomeration sign is that small lumps of 2-5 cm are observed visually and can be scattered after being kneaded by hand lightly.

Further preferably, when the powder sample is checked, if the powder sample is in a loose state, the temperature is continuously increased, then the powder sample is checked, the gradient of the continuous temperature increase is 1 ℃, and the temperature is kept for 1 minute after the temperature increase, and then the powder sample is sampled and checked.

Further preferably, after the powder flowing agent is added, the frequency of rapid stirring is 40-45 Hz.

Further preferably, the preparation method of the base powder comprises the following steps:

a. quantitatively weighing the following raw materials in parts by weight: 60-75 parts of saturated polyester, 4-6 parts of TGIC curing agent, 0.2-0.5 part of universal leveling agent, 0.2-0.5 part of universal brightening and hardening agent, 0.3-0.5 part of benzoin, 5-8 parts of weather-resistant flatting agent, 1-35 parts of barium sulfate and 0.8-25 parts of pigment;

b. premixing the weighed raw materials, and specifically comprising the following steps:

firstly, 1/2 saturated polyester is added into a stirring tank, then all other raw materials are added, and finally the rest 1/2 saturated polyester is added into the stirring tank;

c. stirring the premixed raw materials, and specifically comprising the following steps:

after the feeding is finished, firstly setting the stirring tank to stir at a low speed for 3 minutes, and then setting the stirring tank to stir at a high speed for 60 seconds; wherein the rotating speed frequency of the slow stirring is 20Hz, and the rotating speed frequency of the rapid stirring is 40 Hz;

d. putting the uniformly stirred mixed raw materials into a feeding hopper of an extruder, performing melt extrusion, and tabletting, cooling and crushing the extruded coating to obtain a sheet material;

e. grinding the crushed sheet materials in a grinding machine, and adjusting the main grinding speed and the auxiliary grinding speed to ensure that the particle size D50 is 32-42 mu m;

f. and screening the ground powder coating through a 200-mesh rotary screen to obtain the base powder.

According to a further preferable technical scheme, the extruder is a double-screw extruder, the melting temperature of the extruder is set in a three-section gradient mode, the temperature of the first gradient is set to be 95-100 ℃, the temperature of the second gradient is set to be 100-105 ℃, and the temperature of the third gradient is set to be 105-110 ℃.

According to a further preferable technical scheme, the extruder needs to be preheated to a set temperature before extrusion, and starts to extrude after being stabilized for 10 minutes.

According to a further preferred technical scheme, the composite metal powder is prepared by mixing the following raw materials in parts by weight:

10-45 parts of single-coated aluminum silver powder D50 with the diameter of 13 mu m;

the single-coated aluminum silver powder D50 is 24 mu m-10-45 parts;

10-45 parts of color-changing pearl powder.

The invention has the beneficial effects that: the powder coating disclosed by the invention not only can be suitable for spraying of a metal substrate, but also can change the color along with the change of visual angles like peacock feathers. In addition, the spraying factory can achieve the required effect only by implementing the spraying process of the common metal powder, and the method is simple to implement and low in implementation cost.

Detailed Description

The following specific production implementation process of the present invention is explained in detail with reference to specific examples:

example 1:

the specific production detection process of the invention is as follows:

respectively preparing base powder and composite metal powder according to the following raw material formula table;

base powder formula table:

the formula of the composite metal powder is as follows:

name of metal	Parts by weight
		Single-coated aluminum silver powder D50 ═ 13um	10
Single-coated aluminum silver powder D50 ═ 24um	10
		Color-changing pearl powder	10

The preparation method of the base powder comprises the following steps:

(1) weighing:

quantitatively weighing corresponding raw materials according to the formula table;

(2) mixing and stirring:

firstly, 1/2 saturated polyester is added into a stirring tank, then all other raw materials are added, and finally the rest 1/2 saturated polyester is added into the stirring tank;

after the feeding is finished, firstly setting the stirring tank to stir at a low speed for 3 minutes, and then setting the stirring tank to stir at a high speed for 60 seconds; wherein the rotating speed frequency of the slow stirring is 20Hz, and the rotating speed frequency of the rapid stirring is 40 Hz;

(3) melt extrusion

Adopting a double-screw extruder, setting the temperature of a first gradient of the melting temperature of the extruder to be 95 ℃, the temperature of a second gradient to be 100 ℃, and the temperature of a third gradient to be 105 ℃ (the temperature of each zone cannot be set to be too high or too low, the temperature can be coked during extrusion when being too high, and the temperature can not be melted when being too low), and stabilizing for 10 minutes after preheating to the set temperature;

putting the uniformly stirred mixed raw materials into a feeding hopper of a double-screw extruder, performing melt extrusion, and tabletting, cooling and crushing the extruded coating to obtain a sheet material;

(4) sampling detection

During the extrusion process, about 100 g of the middle part of the tablet is selected, ground by a small mill and sieved by a 200-mesh sieve.

Taking the undersize powder for the following detection: selecting a standard detection plate without oil, rust and other stains as a spraying substrate to carry out electrostatic spraying, wherein the spraying thickness is 60-80 um; then, the mixture is put into an oven at 200 ℃ for baking for 10 minutes, and after being taken out and naturally cooled, the color, luster, skin feel, impact and adhesive force are detected.

The color standard mainly comprises visual inspection and instrument detection, wherein the instrument detection requirement dE is less than 1, the single-color phase deviation is less than 0.5, the gloss requirement is 10-12% by using a 60-degree angle gloss instrument, the skin feel is judged by the feeling of lightly touching the coating film on the back of the hand, the impact strength qualified standard is that the positive impact is more than or equal to 50kg cm, the back impact is more than or equal to 30kg cm, and the adhesion force requirement is measured by a Baige method to reach 0 level.

And extruding according to the process after the indexes pass, and repeating the three steps of premixing, stirring and extruding after corresponding adjustment if the indexes do not pass through the process until the indexes are qualified.

(5) Grinding and screening

Grinding the crushed sheet materials in an ACM grinder, and adjusting the main grinding speed and the auxiliary grinding speed to ensure that the particle size D50 is 32-42 mu m; and screening the ground powder coating through a 200-mesh rotary screen to obtain the base powder. In addition, the sampling was performed every 200KG (10 boxes).

After the base powder and the composite metal powder are prepared, the powder coating with skin feeling and color changing function along with visual angle, which is required by the invention, is prepared, and the method comprises the following steps:

s1, weighing the base powder, the composite metal powder, the bonding auxiliary agent and the powder flow auxiliary agent with required dosage; wherein the amount of the composite metal powder accounts for 1% of the weight of the base powder; the dosage of the bonding auxiliary agent accounts for 0.2 percent of the weight of the base powder; the amount of the powder flow aid accounts for 0.1 percent of the weight of the base powder;

s2, selecting different levels of bonding machines according to the single quantity, adding corresponding parts by weight of base powder according to the capacity of the bonding machines, and then adding the weighed bonding auxiliary agent;

s3, starting a bonding machine, and adding the weighed composite metal powder after the temperature in the bonding machine is raised to 45 ℃;

s4, after adding the composite metal powder, continuing bonding for 50 seconds, and extracting 1000g of a proper amount of powder sample from a discharge hole of a bonding machine for inspection;

if the powder sample has the sign of agglomeration, directly carrying out the next step; wherein the agglomeration sign is that small lumps of 2-5 cm are observed visually and can be scattered after being slightly kneaded by hands,

if the powder sample is in a loose state, continuously heating, wherein the gradient of each continuous heating is 1 ℃, keeping for 1 minute after heating, and then sampling and checking until the powder sample has a sign of agglomeration;

s5, when the powder is checked to have the agglomeration sign, firstly preserving the heat for 200 seconds, then cooling to 35 ℃, then adding the weighed powder flowing agent, and rapidly stirring for 10 seconds, wherein the rapid stirring frequency is 40 Hz;

s6, putting the stirred materials into a cooling pot, and cooling to 20 ℃;

during specific large-scale production, sampling detection needs to be carried out from a cooling pot, and the specific detection process is as follows:

taking a proper amount of powder from a cooling pot, sieving the powder by a 120-mesh sieve, taking the sieved powder, and selecting a standard detection plate without oil, rust and other stains as a spraying substrate to carry out electrostatic spraying, wherein the spraying thickness is 60-80 mu m; and then, baking the mixture in an oven at 200 ℃ for 10 minutes, taking out the mixture for natural cooling, detecting the color, the gloss and the color change effect, wherein the color is determined visually, the gloss is detected by a 60-degree angle gloss instrument to be 10-12%, the color change effect is determined visually at different visual angles, the mixture is bound according to the metal proportion and the process after passing, if the mixture does not pass, the step is repeated after the second pot is correspondingly adjusted, and the mixture is mixed with the first pot until the mixture is qualified.

S7, sieving the cooled material with a 100-mesh sieve to obtain the powder coating with skin feeling and color changing function along with visual angle.

After the powder coating prepared by the method is cured at 200 ℃ for 10min, the powder coating conforms to GB/T5237.4-2017 part 4 of aluminum alloy building section: spray powder section bar standard.

Example 2:

the specific production detection process of the invention is as follows:

respectively preparing base powder and composite metal powder according to the following raw material formula table;

base powder formula table:

the formula of the composite metal powder is as follows:

name of metal	Parts by weight
		Single-coated aluminum silver powder D50 ═ 13um	25
Single-coated aluminum silver powder D50 ═ 24um	25
		Color-changing pearl powder	25

The preparation method of the base powder comprises the following steps:

(2) weighing:

quantitatively weighing corresponding raw materials according to the formula table;

(2) mixing and stirring:

firstly, 1/2 saturated polyester is added into a stirring tank, then all other raw materials are added, and finally the rest 1/2 saturated polyester is added into the stirring tank;

after the feeding is finished, firstly setting the stirring tank to stir at a low speed for 3 minutes, and then setting the stirring tank to stir at a high speed for 60 seconds; wherein the rotating speed frequency of the slow stirring is 20Hz, and the rotating speed frequency of the rapid stirring is 40 Hz;

(3) melt extrusion

A double-screw extruder is adopted, the temperature of a first gradient of the melting temperature of the extruder is set to be 95-100 ℃, the temperature of a second gradient is set to be 100-105 ℃, the temperature of a third gradient is set to be 105-110 ℃ (the temperature of each zone cannot be set to be too high or too low, the high temperature can be coked during extrusion, and the low temperature can not be melted), and the mixture is preheated to the set temperature and then is stabilized for 10 minutes;

putting the uniformly stirred mixed raw materials into a feeding hopper of a double-screw extruder, performing melt extrusion, and tabletting, cooling and crushing the extruded coating to obtain a sheet material;

(4) sampling detection

During the extrusion process, about 100 g of the middle part of the tablet is selected, ground by a small mill and sieved by a 200-mesh sieve.

Taking the undersize powder for the following detection: selecting a standard detection plate without oil, rust and other stains as a spraying substrate to carry out electrostatic spraying, wherein the spraying thickness is 60-80 um; then, the mixture is put into an oven at 200 ℃ for baking for 10 minutes, and after being taken out and naturally cooled, the color, luster, skin feel, impact and adhesive force are detected.

The color standard mainly comprises visual inspection and instrument detection, wherein the instrument detection requirement dE is less than 1, the single-color phase deviation is less than 0.5, the gloss requirement is 10-12% by using a 60-degree angle gloss instrument, the skin feel is judged by the feeling of lightly touching the coating film on the back of the hand, the impact strength qualified standard is that the positive impact is more than or equal to 50kg cm, the back impact is more than or equal to 30kg cm, and the adhesion force requirement is measured by a Baige method to reach 0 level.

And extruding according to the process after the indexes pass, and repeating the three steps of premixing, stirring and extruding after corresponding adjustment if the indexes do not pass through the process until the indexes are qualified.

(5) Grinding and screening

Grinding the crushed sheet materials in an ACM grinder, and adjusting the main grinding speed and the auxiliary grinding speed to ensure that the particle size D50 is 32-42 mu m; and screening the ground powder coating through a 200-mesh rotary screen to obtain the base powder. In addition, the sampling was performed every 200KG (10 boxes).

After the base powder and the composite metal powder are prepared, the powder coating with skin feeling and color changing function along with visual angle, which is required by the invention, is prepared, and the method comprises the following steps:

s1, weighing the base powder, the composite metal powder, the bonding auxiliary agent and the powder flow auxiliary agent with required dosage; wherein the amount of the composite metal powder accounts for 3% of the weight of the base powder; the dosage of the bonding auxiliary agent accounts for 0.35 percent of the weight of the base powder; the amount of the powder flow aid accounts for 0.12 percent of the weight of the base powder;

s2, selecting different levels of bonding machines according to the single quantity, adding corresponding parts by weight of base powder according to the capacity of the bonding machines, and then adding the weighed bonding auxiliary agent;

s3, starting a bonding machine, and adding the weighed composite metal powder after the temperature in the bonding machine is raised to 47 ℃;

s4, after adding the composite metal powder, continuing bonding for 60 seconds, and extracting 1000g of a proper amount of powder sample from a discharge hole of a bonding machine for inspection;

if the powder sample has the sign of agglomeration, directly carrying out the next step; wherein the agglomeration sign is that small lumps of 2-5 cm are observed visually and can be scattered after being slightly kneaded by hands,

if the powder sample is in a loose state, continuously heating, wherein the gradient of each continuous heating is 1 ℃, keeping for 1 minute after heating, and then sampling and checking until the powder sample has a sign of agglomeration;

s5, when the powder is checked to have the agglomeration sign, firstly preserving the heat for 200 seconds, then cooling to 40 ℃, then adding the weighed powder flowing agent, and rapidly stirring for 15 seconds, wherein the rapid stirring frequency is 43 Hz;

s6, putting the stirred materials into a cooling pot, and cooling to 28 ℃;

during specific large-scale production, sampling detection needs to be carried out from a cooling pot, and the specific detection process is as follows:

taking a proper amount of powder from a cooling pot, sieving the powder by a 120-mesh sieve, taking the sieved powder, and selecting a standard detection plate without oil, rust and other stains as a spraying substrate to carry out electrostatic spraying, wherein the spraying thickness is 60-80 mu m; and then, baking the mixture in an oven at 200 ℃ for 10 minutes, taking out the mixture for natural cooling, detecting the color, the gloss and the color change effect, wherein the color is determined visually, the gloss is detected by a 60-degree angle gloss instrument to be 10-12%, the color change effect is determined visually at different visual angles, the mixture is bound according to the metal proportion and the process after passing, if the mixture does not pass, the step is repeated after the second pot is correspondingly adjusted, and the mixture is mixed with the first pot until the mixture is qualified.

S7, sieving the cooled material with a 110-mesh sieve to obtain the powder coating with skin feeling and color changing function along with visual angle.

After the powder coating prepared by the method is cured at 200 ℃ for 10min, the powder coating conforms to GB/T5237.4-2017 part 4 of aluminum alloy building section: spray powder section bar standard.

Example 3

The specific production detection process of the invention is as follows:

respectively preparing base powder and composite metal powder according to the following raw material formula table;

base powder formula table:

the formula of the composite metal powder is as follows:

name of metal	Parts by weight
		Single-coated aluminum silver powder D50 ═ 13um	45
Single-coated aluminum silver powder D50 ═ 24um	45
		Color-changing pearl powder	45

The preparation method of the base powder comprises the following steps:

(3) weighing:

quantitatively weighing corresponding raw materials according to the formula table;

(2) mixing and stirring:

firstly, 1/2 saturated polyester is added into a stirring tank, then all other raw materials are added, and finally the rest 1/2 saturated polyester is added into the stirring tank;

after the feeding is finished, firstly setting the stirring tank to stir at a low speed for 3 minutes, and then setting the stirring tank to stir at a high speed for 60 seconds; wherein the rotating speed frequency of the slow stirring is 20Hz, and the rotating speed frequency of the rapid stirring is 40 Hz;

(3) melt extrusion

Adopting a double-screw extruder, setting the temperature of a first gradient of the melting temperature of the extruder to be 100 ℃, the temperature of a second gradient to be 105 ℃, and the temperature of a third gradient to be 110 ℃ (the temperature of each zone cannot be set to be too high or too low, the temperature can be coked during extrusion when being too high, and the temperature can not be melted when being too low), and stabilizing for 10 minutes after preheating to the set temperature;

putting the uniformly stirred mixed raw materials into a feeding hopper of a double-screw extruder, performing melt extrusion, and tabletting, cooling and crushing the extruded coating to obtain a sheet material;

(4) sampling detection

During the extrusion process, about 100 g of the middle part of the tablet is selected, ground by a small mill and sieved by a 200-mesh sieve.

Taking the undersize powder for the following detection: selecting a standard detection plate without oil, rust and other stains as a spraying substrate to carry out electrostatic spraying, wherein the spraying thickness is 60-80 um; then, the mixture is put into an oven at 200 ℃ for baking for 10 minutes, and after being taken out and naturally cooled, the color, luster, skin feel, impact and adhesive force are detected.

The color standard mainly comprises visual inspection and instrument detection, wherein the instrument detection requirement dE is less than 1, the single-color phase deviation is less than 0.5, the gloss requirement is 10-12% by using a 60-degree angle gloss instrument, the skin feel is judged by the feeling of lightly touching the coating film on the back of the hand, the impact strength qualified standard is that the positive impact is more than or equal to 50kg cm, the back impact is more than or equal to 30kg cm, and the adhesion force requirement is measured by a Baige method to reach 0 level.

And extruding according to the process after the indexes pass, and repeating the three steps of premixing, stirring and extruding after corresponding adjustment if the indexes do not pass through the process until the indexes are qualified.

(5) Grinding and screening

Grinding the crushed sheet materials in an ACM grinder, and adjusting the main grinding speed and the auxiliary grinding speed to ensure that the particle size D50 is 32-42 mu m; and screening the ground powder coating through a 200-mesh rotary screen to obtain the base powder. In addition, the sampling was performed every 200KG (10 boxes).

After the base powder and the composite metal powder are prepared, the powder coating with skin feeling and color changing function along with visual angle, which is required by the invention, is prepared, and the method comprises the following steps:

s1, weighing the base powder, the composite metal powder, the bonding auxiliary agent and the powder flow auxiliary agent with required dosage; wherein the amount of the composite metal powder accounts for 5% of the weight of the base powder; the dosage of the bonding auxiliary agent accounts for 0.5 percent of the weight of the base powder; the amount of the powder flow aid accounts for 0.15 percent of the weight of the base powder;

s2, selecting different levels of bonding machines according to the single quantity, adding corresponding parts by weight of base powder according to the capacity of the bonding machines, and then adding the weighed bonding auxiliary agent;

s3, starting a bonding machine, and adding the weighed composite metal powder after the temperature in the bonding machine is raised to 50 ℃;

s4, after adding the composite metal powder, continuing bonding for 70 seconds, and extracting 1000g of a proper amount of powder sample from a discharge hole of a bonding machine for inspection;

if the powder sample has the sign of agglomeration, directly carrying out the next step; wherein the agglomeration sign is that small lumps of 2-5 cm are observed visually and can be scattered after being slightly kneaded by hands,

if the powder sample is in a loose state, continuously heating, wherein the gradient of each continuous heating is 1 ℃, keeping for 1 minute after heating, and then sampling and checking until the powder sample has a sign of agglomeration;

s5, when the powder is checked to have the agglomeration sign, firstly preserving the heat for 200 seconds, then cooling to 45 ℃, then adding the weighed powder flowing agent, and rapidly stirring for 20 seconds, wherein the rapid stirring frequency is 45 Hz;

s6, putting the stirred materials into a cooling pot, and cooling to 35 ℃;

during specific large-scale production, sampling detection needs to be carried out from a cooling pot, and the specific detection process is as follows:

taking a proper amount of powder from a cooling pot, sieving the powder by a 120-mesh sieve, taking the sieved powder, and selecting a standard detection plate without oil, rust and other stains as a spraying substrate to carry out electrostatic spraying, wherein the spraying thickness is 60-80 mu m; and then, baking the mixture in an oven at 200 ℃ for 10 minutes, taking out the mixture for natural cooling, detecting the color, the gloss and the color change effect, wherein the color is determined visually, the gloss is detected by a 60-degree angle gloss instrument to be 10-12%, the color change effect is determined visually at different visual angles, the mixture is bound according to the metal proportion and the process after passing, if the mixture does not pass, the step is repeated after the second pot is correspondingly adjusted, and the mixture is mixed with the first pot until the mixture is qualified.

S7, sieving the cooled material with a 120-mesh sieve to obtain the powder coating with skin feeling and color changing function along with visual angle.

After the powder coating prepared by the method is cured at 200 ℃ for 10min, the powder coating conforms to GB/T5237.4-2017 part 4 of aluminum alloy building section: spray powder section bar standard.

The basic principles and the main features of the solution and the advantages of the solution have been shown and described above. It will be understood by those skilled in the art that the present solution is not limited to the embodiments described above, which are described in the specification and illustrated only to illustrate the principles of the solution, but that various changes and modifications may be made to the solution without departing from the spirit and scope of the solution, and these changes and modifications are intended to be within the scope of the claimed solution. The scope of the present solution is defined by the appended claims and equivalents thereof.

Claims (10)

1. The powder coating with skin feeling and color changing function along with visual angle is characterized by comprising the following formula raw materials: base powder, composite metal powder, bonding auxiliary agent and powder flow auxiliary agent; wherein the amount of the composite metal powder accounts for 1-5% of the weight of the base powder; the dosage of the bonding auxiliary agent accounts for 0.2-0.5% of the weight of the base powder; the amount of the powder flow additive accounts for 0.1-0.15% of the weight of the base powder;

the base powder is prepared from the following raw materials in parts by weight:

60-75 parts of saturated polyester;

4-6 parts of a curing agent;

0.8-1.2 parts of a universal leveling agent;

0.2-0.5 part of general brightening and hardening agent;

benzoin-0.3-0.5 parts;

5-8 parts of a weather-resistant matting agent;

1-35 parts of barium sulfate;

0.8-25 parts of pigment;

the composite metal powder is prepared from the following raw materials in parts by weight:

10-45 parts of single-coated aluminum silver powder D50 with the diameter of 13 mu m;

the single-coated aluminum silver powder D50 is 24 mu m-10-45 parts;

10-45 parts of color-changing pearl powder.

2. The powder coating having skin feel and color change with viewing angle of claim 1, wherein said curing agent is TGIC curing agent.

3. A preparation method of a powder coating with skin feeling and color changing function along with visual angle is characterized by comprising the following steps:

s1, weighing the base powder, the composite metal powder, the bonding auxiliary agent and the powder flow auxiliary agent with required dosage; wherein the amount of the composite metal powder accounts for 1-5% of the weight of the base powder; the dosage of the bonding auxiliary agent accounts for 0.2-0.5% of the weight of the base powder; the amount of the powder flow additive accounts for 0.1-0.15% of the weight of the base powder;

s2, selecting different levels of bonding machines according to the single quantity, adding corresponding parts by weight of base powder according to the capacity of the bonding machines, and then adding the weighed bonding auxiliary agent;

s3, starting a bonding machine, and adding the weighed composite metal powder after the temperature in the bonding machine is raised to 45-50 ℃;

s4, after adding the composite metal powder, continuing bonding for 50-70 seconds, and extracting a proper amount of powder sample from a discharge hole of a bonding machine for inspection;

if the powder sample has the sign of agglomeration, directly carrying out the next step;

if the powder sample is in a loose state, continuously heating, and then checking until the powder sample has a sign of agglomeration;

s5, when the powder is checked to have the agglomeration sign, firstly preserving the heat for 200 seconds, then cooling to 35-45 ℃, then adding the weighed powder flowing agent, and rapidly stirring for 10-20 seconds; the frequency of rapid stirring is 40-45 Hz;

s6, putting the stirred materials into a cooling pot, and cooling to 20-35 ℃;

s7, sieving the cooled material by a sieve of 100-120 meshes to obtain the powder coating with skin feeling and color changing function along with visual angle.

4. The method of claim 3, wherein the powder sample has an extraction amount of 800-1200 g.

5. The method of claim 3, wherein the signs of agglomeration are measured visually as small lumps of 2-5 cm and are measured as loose after being lightly kneaded with a hand.

6. The method of claim 3, wherein the powder sample is inspected, and when the powder sample is loose, the temperature is further increased, and then the inspection is performed, wherein the temperature is further increased at a gradient of 1 ℃, and the temperature is maintained for 1 minute after the temperature is increased, and then the sampling inspection is performed.

7. A process for preparing a powder coating having skin feel and color change with viewing angle as claimed in claim 3, wherein the base powder is prepared by:

a. quantitatively weighing the following raw materials in parts by weight: 60-75 parts of saturated polyester, 4-6 parts of TGIC curing agent, 0.2-0.5 part of universal leveling agent, 0.2-0.5 part of universal brightening and hardening agent, 0.3-0.5 part of benzoin, 5-8 parts of weather-resistant flatting agent, 1-35 parts of barium sulfate and 0.8-25 parts of pigment;

b. premixing the weighed raw materials, and specifically comprising the following steps:

firstly, 1/2 saturated polyester is added into a stirring tank, then all other raw materials are added, and finally the rest 1/2 saturated polyester is added into the stirring tank;

c. stirring the premixed raw materials, and specifically comprising the following steps:

after the feeding is finished, firstly setting the stirring tank to stir at a low speed for 3 minutes, and then setting the stirring tank to stir at a high speed for 60 seconds; wherein the rotating speed frequency of the slow stirring is 20Hz, and the rotating speed frequency of the rapid stirring is 40 Hz;

d. putting the uniformly stirred mixed raw materials into a feeding hopper of an extruder, performing melt extrusion, and tabletting, cooling and crushing the extruded coating to obtain a sheet material;

e. grinding the crushed sheet materials in a grinding machine, and adjusting the main grinding speed and the auxiliary grinding speed to ensure that the particle size D50 is 32-42 mu m;

f. and screening the ground powder coating through a 200-mesh rotary screen to obtain the base powder.

8. The method for preparing a powder coating with skin feeling and color change with visual angle of claim 7, wherein the extruder is a twin-screw extruder, and the melting temperature of the extruder is set in a three-stage gradient manner, and the temperature of the first gradient is set to 95-100 ℃, the temperature of the second gradient is set to 100-105 ℃, and the temperature of the third gradient is set to 105-110 ℃.

9. The method for preparing a powder coating with skin feeling and color changing with visual angle as claimed in claim 7, wherein the extruder is preheated to a set temperature before extrusion, and is stabilized for 10 minutes before the extrusion.

10. The preparation method of the powder coating with skin feeling and color changing function along with visual angle as claimed in claim 3, wherein the composite metal powder is prepared by mixing the following raw materials in parts by weight:

10-45 parts of single-coated aluminum silver powder D50 with the diameter of 13 mu m;

the single-coated aluminum silver powder D50 is 24 mu m-10-45 parts;

10-45 parts of color-changing pearl powder.