CN110845941A - TGIC-substituted low-toxicity powder coating and preparation method thereof - Google Patents

Abstract

The invention relates to a TGIC-substituted low-toxicity powder coating and a preparation method thereof, the curing of the powder coating is closely related to the effective components of a coloring pigment and a surfactant of dodecyl benzene sulfonic acid, the effective components of the coloring pigment comprise a compound A and/or a compound B, both the compound A and the compound B comprise two oxazoline structures, can be combined with polyester resin, acid anhydride, epoxy resin, phenolic resin, phenols and the like to form a coating system with quick curing performance, and the compound A and the compound B are both high-temperature-resistant nitrogen-containing heterocyclic compounds, can enhance the physical and mechanical properties of smearing, and the compound with an oxazole ring has biological activity, the epoxy resin powder coating can be used as a substrate coloring pigment of the powder coating and can also be used as a curing agent to prepare an epoxy resin powder coating with good leveling property, excellent chemical resistance, scratch resistance and high mechanical property; in addition, it has excellent storage stability, color retention and weather resistance.

Description

A kind of substitute TGIC low toxicity powder coating and preparation method thereof

technical field

The invention relates to the field of powder coatings, in particular to a low-toxicity powder coating that replaces TGIC and a preparation method thereof.

Background technique

TGIC scientific name is tris(2,3-propylene oxide)-s-triazine-2,4,6(1H,3H,5H)trione, chemical name is triglycidyl isocyanurate, its relative molecular mass It is small and has 3 reactive groups, so it has a high crosslinking density when used as a curing agent for carboxylic polyester resins; secondly, the rigid urea ring structure on the molecular skeleton of TGIC increases the hardness of the cured coating film. , It has the characteristics of thermal and light stability and excellent weather resistance, good compatibility with polyester resin, and good mechanical and electrical properties of the cured product. Therefore, it is widely used in the coating field as a curing agent.

However, the biological toxicity of TGIC has always been a concern for the public. The European Union designated TGIC as a highly toxic drug in 1998. Therefore, it is necessary to develop a low-toxicity powder coating that can replace TGIC. This powder coating does not need to use TGIC as a curing agent. Stability, low biological toxicity, can effectively improve the safety performance of coatings.

SUMMARY OF THE INVENTION

The present invention provides an alternative TGIC low-toxicity powder coating and a preparation method thereof, so as to solve the problem of the biological toxicity of TGIC in the above content.

In order to reach the above-mentioned purpose, the technical scheme of the present invention is specifically realized in this way:

R：烃基A low-toxicity powder coating that replaces TGIC, by weight percentage, comprising: 15-30 parts of phenolic epoxy resin; 20-35 parts of epoxy resin; 3-10 parts of seagull stone powder; 5-25 parts of coloring pigment; 1-8 parts Parts of fumed silica; 0.1-3 parts of defoamer; 0.5-5 parts of dodecylbenzene sulfonic acid; 0.1-5 parts of coalescing agent; 5-30 parts of extender pigment; 1-5 parts of polypropylene adhesive An appropriate amount of PH regulator; wherein, the colored pigment includes at least one of compound A and compound B, and the chemical structural formula of compound A is shown in formula I:

R: Hydrocarbyl

The chemical structural formula of compound B is shown in formula II:

Preferably, the defoamer is at least one of modified polysiloxane, benzophenone, and polypropylene composite micropowder wax.

Preferably, the film-forming aid is amide-modified polyethylene wax, low molecular weight polyethylene, and silicone powder mixed in a ratio of 1:2:1.

Preferably, the extender pigment is at least one of silica sol, light calcium carbonate and wollastonite.

Preferably, in the color pigment, the weight percentage of the compound A and/or the compound B is 10%-45%, and the rest is toner.

Preferably, the toner is at least one of four color pigments of yellow, magenta, cyan and black.

Preferably, the compound A is 8,18-dichloro-5,15-diethyl-diindole(3,2-b:3',2'-m)triphenyldioxine or 8,18 -Dichloro-5,15-dimethyl-diindole(3,2-b:3',2'-m)triphenyldioxazine.

Preferably, the low-toxicity powder coating that replaces TGIC further comprises 0.5-5 parts of phthalic acid dihydrazide.

It can be understood that, if no curing agent is added in the present invention, the curing of the entire powder coating is closely related to the active ingredient of the coloring pigment and the surfactant dodecylbenzenesulfonic acid, and the active ingredient of the coloring pigment in this application includes Compound A and / or compound B, both compound A and compound B contain two oxazoline structures, which can form a coating system with fast curing properties with polyester resin, acid anhydride, epoxy resin, phenolic resin, phenol, etc., and compound A , Compound B are high temperature-resistant nitrogen-containing heterocyclic compounds, which can enhance the physical and mechanical properties of smearing. The compound with oxazole ring has biological activity, and can be used not only as a base coloring pigment for powder coatings in this application, but also as a curing agent. The epoxy resin powder coating with good leveling, excellent chemical resistance, scratch resistance and high mechanical properties is formulated; in addition, it has excellent storage stability, color retention and excellent weather resistance.

In addition, dodecylbenzene sulfonic acid can be used as both a curing catalyst and a surfactant in the coating system to improve the grinding efficiency, avoid the formation of skinning, and eliminate foam during the coating process. Prevent floating color, flower and shrinkage; in the process of coating, it can improve the adhesion and make the coating anti-mildew, anti-fouling and anti-static.

In the second aspect, the present invention also provides a kind of preparation method of the described alternative TGIC low toxicity powder coating, comprising the following steps:

Step S1: add the colored pigments to the ball mill, add 50-70 steel balls with a diameter of 6-8mm per 1kg, and 0.1-0.3kg anhydrous calcium chloride, and at a temperature of 65 ℃～90 ℃ (preferably Under the condition of 20℃), ball mill for 8h, then add dilute hydrochloric acid to boil for 3-4h, separate the dilute acid, filter, add water, wash, and dry;

Step S2: add the coloring pigment purified in step S1 into a high-speed mixer, add extender pigment and polypropylene adhesive, and start stirring after sealing. 15mins;

Step S3: heating the mixture obtained in step S2 to 120-150° C., adding defoamer, phenolic epoxy resin, epoxy resin, seagull stone powder, fumed silica, dodecylbenzenesulfonic acid, and film-forming aid in sequence. agent, stir evenly;

Step S3: adjusting the pH of the mixture obtained in step S2 to 6.8-7.1 with a pH regulator;

Step S4: Melting, kneading, extruding, cooling, tableting, and then pulverizing, classifying, and sieving through a pulverizer to become a finished product with a particle size of 200 meshes.

R：烃基The preparation method of the substitute TGIC low-toxicity powder coating obtained according to the above steps, by weight percentage, comprises: 15-30 parts of phenolic epoxy resin; 20-35 parts of epoxy resin; 3-10 parts of seagull stone powder; 5-25 parts of Color pigment; 1-8 parts of fumed silica; 0.1-3 parts of defoamer; 0.5-5 parts of dodecylbenzene sulfonic acid; 0.1-5 parts of coalescing agent; 5-30 parts of extender pigment; 1- 5 parts of polypropylene adhesive; an appropriate amount of PH regulator; wherein, the colored pigment comprises at least one of compound A and compound B, and the chemical structural formula of compound A is shown in formula I:

R: Hydrocarbyl

The chemical structural formula of compound B is shown in formula II:

Preferably, the defoamer is at least one of modified polysiloxane, benzophenone, and polypropylene composite micropowder wax.

Further preferably, the defoaming agent is benzophenone and polypropylene composite micropowder wax mixed at a ratio of 3:1.

Preferably, the film-forming aid is amide-modified polyethylene wax, low molecular weight polyethylene, and silicone powder mixed at a ratio of 1:2:1.

Preferably, the extender pigment is at least one of silica sol, light calcium carbonate, and wollastonite.

Further preferably, the extender pigment is a mixture of silica sol, light calcium carbonate and wollastonite in a ratio of 2:3:1.

Preferably, in the color pigment, the weight percentage of the compound A and/or the compound B is 10%-45%, and the rest is toner.

Preferably, the toner is at least one of four color pigments of yellow, magenta, cyan and black.

Preferably, the compound A is 8,18-dichloro-5,15-diethyl-diindole(3,2-b:3',2'-m)triphenyldioxine or 8,18 -Dichloro-5,15-dimethyl-diindole(3,2-b:3',2'-m)triphenyldioxazine.

Further preferably, 0.5-5 parts of phthalic acid dihydrazide is also added in step S3.

The beneficial effects of the present invention are:

(1) Compared with the formulation of the existing powder coating, the curing and coloring of the present invention adopts at least one of the compound A and the compound B in the coloring pigment, and when in use, the coloring example of the powder coating is very high, It has excellent heat resistance and light fastness. Even in the case of very low concentration, the heat resistance can be above 200 ℃, and the solvent resistance is good. Under the action of dodecylbenzenesulfonic acid, it can be used as a curing agent. The epoxy resin powder coating has excellent chemical resistance, scratch resistance and mechanical properties, as well as excellent storage stability, color retention and excellent weather resistance.

(2) In the present invention, phthalic acid dihydrazide can also be added, which can be used as a latent curing agent for epoxy resins, and a powder coating prepared by using epoxy resin/phthalic acid dihydrazide as a binder system The coating film has excellent flexibility, water resistance, weather resistance, corrosion resistance, insulation and decoration.

(3) The composition of the powder coating of the present invention is simple, the production cost of the powder coating can be reduced, and the powder coating with low toxicity, high efficiency and good performance can be produced, which can replace the application of TGIC in the powder coating.

(4) The seagull stone powder is added in the present invention, which can make the coating have the function of continuously releasing negative ions, can reduce environmental pollution, and is environmentally friendly, especially suitable for residential buildings, commercial buildings, public buildings and other occasions, and has broad application prospects.

Description of drawings

Fig. 1 is the color difference change of the coating of the powder coating corresponding to the test group of Example 1 and the control group under different baking temperatures;

Fig. 2 is the change of gloss retention rate of the coatings of the powder coatings corresponding to the test group of Example 1 and the control group at different baking temperatures;

Fig. 3 is the color difference change of the coating of the powder paint corresponding to the test group of Example 1 and the control group at different low temperatures;

Fig. 4 is the change of gloss retention rate of the coatings of powder coatings corresponding to the test group and the control group in Example 1 at different low temperatures;

Fig. 5 is the color difference change of the coating of the powder paint corresponding to the test group of Example 1 and the control group under different aging time;

Fig. 6 is the change of gloss retention rate of the coatings of the powder coatings corresponding to the test group and the control group in Example 1 under different aging times;

Fig. 7 is the color difference change of the coating of the powder paint corresponding to the test group of Example 1 and the control group under different boiling times;

Fig. 8 is the change of gloss retention rate of the coatings of the powder coatings corresponding to the test group and the control group in Example 1 under different boiling times;

Fig. 9 is the coating curing curve diagram of the powder coatings corresponding to the test group of Example 1 and the control group;

Figure 10 is the color difference change of the coatings of Example 2 powder coatings A, B, C and TGIC powder coatings (KH-R1003A2) under different aging times;

Figure 11 shows the change of gloss retention rate of the coatings of Example 2 powder coatings A, B, C and TGIC powder coatings (KH-R1003A2) under different aging times;

Figure 12 is the color difference change of the coatings of Example 2 powder coatings A, B, C and TGIC powder coatings (KH-R1003A2) under different boiling times;

Figure 13 is the change of gloss retention rate of the coatings of Example 2 powder coatings A, B, C and TGIC powder coatings (KH-R1003A2) under different boiling times;

Figure 14 is a graph of curing curves for the coatings of Example 2 powder coatings A, B, C and TGIC powder coatings (KH-R1003A2).

Detailed ways

The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

Example 1

(1) a kind of preparation method of described substitute TGIC low toxicity powder coating, comprises the steps:

Step S1: add the coloring pigments into the ball mill, add 65 steel balls with a diameter of 7 mm and 0.2 kg of anhydrous calcium chloride per 1 kg, and at a temperature of 80 ° C, ball mill for 8 hours, and then add dilute hydrochloric acid. Boil for 3.5h, separate the dilute acid, filter, add water, wash, and dry; wherein, the compound A is 8,18-dichloro-5,15-diethyl-diindole (3,2-b:3 ',2'-m) Triphenyldioxazine (A1) or 8,18-dichloro-5,15-dimethyl-diindole (3,2-b:3',2'-m)tris Benzodioxazine (A2); the compound B is 2,6-dibenzamide-3,7-diethoxy-9,10-diacetylaminotriphenyldioxazine;

Step S2: add the coloring pigment purified in step S1 into a high-speed mixer, add extender pigment and polypropylene adhesive, and turn on stirring after sealing, control the rotation speed at 1500 rpm, stir at a temperature of 60°C, and stir for 15 mins; wherein, the extender pigment is silica sol;

Step S3: heating the mixture obtained in step S2 to 135°C, adding defoamer, phenolic epoxy resin, epoxy resin, seagull stone powder, fumed silica, dodecylbenzenesulfonic acid, and film-forming aid in sequence, Stir well; wherein, the defoaming agent is benzophenone and polypropylene composite micropowder wax mixed at a ratio of 3:1; the film-forming aid is an amide-modified polyethylene wax, low molecular weight polyethylene, and silicone powder at a ratio of 1 : 2:1 mix;

Step S3: using a pH regulator to adjust the pH of the mixture obtained in step S2 to 6.9; wherein the pH regulator is sodium hydroxide;

Step S4: Melting, kneading, extruding, cooling, tableting, and then pulverizing, classifying, and sieving through a pulverizer to become a finished product with a particle size of 200 meshes.

The content of each component in the powder coating is shown in Table 1.

Table 1 Contents of components in substitute TGIC low toxicity powder coating

(2) Performance test

The commercially available TGIC powder coating (KH-R1003A2) was used as the control group, and the powder coatings of the above components 1-8 were used as the test group to conduct high temperature test, aging test, low temperature test, boiling test, toxicity test, skin test Irritation test, isothermal curing test, the color difference and gloss change of each powder coating coating under each environment are measured (the gloss of the coating is carried out according to the provisions of GB/T 9754, and the incident angle of 60° is used; according to GB/T 11186.2 and 11186.3).

①High temperature test

Select 108 metal plates of 5cm × 5cm and divide them into 9 groups on average. The powder coatings corresponding to the control group and the test group were sprayed evenly on the metal plates of each group, and each group was divided into 6 groups. A metal plate is a small group, and the metal plates of each group are placed in an oven and heated at 50°C, 100°C, 150°C, 200°C, 250°C, and 300°C for 15 hours, and the color difference and gloss of the coating are tested.

②Low temperature test

Select 108 metal plates of 5cm × 5cm and divide them into 9 groups on average. The powder coatings corresponding to the control group and the test group were sprayed evenly on the metal plates of each group, and each group was divided into 6 groups. A piece of metal plate is a small group, the metal plate of each group is placed in a freezer and cooled for 30 days at 10°C, 5°C, 0°C, -5°C, -10°C, -15°C, and the color difference of the coating is tested. and gloss.

③Aging test

The powder coatings of the control group and the test group were sprayed on a metal plate of 5 cm × 5 cm, respectively, and placed in the test box to be irradiated with a UVA-340 fluorescent ultraviolet lamp for 1 month. The test conditions were irradiance 0.88W/m2, 40 Illumination at ℃ for 12h, condensation at 0℃ for 12h, repeated illumination and condensation. After the experiment, the color difference and gloss of the coating surface were tested.

④Boil test

Select 108 metal plates of 5cm × 5cm and divide them into 9 groups on average. The powder coatings corresponding to the control group and the test group were sprayed evenly on the metal plates of each group, and each group was divided into 6 groups. A metal plate is a small group, and the metal plates of each group are placed in a sterilized pressure cooker for boiling, the water is deionized water, and the temperature is 100°C. After boiling for 5.5 hours, dry the surface of the metal plate and test the color difference and gloss.

⑤ Toxicology test

90 healthy mice weighing 30-50g, half male and half male, were selected and divided into 9 groups. The powder coatings of 8 groups of the experimental group and 1 group of the control group were diluted, 5g of powder coating was dissolved in each liter of water, and divided into 3 groups within 24 hours. The mice were fed for 1 month, and the survival rate of the mice was observed.

⑥Skin irritation test

Select 90 people from 8-15 years old, 16-35 years old, 36-55 years old, and 56-70 years old. People in each age group are divided into 9 groups, half male and female, 8 groups of experimental group and 1 The powder coating of the control group was mixed with water and then smeared on the inner arm of the human body, and the skin was observed for red spots, itching, tingling, etc.

⑦Isothermal curing test

A differential scanning calorimeter (DSC) was used to perform an isothermal curing test on the powder coating, and the test conditions were: nitrogen as protective gas, flow rate 50 mL/min; heating rate 25 °C/min, when rapidly warming to 25 °C, hold for 20min.

(3) Test results

①High temperature test: The high temperature resistance test results of powder coatings are shown in Figure 1 and Figure 2. Figure 1 shows the color difference changes of the powder coatings corresponding to the test group and the control group at different baking temperatures, and Figure 2 shows the test group Changes in gloss retention of the powder coatings corresponding to the control group at different baking temperatures, in which the test groups 1-8 correspond to the alternative TGIC low-toxicity powder coatings with different component contents in Table 1, and the control group corresponds to the commercially available powder coatings TGIC powder coating (KH-R1003A2). The results show that with the increase of the baking temperature, the color difference of the coatings of the test group and the control group gradually increases, and the change range of the color difference of the powder coatings of the control group 1-8 is smaller than that of the control group. During the baking process, the coating of the control group is at 50℃-150℃. The heat will gradually reduce the stability of the coating surface and the gloss retention rate will decrease slightly. Between 150℃-250℃, the heat will gradually dissolve the coating. , the gloss retention rate decreased sharply, and then the gloss retention rate dropped sharply again at 250 °C, which caused the secondary melting of the main coating at 250 °C, resulting in severe orange peel on the coated surface; while the test group 1 The gloss retention of the coating of -8 remained unchanged or slightly decreased under the test conditions, mainly due to the symmetry and planarity of the molecular structure of compound A and compound B, which made them quite stable, combined with epoxy resin, resistant to The heat temperature is above 250℃, the tinting strength is very high, and it has excellent heat resistance and light fastness. Comparing the coatings of the control group and the test groups 1-8 at different temperatures, it can be seen that the color retention and gloss retention of the test groups 1-8 are better than those of the control group.

②Low temperature test

The low temperature resistance test results of powder coatings are shown in Figure 3 and Figure 4. Figure 3 shows the color difference changes of the powder coatings corresponding to the test group and the control group at different low temperatures, and Figure 4 shows the powder coatings corresponding to the test group and the control group. Changes in gloss retention of coatings at different low temperatures, in which the test groups 1-8 correspond to the alternative TGIC low-toxicity powder coatings with different component contents in Table 1, and the control group corresponds to the commercially available TGIC powder coatings (KH-R1003A2) . The results show that with the decrease of temperature, the color difference and gloss retention of the coatings in the test group and the control group are relatively constant, and the color difference is maintained within 1 color difference value, and the low temperature resistance is excellent.

③Aging test

The aging resistance test results of powder coatings are shown in Figures 5 and 6. Figure 5 shows the color difference changes of the powder coatings corresponding to the test group and the control group under the same aging conditions and different aging times, and Figure 6 shows the test group. The gloss retention of the coatings of the powder coatings corresponding to the control group under the same aging conditions and different aging times changes. The test results of the coatings of the control group and the test group under different aging times can be seen that with aging With the increase of time, the color difference of the coating in the control group is gradually increasing, and the gloss retention rate is gradually decreasing. , in the same aging time, the change of the color difference of the coating of the control group is greater than that of the test group 1-8, and after 10 days of aging time, the gloss retention of the test group 1-8 is higher than that of the control group The gloss retention rate of the coating, that is, the coating of the powder coating of the present invention is better than the coating of the control group in terms of gloss retention and color retention, that is, the weather resistance is stronger.

④Boil test

The boiling test results of powder coatings are shown in Figure 7 and Figure 8. Figure 7 shows the color difference changes of the powder coatings corresponding to the test group and the control group under different boiling times, and Figure 8 shows the corresponding test group and control group. The gloss retention of the powder coating coating under different boiling times changes, as can be seen from Figure 7 and Figure 8, with the increase of the boiling time, the color difference of the coatings of the test groups 1-8 and the control group is increase, the gloss retention rate is decreasing; among them, the chromatic aberration change of the coatings of test group 3 and test group 7 in the initial stage is greater than that of the control group, but the color difference change of the subsequent coatings is slowed down, lower than that of the control group. The color difference of the coating changes, and the gloss retention of the test groups 1-8 is higher than that of the control group. It can be seen that the water resistance of the test groups 1-8 of the present application is better than that of the control group.

⑤ Toxicology test

The toxicological test results of powder coatings containing different component concentrations showed that: after continuous observation for 1 month, in the experimental group 1-8, none of the mice died, and no abnormal symptoms were found; in the control group, 2 mice died, Some have symptoms such as anorexia and apathy. The test results show that the toxicity of the powder coating in the present application is lower than that of the control group.

⑥Skin irritation test

The skin irritation test effects of different age groups are shown in Table 2. Compared with the TGIC powder coatings (KH-R1003A2) of the control group, the powder coatings of the test groups 1-8 are irritating to the skin. Less sex, less damage to human skin.

Table 2 The skin irritation test effect of different powder coatings

⑦Isothermal curing test

Referring to Figure 9, the time for the coating of the control group to reach complete curing during the isothermal curing process is 604s. Among the test groups 1-8, the curing time of the test group 5 is the fastest, and it takes 640s for complete curing, which means that the control group has the fastest curing time. The powder coating has a faster curing reaction rate and a higher degree of reaction, which is due to the fact that the control group contains a large amount of curing accelerator that can accelerate the reaction between polyester and TGIC, while the curing accelerator in this application consists of the surfactant dodecylbenzenesulfonic acid. The acid is completed, but overall, the reaction degree of the control group and polyester is not much different from that of the test group 5, which has little effect on the difference in the comprehensive performance of the coating. At the same temperature, the reaction rates of the other test groups are slower than those of the control group. The reaction rate, but still meet the normal use of powder coatings.

Example 2

In order to further illustrate the beneficial effects of the present invention, steps S1 to S4 of Example 1 are repeated, and 0.5-5 parts of phthalic acid dihydrazide is added in step S3 to obtain powder coating A, powder coating B, and powder coating C, Among them, each component and its weight percentage are shown in Table 3.

Figure 3 Components and their contents in powder coatings

According to the performance test ③-⑦ of Example 1, carry out aging test, boiling test, toxicity test, skin irritation test, isothermal curing test, and measure the color difference and gloss change of the coating of each powder coating under each environment .

test results

(1) The aging resistance test results of powder coatings are shown in Figure 10 and Figure 11. Figure 10 shows that the coatings of powder coatings A, B, C and TGIC powder coatings (KH-R1003A2) have different aging times under the same aging conditions. Figure 10 shows the change in gloss retention of powder coatings A, B, C and TGIC powder coatings (KH-R1003A2) under the same aging conditions and different aging times. It can be seen that powder coating A Compared with TGIC powder coating (KH-R1003A2), the gloss retention and color retention of , B and C are enhanced. Although the color difference increases with time, the growth trend is slow, the aging resistance is enhanced, and the weather resistance is improved. it is good.

(2) The boiling test results of powder coatings are shown in Figure 12 and Figure 13. As the boiling time increases, the coatings of powder coatings A, B, C and TGIC powder coatings (KH-R1003A2) increase with the boiling time. With the increase of time, the color difference increases and the gloss retention rate decreases, but the water resistance of powder coatings A, B and C is better than that of the control group.

(3) Toxicological test results of powder coatings A, B, C and TGIC powder coatings (KH-R1003A2) showed that after continuous observation for 1 month, it was found that none of the mice fed with diluted powder coatings A, B and C were found. No abnormal symptoms were found; 3 mice died of the diluted TGIC powder coating (KH-R1003A2), and some of them showed symptoms such as anorexia and lethargy. The test results show that the toxicity of powder coatings A, B and C in this application is lower than that of TGIC powder coatings (KH-R1003A2).

(4) The skin irritation test effect of different age groups is shown in Table 4. Compared with the TGIC powder coating (KH-R1003A2) of the control group, the powder coatings A, B, and C have the same effect on the skin. Less irritating, less damage to human skin.

Table 4 The skin irritation test effect of powder coatings A, B, C and TGIC powder coatings (KH-R1003A2)

(5) Referring to Figure 14, the coating of TGIC powder coating (KH-R1003A2) reaches complete curing time in the isothermal curing process for 599s, and powder coating C, powder coating A and powder coating B reach complete curing during the isothermal curing process. The curing time of powder coating C and powder coating A is higher than that of TGIC powder coating (KH-R1003A2), and the curing efficiency of powder coating B is the same as that of TGIC powder coating (KH-R1003A2). The curing efficiency is close, so adding phthalate dihydrazide to powder coatings can improve the curing efficiency of powder coatings.

Claims (10)

1. an alternative TGIC low toxicity powder coating is characterized in that, by weight percentage, comprising: 15-30 parts of novolac epoxy resins; 20-35 parts of epoxy resins; 3-10 parts of seagull stone powder; 5-25 parts of Color pigment; 1-8 parts of fumed silica; 0.1-3 parts of defoamer; 0.5-5 parts of dodecylbenzene sulfonic acid; 0.1-5 parts of coalescing agent; 5-30 parts of extender pigment; 1- 5 parts of polypropylene adhesive; an appropriate amount of PH regulator; wherein, the colored pigment comprises at least one of compound A and compound B, and the chemical structural formula of compound A is shown in formula I:

R: Hydrocarbyl The chemical structural formula of compound B is shown in formula II: 2. a kind of substitute TGIC low toxicity powder coating according to claim 1 is characterized in that: described defoamer is at least one in modified polysiloxane, benzophenone, polypropylene composite micropowder wax . 3. a kind of substitute TGIC low toxicity powder coating according to claim 1, is characterized in that: described film-forming aid is polyethylene wax of amide modification, low molecular weight polyethylene, organosilicon powder by 1:2: 1 mix. 4. a kind of substitute TGIC low toxicity powder coating as claimed in claim 1 is characterized in that: described extender pigment is at least one in silica sol, light calcium carbonate, wollastonite. 5. a kind of substitute TGIC low toxicity powder coating as claimed in claim 1 is characterized in that: in described colored pigment, the weight percent of described compound A and/or compound B is 10%-45%, The rest are toners. 6. A kind of substitute TGIC low toxicity powder coating as claimed in claim 5 is characterized in that: described toner is at least one of yellow, magenta, cyan, black four-color color pigments. 7. a kind of substitute TGIC low toxicity powder coating as claimed in claim 1 is characterized in that: described compound A is 8,18-dichloro-5,15-diethyl-diindole (3, 2-b:3',2'-m) Triphenyldioxazine or 8,18-dichloro-5,15-dimethyl-diindole(3,2-b:3',2'-m ) Triphenyldioxazine. 8. a kind of substitute TGIC low toxicity powder coating as claimed in claim 1 is characterized in that: also comprises 0.5-5 part of phthalic acid dihydrazide. 9. according to the preparation method of the described replacement TGIC low toxicity powder coating of any one of claim 1-8, it is characterized in that: comprise the steps: Step S1: add the coloring pigments to the ball mill, add 50-70 steel balls with a diameter of 6-8mm per 1kg, and 0.1-0.3kg anhydrous calcium chloride, and the temperature is 65 ℃～90 ℃ condition Then, ball mill for 8h, add dilute hydrochloric acid and boil for 3-4h, separate the dilute acid, filter, add water, wash, and dry; Step S2: add the coloring pigment purified in step S1 into a high-speed mixer, add extender pigment and polypropylene adhesive, and start stirring after sealing. 15mins; Step S3: heating the mixture obtained in step S2 to 120-150° C., adding defoamer, phenolic epoxy resin, epoxy resin, seagull stone powder, fumed silica, dodecylbenzenesulfonic acid, and film-forming aid in sequence. agent, stir evenly; Step S3: adjusting the pH of the mixture obtained in step S2 to 6.8-7.1 with a pH regulator; Step S4: Melting, kneading, extruding, cooling, tableting, and then pulverizing, classifying, and sieving through a pulverizer to become a finished product with a particle size of 200 meshes. 10. A method for preparing a TGIC low toxicity powder coating according to claim 9, characterized in that: in step S3, 0.5-5 parts of phthalic acid dihydrazide is also added.

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