News Details
Crosslinking of paint crosslinking agent
2017-6-2 16:11:15
Crosslinking of paint crosslinking agent,Size directly affects the performance of the coating. The experimental method of crosslinking is the method of gelling, the potassium permanganate and the film performance test.
The alkali resistance of the coating reflects the crosslinking degree of the coating. An excess of 5 to 10 percent of crosslinking agents, and an increase in the alkalinity of the coating. Extending the baking time, the crosslinking density of the coating increased and the alkali resistance of the coating was obviously improved. When the baking time is too long, the coating's resistance to alkalinity declines slowly. The crosslinking density of the coating after the forced drying is superior to that of natural drying; After the preparation of coating, the curing time (within 30min), the coating's alkali resistance is improved slightly.
Different crosslinking agents have an effect on the alkali resistance of the coating. The crosslinking agent of the trimer is superior to biurea, and HDI crosslinking agent is slightly superior to IPDI crosslinking agent.
After the preparation of the coating, the time (30min) of the curing time (30min), the alkali resistance of the coating is improved slightly. The aged is too long and the performance is slightly lower.
The effect of film thickness on the alkali resistance of film. After the coating is made up, different film thickness is sprayed. After drying, it is alkaline (strengthening to 84h). The resistance of the coating to the thickness of the film decreases with the thickness of the membrane, which may be caused by the increase of the thickness of the membrane and the difficulty of the solvent in the lower layer.
The effect of additives on the alkali resistance of the coating. After adding different dosage of dry agent varnish and drying, the addition of dry agent to the coating is very small.
If the cross-linked polymer thickener, after alkali soluble polymer molecular chain can in solution to form a three-dimensional network structure, at the same time there are hydrophobic groups, the association is equal to the establishment of physical crosslinking between different polymer chains. This increases the viscosity of the thickening agent and improves its ability to resist shear. But if too much crosslinker w (DAP), is shown in figure 2 and figure 3, the light transmittance of the thickener alkali solution and viscosity were decreased, the thickener emulsion particles has not completely dissolved, will not be in solution to form a three-dimensional network structure.
Chinese name: Diethyl toluene diamine(DETDA)
Diethyltoluenediamine Raw material ：
TDA industrial, Sichuan production
Ethylene (Et) polymer grade, Shanghai production
TEA industrial imports
A reagent grade additives
This suggests that the chemical crosslinking agent DAP for around 0.1% of the mass of monomer, which just slightly crosslinked polymer of the thickener will improve the thickening efficiency and the effect of shear resistance. Excessive crosslinking agent can interfere with the alkali soluble of thickening agent, reducing the thickening effect significantly.
With MAA, EA and BEM as monomer to emulsification process of semi-continuous emulsion copolymerization, crosslinking agent (changes in the mass fraction of monomer, with a series of stable type association thickener emulsion.
The conversion rate of monomer in all polymerization was over 98%. Relative to the unused thickener emulsion crosslinking agent, add a small amount of DAP, made the latex particle size smaller but then latex particle size larger with the increase of mass fraction of DAP to continue;
When w (DAP) = 0.1% of the thickening agent, the transmittance and viscosity of the polymer were rapidly rising when the pH was 6.8, and at the pH value of 8.1. Since then, the pH value has been raised, the transmittance of the sample is basically constant, and its viscosity is slowly declining.
The thickening effect and shear performance can be improved when w (DAP) = 0.1% in the thickening agent polymer. When w (DAP) = 0.5 percent, the increase in the crosslinking degree of the polymer weakens the alkali solubility of the emulsion, and the thickening effect of the thickener is reduced.
Linseed oil and diethanolamine best proportion for Moore, TDI and HDI best mole ratio is 0.7, the total hydroxy and total different cyano optimum molar ratio is 1.1 ~ 1.1. Choose CH3ONa for resin synthesis catalyst, the dosage of 0.4%, the synthesis temperature is 130 ~ 140 ℃, resin acid value control in 30 ~ 50 mgkoh/g, neutralizing agent triethylamine, its dosage in final finishing system is limited in the pH = 8.5 ~ 9.5.
Copyright: Zhang Jia Gang YaRui Chemical co.,Ltd
Diethyl toluene diamine(DETDA) http://www.yaruichem.com
The alkali resistance of the coating reflects the crosslinking degree of the coating. An excess of 5 to 10 percent of crosslinking agents, and an increase in the alkalinity of the coating. Extending the baking time, the crosslinking density of the coating increased and the alkali resistance of the coating was obviously improved. When the baking time is too long, the coating's resistance to alkalinity declines slowly. The crosslinking density of the coating after the forced drying is superior to that of natural drying; After the preparation of coating, the curing time (within 30min), the coating's alkali resistance is improved slightly.
Different crosslinking agents have an effect on the alkali resistance of the coating. The crosslinking agent of the trimer is superior to biurea, and HDI crosslinking agent is slightly superior to IPDI crosslinking agent.
After the preparation of the coating, the time (30min) of the curing time (30min), the alkali resistance of the coating is improved slightly. The aged is too long and the performance is slightly lower.
The effect of film thickness on the alkali resistance of film. After the coating is made up, different film thickness is sprayed. After drying, it is alkaline (strengthening to 84h). The resistance of the coating to the thickness of the film decreases with the thickness of the membrane, which may be caused by the increase of the thickness of the membrane and the difficulty of the solvent in the lower layer.
The effect of additives on the alkali resistance of the coating. After adding different dosage of dry agent varnish and drying, the addition of dry agent to the coating is very small.
If the cross-linked polymer thickener, after alkali soluble polymer molecular chain can in solution to form a three-dimensional network structure, at the same time there are hydrophobic groups, the association is equal to the establishment of physical crosslinking between different polymer chains. This increases the viscosity of the thickening agent and improves its ability to resist shear. But if too much crosslinker w (DAP), is shown in figure 2 and figure 3, the light transmittance of the thickener alkali solution and viscosity were decreased, the thickener emulsion particles has not completely dissolved, will not be in solution to form a three-dimensional network structure.
Chinese name: Diethyl toluene diamine(DETDA)
Diethyltoluenediamine Raw material ：
TDA industrial, Sichuan production
Ethylene (Et) polymer grade, Shanghai production
TEA industrial imports
A reagent grade additives
This suggests that the chemical crosslinking agent DAP for around 0.1% of the mass of monomer, which just slightly crosslinked polymer of the thickener will improve the thickening efficiency and the effect of shear resistance. Excessive crosslinking agent can interfere with the alkali soluble of thickening agent, reducing the thickening effect significantly.
With MAA, EA and BEM as monomer to emulsification process of semi-continuous emulsion copolymerization, crosslinking agent (changes in the mass fraction of monomer, with a series of stable type association thickener emulsion.
The conversion rate of monomer in all polymerization was over 98%. Relative to the unused thickener emulsion crosslinking agent, add a small amount of DAP, made the latex particle size smaller but then latex particle size larger with the increase of mass fraction of DAP to continue;
When w (DAP) = 0.1% of the thickening agent, the transmittance and viscosity of the polymer were rapidly rising when the pH was 6.8, and at the pH value of 8.1. Since then, the pH value has been raised, the transmittance of the sample is basically constant, and its viscosity is slowly declining.
The thickening effect and shear performance can be improved when w (DAP) = 0.1% in the thickening agent polymer. When w (DAP) = 0.5 percent, the increase in the crosslinking degree of the polymer weakens the alkali solubility of the emulsion, and the thickening effect of the thickener is reduced.
Linseed oil and diethanolamine best proportion for Moore, TDI and HDI best mole ratio is 0.7, the total hydroxy and total different cyano optimum molar ratio is 1.1 ~ 1.1. Choose CH3ONa for resin synthesis catalyst, the dosage of 0.4%, the synthesis temperature is 130 ~ 140 ℃, resin acid value control in 30 ~ 50 mgkoh/g, neutralizing agent triethylamine, its dosage in final finishing system is limited in the pH = 8.5 ~ 9.5.
Copyright: Zhang Jia Gang YaRui Chemical co.,Ltd
Diethyl toluene diamine(DETDA) http://www.yaruichem.com
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