News Details
Water based epoxy resin coating USES crosslinking agent
2017-5-3 16:27:15
Water based epoxy resin coating USES crosslinking agent. Waterborne epoxy resin coating is a kind of emulsion paint, its mechanism of membrane with general polymer emulsion paint, such as acrylic emulsion film has the very big difference, at the same time and solvent epoxy coatings film is not entirely the same.
General polymer emulsion coating cross stitch is a physical process, the glass transition temperature of dispersed phase particles is low, in the structure of water evaporated to form close packing, condenses into membrane and under the effect of capillary pressure.
In solvent epoxy coatings system, epoxy resin and the crosslinking agent are in the form of molecules dissolved in organic solvent, the formation of the system is homogeneous, the crosslinking reaction between the molecules, thus crosslinking reaction more fully, the formation of the coating film is homogeneous. Water-based epoxy resin coating is a polyphase system, epoxy resin is dispersed in the water in the form of dispersive phase, and water-based epoxy solids are dissolved in water.
The mixture of two components is applied to the base material, and the water evaporates quickly under the appropriate temperature conditions. When most of the evaporation, epoxy resin latex particles contact each other, form a tightly packed structure, residual moisture and crosslinking agent molecules in epoxy resin dispersed phase particle clearance.
As the water evaporates further, the dispersed phase particles of the epoxy resin begin to form, forming a more compact hexagonal arrangement. At the same time, the crosslinking molecule diffuses into the interface of the dispersed phase particle of epoxy resin and its internal crosslinking reaction. Couplet film mechanism, this system can also be interpreted as waterborne epoxy resin by oil-in-water status to invert, and preparation process of epoxy resin emulsion by instead turn method just the opposite.
Assume that turn in the opposite in the preparation of waterborne epoxy resin emulsion the average particle size of dispersed phase particles of 0.5 microns, and set up its density is 1.16 g/mL, epoxy resin molecular weight is 1000, swelling is not considered in the water, can be calculated for each epoxy resin latex particles containing 4.6 x l07 molecule, so the crosslinking of waterborne epoxy resin system is by the crosslinking agent to epoxy resin is determined by the diffusion rate of the dispersed phase particles, which compared with solvent epoxy resin system got behind its hand in membrane process is more complicated.
Crosslinking agent molecules first and epoxy resin dispersed phase particle surface contact with crosslinking reaction, as the crosslinking reaction of epoxy resin molecular weight and glass transition temperature of the dispersed phase increase gradually, the crosslinking agent molecules to epoxy resin dispersed phase particles within the diffusion speed gradually slow down, which means that internal crosslinking reaction of epoxy resin dispersed phase particles less than its surface, internal crosslinking density is low.
Chinese name: Diethyl toluene diamine(DETDA)
Chinese alias: aryl, aryl diethyl - aryl - methyl-p-phenylenediamine
English name: Benzenediamine, ar, ar-diethyl-ar-methyl-English aliases:Diethyltoluenediamine; ar, ar-Diethyl-ar-methylbenzenediamine;Diethylmethylbenzenediamine;
CAS No. :68479-98-1
EINECS No. :270 -877-4
Molecular formula: C11H18N2
Molecular Weight: 178.28
Boiling point: 310 ℃
Refractive index: 1.581
Flash Point: > 140 ℃
Inchi: InChI = 1/C11H18N2/c1-4-8-6-7 (3) 10 (12) 11 (13) 9 (8) 5-2/h6H ,4-5,12-13H2 ,1-3H3 density : 1.022
Risk Codes: R10; R35
RIDADR: UN 3082
Safety instructions: S2; S26; S39; S61
Packing Group: III
Hazard Class: 6.1
At the same time, as the crosslinking reaction progresses, the particles of the dispersed phase of the epoxy resin gradually harden, and the particles are hard to interact with each other. It is difficult to form the coating of the homogeneous and complete crosslinking of epoxy resin coating.
Therefore, whether the crosslinking of water-based epoxy coatings is fully dependent on the following two factors.
(1) epoxy resin particle size of dispersed phase particles In waterborne epoxy crosslinking agent, under the condition of same ring oxygen resin dispersed phase particle size is small, concentrations of crosslinking agent on the surface of the particles is relatively moderate, slower surface crosslinking, the crosslinking agent molecules have enough time to spread to the whole epoxy resin dispersed phase particles, crosslinking completely, thus can form uniform, crosslinked coating completely.
Conversely, when the dispersed phase particle size is large, the surface of the particle has relatively high concentration of crosslinking agent, causing the surface to cross quickly. Epoxy resin as the crosslinking reaction of the apparent viscosity of dispersed phase particles increased, the glass transition temperature will also increase gradually, the crosslinking agent molecules to epoxy resin particle internal diffusion speed gradually slow, epoxy resin particles inside too late cross-linking incomplete crosslinking in the film.
(2) the epoxy crosslinking agent compatibility with epoxy resin Improve the epoxy crosslinking agent and compatibility of the epoxy resin, is conducive to stability of waterborne epoxy resin emulsion dispersed after system, and the better the compatibility of the two, epoxy crosslinking agent internal diffusion, the easier it is to the epoxy resin particles is advantageous to the crosslinking reaction.
Copyright: Zhang Jia Gang YaRui Chemical co.,Ltd
Diethyl toluene diamine(DETDA) http://www.yaruichem.com
General polymer emulsion coating cross stitch is a physical process, the glass transition temperature of dispersed phase particles is low, in the structure of water evaporated to form close packing, condenses into membrane and under the effect of capillary pressure.
In solvent epoxy coatings system, epoxy resin and the crosslinking agent are in the form of molecules dissolved in organic solvent, the formation of the system is homogeneous, the crosslinking reaction between the molecules, thus crosslinking reaction more fully, the formation of the coating film is homogeneous. Water-based epoxy resin coating is a polyphase system, epoxy resin is dispersed in the water in the form of dispersive phase, and water-based epoxy solids are dissolved in water.
The mixture of two components is applied to the base material, and the water evaporates quickly under the appropriate temperature conditions. When most of the evaporation, epoxy resin latex particles contact each other, form a tightly packed structure, residual moisture and crosslinking agent molecules in epoxy resin dispersed phase particle clearance.
As the water evaporates further, the dispersed phase particles of the epoxy resin begin to form, forming a more compact hexagonal arrangement. At the same time, the crosslinking molecule diffuses into the interface of the dispersed phase particle of epoxy resin and its internal crosslinking reaction. Couplet film mechanism, this system can also be interpreted as waterborne epoxy resin by oil-in-water status to invert, and preparation process of epoxy resin emulsion by instead turn method just the opposite.
Assume that turn in the opposite in the preparation of waterborne epoxy resin emulsion the average particle size of dispersed phase particles of 0.5 microns, and set up its density is 1.16 g/mL, epoxy resin molecular weight is 1000, swelling is not considered in the water, can be calculated for each epoxy resin latex particles containing 4.6 x l07 molecule, so the crosslinking of waterborne epoxy resin system is by the crosslinking agent to epoxy resin is determined by the diffusion rate of the dispersed phase particles, which compared with solvent epoxy resin system got behind its hand in membrane process is more complicated.
Crosslinking agent molecules first and epoxy resin dispersed phase particle surface contact with crosslinking reaction, as the crosslinking reaction of epoxy resin molecular weight and glass transition temperature of the dispersed phase increase gradually, the crosslinking agent molecules to epoxy resin dispersed phase particles within the diffusion speed gradually slow down, which means that internal crosslinking reaction of epoxy resin dispersed phase particles less than its surface, internal crosslinking density is low.
Chinese name: Diethyl toluene diamine(DETDA)
Chinese alias: aryl, aryl diethyl - aryl - methyl-p-phenylenediamine
English name: Benzenediamine, ar, ar-diethyl-ar-methyl-English aliases:Diethyltoluenediamine; ar, ar-Diethyl-ar-methylbenzenediamine;Diethylmethylbenzenediamine;
CAS No. :68479-98-1
EINECS No. :270 -877-4
Molecular formula: C11H18N2
Molecular Weight: 178.28
Boiling point: 310 ℃
Refractive index: 1.581
Flash Point: > 140 ℃
Inchi: InChI = 1/C11H18N2/c1-4-8-6-7 (3) 10 (12) 11 (13) 9 (8) 5-2/h6H ,4-5,12-13H2 ,1-3H3 density : 1.022
Risk Codes: R10; R35
RIDADR: UN 3082
Safety instructions: S2; S26; S39; S61
Packing Group: III
Hazard Class: 6.1
At the same time, as the crosslinking reaction progresses, the particles of the dispersed phase of the epoxy resin gradually harden, and the particles are hard to interact with each other. It is difficult to form the coating of the homogeneous and complete crosslinking of epoxy resin coating.
Therefore, whether the crosslinking of water-based epoxy coatings is fully dependent on the following two factors.
(1) epoxy resin particle size of dispersed phase particles In waterborne epoxy crosslinking agent, under the condition of same ring oxygen resin dispersed phase particle size is small, concentrations of crosslinking agent on the surface of the particles is relatively moderate, slower surface crosslinking, the crosslinking agent molecules have enough time to spread to the whole epoxy resin dispersed phase particles, crosslinking completely, thus can form uniform, crosslinked coating completely.
Conversely, when the dispersed phase particle size is large, the surface of the particle has relatively high concentration of crosslinking agent, causing the surface to cross quickly. Epoxy resin as the crosslinking reaction of the apparent viscosity of dispersed phase particles increased, the glass transition temperature will also increase gradually, the crosslinking agent molecules to epoxy resin particle internal diffusion speed gradually slow, epoxy resin particles inside too late cross-linking incomplete crosslinking in the film.
(2) the epoxy crosslinking agent compatibility with epoxy resin Improve the epoxy crosslinking agent and compatibility of the epoxy resin, is conducive to stability of waterborne epoxy resin emulsion dispersed after system, and the better the compatibility of the two, epoxy crosslinking agent internal diffusion, the easier it is to the epoxy resin particles is advantageous to the crosslinking reaction.
Copyright: Zhang Jia Gang YaRui Chemical co.,Ltd
Diethyl toluene diamine(DETDA) http://www.yaruichem.com
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