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1.
The color paste is added to the paint, and the color floats on the surface.
Reasons: 1) The surface tension difference between the color paste and the paint is too large.
The paint generally uses anionic or ionic polyelectrolyte dispersant, and the color paste generally uses non-ionic or Part of the anionic dispersant is used together to make the surface of white pigment and colored pigment adsorb different wetting and dispersing agents, and have different surface tensions.
2) The compatibility of the color paste and the coating is not good.
The emulsifier outside the emulsion particles is not compatible with the surfactant outside the pigment and filler particles, which causes the flocculation of the pigment.
3) The hydrophilic and lipophilic balance value between the color paste and the paint does not match the lipophilic substance, the surface tension of the lipophilic end is small, and it is easier to float on the surface.
4) The influence of thickeners Some associative thickeners with strong pseudoplasticity have a great affinity with surfactants with larger HLB values, causing them to desorb on the surface of the pigment, causing aggregation and flocculation of the pigment, resulting in floating color Send flowers.
Solution: Choosing a suitable wetting and dispersing agent, adjusting the surface properties of the particles, and adjusting the balance of movement are the best methods to control the floating color.
If colored pigments flocculate, whiten, and pigments flocculate floating, wetting and dispersing agents can be used to relieve flocculation, improve the surface properties of particles, prevent or control floating.
In the process of controlling floating, several floating phenomena can be transformed into each other to control floating color.
If the color of the color paste is floating, it means that the HLB value of the coating is large and relatively hydrophilic.
The addition of lipophilic and low-polar additives during the preparation of the base paint reduces the HLB value of the coating; if the floating color is white, it means The HLB value of the coating is relatively small and relatively lipophilic.
The hydrophilic additives are added during the preparation of the base paint to increase the hydrophilicity of the coating.
In some systems, it can resist the floating color of the coating film.
Add an anionic wetting and dispersing agent to the finished paint to adsorb on the surface of carbon black or organic purple pigment particles to improve the surface properties of the pigment particles and enhance the polarity.
These non-polarity are weak.
The polar particles have the same polarity as the white particles, and have the same degree of adsorption and flocculation as the polymer, so they have the same movement ability during the drying of the coating film, and the floating color is controlled.
Use surfactants that strongly reduce the surface tension.
Silicone surfactants are commonly used to make them migrate to the surface during the drying process of the coating to form a single molecular film, balance the surface tension and control the blooming; but the floating color may still exist. Adding some additives that can produce a thixotropic structure, such as kaolin or silica, forms a network structure in the paint film to prevent separation of pigments, control pigment flocculation, sedimentation and flow of Benard's vortex, and reduce floating color The blooming phenomenon prevents floating or blooming.
2.
The reasons for the obvious roller marks in the wall paint on the wall: 1) The thickness is uneven during the painting operation 2) There is no wet connection in the construction 3) Compatibility problems 4) Insufficient additives in the latex paint 5) In the latex paint The amount of latex is not enough.
6) The wall is not completed at one time.
Solution: It is mainly to solve the compatibility problem.
1) Mechanical dispersion (paint) The color of the paint can be displayed when a certain mechanical force is dispersed.
2) Adding wetting agent (color paint) After adding wetting agent, the color becomes much darker, which means that the color difference in grinding becomes smaller and there is no obvious brush mark after brushing.
3) Adjust the paint formula (basic paint) and change the wetting, dispersing and thickening system of the paint to solve the compatibility problem of the paint and the color paste.
3.
After the rain, there are obvious rain marks on the surface of the colored paint.
Reasons: 1) The base paint is poor in water resistance (the emulsion is too hydrophilic, the wetting agent is too much or the amount of hydrophilic additives is too large) 2) The base material contains too much water or the environment Excessive humidity 3) Sealing primer, the effect is not achieved 4) The coating film is not completely dry, it will be washed away with water 5) Too much residual amount of additives in dark paint Preventive methods: 1) Use surfactants as little as possible, and use organic as much as possible Silicone, reducing moisture absorption.
2) Use fluorine-based modified resins or additives to enhance water repellency and stain resistance.
3) Use emulsion with good water resistance.
4) The surface is painted with varnish.
4.
After the rain, the color paint surface has obvious reasons for discoloration: 1) The surface dry time of the paint film construction is insufficient, and rainwater will be encountered less than 2 hours after construction.
2) The PVC concentration of the coating is too high, that is, the emulsion is too low or the filling amount is too high.
3) The water resistance of the paint film is extremely poor.
The solution: 1) Increase the content of the emulsion.
2) Choose emulsion with good water resistance.
5.
After a period of time, the wall is obviously faded (blooming).
Reasons: 1) The emulsion content of the paint is low.
2) The water resistance of the coating is not good.
3) Improper selection of colorants.
4) The dark color will become lighter if the paint film is chalked.
5) Color migration (migrating to the inside).
6) Conditions such as the sun exposure temperature of the construction project cause the drying rate to be poor.
7) The flatness is not enough, resulting in poor distant vision under the influence of gloss.
Solution: 1) Increase the emulsion content in the paint.
2) Choose color paste with good weather resistance.
3) Engineering condition control.
6.
The reason why the required color cannot be called: 1) The content of titanium dioxide is inappropriate (colors with poor hiding power cannot be displayed).
2) Improper selection of color paste (some colors cannot be replaced by other color pastes).
3) Color migration.
Solution: 1) Choose a coating with appropriate titanium dioxide content.
2) Choose color paste with good compatibility.
The color paste is added to the paint, and the color floats on the surface.
Reasons: 1) The surface tension difference between the color paste and the paint is too large.
The paint generally uses anionic or ionic polyelectrolyte dispersant, and the color paste generally uses non-ionic or Part of the anionic dispersant is used together to make the surface of white pigment and colored pigment adsorb different wetting and dispersing agents, and have different surface tensions.
2) The compatibility of the color paste and the coating is not good.
The emulsifier outside the emulsion particles is not compatible with the surfactant outside the pigment and filler particles, which causes the flocculation of the pigment.
3) The hydrophilic and lipophilic balance value between the color paste and the paint does not match the lipophilic substance, the surface tension of the lipophilic end is small, and it is easier to float on the surface.
4) The influence of thickeners Some associative thickeners with strong pseudoplasticity have a great affinity with surfactants with larger HLB values, causing them to desorb on the surface of the pigment, causing aggregation and flocculation of the pigment, resulting in floating color Send flowers.
Solution: Choosing a suitable wetting and dispersing agent, adjusting the surface properties of the particles, and adjusting the balance of movement are the best methods to control the floating color.
If colored pigments flocculate, whiten, and pigments flocculate floating, wetting and dispersing agents can be used to relieve flocculation, improve the surface properties of particles, prevent or control floating.
In the process of controlling floating, several floating phenomena can be transformed into each other to control floating color.
If the color of the color paste is floating, it means that the HLB value of the coating is large and relatively hydrophilic.
The addition of lipophilic and low-polar additives during the preparation of the base paint reduces the HLB value of the coating; if the floating color is white, it means The HLB value of the coating is relatively small and relatively lipophilic.
The hydrophilic additives are added during the preparation of the base paint to increase the hydrophilicity of the coating.
In some systems, it can resist the floating color of the coating film.
Add an anionic wetting and dispersing agent to the finished paint to adsorb on the surface of carbon black or organic purple pigment particles to improve the surface properties of the pigment particles and enhance the polarity.
These non-polarity are weak.
The polar particles have the same polarity as the white particles, and have the same degree of adsorption and flocculation as the polymer, so they have the same movement ability during the drying of the coating film, and the floating color is controlled.
Use surfactants that strongly reduce the surface tension.
Silicone surfactants are commonly used to make them migrate to the surface during the drying process of the coating to form a single molecular film, balance the surface tension and control the blooming; but the floating color may still exist. Adding some additives that can produce a thixotropic structure, such as kaolin or silica, forms a network structure in the paint film to prevent separation of pigments, control pigment flocculation, sedimentation and flow of Benard's vortex, and reduce floating color The blooming phenomenon prevents floating or blooming.
2.
The reasons for the obvious roller marks in the wall paint on the wall: 1) The thickness is uneven during the painting operation 2) There is no wet connection in the construction 3) Compatibility problems 4) Insufficient additives in the latex paint 5) In the latex paint The amount of latex is not enough.
6) The wall is not completed at one time.
Solution: It is mainly to solve the compatibility problem.
1) Mechanical dispersion (paint) The color of the paint can be displayed when a certain mechanical force is dispersed.
2) Adding wetting agent (color paint) After adding wetting agent, the color becomes much darker, which means that the color difference in grinding becomes smaller and there is no obvious brush mark after brushing.
3) Adjust the paint formula (basic paint) and change the wetting, dispersing and thickening system of the paint to solve the compatibility problem of the paint and the color paste.
3.
After the rain, there are obvious rain marks on the surface of the colored paint.
Reasons: 1) The base paint is poor in water resistance (the emulsion is too hydrophilic, the wetting agent is too much or the amount of hydrophilic additives is too large) 2) The base material contains too much water or the environment Excessive humidity 3) Sealing primer, the effect is not achieved 4) The coating film is not completely dry, it will be washed away with water 5) Too much residual amount of additives in dark paint Preventive methods: 1) Use surfactants as little as possible, and use organic as much as possible Silicone, reducing moisture absorption.
2) Use fluorine-based modified resins or additives to enhance water repellency and stain resistance.
3) Use emulsion with good water resistance.
4) The surface is painted with varnish.
4.
After the rain, the color paint surface has obvious reasons for discoloration: 1) The surface dry time of the paint film construction is insufficient, and rainwater will be encountered less than 2 hours after construction.
2) The PVC concentration of the coating is too high, that is, the emulsion is too low or the filling amount is too high.
3) The water resistance of the paint film is extremely poor.
The solution: 1) Increase the content of the emulsion.
2) Choose emulsion with good water resistance.
5.
After a period of time, the wall is obviously faded (blooming).
Reasons: 1) The emulsion content of the paint is low.
2) The water resistance of the coating is not good.
3) Improper selection of colorants.
4) The dark color will become lighter if the paint film is chalked.
5) Color migration (migrating to the inside).
6) Conditions such as the sun exposure temperature of the construction project cause the drying rate to be poor.
7) The flatness is not enough, resulting in poor distant vision under the influence of gloss.
Solution: 1) Increase the emulsion content in the paint.
2) Choose color paste with good weather resistance.
3) Engineering condition control.
6.
The reason why the required color cannot be called: 1) The content of titanium dioxide is inappropriate (colors with poor hiding power cannot be displayed).
2) Improper selection of color paste (some colors cannot be replaced by other color pastes).
3) Color migration.
Solution: 1) Choose a coating with appropriate titanium dioxide content.
2) Choose color paste with good compatibility.
