How to solve the problems in paint storage and construction?
With the reform of China’s housing system, the market of architectural coatings has developed rapidly, and some foreign companies have continuously launched various corresponding emulsions and additives, and the technical level of emulsion paints has been improving rapidly. For example, the scrub resistance of paint, leveling greatly improved; many companies produce latex paint can not float in one to two years; emergence of engineering paint, matte paint, high-gloss paint, silk paint, semi-gloss paint, stone paint, relief paint and many other varieties. However, in the face of quality problems in the process of storage and application of latex paint, manufacturers are often at their wits’ end, and it is proved that these problems can be solved and avoided by certain processes and formulations.
Technical problems occurring in the storage process and the solution
Coalescence and viscosity rise in the process of storage
(1) The possible reason is that the dispersant or wetting agent is not enough, or use some dispersant which is easy to decompose, such as sodium tripolyphosphate, potassium salt, these salts are easy to decompose in the storage process, causing the re-flocculation of pigment. Of course, when choosing dispersant, different types and quantities of dispersant should be used to avoid the failure of dispersant or the decrease of efficiency.
(2) Improper choice of color and filler, reactive color and filler, such as zinc oxide or filled titanium dioxide. In principle, such colors and fillers should not be used, and in case such substances exist, some special surfactant systems should be applied.
(3) Unstable pH value can also cause such problems. We should strengthen the control of buffer solution, control the amount of strong alkaline pigments, and use some thickeners with large pH range instead.
(4) Excessive organic solvents, such as film-forming additives or ethylene and propylene glycol are too much. Should reduce the amount of organic solvents, choose some high film-forming efficiency of additives.
Viscosity drop in the process of storage
(1) The thickener is degraded by bacteria or biological enzymes, some thickeners such as HEC are nutrients for bacteria, if there are bacteria decomposing the thickener, the viscosity drops. Therefore, it is necessary to improve the preservative condition or not to use HEC thickening system.
(2) pH value drifts away from the optimal working range of thickeners. Some alkali-swelling thickeners, such as ASE series, are more sensitive to pH, the best pH range between 9 and 10, such as the choice of ammonia to adjust the pH value, because the ammonia is easy to volatilize, resulting in a drop in pH, the efficiency of the thickener is reduced. Therefore, choose AMP-95 organic alkali as pH adjuster or use pH change less sensitive thickener.
Freeze-thaw instability
(1) The amount of film-forming additives is too high. Reduce the amount of film-forming additives by using efficient film-forming additives such as PPH or emulsions with lower Tg.
(2) The amount of antifreeze agent is not enough. The amount of diol should be increased.
(3) Unsuitable surfactant system. Few people pay attention to this cause. If freezing and thawing produce flocculation, increase the amount of surfactant; if freezing and thawing produce agglomeration, or viscosity rise, we should increase the amount of surfactant and diol, or increase the amount of protective gel, or increase the amount of all three at the same time.
Color change
The possible reasons for the color change during storage are:
(1) Improper selection or inappropriate quantity of surfactant; or incorrect type and dosage of dispersant. Dispersant replacement and change of dosage should be considered first. Generally, the emulsifier comes from the emulsion, you can also change the emulsifier or replace the emulsion.
(2) The pH value affects the effect of the thickener and the pigment flocculation, you can use the thickener which is not sensitive to pH value or increase the thickener.
(3) If the paint changes under the temperature and atmosphere, the formulation should be determined under the standard temperature and atmospheric pressure.
Problems in the application process and countermeasures
Fish eye and shrinkage
(1) The addition method of defoamer is not correct, some defoamers need to be added at the grinding stage, or diluted.
(2) The type of defoamer is not correct, for some silicone defoamer is not “safe”, need to be used with caution.
(3) The efficiency of the wetting agent is not enough, especially in the old wall, this problem is particularly so. The type of wetting agent should be improved.
(4) The oleophilic component is not compatible with the system, or the oleophilic component is not sufficiently emulsified. Mainly refers to antifreeze and film-forming additives. Attention should be paid to the addition of such substances to prevent incomplete emulsification.
(5) The emulsion paint is applied to the contaminated surface, such as the surface of oil, or the surface containing silicon. The surface should be treated, such as sanding, etc.
Those problems in the storage and construction of paints in the network information
Uneven color on closed surface and unsealed surface
(1) If the color is lighter on the unsealed surface than on the sealed surface, more film-forming auxiliaries are needed, or film-forming auxiliaries with higher film-forming efficiency should be used, and if the phenomenon is the opposite, the treatment method should be the opposite.
(2) improper selection of thickening agent, should be replaced by thickening agent.
Poor color spreading when blending
(1) The type and amount of surfactant and dispersant of the system is not appropriate, should choose the correct emulsifier or dispersant.
(2) There is low gelatinization value of hydroxypropyl methyl cellulose when the paint is warmed up, should be replaced with high gelatinization value of hydroxypropyl methyl cellulose.
Uneven luster
(1) The structure of the substrate is very uneven, so the substrate should be closed, such as using a closed primer to treat the substrate.
(2) There are very small bubbles in the paint, which will affect the local gloss. The defoamer should be improved or the leveling should be enhanced.
(3) Inappropriate filling system, mainly refers to the process of painting or rolling, the filling material with matting effect can not have orientation, in general, two or more kinds of filling material should be used.
(4) insufficient film-forming additives, or film formation at low temperatures, or dry too fast, should be changed according to the specific circumstances.
(5) incorrect thickener, especially when different kinds of thickeners are used in combination, more such situations will occur. Should change the thickener, or carefully choose the thickener with, such as ASE-type thickener will matte, but polyurethane thickener will increase the light, etc.
Bad wet abrasion resistance
1、Bad paint film formation, mainly because the type and amount of film-forming additives are not correct.
2, excessive water-absorbent color, filler, change the color, filler, such as titanium dioxide or filler with surface treatment, such as heavy calcium carbonate, barite, etc.
3、The presence of excessive surfactant will make the paint film very sensitive to water, so the correct surfactant should be selected or reduced.
4、Bad adhesion to the substrate, the surface should be treated. Incorrect use of film-forming additives or plasticizers, should follow the guidance of the emulsion supplier.
Bad covering power
1. The amount of pigment is too small, and the amount of pigment should be increased.
2. Titanium dioxide flocculates, increase the amount of surfactant or dispersant. The amount of diol should be increased, or suitable surfactant should be chosen.
3. Some components react with the anionic dispersant. The drift of pH value has an effect on the alkali-sensitive thickener. Suitable thickening agent or non-volatile pH adjuster should be used.
Poor paint film penetration
1、The main problem is film-forming additives.
2、There is a porous surface. The surface should be treated.
There are pinholes in the paint film after drying
(1) There is excessive defoamer in the paint film.
(2) Gas is released by the reaction during the storage process. It may be caused by the reaction of carbonate of filler with weak acid.
(3) The paint is applied to the surface of too many holes, and when the paint is applied, the gas inside the holes penetrates externally.
Bad adhesion
(1) If the paint is used on a surface that is over-powdered, apply a strong penetrating primer with small particle size emulsion for pretreatment.
(2) If the paint is used for old wall and lack of adhesion, the surface should be eradicated and pretreated.
ink raw materials : UV Photoinitiator Same series products
| Product name | CAS NO. | Chemical name |
| lcnacure® TPO | 75980-60-8 | Diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide |
| lcnacure® TPO-L | 84434-11-7 | Ethyl (2,4,6-trimethylbenzoyl) phenylphosphinate |
| lcnacure® 819/920 | 162881-26-7 | Phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide |
| lcnacure® 819 DW | 162881-26-7 | Irgacure 819 DW |
| lcnacure® ITX | 5495-84-1 | 2-Isopropylthioxanthone |
| lcnacure® DETX | 82799-44-8 | 2,4-Diethyl-9H-thioxanthen-9-one |
| lcnacure® BDK/651 | 24650-42-8 | 2,2-Dimethoxy-2-phenylacetophenone |
| lcnacure® 907 | 71868-10-5 | 2-Methyl-4′-(methylthio)-2-morpholinopropiophenone |
| lcnacure® 184 | 947-19-3 | 1-Hydroxycyclohexyl phenyl ketone |
| lcnacure® MBF | 15206-55-0 | Methyl benzoylformate |
| lcnacure® 150 | 163702-01-0 | Benzene, (1-methylethenyl)-, homopolymer,ar-(2-hydroxy-2-methyl-1-oxopropyl) derivs |
| lcnacure® 160 | 71868-15-0 | Difunctional alpha hydroxy ketone |
| lcnacure® 1173 | 7473-98-5 | 2-Hydroxy-2-methylpropiophenone |
| lcnacure® EMK | 90-93-7 | 4,4′-Bis(diethylamino) benzophenone |
| lcnacure® PBZ | 2128-93-0 | 4-Benzoylbiphenyl |
| lcnacure® OMBB/MBB | 606-28-0 | Methyl 2-benzoylbenzoate |
| lcnacure® 784/FMT | 125051-32-3 | BIS(2,6-DIFLUORO-3-(1-HYDROPYRROL-1-YL)PHENYL)TITANOCENE |
| lcnacure® BP | 119-61-9 | Benzophenone |
| lcnacure® 754 | 211510-16-6 | Benzeneacetic acid, alpha-oxo-, Oxydi-2,1-ethanediyl ester |
| lcnacure® CBP | 134-85-0 | 4-Chlorobenzophenone |
| lcnacure® MBP | 134-84-9 | 4-Methylbenzophenone |
| lcnacure® EHA | 21245-02-3 | 2-Ethylhexyl 4-dimethylaminobenzoate |
| lcnacure® DMB | 2208-05-1 | 2-(Dimethylamino)ethyl benzoate |
| lcnacure® EDB | 10287-53-3 | Ethyl 4-dimethylaminobenzoate |
| lcnacure® 250 | 344562-80-7 | (4-Methylphenyl) [4-(2-methylpropyl)phenyl] iodoniumhexafluorophosphate |
| lcnacure® 369 | 119313-12-1 | 2-Benzyl-2-(dimethylamino)-4′-morpholinobutyrophenone |
| lcnacure® 379 | 119344-86-4 | 1-Butanone, 2-(dimethylamino)-2-(4-methylphenyl)methyl-1-4-(4-morpholinyl)phenyl- |
| lcnacure® 938 | 61358-25-6 | Bis(4-tert-butylphenyl)iodonium hexafluorophosphate |
| lcnacure® 6992 MX | 75482-18-7 & 74227-35-3 | Cationic Photoinitiator UVI-6992 |
| lcnacure® 6992 | 68156-13-8 | Diphenyl(4-phenylthio)phenylsufonium hexafluorophosphate |
| lcnacure® 6993-S | 71449-78-0 & 89452-37-9 | Mixed type triarylsulfonium hexafluoroantimonate salts |
| lcnacure® 6993-P | 71449-78-0 | 4-Thiophenyl phenyl diphenyl sulfonium hexafluoroantimonate |
| lcnacure® 1206 | Photoinitiator APi-1206 |
UV ink raw materials : UV Monomer Same series products
| ACMO | 4-acryloylmorpholine | 5117-12-4 |
| ADAMA | 1-Adamantyl Methacrylate | 16887-36-8 |
| DCPEOA | Dicyclopentenyloxyethyl Acrylate | 65983-31-5 |
| DI-TMPTA | DI(TRIMETHYLOLPROPANE) TETRAACRYLATE | 94108-97-1 |
| DPGDA | Dipropylene Glycol Dienoate | 57472-68-1 |
| DPHA | Dipentaerythritol hexaacrylate | 29570-58-9 |
| ECPMA | 1-Ethylcyclopentyl Methacrylate | 266308-58-1 |
| EO10-BPADA | (10) ethoxylated bisphenol A diacrylate | 64401-02-1 |
| EO3-TMPTA | Ethoxylated trimethylolpropane triacrylate | 28961-43-5 |
| EO4-BPADA | (4) ethoxylated bisphenol A diacrylate | 64401-02-1 |
| EOEOEA | 2-(2-Ethoxyethoxy)ethyl acrylate | 7328-17-8 |
| GPTA ( G3POTA ) | GLYCERYL PROPOXY TRIACRYLATE | 52408-84-1 |
| HDDA | Hexamethylene diacrylate | 13048-33-4 |
| HEMA | 2-hydroxyethyl methacrylate | 868-77-9 |
| HPMA | 2-Hydroxypropyl methacrylate | 27813-02-1 |
| IBOA | Isobornyl acrylate | 5888-33-5 |
| IBOMA | Isobornyl methacrylate | 7534-94-3 |
| IDA | Isodecyl acrylate | 1330-61-6 |
| IPAMA | 2-isopropyl-2-adamantyl methacrylate | 297156-50-4 |
| LMA | Dodecyl 2-methylacrylate | 142-90-5 |
| NP-4EA | (4) ethoxylated nonylphenol | 2156-97-0 |
| NPGDA | Neopentyl glycol diacrylate | 2223-82-7 |
| PDDA | Phthalate diethylene glycol diacrylate | |
| PEGDA | Polyethylene Glycol Diacrylate | 26570-48-9 |
| PEGDMA | Poly(ethylene glycol) dimethacrylate | 25852-47-5 |
| PETA | PETA Monomer | 3524-68-3 |
| PHEA | 2-PHENOXYETHYL ACRYLATE | 48145-04-6 |
| PO2-NPGDA | NEOPENTYL GLYCOL PROPOXYLATE DIACRYLATE | 84170-74-1 |
| TEGDMA | Triethylene glycol dimethacrylate | 109-16-0 |
| THFA | Tetrahydrofurfuryl acrylate | 2399-48-6 |
| THFMA | Tetrahydrofurfuryl methacrylate | 2455-24-5 |
| TMPTA | Trimethylolpropane triacrylate | 15625-89-5 |
| TMPTMA | Trimethylolpropane trimethacrylate | 3290-92-4 |
| TPGDA | Tripropylene glycol diacrylate | 42978-66-5 |