How to solve the problems in paint storage and construction?

February 22, 2023
February 22, 2023 Longchang Chemical

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
Sinocure® TPO 75980-60-8 Diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide
Sinocure® TPO-L 84434-11-7 Ethyl (2,4,6-trimethylbenzoyl) phenylphosphinate
Sinocure® 819/920 162881-26-7 Phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide
Sinocure® 819 DW 162881-26-7 Irgacure 819 DW
Sinocure® ITX 5495-84-1 2-Isopropylthioxanthone
Sinocure® DETX 82799-44-8 2,4-Diethyl-9H-thioxanthen-9-one
Sinocure® BDK/651 24650-42-8 2,2-Dimethoxy-2-phenylacetophenone
Sinocure® 907 71868-10-5 2-Methyl-4′-(methylthio)-2-morpholinopropiophenone
Sinocure® 184 947-19-3 1-Hydroxycyclohexyl phenyl ketone
Sinocure® MBF 15206-55-0 Methyl benzoylformate
Sinocure® 150 163702-01-0 Benzene, (1-methylethenyl)-, homopolymer,ar-(2-hydroxy-2-methyl-1-oxopropyl) derivs
Sinocure® 160 71868-15-0 Difunctional alpha hydroxy ketone
Sinocure® 1173 7473-98-5 2-Hydroxy-2-methylpropiophenone
Sinocure® EMK 90-93-7 4,4′-Bis(diethylamino) benzophenone
Sinocure® PBZ 2128-93-0 4-Benzoylbiphenyl
Sinocure® OMBB/MBB 606-28-0 Methyl 2-benzoylbenzoate
Sinocure® 784/FMT 125051-32-3 BIS(2,6-DIFLUORO-3-(1-HYDROPYRROL-1-YL)PHENYL)TITANOCENE
Sinocure® BP 119-61-9 Benzophenone
Sinocure® 754 211510-16-6 Benzeneacetic acid, alpha-oxo-, Oxydi-2,1-ethanediyl ester
Sinocure® CBP 134-85-0 4-Chlorobenzophenone
Sinocure® MBP 134-84-9 4-Methylbenzophenone
Sinocure® EHA 21245-02-3 2-Ethylhexyl 4-dimethylaminobenzoate
Sinocure® DMB 2208-05-1 2-(Dimethylamino)ethyl benzoate
Sinocure® EDB 10287-53-3 Ethyl 4-dimethylaminobenzoate
Sinocure® 250 344562-80-7 (4-Methylphenyl) [4-(2-methylpropyl)phenyl] iodoniumhexafluorophosphate
Sinocure® 369 119313-12-1 2-Benzyl-2-(dimethylamino)-4′-morpholinobutyrophenone
Sinocure® 379 119344-86-4 1-Butanone, 2-(dimethylamino)-2-(4-methylphenyl)methyl-1-4-(4-morpholinyl)phenyl-
Sinocure® 938 61358-25-6 Bis(4-tert-butylphenyl)iodonium hexafluorophosphate
Sinocure® 6992 MX 75482-18-7 & 74227-35-3 Cationic Photoinitiator UVI-6992
Sinocure® 6992 68156-13-8 Diphenyl(4-phenylthio)phenylsufonium hexafluorophosphate
Sinocure® 6993-S 71449-78-0 & 89452-37-9 Mixed type triarylsulfonium hexafluoroantimonate salts
Sinocure® 6993-P 71449-78-0 4-Thiophenyl phenyl diphenyl sulfonium hexafluoroantimonate
Sinocure® 1206 Photoinitiator APi-1206

 

UV ink raw materials : UV Monomer Same series products

Sinomer® ACMO 4-acryloylmorpholine 5117-12-4
Sinomer® ADAMA 1-Adamantyl Methacrylate 16887-36-8
Sinomer® DCPEOA Dicyclopentenyloxyethyl Acrylate 65983-31-5
Sinomer® DI-TMPTA DI(TRIMETHYLOLPROPANE) TETRAACRYLATE 94108-97-1
Sinomer® DPGDA Dipropylene Glycol Dienoate 57472-68-1
Sinomer® DPHA Dipentaerythritol hexaacrylate 29570-58-9
Sinomer® ECPMA 1-Ethylcyclopentyl Methacrylate 266308-58-1
Sinomer® EO10-BPADA (10) ethoxylated bisphenol A diacrylate 64401-02-1
Sinomer® EO3-TMPTA Ethoxylated trimethylolpropane triacrylate 28961-43-5
Sinomer® EO4-BPADA (4) ethoxylated bisphenol A diacrylate 64401-02-1
Sinomer® EOEOEA 2-(2-Ethoxyethoxy)ethyl acrylate 7328-17-8
Sinomer® GPTA ( G3POTA ) GLYCERYL PROPOXY TRIACRYLATE 52408-84-1
Sinomer® HDDA Hexamethylene diacrylate 13048-33-4
Sinomer® HEMA 2-hydroxyethyl methacrylate 868-77-9
Sinomer® HPMA 2-Hydroxypropyl methacrylate 27813-02-1
Sinomer® IBOA Isobornyl acrylate 5888-33-5
Sinomer® IBOMA Isobornyl methacrylate 7534-94-3
Sinomer® IDA Isodecyl acrylate 1330-61-6
Sinomer® IPAMA 2-isopropyl-2-adamantyl methacrylate 297156-50-4
Sinomer® LMA Dodecyl 2-methylacrylate 142-90-5
Sinomer® NP-4EA (4) ethoxylated nonylphenol 2156-97-0
Sinomer® NPGDA Neopentyl glycol diacrylate 2223-82-7
Sinomer® PDDA Phthalate diethylene glycol diacrylate
Sinomer® PEGDA Polyethylene Glycol Diacrylate 26570-48-9
Sinomer® PEGDMA Poly(ethylene glycol) dimethacrylate 25852-47-5
Sinomer® PETA PETA Monomer 3524-68-3
Sinomer® PHEA 2-PHENOXYETHYL ACRYLATE 48145-04-6
Sinomer® PO2-NPGDA NEOPENTYL GLYCOL PROPOXYLATE DIACRYLATE 84170-74-1
Sinomer® TEGDMA Triethylene glycol dimethacrylate 109-16-0
Sinomer® THFA Tetrahydrofurfuryl acrylate 2399-48-6
Sinomer® THFMA Tetrahydrofurfuryl methacrylate 2455-24-5
Sinomer® TMPTA Trimethylolpropane triacrylate 15625-89-5
Sinomer® TMPTMA Trimethylolpropane trimethacrylate 3290-92-4
Sinomer® TPGDA Tripropylene glycol diacrylate 42978-66-5

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