Un tipo común de renovación es el repintado, y la eliminación de capas antiguas de pintura o revestimientos es un paso importante en la remodelación o renovación para mejorar el atractivo visual y maximizar la protección de la superficie subyacente. Los decapantes y removedores de pintura son fundamentales para garantizar que el proceso de repintado se desarrolle sin problemas.

Formulaciones de decapantes y removedores de pintura

Las formulaciones de decapantes de pintura y revestimientos se basan en un disolvente o una mezcla de disolventes para disolver las capas antiguas de pintura, barniz y revestimiento, lo que facilita su eliminación mediante raspado o desprendimiento. Antes de 2024, el disolvente más común para formular decapantes era el cloruro de metileno, que penetraba y expandía las películas de pintura con gran fuerza, lo que facilitaba su eliminación. Desde entonces, la EPA de EE. UU. ha prohibido su uso en formulaciones de decapantes de pintura, lo que ha impulsado la exploración de otros disolventes.

Además de los disolventes, las formulaciones de decapantes también incluyen aditivos como espesantes, responsables de modificar la viscosidad, una característica clave que distingue la calidad del rendimiento de un decapante. Los decapantes optimizados para la viscosidad ofrecen una buena capacidad de esparcimiento, lo que facilita la aplicación del producto y minimiza el desperdicio. En muchos casos, añadir el espesante adecuado a la formulación de un decapante o removedor resulta en un producto de calidad significativamente superior.

Espesantes METHOCEL™ y ETHOCEL™

METHOCEL™ y ETHOCEL™ son espesantes de origen natural basados en celulosa de pulpa de madera renovable. METHOCEL™ es un polímero de hidroxipropilmetilcelulosa, y ETHOCEL™ es un polímero de etilcelulosa. A partir de celulosa alcalina, METHOCEL™ se fabrica mediante un tratamiento para sustituir grupos hidroxipropilo y metilo en la cadena principal de celulosa, mientras que ETHOCEL™ se fabrica mediante un tratamiento para sustituir grupos etilo en la cadena principal de celulosa.

En general, METHOCEL™ se recomienda para soluciones que contienen una mezcla de solventes orgánicos y agua, mientras que ETHOCEL™ se recomienda para soluciones que solo contienen solventes orgánicos.

These thickeners have been relied on for several decades to provide rheology modification and thickening in a variety of applications, including paints and coatings, adhesives, and ceramics. In paint remover applications, specific attributes make them ideal for optimizing performance: 

• Shear-thinning rheology modification 
• Excellent solubility in aqueous and various organic-solvent-based solutions 
• Chemical inertness and safety 

Shear-Thinning Rheology Modification

When METHOCEL™ and ETHOCEL™ are added to aqueous- or solvent-based solutions, they increase viscosity and impart shear-thinning rheology. As previously mentioned, viscosity is an important performance attribute for paint strippers to minimize waste and make the product easier to apply. 

When paint strippers are applied to vertical or overhead surfaces, formulations with insufficient viscosity will cause sagging and dripping, leading to waste and ineffective coverage. In this case, METHOCEL™ and ETHOCEL™ serve two purposes: they make brush or spray application easier while the formula is under high shear, and they rebuild viscosity and keep the formula in place when it is left on the surface and shear is removed. 

 

Excellent Solubility in Various Solvents

 

Depending on which solvent is being used in each paint, varnish, or coating stripper formulation, selecting the right product is critical to achieving a solution that is clear, smooth, and easy to spread. METHOCEL™ and ETHOCEL™ are recommended for paint stripper applications because one or the other will provide excellent solubility in a wide range of solvents and solvent blends. As mentioned, METHOCEL™ performs better in organic solvent–water blends, and ETHOCEL™ performs better in organic solvents. 

Below is a chart detailing the compatibility and appearance of METHOCEL™ 311 and ETHOCEL™ Standard 300 in various solvents and solvent blends. METHOCEL™ and ETHOCEL™ also reduce the evaporation rate when added to these solvents, leading to higher contact times with the surface and extended efficacy. 

 

Solvent	METHOCEL™ 311	ETHOCEL™ Standard 300
Ethanol	Hazy, gels	Clear, smooth
Methanol	Hazy, gels	Clear, smooth
Ethanol/water (40/60)	Clear, smooth	Insoluble
Methanol/water (40/60)	Clear, smooth	Insoluble
THF	Swellable	Clear, smooth
THF/water (60/40)	Clear, smooth	Insoluble
Isopropanol	Insoluble	Clear, smooth
Isopropanol/water (80/20–40/60)	Clear, smooth	Clear, smooth to insoluble
Propylene glycol	Insoluble	Insoluble
Propylene carbonate	Clear, smooth	No data
Furfuryl alcohol	Clear, smooth	No data
Dimethyl formamide	Clear, smooth	Clear, smooth
DOWANOL™ PM	Hazy, gels	Clear, smooth
Benzyl alcohol	Hazy, gels	Clear, smooth
Diethylene glycol butyl ether	Insoluble	Clear, smooth
Dimethyl carbonate	Insoluble	Clear, smooth
Dimethyl sulfoxide (DMSO)	Insoluble	Clear, smooth
CELLOSOLVE™	Swellable	Clear, smooth

Chemical Inertness and Safety

As consumer safety becomes a greater focus for paint stripper and paint remover formulations, it is important to limit hazardous ingredients. METHOCEL™ and ETHOCEL™ are naturally derived products that are safe to use and pose minimal risk to the formulator. Contact us for additional product details or safety data sheets.

Recommended Grades and Example Formulations

Below are recommendations and example formulations utilizing METHOCEL™ and ETHOCEL™ grades in paint and coating stripper formulations.
 

Recommended grade	Usage level (%)	Notes
METHOCEL™ 311	0.5–1.5	METHOCEL™ 311 is designed for higher solubility in organic solvents while maintaining full solubility in water.
METHOCEL™ E10M	1.0–2.5	METHOCEL™ E10M requires some water in the formulation to perform well.
ETHOCEL™ Standard 300	1.5–2.5	ETHOCEL™ Standard 300 is designed for organic solvents not blended with water.

Component	Amount (%)
Solvent/solvent blend	95.0–97.0
Surfactant	0.3–2.0
METHOCEL™ 311	1.0–3.0

 

Component	Amount (%)
Dimethyl carbonate (DMC)	58.8
Dimethyl sulfoxide (DMSO)	19.6
Xylene	19.6
ETHOCEL™ Standard 300	2.0

 

Component	Amount (%)
Benzene methanol (benzyl alcohol)	78.4
Diethylene glycol monobutyl ether	19.6
ETHOCEL™ Standard 300	2.0

 

Summary

METHOCEL™ and ETHOCEL™ are ideal thickeners and rheology modifiers for paint stripper formulations because they provide shear-thinning rheology modification and are safe, naturally derived, and soluble in a wide variety of organic solvents and solvent–water blends. This leads to paint stripper formulations that last longer, adhere to various surfaces more efficiently, and are safer and easier to formulate. Click below to discuss your paint stripper or remover application and request a sample today.