MELCROSS 21       

Commercial name

Application

MELCROSS 21
High Methylol type Resin

MELCROSS 21 is a high methylol type methylated melamine- formaldehyde resin for water soluble and general purpose enamels of industrial paints and coil coatings.

 
MELCR
OSS-21 is designed as good crosslinker for most polymers which contained hydroxyl and amide groups.  But there is a little limit on carboxyl groups.  High methylol group derives good reactivity and water soluble properties for the coating formulations.
This resin is reduced in isobutanol and can be utilized as crosslinking agents for both solvent and water based coatings.

Typical properties

Appearance

 

Clear, viscous liquid

Non-volatile

  Wt. %

   78-82

Solvent

 

  Isobutano

Color, Gardner1963

 

  Max. 1

Viscosity, Cone/Plate

   cps

  2300-9800

Specific gravity

   25C

   1.16

Flash point, Closed cup

    F

    115

Methylol content

 

    High

Free Formaldehyde

   Wt.%

   Max.3.5

Application
W
ater soluble enamel with water soluble anionic polymers.
General industrial baking enamels.
Coil coating.
Varnish for wood .

Introduction
MELCROSS-21 crosslinking agent is a commercial grade of methylated melamine-formaldehyde resin with a high methylol  functionality content  and insolved in the isobutanol solvent.
The advantages of MELCROSS-21 are rapid cure,  higher solids enamels,  gloss and gloss retention,  good stability, chemical resistance in coating areas.
This resin requires only weak acid catalyst for cure at normal baking schedules.   Used in both aqueous and solvent-born coatings due to excellent balance between compatibility and cure response.  Showing a high tendency towards self condensation .
To control the stability, you can use tertiary amins for neutralisation and PH adjustment.
A low acid number in an alkyd or acrylic resin is sufficient. The cure reaction can be additionally catalyzed with weak organic or inorganic acids such as maleic, citric, phosphoric, or alkyl phosphoric acids, low levels of para toluene sulfonic acid catalyst.
Acid catalyzed coatings may be cured as low as 100C.

MELCROSS-21 cure similary to butylated melamine resins.
They also have a tendency to self-condense.  Higher film hardness may be easily obtained by raising the level of amino crosslinking agent.

SAFETY
General
Attention must be paid to the normal precautions for handling chemicals and to the measures prescript in the local health regulations.  The work place must be well ventilated, skin care measures should be adapted and safety google should be worn.

    Safety data sheet
P&ID Co.,LTD shall provide MSDS associated with MELCROSS -21  as your request. MSDS of MELCROSS-21

    Storage
If MELCROSS-21 is kept in tightly closed drums or in storage tanks in the cool place, its shelf life is 12 months.

    RemarK
 This information is given without any warranty or representation. We do not assume any legal responsibility for same, nor do we give permission, inducement, or recommendation to practice any patented invention without a license.   It is offerd solely for our consideration, investigation and verification.  Before using any product, read its label.