Urea-melamine-cyclohexanone-formaldehyde resins

   Butanolated urea-formaldehyde resins are produced as 50-60% solutions in butanol or mixed butanol and xylene, solvent-naphtha, cellosolve; among them: butanolated resins K-411-02, K-411-02SB, and K-411-02KB. Weakly butanolated resin K-411-03 is also produced which is intended for use in production of varnishes and enamels with low drying temperatures.  Mixture of solvent-naphtha with butanol and ethanol is used as a solvent for this resin. Plasticizing is mostly carried out by means of combination with hydroxyl polyesters, in particular with alkyd resins.

   In the process of hardening reactive groups of urea-formaldehyde resin and polyester interact forming a cross-linked structure coating. Paintwork materials based on urea-formaldehyde resins in combination with polyesters are used to make coatings on wooden and metal goods.

   Paintwork materials based on mixed melamine-formaldehyde and alkyd resins have superior light-, weather-, and thermal resistance compared to alkyd and urea-alkyd materials. Melamine-alkyd enamels form coatings capable to retain not only protective but also decorative properties (color and gloss) during a long time under weather conditions of tropical, northern, and moderate climate.

   Cost of melamine-alkyd materials is higher than that of urea-alkyd ones, but they reach required hardness 20-40 % quicker than urea-alkyd materials. They form coatings as mar-proof as urea-alkyd materials, but  which are considerably superior  in gloss, spreading, soap-and weak alkali resistance. Essential advantage of melamine-alkyd coatings over urea-alkyd coatings is better resistance to color change when heated to 140-175°С and good weather resistance (color- and gloss retention, cracking resistance) under conditions of not only moderate but also tropical climate.

    Depending on the required drying temperature paintwork material formulation will contain melamine-formaldehyde resins of different reactivity. Thus, for example, for enamels with drying temperature 130°С highly butanolated resin K-421-02 can be used, and for enamels with drying temperature 100°С – more reactive weakly butanolated resin K-423-02.  In some cases, e.g. during repair works and spot finishing on assembled cars, drying should be carried out at a temperature not exceeding 85°С during 30 minutes. One of the ways to meet this requirement is introduction of acid catalyst in enamel formulation. Good results were obtained when using 2-4% dibutyl phosphoric – or butyl phosphoric acid (50% solution in xylene) as a hardener which does not cause metal corrosion and ensures coating sufficiently hard (0,4-0,6) and with good tint stability. The shortcoming of this method is that light tone enamels may display insignificant tone variation. To improve spreading of melamine-alkyd automotive enamels it is recommended to add organic silicone liquids into them and to select solvent components very carefully. 

   Cyclohexanone- formaldehyde resins are thermoplastic polymers. They may differ in degree of condensation, solubility and accordingly are used as auxiliary binders in production of nitrocellulose- and alkyd enamels. 

Urea- melamine-cyclohexanone-formaldehyde resins

•  Chimplast-TsGF cyclohexanone-formaldehyde resin
  
• Butoxylated urea-formaldehyde resins K-411-02,К-411-02SB,К-411-02SB-М, К-411-02SB-V,К-411-02KB
• Butoxylated urea-formaldehyde resin K-411-03
• Butoxylated melamine-formaldehyde resins К-421-02, К-421-02КB
• K-423-02 weakly butanolated melamine-formaldehyde resin
• MKF-50 melamine-urea-formaldehyde resin