Novel epoxy resins based on cyclohexanone‐aldehyde condensation products

Abstract

SynopsisSolid ketone-formaldehyde resins are used in certain coating formulations in order to improve hardness, gloss, and light stability. They are soluble, thermoplastic by nature, and contain limited amounts of hydroxyl groups. We found that their primary hydroxyls can be etherified with epichlorohydrin (ECH) either by a two-step ECH-addition/dehy&ohalogenation procedure or by a one-step phase-transfer process. An intermediate of particular usefulness is the crystalline 2,2,6,6-tetramethylol-cyclohexanol (TMCH) made from cyclohexanone and 5 mol formaldehyde, yielding low colored epoxy resins with epoxy values up to 7.5 eq/kg. Depending upon the nature of the curing agent, high Tp solids as well as tough and flexible coatings with good outdoor stability can be made. Upon decreasing the formaldehyde-cyclohexanone ratio, solid condensation polymers melting up to 150°C can be obtained. Phase-transfer glycidylation yielded solid thermoset glycidyl ether resins with a,, up to 1600, up to 13,000, epoxy values up to 3.6 eq/kg, and softening points between 80 and 160°C. Powder coatings formulated with carboxyterminated polyesters are hard, glossy, solvent-resistant but somewhat brittle. In order to overcome this drawback, polycycloacetals have been produced from TMCH and glutardialdehyde, which are terminated by pairs of methylol groups. Powder coatings of the corresponding glycidylethers with carboxyl-terminated polyesters exhibited excellent flexibility and impact strength.

Synthesis of cyclohexanone formaldehyde resin‐methylmethacrylate block‐graft copolymers via ATRP

“…Cyclohexanone‐formaldehyde resin (CFR) has good utility because it has excellent glossy and transparent properties 3, 4. Due to their high compatibility and solubility with wide range of film formers, resins (CFR) play a key role in the field of coatings (paints, inks, varnish, lacquers,7–11 and light stabilizers,12) as a blend for the improvement of coating properties,13–15 and as an adhesive in multilayered laminated sheets. Synthesis of ketonic resin containing copolymers has been extensively studied16–24 since the ketonic resin segments improves adhesive, solubility, gloss, and light stability of parent polymers.…”

Novel Phenol‐Formaldehyde Resins, 2. Resols Prepared Using Reactive Solvents

“…Not only formaldehyde, but also ketone parts of the reactive solvent were found built into the structure of resulting polymers. [2] The multihydroxymethyl derivatives of ketones are used not only as the reactive solvents of melamine, but also as components in manufacturing phonographic tapes, [3,4] thermoplastics of porous structure, [5] decorative coatings for candles, [6] new epoxy resins, [7] surface-tension-reducing agents, [8][9][10][11][12][13][14][15][16][17][18][19][20][21] thermoinsulating coatings for semiconductors [21] and ''reinforced'' glass. [22] The reactive solvents can be used for liquefying other heterocyclic compounds [23] and phenol.…”

Novel unsaturated polyester resins based on (maleated cyclohexanone-formaldehyde resin)-(epoxy resin) condensation

“…This is usually used as coating additive [6][7][8], free radical photoinitiators [9], as a blend for the improvement of coating properties [10][11][12] and as an adhesive in multilayered laminated sheets [13]. A wealth information on modifying the CHF resins for its applications in various areas is available [14][15][16][17][18][19][20][21][22][23]. However the use of these modified CHF resins in certain specific fields has not been extensively covered.…”