Modifiziertes Phenolharzpraeparat

摘要

A composition suitable for use as a coating comprises a resole phenol-aldehyde condensation product and, for each 100 parts by weight thereof, from 5 to 200 parts by weight of a thermoplastic polyhydroxyether having the general formula wherein D is the radical residuum of a dihydric phenol, E is an hydroxyl containing residuum of an epoxide and n is an integer of at least 30, or a mixture of such polyhydroxy ethers. The phenol-aldehyde condensation product is preferably a heat-reactive B-stage resole resin and has an average M.W. of from 350 to 600. Conventional phenols and aldehydes are listed. The value of n in the formula of the polyhydroxyether is preferably at least 80 and such polyhydroxyethers may be prepared by reacting together approximately equimolar amounts of an epihalohydrin and a dihydric phenol in the presence of an alkali metal hydroxide. Suitably the dihydric phenol is a dihydric polynuclear phenol such as 2,2-bis(4-hydroxyphenyl) propane or it can be the reaction product of 4-vinyl-cyclohexene and a phenol or of dipentene and a phenol. The epoxide may be a monoor diepoxide, suitably epichlorohydrin and in the case of the diepoxides those wherein each of the oxirane groups is connected to an electron donating substituent which is not immediately connected to the carbon atoms of that oxirane group. For use as coatings the compositions may be dissolved in an organic solvent system, spread on the article to be coated and then cured. Suitable solvents are ketones and toluene and mixtures of the two.ALSO:Compositions suitable for coating surfaces of metal, wood glass or fabrics comprise a resole phenol-aldehyde condensation product and, for each 100 parts thereof, from 5 to 200 parts by weight of a thermoplastic polyhydroxyether having the general formula: wherein D is the radical residuum of a dihydric phenol, E is an hydroxyl containing radical residuum of an epoxide and n is an integer of at least 30, or a mixture of such polyhydroxyethers, suitably dissolved in an organic solvent system. The solvent based coatings are generally cured at 400 DEG F. to 450 DEG F. for maximum adhesion. Examples describe the coating on steel panels and on glass plate of compositions of a polyhydroxyether prepared from 2,2-bis(4-hydroxyphenyl)-propane and epichlorohydrin with (i) a phenol: cresol-formaldehyde resole resin or (ii) a phenol: polyhydric compound - formaldehyde resole resin wherein the polyhydric compound has the formula: Suitable solvents for the compositions are ketones and mixtures of ketones with e.g. toluene or butanol.