Patent GB-768028-A (GB)
Title: Improvements in or relating to alkylated catechol and compositions comprising the same
Inventor: PARKER EARL ELMER
IPC: C09D7/46
Filed: 1953-10-13
Abstract: Compositions comprise a polymerizable polyester of an alpha-beta ethylenically unsaturated dicarboxylic acid and a glycol, and 3-isopropyl catechol as a gelation inhibitor (see Group IV (b)).  The compositions may also include a polymerizable ethylenically unsaturated compound and the polyester may be modified by a saturated dicarboxylic acid.  Representative of unsaturated acids used in preparing the polyesters are maleic, fumaric, mesaconic, citraconic, ethyl maleic, pyrocinchonic, xeronic and itaconic acids, the chlorine substituted derivatives thereof and the anhydrides where such exist. Dihydric alcohols used in preparing the polyesters are ethylene, diethylene, triethylene, polyethylene, 1,3-trimethylene, 1,2-propylene, dipropylene, butylene and styrene glycols and the halogen substituted, e.g. the monochloro dihydric alcohols. Dicarboxylic acids free from ethylenic and acetylenic unsaturation which may be employed in preparing the polyesters are phthalic, tetrachlorophthalic, succinic, adipic, suberic, azelaic, sebacic and dimethyl succinic acids and chlorinated derivatives of succinic and dimethyl succinic acids and the corresponding anhydrides may be employed.  A monobasic acid may also be employed in preparing the polyester, e.g. linoleic, linolenic, eleostearic, octadecatrienoic, clupanodonic, acetic and propionic acid. Representative of the monohydric alcohols which may be employed in preparing the polyesters are ethyl, allyl, lauryl, oleyl and benzyl alcohols.  Polymerizable ethylenically unsaturated compounds mentioned which may be mixed with the polyesters include styrene, a -methyl styrene, p-methyl styrene, divinyl benzene, indene, vinyl acetate, methyl methacrylate and acrylate, allylacetate, diallyl phthalate, succinate, adipate, sebacate, diethylene glycol bis-(allyl carbonate), triallyl phosphate, esters of alcohols, e.g. of methyl, ethyl, propyl, allyl or methallyl or vinyl alcohols, or polyhydric alcohols, with unsaturated polymerizable monocarboxylic acids, e.g. acrylic, methacrylic or chloracrylic acid and other esters of monohydric unsaturated alcohols e.g. allyl, vinyl, methallyl, 2-chlorallyl and crotyl alcohols with mono- or polycarboxylic acids, e.g. acetic, propionic or succinic acids and esters of e.g. maleic, fumaric, or itaconic acids with e.g. methyl, ethyl, propyl, isopropyl and amyl alcohols.  The 3-isopropyl catechol is usually added to the ethylenically unsaturated compound before adding the latter to the polyester.  The mixture may be polymerized by heating, optionally with a catalyst such as benzoyl peroxide, tertiary butyl peroxide and hydroperoxide, cyclohexyl, acetyl, or lauroyl peroxide, or by exposure to ultra-violet light.  Gelation inhibitors, e.g. quinone may be present in vinylic starting materials.  In the examples the polyester resins are cured in two temperature stages and fillers such as wood flour, titanium dioxide and calcium carbonate may be present. Laminates of cotton or glass fabrics may be produced or coatings may be applied to wood, metal or paper.  The 3-isopropyl catechol also acts as anti-skimming agent in an oil- and rosin-modified alkyd (of maleic acid) containing lead/cobalt driers.ALSO:The invention comprises 3-isopropyl catechol which may be prepared by condensing catechol and isopropyl alcohol in the presence of a dehydration catalyst, e.g. sulphuric acid or fluosulphonic acid.  4-Isopropyl catechol and diisopropyl catechol are obtained as by-products.  In an example 3-isopropyl catechol is produced by reacting catechol and isopropyl alcohol in the presence of sulphuric acid and water under reflux.  3-Isopropyl catechol is employed as an anti-skimning agent in paints or varnishes containing drying oils (see Group III) and in compositions comprising a polymerizable polyester of an alpha-beta ethylenically unsaturated dicarboxylic acid and a glycol (see Group IV (a)).ALSO:A paint or varnish contains drying oils and 3-isopropyl catechol (see Group IV(b)) as antiskinning agent.  Coating compositions mentioned comprise alkyd resins modified with glyceride drying oils or the partial esters, e.g. mono- and di - glycerides of oils such as linseed, soya and cedar nut oil. Skinning in conjugated oils such as oiticica or tung oil may be inhibited.  The oils may be modified with ester gum, phenol-formaldehyde resins and alkyl resins. The compositions may contain driers such as oleates, linoleates and naphthenates, and soluble organic salts of cobalt, lead, nickel, manganese and chromium.  In examples: 3 - isopropyl catechol is employed in compositions comprising (II) linseed oil, a polyester of penta-erythritol, maleic acid and rosin, mineral spirits or naphtha and lead or copper naphthenate; (III) ester gum, tung oil, mineral spirits and as driers organic salts such as naphthenates and oleates of cobalt and lead; (IV) tung oil, a soluble phenol formaldehyde resin, mineral spirits and cobalt and lead driers. The use of orthoamyl phenol in compositions similar to (II) is referred to.