Patent GB-961029-A (GB)
Title: Surface coating compositions
Inventor: MACIVER DONALD RODERICK
IPC: C09D155/04
Filed: 1960-03-15
Abstract: Water soluble coating compositions contain: (a) reaction product of a compound functioning as an unsaturated oil and a compound having an acyclic olefinic carboxylic acid residue, with or without the addition of minor amounts of dienes, the product being soluble in aqueous base; (b) a water-soluble phenol-aldehyde condensate, the component (b) forming not more than 45%, preferably 5-25% of total weight of (a) and (b).  The compound functioning as an unsaturated oil is the triglyceride ester of an unsaturated fatty acid having at least 12 carbon atoms in the unsaturated chain, or a derivative e.g. the fatty acids and their other esters.  Suitable oils are tung, oiticica, linseed, soya, cotton seed, dehydrated castor, perilla, tall and fish oils.  The compound having an acyclic olefinic carboxylic acid residue has less than 10 carbon atoms in any chain, and is an acid or derivative, e.g. anhydride or ester.  Dicarboxylic acids are preferred, e.g. maleic, fumaric, aconitic, itaconic, alkyl-substituted maleic.  Acrylic acid may be used, as may citric in conditions where it yields itaconic acid or citraconic anhydride. Suitable dienes are cyclopentadiene, butadiene, cashew nut shell oil, gum resin, myrcene.  Suitable bases are alkali metal hydroxides, ammonia, and primary, secondary and tertiary aliphatic amines. A volatile base such as ammonia is preferred. Conditions of reaction for preparing (a) are described in Specification 500,349 and U.S.A. Specification 2,414,712. Temperatures of 110-300 DEG C. are suitable, 200-240 DEG C. being preferred when linseed oil and maleic anhydride are reacted. 15-35% of maleic anhydride based on total weight of linseed oil and maleic anhydride is suitable.  The condensate has a phenol-aldehyde molar ratio of 1:1-1:3 and has a water tolerance of 0.5 ml. H2O/gm.; i.e., at 25 DEG C., at a final pH of 9, 0.5 ml. H2O may be added to 1 gm. of resin before turbidity is produced. Preferred condensates are those prepared from formaldehyde and phenol and/or cresols in the presence of alkali.  They are most suitably prepared in water. Additional base may be added.  The aqueous coating composition contains 15-70%, preferably 40-60%, by weight, of (a) plus (b), and are curable by heating. Metallic driers, fillers, pigments and plasticizers may be added.  The examples describe the preparation of an adduct from 76 parts linseed oil and 24 parts maleic anhydride by heating at 200 DEG C. for 4 hours under nitrogen. 113 parts water and 24 parts of ammonia (density 0.91 g/ml.) and 1.01 parts of cobalt drier added.  A condensate is prepared from 24 parts phenol, 4 parts water, 1.4 parts triethylamine and 12.3 parts formalin (78.6%) at 70 DEG C. until a water tolerance of 4 ml/gm. is reached.  The solutions are mixed in various proportions and pigmented with red oxid, barytes, strontium chromate, talc, asbestine, micronised mica titanium dioxide, and magnesium montmorrillonite (anti-setting agent).ALSO:Water-soluble coating compositions contain: (a) the reaction product, soluble in aqueous base, of an unsaturated glyceride oil or derivation thereof e.g. the free acids or other esters of them with a compound having an acrylic olefinic carboxylic acid residue (e.g. acrylic, maleic, fumaric, aconitic, itaconic, citraconic acids, their anhydrides or esters) with or without the addition of a diene, natural or synthetic; (b) a heat-reactive, water-soluble phenol (1 mole)-aldehyde (1 - 3 moles) condensate (for details of (a) and (b) see Division C3 abridgement). The condensate forms not more than 45%, preferably 5-25%, of the total weight of (a) and (b).  The composition contains 15-70%, preferably 40-60%, by weight, of (a) and (b).  Metallic driers, fillers, plasticizers and pigments may be added.  The coatings may be used to prepare stoving primers and primer-surfaces, are curable by heating, and may be used to coat metal surfaces.  In the examples, a linseed oil-maleic anhydride adduct to which ammonia and 0,06% of cobalt as drier, is mixed with a phenol-formaldehyde condensate to give a ratio of phenolic resin to total solids of: Example 1, 9,1; Example 2, 13,8; Example 3, 16,7; Example 4, 20,0; Example 5-24,8; control-0,0. To 33,2 parts of the resultant solutions were added 9,6 of red oxide, 17,4 of barytes, 4,9 of china clay and 4,9 of micronized mica, followed by a further 14,5 parts of the solutions and 15 parts of water.  Steel panels were coated with the compositons to test for water resistance.  Further formulations are made as follows (figures in brackets refer to parts by weight): (I) solution of Example One (6,0); strontium chromate (1,3); red oxide (14,3); barytes (8,5); talc (2,9); magnesia montmorillonite (0,2); water (12,1), and a further 54,6 parts of solution of Example (1); (II) solution of Example One (45,9); strontium chromate (1,9); red oxide (19,8); barytes (11,7); talc (3,9); anti-settling agent (0,2); water (16,6); (III) solution of Example One (45,9); red oxide (20,9); barytes (12,5); talc (3,9); anti-settling agent (0,2); water (16,6); (IV) solution of Example One (42,1); strontium chromate (1,5,); titanium dioxide (14,0); barytes (14,7); asbestine (3,8); talc (4,7); anti-settling agent (0,5); water (18,7); (V) solution of solids content 55% (37,6); red oxide (20,9); barytes (12,5); talc (3,9); anti-settling agent (0,2); water (24,9).  For "wet on wet" application, a slipper dip of formulation I may be applied to mild steel, followed by a spray of formulation IV at 75  DEG C.  The compositions may be used to coat: metal toys or furniture; iron drain pipes; steel strip direct from hot mill; domestic appliances; lighting fittings; cycles and motor cycles; lawn mowers and horticultural equipment; ammunition; transformers and electric motor core stampings; hot water radiators; metal window frames; electric motor housings; fan blades; and metal canisters.  Specification 500,349 is referred to.