IL24408A - Anti-corrosive paint compositions - Google Patents

Description

paint compositions 3373 The present invention concerns paint compositions for especially compositions offer excellent protection against corrosion and can serve both as base or primer paints and also as finish Paint compositions of the kind with which the present invention is concerned comprise binders such for and at least one pigment acting as protective From among known paint compositions there may be mentioned in particular those containing as pigment either alone or in combination with other as well as those in which the pigment is red lead Known paints that serve as base or primer paints not fully during the curing the binder which may take a week o even protection against stron atmospheric attack is insuf the lifetime o protective coats produced from known primer paints is in if they remain under corrosive conditions without a top for an iron substratum with an uneoated coat develops rust after some know protective primer coats such for romate and red lead oxide coats are vulnerable to attack by corrosive agents such for It is the object of the present invention to provide new improved paint compositions which yield protective coats that if be left without a invention consists in paint compositions containing at least one fluoride of the in which Me is or Zn and n is 2 in case He is and in case is which fluorides may contain water of the purpose of the present invention the above fluorides as a not be completely pure and can be used in a technical grade It has already been proposed to use fluorides of various alkali or alkali earth metals as well as manganese as pigments or pigment ingredients in paint compositions for example Freneh patent specification these fluorides turned out to be unsuccess ful as they offer real advantage over any of the other It was therefore quite surprising to find that the protective capacities of and exceed by fa the capacities of any of the known including the fluorides disclosed in the to rench patent specification while conventional protective paint compositions contain as a rule from 20 by weight of the protective the compositions according to the invention contain a considerably smaller proportion of preferably between 2 and by the actual corrosion preventing capacity of the paint compositions according to the invention is superior to that of known paint including those described in the above It thus that used as protective agents in accordance with the invention in a manner that was completely unpredictable over fluorides that have been used in the art he paint compositions according to the invention may also contain other pigments such as red iron titanium and also fillers such for barite and The remaining ingredients of the paint compositions according to the invention are conventional and include solvents and Bach of these ingredients and any desired further additives may be selected from the wide range of products used hitherto in the the binders that can be for the formulation of protective paint compositions according to the invention include alkyd phenolic epoxy chlorinated polyvinyl copolymers and many Quite generally the preferred general composition of paints according to the invention is as Zinc fluoride chromium fluoride 2 10 Filler other pigments 10 Binde solids 14 Solvents and driers Balance As a the nature the binder and the relative proportions of the ingredients will depend on the conditions to which the primer coat is to be in some cases it will be preferable to use long oil alkyd resin as to use a relatively large proportion cases it may be preferable to use as binder short phenolic resin to use relatively small proportion of zinc chromium fluoride and to incorporate in addition also other pigments such as sind in order to obtain in this way good resistance against acidic In still other cases a medium oil resin will be used as binder in combination as further pigment in order to obtain good resistance to underwater Comparative tests carried out with protective coats produced with paint according to the invention on the one hand and conventional and red protective coats on the other using in each case mechanically cleaned steel or iron as have shown that the former are superior to latter i the following Resistance to even in the presence of gaseous chlorides and ammonium sulphate i the Resistance under mild acidic conditionsj Resistance in the presence of a sal spra Resistance without top coat for at least three months to severe weathering and other Resistance to both weathering and corrosion when covered with alkyd top coat Resistance to weathering and corrosion when using varnishes or which is of Chromium fluoride is known in two different differing from each other by their water or the purposes of the present invention the less soluble modification to be somewhat more suitable than the other one but nevertheless both forms may Especially useful is a fluoride obtained from by dehydration at a temperature of a water content reduction of about 20 form will be qualified in the following examples as invention is illustrated by the following Examples without being limited all indications o quantities being in parts by Example 1 following composition Chromium fluoride Mineral siccatives A paint of this time of seven kept a steel panel intact in a saltspray for one thousand and in a humidity chamber for about twenty 2 following composition was 100 Chromium luoride hemiheptahydrate 4 Potassium 104 Zincoxide 50 Talc 2 Mineral spirits and siccatives 71 Shis paint was force dried in one coat over a clean steel panel and ted corrosion in a saltspray for more than one thousand She same paint air dried resisted corrosion in a humidity chamber for more than Example 5 The following composition was Alkyd 200 Zincoxide 100 Chromium dehydrated Aluminiumstearate 2 Mineral turpentine and siccatives 71 A steel panel coated with a single coat of this composition and dried for 7 days resisted 1000 hours humidity chamber exposure without change and also days of saltspray ex If in Example 3 the dehydrated chromium fluoride is substituted by parts of chromium fluoride hemiheptahydrate the humidity resistance is obtained as in Example while the resistance to saltspray for days following composition 300 200 Calcium carbonate Chromium fluoride heptahydrate 24 6 turpentine siccatives 220 A panel coated with a single coa of this paint resisted 20 days in a huiaidity chamber and 25 days of saltspray 6 following composition was Alkyd 200 Zinc fluoride 22 Zinc oxide 111 100 Talcum 32 Aluminiurastearate 4 turpentine siccatives 144 A steel panel coated with a single coat of thin The composition was dehydrated Polyvinylbutyral Ethanol 62 Butanol 15 solution of in acetone 62 This composition was compared with the normal and based on ainc the following silicate Butanol For this purpose both paints were applied to a steol panel and the resulting coats covered with one coat of ohroraate In the cabinet the resistance of was days and of the paint according to the invention of the above formulation about In the humidity chamber both primers did not deteriorate after about 30 Example 7 The following composition was Chromfluoride dehydrated Polyvinylbutyral 10 Ethanol 62 Butanol 15 10 solution of H PO in acetone 62 This composition was compared with the normal washprimer based on zinc chromate and having the following Zinctetroxychromate 54 Polyvinylbutyral 56 Part Magnesium silicate 8 Ethanol 380 Butanol 125 Phosphoric acid 8 28 Part B Water 28 Ethylalcohol 102 this purpose both paints were applied to a steel panel and the resulting coats covered with one coat of chromate the saltfog cabinet the resistance of WPl was 3 days and of the paint according to the invention of the above formulation about 12 In the humidity chamber both primers did not deteriorate after about 7 The following composition was dehydrated Polyvinylbutyral 10 62 tanol 15 solution of in acetone 62 This composition fas compared with the normal washprimer based on zinc chromate and having the following 54 Polyvinylbutyral 56 Part A silicate 8 Ethanol 380 Butanol 125 Phosphoric acid 85 28 Part B Water 28 Ethylalcohol 102 this purpose both paints were applied to a steel panel and the resulting coats covered with one coat of In the ealtfog cabinet the resistance of was 3 days and of the paint aecording to the invention of the above formulation about 12 In the humidity chamber both primers did not deteriorate after about 30 insufficientOCRQuality

Claims (1)

1. particularly described and ascertains the nature of our said invention and in what manner the same is to be declare that what claim An paint composition containing as protective agent a fluoride of the formul in which Me is Or or Zn and n is 2 in case Me is Sn and 3 in case Me is which fluorides may contain water of A paint composition according to Claim wherein the protective agent is A paint composition according to Claim wherein the protective agent is a product obtained by dehydrating at paint composition according to Claim the protective agent is A paint composition according to any one of 1 to wherein the relative proportion of the fluoride from 2 to by compositions according to Claim substantially as Metallic articles of whenever coated by a composition according to any one of Claims 1 to Dated this 3rd day of 1 For the Applicants insufficientOCRQuality