US 2020/0190338 Al  22  Jun. 18,2020  27.  The paint forming, pressurized dispersion defined in  claim  26,  characterized thereof, that the paint forming  dispersion is provided by admixing alongside with the  polyurethane resin and polyurethane hardener precursor also  epoxy resins and epoxy hardener precursors and wherein  said the weak acid catalyzes the reversible reaction (2a; 2a2)  between the free water present in said dispersion and poly- 24.  The method defined in any of the claims  19-23,  characterized thereof, that the adhesion of the dry paint film  is >450 psi, in PosiTest.  23.  The method defined in any of the claims  19-22,  characterized thereof, that the  dry  paint film have the Konig› hardness over 40 after 10 h and over 100 after 120 h of  drying-time, measured with pendel hardness meter.  22.  The method defined in any of the claims  19-21,  characterized thereof that the  dry  paint film is transparent  and have a gloss in the range of 10-100 preferable over 90,  under an angle of 60°.  21.  The method according to claim  19  or  20,  characterized  thereof, that weak acid (XCOOH) is added into paint form› ing dispersion an amount which will enable, after using the  can by spraying the paint forming dispersion from the can,  to enable to form a dry paint film having gloss in the range  of 10-100 from said paint forming dispersion and also  contribute to a higher adhesion to the paint surface by  etching method.  20.  The method defined in claims  19,  characterized  thereof, that the using the can comprises spraying the paint  forming dispersion out from the can for enabling water, such  as humidity, present in the surrounding environment to react  with the polyurethane hardener precursor and with the  possible epoxy hardener precursor to form a hardener com› pound with the amine and possible also with the hydroxyl  functionality and then to form on the target surface the dry  paint film.  19.  The method defined in any of the previous claims  15-18,  characterized in that, the method comprises addition› ally step of using the aerosol can by spraying the paint  forming dispersion out of the can to form a dry paint film  having a surface gloss of 5-100 preferable 10-100.  25.  The method defined any of the claims  19-22,  charac› terized in that, the Konig-hardness of the dried paint film is  over 40 after 10 h of drying time of the sprayed paint film.  26.  The paint forming, pressurized dispersion in a sealed  aerosol can said dispersion having an extended shelf life,  wherein said dispersion have been prepared with a method  defined in any of the claims  15-18  for providing a paint  forming dispersion comprising a polyurethane resin and a  possible epoxy resin, a polyurethane hardener precursor,  ketones, possible organic solvent8s), pigments, paint addi› tives, dispersion additives, propellant and providing along› side with said paint forming chemicals additionally 1-10000  ppm of free water into said sealed can;  characterized in that, the  additionally also temporary hydrolyzed products of said  polyurethane hardener precursors and possible epoxy  precursors are present in said dispersion, which hydro› lyzed products originate to the reversible reaction (2a;  2al) or (2a; 2a2) catalyzed by said the weak acid  for extending the shelf life of the dispersion, the amount  of weak acid is adapted on the basis ofH$_{2}$ 0  (free water)  present in the can, the amount of the weak acid being  in the range of 0.01-10% by weight (w/w) of the  aerosol formulation, preferably from 0.1 to 5%, still  more preferably from 0.25 to 2%;, which weak acid is  selected from the group which have the  pKa  value in the  range from 1.2 to 9.9 preferable 1.2-5.2;  polyurethane hardener precursors, are selected from the  group consisting of an imine, an enamine, a Mannich  base, a Schiff’s base, aldimine, an azole preferable an  oxazole such as an oxazolidine and mixtures thereof;  polyurethane resins are selected from the group which  composes of MDI, HDI, IPDI, TDI and phenol blocked  TDI prepolymers,  directing the obtained liquid mixture into an aerosol can,  providing the propellant and polyurethane and epoxy  resins into the can and sealing the can to obtain a paint  forming dispersion inside the can,  wherein in said method the amount of weak acid is  adapted so that it can catalyze in the reaction (2; 2a2)  the formation of the polyurethane hardener precursors  and epoxy hardener precursors from polyurethane  hardeners and epoxy hardeners in the presence of free  water (H$_{2}$ 0)  in the liquid mixture  and also to catalyze the reaction (2; 2a2) by shifting the  equilibrium of the reversible reaction (2a; 2a2), in  alternative pathways A or B, between the free water  present in said paint forming dispersion and polyure› thane hardener precursors and epoxy hardener precur› sors back to formation of said initial polyurethane  hardener and epoxy hardener and wherein  an additional amount of polyurethane hardener precursor  and epoxy hardener precursor can be added to prepare  said liquid mixture for replacing the polyurethane hard› ener precursor and epoxy hardener precursor which has  been consumed for reacting with water.  the amount of polyurethane hardener precursors and pos› sible epoxy hardener precursor, polyurethane resin,  possible epoxy resin, free water, ketones, propellant  and possible organic solvent, possible pigments is at  least 95% w/w from the total volume of the paint  forming solution and the rest of said solution composes  of the paint additives and dispersion additives.  Polyurethane  and epoxy  hardeners  Weak  acid  ketone  ~  Polyurethane  and epoxy  hardener  precursor  (2a; 2a2)  H20  (free  water)  Polyurethane  hardener  +  ketone  Weak  acid  (catalyst)  Polyurethane  hardener  precursor  (2a; 2al)  H20  +  (free  water)  or  Polyurethane  hardener  Weak  acid  ketone  ~  Polyurethane  and epoxy  hardener  precursors  hardener  precursors  (2a; 2a2)  H20  (free ;  water) 