Water-Dilutable Stone Impact Protection Paint and Compensation Paint, Their Use and Process For Their Production

Abstract

This invention relates to a method of coating a motor vehicle body including (i) applying as a first layer an electro-dip primer coat; (ii) mixing a water dilutable compensation paint comprising 40 to 80 wt. % binders and a commercial base coat to obtain a mixture, and applying the mixture as a second primer surface layer on said primer coat wherein the primer surface layer applied has a thickness of from 10 to 20 μm; (iii) applying a third layer consisting of a water soluble base coat; and (iv) applying a covering layer of clear coat.

1 . A method of coating a motor vehicle body comprising:
 (a) applying as a first layer an electro-dip primer coat;   (b) mixing a water dilutable compensation paint comprising 40 to 80 wt. % binders and a commercial base coat to obtain a mixture, and applying the mixture as a second primer surface layer on said primer coat wherein the primer surface layer applied has a thickness of from 10 to 20 μm;   (c) applying a third layer consisting of a water soluble base coat; and   (d) applying a covering layer of clear coat.   
   
   
       2 . A method of coating a motor vehicle body comprising: applying as a first layer an electro-dip primer coat, mixing a water dilutable compensation paint comprising 40 to 80 wt. % binders and a commercial base coat to obtain a mixture, and applying as a second layer a layer of thickness from 10 to 20 μm comprising the mixture, and then applying a covering layer of clear coat onto the second layer. 
   
   
       3 . The method of coating a motor vehicle body of  claim 1 , wherein the water dilutable compensation paint additionally comprises up to 20 wt. % pigments. 
   
   
       4 . The method of coating a motor vehicle body of  claim 3 , wherein the ratio of binders to pigments is from 10:1 to 15:1. 
   
   
       5 . The method of coating a motor vehicle body of  claim 1 , wherein the binder is a water compatible acrylate resin. 
   
   
       6 . The method of coating a motor vehicle body of  claim 1 , wherein said binder is a water compatible blocked isocyanate, a polyurethane, polyester or a melamine resin. 
   
   
       7 . The method of coating a motor vehicle body of  claim 6 , wherein said binder is a polyester resin, said polyester resin has an average molecular weight of from 5,000 to 10,000, exhibits sufficient carboxyl groups which impart to the polyester resin, after neutralization with bases, sufficient water-dilutable characteristics and contains crosslinkable functional groups. 
   
   
       8 . The method of coating a motor vehicle body of  claim 6 , wherein said binder is a polyester resin, said polyester resin has a OH-number of from 20 to 80 and an acid number of from 10 to 50. 
   
   
       9 . The method of coating a motor vehicle body of  claim 6 , wherein said binder is a polyester resin, said polyester resin has a glass transition temperature (Tg) of from −20 to +30° C. 
   
   
       10 . The method of coating a motor vehicle body of  claim 6 , wherein the binder is a polyester resin, said polyester is a polycondensation product of a diol and a dicarboxylic acid in the presence of a component containing more than two functional groups. 
   
   
       11 . The method of coating a motor vehicle of  claim 10 , wherein the diol is selected from the group consisting of 1,6-hexandiol, neopentylglycol, 1,4-dimethylolcyclohexane hydroxypivalic neopentyl glycol ester (HPN), perhydrogenated bisphenol A, trimethylolpropane trimethylolpropane monoallyl ether and mixtures thereof. 
   
   
       12 . The method of coating a motor vehicle body of  claim 10 , wherein the dicarboxylic acid is selected from the group consisting of adipic acid, phthalic acid, isophthalic acid, hexahydrophthalic acid, tetrahydrophtalic acid or their anhydrides, from the group of a dimeric fatty acid and mixtures thereof. 
   
   
       13 . The method of coating a motor vehicle body of  claim 10 , wherein the component containing more than two functional groups is selected from the groups consisting of a triol, a tricarboxylic acid, a monohydroxydicarboxylic acid, a dihydroxymonocarboxolic acid and mixtures thereof. 
   
   
       14 . The method of coating a motor vehicle body of  claim 10 , wherein said component containing more than two functional groups is selected from the group consisting of trimellithic acid, trimethylolpropane, in particular dimethylolpropionic acid and mixtures thereof. 
   
   
       15 . The method of coating a motor vehicle body of  claim 1 , wherein the compensation paint further comprises organic solvents and additives. 
   
   
       16 . The method of coating a motor vehicle body of  claim 2 , wherein the water dilutable compensation paint additionally comprises up to 20 wt. % pigments. 
   
   
       17 . The method of coating a motor vehicle body of  claim 1 , wherein the ratio of binders to pigments is from 10:1 to 15:1. 
   
   
       18 . The method of coating a motor vehicle body of  claim 2 , wherein the binder is a water compatible acrylate resin. 
   
   
       19 . The method of coating a motor vehicle body of  claim 2 , wherein said binder is a water compatible blocked isocyanate, a polyurethane, polyester and/or a melamine resin. 
   
   
       20 . The method of coating a motor vehicle body of  claim 2 , wherein the compensation paint further comprises organic solvents and additives. 
   
   
       21 . A method of coating a motor vehicle body comprising: applying as a first layer an electro-dip primer coat, mixing a water dilutable compensation paint comprising 40 to 80 wt. % binders and a base coat to obtain a mixture, and applying onto the first layer the mixture as a second layer of thickness from 10 to 20 μm, and then applying a covering layer of clear coat onto the second layer.