Patent Publication Number: US-4322324-A

Title: Ampho-ionic group-containing alkyd resins

Description:
This invention relates to novel alkyd resins containing ampho-ionic groups which are suitable for the preparation of solvent type coating compositions. 
     It has been known that ampho-ionic compounds exhibit unique physical and chemical properties. Usually they are not compatible with solvent type coating compositions. 
     It has now been found that certain types of ampho-ionic compounds may be incorporated into alkyd resins as reaction components to give ampho-ionic group-containing alkyd resins suitable for the preparation of solvent type protective coating compositions. The resulting resins exhibit excellent properties as compared with corresponding resins free from such groups e.g. in viscosity and pigment dispersing characteristics. 
     In accordance with the present invention, an alkyd resin containing ampho-ionic groups of the formula: ##STR3## wherein A is a C 1  -C 6  alkylene or a phenylene group, is provided. Said resin comprises, as the reaction components, (a) a polyol, (b) a polybasic carboxylic acid, and (c) an ampho-ionic compound of the formula: ##STR4## wherein A is as defined above, R 1  is a C 1  -C 20  alkyl group containing at least one hydroxyl group, R 2  and R 3  are the same or different and each is a hydrogen atom, a C 1  -C 20  alkyl group optionally containing at least one sulfo and/or hydroxy group. Other components such as oxirane ring-containing compounds or oil modifiers may be incorporated. The resins may be used as the vehicles of solvent type coating compositions either alone or in combination with an aminoplast such as melamine, guanamine or urea resins. 
     As is well-known, alkyd resins comprise, as the essential components, a polyol and a polybasic carboxylic acid for oil-free type, and an oil modifier in addition to said polyol and said polycarboxylic acid for oil modified type. 
     Other modified alkyd resins such as rosin modified, phenol modified, epoxy modified, vinyl modified, isocyanate modified, silicone modified, etc. are also known. The term &#34;alkyd resin&#34; used herein includes all of these types. 
     The alkyd resins of this invention may be prepared by reacting conventional alkyl resin-components in the presence of an ampho-ionic compound of the formula I in accordance with conventional methods which are well-known in the art such as those described in D. H. Solomon, &#34;The Chemistry of Organic Film Formers&#34;, pages 75-87, John Wiley &amp; Sons (1967). 
     The polyols which may be used in the present invention include, for example, ethylene glycol, propylene glycol, 1,3-butylene glycol, 1,6-hexanediol, diethylene glycol, dipropylene glycol, neopentyl glycol, triethylene glycol, 2,2-dimethyl-3-hydroxypropyl 2,2-dimethyl-3-hydroxypropionate, hydrogenated bisphenol A, bisphenol A dihydroxypropyl ether, glycerine, trimethylolethane, trimethylolpropane, tris-(hydroxymethyl)aminomethane, pentaerythritol and mixtures thereof. The amount of polyol reactants may vary from 2 to 90% by weight based on the total weight of the reaction components. 
     Representative examples of the polybasic acids which may be employed include phthalic anhydride, isophthalic acid, terephthalic acid, succinic anhydride, adipic acid, azelaic acid, sebacic acid, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, tetrabromophthalic anhydride, tetrachlorophthalic anhydride, Chlorendic anhydride, Nadic anhydride, maleic anhydride, fumaric acid, itaconic acid, trimellitic anhydride, methylcycloxenetricarboxylic anhydride, pyromellitic anhydride and mixtures thereof. The amount of polybasic carboxylic acid components may vary from 2 to 90% by weight based on the total weight of the reaction components. 
     Representative examples of oil modifiers which may be employed in the oil modified compositions of the present invention include castor oil, coconut oil, linseed oil, palm oil, safflower oil, soybean oil, tung oil, dehydrated castor oil, tall oil, fatty acid derived from these oils, long chain synthetic fatty acids and the like. The amount of oil modifiers may vary from 1 to 80% by weight based on the total weight of the reaction components. 
     Examples of oxirane ring-containing compound which may be employed in the present invention include α-olefine oxides; glycidyl ethers such as phenyl glycidyl ether, methyl glycidyl ether and the like; and glycidyl esters such as versatic acid glycidyl ester and the like. The amount of these components may be less than 90% by weight based on the total weight of the reaction components. 
     To form the ampho-ionic group-containing alkyd resins of the present invention, the reaction components as described above which are conventionally used for the preparation of alkyd resins are reacted in the presence of an ampho-ionic compound of the formula I. Examples of the ampho-ionic compounds which may be employed for this purpose include N-(2-hydroxyethyl)aminomethanesulfonic acid, N- and N,N-di-alkyl e.g. methyl, ethyl, isopropyl, 2-ethylhexyl, decyl, stearyl derivatives thereof; N-(2-hydroxy-1-methylethyl)aminomethanesulfonic acid, N- and N,N-di-alkyl derivatives thereof; N-(3-hydroxypropyl)aminomethanesulfonic acid, N- and N,N-di-alkyl derivatives thereof; N-(2-propyl-2-hydroxyethyl)aminomethanesulfonic acid, N- and N,N-di-alkyl derivatives thereof; N-(2-methyl-2-ethyl-2-hydroxyethyl)aminomethanesulfonic acid, N- or N,N-di-alkyl derivatives thereof; N-(1,2-dimethyl-2-hydroxyethyl)aminomethanesulfonic acid, N- or N,N-di-alkyl derivatives thereof; N-(1,1,2,2-tetramethyl-2-hydroxyethyl)aminomethanesulfonic acid, N- and N,N-di-alkyl derivatives thereof; N-(1,5,5-trimethyl-5-hydroxypentyl)aminomethanesulfonic acid, N- and N,N-di-alkyl derivatives thereof; N-(1,2-diisopropyl-2-hydroxyethyl)aminomethanesulfonic acid, N- and N,N-di-alkyl derivatives thereof; N-(2,3-dihydroxypropyl)aminomethanesulfonic acid, N- and N,N-dialkyl derivatives thereof; N-(1-hydroxymethyl-2-hydroxyethyl)aminomethanesulfonic acid, N- and N,N-di-alkyl derivatives thereof; N-(1-hydroxymethyl-2-hydroxypropyl)aminomethanesulfonic acid, N- and N,N-di-alkyl derivatives thereof; N-(1-hydroxymethyl-3-hydroxypropyl)aminomethanesulfonic acid, N- and N,N-di-alkyl derivatives thereof; N-(1-hydroxymethyl-4-hydroxybutyl)aminomethanesulfonic acid, N- and N,N-di-alkyl derivatives thereof; N-{1,1-bis(hydroxymethyl)-2-hydroxyethyl}-aminomethanesulfonic acid, N- and N,N-di-alkyl derivatives thereof; N-{2,2-bis(hydroxymethyl)-3-hydroxypropyl}aminomethanesulfonic acid, N- and N,N-di-alkyl derivatives thereof; N,N-bis-(2-hydroxyethyl)aminomethanesulfonic acid and N-alkyl derivatives thereof; N-2-hydroxyethyl-N-2-hydroxypropylaminomethanesulfonic acid and N-alkyl derivatives thereof; N,N-bis(2-hydroxypropyl)aminomethanesulfonic acid and N-alkyl derivatives thereof; N,N-bis(4-hydroxybutyl)aminomethanesulfonic acid and N-alkyl derivatives thereof; N-2-hydroxyethyl-N-{1,1-bis(hydroxymethyl)-2-hydroxyethyl}aminomethanesulfonic acid and N-alkyl derivatives thereof; N-3-hydroxypropyl-N-{1,1-bis(hydroxymethyl)-2-hydroxyethyl}aminomethanesulfonic acid and N-alkyl derivatives thereof; N,N-bis(2,3-dihydroxypropyl)aminomethanesulfonic acid and N-alkyl derivatives thereof; N,N-bis(1-hydroxymethyl-2-hydroxyethyl)aminomethanesulfonic acid and N-alkyl derivatives thereof; N,N-bis{1,1-bis(hydroxymethyl)-2-hydroxyethyl}aminomethanesulfonic acid and N-alkyl derivatives thereof; N,N,N-tris(2-hydroxyethyl)ammoniomethane sulfonic acid betaine; N,N-bis(2-hydroxyethyl)-N-3-hydroxypropylammoniomethanesulfonic acid betaine; N,N,N-tris(3-hydroxypropyl)ammoniomethanesulfonic acid betaine; N-(2-hydroxyethyl)aminoethanesulfonic acid, N- and N,N-dialkyl derivatives thereof; N-(2-hydroxy-1-methylethyl)aminoethanesulfonic acid, N- and N,N-di-alkyl derivatives thereof; N-(2-hydroxypropyl)aminoethanesulfonic acid, N- and N,N-di-alkyl derivatives thereof; N-(3-hydroxypropyl)aminoethanesulfonic acid, N- and N,N-di-alkyl derivatives thereof; N-(2-hydroxypentyl)aminoethanesulfonic acid, N- and N,N-di-alkyl derivatives thereof; N-(2-hydroxy-2-methylbutyl)aminoethanesulfonic acid, N- and N,N-di-alkyl derivatives thereof; N-(2-hydroxy-1-methylpropyl)aminoethanesulfonic acid, N- and N,N-di-alkyl derivatives thereof; N-(1,1,2,2-tetramethyl-2-hydroxyethyl)aminoethanesulfonic acid, N- and N,N-di-alkyl derivatives thereof; N-(1,5-dimethyl-5-hydroxypentyl)aminoethanesulfonic acid, N- and N,N-di-alkyl derivatives thereof; N-(1,2-diisopropyl-2-hydroxyethyl)aminoethanesulfonic acid, N- and N,N-di-alkyl derivatives thereof; N-(2,3-dihydroxypropyl)aminoethanesulfonic acid, N- and N,N-di-alkyl derivatives thereof; N-(1-hydroxymethyl-2-hydroxyethyl)aminoethanesulfonic acid, N- and N,N-dialkyl derivatives thereof; N-(1-hydroxymethyl-2-hydroxypropyl)aminoethanesulfonic acid, N- and N,N-di-alkyl derivatives thereof; N-(1-hydroxymethyl-3-hydroxypropyl)aminoethanesulfonic acid, N- and N,N-di-alkyl derivatives thereof; N-(1-hydroxymethyl-4-hydroxybutyl)aminoethanesulfonic acid, N- and N,N-di-alkyl derivatives thereof; N-{1,1-bis(hydroxymethyl)-2-hydroxyethyl}aminoethanesulfonic acid, N- and N,N-di-alkyl derivatives thereof; N-{2,2-bis(hydroxymethyl)-3-hydroxypropyl}aminoethanesulfonic acid, N- and N,N-di-alkyl derivatives thereof; N,N-bis(2-hydroxyethyl)aminoethanesulfonic acid and N-alkyl derivatives thereof; N-(2-hydroxyethyl)-N-(2-hydroxypropyl)aminoethanesulfonic acid and N-alkyl derivatives thereof; N,N-bis(2-hydroxypropyl)aminoethanesulfonic acid and N-alkyl derivatives thereof; N,N-bis(4-hydroxybutyl)aminoethanesulfonic acid and N-alkyl derivatives thereof; N-(2-hydroxyethyl)-N-{1,1-bis(hydroxyethyl)-2-hydroxyethyl}aminoethanesulfonic acid and N-alkyl derivatives thereof; N-(3-hydroxypropyl)-N-{1,1-bis(hydroxymethyl)2-hydroxyethyl}aminoethanesulfonic acid and N-alkyl derivatives thereof; N,N-bis(2,3-dihydroxypropyl)aminoethanesulfonic acid and N-alkyl derivatives thereof; N,N-bis(1-hydroxymethyl-2-hydroxyethyl)aminoethanesulfonic acid and N-alkyl derivatives thereof; N,N-bis{1,1-bis(hydroxymethyl)-2-hydroxyethyl}aminoethanesulfonic acid and N-alkyl derivative thereof; N,N,N-tris(2-hydroxyethyl)ammonioethanesulfonic acid betaine; N,N-bis(2-hydroxyethyl)-N-(3-hydroxypropyl)ammonioethanesulfonic acid betaine; N,N,N-tris(3-hydroxypropyl)ammonioethanesulfonic acid betaine; 3-N-(2-hydroxypropyl)aminopropanesulfonic acid, N- and N,N-di-alkyl derivatives thereof; 3-N-(1-hydroxymethylethyl)aminopropanesulfonic acid, N- and N,N-di-alkyl derivatives thereof; 3-N-(2-hydroxypropyl)aminopropanesulfonic acid, N- and N,N-di-alkyl derivatives thereof; 3-N-(3-hydroxypropyl)aminopropanesulfonic acid, N- and N,N-di-alkyl derivatives thereof; 3-N-(2-hydroxypentyl)aminopropanesulfonic acid, N- and N,N-di-alkyl derivatives thereof; 3-N-(2-hydroxy-2-methylbutyl)aminopropanesulfonic acid, N- and N,N-di-alkyl derivatives thereof; 3-N-(2-hydroxy-1-methylpropyl)aminopropanesulfonic acid, N- and N,N-di-alkyl derivatives thereof; 3-N-(1,1,2-trimethyl-2-hydroxypropyl)aminopropanesulfonic acid, N- and N,N-di-alkyl derivatives thereof; 3-N-(1,5-dimethyl-5-hydroxyhexyl)aminopropanesulfonic acid, N- and N,N-di-alkyl derivatives thereof; 3-N-(1,2-diisopropyl-2-hydroxyethyl)aminopropanesulfonic acid, N- and N,N-di-alkyl derivatives thereof; 3-N-(2,3-dihydroxypropyl)aminopropanesulfonic acid, N- and N,N-di-alkyl derivatives thereof; 3-N-(1-hydroxymethyl-2-hydroxyethyl)aminopropanesulfonic acid, N- and N,N-di-alkyl derivatives thereof; 3-N-(1-hydroxymethyl-2-hydroxypropyl)aminopropanesulfonic acid, N- and N,N-di-alkyl derivatives thereof; 3-N-(1-hydroxymethyl-3-hydroxypropyl)aminopropanesulfonic acid, N- and N,N-di-alkyl derivatives thereof; 3-(1-hydroxymethyl-4-hydroxybutyl)aminopropanesulfonic acid, N- and N,N-di-alkyl derivatives thereof; 3-N-{1,1-bis(hydroxymethyl)-2-hydroxyethyl}aminopropanesulfonic acid, N- and N,N-di-alkyl derivatives thereof; 3-N-{2,2-bis(hydroxymethyl)-3-hydroxypropyl}aminopropanesulfonic acid, N- and N,N-di-alkyl derivatives thereof; 3-{N,N-bis(2-hydroxyethyl)amino}propanesulfonic acid and N-alkyl derivatives thereof; 3-{N-(2-hydroxyethyl)-N-(2-hydroxypropyl)amino}propanesulfonic acid and N-alkyl derivatives thereof; 3-{N,N-bis(2-hydroxypropyl)amino}propanesulfonic acid and N-alkyl derivatives thereof; 3-{N,N-bis(4-hydroxybutyl)amino}propanesulfonic acid and N-alkyl derivatives thereof; 3-{N-(2-hydroxyethyl)-N-(1,1-bis-hydroxymethyl-2-hydroxyethyl)amino}propanesulfonic acid and N-alkyl derivatives thereof; 3-{N,N-bis(2,3-dihydroxypropyl)amino}propanesulfonic acid and N-alkyl derivatives thereof; 3-{N,N-bis(1-hydroxymethyl-2-hydroxyethyl)amino}propanesulfonic acid and N-alkyl derivatives thereof; 3-{N,N-bis(1,1-bis-hydroxymethyl-2-hydroxyethyl)amino}propanesulfonic acid and N-alkyl derivatives thereof; 3-{N,N,N-tris(2-hydroxyethyl)ammonio}propane sulfonic acid betaine; 3-{N,N-bis(2-hydroxypropyl)-N-(3-hydroxypropyl)ammonio}propanesulfonic acid betaine; 3-{N,N,N-tris(3-hydroxypropyl)ammonio}propanesulfonic acid betaine; 5-(N-2-hydroxyethylamino)pentanesulfonic acid, N- and N,N-di-alkyl derivatives thereof; 5-{N,N-bis(2-hydroxyethyl)amino}pentanesulfonic acid and N-alkyl derivatives thereof; 5-{N,N,N-tris(2-hydroxyethyl)ammonio}pentanesulfonic acid betaine; 2-hydroxyethylamine-N,N-bis(ethanesulfonic acid); 2-hydroxypropylamine-N,N-bis-(ethanesulfonic acid); 2,3-dihydroxypropylamine-N,N-bis(ethanesulfonic acid); 1,1-bis(hydroxymethyl)-2-hydroxyethylamine-N,N-bis(ethanesulfonic acid); N-(2-hydroxyethyl)-N-(2-sulfoethyl)aminopropanesulfonic acid; N-(2-hydroxypropyl)-N-(2-sulfoethyl)aminopropanesulfonic acid; N-(2,3-dihydroxypropyl)-N-(2-sulfoethyl)aminopropanesulfonic acid; N-{1,1-bis(hydroxymethyl)-2-hydroxyethyl}-N-(2-sulfoethyl)aminopropanesulfonic acid; N-(2-hydroxyethyl)orthanilic acid; N-(2-hydroxyethyl)methanilic acid; N-(2-hydroxyethyl)sulfanilic acid; N,N-bis(2-hydroxyethyl)orthanilic acid; N,N-bis(2-hydroxyethyl)metanilic acid; N,N-bis(2-hydroxyethyl)sulfanilic acid and the like. Salts of these compounds with alkali metals, ammonia or amines may also be used. The amount of these compounds may vary from 0.05 to 30% by weight, preferably from 0.1 to 20% by weight based on the total weight of the reaction components. 
     The alkyd resin compositions containing the above ampho-ionic component are useful as vehicles of solvent type coating compositions. In most instances, the coating composition contains, in addition to the resin composition and a solvent, a pigment composition (colorant, extender and rust preventive) and various additives such as fillers, thickening agents, surface conditioners, dryers and the like known in the art. The coating compositions may be applied by conventional coating techniques to a desired thickness and dried at room temperature or cured by baking. 
     The alkyd resin compositions of this invention are well compatible with other resinous compositions. 
     Thermosetting coating compositions may be produced by admixing 5 to 100 parts, preferably 7 to 90 parts by weight of an aminoplast such as melamine, guanamine or urea resins with 100 parts by weight of the alkyd resin composition of this invention. The ampho-ionic groups present in the alkyd resin are not only combined with the aminoplast through cross-linking reaction, but also catalytically promote the cross-linking reaction between carboxyl and hydroxyl groups present in the alkyd resin with the aminoplast. Consequently, the thermosetting compositions may be cured under milder conditions than those required for corresponding compositions free from said ampho-ionic groups. Typically the coating may be cured at a temperature from 70° to 220° C. for 0.5 to 120 minutes. 
     The alkyd resin compositions containing ampho-ionic groups have excellent pigment-dispersion properties. Accordingly, it is often advantageous to prepare a pigment paste from a portion of the alkyd resin and then mix the remaining portions and other ingredients with the pigment paste. 
    
    
     The following examples will further illustrate the present invention. All parts and percentages in the examples are by weight unless otherwise specified. 
     EXAMPLE 1 
     A two liter flask provided with stirring means, decanting means, temperature-controlling means, a reflux condenser and nitrogen gas-introducing means was charged with 191 parts of N-2-hydroxyethyltaurine, 140 parts of ethylene glycol, 170 parts of triethylene glycol, 331 parts of adipic acid, 168 parts of phthalic anhydride and 40 parts of xylene. The mixture was heated to boiling. Water formed as a by-product was continuously removed by azeotropic distillation with xylene. The temperature was elevated to 190° C. requiring for about 2 hours from the beginning of distillation. The reaction was continued under stirring and refluxing until the acid number corresponding to carboxylic acid component was less than 10. 
     The resultant oil-free polyester had an acid number of 79, a hydroxyl value of 79 and an average molecular weight (Mn) of 708. 
     EXAMPLE 2 
     A flask as used in Example 1 was charged with 139 parts of N-2-hydroxyethyltaurine, 110 parts of trimethylolpropane, 121 parts of phthalic anhydride, 308 parts of azelaic acid and 27 parts of xylene. The mixture was heated to boiling. Water formed as a by-product was continuously removed by azeotropic distillation with xylene. The temperature was elevated to 190° C. requiring for about 2 hours from the beginning of distillation. The reaction was continued under stirring and refluxing until the acid number corresponding to carboxylic acid component was 145. 
     After cooling the mixture to 140° C., 392 parts of AOE-X24 (α-olefin oxide sold by Daicel Ltd.) were added dropwise for 30 minutes and the mixture was stirred at said temperature for 2 hours. 
     The resultant oil-free polyester had an acid number of 57, hydroxyl value of 150 and an average molecular weight (Mn) of 1040. 
     EXAMPLES 3 to 9 
     Following the procedure as described in Example 1 or Example 2, oil-free polyesters were produced by reacting respective components as shown in Table 1. The properties of the resultant resins are also shown in Table 1. 
     The polyester resins produced in Example 1 through Example 9 were tested on their solubilities in various solvent by adding one part of the resin into 9 parts of a solvent in a test tube, heating to a temperature from 50° to 80° C. and cooling to 25° C. The results are shown in Table 1, wherein symbols have the following meanings: 
     O=dissolving homogeneously 
     Δ=slightly turbid 
     ×=phase separation or intensively turbid 
     
                                           TABLE 1                                 
__________________________________________________________________________
          EX. 1  EX. 2  EX. 3   EX. 4  EX. 5  EX. 6                       
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components (parts)                                                        
          HET 191                                                         
                 HET 139                                                  
                        BHET 191                                          
                                BHET                                      
                                    134                                   
                                       BHET                               
                                           196                            
                                              TES 123                     
          EG  140                                                         
                 TMP 110                                                  
                        1,6-HDO                                           
                             211                                          
                                NPG 130                                   
                                       AZA 345                            
                                              NPG 167                     
          TEG 170                                                         
                 PAn 121                                                  
                        EG    56                                          
                                AZA 236                                   
                                       CaE.sub.10                         
                                           459                            
                                              EG   67                     
          ADA 331                                                         
                 AZA 308                                                  
                        SBA  542                                          
                                PAn 186       ADA 235                     
                 AOE                                                      
          PAn 168                                                         
                 -X24                                                     
                     322        CaE.sub.10                                
                                    314       AZA 303                     
                                              AOE                         
                                              -X24                        
                                                  105                     
acid number                                                               
          79      57     69     59      88     50                         
OH value  79     105    125     90     141    117                         
 ##STR5##  708    1040   807     1054   720    1125                       
water     X      X      X       X      X      X                           
methanol  O      Δ                                                  
                        O       O      O      Δ                     
n-butanol Δ                                                         
                 Δ                                                  
                        Δ O      Δ                            
                                              Δ                     
methylcellosolve                                                          
          O      O      O       O      O      O                           
cellosolveacetate                                                         
          O      O      O       O      Δ                            
                                              O                           
n-butyl acetate                                                           
          Δ                                                         
                 O      Δ O      X      O                           
MIBK      X      O      Δ O      X      O                           
xylene    X      O      Δ O      X      O                           
__________________________________________________________________________
                 EX. 7  EX. 8   EX. 9  Ampho-ionic compound               
__________________________________________________________________________
       components (parts)                                                 
                 HDES                                                     
                     174                                                  
                        HDES 211                                          
                                HCES                                      
                                    340                                   
                                       OES    HCES                        
                 EG   78                                                  
                        NPG  158                                          
                                NPG  94                                   
                 NPG 131                                                  
                        TMAn 146                                          
                                AZA 340                                   
                 ADA 367                                                  
                        AZA  340                                          
                                CaE.sub.10                                
                                    226                                   
                 PAn  93                                                  
                        CaE.sub.10                                        
                             226                                          
                 CaE.sub.10                                               
                     157                                                  
       acid number                                                        
                 102    106     62     237    154                         
       OH value  102    106     62            154                         
        ##STR6## 1348   919     908    237    365                         
       water     X      X       X      O      X                           
       methanol  Δ                                                  
                        O       O      X      X                           
       n-butanol Δ                                                  
                        O       Δ                                   
                                       X      X                           
       methylcellosolve                                                   
                 O      O       O      X      X                           
       cellosolveacetate                                                  
                 O      O       Δ                                   
                                       X      X                           
       n-butyl acetate                                                    
                 O      O       Δ                                   
                                       X      X                           
       MIBK      O      Δ X      X      X                           
       xylene    O      Δ X      X      X                           
__________________________________________________________________________
 
    
     Abbreviations in Table 1 have the following meanings: 
     Ampho-ionic compounds 
     HET=N-2-hydroxyethyltaurine 
     BHET=N,N-bis(2-hydroxyethyl)taurine 
     TES=N-tris(hydroxymethyl)methyltaurine 
     HDES=2-hydroxyethylamine-N,N-bis(ethanesulfonic acid) 
     HCES=N-β-hydroxycetyltaurine 
     OES=N-octyltaurine 
     Polybasic acids 
     ADA=adipic acid 
     PAn=phthalic anhydride 
     AZA=azelaic acid 
     SBA=sebacic acid 
     TMAn=trimellitic anhydride 
     Polyols 
     EG=ethylene glycol 
     TEG=triethylene glycol 
     TMP=trimethylolpropane 
     1,6-HDO=1,6-hexanediol 
     NPG=neopentyl glycol 
     Oxirane compounds 
     CaE 10  =glycidyl ester of versatic acid commercial available from Shell Chemical Company as CARDURA E10 
     AOE-X24=α-olefin oxide commercially available from Daicel Ltd. as AOE-X24 
     BGE=butyl glycidyl ether commercially available from Nippon Oil &amp; Fats Co., Ltd as NISSAN EPIOL-B 
     The polyester resins produced in Examples 4 and 7 were tested on their compatibilities with conventional solvent type resin compositions by mixing 1 part of the resin of this invention with 1 part of a coconut oil modified alkyl resin (BEGKOSOL 1323, oil length 32%), or an oil-free alkyd resin (BECKOLITE M6402-50), or a butylated melamine resin (SUPER BECKAMINE J820-60), all commercially available from Dainippon Ink and Chemicals, Ltd. The results are shown in Table 2, wherein symbols have the following meanings: 
     ○=dissolving homogeneously 
     Δ=slightly turbid 
     ×=phase separation or intensively turbid 
     
                       TABLE 2                                                     
______________________________________                                    
                        Ampho-ionic                                       
                        compound                                          
                EX. 4 EX. 7   OES    HCES                                 
______________________________________                                    
BECKOSOL 1323     O       Δ X    X                                  
BECKOLITE M6402-50                                                        
                  O       O       X    X                                  
SUPER BECKAMINE J820-60                                                   
                  O       O       X    X                                  
______________________________________                                    
 
    
     EXAMPLE 10 
     1st stage 
     A flask as used in Example 1 was charged with 994 parts of linseed oil, 183 parts of pentaerythritol and 15  parts lead naphthenate. The mixture was stirred at 240° C. under nitrogen gas current for 30 minutes whereupon methanol tolerance was infinite. 
     2nd stage 
     The inner temperature was allowed to fall to 150° C. without stirring. To the reaction mixture were added 321 parts of phthalic anhydride, 5,5 parts of N,N-bis(2-hydroxyethyl)aminoethanesulfonic acid and 45 parts of xylene. The mixture was heated again with stirring. Water formed as a by-product was continuously removed by azeotropic distillation with xylene. The temperature was elevated in 240° C. requiring for about 2 hours. The reaction was continued under stirring and refluxing at said temperature until the acid number corresponding to carboxylic acid component was 8. The resultant resin had an oil length of 65, an acid number of 8.5, a hydroxyl value of 50 and an average molecular weight (Mn) of 1800. 
     This resin was diluted with xylene to a nonvolatile content of 70%. The resultant alkyd varnish had a viscosity of Z when measured Gardener viscometer. 
     EXAMPLES 11 TO 18 
     Following the procedure as described in Example 10, similar alkyd resins were produced by reacting respective components as shown in Table 3. The properties of the resins are also shown in Table 3. 
     
                                           TABLE 3                                 
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                                                     CON- CON-            
                                                     TROL TROL            
             EX. 11                                                       
                  EX. 12                                                  
                       EX. 13                                             
                            EX. 14                                        
                                 EX. 15                                   
                                      EX. 16                              
                                           EX. 17                         
                                                EX. 18                    
                                                     1    2               
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components                                                                
      SO     676  --   --   --   --   --   --   --   --   --              
1st stage                                                                 
      DCO    --   260  85   85   85   --   260  85   --   260             
(parts)                                                                   
      CO     --   192  63   63   63   --   193  63   --   192             
      LO     --   --   --   --   --   994  --   --   994  --              
      PE     208  --   --   --   --   169  166  --   183  --              
      TMP    --   160  50   50   53   --   --   53   --   160             
      ampho-ionic                                                         
             --   --   (3) 6                                              
                            (4) 7                                         
                                 --   (6) 30                              
                                           --   --   --   --              
components                                                                
      PAn    527  578  --   765  767  --   554  725  321  578             
2nd stage                                                                 
      IPA    --   --   753  --   --   --   --   --   --   --              
(parts)                                                                   
      ADA    --   --   --   --   --   316  --   --   --   --              
      EG     74   --   --   --   --   2    --   --   --   --              
      DEG    --   59   278  --   53   --   320  343  --   65              
      TMP    --   243  276  441  455  --   --   43   --   243             
      ampho-ionic                                                         
      compound                                                            
             (1) 50                                                       
                  (2) 15                                                  
                       --   (2) 197                                       
                                 (5) 75                                   
                                      --   (2) 10                         
                                                (2) 375                   
                                                     --   --              
alkyd resin                                                               
      oil length                                                          
             45   30   10   10   10   65   30   10   65   10              
properties                                                                
      acid number                                                         
             16.5 10.5 8.5  4.1  16   12   9.5  6.6  8.5  8.5             
      OH value                                                            
             80   100  100  100  100  50   100  100  50   100             
       ##STR7##                                                           
              1830                                                        
                   1520                                                   
                        1500                                              
                             4000                                         
                                  5000                                    
                                       1800                               
                                            800  800  1810                
                                                           1500           
varnish                                                                   
      nonvolatile                                                         
             60   60   60   60   60   70   70   60   70   60              
      (%)                                                                 
      viscosity                                                           
             Z    Z    Z    Z.sub.4                                       
                                 Z.sub.4                                  
                                      Y    X    Z.sub.2                   
                                                     Y    Z               
__________________________________________________________________________
 
    
     Abbreviations in Table 3 have the following meanings: 
     SO=soybean oil 
     DCO=dehydrated castor oil 
     CO=coconut oil 
     LO=linseed oil 
     PE=pentaerythritol 
     TMP=trimethylolpropane 
     PAn=phthalic anhydride 
     ADA=adipic acid 
     EG=ethylene glycol 
     DEG=diethylene glycol 
     Ampho-ionic compounds used are as follows: 
     (1) N-(2,3-dihydroxypropyl)aminopropanesulfonic acid 
     (2) N,N-bis(2-hydroxyethyl)aminoethanesulfonic 
     (3) N-{1,1-bis(hydroxymethy)-2-hydroxyethyl}taurine 
     (4) N,N,N-tris(2-hydroxyethyl)ammoniopropanesulfonic acid betaine. 
     (5) N-(2,3-dihydroxypropyl)-N-octylaminotaurine 
     (6) N-3-hydroxypropyl-N-{1,1-bis(hydroxymethyl)-2-hydroxyethyl}aminoethanesulfonic acid 
     EXAMPLE 19 
     A flask as used in Example 1 was charged with 81 parts of dehydrated castor oil, 59 parts of coconut fatty acid, 121 parts of trimethylolpropane, 715 parts of phthalic anhydride, 481 parts of diethylene glycol, 80 parts of N-methyl-N-(1-hydroxymethyl-2-hydroxyethyl)aminomethanesulfonic acid and 45 parts of xylene. The mixture was heated to 240° C. with stirring. Water formed as a by-product was removed by azeotropic distillation with xylene. The reaction was continued until the acid number corresponding to carboxylic acid component was 8. The resultant alkyd resin had an oil length of 10, an acid number of 22.5, a hydroxyl value of 100 and an average molecular weight (Mn) of 800. The resin was diluted with xylene to a nonvolatile content of 60%. 
     The resultant varnish had a Gardener viscosity of Z. 
     EXAMPLES 20 TO 23 
     Following the procedure as described in Example 19, similar alkyd resins were produced by reacting respective components as shown in Table 4. The properties of the resins are also shown in Table 4. 
     
                                           TABLE 4                                 
__________________________________________________________________________
                                 CONTROL                                  
             EX. 20                                                       
                  EX. 21                                                  
                       EX. 22                                             
                            EX. 23                                        
                                 3                                        
__________________________________________________________________________
components                                                                
      DCAFA  243  81   140  243  81                                       
(parts)                                                                   
      CFA    177  59   --   177  59                                       
      TMP    458  478  533  465  478                                      
      PAn    550  751  764  550  751                                      
      DEG    63   --   40   60   131                                      
      ampho-ionic                                                         
             (3) 12                                                       
                  (2) 263                                                 
                       (7) 105                                            
                            (8) 15                                        
                                 --                                       
      compound                                                            
alkyd resin                                                               
      oil length                                                          
             30   10   10   30   10                                       
properties                                                                
      acid number                                                         
             10   50.5 25.5 12   8                                        
      OH value                                                            
             100  100  100  100  100                                      
       ##STR8##                                                           
              1390                                                        
                   2470                                                   
                        2460                                              
                             1200                                         
                                  2470                                    
varnish                                                                   
      nonvolatile                                                         
             60   60   60   60   60                                       
      (%)                                                                 
      viscosity                                                           
             Z    Z.sub.3                                                 
                       Z.sub.2                                            
                            Z    Z                                        
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     Abbreviations have the following meanings: 
     DCOFA=dehydrated cator oil fatty acid 
     CFA=coconut fatty acid 
     Ampho-ionic compounds used are as follows: 
     (7) N,N-dimethyl-N-(2-hydroxyethyl)ammoniopropanesulfonic acid betaine 
     (8) 2-hydroxyethylamine-N,N-bis(ethanesulfonic acid) 
     Other abbreviations and ampho-ionic compounds are the same as in Table 3. 
     EXAMPLE 24 
     158 parts of the alkyd resin varnish produced in Example 11, 8.5 parts of butylated melamine resin varnish commercially available from Dainippon Ink And Chemicals Ltd. as SUPER BECKAMINE G-821-60 and 100 parts of petroleum solvent sold as SOLVESSO were mixed in a labomixer at room temperature. 
     The resulting thermosetting composition was applied onto tinplate pieces to produce dry films of 30μ thickness. The coated pieces were than baked for 20 minutes at 100° C., 120° C., 140° C. or 160° C. respectively. The films were extracted with acetone using soxhlet extractor for 4 hours. Unextracted residues were 68%, 88%, 92% and 96% when baked at 100° C., 120° C., 140° C. and 160° C. respectively. 
     EXAMPLE 25 
     117 parts of the alkyd resin varnish of Example 12, 50 parts of SUPER BECKAMINE G-821-60 and 100 parts of SOLVESSO were mixed as in Example 24. The resulting composition was applied onto a tinplate piece to produce a dry film of 40μ thickness which gave, when baked at 140° C. for 20 minutes, a transparent coating having pencil hardness of H and a cross-linking density of 2.08×10 -3  mol/cm 3 . 
     For comparison, the above procedure was repeated except that the alkyd resin varnish of Control 2 in Table 3 was replaced for that of Example 12. The resulting transparent coating had pencil hardness of HB and a cross-linking density of 1.22×10 -3  mol/cm 3 . 
     EXAMPLE 26 
     The procedure of Example 24 was repeated except that 133 parts of each varnish of Examples 13 to 15 and 18 to 23 or 114 parts of the varnish of Example 17 were mixed with 33 parts of SUPER BECKAMINE G-821-60. All of the films, when baked at 120° C. for 20 minutes, gave transparent coatings which exhibited unextracted residues of greater than 87% upon the acetone extraction test. 
     EXAMPLES 27 AND 28 
     50 parts of each varnish produced in Example 10 and 16 and Control 1 were thoroughly mixed with 27 parts of titanium dioxide pigment, 10 parts of calcium carbonate pigment, 0.3 parts of lead naphthenate and 8 parts of aliphatic hydrocarbon solvent in a paint conditioner for 30 minutes. The resulting coating compositions were applied onto steel plates to produce dry films of 40μ thickness, respectively, and dried at toom temperature. 
     The properties of the coatings are shown in Table 5. 
     
                       TABLE 5                                                     
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                   semi-curing                                            
        tack-free time                                                    
                   time      60° gloss,                            
varnish (min.)     (hrs.)    24 hours                                     
                                    brightness                            
______________________________________                                    
Example 10                                                                
        10         2         93     very good                             
Example 16                                                                
        10         2         93     very good                             
Control 1                                                                 
        15         3         91     good                                  
______________________________________                                    
 
    
     Brightness was observed visually. 
     EXAMPLE 29 
     A pigment paste was produced by mixing 225 parts of the varnish of Example 12, 90 parts of anthraquinone red pigment (CROMOPHTAL RED A3B, (Ciba), 132 parts of xylene and 53 parts of ethylene glycol monobutyl ether for 2 hours in a paint conditioner, and grinding to coarse particle size of 5μ. 
     A thermosetting coating composition was prepared by combining 28 parts of the pigment paste prepared as described above with 28 parts of SUPER BECKAMINE G-821-60 with stirring for 20 minutes. 
     A steel plate which was previously given a middle coating of alkyd-melamine type (OTO-778, Nippon Paint Co., Ltd.) was coated by the above composition to produce a dry film of 40μ thickness, which was, in turn, baked at 140° C. for 20 minutes. 
     For comparison, the above procedure was repeated except that the varnish obtained in Control 2 was replaced for that of Example 12 and the mixing time in paint conditioner was extended to 3 hours. 
     The properties of resultant pigment pastes, coating compositions and cured films are shown in Table 6. 
     
                       TABLE 6                                                     
______________________________________                                    
                  varnish                                                 
                  Example 12                                              
                          Control 2                                       
______________________________________                                    
viscosity *.sup.1  of                                                     
          V.sub.2 (cps)*.sup.2                                            
                        1.2 × 10.sup.5                              
                                  3.9 × 10.sup.5                    
pigment paste                                                             
          V.sub.20 (cps)*.sup.3                                           
                        3.0 × 10.sup.4                              
                                  5.1 × 10.sup.4                    
          TI*.sup.4     4         7.6                                     
viscosity*.sup. 1 of                                                      
          V.sub.2 (cps) 4.8 × 10.sup.3                              
                                  2.0 × 10.sup.3                    
coating   V.sub.20 (cps)                                                  
                        3.0 × 10.sup.3                              
                                  4.0 × 10.sup.3                    
composition                                                               
          TI            1.6       5                                       
properties of                                                             
          gloss*.sup. 5 100       100                                     
cured film                                                                
          water-resistance*.sup.6                                         
                        no change slight blister                          
          HCl-resistance*.sup.7                                           
                        no change slight                                  
                                  discoloration                           
______________________________________                                    
 *.sup.1 Brookfield viscosity (H type), 25° C.                     
 *.sup.2 Viscosity at 2 r.p.m.                                            
 *.sup.3 Viscosity at 20 r.p.m.                                           
 *.sup.4 V.sub.2 /V.sub.20                                                
 *.sup.5 Measured by 60° gloss meter                               
 *.sup.6 Appearance after dipping in water for 15 days at 40° C.   
 *.sup.7 A hollow glass cylinder was placed on the coated plate.          
 
    
     One ml. of 1 N HCl was dropped into the cylinder and the film was exposed to HCl vapor for 1 hour at 55° C. 
     EXAMPLE 30 
     A pigment paste was produced by mixing 70 parts of the varnish of Example 21 with 47 parts of red perylene pigment (PALIOGEN MAROON 4020, BASF), 69 parts of SOLVESSO and 14 parts of n-butanol for 2 hours in a paint conditioner, and grinding to coarse particle size of 5μ. 
     A thermosetting coating composition was prepared by combining 28 parts of the pigment paste prepared as described above with 40 parts of the varnish of Example 21 and 28 parts of SUPER BECKAMINE G-821-60 with stirring for 20 minutes. 
     A steel plate which was previously given a middle coating of OTO-778 was coated by the above composition to produce a dry film of 40μ thickness, which was, in turn, baked at 140° C. for 20 minutes. 
     For comparison, the above procedure was repeated except that the varnish obtained in Control 3 was replaced for that of Example 21 and the mixing time in paint conditioner was extended to 3 hours. 
     The properties of resultant pigment pastes and cured films are shown in Table 7. 
     
                       TABLE 7                                                     
______________________________________                                    
               varnish                                                    
               Example 21                                                 
                       Control 3                                          
______________________________________                                    
viscosity of                                                              
         V.sub.2 (cps)                                                    
                     50        4.3 × 10.sup.3                       
pigment paste                                                             
         V.sub.20 (cps)                                                   
                     50        0.7 × 10.sup.3                       
         TI           1        6.1                                        
properties of                                                             
         gloss       99        99                                         
cured film                                                                
         water-resistance                                                 
                     no change slight blister                             
         HCl-resistance                                                   
                     no change slight discoloration                       
______________________________________                                    
 
    
     The above has been offered for illustrative purposes only, and it is not for the purpose of limiting the scope of this invention, which is defined in the claims below.