Ingevity
                            
                           
                           
                            
                          
                           
                           
                          
                             
                           
                            
 
CAPA 4101 is a premium polyester polyol tetrol that is specifically suited to produce high performance polyurethane coatings. CAPA 4101 is part of a full line of premium aliphatic polyester polyols based on polycarpolactone chemistry that can be used for a wide range of polyurethane applications, including coatings, adhesives, sealants and elastomers.

The CAPA range of polycaprolactones are low viscosity, solvent-free polyols that have excellent hydrolysis resistance and excellent mechanical properties. Chemically speaking, CAPA polyols are essentially glycol adipate polyester polyols. However, the manner in which the CAPA polyols are made result in significantly enhanced properties. Specifically, CAPA polycaprolactones are synthesized via an ring opening addition polymerization process, which results in a narrow polydispersity or molecular weight distribution.  The narrow molecular weight distribution is responsible for reduced viscosities and improved mechanical properties (particularly at extreme temperatures). The addition polymerization process eliminates the acid catalysts used to produce conventional polyester polyols, resulting in ultra-low acid values and ehanced  hydrolytic stability.

CAPA 4101 is tetrafunctional (functionality of 4.0), has an OH value of  218 mg KOH/g (6.8% OHV) and an equivalent weight of 250. CAPA 4101's high functionality combined with the low molecular weight distribution and enhanced hydrolytic stability provides a powerful tool in a polyurethane coating formulator's toolbox.
Perstorp CAPA 4101
CAPA 4101
  • Lowers VOC
  • Improves impact resistance.
  • Improves abrasion resistance
  • Improves chemical resistance.

Formulation Approach

Ingevity and TRiiSO suggest starting with a high performance acrylic polyol system, add increasing weight percent of CAPA 4101, and then add required solvent to reach spray viscosity.
 
Starting Point Formulation Example
  Supplier Grind Part
     Parts
SM2810/75  Allnex  35.68
Butyl Acetate    30.50
TiPure R960  Chemours  18.38
Everstab 328  Everspring    0.32
Everstab LS-292  Everspring    0.32
DynoAdd F1  Dynoadd    0.54
Endacat 201 (cut 10% in Butyl Acetate)  TRiiSO    0.54
Incozol 2  Incorez    2.16
Totals    88.44
 
 Let down   Reference 0% 1.54% w/w
CAPA 4101
3.85% w/w
CAPA 4101
7.70% w/w
CAPA 4101 
11.6% w/w
CAPA 4101
  Supplier Parts Parts Parts Parts Parts
Additional 2810/75 Allnex 11.56 10.02 7.71 3.86 0
CAPA 4101 Perstorp 0 1.54 3.85 7.7 11.56
Total Parts Part A   100 100 100 100 100
             
Tolonate HDT LV2  Vencorex 21.8 22.37 23.26 24.72 26.19
NCO/OH   1.05 1.05 1.05 1.05 1.05
Total Weight   121.8 122.37 123.26 124.72 126.19
*Spray viscosity of 100 cps


Formulation Properties

CAPA 4101 has a minimal impact on potlife at lower concentrations, and VOC levels of the final coatings are decreased with the addition of CAPA 4101 as a result of higher solids content.:

CAPA 4101 Impact on Pot LifeTotal Solids Content and VOC Content


 


 






With regards to appearance, CAPA 4101 increases gloss, increases pencil hardness, and reduces Konig hardness.

Gloss on Dry FilmsKonig Hardness










 
                                                          Pencil Hardness  #52 Rod on Un-primed Q-panels
% CAPA 4101  0%  1.54%  3.85%  7.70%  11.50%
Panel A  HB  HB F 2H 3H
Panel B  HB  HB F 2H 3H

(173 gram standard weight applied to stylus with pencil; Tested in duplicate)

Pencil Hardness Scale


CAPA 4101 provides a significant increase in impact resistance with and without primer, even at lower temperatures.  

CAPA 4101and Impact Resistance
CAPA 4101 and Reverse Impact Resistance











Direct Impact at Low TemperatureReverse Impact at Low Temperature











Abrasion resistance is improved with increased concentration of CAPA 4101.

CAPA 4101 and Abrasion Resistance

 
  • CS17 wheels/ 1000 gram weight/ 1000 cycles
  • Panels primed and coated with #52 rod topcoat deposition
  • Sample Panels conditioned 24 hours in dessicator prior to abrasion testing
  • MG loss results recorded immediately after test completion and after 24 hours reconditioning in dessicator
  • Each system run in duplicate



Although the chemical resistance of the initial acrylic polyol formulation was good, the addtion of CAPA 4101 yielded an incremental improvement in performance.  Specifically, a primed panel exposed to 300 MEK double rubs had no impact on gloss for formulations containing 3.85%, 7.70%, and 11.50% CAPA 4101.  The formulation containing 1.54% CAPA 4101 had slight mar with slight degloss and the reference formulation mars with degloss.
 
12 Hour Exposure - Chemical Resistance
  Reference 0%  1.54%
CAPA 4101
3.85%
CAPA 4101
7.70%
CAPA 4101
11.50%
CAPA 4101
Glacial Acetic Acid Destroyed Destroyed Destroyed Destroyed Destroyed
Skydrol LD-4 Slight mark Slight mark Slight mark Slight mark Slight mark
Purell Hand Cleaner No effect No effect No effect No effect No effect
60:40 Gasoline/Toluene mix Slight mark Slight mark Slight mark Slight mark Slight mark
De-icer (MeOH/Ethylene glycol mix) Slight mark No effect No effect No effect No effect
Synthetic Brake Fluid Degloss Slight degloss Slight degloss Slight degloss Slight degloss
Automatic Transmission Fluid No effect No effect No effect No effect No effect
Synthetic Gear Oil (grade ISO 460) Slight Degloss Slight Mark No effect Slight mark Slight mark


Conclusions and Summary:
  • CAPA 4101 is a banched aliphatic polyester polyol
  • Reactive Diluent and Resin Modifier
  • Functionality 4.0
    • Reduces solvent demand
    • Improves impact resistance
    • Improves abrasion resistance
    • Improves chemical resistance
  • TRiiSO and Ingevity recommend starting with a concentration of 2-4% CAPA 4101 to optimize coating properties


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