Back to Basics : An Overview of Surface Coating Chemistry

1. Back to Basics: An Overview of Surface Coating Chemistry October 2002Ó Author / Presenter : George M. Schmitz

2. Surface Coatings Course: • 4 semesters – 15 weeks per semester for two hours each Monday night. • Over 120 hours of classroom training • Field trips to paint companies, testing laboratories, visits to chemical production facilities such as resin manufacturers and pigment dispersion facilities all aimed at improving the overall coatings expertise of our students.

3. Surface Coatings Course: • The presentations have been engineered to make learning fun • Special guest lecturers to make the course rewarding for all levels of skill • Standalone Back to Basics program with practical emphasis on Coating Technology. • Top rated students eager to participate, learn and with a desire to get involved in the coatings industry.

4. Grading • Participation/ attendance 20 % • Homework 30 % • Midterm 15 % • Final 15 % • Technical Assignment 20 %

5. Homework • Given each week 30 % • “Suggested Due date each week” • “Must be submitted by end of term “Cheating is Allowed….”

6. Technical Assignments • Students select their topic of interest • A panel of students “grade” their peers • Each student gives their presentation “Teacher for a day …”

7. Introduction

8. About this semester: Surface Coatings One • Introduction to Basic Surface Chemistry • Terminology and Raw materials • Resin theory including; • epoxies, emulsions, alkyds, silicones, cellulosics, urethanes, acrylics • Pigment chemistries • Solvents and additives will be discussed in detail with emphasis on the “basics”.

9. About this semester: Surface Coatings Two • Trade Sale Paints and Coatings • Raw Materials for Architectural Coatings • Coatings Calculations • Dispersion Process and Equipment • Pigments and Tinting Systems • Color Matching • Formulating Latex and Oils • Special Formulating Know-How • Manufacturing Methods, and Testing and Quality Control Techniques.

10. About this semester: Surface Coatings Three • Industrial Coating formulating, manufacturing and applications. • Surface preparation • Corrosion theory • Automotive Coatings, OEM, Coil Coatings • Powder Coating • Lacquers • Radiation Curing • ISO & TQM – Quality Programs, Environmental Regulations and Statistical Process Control.

11. About this semester: Surface Coatings Four • Emphasis on the Science of Rheology • Pigment Dispersion Theory • Film analysis including Failures and Defects • Surface Tension Theory

12. Surface Coating OneBack to Basics • 1. Introduction • 2. Understanding the Basic Formula Components • 3. Key Properties and their Affect on Performance • 4. Key Coatings Calculations used for Design • 5. Selection of Raw Materials for Starting Points • Polymers for Performance • Pigments for Enhanced Performance • 6. Questions and Answers needed for Coatings Design • Creation of “The Decision Tree”

13. Formulating Tips • Selecting the proper Raw Materials • Understanding their Features, Applications, & Benefits. • Polymers and Pigments that meet Design Criteria. • Designs based on Key Paint Calculations • PVC , P / B , VOC , Coating Weight, Spreading Rates. • FAQ - Frequently Asked Questions

14. “ Understanding Key Terminology ” • Architectural Coating Gloss Meter Measurements Description 60 ° 85 °20 ° I. Flat 0-5 0-15 N/A II. High Sheen Flat 0-10 15 + -- III. Eggshell 10-25 ---- -- IV. Low Semi-gloss 25-40 ---- -- V. Semi (Regular) 40-55 ---- -- VI. High Semi 55-70 ---- -- VII. Gloss (Regular) 70-85 ---- 70-85 VIII. High Gloss 85 + N/A 85 +

15. Formula Design • PVC : Pigment Volume Concentration Description PVC % Titanium % Extender I. Flat 55- 80 % < 5 % 50- 75 % II. High Sheen Flat 50- 55 % 10- 20 % 30- 45 % III. Eggshell (Satin) 45- 50 % 10- 20 % 30- 50 % IV. Low Semi-gloss 35- 45 % 10- 20 % 15- 35 % V. Semi (Regular) 30- 35 % 10- 20 % 10- 25 % VI. High Semi 25- 30 % 10- 20 % 5- 20 % VII. Gloss (Regular) 20- 25 % 10- 20 % 0- 15 % VIII. High Gloss < 25 % < 25 % Negligible

16. Agenda: Design Criteria • 1. Introduction • 2. Understanding the Basic Formula Components • 3. Key Properties and their Affect on Performance • 4. Key Coatings Calculations used for Design • 5. Selection of Raw Materials for Starting Points • Polymers for Performance • Pigments for Enhanced Performance • 6. Questions and Answers needed for Coatings Design • 7. Interactive WEB SITE Design : PaintCAMÓ

17. Surface Coatings: The 4 Basic Components • Binders ( also called Resins or Polymers) * • Pigments ( including extenders) • Solvents • Additives * Vehicle = Binder + Solvent

18. 4 Basic Coatings Components • 1. Polymers for Coating Performance • Durability , Adhesion, block resistance, Chemical & Solvent Resistance, Color. • 2. Pigments for Enhanced Coating Performance • Durability, Gloss, Opacity, Chemical & Solvent Resistance,Color. • 3. Additives for Advantages • Substrate wetting, Rheology, Viscosity • 4. Solvents for Surface Application • Surface Tension control, evaporation rate

19. 4 Basic Coating Components 1. Resins ( Binders ) : As the name “ binder ” implies, it is the glue that holds the coating cohesively ( internally ) together and adhesively ( externally ) to the substrate or intercoats.

20. 4 Basic Coating Components • 1. Resins ( Binders ) : • Most important Performance Component of the Coating. • Determines Chemical & Physical Properties of Paint. • Basis of Protection capability. • Determines / demands specific application Methods. • Responsible to wet ( dispersion ) and protect formulated pigments.

21. 4 Basic Coating Components 2. Pigments : Finely ground, natural or synthetic, inorganic ( Titanium Dioxide ) or organic ( Phthalocyanine Blue ) INSOLUBLE dispersed particles which, when dispersed in a liquid vehicle may provide color, opacity, durability, corrosion resistance or enhance other essential protective or aesthetic properties of the coating.

22. 4 Basic Coating Components • 2. Pigments : • Determine degree of Hiding ( Opacity / Transparency). • Control gloss, surface characteristics. • Influence flow & leveling or application properties ( Rheology ). • Used for special finish color effects ( metallic, pearl, colored ). • Color aesthetics. • Affect light fastness (colored), corrosion inhibition (functional).

23. 4 Basic Coating Components 3. Solvents : Liquid, usually volatile , which is used in the manufacture of paint to dissolve or disperse the film forming constituents, and which EVAPORATES during drying and therefore does not become a part of the dried film.

24. 4 Basic Coating Components • 3. Solvents : • Regulates Application Properties. • Controls consistency and character of the finish ( minimizes defects ). • Controls evaporation rate. • Adjusts and influences coating viscosity ( thickness of paint ). • Adjusts solids level which influences film application thickness. • Used in resin manufacturing (synthesis ) / handling.

25. 4 Basic Coating Components 4. Additives : Any substance added in small quantities to a coating to modify and improve performance ( usually less than 10 %; 0.5 - 1% more common ).

26. 4 Basic Coating Components • 4. Additives : • I. In Production, • Controls foaming, surface tensions. • Assists with pigment incorporation. • II. In storage, • Prevents paint skinning, settling of pigments. • Controls bacteria growth, freeze thaw resistance, package stability. • III. In application, • Controls paint sagging/ flow control, edge control. • Influences Curing rate ( release agents ) , catalysis, drying. ( driers ). • Influences gloss , coalescing, substrate wetting. • IV. In cured films, • Improves mar resistance ( Waxes ). • Prevents mold / fungus growth.

27. Agenda: Design Criteria • 1. Introduction • 2. Understanding the Basic Formula Components • 3. Key Properties & their Affect on Performance • 4. Key Coatings Calculations used for Design • 5. Questions and Answers needed for Coatings Design • 6. Selection of Raw Materials for Starting Points • Polymers for Performance • Pigments for Enhanced Performance

28. Basic Coating Film Properties • Physical Properties • Permeability Properties • Optical Properties

29. Basic Coating Film Properties • Physical Properties • Density • Tensile Strength • Adhesion • Mar resistance • Abrasion resistance

30. Basic Coating Film Properties • Permeability Properties • Film porosity • Rusting • Blistering • Wet Adhesion resistance • Staining • Enamel holdout

31. Basic Coating Film Properties • Optical Properties • light scattering • Contrast ratio • Tinting strength • Hiding Power Efficiency • Gloss • Sheen

32. Many variables are considered to influence the BASIC COATING FILM PROPERTIES, however when analyzed these key factors boil down to..... 5 basic factors: • Pigment Volume Concentration (PVC) • Film Density • Coating Thickness • Substrate Adhesion • Film Cohesion Properties ( internal forces )

33. Key Performance Factors • Paying attention to these 5 basic factors helps Minimize & Resist : • chalking • cracking • brittleness • peeling • gloss reduction • abrasion problems • delamination • blistering

34. These5 basic factors, primarilycontrol the films: Coating Film Performance Protective, Functional & Aesthetic Properties

35. Agenda: Design Criteria • 1. Introduction • 2. Understanding the Basic Formula Components • 3. Key Properties that Affect Performance • 4. Key Coatings Calculations used for Design • 5. Selection of Raw Materials for Starting Points • Polymers for Performance • Pigments for Enhanced Performance • 6. Questions and Answers needed for Coatings Design

36. Design Criteria Calculations • Formulating Tips : Coating Calculations can help: • Estimate and Satisfy key Performance properties while Reducing Trial & Errors. • Meet customer & market needs. • Optimize cost effectively. • Meet VOC regulations.

37. Key Design Criteria Calculations • Calculations grouped as follows: • I. Key Coating Calculations. • II. Specific Pigment Calculations. • III. Specific Binder Calculations. • IV. Cost Calculations.

38. Design Calculations • I. Key Coating Calculations. • VOC Content ( lbs./ gal ) • % Nonvolatile ( Solid content ) • Density ( lbs. / gal ) • Bulking Value ( gal / lb. ) • Vehicle Solids ( wt. % ) • Total Volatiles ( wt. % )

39. Key Components which influence Film Performance Properties # 1 .24 gals .25 gals .50 gals .01 gals Solvents Pigments Binder Additives Film Properties depend on Volumes, which factor in component densities.

40. Relative Effect of Major Coating Components on Coating Characteristics ( Type / Level ) 10 = most dependent 1 = less dependent Importance of Effect increases with number.

41. Relative Raw Material Costs ( As a % of Total Cost ) %

42. Agenda: Design Criteria • 1. Introduction • 2. Understanding the Basic Formula Components • 3. Key Properties that Affect Performance • 4. Key Coatings Calculations used for Design • 5. Selection of Raw Materials for Starting Points • Polymers for Performance • Pigments for Enhanced Performance

43. Starting Point considerations : In order of Importance: 1. Design a Durable and Serviceable Coating Film to meet performance specifications. 2. Design for ease of application; brush, roll, spray, 3. Design Mill base composition to give optimum pigment dispersion. Formulating Design Criteria

44. The Formulation Backbone Key Performance Properties are controlled by : • PVC / CPVC Ratios= £ • P/B Ratios

45. Dramatic changes in Film Behavior and Appearance occurs when passing through the CPVC : The CPVC is critical for design requirements & is the point where there is just sufficient binder to bind the pigment present. Formulating Design Criteria

46. CPVC : Critical Pigment Volume Concentration Formulating Design Criteria Visually : • Below the CPVC ( Va = 0 ) • Pigment is separated only by binder. • Above the CPVC ( Va > 0 ) • Air voids are present among mixture. Va = volume of entrained air within the pigment & binder mixture

47. Critical Pigment Volume Concentration • Experimental Data • PVC Plots CPVC Note: Sharp Inflection Point PVC

48. Critical Pigment Volume Concentration Adhesion Fracture Value CPVC = 0.36 PVC

49. Critical Pigment Volume Concentration Tensile Strength psi Film Strength CPVC= .54 PVC

50. Critical Pigment Volume Concentration Hiding Power Efficiency Hiding Power (sqm / g TiO2) CPVC= 0.36 PVC