Cleaning with Solvents: Science and Technology

<p>Preface</p> <p>Acknowledgments</p> <p>Disclaimer</p> <p>What You Can Do with This Book</p> <p>A Note on Organization</p> <p>Units Used in This Book</p> <p>External References Cited in This Book</p> <p>Chapter 1. Relationship of Solvent Properties to Structure</p> <p>Abstract</p> <p>1.1 Background</p> <p>1.2 The Elements of Cleaning Solvents</p> <p>1.3 The Incredible Shrinking Periodic Table</p> <p>1.4 A Solvent can be Elements Arranged in a Structure</p> <p>1.5 A Solvent can also be a Structure Populated with Additional Elements</p> <p>1.6 The Future of Solvent Design</p> <p>1.7 Specific Relationships of Composition and Structure to Solvent Properties</p> <p>1.8 Solvent Design is Multidimensional</p> <p>1.9 Solvent Design Goals</p> <p>1.10 Design of Non-Traditional Solvents</p> <p>1.11 Solvent Selection</p> <p>Chapter 2. Solubility Scales (Parameters)</p> <p>Abstract</p> <p>2.1 Absolute and Relative Information</p> <p>2.2 Molecular Soup</p> <p>2.3 May the Force(s) be With You</p> <p>2.4 Solubility Parameters</p> <p>2.5 Kauri Butanol (Kb) Value</p> <p>2.6 Other Measures of Solvency</p> <p>2.7 Hildebrand Solubility Parameter</p> <p>2.8 Hansen Three-Dimensional Solubility Parameters</p> <p>2.9 Numerical Values of Hansen Solubility Parameters</p> <p>2.10 The Basic Approach – Comparison to Other Materials</p> <p>Chapter 3. Solvent Selection for Specific Tasks</p> <p>Abstract</p> <p>3.1 Background</p> <p>3.2 The Nature of Soils</p> <p>3.3 The Basic Approach to Solvent Selection</p> <p>3.4 This Author’s Approach</p> <p>3.5 Autopsy of Some Soils</p> <p>3.6 Food-Derived Residue</p> <p>3.7 Lubricants</p> <p>3.8 Greases</p> <p>3.9 Coolants or Hydraulic Fluids</p> <p>3.10 Polymer-Derived Residues</p> <p>3.11 Biological Residue(s)</p> <p>3.12 General Observations about Soils</p> <p>3.13 Use of Hansen Solubility Parameters in Solvent Selection</p> <p>3.14 Analysis for Specific Soil Components</p> <p>3.15 General Results from the Use of HSP</p> <p>3.16 Approach using Mixtures of Identified Soil Components</p> <p>3.17 Solvent Selection to Clean Collections of Soils</p> <p>3.18 Food-Derived Residue as a Soil Collection</p> <p>3.19 Soil Composition Really Doesn’t Matter</p> <p>3.20 Lubricants as a Soil Collection</p> <p>3.21 Grease as a Soil Collection</p> <p>3.22 Coolants or Hydraulic Fluids as a Soil Collection</p> <p>3.23 Polymer-Derived Residues as a Soil Collection</p> <p>3.24 Medical Residues as a Soil Collection</p> <p>3.25 A Summary of Lessons Concerning Cleaning Soil Composites</p> <p>3.26 Identification of the HSP Values of Industrial Soil Composites</p> <p>3.27 Working without Numbers—Use of the HSP without Soil Identification</p> <p>3.28 Limitations of HSP Separation (R_A) for Good Solvent Cleaning Performance</p> <p>3.29 About Cleaning of All Soils</p> <p>3.30 The Effect of Normal Boiling Temperature</p> <p>3.31 Vapor Degreasing vs. Cold Cleaning</p> <p>3.32 HSP for Vapor Degreasing vs. Cold Cleaning</p> <p>Chapter 4. SHE Management (Solvent Substitution)</p> <p>Abstract</p> <p>4.1 Background</p> <p>4.2 Why Substitute Solvents?</p> <p>4.3 REACH for the Stars</p> <p>4.4 Becoming Globally Harmonized</p> <p>4.5 Game Playing</p> <p>4.6 The Key Element in Successful Solvent Substitution</p> <p>4.7 What’s Important in Solvent Substitution?</p> <p>4.8 Examples of Practical Solvent Substitution</p> <p>4.9 Substitute Solvents for Trichloroethylene</p> <p>4.10 Enclosed Cleaning Machines</p> <p>4.11 Solvent Substitution and Use in Non-US Countries</p> <p>4.12 Summary: Solvent Substitution</p> <p>4.13 The Right to Know</p> <p>4.14 Hazardous Air Pollutants (HAPS)</p> <p>4.15 The Superfund</p> <p>4.16 Exposure Limits</p> <p>4.17 Future Impact of SHE Regulation</p> <p>Chapter 5. Toxicology of Cleaning Solvents</p> <p>Abstract</p> <p>5.1 Background</p> <p>5.2 Sources of Information</p> <p>5.3 A Prime Substitute for an MSDS</p> <p>5.4 Specific Hazard Information</p> <p>5.5 Analysis of Hazard Ratings</p> <p>5.6 Odor as a Protective Way to Avoid Toxicological Hazards</p> <p>Chapter 6. The VOC Exemption Game</p> <p>Abstract</p> <p>6.1 Background</p> <p>6.2 The Object of the Game</p> <p>6.3 US VOC Definition</p> <p>6.4 History of VOC Regulation in the US</p> <p>6.5 Estimation(s) of Atmospheric Reactivity</p> <p>6.6 The Meaning of Atmospheric Reactivity</p> <p>6.7 Numerical Values of MIR for Cleaning Solvents</p> <p>6.8 MIR Values within Solvent Types</p> <p>6.9 Comparison of Ozone Generation by Solvent Type</p> <p>6.10 Selection of Low VOC Solvents by Structure and Type</p> <p>6.11 Game Winners! VOC Exempt Solvents</p> <p>6.12 The Usable Winners</p> <p>6.13 Those Who Wish to Play: Applicants for VOC Exemption</p> <p>6.14 Other Countries—Games with Different Rules</p> <p>6.15 Volatility and Reactivity Don’t Intersect</p> <p>6.16 An Immodest Proposal</p> <p>Chapter 7. Economics of Solvent Use</p> <p>Abstract</p> <p>7.1 Background</p> <p>7.2 Transition from Then to Now</p> <p>7.3 Solvent Price vs. Solvent “Power”</p> <p>7.4 Prices of Families of Similar Solvents</p> <p>7.5 Solvent Prices</p> <p>7.6 Management of Cleaning Solvents</p> <p>7.7 The US Resource Recovery and Conservation Act (RCRA)</p> <p>7.8 The Property of Overkill</p> <p>7.9 Size Does Matter</p> <p>7.10 Getting There is Not Half the Fun</p> <p>7.11 Unnatural Selection</p> <p>7.12 Treatment/Disposal of Cleaning Wastes</p> <p>7.13 About “My” Solvent</p> <p>7.14 The Third Requirement of Hazardous Waste Generators (On-Site Treatment)</p> <p>7.15 Economics of On-Site Waste Treatment</p> <p>7.16 Chemical Management Services</p> <p>7.17 Chemical Leasing</p> <p>7.18 A Case of Need</p> <p>Chapter 8. Solvent Azeotropes</p> <p>Abstract</p> <p>8.1 Background</p> <p>8.2 About SHE-Driven Change</p> <p>8.3 Binary Azeotropes</p> <p>8.4 Methodology for Choosing Replacement Azeotropic Solvent Blends</p> <p>8.5 Specific Replacements</p> <p>8.6 Binary Azeotropes Totally VOC Exempt (in US)</p> <p>8.7 Binary Azeotropes Containing Water</p> <p>8.8 Binary Azeotropes to Replace Other Solvents: Summary</p> <p>8.9 Use of Azeotropes vs. Non-Azeotropic Blends in Solvent Cleaning</p> <p>8.10 Commercial Solvent Blends for Immersion Cleaning</p> <p>Chapter 9. Wipe Cleaning with Solvents</p> <p>Abstract</p> <p>9.1 Background</p> <p>9.2 Who Does Wipe Cleaning?</p> <p>9.3 Why Do Wipe Cleaning?</p> <p>9.4 Roles of the Solvent in Wipe Cleaning</p> <p>9.5 Freon (CFC-113)—The Perfect Wipe Solvent</p> <p>9.6 HCFC-225ca/cb—the Imperfect Wipe Cleaning Solvent</p> <p>9.7 HFEs/HFCs/OSs—Partially Perfect Wipe Cleaning Solvents</p> <p>9.8 Wipe Cleaning Solvents Based on Commodity Chemicals</p> <p>9.9 Wipe Cleaning Solvents Based on Slowly Evaporating Commodity Solvents</p> <p>9.10 Water-Based Wipe Cleaning Solvents</p> <p>9.11 Multi-Component Wipe Clean Solvents</p> <p>9.12 The Option to “Roll Your Own” Wipe Clean Solvent</p> <p>9.13 The No-Compromise Wipe Cleaning Solvent</p> <p>9.14 The Joy of Compatibility</p> <p>9.15 The Plan to Manage Use of Wipe Clean Solvents</p> <p>9.16 The Necessity for Compromise</p> <p>9.17 Solvent Selection for Wipe Cleaning</p> <p>9.18 Paint Stripping by Wipe Cleaning</p> <p>9.19 Relief from Residues</p> <p>Chapter 10. Cleaning with Solvent Aerosols</p> <p>Abstract</p> <p>10.1 Background</p> <p>10.2 The Perfect Aerosol-Dispensed Solvent Product</p> <p>10.3 Any Aerosol—How It’s Produced</p> <p>10.4 The Aerosol Can Clean, But in a Different Way</p> <p>10.5 The Aerosol Can</p> <p>10.6 Marketing 101</p> <p>10.7 General Applications for Aerosol Cleaning</p> <p>10.8 The Secret Ingredient (Two Chlorine Atoms)</p> <p>10.9 Properties of Commercial Aerosol-Delivered Solvent Products</p> <p>10.10 A Flammable Aerosol—Defined</p> <p>10.11 The Meaning of Explosive Limits</p> <p>10.12 Prevention of the Ignition of Aerosols</p> <p>10.13 Selection of Commercial Blends for Minimum Flammability Risk</p> <p>10.14 Ignition Safety of Aerosols: Summary</p> <p>10.15 Hazards Unrelated to Flammability of Aerosols</p> <p>10.16 Cleaning Potential with Commercial Blends of Aerosol-Delivered Solvents</p> <p>10.16 Differentiation among Blends</p> <p>10.17 Summary</p> <p>Chapter 11. Stabilization of Solvents</p> <p>Abstract</p> <p>11.1 Background</p> <p>11.2 The Nature of Solvent Stabilization</p> <p>11.3 The Perfect Solvent</p> <p>11.4 Reaction Pathways of Solvent Degradation</p> <p>11.5 The Instability of Stabilization</p> <p>11.6 Illustration of Degradation</p> <p>11.7 A General Method of Solvent Stabilization</p> <p>11.8 Removal of Water</p> <p>11.9 Design of Stabilizer Packages</p> <p>11.10 Specific Stabilizer Materials</p> <p>11.11 Formulation of Stabilizer Packages</p> <p>11.12 Problems with Use of Stabilizer Packages</p> <p>11.13 Misconceptions about Stabilizer Packages</p> <p>11.14 Recommended Control Strategies</p> <p>11.15 A Non-Recommended Control Strategy</p> <p>11.16 Acid Acceptance Testing</p> <p>11.17 Stabilizer Booster Packages</p> <p>11.18 Opinions</p> <p>11.19 Learn From Others</p> <p>11.20 Composition of Commercial Stabilizer Packages</p> <p>11.21 Stabilization of Non-Halogenated Solvents</p> <p>11.22 In Times of Stress</p> <p>11.23 Some Simplicity</p> <p>Chapter 12. Solvent Cleaning: Questions and Answers</p> <p>Abstract</p> <p>12.1 Background</p> <p>12.2 Why is Solvent Cleaning Preferred?</p> <p>12.3 why isn’t Aqueous Cleaning Technology Preferred?</p> <p>12.4 Which is More Hazardous, Solvent or Aqueous Technology?</p> <p>12.5 Is There a Future for Solvent Cleaning in the Us Despite More Restrictive Regulations?</p> <p>12.6 1,1,1-Trichloroethane (TCA) was the “Right” Solvent Prior to the 1990s; Which One is Now?</p> <p>12.7 Solvent Technology Seems to be Widely Opposed as “Toxic.” How can One Get Unbiased Advice?</p> <p>12.8 Why are Cleaning Solvents Priced so High?</p> <p>12.9 Why are Cleaning Solvents Produced in China Priced so Cheaply?</p> <p>12.10 Are Cleaning Solvents Imported from China of Acceptable Quality?</p> <p>12.11 Why is there so Much Secrecy in Cleaning Technology?</p> <p>12.12 Why do Prices for Cleaning Solvents Vary so much Among Suppliers?</p> <p>12.13 Are Offerings from Suppliers of Cleaning Solvents Interchangeable?</p> <p>12.14 Why are Solvents not Now Recognized as Cleaning Solvents Described Here?</p> <p>12.15 About odor Thresholds: Some Workers find the odor of Organic Cleaning Solvents Objectionable. What Should be Done?</p> <p>12.16 Is any Firm Seeking to Develop New Cleaning Solvents?</p> <p>12.17 Does the Selling Price of Cleaning Solvents Really Matter?</p> <p>12.18 What is “Fire Point?” How is it Different from Flash Point? should I Care?</p> <p>12.19 How is One to Select a Supplier of Cleaning Solvents (and Equipment)?</p> <p>12.20 If I Convert to a Cleaning Solvent Rated “Combustible,” How am I to Dry the Parts?</p> <p>12.21 High Energy Prices Affect my Costs, How can that Burden be Reduced?</p> <p>12.22 How is Cleaning Done in Remanufacturing Operations Different from that Done in Manufacturing Operations?</p> <p>Group A. Basic Information</p> <p>Introduction</p> <p>Appendix A1. Basic Data about Cleaning Solvents</p> <p>Appendix A2. Estimation of Properties of Solvent Blends</p> <p>A Blend Compositions</p> <p>B Hansen Solubility Parameters of Blends</p> <p>C Liquid Density of Blends</p> <p>D Liquid Viscosity of Blends</p> <p>E Heat of Vaporization of Blends</p> <p>F Surface Tension of Blends</p> <p>G Exposure Limits of Blends</p> <p>H Molecular Weight of Blends</p> <p>I Composite Vapor Pressure</p> <p>J Activity Coefficients of Blends</p> <p>K Flash Points of Blends</p> <p>L Lower Explosion (Flammability) Limits of Blend Components</p> <p>M Maximum Incremental Reactivity (MIR)</p> <p>N Lower Explosion (Flammability) Limits of Blends</p> <p>O Relative Evaporation Rate (RER) of Blends</p> <p>Working Examples</p> <p>Appendix A3. Derivation of Blend Rule for Solubility Parameters</p> <p>Appendix A4. Compatibility of Wipe Cleaning Solvents with Surface Materials and Protective Gloves (With Database)</p> <p>A Harmful Effects of Solvents on Surface Materials</p> <p>B Differences between Machine and Wipe Cleaning</p> <p>C Solvent/Surface Compatibility Database</p> <p>D DESCRIPTION OF THE DATABASE</p> <p>E Reorganization of the Database to Focus on Specific Surfaces</p> <p>F Elastomers</p> <p>G Plastics</p> <p>H Metals</p> <p>I Glove Materials</p> <p>J Use of these Appendices</p> <p>Appendix A5. Management of Flow of Cleaning Solvents to Wet Surfaces (The Wettability Index and the Dimensionless Ohnesorge Number)</p> <p>A Flow of Fluids</p> <p>B Restricted Fluid Flow</p> <p>C Physical Properties</p> <p>D Solvents are Fluids</p> <p>E The Wetting Index</p> <p>F Limitations of the Wetting Index</p> <p>G Dimensionless Numbers</p> <p>H The Ohnesorge Number</p> <p>I Meanings of the Ohnesorge Number</p> <p>J Mechanisms Associated with the Ohnesorge Number</p> <p>K Use of the Ohnesorge Number</p> <p>L Summary</p> <p>Group B. Reduction of Ozone Formation by VOCs</p> <p>Introduction</p> <p>Appendix B1. Chemistry of Atmospheric Reactions of VOCs Leading to Smog</p> <p>A Overall Summary</p> <p>B Combustion-Related Smog (CRS)</p> <p>C Chemistry of CRS</p> <p>D Smog Formed with VOCs (Photochemical Smog)</p> <p>E Distribution of Nitrogen Oxides AffectS Ozone Formation</p> <p>F Reactions and Removal of Free Radicals</p> <p>G Reactivity Metrics (MIR)</p> <p>H Reactivity Metrics (kOH)</p> <p>I Summary</p> <p>Appendix B2. Calculation of MIR through Group Contribution Methods</p> <p>A The Leveling Effect of Maximization</p> <p>B Prediction of MIR through Group Contribution Analysis</p> <p>C Results</p> <p>D The Anomaly!</p> <p>E Application of Results</p> <p>F Summary</p> <p>Group C. Solubility Parameters</p> <p>Appendix C1. Optimization Method for Determination of Solubility Parameters</p> <p>A Methodology of an Optimization</p> <p>A.1 Definition of Correctness</p> <p>A.2 Mathematical Criteria to Define an Optimum</p> <p>A.3 Method of Variation of Parameters</p> <p>Appendix C2. Estimation of Hansen Solubility Parameters (HSP) from Binary Data—PES</p> <p>A Example Data for Parameter Evaluation</p> <p>B Estimation of HSP Using Binary Data—Polyethersulfone Polymer (PES)</p> <p>Appendix C3. Estimation of HSP from Multilevel Data—Bitumen</p> <p>A Optimization of HSP for Bitumen</p> <p>B Bitumen is Similar to a Soil</p> <p>C Hansen Solubility Parameters are Not Legal Tender</p> <p>Appendix C4. Estimation of HSP from Solvent Mixtures</p> <p>A Selection of Cleaning Solvents</p> <p>B Post-Experimental Analysis for Consistency</p> <p>C Photoresist Materials (Soils)</p> <p>D Analysis of PR1 Cleaning Tests</p> <p>E Analysis of Unexpected Solvency Performance</p> <p>F Local VS. Global Optima</p> <p>G When a Picture May Not be Worth Any Words</p> <p>H Evaluation of Cold Cleaning with another Photoresist</p> <p>I Rate Processes</p> <p>Appendix C5. Estimation of HSP from Correlations</p> <p>A Estimation of HSP via Correlations</p> <p>B Estimation of the Disperse Solubility Parameter</p> <p>C Estimation of the Polar Solubility Parameter</p> <p>Appendix C6. Estimation of HSP using the “Pythagorean Theorem”</p> <p>A Estimation of All HSP using The “Pythagorean Theorem”</p> <p>Appendix C7. Estimation of HSP from an Equation of State</p> <p>A Two Fundamental Building Blocks</p> <p>B Implementation of the Fundamentals</p> <p>C Calculated Outcomes vs. Accepted HSP Values</p> <p>D Analysis of Outcomes</p> <p>E Summary</p> <p>Appendix C8. Estimation of HSP from Group Contribution Methods</p> <p>A Relationship to Other Methods</p> <p>B About Group Contribution Methods</p> <p>C Group Contribution Methods for Hansen Solubility Parameters</p> <p>D The Method of Stefanis and Panayiotou</p> <p>E Application of the Stefanis Panayiotou Method</p> <p>F A Specific Example</p> <p>G Use of Group Contribution Methods for HSP via Neural Networks</p> <p>H Comparison of Estimation Methods for HSP</p> <p>I The Critical Flaw in All Group Contribution Systems for Solubility Parameters: Group Identification</p> <p>Appendix C9. Estimation of HSP for Soil Mixtures</p> <p>A Reasons for Determination of HSP by Solubility Experiments</p> <p>B Methods for Solvent Selection with HSP via Solubility Experiments</p> <p>C Methods of Determining Solubility/Insolubility</p> <p>D Determination of HSP for Soil Materials: Summary</p> <p>Appendix C10. Hoy Solubility Parameters</p> <p>A Other Solubility Parameters</p> <p>B Hoy Solubility Parameters</p> <p>C Calculation of the Hoy Total Solubility Parameter</p> <p>D Fractionation by Hoy of His Total Solubility Parameter</p> <p>E The Aggregation Number</p> <p>F Calculation of the Polar Attraction Constant (F_P)</p> <p>G Calculation of Hoy's Hydrogen Bonding Solubility Parameter</p> <p>H Calculation of Hoy's Polar Solubility Parameter</p> <p>I Calculation of Hoy's Disperse Solubility Parameter</p> <p>J Calculated Results of Hoy Solubility Parameters</p> <p>K Group Contribution Constants Used to Produce Hoy Solubility Parameters</p> <p>L Unique Advantages of the Hoy Solubility Parameters</p> <p>M Hoy Solubility Parameters from Functional Group Analysis</p> <p>N Non-Interchangeability of Functional Groups</p> <p>O Hoy Solubility Parameters of Polymers</p> <p>P Equivalence of Hoy and Hansen Solubility Parameters</p> <p>Q Hoy Solubility Parameters for Non-Polymeric Soils</p> <p>R Choice of Systems of Solubility Parameters</p> <p>Appendix C11. Values of Hansen Solubility Parameters for Solvents, Soils, and Polymers</p> <p>A Hansen Solubility Parameter Data About Cleaning Solvents</p> <p>B Hansen Solubility Parameter Data About Soil Components</p> <p>C Hansen Solubility Parameter Data About Polymeric Materials</p> <p>Appendix C12. The Teas Graph</p> <p>A Fractional Solubility Parameters (the Teas Graph)</p> <p>B How to Use the Teas Graph</p> <p>C A Limitation of the Teas Graph</p> <p>D A Crucial Flaw of the Teas Graph</p> <p>Group D. Solvent Substitution</p> <p>Introduction</p> <p>Appendix D1. Examples and Methodology of Solvent Substitution</p> <p>A VOC Exemption in Aerospace Wipe Cleaning</p> <p>B No Change in Time to Complete Dryness</p> <p>C Improved Flammability Ratings</p> <p>D Substitution for Trichloroethylene</p> <p>E Substitution for Benzene</p> <p>F Substitution for Methylene Chloride</p> <p>G Substitution for Perchloroethylene</p> <p>H Substitution for Methyl Ethyl Ketone (MEK)</p> <p>I Substitution for CFC-113 as a Wipe Clean Solvent</p> <p>J Selection Based on Evaporation Rate</p> <p>K Selection Based on Surface Tension</p> <p>L The Missing Unit Operation</p> <p>M Solvent Substitution Examples: Summary</p> <p>Appendix D2. Examples of Solvent Substitution to Achieve VOC Reduction</p> <p>A Background</p> <p>B Approaches for Solvent Substitution Based on Minimization of MIR Values</p> <p>C Substitution for Trichloroethylene</p> <p>Index</p>