Report No. 83 ADHESIVES by WING SIEN FONG February 1973 A private report by the PROCESS ECONOMICS PROGRAM STANFORD RESEARCH INSTITUTE I MENLO PARK, CALIFORNIA
CONTENTS 1 INTRODUCTION........................ 2 SUMMARY... General Aspects... Technical Aspects... 3 INDUSTRYSTATUS... Classification of Adhesives... Advantages and Disadvantages of Adhesive Bonding... Adhesives Market in the United States by End Use... Adhesives Market in the United States by Base Material... Structure of the Adhesives Industry in the United States.. Adhesives Market in Japan... Adhesives Market in Western Europe... 1 3 3 4 13 13 14 15 20 25 26 29 4 ADHESION FUNDAMENTALS................... Mechanical Theory...... 33 Chemical (Chemisorption; Molecular Interaction) Theory.. 34 Electrostatic (Electrical; Electronic) Theory...... 34 Adsorption Theory...... 36 Diffusion Theory...... 37 Weak-Boundary-Layer Theory and Adhesive Failures...... 39 Water Effect...... 39 Stresses...... 39 Types of Forces...... 40 Wetting and Spreading...... 40 Work of Adhesion and Work of Cohesion...... 48 Surface Topography...... 49 Wetting Rate...... 50 '33 5 FORMULATION MATERIALS AND PHYSICAL FORMS OF ADHESIVES... Base Materials (Binders)... Acrylics... Acrylic Acid Diesters... Acrylonitrile-Butadiene (Nitrile Rubber)... Coumarone-Indene Resins... Cyanoacrylates... Epoxies... Ethylene-Vinyl Acetate Copolymers... Furanes... 53 57 59 60 61 62 63 64 66 67 V
CONTENTS 5 (continued) Ionomers... 68 Isocyanates... 69 Melamine Formaldehydes... : 1 : : : : : : 70 Phenol-Formaldehydes... 71 Phenoxies 72 Polyamides... 1 : 73 Polyamide-Imides... 74 Polybenzimidazoles (PBI)... 75 Polycarbonates..... 76 Polychloroprenes (Neoprenes)... 77 Polyesters, Saturated... 78 Polyesters, Unsaturated... 79 Polyimides (PI)... 80 Polyisobutylene, Polybutenes, and Butyl Rubber... 81 Polypropylene, Amorphous... '82 Polystyrenes...... 83 Polysulfides... a4 Epoxy-Polysulfides... a5 Polysulfones... 86 Polyurethanes... :.. 87 Polyvinyl Acetals... 1 1 88 Polyvinyl Acetates... 89 Polyvinyl Alcohols... 90 Polyvinyl Chlorides... : 91 Polyvinyl Alkyl Ethers... 92 Resorcinol Formaldehydes... 93 Rubber, Natural... 94 Rubber, Reclaimed... 95 Silicones... 96 Styrene-Butadiene (SBR)... 97 Urea-Formaldehydes.... 98 Additives... 99 Antioxidants... 99 Defoamers...... 99 Diluents... 99 Extenders... i.. 1 : : 1 :... 99 Fillers... 100 Plasticizers...... 100 Preservatives... 101 vi 0
CONTENTS 5 (continued) Solvents... Tackifiers... Thickeners... Physical Forms of Adhesives... Solutions (Lacquers)... Emulsions and Latexes (Aqueous Dispersions)... Solids... Films (and Tapes)... Pastes... Encapsulated Adhesives... Hot Melt Adhesives... 101 102 102 102 103 103 104 104 106 106 107 6 INDUSTRIAL ADHESIVES................... 109 Abrasives Adhesives... 109 Anaerobic Adhesives... 110 Aerospace and Aircraft Adhesives... 111 Automotive Adhesives... 111 Construction Adhesives... 116 Dental Adhesives... 116 Electrical and Electronic Adhesives... 120 Glass (Optical) Adhesives... 120 High Temperature Adhesives... 127 Hot Melt Adhesives... 128 Low Temperature Adhesives... 136 Metal Adhesives... 136 Paper and Related Products Adhesives... 137 Photographic Film Adhesives... 147 Plastics Adhesives... 147 Pressure Sensitive Tapes... 160 Rubber Products (Tires) Adhesives... 173 Shoe Adhesives... 174 Structural Adhesives... 174 Surgical Adhesives... 188 Textile Adhesives... 188 Wood Adhesives... 198 Vii
CONTENTS 7 BONDINGTECHNIQUES... Joint Design for Structural Parts... Surface Preparation... 1... Methods... Quality of Water Used in Surface Preparation... Primers for Protecting Prepared Surfaces... Cleanliness Test for Prepared Surfaces... Preparation of Metals... Preparation of Plastics (Including Reinforced Plastics). Preparation of Elastomers... Preparation of Glass, Ceramics, and Other Inorganic Materials... Preparation of Fibrous Products... Preparation of Wood and Related Products... Application of Adhesives in General... Air-Knife Coating... Brush Coating... Calender Coating... Cast Coating... Curtain Coating... Dip Coating... Dust Coating... Extrusion Coating... Knife (or Blade) Coating... Rod Coating... Roll Coating Screen Coating...: 1 1 1 1 1 1 1 1 1 1 1 Spray Coating... Methods of Applying Pressure... Methods of Heating... Application of Hot Melt Adhesives... Production of Plywoods and Composition Boards... Adhesive Lamination of Fabrics... Preparation of Adhesive Coated Cords for Tire Manufacturing... 8 EVALUATIONS OF REPRESENTATIVE PROCESSES... Production of Phenol- and Urea-Formaldehyde Resins for Adhesives... Review of Processes... Process Description... Process Discussion... i... Cost Estimates... viii 211 215 215 219 222 222 223 223 239 239 240 240 242 242 242 243 243 245 245 246 247 247 248 248 249 253 253 255 256 256 259 267 267 273 273 273 274 281 282
CONTENTS 8 (continued) Manufacture of Continuous, Pressure Sensitive Adhesive Products... Review of Processes... Process Description... Process Discussion... Cost Estimates... APPENDIX DESIGN AND COST BASIS................ CITED REFERENCES........................ PATENT REFERENCES....................... 289 289 290 295 297 301 307 341 ix
ILLUSTRATIONS. 7.1 Bonding Processes... 7.2 Types of Joints... 7.3 Surface Treatments for Aluminum and Alloys... 7.4 Surface Treatments for Copper and Alloys... 7.5 Surface Treatments for Magnesium and Alloys... 7.6 Surface Treatments for Stainless Steels... 7.7 Surface Treatments for Steel and Ferrous Alloys (Excluding Stainless Steels)... 7.8 Surface Treatments for Titanium and Alloys... 7.9 Surface Treatments for Elastomers... 7.10 Brush and Calender Coatings... 7.11 Typical Roll Arrangements in Roll Coating... 1.. 7.12 Screen Coatings... 7.13 Application Methods for Hot Melt Adhesives... 7.14 Typical Production Schemes for Plywoods... 7.15 Typical Production Schemes for Hardboards and Insulation Boards... 7.16 Typical Production Scheme for Particle Boards... 7.17 Typical Adhesive Lamination of Fabrics... 7.18 Preparation of Adhesive Coated Cords for Tire Manufacture... 8.1 Production of Resinous Base Materials for Wood Adhesives... 8.2 Production of Resinous Base Materials for Wood Adhesives Effect of Plant Capacity and Stream Factor on Production Cost... 8.3 Manufacture of Continuous, Flexible, Pressure Sensitive Adhesive Products in Rolls... 8.4 Manufacture of Continuous, Flexible, Pressure Sensitive Adhesive Products in Rolls Effect of Plant Capacity and Stream Factor ' on Production Cost... 213 217 225 229 231 235 237 238 241 244 251 254 257 261 263 265 268 269 279 288 293 300 Xi
TABLES 2.1 Areas of Application for Various Adhesives....... 5 2.2 Summary of Projected Growth and Recent Consumption Data for Some Major Adhesives and Applications in United States.................... 7 2.3 Cost Estimates for the Production of Resinous Base Materials for Wood Adhesives and the Manufacture of Continuous, Flexible, Pressure Sensitive Adhesive Products in Rolls.......... 11 3.1 Adhesives Production and End-Use Pattern in Japan,... 27 3.2 Uses of Some Major Types of Adhesives in Japan..... 28 4.1 Types of Attractive Forces............... 41 4.2 Relative Electronegativity and Dipole Moment for Some Elements and Polar Groups, Some Hydrogen Bond Donors and Acceptors, and Some Easily Polarized Groups.................... 42 4.3 Critical Surface Tensions................ 46 5.1 Factors for Formulating or Selecting Adhesives..... 55 6.1 Anaerobic Adhesives Summary of Some Recent Composition-of-Matter Patents.. 112 6.2 Adhesives for the Automotive Industry.......... 115 6.3 Adhesives for the Construction Industry Summary of Some Recent Composition-of-Matter Patents.. 117 6.4 Dental Adhesives Summary of Some Recent Composition-of-Matter Patents.. 121 6.5 Adhesives for the Electrical and Electronics Industry Summary of Some Recent Composition-of-Matter Patents.. 122 6.6 Adhesives for Glass and Related Products Summary of Some Recent Composition-of-Matter Patents.. 124 6.7 High Temperature Adhesives Summary of Some Recent Composition-of-Matter Patents.. 129 6.8 Hot Melt Adhesives Typical Ingredients..,................ 130 6.9 Hot Melt Adhesives Summary of Some Recent Composition-of-Matter Patents.. 131 Xiii
TABLES 6.10 Adhesives for Bonding Metal to Metal Summary of Some Recent Composition-of-Matter Patents.. 138 6.11 Adhesives for Bonding Metal to Plastic or Other Nonmetal Summary of Some Recent Composition-of-Matter Patents.. 143 6.12 Adhesives for Paper and Related Products Summary of Some Recent Composition-of-Matter Patents.. 148 6.13 Adhesives for Photographic Film Summary of Some Recent Composition-of-Matter Patents.. 152 6.14 Adhesives for Plastics Summary of Some Recent Composition-of-Matter Patents,. 154 6.15 Adhesives for Pressure Sensitive Tapes and Related Products Summary of Some Recent Composition-of-Matter Patents.. 164 6.16 Resorcinol-Based Adhesives for Bonding Rubber to Cords (for Tires) Summary of Some Recent Composition-of-Matter Patents.. 175 6.17 Adhesives, Other than Resorcinol-Based, for Bonding Rubber to Cords (for Tires) Summary of Some Recent Composition-of-Matter Patents.. 181 6.18 Adhesives for Shoes Summary of Some Recent Composition-of-Matter Patents., 184 6.19 Adhesives for Honeycomb Structures Mechanical Properties Requirements........... 187 6.20 Common Structural Adhesives Typical Properties................... 189 6.21 Structural Adhesives Summary of Some Recent Composition-of-Matter Patents.. 193 6.22 Surgical Adhesives Summary of Some Recent Composition-of-Matter Patents.. 194 6.23 Adhesives for Medical Tapes and Related Products Summary of Some Recent Composition-of-Matter Patents.. 195 6.24 Adhesives for Fabrics in General Summary of Some Recent Composition-of-Matter Patents.. 199 6.25 Adhesives for the Manufacture of Nonwoven, Flocked, and Related Fabric Products Summary of Some Recent Composition-of-Matter Patents.. 202 xiv
TABLES 6.26 6.27 8.1 8.2 8.3 8.4 8.5 8.6 8.7 Adhesives for Bonding Wood to Wood or Polymeric Materials Summary of Some Recent Composition-of-Matter Patents.. Adhesives Based on Phenolic Resins Examples of Formulations for Use in Plywood....... Production of Resinous Base Materials for Wood Adhesives Major Process Equipment and Utilities Summary...... Production of Resinous Base Materials for Wood Adhesives Total Capital Investment................ Production of Resinous (Phenolic) Base Materials for Wood Adhesives Production Costs.................... Production of Resinous (Urea) Base Materials for Wood Adhesives Production Costs.................... Manufacture of Continuous, Flexible, Pressure Sensitive Products in Rolls Major Process Equipment and Utilities Summary...... Manufacture of Continuous, Flexible, Pressure Sensitive Products in Rolls Total Capital Investment................ Manufacture of Continuous, Flexible, Pressure Sensitive Products in Rolls Production Costs...,.........,.,.... 204 208 277 285 286 287 293 298 299 xv