CONTENTS

CONTENTS

Introduction: Classification of Synthetic Tannins

PART I SECTION I

The Synthesis of Vegetable Tannins

1. Tannin
2. Digallic Acid
3. Ellagic Acid
4. Depsides
     Carbomethoxylation of Hydroxybenzoic Acids
     Chlorides of Carbomethoxyhydroxybenzoic Acids
     Preparation of Didepsides
     Preparation of Tridepsides
     Preparation of Tetradepsides
     Tannoid Substances of the Tannin Type
     Chart showing the Decomposition of Products of Tannin

SECTION II

Synthesis of Tanning Matters

1. Aromatic Sulphonic Acids
2. Condensation of Phenols
     Condensation of Hydroxybenzene
     Condensation of Dihydroxybenzene
     Trihydroxy benzene
     Polyhydroxybenzenes
     Quinone
     Phenolic Ethers
     Nitro Bodies
     Amino Bodies
     Aromatic Alcohols
     Aromatic Acids
3. Condensation of Naphthalene Derivatives
4. Condensation of the Anthracene Group
5. Di- and Triphenylmethane Groups
6. Summary

Table

SECTION III

Tanning Effects of Mixtures and Natural Products

1. Mixture of Phenolsulphonic Acid and Formaldehyde 2. Mixture of Phenolsulphonic Acid and Natural Tannins 3. Tanning Effects of Different Natural Substances

SECTION IV

Methods of Examining Tanning Matters

PART II

Synthetic Tannins: Their Industrial Production and Application

A. Condensation of Free Phenolsulphonic Acid
B. Condensation of Partly Neutralised Phenolsulphonic Acid
C. Condensation of Completely Neutralised Phenolsulphonic Acid
D. Condensation of Cresolsulphonic Acid
E. Relative Behaviour of an Alkaline Solution of Bakelite and
   Natural Tannins
F. Dicresylmethanedisulphonic Acid (Neradol D)
     1. Neradol D Reactions
     2. Electro-Chemical Behaviour of Neradol D
     3. The Influence of Salts and Acid Contents
        on the Tanning Effect of Neradol D
     4. Phlobaphene Solubilising Action of Neradols
     5. Effect of Neradol D on Pelt
     6. Reactions of Neradol D with Iron and Alkalies
     7. Reagents suitable for Demonstrating the
        Various Stages of Neradol D Tannage
     8. Combination Tannages with Neradol D
          (1) Chrome Neradol D Liquors
          (2) Aluminum Salts and Neradol
          (3) Fat Neradol D Tannage
     9. Analysis of Leather containing Neradol D
     10. Properties of Leather Tanned with Neradol D
     11. Neradol D, Free from Sulphuric Acid
     12. Neutral Neradol
G. Different Methods of Condensation as Applied to
   Phenolsulphonic Acid
     1. Condensation Induced by Heat
     2. Condensation with Sulphur Chloride
     3. Condensation with Phosphorus Compounds
     4. Condensation with Aldehydes
     5. Condensation with Glycerol

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