Detergency Of Specialty Surfactants

ISBN:0-8247-0491-6 This book is printed on acid-free paper. Headquarters Marcel Dekker, Inc. 270 Madison Avenue, New York, NY 10016 tel: 212-696-9000; fax:212-685-4540 Eastern Hemisphere Distribution Marcel Dekker AG Hutgasse 4, Postfach 812, CH-4001 Basel, Switzerland tel: 41-61-261-8482; fax: 41-61-261-8896 World Wide Web http://www.dekker.com The publisher offers discounts on this book when ordered in bulk quantities. For more information, write to Special Sales/Professional Marketing at the headquarters address above. Copyright © 2001 by Marcel Dekker, Inc. All Rights Reserved. Neither this book nor any part may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopying, microfilming, and recording, or by any information storage and retrieval system, without permission in writing from the publisher. Current printing (last digit): 10 9 8 7 6 5 4 3 2 1 PRINTED IN THE UNITED STATES OFAMERICA Preface This book summarizes the knowledge about the use of some nontraditional surfac-tants in detergents. The emphasis is on laundry detergents, with some discussion of other detergencies such as hard-surface cleaning and personal washing. The sur-factants described in this volume are in the classic organic “head-tail” class of sur-factants rather than polymers or silicone surfactants. The book originated from presentations given by noted scientists and authors at recent World Detergent Con-ferences in Montreux, Switzerland, and at AOCS and CESIO congresses. Traditionally, powdered and liquid laundry detergents contained linear alkyl benzene sulfonates, ether sulfates, and alcohol ethoxylates as surfactants, along with builders, enzymes, polymers, and possibly bleaches as additional active in-gredients. These formulations dealt well with different types of dirt and stains under a variety of water conditions. In recent years, however, a number of specialty surfactants have been developed for use in detergents. Some of the materials are somewhat newer in a commercial sense, such as alkyl polyglucosides (APGs) and a-sulfomethyl esters. Other sub-stances, such as alkyldiphenyl oxide disulfonates, betaines, alkanolamides, and ethoxylated amines, have been known for years and used routinely in other indus-tries. In this volume, these ingredients are examined closely for advantages in deter-gents. Recent process improvements in producing new specialty surfactants such as ethoxylated methyl esters and alkyl ethylenediaminetriacetates have made their consideration as detergent ingredients necessary. New specialty surfactants have been investigated and some adopted commer-cially for a variety of reasons—environmental, safety, performance, and formu-lation properties. In the environmental area, suppliers want surfactants that iii iv Preface biodegrade rapidly and have low aquatic toxicity. The public also desires prod-ucts with low human toxicity and minimal skin/eye irritation. There has always been a need for surfactants that clean well overall, clean certain stains well, or are cost effective. What criteria distinguish a commodity surfactant from a spe-cialty one? In general, a specialty surfactant has these properties: 1. Smaller manufacturing volumes 2. Fewer producers 3. Special properties in some applications—low irritation, biodegradable, improved foam, etc. Specialty surfactants are mostly secondary surfactants, not the primary ingre-dient in a formulation, and garner somewhat higher prices in the marketplace. Normally, over time a surfactant once considered a specialty slowly becomes a commodity. However, some surfactant classes can have both commodity and specialty uses. In fact, it is sometimes possible to convert a commodity into a specialty. For instance, linear alkylbenzene sulfonate (LAS) is considered a com-modity. As such, it is sold either in the acid form at 96% active or as the sodium salt at 40% to 60% active. There are many producers of and applications for LAS. As a specialty, the sodium salt is sold as flakes at 90% active. Few produc-ers and few applications need this material, but it commands a higher price. One main use is for dry blending in powdered detergents for smaller manufacturers, where it makes it possible to avoid purchase of expensive spray-drying equip-ment. Here the special property is its physical form. The same is true of sodium lauryl sulfate (SLS). As a commodity, SLS is 30% active and has many producers and many applications. As a specialty, SLS is a powder that is 95% active and food grade. Again, there are few producers and few applications, the main one being toothpaste. Here the special property is its physical form and the fact that it is food grade. In this volume, the special properties of specialty surfactants are their perfor-mance in detergents. Detergent formulations have changed immensely in the past 10 years. Both powders and liquids are more concentrated, making for bet-ter cleaning per gram. Enzyme use has increased in detergents, requiring surfac-tants that are compatible with enzymes or have a synergistic cleaning effect. Washing machines that use less water and only cold water are becoming more common in North America. Washing temperatures are decreasing dramatically in Europe also. These conditions require ingredients that are low foaming and that disperse easily to clean well in cold water. In this volume of the Surfactant Series, originated by Martin Schick and pub-lished by Marcel Dekker, Inc., sugar-based surfactants such as alkyl polygluco-sides are discussed in Chapter 1. Anionics such as alkyldiphenyl oxide disulfonates and a-sulfomethyl esters are presented in Chapters 3 and 4, and a Preface v number of new nonionics, amphoterics, chelating surfactants, and multifunc-tional ingredients in Chapters 2, 5, and 6. Special topics such as surfactants for dry cleaning, prespotters, and softeners are included in Chapters 7 through 9. The information contained herein should help the formulator choose the best in-gredients for current detergent and cleaning formulas. This volume is related to the Surfactant Series’Volumes 59, on amphoterics, and 74 on novel surfactants, which can also be consulted. Floyd E. Friedli ... - tailieumienphi.vn