BACKGROUND OF THE I NVENTION

1 . Field of the Invention. This invention relates to materials which are useful as nonionic surfactants.

2. Description of the Art Practices. Glycosides have long been known as materials which can function in detergent products. The glycosides are nonionic surfactants which are prepared through the reaction of a saccharide material and an alcohol . The alcohol portion of the molecule adds hydrophobic character whereas the saccharide portion of the molecule increases the water solubility. A measure of the degree of the water solubility can be obtained through a measurement known as the degree of polymeri¬ zation of the glycoside. The degree of polymerization (or DP) is conveniently measured as the average number of saccharide molecules which have been joined together in forming the glycoside.

Mansfield et al in U . S . Patent 3 , 640 ,998 issued February 8 , 1972 describes surfactants therein which have been reacted with ethylene oxide or propylene oxide. The apparent purpose in the Mansfield Patent for so treating the glycoside surfactant is to convert the residual fatty alcohol which was used in obtaining the glycoside to an alkoxyiated alcohol . The alkoxyiated alcohols are well known as nonionic surfactants. In the absence of treating the alcohol to form an alkoxyiated alcohol , Mansfield was left with a large portion of unreacted fatty material in the reaction mixture as well as large amounts of lower { non -surfactant) glycosides. The presence of unreacted

fatty material inhibits the cleaning ability of the composi¬ tion . Additionally , the presence of lower glycosides diminishes the capacity of the composition to clean effec¬ tively.

The use of glycosides in detergent composi¬ tions is disclosed in U . S. Patent 4 ,483 ,779 issued November 20 , 1984 to Llenado et al . The Llenado et al patent shows an unmodified glycoside surfactant in combination with other nonionic detergents including ethoxylated alcohols.

The preparation of glycosides containing alkoxy groups between the fatty residue and the saccharide portions of the glycoside molecule are de¬ scribed in U . S . Patent 3 ,219 ,656 to Boettner issued November 23 , 1965. Alkyl polyglycosides are described in U . S. Patent 3 ,598 ,865 issued August 10, 1971 to Lew. Glycosides containing ethylene glycol residues are described in U . S . Patent 3 ,737 ,426 issued June 5 , 1973 to Throckmorton et al . The reader is also referred to Tenside Detergents; January/ February 1973; New Bio¬ degradable Surfactants Derived From Starch : Prepara- tion and Properties; Throckmorton et al .

It has now been determined that the residual fatty alcohol leftover from preparing a glycoside can effectively be minimized through stripping out the excess alcohol and alkoxylating the remainder of the material therein . The reduction of lower glycoside content increases the cleaning ability of the desired products described herein. It has also been found that the alkoxyiated glycosides having a long chain hydrophobic

group are excellent surfactants. In particular, it has been found that the alkoxyiated glycoside surfactants need not be as highly polymerized with regard to the saccharide due to the inclusion in the molecule of sub¬ stantial amounts of lower alkylene oxide units.

Throughout the specification and claims per¬ centages and ratios are by weight, temperatures are in degrees Celsius and pressures are in KPascals over ambient unless otherwise indicated. The references cited in this patent are to the extent applicable herein incor¬ porated by reference.

SUMMARY OF THE COMPOSITION OF THE I NVENT ION The first aspect of the present invention describes a glycoside composition comprising :

(a) from about 50 parts to about 80 parts by weight of a glycoside of the formula R(OG) (EO) wherein R is from about 10 to about 20 carbon atoms , (OG) is a member selected from the group consisting of fructoside , glucoside , mannoside, galactoside, taloside, guloside, alloside, altroside, idoside, arabinoside, xyloside, lyxoside and riboside and mixtures thereof, EO is an ethylene oxide residue, and y is the average degree of ethylene oxide substitution oh the glycoside;

(b) from about 8 parts to about 40 parts by weight of a glycoside of the formula R(OG) (EO) x y where R is from about 10 to about 20 carbon atoms , x is at least 2; (OG) is a member selected from the group consisting of fructoside, glucoside, mannoside, galactoside, taloside, guloside, alloside, altroside, idoside, arabinoside, xyloside, lyxoside and riboside and mixtures thereof, EO is an ethylene oxide residue; and y is the average degree of ethylene oxide substitution on the glycoside, and;

(c) from about 0 parts to about 12 parts by weight of a glycoside of the formula L(OG) (EO) , where L is from about 1 to about 4 carbon atoms , z is at least 1 ; (OG) is selected from the group consisting

of fructoside, glucoside, mannoside, galactoside, taloside , guloside , alloside , altroside, idoside, arabinoside, xyloside, lyxoside and riboside and mixtures thereof, EO is an ethylene oxide residue, and y is the average degree of ethylene oxide substitution on the glycoside.

A second embodiment of the present invention is a glycoside composition comprising :

(a) from about 40 parts to about 90 parts of a glycoside of the formula R(OG) (AO) wherein R is from 10 to 20 carbon atoms , (OG) is a member selected from the group consisting of -fructoside, glucoside , mannoside , galactoside , taloside, guloside , alloside, altroside, idoside, arabinoside, xyloside, lyxoside and riboside and mixtures there- of, AO is an alkylene oxide residue , and y is the average degree of alkylene oxide substitution on the glycoside;

(b) from about 5 parts to about 55 parts by weight of a glycoside of the formula R(OG) (AO) x y wherein x is at least 2 , R contains from about 10 to about 20 carbon atoms , (OG) is a member selected from the group consisting of fructoside, glucoside, mannoside, galactoside, taloside , guloside, alloside, altroside, idoside, arabinoside, xyloside, lyxoside and riboside and mixtures thereof, AO is an alkylene oxide residue, and y is the average degree

of alkylene oxide substitution on the glycoside; and ,

(c) from about 0.1 parts to about 9.5 parts by weight of a glycoside of the formula L(OG) (AO) where L is from about 1 to about 4 carbon atoms; z averages at least 2; (OG) is selected from the group consisting of fructoside, glucoside, mannoside, galactoside, taloside, guloside, alloside, altroside, idoside , arabinoside, xyloside, lyxoside and riboside and mixtures thereof, AO is an alkylene oxide residue and mixtures thereof, and y is the average degree of alkylene oxide substitution on the glycoside.

A third embodiment of the present invention is a glycoside composition comprising :

(a) from about 15 parts to about 100 parts by weight of a glycoside of the formula R(OG) (AO) wherein R is from about 12 to about 20 carbon atoms;

(b) from about 10 parts to about 60 parts by weight of a glycoside of the formula R(OG) (AO) x y wherein R is from about 12 to about 20 carbon atoms and x is at least 2; provided further (OG) is selected from the group con¬ sisting of fructoside, glucoside, mannoside, galactoside, taloside, guloside, alloside, altroside, idoside, arabinoside, xyloside, lyxoside and riboside and mixtures

thereof; AO is selected from the group consisting of ethylene oxide and propylene oxide and mixtures there- of; y is at least 1 and the ratio of (a) to (b) is at least as great as 3 : 2.

A still further embodiment of the present invention is a glycoside composition comprising :

(a) from about 10 parts to about 100 parts by weight of a glycoside of the formula R (OG) (EO) wherein R is from about 12 to about 20 carbon atoms;

(b) from about 10 parts to about 60 parts by weight of a glycoside of the formula R(OG) (EO) wherein R is from about 12 to about 20 carbon atoms and x is at least 2; provided further (OG) is selected from the group con¬ sisting of fructoside , glucoside, mannoside , galactoside, taloside , guloside , alloside, altroside, idoside, arabinoside , xyloside, lyxoside and riboside and mixtures thereof; EO is an ethylene oxide residue; y is at least 1 and the ratio of (a) to (b) is greater than 1 .

DETAI LED DESCRI PTION OF THE INVENTION

It has been found in the present invention that a high percentage of a long chain monoglycoside which has been substituted with an alkylene oxide gives excellent detergency properties. It has further been found that the polyglycoside components of the present invention can be utilized having a lower DP than was previously known and also provide excellent detergency.

A further advantage of the present invention is in the discovery that if the short chain glycoside content is diminished that detergency will also be substantially improved. Lower glycoside as used herein means those materials having a short chain hydrophobic group on the molecule. Even though the lower glycosides can be alkoxyiated in accordance with the present invention thereby increasing the water soluble nature of the lower glycoside this does not render that material an effective detergent.

The glycosides employed may be any of the types of materials as previously described in the Summary, however, it is most preferred that glucose (dextrose) be the backbone thereby giving a glucosyl structure to the glycoside.

A glycoside is typically defined as the reaction product of a saccharide and hydrophobic moeity through an acetal mechanism. While etherification of a hydroxyl on the saccharide can give a glycoside , the acetal mechanism is the preferred route to the glycoside.

The compositions of the present invention are best practiced by obtaining a long-chain glycoside e.g. , where R is from 10 to 20 carbon atoms , preferably 12 to

20 carbon atoms and most preferably 12 to 18 carbon atoms in length . The value of R is also preferably an alkyl group, although alkenyl groups may also be em¬ ployed . Similarly , the value of R may contain an aromatic group such as an alkylphenyl , phenylalkyl , alkylbenzyl or the like. The hydrophobic group ( R) on the glycoside molecule, may also be substituted . Where substitution on the hydrophobic group is present, it is usually a hydroxyl group. However, it is generally desired that the hydrophobic group not be substituted .

The value of L as defined herein represents a lower hydrophobic group such as methyl , ethyl , propyl , isopropyl , sec-butyl or n-butyl group. The presence of the lower hydrophobic group in the molecuje results from the process used, to obtain the glycoside. That is , the starting materials for the glycoside are typical ly from a mixture of a lower alcohol and the saccharides as described in the Summary. Accordingly, the lower glycoside is first formed and then converted to the higher glycoside.

The saccharides are typically reacted as in the U. S. Patent 4,223 , 129 issued September 6 , 1980 to Roth et al . Basically, the lower glycoside is an intermediate product from the reaction of the saccharide and a short chain alcohol . The higher hydrophobic values for R as previously described (fatty alcohol) are obtained by transetherification of the lower glycoside with a higher alcohol . The lower glycoside as described in the Summary may be effectively removed by minimizing the amount left in the reaction mixture e.g . , pushing the conversion to the higher glycoside to completion . If

large amounts of lower glycosides are present during alkoxylation, they compete with the desired glycoside for the alkoxy group. It has been observed that the short chain glycosides are more reactive with the alkylene oxides than the higher glycosides thus making the removal of the former highly desirable. It has not previously been recognized that the lower glycoside is detrimental to the detergency of the higher glycoside product. Thus reducing the lower glycoside content is desirable. It is further suggested that the lower glycoside may be minimized by stripping or by precipita¬ tion due to differential solubility of the lower and higher glycosides in various solvents.

After the higher glycoside containing the requisite amount of lower glycoside is obtained , it is possible to react the higher glycoside to increase the DP of the saccharide material. The DP may be increased by heating in the presence of acid catalysts. An advantage of the present invention is that it has been determined by preparing the end components as described herein that the DP of the alkoxyiated glycoside need not be as high as believed required for a non-alkoxylated glycoside and yet be an effective detergent product. This is important as processing to increase the DP has the effect of darkening the product. A darkened product is of restricted value in formulations where light color is important. The value of x (DP) in the poiyglycoside is typically from about 2.2 to about 3.5.

The alkylene oxide units which may be used in the present invention for addition to the glycoside are preferably those which add a degree of water solubility

to the molecule. This , of course, may be determined experimentally by the amount that the water solubility of the glycoside is increased over that of the basic glycoside molecule. Practically speaking , the alkylene oxide units of which the present invention is mainly concerned are those derived from ethylene oxide or propylene oxide. It should also be mentioned that mixtures of ethylene oxide and propylene oxide are also within the scope of the present invention. Capping of the glycoside molecule through sequential reactions whereby ethylene or propylene oxide is added first, and then an amount of the remaining alkylene oxide is added to the molecule are also contemplated herein.

It is also _, desirable that the alkylene oxide when added to the glycoside molecule polymerize to form multiple alkylene oxide units from a single hydroxyi group on the saccharide portion of the glycoside mole- cule. It is believed that the number 2 hydroxyi on the saccharide molecule is most reactive under base con¬ ditions and thus a desired product to be formed herein is one in which the glycoside is substituted in the 2 position. It should also be noted that when adding propylene oxide to the glycoside that the potential exists to form either a primary or secondary hydroxyi group depending on the reaction. The secondary hydroxyi group is not particularly desired but is not noted to be harmful to the detergency of the alkoxyiated glycoside so formed.

The alkylene oxide may be added to the glycoside molecule by either acid or base catalysis. As acid catalysis favors polymer growth of the alkylene oxide

unit, side reactions may occur to form a polyalkylene oxide structure rather than to add the alkylene oxide to the glycoside molecule. The foregoing reaction can become particularly prevalent if small amounts of water are present in the reaction mixture which than favors the formation of the glycol. It is therefore desired that the water content be no more than about 5 percent by weight; preferably no more than 1 percent by weight of the reaction mixture. A preferred base for use in the present invention is an alkoxide-hydroxide such as those obtained from a mixture of the sodium or potassium hydroxide and methanol . The foregoing catalyst favors mono addition of the alkylene oxide to the free hydroxyls on the glycoside molecule.

The amount of the alkylene oxide added in the reaction is conveniently from about 1 mole to about 50 moles; preferably about 3 moles to about 20 moles by weight of the alkylene oxide per mole of the starting glycoside. The value of y which is a positive number indicates the degree of alkylene oxide adduction on the glycoside molecule. The alkylene oxide units may be block or randomly distributed. The average amount of alkylene oxide on the molecule is conveniently from about 1 to about 40; preferably from about 1 to about 30 moles per mole of glycoside.

While this invention suggests reacting a preformed long chain glycoside with an alkylene oxide, it is possible to alkoxylate a short chain glycoside and to then increase the hydrophobic chain length of the glycoside. Alternatively , the saccharide molecule may be reacted with the alkylene oxide and thereafter converted

to the glycoside by reaction with a short chain or long chain alcohol . In the former case the short chain alkoxyiated glycoside is then converted to the long chain alkoxyiated glycoside.

It is believed that the amount of lower glycoside remaining in the product is detrimental to the overall effectiveness of the long-chain alkoxyiated glycosides as a detergent. Therefore, it is desirable to minimize the glycoside content where the hydrophobjc moeity (L) , as previously described , is 4 or below. Thus the product is desired to be substantially free of lower glycosides. The mechanism for reducing the lower glycoside content has been previously discussed. It is also believed, that when the lower glycoside content is present in unrestricted amounts that the value of R in the long- chain glycoside must be increased. Where unrestricted amounts of lower glycosides are present increased amounts of long-chain alkoxyiated glycosides (whether the mono or polyglycoside) should be present (or added) to compensate for the presence of the lower glycoside.

It is further desirable herein that the amount of alkoxyiated higher glycoside, (higher monoglycoside plus the higher polyglycoside) be within a weight ratio to the lower glycoside (alkoxyiated or not) of from about 40 : 1 to about 6 : 1 ; preferably at least 10 times the amount of the lower glycoside. It is also preferred that the higher alkoxyiated monoglycoside (a) to the higher alkoxyiated polyglycoside (b) should be greater than 1 : 1 ; especially from about 9: 1 to about 3 :2; preferably from about 8:1 to about 2: 1 .

It is also desirable that the free fatty alcohol content in the present invention be less than about 2%; preferably less than 0.5% by weight as this material has been determined to interfere with detergency.

It is further desired that the alkylene oxide on either the long-chain monoglycoside or the long-chain polyglycoside contain at least one unit of repeating alkylene oxide units, e.g. polymerized with respect to the alkylene oxide. It is believed that through the polymerization of the alkylene oxide on the glycoside molecule that enhanced detergency will occur over a random distribution of the alkylene oxide around the hydroxyls on the glycoside molecule.

The reaction to add the alkylene oxide to the glycoside may be done in the presence of a solvent, typically an alcohol or an alkane. A suitable alkane is hexane, while the alcohol may be reactive or non- reactive to the alkylene oxide. A non-reactive alcohol is one such as t-butyl while a reactive alcohol is one such as any of the alcohols used to prepare the higher glycoside e.g. , 10-20 carbons. If a reactive alcohol is used , it may be allowed to form the alkoxylate at from 0% to 90%; preferably 5% to 80% by weight of the total detergent product. The foregoing is particularly useful where the alkoxylate of the reactive alcohol is capable of functioning as a surfactant.

EXAMPLE I The following is a suggested exemplification of the present invention. A reaction vessel containing a stirring mechanism is obtained . 90 parts of dodecyl polyglycoside mixture obtained from dextrose is added to the reaction vessel . The al kylpolyglycoside mixture contains 1 .2% moisture, 0.4% dodecyl fatty alcohol and an additional 10 parts of Neodol 23 alcohol from Shell . The Neodol 23 alcohol is approximately a 1 : 1 mixture of dodecyl and tridecyl alcohols. The DP of the poly¬ glycoside is approximately 2.95.

The contents of the reaction flask are heated to about 140-150°C and 0.75 parts of potassium hydroxide dissolved in 1 .7 parts of methanol is added to the reaction vessel .

The alkylene oxide utilized herein is propylene oxide and 12.7 parts is slowly added with the te p- erature maintained at from 125-130°C. It is observed that the viscosity of the reaction mixture is lowered as the propylene oxide is adducted to the al kylpoly¬ glycoside.

The reaction mixture is then purified and tested for its detergency. The product is observed to clean better than the starting glycoside. Substantial ly similar results are observed when 1 % by weight of butyl glycoside or its alkoxylates ( DP 2.95) remain in the product following propoxylation .

EXAMPLE I I A sealed reaction vessel of sufficient design to withstand 10 ,000 KPa pressure is evacuated and then charged with 307.5 parts of Product A which is 25.7% by weight dodecyl alcohol; 8.2% butyl glycoside; 66.1 % dodecyl glucoside and 0.21 % sodium methoxide. The glucosides are 1 .4 DP. Ethylene oxide is added to the reaction vessel to a pressure of 340 KPa. The reaction vessel is heated to 135°C and maintained between 135°C and 150°C until 161 parts of ethylene oxide is taken up. This first run ( B) is divided into 2 parts. One part is further reacted (to give Product C) by introducing 1 .2 parts of additional sodium methoxide, repressurizing as was previously discussed and further adding of ethylene oxide at 1 0-150°C unti l an additional 172 parts of ethylene oxide is consumed. Product B contains about 5 moles of ethylene oxide per mole of glucoside whi le Product C contains 10 moles of ethylene oxide per mole of glucosides.

EXAMPLE 1 1 1 The products of Example I I are tested as shown below. The results show a product ( B ) made according to the invention to be superior in wetting ability to Product A the standard. Product C made according to the present invention is superior in foaming to Product A. Products B and C exhibit excellent cloud points when compared to Product A . The cleaning properties of Products B and C are observed to be superior to Product A in cleaning cotton/ polyester and cotton fab¬ rics.

TABLE I

Sample A Sample B Sample ^' C

Produce Tested (No EO) (5 mole EO) (10 mole E0)

Draves (Seconds) 58 24 65

Ross Miles Foam Height 0 in. 15 mm 78 mm 87 mm

Ross Miles Foam Height 5 min. 15 mm 78 mm 87 mm

Surface Tension (Dynes/cm) .01% 32.4 30.9 31.6

Surface Tension (Dynes/cm) .10% 26.8 „ 30.8 27.2

Cloud Point (1% Solution) Cloudy Over Over at 22°C 93°C 93°C

Cloud Point (1% Solution in 87°C 74°C

10% NaCl)