WO1999064659A1

WO1999064659A1 - Alkyl polyglycosides and alkyl sulfates as penetrants in mercerizing baths

Info

Publication number: WO1999064659A1
Application number: PCT/US1999/011807
Authority: WO
Inventors: Howard Cole
Original assignee: Henkel Corp; Cognis Corp
Current assignee: Henkel Corp; Cognis Corp
Priority date: 1998-06-10
Filing date: 1999-06-08
Publication date: 1999-12-16
Anticipated expiration: 2000-12-10
Also published as: AU4408699A

Abstract

Blends of alkyl polyglycosides and alkyl sulfates are useful as wetting agents and textile pretreatment penetrants in baths containing high concentrations of alkali metal hydroxides.

Description

ALKYL POLYGLYCOSIDES AND ALKYL SULFATES AS PENETRANTS IN MERCERIZING BATHS

Background of the Invention

Field of the Invention

This invention relates to the use of blends of alkyl polyglycosides with various alkyl sulfates as wetting agents and textile pretreatment penetrants in baths containing extremely high concentrations of caustic soda, and more particularly, for the mercerization of cotton yarn, knit goods and woven goods. The object of pretreating textiles is to free the textile materials, yarns or flocks in a simple and careful manner from impurities which interfere with various treatment processes, such as dyeing, printing, optical brightening or finishing. In dyeing, for example, the pretreated material must not contain any troublesome quantities of soil, finishes, sizes and natural fiber impurities. At the same time, the material must have a sufficient degree of whiteness, uniformity, high dye- ability and absorbency. Synthetic sheet-form textile materials or yarns generally contain spinning finishes, size and soil which should be removed by washing processes. Natural textile materials and yarns are much more difficult to free from troublesome impurities, such as size, finishes, waxes, pectins, etc. In addition to desizing, alkaline scouring is mainly used for this purpose. Desizing and bleaching are suitable pretreatments for synthetic and/or natural fibers, but are generally applied to natural fibers either individually or in combination with alkaline scouring. In the above-mentioned pretreatments, namely washing, alkaline scouring, desizing and bleaching, the textile material is first contacted with a chemical liquor containing surfactants.

Mercerization is a customary step in the processing of cellulose- containing fiber materials and consists in treating these materials with aqueous alkali metal hydroxide. Mercerization wetting compositions must meet various application requirements. On the one hand, they must develop adequate wetting power in the strongly alkaline mercerizing liquors. Since in high-speed mercerizing machines the material to be mercerized moves through the liquor at high speed, it has to be wetted within a shorter time than is the case in machines working at slower speed. The higher speed of the material to be mercerized is responsible for increasing foaming on the liquor, which for example in yarn mercerization prevents not only rapid but also uniform wetting of the yarn. A further criterion for a good mercerization wetting composition is therefore the prevention of foaming in the mercerizing liquor. Furthermore, the formation of voluminous foam layers also interferes with the concentrating and recovery of the alkali metal hydroxide in the wash baths following the mercerizing bath.

Mercerization imparts to cellulose fibers for example higher luster. At the same time, their dye affinity and the breaking strength are improved. These fibers are for this purpose treated with concentrated alkali metal hydroxide solutions (about 22 to 28%), for example aqueous solutions of lithium, sodium or potassium hydroxide or mixtures of these hydroxides. In the process, the fibers can be subjected to a simultaneous drawing step, which makes it possible to achieve a further increase in the luster effect. The most frequently employed variant is cold mercerization (in contradistinction to hot mercerization, which is carried out at a bath temperature of 20°-80°C); In cold mercerization, the bath temperature is from about -20° to +20° C. Special effects, for example transparency effects, can be obtained by using baths cooled down to -20° C. Preferably, however, the temperature is 5° to 20° C. Depending on whether the fibers are mercerized in the dry, prescoured or prewetted state, the mercerization is known as dry or wet mercerization. Especially the variant of dry mercerization understandably makes the use of highly effective mercerization wetting compositions necessary.

Discussion of Related Art

By virtue of their biological compatibility and their known wetting properties, alkyl glycosides have recently been used to an increasing extent in domestic detergents. However, surfactants for the pretreatment of textiles have to meet far more stringent requirements than domestic detergents. Thus, surfactants for the pretreatment of textiles must have a higher resistance to chemicals and heat and, in addition, have to separate more and, above all, other troublesome impurities from the textile materials, yarns and flocks than soil, such as sizes, finishes, pectins, etc., in a shorter time.

One such attempt to provide a mercerization wetting composition is disclosed in U.S. Patent 5,464,547 which employs carbohydrate-based materials such as alkyl glycosides or alkyl carboxamidoglycosides. In addition, EP-A-0 102 930 discloses mercerization wetting compositions which are based on sulfuric esters of fatty alcohols and which are not only high-wetting but also low- foaming in use. Unfortunately, these wetting compositions are less advantageous from an ecological point of view, since they are slow to biodegrade.

The problem addressed by the present invention was to provide a surfactant-containing composition suitable for the pretreatment of textiles which would be resistant to chemicals and alkalis, would have a high wetting and dispersing power and would provide the treated textile materials with excellent absorbency and, in combination with a bleach, with a high degree of whiteness. In addition, the surfactant-containing composition would be ecologically safe, i.e. would be non-toxic and completely biodegradable in a short time.

Description of the Invention

This problem has been solved by the use of alkyl glycosides corresponding to general formula I

R¹ - O - (G)_n (I) in which R is a C₈.₁₄ alkyl radical, G is a glycose unit and n is a number of 1 to 3, in combination with various alkyl sulfates as surfactant-containing compositions in the mercerizing of cotton sheet-form textile materials, yarns or flocks.

In the context of the invention, sheet-form textile materials are understood to be woven and knitted fabrics and nonwovens. The textile pretreatment encompasses washing, alkaline scouring, bleaching and desizing. The term alkyl glycosides is intended as usual to apply to alkyl monoglycosides (n = 1 ) and to mixtures thereof with alkyl oligoglycosides having a degree of oligomerization n of no higher than 3.

The alkyl glycosides used in accordance with the invention are compounds known per se the production of which is described in numerous publications, for example in U.S. Patents 3,547,828, 3,772,269 and 3,839,318, in European patent applications EP 301 298, EP 357 969 and EP 362 671 and in DE-OS 39 27 919. The reaction products of glycoses and alcohols referred to as alkyl glycosides may be prepared either by direct reaction with an excess of the alcohol and an acid as catalyst or by transacetalization using a lower alcohol as solvent and reactant. The alkyl glycosides used in accordance with the invention are reaction products of the glycoses glucose, fructose, mannose, galactose, talose, gulose, allose, altrose, idose, arabinose, xylose, lyxose and ribose and alcohols containing 8 to 14 carbon atoms wherein the glycoses may be attached to one another by glycoside bonds. The number of glycoses attached to one another is characterized by the so-called degree of oligomerization which is denoted as n in general formula I. As an analytically determined value, the degree of oligomerization n may also be an uneven number. It is generally between 1 and 3 and, more particularly, between 1.1 and 1.4. The glycose units derived from the glycoses mentioned are denoted by the letter G in general formula I. In the context of the invention, G is preferably derived from glucose. R in general formula I is an alkyl radical containing 8 to 14 carbon atoms. R¹ is best derived from linear alcohols containing 8 to 14 carbon atoms which, as fatty alcohols, can be obtained in known manner from renewable raw materials. It is also possible to use compounds corresponding to general formula I in which R¹ is a branched alkyl radical containing 8 to 14 carbon atoms which is derived from branched alcohols. The branched alcohols may be obtained, for example, as so-called oxoalcohols by oxosynthesis. R¹ may of course also represent mixtures of alkyl radicals containing 8 to 14 carbon atoms. Mixtures such as these may be derived in particular from mixtures of linear alcohols containing 8 to 14 carbon atoms typically encountered in oleochemistry. Alkyl glycosides corresponding to general formula I in which R¹ is a linear alkyl radical containing 8 to 12 carbon atoms, are preferred for the purposes of the invention. Alkyl glycosides corresponding to general formula I in which R¹ is a linear alkyl radical essentially containing 10 carbon atoms, are particularly preferred. In the context of the invention, the term "essentially" in this connection means that 80 to 100% of R¹ represents the n-decyl radical. Accordingly, R¹ may be derived from alcohol mixtures which contain n-decyl alcohol in quantities of 80 to 100% by weight and an alcohol containing 8 to 14 carbon atoms and preferably 8 carbon atoms in quantities of 0 to 20% by weight. Alkyl glycosides corresponding to general formula I in which G is a glucose unit, n is a number of 1.1 to 1.4 and R¹ is a linear alkyl radical essentially containing 10 carbon atoms, are most particularly preferred.

From their production, the alkyl glycosides to be used in accordance with the invention may contain small quantities, preferably below 2% by weight, of unreacted alcohols containing 8 to 14 carbon atoms, although this does not adversely affect their use.

The alkyl glycosides may readily be used in the form of solutions or dispersions in the pretreatment liquors. Water and/or organic solvents, above all n-butanol, 2-ethyl hexanol and/or glycerol, may be used as solvents or dispersants. Aqueous solutions or aqueous dispersions of alkyl glycosides, which contain water in quantities of 50 to 100% by weight as solvent or dispersant and organic solvents in quantities of 0 to 50% by weight, based on solvent and dispersant, are preferred. Aqueous dispersions of alkyl glycosides are also understood to include the products known to the expert as "pastes". In general, the alkyl glycosides are used in the form of solutions or dispersions in such quantities that the active substance content of alkyl glycoside in 1 liter of the corresponding pretreatment liquor is in the range from 0.1 to 10 g. per liter. The alkyl sulfates, also known as fatty alcohol sulfates, employed with the alkyl glycosides in the pretreatment compositions of this invention correspond to general formula II

R - CH₂ - O - S0₃ Na (II) in which R is a C₆.₈ alkyl radical. Preferably, the fatty alcohol sulfates employed in the composition of this invention are selected from the group consisting of 2-ethylhexyl sulfate and n- octyl sulfate, sodium salt.

The alkyl glycosides and alkyl sulfates employed in this invention may be present in a weight ratio of from about 80:20 to 20:80, preferably in a weight ratio of from about 60:40 to 40:60.

According to the invention, the surfactant combination is preferably used for the bleaching of natural or synthetic sheet-form textiles, yarns or flocks and, more particularly, for the aqueous alkaline bleaching of cotton, cotton/polyester, cotton/polyacrylonitrile, cotton/viscose or cotton/polyamide. The bleaching liquors contain as bleaching agent hydrogen peroxide or compounds which form hydrogen peroxide in water. The ph value of the bleaches is adjusted to at least 9 with alkalis, preferably sodium hydroxide and/or potassium hydroxide. The bleaching liquors typically contain, per liter, 5 to 100 ml 35% by weight hydrogen peroxide, 0.5 to 50 g. sodium hydroxide or potassium hydroxide, 2.5 to 50 ml stabilizers, more particularly sodium or potassium silicate solutions, 0.1 to 1.0 g. magnesium salts, more particularly magnesium sulfate, 0.5 to 10 g. sequestrants of the phosphorate, gluconate or polyacrylate type, more particularly phosphonates such as Securon® 540 (a product of Henkel KGaA), the balance to 1 liter being made up by water. Bleaching is carried out at temperatures of 20° C (cold bleaching) to 120° C (hot bleaching) and preferably at temperatures of 70 to 120° C. The use of the alkyl glycosides and alkyl sulfates in accordance with the invention for bleaching is distinguished on the one hand by very good liquor uptake, i.e., large quantities of bleaching liquor are absorbed by the sheet- form textile materials, yarns or flocks, and on the other hand by a very high degree of whiteness. In addition, the sheet-form textiles, fibers or flocks are characterized after bleaching in the presence of alkyl glycosides and alkyl sulfates by very high absorbency and by a high and uniform dye absorption capacity. For the alkaline scouring or mercerizing of cotton-containing sheet-form textile materials, yarns or flocks, preferably for pure cotton, the alkyl glycosides and alkyl sulfates are used in the form of aqueous solutions or dispersions in such quantities that the active substance content of alkyl glycoside is in the range from 0.25 to 7.5 g. per liter scouring liquor, and that of the alkyl sulfates is in the range from 0.1 to 7.25 g. per liter scouring liquor. The scouring liquors are generally alkalized to a pH value of 10 to 14. The alkyl glycosides and alkyl sulfates are used in admixture with 2 to 300 g. alkalis, preferably sodium hydroxide or potassium hydroxide, and 0 to 5 g. sequestrants of the above- described type, per liter scouring liquor. Alkaline scouring may be carried out in the usual way, preferably at temperatures of 95°C to 100° C. Very high liquor uptakes which allow short contact times can be obtained by the use of alkyl glycosides and alkyl sulfates for continuous scouring.

Additions of typical foam inhibitors, such as silicones, mineral oils or phosphoric acid esters, may be of advantage for continuous textile pretreatment processes.

In all textile pretreatments, the use of the alkyl glycosides and alkyl sulfates in accordance with the invention provides for very high liquor uptakes which in turn allow short contact times between the material to be treated and the pretreatment baths. In addition, the surfactant combination is readily biodegradable and contains no phosphates or phenols. Further, mercerization wetting compositions of the invention also permit a rapid and trouble-free recovery of the alkali metal hydroxide from the wash baths following the mercerizing bath. In the course of distillative removal of water from these baths to concentrate the alkali metal hydroxide to the alkali metal hydroxide content of the mercerizing bath, these mercerization wetting compositions have only a very minimal tendency to form a foam. The concentrated alkali metal hydroxide solution obtained can then be re-used in the mercerizing bath.

The examples which follow illustrate the invention without limiting it thereto. Parts and percentages are by weight, unless otherwise stated.

Example I

Desized, scoured cotton twill was impregnated, wet on wet, in a continuous laboratory machine with an aqueous liquor containing, per liter, 250 g. NaOH (100%). 1 to 5 g. alkyl glucoside having a degree of oligomerization (n) of 1.25 and obtained by direct synthesis from decanol and anhydrous glucose, and 1 to 4 g. of a sodium salt of an alkyl sulfate based on n-octanol or 2 ethylhexanol. The impregnation temperature was 70° F, and the liquor uptake was

60% owg (120% owg total - 60% original water content). After impregnation, the fabric was continuously held for 30 to 60 seconds, followed by washing and neutralization carried out in a continuous washing range with 4 to 6 washing compartments.

Evaluation

To determine the effect of the mercerization process, the fabric was tested using the AATCC Test Method 89-1994 "Mercerization in Cotton" which produces a Barium Number that is a measure of the degree of mercerization. The higher the Barium Number, the higher the degree of mercerization. The results are shown in Table 1.

Table 1 Treatment Barium Number

1. bleached, unmercerized 100.0

2. mercerized, sodium 2-ethylhexyl sulfate 125.9 3. mercerized, 80:20 sodium 2-ethylhexyl sulfate: 137.0

GLUCOPON^® 425 N 4. mercerized, 70:30 sodium 2-ethylhexyl sulfate: 140.7 GLUCOPON^®425 N

5. mercerized, 60:40 sodium 2-ethylhexyl sulfate: 151.8 GLUCOPON^®425 N 6. mercerized, 80:20 sodium N-octyl sulfate: 148.1

GLUCOPON^®425 N

7. mercerized, 70:30 sodium N-octyl sulfate: 140.7 GLUCOPON^®425 N

8. mercerized: 60:40 sodium N-octyl sulfate: 144.1 GLUCOPON^®425 N

Note: GLUCOPON^® 425 N is a C₈ - C₁₆ alkyl polyglucoside having a degree of oligomerization n of about 1.6.

Claims

What is Claimed is:

1. The process of treating textile materials comprising contacting said textile materials with a treatment composition containing alkyl glycosides corresponding to general formula I

R¹ - O - (G)_n (I) in which R¹ is a C₈.₁₄ alkyl radical, G is a glycose unit and n is a number of 1 to 3, and alkyl sulfates, corresponding to general formula II

R-CH₂-0-S0₃ Na (II) in which R is a C₆.₈ alkyl radical.

2. A process as in claim 1 wherein R¹ is a linear C₈.₁₂ alkyl radical.

3. A process as in claim 1 wherein in said alkyl glycosides corresponding to general formula I, n is a number of 1.1 to 1.4.

4. A process as in claim 1 wherein G is a glucose unit.

5. A process as in claim 1 wherein said alkyl sulfates are selected from the group consisting of 2-ethylhexyl sulfate and n-octyl sulfate.

6. A process as in claim 1 wherein said alkyl glycosides are present in the form of solutions or dispersions in such quantities that the active substance content per liter of treating liquor is in the range from 0.1 to 10 g.

7. A process as in claim 1 wherein said alkyl alycosides are present in the amount of 0.25 to 7.5 g. per liter of treating liquor and said alkyl sulfates are present in the amount of 0.1 to 7.25 g. per liter of treating liquor.

8. A process as in claim 1 wherein said alkyl glycosides and said alkyl sulfates are present in a weight ratio of from 80:20 to 20:80.

9. A process as in claim 1 wherein said treatment composition has a pH of from 10 to 14.

10. A surfactant composition for the mercerization of cotton, said composition comprising alkyl glycosides corresponding to general formula I

R-CH₂-0-S0₃Na (II) in which R is a C_6-8 alkyl radical.

11. A composition as in claim 10 wherein R¹ is a linear C_8-12 alkyl radical.

12. A composition as in claim 10 wherein in said alkyl glycosides corresponding to general formula I, n is a number of 1.1 to 1.4.

13. A composition as in claim 10 wherein G is a glucose unit.

14. A composition as in claim 10 wherein said alkyl sulfates are selected from the group consisting of 2-ethylhexyl sulfate and n-octyl sulfate.

15. A composition as in claim 10 wherein said alkyl glycosides and said alkyl sulfates are present in a weight ratio of from 80:20 to 20:80.