EP0507973A1

EP0507973A1 - Biodegradable compositions for use as textile softeners

Info

Publication number: EP0507973A1
Application number: EP91105635A
Authority: EP
Inventors: Alberto Cigognini; Carlo Nicora
Original assignee: Lamberti Fratelli SpA
Current assignee: Lamberti SpA
Priority date: 1991-04-10
Filing date: 1991-04-10
Publication date: 1992-10-14

Abstract

Biodegradable compositions are described comprising

a) at least one carbonic acid diester with aliphatic, saturated or unsaturated, linear or branched alcohols or with mixtures of them, said diester having an average molecular weight of between 100 and 330 daltons;
b) at least one surface active substance;
c) at least one condensation product of alkanolamines or polyamines with fatty acid;

said compositions being particularly suitable for use as softeners and/or lubricants for yarns or fabrics of textile material.

Description

A. Technical sector

This invention relates to biodegradable compositions for use as textile softeners; said compositions consisting of at least one carbonic acid diester, at least one surface active substance and at least one condensation product of an alkanolamines with a fatty acid.

B. Prior art

In the textile industry widespread use is made of chemical substances either as such or in suitable formulations to obtain particular effects of softness and slipperiness on textiles.
In the case of plain textile products, the application of softeners or products able to produce particular slipperiness in the fabric is necessary to give the textile article those sensorial characteristics particularly appreciated by the final user. In addition the application of these products simplifies sewing when making for example an article of clothing.
Said softness characteristics are wholly and conceptually different from those normally required in the working steps of threads and yarns, such as for instance during the spinning and weaving steps. Such requirements are evidenced e.g. in the USP 2.153.137 of Nov. 26, 1937. In fact, the lubrication and softening required in the yarn in order to be woven is completely different from the type of softness normally required on the market for a plain textile product. This is proved by the fact that the softeners most appreciated on the market as finishing products are based on silicones and have a chemical composition generally different from the one of the products employed in the spinning step, in which one of the essential characteristics, among others, is the possibility of scouring off, which is not typical for silicones.
To provide these softness characteristics, the most commonly used substances in the finishing are silicones, the amino-amido or imidazoline type products, waxes and paraffins.
In general, the use of wax and paraffin based formulations is restricted to just a few fibres (such as cotton) and in addition are considered to be products which are not able to give the fabric a particularly noble finish.
Formulations containing products of amino-amido, imidazoline or amino-ester type are generally considered to be good softeners. However they often require additions of silicone based products to give the fabric that particular degree of slipperiness which cannot be attained using amino-amido, imidazoline or amino-ester derivatives alone.
The silicones are typically emulsified with water, for example using non-ionic surfactants, and then sold at various concentrations. They can also be used as additives for organic softeners of amino-amido, imidazoline or amino-ester type.
It is therefore apparent that the most valid and versatile products for use as softeners are those containing silicone.
However the ever increasing problem for the user of a silicone-containing formulation is the low or zero biodegradability of silicone polymer with the consequent problems of waste disposal.
Data regarding the low or zero biodegradability of silicones can be found for example in:

"Health and environmental aspects of polydimethylsiloxane fluids", J.C. Calandra et al.
Polymer Preprints 17 (1), 12 (April 1976).

In the present text biodegradable compositions are defined as all compositions having a biodegradability exceeding 60% based on the most common methods used to determine biodegradability.

C. Technical problem

Continuous research is therefore underway on new products which provide effective softening of the textile products to which they are applied while at the same time being biologically degradable in order to reduce the degree of pollution of the effluents into which they are discharged when the textile articles to which they have been applied are washed.

D. Detailed description of the invention

According to a fundamental characteristic of the present invention it has now been found that softener or lubricant compositions totally free of silicone substances have fabric softening characteristics very similar to the ones of silicone based compositions, with the advantage of being easily biodegradable thus avoiding environment pollution.
Said compositions comprise:

a) at least one carbonic acid diester with aliphatic, saturated or unsaturated, linear or branched alcohols or with mixtures of them, said diester having an average molecular weight of between 100 and 330 daltons;
b) at least one surface active substance;
c) at least one condensation product of alkanolamines or polyamines with fatty acid.

The preferred carbonic acid diesters for forming the compositions according to the invention are those in which the esterified alcoholic part consists of C₁₂-C₁₅ aliphatic alcohols.
The surface active substances typically suitable for the preparation of the invention's compositions are anionic, non-ionic or cationic surfactants, or mixtures of them within the limits of their mutual compatibility. In particular, sulphonated paraffins, alcohol sulphates, alkylbenzosulfonates, aliphatic sulphate esters, alkali salts of mono- or dialkyl phosphoric esters, alkali salts of phosphonic mono-esters, condensation derivatives of ethylene- and/or propylene oxide with alcohols, acids, hydroxyacids, hydroxy esters, alkylphenols, primary or secondary alkylamines which may be quaternarized with alkylating agents, in particular with dimethyl sulphate, benzyl chloride, dimethyl carbonate, or tertiary alkylamines quaternarized with alkylating agents.
The alkanolamines or polyamines condensed with fatty acid typically suitable for the preparation of the compositions of the present invention are ethanolamine, diethanolamine, triethanolamine, ethylendiamine, diethylen-triamine, triethylen-tetramine, amino-ethyl-ethylendiamine, N-alkyl-propylen-diamine, while the preferred fatty acids are stearic, oleic and palmitic acid.
The above cited components, which are essential for the formulation which is an object of the present invention show, however, high biodegradability. .
On the other hand, silicones, as already said, are not biodegradable and lead therefore to serious accumulation phenomena.
In the compositions according to the present invention the ratio between the carbonic acid diester and the other substances in the composition is typically of between 1:1 and 1:4 by weight (dry basis).
Said compositions may be in the form of emulsions or of auto-emulsionable solids.
In the case of emulsions, the stability of the emulsion is of fundamental importance for the use of the product.
In fact, it is necessary that the obtained emulsion be stable for a time sufficient to allow of a normal storage time, and that it may be able to stand the particular conditions of the selected use. In particular, the behaviour of the emulsion vis-a-vis thermal shocks, turbulence and mechanical stress is of fundamental importance.
It may further be necessary to add to emulsions small amounts of antifermentation substances. This addition, generally of between 1 and 10 ppm, is necessary to avoid the formation of molds, particularly in case of protracted storage at temperatures in excess of 30°C.
In these emulsion compositions the weight ratio between surface active substance and carbonic acid diester is comprised between 1:2 and 1:4 and the water contents is typically comprised between 50 and 80% of the composition weight.
In case of solid auto-emulsionable products, it will be necessary, when the product is emulsionated, that all the above mentioned characteristics, typical for a product in emulsion be reproduced. Besides providing softness, slipperiness and lubrication effects analogous to those provided by silicone-based formulations, the compositions of the invention are biodegradable and have an imbibition power higher than silicone-based formulations.
Some examples of compositions according to the invention and their properties in textile applications are described hereinafter.

EXAMPLE 1

8 g of dialkyl carbonate with a mainly linear C₁₂-C₁₅ alkyl chain, 0.7 g of a castor oil condensed with ethylene oxide (Emulsifier 40, Fratelli Lamberti SpA) and 1.2 g of an ethoxylated aliphatic linear alcohol (AE3 Ether, Fratelli Lamberti SpA) are fed into a suitable container provided with a stirrer system.
It is known that the above dialkyl carbonate ester has a biodegradability of at least 74% when determined according to the modified biotic degradation OCSE method n. 301 E.
Stirring is commenced and 23.4 g of water are added over a period of about 20 minutes. While stirring, 66.7 g of Texamina C1 liquid (a water-dispersed amino-amido condensation product of L. Lamberti SpA) are added.
The product obtained was applied to white cotton test pieces of size 20 x 40 cm, by foulard operating under the following conditions: 30 g/l of the aforesaid formulation, impregnation at 25°C on dry material, 98% wringing effect.
The fabric was then dried at 90°C for 15 minutes and then evaluated in comparison with cotton fabric test pieces treated with products containing about 8% of silicone.
The following table shows the compositions of the two formulations compared. TABLE 1

A B

Texamina C1 66.7 66.7

Emulsifier 1.9 1.2

Carbonic ester 8 -

Silicone 300 cP - 8

Water 23.4 24.1

$\bar{100.0}$
$\bar{100.0}$
The sensorial evaluation was carried our using the Panel Test (published in "La rivista delle sostanze grasse vol. LXIII, August 1986 page 439).
This evaluation shows that the formulation containing the carbonic acid diester gives the fabric the same characteristics in terms of slipperiness and softness as an analogous formulation containing about 8% of silicone as defined in Table 1.

EXAMPLE 2

The two formulations described in Example 1 were applied in the same manner to a PES/white cotton (35/65) fabric.
The test pieces were judged by the Panel Test to evaluate their slipperiness and softness. There were again no differences between the fabrics finished with the product containing carbonic acid diester and those containing silicone.

EXAMPLE 3

74 g of dialkyl carbonate with mainly linear C₁₂-C₁₅ alkyl chains, 4 g of an ethoxylated amine (Lamegal SD 70, Fratelli Lamberti SpA), 21 g of an ethoxylated aliphatic linear alcohol (AE3 Ether, Fratelli Lamberti SpA) and 1 g of an ethoxylated amine (Algin T/88, fratelli Lamberti SpA) are fed into a suitable container provided with a stirrer system. This formulation is dispersed in water by stirring to obtain a 30% emulsion of active substance.
This emulsion is applied to white cotton test pieces of size 20 x 40 cm by foulard operating under the following conditions: 30 g/l of the aforesaid formulation, impregnation at 25°C on dry material, 98% wringing effect.
The fabric was then dried at 90°C for 15 minutes and then judged for slipperiness and softness in comparison with identical cotton test pieces treated under the same conditions with a silicone emulsion (Texamina Sil of Fratelli Lambert SpA). The comparison was made operating so to obtain the same percentage (dry basis) of softening composition on the cotton test pieces.
The evaluation was carried out using the Panel Test.
From this evaluation it emerged that the formulation stated in the example gives the cotton fabric slipperiness and softness characteristics lower than those imparted by formulations containing the polydimethylsiloxane.
However the formulation containing the dialkyl carbonate again has higher biodegradability than the formulation containing silicone.
This last example underlines once again how a dialkyl carbonate, formulated with an emulsionating system only, will have softening characteristics lower than the ones of polydimethylsiloxane also formulated only with emulsionating agents.
This experimental evidence further enhances the importance of a suitable formulation technique for carbonic acid diesters in the field of softeners.

Claims

Biodegradable compositions for use as textile softeners, totally free of silicone substances comprising
a) at least one carbonic acid diester with one aliphatic, saturated or unsaturated, linear or branched alcohols or with mixtures of them said diester having an average molecular weight of between 100 and 330 daltons;

b) at least one surface active substance;

c) at least one condensation product of alkanolamines or polyamines with fatty acid.
Biodegradable compositions as claimed in claim 1, characterised in that said carbonic acid diester has the alcoholic part consisting of C₁₂-C₁₅ aliphatic alcohols.
Biodegradable compositions as claimed in claim 1, characterised in that said surface active substance is an anionic, non-ionic or cationic surfactant, or mixtures of them within the limits of their mutual compatibility.
Biodegradable compositions as claimed in claim 3, characterised in that said surfactant is selected from the group consisting of sulphonated paraffins, alcohol sulphates, alkylbenzosulfonates, aliphatic sulphate esters, alkali salts of mono- or dialkyl phosphoric esters, alkali salts of phosphonic mono-esters, condensation derivatives of ethylene- and/or propylene oxide with alcohols, acids, hydroxyacids, hydroxy esters, alkylphenols, primary or secondary alkylamines which may be quaternarized with alkylating agents, in particular with dimethyl sulphate, benzyl chloride, dimethyl carbonate, and tertiary alkylamines quaternarized with alkylating agents.
Biodegradable compositions as claimed in claim 1, characterised in that the fatty acid condensed with alkanolamines or polyamines is stearic or oleic or palmitic acid.
Biodegradable compositions as claimed in claim 5, characterized in that said alkanolamines are selected in the group consisting of ethanolamine, diethanolamine, triethanolamine.
Biodegradable compositions as claimed in claim 5, characterised in that said polyamines are selected in the group consisting of ethylendiamine, diethylen-triamine, triethylen-tetramine, amino-ethyl-ethylendiamine, N-alkyl-propylen-diamine.
Biodegradable compositions as claimed in claim 1. characterised in that the ratio between said carbonic acid diester and the other substances in the composition is of between 1:1 and 1:4 by weight (dry basis).
Biodegradable compositions as claimed in claim 1. characterised in that the weight ratio between said surface active substance and said carbonic acid diester is comprised between 1:2 and 1:4.
Biodegradable compositions as claimed in claim 1. characterised by the fact of being in the form of oil-in water emulsions, with a water content of between 50% and 80% by weight of the total and the weight ratio between surface active substance and carbonic acid diester being comprised between 1:2 and 1:4.