Use of pro-liposome compositions in the textile finishing and process for preparing dyeing bath based on said pro-liposome compositions

Description

[0001] The present invention relates to the use of pro-liposome compositions in the textile industry, providing advantages in three processes necessary within the general finishing operations of the textile industry: bleaching, dyeing and smoothing.

[0002] The use of said pro-liposome compositions permits an economic saving in raw materials used and at the same time reduces the pollutant content of the system.

[0003] The invention also relates to the method of preparing dyeing baths which use said pro-liposome compositions to produce liposomes charged with the necessary dyes.

Background of the Invention

[0004] The preparation of dyeing baths for textile products known in the art is based on the application of dyes to general fibrous or film-like materials, in order to lend them the permanent colour required by the use of which they will be put.

[0005] The dyeing solution is prepared by dissolving or dispersing the dye in water at a temperature of approximately 100°C. The resulting mixture is then placed in contact with the material to be dyed. Although many molecules of the dye may adhere to the surface of the material when they come into contact with same, the dyeing is not carried out until the particles of dye penetrate the fibres or films.

[0006] Substances which do not colour the product to be dyed but which assist the dyeing process are added to the dyeing bath in order to make the dye penetrate into said fibres or films. Most of these substances act by opening the structure of the fibre so that the dye molecules can enter more easily and reach zones which would otherwise be inaccessible.

[0007] One of the substances habitually used to boost the dyeing method is sodium sulphate. This is a water-soluble hygroscopic compound which is used for its surfactant properties.

[0008] The disadvantage of utilization of sodium sulphate is that it forms soluble salts which contaminate the water.

[0009] Also used for the same purpose are synthetic dye supplements which together with the sodium sulphate accelerate the dyeing by dispersing dissolving the dye, thus achieving homogeneity of colour in the fibres of the fabric to be dyed.

[0010] A quantity of a strong acid, such as sulphuric acid, is added to the bath to make the dye adhere to the fibre.

[0011] From this outline it emerges that in order to achieve suitable dyeing a sufficient quantity of dye and of sulphuric acid must be added to the bath, so that after the dyeing the residual bath containd large dissolved quantities of dye and of sulphates.

[0012] It can thus be observed that in the known dyeing methods the obtained residual bath is highly pollutant, owing to which such baths must be treated before discharge thereof to the exterior. Moreover known dyeing methods are carried out using highly specialized equipment and procedures which complicates large scale manufacture and makes industrial applications extremely expensive.

[0013] Also known are applications of liposomes as membrane models, drug vehicles and vaccine adjuvants and other applications in the field of genetics, foodstuffs and cosmetics.

[0014] The compositions of the liposomes can vary in function of their application, but in general they are made up of phospholipids.

[0015] Phospholipids are amphiphilic molecules since they have a polar head, the choline group in the case of phosphatidylcholine and two hydrophobic tails of 14 to 18 atoms of carbon each, whose origin are fatty acids.

[0016] In the presence of water, these molecules tend to group together spontaneously to form spherical lipidic double layers, in such a way that said hydrophobic tails are arranged inside the double layers and the polar heads on the exterior, interacting with the water. The said resulting structure is called liposome.

[0017] At present the methods for obtaining and applying liposomes are mostly carried out on a pilot scale or in laboratories. In order to resolve this problem, research has been carried out into the preparation of pro-liposome compositions which permit liposomes to be obtained with substances incorporated into them a few moments before utilization.

[0018] The pro-liposome compositions have been applied in the pharmaceutical and cosmetics field, as described in European patent EP-0 158 441 B1. That patent describes a pro-liposome composition which includes a uniform mixture of at least one membrane lipid, at least one water-miscible organic solvent and a quantity of water, the weight ratio between the membrane lipid and the water-miscible organic solvent being between 40:1 and 1:20.

[0019] In 1994 a new application of liposomes to the dyeing of wool fabrics was made known by Dr. J.L. Parra of C.S.I.C. However, this application of liposomes to fabric dyeing has the disadvantage of being a preparation with ready-formed liposomes obtained in a specialized laboratory.

[0020] Once formed, the liposomes have little stability for storage under the conditions prevailing in a textile factory (oxidizing atmosphere). In order to increase said stability, anti-oxidant substances must be added to the solution, which hinders the oxidizing degradation in the bath.

[0021] Furthermore, the liquid trapped inside the liposomes is the one which the manufacturer added during the formulation procedure of said liposomes. This is therefore a liquid prepared in advance and not suited to the requirements of the dye baths of the various textile industries.

[0022] Use of the resulting preparation leads to changed in the composition and the pH of the dyeing bath.

[0023] The result is that in the method described it is the liposomes manufacturer who decides what type of dye and the concentration to be incorporated into the preparation which includes liposomes.

DESCRIPTION OF THE INVENTION

[0024] The present invention resolves the said disadvantages, while at the same time providing advantages which will be described below.

[0025] The present invention relates to the use of pro-liposome compositions comprising a uniform mixture of at least one membrane lipid, at least one water-miscible organic solvent and an amount of water, the proportion by weight of the membrane lipid to the water-miscible organic solvent being from 40:1 to 1:20, for the preparation of dyeing, bleaching and smoothing baths in the textile industry.

[0026] Suitable membrane lipids are preferably phospholipids, for example natural lecithins such as soya lecithin, rapeseed, sunflower and synthetic lecithins such as dipalmitoylphosphatidyicholine. Glycolipids can also be used. Preferably, the phospholipids used are phosphatidylcholine, phosphatidylethanolamine and phosphatidylinositol.

[0027] Preferably, the vegetable composition comprises from 35% to 45% of a complex of phospholipids, glycerol (2% to 15%), an alcohol which can be ethanol, methanol or isopropanol (10% to 20%), the remainder being demineralized water. Alternatively, the composition may comprise phospholipids, a water soluble carrier, which can be a carbohydrate or any other water soluble solid substance.

[0028] Use of the pro-liposome composition permits preparation of the liposomes at the right time, such as when preparing the dyeing, bleaching or smoothing bath, thus ensuring the stability necessary for the liposomes to develop their humectant capacity and transport the ayes or substances which charge the interior of the fabric.

[0029] The dyeing and bleaching procedures preferably use a proportion by weight of pro-liposome composition to textile fabric of 0.05:100 to 1.5:100, while for the smoothing method the same proportion by weight is used, but relating to 100 kg of water instead of 100 kg of fabric.

[0030] One advantage of use of said pro-liposome composition is that it presents great stability under the storage conditions of a textile industry (oxidizing atmosphere). As the liposome forms at the desired time it is not necessary to add anti-oxidant substances to the dyeing solution to maintain the stability of the liposomes.

[0031] The application of liposomes lends the dyeing method greater efficacy, due to the greater penetration of the dye into the fabric fibres.

[0032] In the bleaching operation or phase the pro-liposome composition does not displace any other component, that is, the liposomes do not transport dye as in the dyeing operation, but are added to the bath because their humectant capacity facilitates peneration into the fabric, smooths it and enhances the final degree of bleaching.

[0033] In the smoothing phase, the addition of the pro-liposome composition to the bath permits partial or total substitution of the silicone and acetic acid normally used, thereby providing a saving in raw materials and reduction of the final pollutant content of the bath.

[0034] Use of the pro-liposome composition reduces the number of compounds usually employed in the dyeing bath and in the smoothing bath.

[0035] Use of the pro-liposome composition allows dyeing technicians to add the dyes or other desired compounds to the liposomes, thus exercising an effect on control of changes of composition and pH of the dyeing bath.

[0036] Furthermore, due to the efficacy of the dyeing method using the pro-liposome composition it is possible to reduce the temperature of the dyeing bath by 20°C (from 100°C to 80°), thus achieving, on the one hand, a 15% reduction of heating energy and, on the other hand, a reduction of processing time which also results in energy saving.

[0037] For the same reason, use of the pro-liposome composition in the textile industry dyeing process achieves a 20-40% reduction in the concentration of dye in the waste water.

[0038] The textile pro-liposome composition performs well at industrial level across the entire range of colours, whether plain colour or three-colours. It also shows good performance with acid dyes and chrome-based dyes.

[0039] From a chemical point of view, when using the pro-liposome composition a lower concentration of the pollutant substances of the conventional process is added, substances such as the dyeing sulphates and acetic acid or bleaching levellers, so that the residual baths are less pollutant.

[0040] The pollutant content of the waste waters shows a 30% reduction of sulphates, an almost total disappearance of the residual dye in the bath, and a 10-20% reduction of the COD (amount of oxygen necessary to oxidize the residue present). It should also be taken into account that the phospholipids of the pro-liposome composition are biodegradable.

[0041] The invention also relates to a method of preparing dyeing baths for textile products using the pro-liposome composition. The method comprises the following steps:

(I) At ambient temperature, mixing the pro-liposome composition with the desirable dye(s) and pre-heated water;

(II) Stirring the mixture to homogeneity thereof, such that liposomes including dye(s) therein are spontaneously formed;

(III) Separately, mixing sulphuric acid and pre-heated water;

(IV) Mixing the mixtures obtained in steps (I) to (III);

(V) Carrying out the bath of the fabric to be dyed.

[0042] Preferably, Step (I) is carried out in three operations:

(i) Mixing the dye with the pro-liposome composition;

(ii) Stirring the mixture to homogeneity thereof; and

(iii) Adding pre-heated water.

[0043] Optionally, in step (I) the pro-liposome composition and the dye(s) or other substances used are mixed in an alcohol medium prior to adding the pre-heated water, as this improves the solubility of the latter in said medium.

[0044] Preferably, in step (III) a portion of the total pro-liposome composition is added. Alternatively liposomes prepared from mixing the pro-liposome with pre-heated water are blended with all ingredients of the bath and the textile is being pretreated for a short time before addition of the dye. As a result part of the liposomes formed have a conditioning effet on the textile improving fixation of the dye to the fabric surface.

[0045] The use of pro-liposome compositions for the formation of liposomes provides good results in the following processes: in bleaching, as their humectant action permits better performance; in dyeing, as the dye is charged and transported, rendering possible more ecological and cheaper dyeing; and in smoothing, where silicones or smoothing products and acetic acid can be replaced totally or partially. In the three processes, it presents dual economic-ecological advantages.

[0046] The pro-liposome composition is effective in fabric dyeing processes, showing an improvement in smoothness to the touch of fabrics treated with liposomes compared with fabrics obtained by the usual method, since liposomes perform excellently in the smoothing phase, totally or partially replacing the silicones which are used in conjunction with acetic acid. Thus the bleaching operation using the pro-liposome composition, in addition to improving the quality of the end product, does not increase the pollution of the bath.

[0047] The smoothing method shows increased smoothness to the touch of the fabric when the pro-liposome composition is used.

[0048] The pro-liposome composition also provides the advantage of being easy to handle, since the phospholipids are less dangerous to handle than the other products mentioned, such as the silicones, acetic acid, sulphuric acid, etc.

[0049] In conclusion, use of the pro-liposome composition permits, on the one hand, the implementation of lower-cost, less polluting dyeing methods which lend the end product better quality, and on the other hand, it permits the introduction of state-of-the-art methodology in the textile industry without the need for any additional technological infrastructure.

[0050] For a better understanding of the above description, some non-limiting examples of embodiments of the invention are now set out.

EXAMPLES

[0051] Below is a description of three dyeing methods carried out on 100 kg of untreated wool. The fabric dyeing methods are carried out using the following compositions:

Composition 1

[0052] 

Sulphuric acid	3 kg
Pro-liposome	0.05 kg
Solid dye	0.221 g of yellow
	0.043 g of Bordeaux
	0.050 g of blue
Water	1,500 liters

Composition 2

[0053] 

Sulphuric acid	3 kg
Pro-liposome	0.1 kg
Solid dye	0.221 g of yellow
	0.043 g of Bordeaux
	0.050 g of blue
Water	1,500 liters

Method 1

[0054] This example describes the process to be followed for dyeing 100 kg of wool using composition 1.

[0055] The mixture of solid colorant is added to 0.05 kg of the pro-liposome composition.

[0056] The mixture is stirred and diluted in 10 liters of water pre-heated to 70°C. It is stirred again until a homogeneous mixture is obtained.

[0057] In this step of the method, approximately half of the dye added initially is encapsulated inside the liposomes formed; the remainder will reinforce the dyeing by its presence in the continuous phase of the dyeing bath.

[0058] Separately, the sulphuric acid is mixed with the rest of the water pre-heated to 80°C; the mixture of dyes and pro-liposome composition is then added to said mixture.

[0059] The dyeing bath is then implemented until the desired colour and shade are achieved. This step can be implemented in a time shorter than that required by the usual dyeing method.

[0060] Once the dyeing is finished, the remains of dye present in the fabric are eliminated by washings with cold water. The fabric is then drained off and dried.

Method 2

[0061] This example describes the process to be followed for dyeing 100 kg of wool using composition 2.

[0062] The mixture of solid colorant is added to 0,05 kg of the pro-liposome composition.

[0063] The mixture is stirred and diluted with 10 liters of water pre-heated to 70°C. It is stirred again until a homogeneous mixture is obtained.

[0064] In this step of the method, approximately half of the dye added initially is encapsulated inside the liposomes formed; the remainder will reinforce the dyeing by its presence in the continuous phase of the dyeing bath.

[0065] Separately, the sulphuric acid is mixed with the rest of the water pre-heated to 40°C and a further 0.05 kg of pro-liposome composition is added.

[0066] The temperature of the bath is increased to 80°C and the initial mixture of dye and pro-liposome composition is added, with total addition at this point in the method of 0.1 kg of pro-liposome composition.

[0067] The dyeing bath is then implemented until the desired colour and shade are achieved. This step can be implemented in a time shorter than that required by the usual dyeing process.

[0068] Once the dyeing is finished, the remains of dye present in the fabric are eliminated by washings with cold water. The fabric is then drained off and dried.

[0069] The preferable concentration by weight of pro-liposome composition is 0.05% of the fabric to be treated.

Method 3

[0070] This example describes the process to be followed for dyeing 100 kg of wool using compositon 2.

[0071] The pro-liposome is mixed with 2 litres of water pre-heated to 70°C. It is stirred until a homogenous mixture is obtained.

[0072] Thus a concentrated suspension of empty liposomes is obtained.

[0073] This mixture is then added to the total of the textile bath.

[0074] After approx. 10 Min. of textile pretreatment with this liposome suspension a concentrated dye solution is added.

[0075] The dyeing process is then continued until the desired colour and stade is achieved.

Comparative results of the usual dyeing method and that using the pro-liposome compositon

[0076] Comparative tests have been carried out before and after the dyeing using the usual dyeing method and the pro-liposome composition. It was observed that the fabric absorbs a greater quantity of dye when the pro-liposome composition is used than when the usual method is used. This leads, on the one hand, to better fabric dyeing quality and, on the other hand, to less quantity of dye in the residual bath.

[0077] Following analysis of the residual bath after the dyeing it is observed by way of example that use of the pro-liposome composition reduces the pollutant content of sulphates and the charge necessary to oxidize the residue present (COD).

Analysis parameters	Usual meth.	Meth. with pro-liposome composition
COD	1,659 mg/l	1,035 mg/l
Sulphates	3,549 mg/l	2,717 mg/l

[0078] Use of the pro-liposome composition also provides a saving of the raw material used for dyeing 100 kg of fabric.

Raw material	Usual: kg needed	Prolip. needed
Sulphuric acid	3	3
Anhydrous sodium sulphate	7.5	--
Arolan SCN 150 (leveller)	0.3	--
Pro-liposome	--	0.05

[0079] Also enclosed is a comparative example of the energy consumption for the dyeing of 100 kg of fabric using the usual dyeing method and the one using the pro-liposome composition of the invention.

Temperature	kg of steam	Cost difference
Usual proc. 100°C	15.44 kg
Proc. with pro-liposome 80°C	13 kg	2.44 (15.58%)

[0080] It can se observed that use of the pro-liposome composition provides a comparative energy saving of 15.58% with respect to the energy expenditure using the usual dyeing method.

[0081] In respect of the smoothing method, two examples are attached showing smoothing by mellowing, which examples do not restrict the scope of the invention.

Example of smoothing 1

[0082] Firstly, a solution is prepared containing 0.75 kg of pro-liposome composition and 1,500 1 of water at ambient temperature. 100 kg of fabric is then submerged in the solution prepared, and this is left for the time necessary for incorporation of the smoothing agent, that is, the formed liposome, and therefore for depletion of the bath.

Example of smoothing 2

[0083] Firstly, a solution is prepared containing 1.5 kg of pro-liposome composition and 1,500 1 of water at ambient temperature. 100 kg of fabric is then submerged in the solution prepared, and this is left for the time necessary for incorporation of the smoothing agent, that is, the formed liposome, and therefore for depletion of the bath.

[0084] As a result of all the above it can be deduced that pro-liposome is a highly versatile transporter which is capable of charging and delivering a wide range of substances: dyes, smoothing agents, etc. The mechanism of liposome formation by charging a substance is summarized as follows: to the pro-liposome composition or to the water (depending on the case) must be added the substance to be encapsulated and transported; with the addition of water there form spontaneously the liposomes which will contain said substance inside them.

[0085] Utilization thereof permits access to or use of a cleaner technology and the introduction of a process methodology which requires no investment or infrastructure.

Claims

1. Use of pro-liposome compositions comprising a uniform mixture of at least one membrane lipid, at least one water-miscible organic solvent and an amount of water, the proportion by weight of the membrane lipid to the water-miscible organic solvent being from 40:1 to 1:20, for the preparation of dyeing, bleaching and smoothing baths in the textile industry.

2. Use according to claim 1, wherein said composition comprises from 35% to 45% of a complex of vegetable phospholipids, from 2% to 15% of glycerin, from 10% to 20% of an alcohol, the remainder being demineralizated water.

3. Use according to claim 2, wherein the alcohol is ethanol, methanol or isopropyl alcohol.

4. A method of preparing dyeing baths in the textile industry from pro-liposome compositions comprising a uniform mixture of at least one membrane lipid, at least one water-miscible organic solvent and an amount of water, the proportion by weight of the membrane lipid to the water-miscible organic solvent being from 40:1 to 1:20, wherein said method comprises the following steps:

(I) Mixing the pro-liposome composition with the desirable dye(s) and pre-heated water;

(II) Stirring the mixture to homogeneity thereof, such that liposomes including dye(s) therein are spontaneously formed;

(III) Separately, mixing sulphuric acid and pre-heated water;

(IV) Mixing the mixtures obtained in steps (I) to (III);

(V) Carring out the bath of the fabric to be dyed.

5. A method according to claim 4, wherein the step (I) is caried out with the following operations:

(i) Mixing the dye with the pro-liposome composition;

(ii) Stirring the mixture to homogeneity thereof; and

(iii) Adding pre-heated water.

6. A method according to claim 4 or 5, wherein in step (I), the pro-liposome composition and the dye(s) are mixed in an alcohol medium prior to adding the pre-heated water.

7. A method according to claim 4 or 5, wherein in step (III) a portion of the pro-liposome composition is added.

8. A method according to claim 4, wherein the pro-liposome composition is mixed with pre-heated water to form empty liposomes and said empty liposomes are used to pretreat the textile prior to the addition of the dye.