FORM 2
THE PATENTS ACT, 1970
(39 of 1970)
&
THE PATENTS RULES, 2003
COMPLETE SPECIFICATION (See section 10, rule 13)
‘’CATIONIZING AGENT’’
(1) Ahmedabad Textile Industry’s Research Association (ATIRA) of Dr VikramSarabhai Marg, P O Ambawadi Vistar, Ahmadabad, India
(2) MICROMOLE IONICS Pvt Ltd of 306, Sukhsagar Complex, Nr Fortune Landmark, Ashram Road, Ahmedabad 380013, India
The following specification particularly describes the invention and the manner in which it is to be performed.

FIELD OF THE INVENTION
The present invention relates to textile and dyes. More particularly the invention relates an environmental friendly process for dyeing fiber/yarn/fabric. More particularly the invention relates to a cationizing agent and its application in pre-dyeing treatments to cellulosic textiles.
BACKGROUND OF THE INVENTION
With the growing popularity of reactive dyes for dyeing cellulosics, the environmental problems associated with their use have become a major concern. The reactive dyes being water soluble, large quantities of electrolytes such as sodium chloride or sodium sulphate [40-100 gpl] are normally required for their exhaustion. Despite this, the dye exhaustion is still as low as 50% for some dyes, in the normal range 50-75%. Besides, large quantity of caustic soda and /or soda ash is also used for dye fixation. The waste water from the reactive dyeing process therefore contains significant quantities of alkalinity, salts and the hydrolyzed dyes leading to serious environmental problems.
In effluent treatment plant, these three constituents impact heavily and make treatment difficult and costly. To neutralize alkali, huge quantity of acid is consumed thereby generating salt, which is undesirable. To remove color, huge quantity of chemicals are being used , which generate sludge , even though 100 % color removal is difficult. Hence, the total salt (generated due to alkali neutralization as well as the added salt for exhaustion) increases total dissolved solids in effluent , which inhibit bacterial activity in the biological treatment. With these constraints, the treatment plant becomes unduly large and costly with high operating costs. Hence it is desirable to minimize use of salt and alkali in dyeing processes.
The reactive dyes being anionic, the chemical modification of cellulosics to introduce cationic group offers a simple and effective method of improving dye-fiber affinity. This is not only true for reactive dyes but also for all anionic dyes including direct dyes. By virtue of enhanced dye-fiber affinity, the dye-exhaustion can take place avoiding/reducing the need for the salt. The amount of alkali required for dye –fixation can also be reduced.
Several varieties of cationizing agents for cellulosic fibre/textiles have been developed with the objectives of cationizing the cellulosic textiles which in turn facilitate the dyeing process. Possibly, the most common of them being 3-chloro-2-hydroxypropyltrimethyl ammonium chloride (QUART 188, Technical Data Sheet, Dow Chemical Company). The bonding with

the cellulosic hydroxy group is through oxirane moiety. Similarly, Dvorsky et al (US Patent 4499282) has claimed a cationizing compound capable of reacting with two hydroxyl groups of cellulose and thereby functioning as cationizing agent as well as imparter of cross linking effect. CIBAFIX WFF (Technical Data Sheet CIBA WFF, Ciba Speciality Chemicals) is a polyamino chlorohydrin quaternary ammonium compound, a dye fixing agent, which has also been evaluated as an effective cationizing agent (Kannan et al, J. Textile and Apparel Technology and Management, Vol. 5, issue 2 Summer 2006). In most of these developments, emphasis has been given on effectiveness of cationization, thereby, chemically attracting the anionic dyes (e.g. Reactive class of dyes) from the dye bath resulting in improved dye exhaustion and high color yield. Color fastness performances are also reported to be good in some of the cases. However, what is important for commercial exploitation of the product/technology is the levelness of the dyeing and non-deviation of the color tone with such cationizing treatment besides good fastness properties. The stereo chemical aspects of the cationizing moiety play a very important role. Such comparative results of dyeing with cationized textiles vis-à-vis the controlled one including relative environmental impacts are not available in any of the references mentioned above.
Thus, the inventors of the present invention have realised the role of cationizing agent in making dyeing possible without the use of salt and minimizing the use of alkali so that the total dissolved solids and alkalinity are minimized in the waste waters from the post -dye wash-offs. Further, the inventors of the present invention have also realised need of cationizing agent with favourable water solubility and stereo-chemical configuration so as to render effective dyeing of cellulosics with variety of anionic dyes.
OBJECTIVES OF THE INVENTION
The main objective of the present invention is to develop an environmental friendly process for dyeing fiber/yarn/fabric.
Another object of the invention is to provide a process for preparing modified cationizing agent.
Yet another object of the invention is to provide a cationizing agent endowed with multiple cationic sites and with optimum chlrohydrin moiety to achieve effective bonding with cellulose.
Yet another object of the invention is to provide a cationizing agent for modifying cellulosics without imparting stiffness and preserving the supple tactile.

Yet another object of the present invention is to provide a cationizing agent wherein the spatial arrangement of the cationic moiety is such that the approaching anionic dye molecule has an easy access to the cationic sites of the cationized cellulosic substrate.
Still another object of the present invention is to provide a cationizing agent which can be used to achieve dyeing without the use of salt and minimizing the use of alkali so that the total dissolved solids and alkalinity are minimized in the waste waters from the post - dye wash-offs.
SUMMARY OF THE INVENTION
The present invention relates to an environmental friendly process for dyeing fiber/yarn/fabric comprising the steps of; (a) treating fibers with a modified cationizing agent to induce more reactive sites on the fiber surface; wherein the modified cationizing agent is characterized as a reactive cationizing polymer (RCP) of amines and epichlorohydrine in the presence of crosslinking agent having viscosity in the range 200 to 1000 cps, the active polymer content in the range of 45-50% and pH in the range of 3 to 4; (b) dyeing the treated fibers of step (a) with anionic dyes such as reactive dye or direct dye or indigo dye or combination thereof without use of salt and 25-100% less alkali in the dyeing process; (c) washing of dyed fibers of step (b) to obtain desired dyed fiber/yarn/fabric. The present invention also relates to a process of making modified cationizing agent.
BRIEF DESCRIPTION OF THE FIGURES
Figure 1: represents FTIR of RCP, Solution in water taking water as a reference (full range); Figure 2: represents FTIR of RCP in the .range of 600-420 cm-1; Figure 3: represents FTIR of RCP in the range 1200-600 cm-1.
DETAILED DESCRIPTION OF THE INVENTION
While the invention is susceptible to various modifications and alternative forms, specific embodiment thereof has been shown by way of examples and will be described in detail below. It should be understood, however that it is not intended to limit the invention to the particular forms disclosed, but on the contrary, the invention is to cover all modifications, equivalents, and alternative falling within the spirit and the scope of the invention.

The Applicants would like to mention that the examples are mentioned to show only those specific details that are pertinent to understanding the aspects of the present invention so as not to obscure the disclosure with details that will be readily apparent to those of ordinary skill in the art having benefit of the description herein.
The terms “comprises”, “comprising”, or any other variations thereof, are intended to cover a non-exclusive inclusion, such that a process that comprises a list of components does not include only those components but may include other components not expressly listed or inherent to such process. In other words, one or more elements in a system or process proceeded by “comprises… a” does not, without more constraints, preclude the existence of other elements or additional elements in the system or process.
Accordingly, in one aspect the present invention relates to an environmental friendly process for dyeing fiber/yarn/fabric comprising the steps of; (a) treating fibers with a modified cationizing agent to induce more reactive sites on the fiber surface; wherein the modified cationizing agent is characterized as a reactive cationizing polymer (RCP) of amines and epichlorohydrine in the presence of crosslinking agent having viscosity in the range 200 to 1000 cps, the active polymer content in the range of 45-50% and pH in the range of 3 to 4; (b) dyeing the treated fibers of step (a) with anionic dyes anionic dyes such as reactive dye or direct dye or indigo dye or combination thereof without use of salt and with 25-100% less alkai; (c) washing of dyed fibers of step (b) to obtain desired dyed fiber/yarn/fabric.
In another aspect of the present invention the amines are selected from the group comprising of methyl amine, dimethyl amine, trimethyl amine, ethylene diamine, diethylene triamine, hexamethylene triamine or combination thereof.
In yet another aspect of the present invention, the crosslinking agents are selected from the group comprising of alkyl diamines and alkyl triamines such as ethylene diamine, diethylene triamine, hexamethylenediamine, bis(hexamethylene) triamine.
In yet another aspect of the present invention the modified cationizing agent is prepared by the process comprising the steps of; (a) reacting 1.5 – 2.5 mole dimethyl amine, 0.5 - 2.0 mole ethylene diamine, 1.7- 2.3 mole epichlorohydrine, wherein epichlorohydrine is added gradually with stirring and maintaining the reaction temperature below 25 °C; (b) adding 0.4

– 1.0 mole diethylene triamine or bis(hexamethylene) triamine and 0.2 – 0.5 mole epichlorohydrine portion wise in step (a), wherein temperature increased to 60 °C and reaction continued for 3 hours, thereafter reaction temperature further increased to 90°C under stirring for 30 minutes; (c) adding 3-4% soda ash of the total reaction mass and adding 0.4 – 0.8 mole epichlorohydrin which further increases the temperature of the reaction mass by 5 °C and allowed the reaction to continue to achieve the viscosity in the range 200 – 1000 cps; (d) acidifying the reaction mass by adding in step (c) sufficient quantity of hydrochloric acid to obtain pH in the range 4-6 to obtain cationizing agent for dyeing fiber/yarn/fabric.
In yet another aspect of the present invention, the fiber/yarn/fabric is treated/cationized by 5 to 300 gm/kg of fiber/yarn/fabric of cationizing agent and preferably by 5 to 50 gm/kg of fiber/yarn/fabric of the cationizing agent.
In yet another aspect of the present invention, the fibers are cellulosic fibers, wool, silk or their blends or combination thereof.
In yet another aspect of the present invention the residual dye liquor having TDS 3 - 5 times lesser, COD 2.5 – 3.5 times lesser and BOD 3-5 times lesser as compare to the control.
In yet another aspect of the present invention the first post dye wash off having COD 5 -10 times lesser and BOD 7-12 times lesser as compare to the control.
In yet another aspect it relates to the cationizing agent and its application in textile pre-dyeing treatments.
In yet another aspect the present invention relates to a cationizing agent which has increased cationic dye-combining sites in its configuration which can be used for chemical modification of cellulosics.
In yet another aspect the cationizing agent of the present invention has reduced number of reactive [welding] groups which helps in retaining softness in the textile material, since large number of welding points would impart stiffness to the cellulosic substrate, while chemical modification to introduce cationic groups. These reactive groups attach [weld] the

cationizing molecule to the cellulosic substrate in the chemical modification [Cationization] step.
In yet another aspect the cationizing agent of the present invention has a favourable stereo chemical configuration such that the accessibility of anionic dyes to the cationic group [which is welded to the substrate through wielding groups] is facilitated for the best dye-fiber interaction.
In yet another aspect the cationizing agent of the present invention also facilitates a deep penetrated chemical-modification, so as to achieve a deep-penetrated dyeing for all-round fastness of dyeing.
In yet another aspect the cationizing agent of the present invention is Reactive Cationic Polymer, which is a macromolecule.
In yet another aspect the reactive cationic polymer of the present invention is synthesised by condensation polymerization of combination of amines and epichlorohydrine. The amines used are selected but not limited to methyl amine, dimethyl amine, , ethylene diamine, diethylene triamine, and hexamethylene diamine and bis(hexamethylene) triamine. In order to design an appropriate macromolecule, proper combination of amines and extent of crosslinking are the key factors. Alkyl diamines and alkyl triamines are used as crosslinking agents. Additionally, soda ash & hydrochloric acid are also involved to facilitate the reaction and adjust the pH respectively. The final product has a pH in the range of 4-5 & viscosity in the range 200-1000 cps, the active polymer content being 45-50%.
An indicative process of synthesis of cationic macromolecule is given below:
Jacketed stainless steel (SS 316) vessel equipped with stirrer and condenser is charged with 284 liters with demineralised water, 273 kg [2427 gram mole] of dimethyl amine (40% aqueous) and 40 kg [600 gram mole]of ethylene diamine with agitator. 189 kg [2043 gram mole] of epichlorohydrine is then added gradually with stirring and cooling so as to maintain the reaction temperature below 25 degree centigrade. 44 kg of [427 gram mole] diethylene triamine was then added portion wise followed by 29 kg [313 gram mole] of epichlorohydrin. After complete addition, the temperature is raised up to 60 degree centigrade and the reaction is allowed to continue for 3 hrs. The reaction temperature is further raised to 90 degree centigrade, kept under stirring for 30 minutes and 22 kg soda ash is added and 48 kg [519

gram mole] epichlorohydrin is then added slowly and the temperature is further raised to 5 degree more. After attaining a desired level of viscosity (800 – 900 cps), the reaction is stopped by adding sufficient quantity of hydrochloric acid (pH 4).
In yet another aspect the reactive cationic polymer has built-in penetrant for deep penetrated & levelled fabric application. Each building block of the said reactive cationic polymer has multiple cationic dye-combining sites which attract anionic dyes and combine with anionic dyes and it welds itself to cellulosics hydroxyl group through oxirane moiety.
In other aspect of the invention the cationizing treatment is given to bleached/mercerized fabric, prior to dyeing. The treatment involves (a) treating with caustic soda, using 20 gram caustic soda per kg of fabric, to generate cellulosate ions. These cellulose anions are highly reactive / receptive towards cationic compounds, i.e. RCP (b) treatment with RCP, using 24 grams RCP (50% active) per kg of fabric; (c) thorough rinsing for neutralization in order to remove residual chemicals. All the treatments are carried out in jigger.
Both, RCP (50% active) and the cationized fabrics are subjected to Kjeldahl’s method of nitrogen estimation, to determine the nitrogen content. The results are shown in Table 1.
Characterization of Cationizing Agent Nitrogen estimation stoichiometry
The % of nitrogen is determined by Kjeldahl’s method in Reactive Cationizing polymer (RCP:50%active) and found to be 4.5 % nitrogen.
Table 1: % of Nitrogen content

Sample % Nitrogen content
RCP (50% active) 4.5
Cationized fabric
NaOH 20gm/kg of fabric
RCP (50% active) 24 gm/kg of fabric 0.1
Cationized fabric
NaOH 25gm/kg of fabric
RCP (50% active) 24 gm/kg of fabric 0.1
The nitrogen content of RCP (50% active) being 4.5 % and application of RCP (50% active) being 2.4% (24gram/kg of fabric), the theoretical nitrogen content of the cationized fabric

works out to be 0.108%. The experimentally found nitrogen content is 0.1 %. These results are indicative of 92-93 % utilization/fixation of RCP in the cationization treatment.
Infra-red spectrometry
Infra-red spectrometry
Infra-red spectra are obtained by using FTIR Spectrophotometer, Figure 1, represents full scale FTIR of RCP, solution in water taking water as a reference. Figure 2, represents FTIR of RCP in the range of 600-420 cm-1, showing characteristic peaks at 427 cm-1 & 463 cm-1 corresponding to C – N bending. Figure 3, represents FTIR of RCP in the range 1200-600 cm-1, showing characteristic peaks at : 1084 cm-1 , 1027 cm-1, 923 cm-1 & 859 cm-11 corresponding to C = O stretching vibration, N - H band, C - N stretch and hydrogen bonded amine/amide.
The following examples are presented to illustrate the present invention in detail:
Example 1
Cationization of cotton fabric with 50 gram per liter of cationizing agent
50 gm of reactive cationic polymer (RCP) solution (50% active) is dissolved in 800 ml water. 15 gm of caustic soda is dissolved in 135 ml water. Both the solutions are mixed together & ‘ready for dyeing’ cotton fabric is padded (70% expression), dried and cured at 130°C-110°C for 30 seconds to 3minutes. The fabric is then washed in jigger to make it neutral and is dried or dyed wet-on-wet.
Example 2
Cationization of cotton fabric with 75 gram per liter cationizing agent
75 gm of reactive cationic polymer solution (50% active) is dissolved in 800 ml water. 15 gm of caustic soda is dissolved in 110 ml water. Both the solutions are mixed together & ‘ready for dyeing’ cotton fabric is padded (70% expression), dried and cured at 130°C-110°C for 30 seconds to3minutes. The fabric is then washed in jigger to make it neutral & is dried or dyed wet-on-wet.
Example 3
Cationization of cotton fabric with 300 gram per liter cationizing agent

300 gm of reactive cationic polymer solution (50% active) is dissolved in 500 ml water. 15 gm of caustic soda is dissolved in 185 ml of water. Both the solutions are mixed together & ‘ready for dyeing’ cotton fabric is & padded (70% expression), dried and cured at 130°C-110°C for 30 seconds to 3 minutes. The treated & cured fabric is washed in jigger to make it neutral & then dried or dyed wet-on-wet.
The aforesaid cationization of cellulosics (including silk or wool) is also possible by pad-batch, and exhaust (jigger) methods in addition to pad-dry and cure method detailed above.
Example 4
Dyeing with reactive dye: reactive Blue HE
The fabric as prepared in Example 1 is dyed in 3% shade with reactive Blue HE following the standard dyeing route for HE reactive dyes. A control fabric is also dyed simultaneously in a separate bath to compare the results.
The recipes for both the treatments are as follows:
Recipe for control: Dye: reactive HE Blue, 3% shade, Glauber salt: 40 gpl, Alkali: 20 gpl.
Recipe for cationized fabric (fabric of example 1): dye: reactive HE Blue, 3% shade, Alkali: 6 gpl.
Water used for dyeing: pH: 7.04; Conductivity: 0.5; Total dissolved solids (TDS): 1344 ppm.
Identical Post-dyeing treatments (hot wash-hot wash -soaping-hot wash- hot wash -cold wash-dry) are given to both the fabrics.
The shades thus developed are evaluated using Spectrophotometer, (Datacolor SF 650, 10 degree observer, D65 illuminant)

L* 40.67
36.88 a* -13.24
-13.00 b* -34.50
-36.44 % R 7.88
6.12
Trial(cationized fabric)

Control

The values for a* and b* are found to be quite close and hence there is practically no tonal variation. The levelness of dyeing is very good. The target to achieve salt-free, less-alkali dying with acceptable fastness is achieved. Moreover, the objective of achieving matching shade (trial versus control) is also met with. For the matching-shade purpose, a cationization using 50 gpl cationizing chemical (Example 1) is adequate for salt free, less alkali dyeing. Higher degree of cationization leads to much darker shade (gimmick) but the shade matching would be an extra botheration which would restrict implementation in industry.
The fastness properties are tested and graded as follows:

Parameter Test Method Test Results Trial Sample Test Results Control
(cationized fabric) Sample
Colour fastness to Light ISO 105 B02 4-5 5
Colour fastness to washing IS 764 (60 4-5 4-5
Staining on adjacent degree
Polyester Celsius) 4-5 4-5
Cotton 4-5 4-5
Wool 4-5 4-5
Nylon 4-5 4-5
Acrylic 4-5 4-5
Acetate 4-5 4-5
Rubbing Fastness IS 766
Dry 4-5 4-5
Wet 4 4-5
Example 5
Dyeing with reactive dye: reactive Yellow HE
The fabric as prepared in Example 1 is dyed with Reactive Yellow HE following the standard dyeing route for HE colors. A control fabric is also dyed in a separate bath to compare the results.
The recipes for both the treatment are as follows:
Recipe for control: Dye: Reactive yellow HE 3% shade, Glauber salt: 40 gpl, Alkali: 20 gpl
Recipe for trial (fabric of example 1): Dye: Reactive yellow HE 3% shade, Alkali: 6 gpl

Identical post dyeing treatments are given to both the fabrics (hot wash-hot wash-soaping-hot wash-hot wash-cold wash-dry).
The shades thus developed are tested using Spectrophotometer, (Datacolor SF 650, 10 degree observer, D65 illuminant).

L*
78.45
76.22 a*
28.19
32.36 b*
84.02
85.73 % R
Trial


71.63
Control


69.19
The values for a* and b* are found to be quite close and hence there is practically no tonal variation. The levelness of dyeing is also very good.
The fastness properties are tested and graded as follows:

Parameter Test MethToeds t Results Test Results
Trial Cationized fabCroic Control Sample
Colour fastness ISO 105 B02 4-5 5
to Light
Colour fastness Is 764 4-5 4-5
to washing (60degree
Staining on Celsius)
adjacent
Polyester 4-5 4-5
Cotton 4-5 4
Wool 4-5 4-5
Nylon 4-5 4-5
Acrylic 4-5 4-5
Acetate 4-5 4-5
Rubbing IS 766
Fastness
Dry 4 4
Wet 4-5 4

Example 6
The residual dye - liquor & first post dyeing wash water in Example 4 are collected & tested as per the standard methods for the examination of water & waste water, (21st edition, prepared & published by APHA-AWWA-WPCF, USA & BIS methods).
The results are as follows:

Sample Description Results
pH Colou ( Co P Colour ( Co Pt) TDS (mg/L) COD (mg /L) BOD (mg/L)
Residual Dye liquor
Control
Trial 10.09 10.20 1495 2250 25946 5686 1248 392 541 127
First Post dye wash off
Control
Trial 8.61 8.39 245 85 1438 1348 344 40 110 <10
As the trial is with no salt dyeing, the TDS in the residual dye-liquor is significantly less compared to the control. The COD and BOD values are also comparatively low.
Example 7
The residual dye-liquor & first post- wash in Example 5 are collected & tested as per standard methods for the examination of water & waste water, (21st edition, prepared & published by APHA-AWWA-WPCF, USA & BIS methods).
The results are as follows:

Sample Description Results
pH Colou Colour (Co Pt) TDS (mg/L) COD (mg /L) BOD (mg/L)
Residual Dye liquor
Control
Trial 10.05 10.17 3410 4260 26962 5594 1706 264 569 87
First Post-dye wash-off
Control
Trial 8.66 8.48 320 145 1462 1234 88 48 <10 <10

As the trial was no salt dyeing, the TDS in the residual the dye-liquor was significantly less compare to the control. The COD and BOD values were also comparatively quite low.
Example 8
Cationization of cotton fabric with 5 gram per liter of cationizing agent
Recipe for cationization of fabric
5 gm of reactive cationic polymer solution (50% active) is dissolved in 800 ml water. 2.5 gm of caustic soda is dissolved in 135 ml water. Both the solutions are mixed together & ‘ready for dyeing’ cotton fabric is padded (70% expression), dried, and cured at 130°C-110°C for 30 seconds to 3minutes. The fabric is then washed in jigger to make it neutral and is dried or dyed wet-on-wet.
Recipe for control: Dye: reactive HE Blue, 1% shade, Glauber salt: 30 gpl, Alkali: 15 gpl.
Dye: reactive HE Blue, 0.5 % shade, No salt & No Alkali.
Water used for dyeing: pH: 7.04; Conductivity: 0.5; Total dissolved solids (TDS): 1344 ppm.
Identical post-dyeing treatments (hot wash-hot wash -soaping-hot wash- hot wash -cold wash-dry) are given to both the fabrics.
The shades thus developed are evaluated using Spectrophotometer, (Datacolor SF 650, 10 degree observer, D65 illuminant)

L* 66.32
65.17 a* -8.35
-8.14 b* -17.82
-17.46 % R 31.28
30.06
Trial(cationized fabric)

Control

The fastness properties are tested and graded as follows:

Parameter Test MethToeds t Results Test Results
Trial Cationized fabCroic Control Sample
Colour fastness ISO 105 B02 4-5 5
to Light
Colour fastness Is 764 4-5 4-5
to washing (60degree
Staining on Celsius)
adjacent 4-5 4-5
Polyester 4-5 4
Cotton 4-5 4-5
Wool 4-5 4-5
Nylon 4-5 4-5
Acrylic 4-5 4-5
Acetate
Rubbing IS 766
Fastness 4 4
Dry 4-5 4
Wet
Example 9
Cationization treatment is carried out in jigger prior to dyeing using 1.7 gram/per litre NaOH and 5 gram per litre RCP (50% active). It is observed that cationization works well even at very low level of cationization in no – salt, less – alkali reactive dyeing system. Dyeing in jigger using 2% shade of Reactive Yellow EDR dyestaff.
Control: 60 gpl salt and 20 gpl soda ash, 80 degree C, 60 min.
Dyeing of cationized fabric: No-salt and 15 gpl Soda Ash, 80 degree C, 60 min.
Results of dyeing performance:

Substrate Color strength Rubbing Fastn ess Wash Fastne ss
Dry Wet Rating Staining
Control 100 4-5 4-5 4-5 4
Cationized 98 4-5 4 4-5 4

Varieties of HE (high exhaustion) reactive dyes are tried with consistently good results. For a given shade, less amount of dyestuff is required to match the shade. This is due to more efficient and effective dye utilization which in turn is due to ionic attraction between the cationic cellulosic substrate and the anionic dyestuff. Dyestuff saving is an economical and environmental advantage.
ADVANTAGES
The most important advantage of the present is that it provides an environmental friendly process for dyeing fiber/yarn/fabric.
The other advantage of the present invention is to provide cationizing agent studded with large number of cationic sites and only a few welding groups.
Another advantage of the present invention is to provide cationizing agent endowed with water solubility and a favourable stereo-chemical conformation/configuration for intense dye-fibre affinity.
Another advantage of the present invention is to render more effective use of anionic dyes, yielding deeper shade-depths at a given concentration of dye in the dye-bath or achieving the required shed using lesser quantity of dyes.
Yet another advantage of the present invention is to avoid /reduce the amount of salt and alkali for nearly complete dye-exhaustion and dye-fixation.
Yet another advantage of the present invention is to help solve environmental problems by reducing pollutant load [dye hydrolysate, salt and alkali] in the drained dye-bath and in wash-waters generated in post-dye wash-offs, reducing thereby effluent treatment problems and cost.
Still another advantage of the present invention is better utilization of anionic dyes and particularly reactive dyes, thus leading to great economical and environmental help which would leave less unutilized and hydrolyzed dyes in wash-waters.
Still another advantage of the present invention is that the residual dye liquor having TDS 4.5 times lesser, COD 3.3 times lesser and BOD 4.2 times lesser as compare to the control.

Still another advantage of the present invention is that the first post dyes wash off having COD 8.6 times lesser and BOD 11.0 times lesser as compare to the control.
Still another advantage of the present is that it provides an environmental friendly process for dyeing fiber/yarn/fabric.

WE CLAIM
1. An environmental friendly process for dyeing fiber/yarn/fabric comprising the steps
of;
(a) treating fibers with a modified cationizing agent to induce more reactive sites on
the fiber surface;
wherein the modified cationizing agent is characterized as a reactive cationizing polymer (RCP) of amines and epichlorohydrine in the presence of crosslinking agent having viscosity in the range 200 to 1000 cps, the active polymer content in the range of 45-50% and pH in the range of 3 to 4;
(b) dyeing the treated fibers of step (a) with anionic dyes such as reactive dye or direct dye or indigo dye or combination thereof without use of salt and 25-100% less alkali in the dyeing process;
(c) washing of dyed fibers of step (b) to obtain desired dyed fiber/yarn/fabric.

2. The process as claimed in claim 1, wherein the amines are selected from the group comprising of methyl amine, dimethyl amine, trimethyl amine, ethylene diamine, diethylene triamine, hexamethylene triamine or combination thereof.
3. The process as claimed in claim 1, wherein crosslinking agents are selected from the group comprising of alkyl diamines and alkyl triamines such as ethylene diamine, diethylene triamine, hexamethylenediamine, bis(hexamethylene) triamine.
4. The process as claimed in claim 1, wherein the modified cationizing agent is prepared by the process comprising the steps of;

(a) reacting 1.5 – 2.5 mole dimethyl amine, 0.5 - 2.0 mole ethylene diamine, 1.7- 2.3 mole epichlorohydrine, wherein epichlorohydrine is added gradually with stirring and maintaining the reaction temperature below 25 °C;
(b) adding 0.4 – 1.0 mole diethylene triamine or bis(hexamethylene) triamine and 0.2 – 0.5 mole epichlorohydrine portion wise in step (a), wherein temperature increased to 60 °C and reaction continued for 3 hours, thereafter reaction temperature further increased to 90°C under stirring for 30 minutes;

(c) adding 3-4% soda ash of the total reaction mass and adding 0.4 – 0.8 mole epichlorohydrin which further increases the temperature of the reaction mass by 5 °C and allowed the reaction to continue to achieve the viscosity in the range 200 – 1000 cps;
(d) acidifying the reaction mass by adding in step (c) sufficient quantity of hydrochloric acid to obtain pH in the range 4-6 to obtain cationizing agent for treatment / cationization of fiber/yarn/fabric.
5. The process as claimed in claim 1, wherein the fiber/yarn/fabric are treated by 5 to 300 gm/kg of fiber/yarn/fabric of cationizing agent and preferably by 5 to 50 gm/kg of fiber/yarn/fabric of caionizing agent.
6. The process as claimed in claim 1, wherein the fibers are cellulosic fibers, wool, silk or their blends or combination thereof.
7. The process as claimed in claim 1, wherein the residual dye liquor having TDS 3 -5 times lesser, COD 2.5 – 3.5 times lesser and BOD 3-5 times lesser as compare to the control
8. The process as claimed in claim 1,wherein the first post dye wash off having COD 5 -10 times lesser and BOD 7-12 times lesser as compare to the control.