Eco-friendly Modified Silicone Poly-Acrylate Binder Synthesis and Application of Textiles Pigment Printing

Modified silicone environmentalfriendly poly-acrylate binder was prepared by emulsion polymerization technique using soft, hard, functional monomers. Newly synthesized binder was applied on fabric by pigment printing techniques. It was carried out on lab scale by simple screen printing techniques. We have synthesized this binder by using organic silicone, initiator, emulsifier, P H adjustor, deionized water and ammonia water as required. Binder should be soft, good film, high strength, good elasticity, excellent wash ability, strong adhesion, light color, excellent transparency and excellent light fastness, low cost and easy to implement production. Also get positive test results such as rubbing (wet & dry) fastness, water resistance of the film, softness, significant flexibility and staining resistance.


Introduction
Cotton is one of the most important fibers in the textile industry and its coloration could be achieved with either dyes, by dyeing or printing in aqueous solution or with pigment by using a print paste. Printing of cellulosic fibers are considered to account for more than 70% of all printed substrates and pigment printing is a major method [1]. The use of pigments for printing of textile products has dramatically increased over the last 50 years. Pigments are used to produce printed products for a number of end uses including apparels, home furnishing, crafts and nonwoven articles of the over 18 billion liners yards of printed fabric produced worldwide each years, about 50% of this yardage is pigment printed. In the united states alone, currently about 80% of all printing is done with pigment [2]. There are of course limitations to balance against the substantial advantages of pigment printing. The printer should be fully aware of these, since the use of pigments in applications where dyes are required can bring about a negative attitude to pigments, even in suitable applications [3]. In pigment printing, insoluble pigments, which have no affinity for fibers, are fixed on to the fibers with binding agents or binders [4]. Depending upon the properties required in the binding film (softness, elasticity, plasticity, solvent stability), binders can be tailor-made by choosing suitable base product. It is necessary to copolymerize different monomers. Typically, unsaturated monomers are used, such as vinyl chloride, dichloroethene, acrylonitrile, acrylic acid, esters and others. The binder used in the pigment printing process is usually based on styrene-butadiene, styrene acrylate or vinyl acetate acrylate copolymer [5]. Pigment printing technology of textiles has been applied widely because of its simple operation techniques, complete color and excellent fastness [6]. Generally, poly-acrylate, polybutadiene, polyvinyl acetate and polyurethane all can be used as pigment printing binder. Of course, poly-acrylate dispersion is the most prevalent one, nevertheless contained formaldehyde, highly hardness, inferior heat and cold resistance result pollution and worse application properties [7,8]. Very small amounts are required to achieve the desired properties, which offer cost effective textile operations and ensure negligible environmental impact [9,10]. Both outstanding properties of the binder as well as silicon addition to the pigment printing fabric contribute to crock fastness, good mechanical properties and resisting deformation of the coating on rubbing [11]. Organic silicone based textile binder, make not only fabric soft and smooth but also good elastic properties & increase the added value of the fabric [12]. The amount of silicon is explores during the preparation of binder by significantly. Observing resultant impact on polymer quality like solid content, gel ratio, polymer conversion rates, acid and alkali stability, electrolyte resistance stability etc. as well as resultant impact on printed fabric quality like dry & wet rub fastness, sublimation test [13,14] (Table 1) Properties of the monomer on the film: We select acrylic acid and hydroxyl-ethyl acrylate as a functional monomer due to its higher water solubility. [15]

Objectives
The aim of our task is to synthesize a good quality of binder which can be used for pigment printing process. The binder should be stable and not be degraded in the fabric during storage and use.

Binder Properties
The binder should be stable and not be degraded in the fabric during storage and use. Binder must have the soft handle properties. Binder should have good elastic recovery under strain. The adhesion strength of the binder to fiber bond has to be considered. A suitable binder should have also some other properties like strength, firmness, durability, stiffness, hydrophobicity, anti-microbial properties, organic compatibility, reduced surface tension, improved dimensional stability, wash and acid resistance.

Advantage of Poly -Acrylate Binder
Binder is monomers which on heating get converted into polymers. Binder actually holds the pigment color on fabric surface. Binder creates plastic coating and this coating help color to stick conditions.

Monomer
A molecule of any of a class of compounds, mostly organic, that can react with other molecules of the same or Textiles Pigment Printing other compound to form very large molecules, or polymers. The essential feature of a monomer is poly-functionality, the capacity to form chemical bonds to at least two other monomer molecules. Bi-functional monomers can form only linear, chainlike polymers, but monomers of higher functionality yield cross-linked, network polymeric products.
"So monomer is a simple compound whose molecules can join together to form polymers."

Monomer and Types of Monomers
The monomer can be categorized into three classes.
Soft monomers: Soft monomers, characterized by lower Tg values. These monomers are longer chain alkyl acrylates and exhibit low water solubility (i.e., high hydrophobicity Properties: We select styrene and acrylonitrile as a hard monomer providing structural strength, wear resistance, washing resistance so that the transparency of the cured film good, high fastness.
Functional Monomers: The third class is the functional monomer with various functional groups, such as carboxyl or hydroxyl which are very water-soluble.
Examples: Acrylic acid and Hydroxy-ethyl Acrylate.

Instruments & Reagents
Instrument using for binder: Electric blender, Round bottom flask, Electric heating system using by water bath, Initiator control by dropper, P H control by P H paper and also using color measurement instrument(SF 600), Crock master (Y571N) Instrument & Reagents for Pigment Printing: Using rotary screen printing method, Pigment, Poly-acrylate binder, Thickener, Distilled water as required.

Synthesis of Modified Silicone Poly-Acrylate Binder
Step I → 20% of total water, then add emulsify the monomer with surfactants at room temperature with continuous stirring.
Step II → Take AEO-9 and K-12 about 15 minutes at room temperature with continuous stirring.
Step III → Then run and put the monomer BA stirring at 10 minutes; After 10 minutes we need add ST EA and MMA; Then added NMA with stirring 40 minutes.
Step IV → Take out 5/6 parts pre-emulsion in a bottle; add remaining 80% of total water and then raises the temp. With continuous stirring. At temp 75-80°C, add 1/3 parts of initiators in the 1/6 pre-emulsion solutions and run about 20 minutes. Continue the process till for observing the blue beam in mixtures solutions.
Step V → When blue beam observed then remaining 5/6 parts of pre-emulsion and 2/3 parts of initiators put into the reactor simultaneously one by one in 90 minutes of time intervals at 78-82°C temp and stirring 30 minutes.
Step VI → Added the rest of 1/6 APS and increase the temp from 80°C to 85°C and keep it about 60 minutes. Until the sweet smell appears. (Note: If sweet smell not found or strong smell observed then add 10% extra initiators to the mixtures. Need to run another 20 min. at 85°C).
Step VII → When sweet smell is observed, cooling down at 40°C.Nuetralize the solutions by adding ammonia water (20%) to the solutions mixtures until PH=7-8 is not achieved.
Step VIII→ Collect all the segments and residue by filtration. Wash the entire residue and dry it at 105°C for 90 minutes.

Solid Content
The following are the testing methods to access the character of the synthesized binder.

Gel Ratio
After completion of the reaction, filter the emulsion collecting all gels, rinse, and baked in an oven at 120°C for 2 hours, cooled to room temperature in a desiccator, weighed and the gel fraction is calculated according to formula: Where, M → Dry weight of total Residue = {(0.30 / 100) ×100} % G →Total weight of monomer = 0.30%

Monomer Conversion Ratio (Table 3)
Draw l to 2 g emulsion to clean the weighing bottle, add 1 to 2 drops of a solution of hydroquinone, and baked in an oven at 120°C for 2 hours, cooled to room temperature in a desiccator. Weighing, the monomer conversion rate was calculated according to formula:

Particle Size Analyzer
Particle size dispersions measured by laser particle size analyzer. The minimum particle size in the emulsion was around 40 nm and the maximum particle size was 280 nm & the finally distributed average particle size was 120 nm.

Application of Modified Silicone Poly-Acrylate Binder on 100% Cotton Woven Bleached Fabric
The pigment printing pastes were prepared according to the following recipe:

Printing Method
The printed fabric dried at 120°C for 3 min and cured at 150°C for 2 minutes.

Evaluation of Color Fastness
For evaluation of 100% cotton printed fabrics, the following tests were performed: Fastness to rubbing, according to ISO 105-X12 Sublimation test, Durability test, Staining resistance, Yellowing and Softness test.

Optimization of Testing Methods
Assessment of the Sublimation test, Durability test, Rubbing (wet & dry) fastness test, staining resistance, Yellowing and Softness test of a printed fabric and results in (Table 4): After testing result we observed pass signal for sublimation and durability test. Then comparatively dry rubbing fastness value is high and yellowing and softness is comparatively satisfied.

Conclusion
Synthesis and application of eco-friendly modified silicone based poly-acrylate binder was performed in laboratory scale. From the synthesis of this binder we have got lower cost and from the application of this binder we have got moderate hand feel (Tg value is 16.48°C) with good rubbing fastness properties on printed fabric. We have tested our samples according to ISO test standard. The suitable conditions of reaction, maintaining time, temperature and dosage of chemicals help us to get a product with excellent properties.