Study on Performance of High Performance Waterborne Printing Coatings
The core and shell pre-emulsifiers were prepared from methyl acrylate (MA), ethyl acrylate (EA), butyl acrylate (BA), epoxy resin and emulsifier respectively, and then core-shell structures were prepared by seed emulsion polymerization. Polymer emulsions. Emulsion E.44 and organosilicone KH.570 were used to modify the polymerization emulsion to prepare an emulsion for printing. The effects of the ratio of emulsifier and core-shell monomer and the amount of different modifiers on the stability and film-forming properties of the emulsion were investigated. The results showed that the preferred conditions for the preparation of the emulsion were as follows: the mass fraction of the composite emulsifier [calcium (sodium dodecyl sulfate): m (non-ionic emulsifier OS.15) = l:3] was 4% The body composition is (MA):m(EA):m(BA)=I:l:3, the mass fraction is 30%~40%, and the shell monomer composition is m(MA):m(EA):m( BA)=2:l:l, the amounts of modified epoxy resin E.44 and organosiloxane KH.570 were 2% and 6%, respectively. When the baking process conditions are 140oC/3min, the obtained printing coating film has reached the design requirements in terms of elasticity, feel, fastness and other performance indicators.
In the paint printing process of the fabric, since the pigment itself does not have adhesive force to the fabric, it is necessary to apply the paint to fix the pigment on the surface of the fiber. Due to its excellent resistance to oxidation, weathering and outstanding oil resistance, polyacrylate-based emulsion polymers have strong adhesion to both polar and non-polar surfaces and have been widely used as printing coatings IIJ.
However, its disadvantages are that it tends to be sticky at high temperatures, it is brittle at low temperatures, and it has poor air permeability, water resistance, and stain resistance that are not ideal. The water resistance of the epoxy resin and the heat resistance and air permeability of the silicone are well complemented with the properties of the acrylic polymer. In this paper, polyacrylic emulsions were modified with organosiloxanes and epoxy resins, and an adhesive functional emulsion that can be universally applied to various fabrics was developed. After the emulsion is made into a printing coating, the hand feel is soft, the dry and wet rubbing fastness meets the requirements, and the soaping resistance is excellent.
2.I main raw materials
Methyl acrylate (MA), ethyl acrylate (EA), and butyl acrylate (BA) are all of analytical grade. Tianjin Kemiou Chemical Reagent Co., Ltd.: Epoxy resins E.44 and E.20, analytically pure, Yueyang Baling Huaxing Petrochemical Co., Ltd.; glycidyl methacrylate (GMA), KH.570, analytical grade, Guangzhou Double Bond Chemical Co., Ltd.; sodium dodecyl sulfate (SDS), potassium persulfate, analytical grade, Chengdu Joint Chemical Reagent Research Institute; OS.15. Analytical Pure, Guangzhou Hengyu Trading Co., Ltd.: rutile titanium dioxide, Nanjing Titanium White Chemical Co., Ltd.; urea, dimethyl silicone oil, Guangzhou Chemical Reagent Factory; WT.105 thickener, Deqian (Shanghai) Chemical Co., Ltd. Company; Emulsifier, distilled water, homemade.
2.2 Polymerization process
Separately quantify methyl acrylate, ethyl acrylate, butyl acrylate, epoxy resin, and emulsifier (4% of the total amount) and mix with water. Stir with a stirrer for 30 min to prepare a nuclear pre-emulsifier and shell pre-emulsification. Agent.
A four-necked flask equipped with a stirrer, a reflux condenser, a thermometer, and a constant pressure separating funnel was placed in a constant-temperature water bath, and a nuclear pre-emulsifier was added. When the temperature in the reactor rose to 80°C, the initiator was added dropwise. The process used 50% of the total initiating dose) while stirring was started (150 r/min) and the addition time was 90 min. The shell pre-emulsifier and the remaining initiator were then added dropwise over a period of about 30 minutes.
2.3 printing formula and process
Printing coating formulation: adhesive 56%, rutile titanium dioxide 40%,
Thickener 2%, dimethyl silicone oil 1%, urea l%.
Printing baking 140oC/3min finished product.
2.4 Emulsion and Product Performance Testing
Pull the cloth in the opposite direction with a pulling force of 30N to check the elasticity.
Touch the hand to check the softness.
2.4.3 gel rate