Method for preparing fluorine-containing silicon acrylate emulsion

Abstract

The invention belongs to the field of modification of acrylate and in particular relates to a method for preparing fluorine-containing silicon acrylate emulsion by an emulsion polymerization method. The method comprises the following steps of: 1) mixing octamethylcyclotetrasiloxane, trifluoropropylmethyl ring trisiloxane, vinyl siloxane, an acrylate monomer, a composite emulsifier, an initiator, a pH conditioning agent and distilled water to perform pre-emulsification to obtain pre-emulsified liquid; 2) stirring part of the pre-emulsified liquid under the atmosphere of inert gas, heating at the temperature T1, adding the residual pre-emulsified liquid into a reaction system dropwise, and heating at the temperature T2; and 3) cooling to room temperature under stirring, filtering by using a 200-mesh filter screen to obtain the fluorine-containing silicon acrylate emulsion. In the preparation method, the reaction process is mild and easy to control; and the product has excellent waterproof and oilproof properties.

Description

technical field [0001] The invention belongs to the field of acrylate modification, and in particular relates to a method for preparing fluorine-silicon monomer and acrylate block copolymer emulsion by emulsion polymerization. The fluorine-containing silicon and acrylate block copolymer emulsion can be used as leather and natural fiber fabrics , Waterproof and oil-proof finishing agent for chemical fiber fabrics and paper. Background technique [0002] Polyacrylate emulsions have excellent transparency, film-forming properties, weather resistance, mechanical stability and adhesion, and are rich in raw materials and low in cost. They are widely used in coatings, textiles, leather, papermaking, adhesives and other fields. However, its stain resistance and water resistance are not ideal, and its cold resistance and heat resistance are poor, and it is prone to the phenomenon of "hot sticking and cold brittleness", which limits its further application. Fluoropolymers have prope...

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Problems solved by technology

However, this technical solution has the following obvious deficiencies: one, ① perfluorohexyl ethyl acrylate, ② perfluorooctyl ethyl acrylate, ③ perfluorodecyl ethyl acrylate, ④ perfluorohexyl ethyl acrylate Methacrylate, ⑤ Perfluorooctylethyl methacrylate, ⑥ Perfluorodecylethyl methacrylate and other monomers are currently produced by very few domestic manufacturers, or they are difficult to produce and expensive

In addition, the biodegradation of long-chain fluorinated alkanes is difficult, and the sewage treatment is difficult

Second, the fabrics treated with quaternary ammonium salt cationic surfactants have unpleasant smell of quaternary ammonium salt cationic surfactant residues

3. The water-repellent performance (polyester) of the water-repellent and oil-repellent agent obtained by this technical scheme is only 80-90 points (up to 100 points) according to AATCC22, and the oil-repellent performance (nylon) is only 3-5 grades (up to 8 points) according to AATCC118. level), it should be said that the effect is not ideal

However, all the raw materials used in the reaction are organosilicon fluorine monomers, which are expensive, and the preparation needs to be carried out in acidic conditions with a pH of 2 to 4 and a pressure of 30 to 40 MPa for high-pressure homogeneous emulsification, and then to react. The preparation process is complicated, and the product is organic. Fluorosilicone resin molecules lack groups that react with the surface of the fiber, so there will be certain limitations in the application of the bonding fastness between the resin molecule and the fiber.

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