EP Topic: Silicone (III) Silicone oil modified acrylic resin

Epoxy resin has been widely valued since its emergence in the 1940s and has been widely used in many fields such as plastics, coatings, machinery and national defense. In recent years, its application has been extended to structural adhesives, as well as semiconductor packaging, fiber-reinforced materials, laminates, copper foils, integrated circuits and other fields. Epoxy resin has excellent mechanical properties, electrical properties, bonding properties, heat resistance, solvent resistance, as well as easy processing molding, low cost and other advantages. However, due to its three-dimensional mesh structure, the lack of sliding between molecular chains, carbon-carbon bond, carbon-oxygen bond can be higher on the smaller surface, with some hydroxyl and so on to make its internal stress is larger, brittle, high temperature easily degradable, susceptible to water. Silicone has the advantages of good thermal stability, oxidation and weather resistance, good low temperature performance, low surface energy and high dieletic strength, but its manufacturing cost is high, mechanical properties, adhesion, wear resistance, solvent resistance is poor. Silicone modified epoxy resin is an effective way to reduce the stress in epoxy resin and increase the properties of epoxy resin toughness and high temperature resistance in recent years. At present, silicone modified epoxy resin, the method mainly has two types of mixing and co-clustering. Copolymerization is the use of active end-radicals on silicones, such as hydroxyl, amino, alkyl and epoxy resin, epoxy, hydroxyl reaction to produce segment polymer, so as to solve the problem of compatible, and in the curing structure to introduce a stable and flexible Si-O chain, improve the rupture toughness of epoxy resin; However, the introduction of silicone chain segment with epoxy-based reaction not only consumes epoxy-based cross-linking of curing network, but also reduces the rigidity of epoxy resin, so toughening is accompanied by a decrease in heat resistance (Tg).3. Synthesis and performance of epoxy silicone oil modified acrylic resin (i) Introduction Acrylic resin has excellent photophobic, color preservation, outdoor durability, chemical resistance and physical and hydraulic properties, at the same time, it also has light color, low toxicity and other characteristics, but its water resistance is poor, room temperature curing rate is slow. By co-polymer and modified with other monomers and resins, the performance of acrylic resins can be changed in all aspects, and coatings can be prepared in a variety of properties and applications.epoxy modified acrylic resin is the introduction of acrylic-based unsaturated double bonds at both ends of the epoxy molecular chain, and then copolymerated with other monomers, resulting in a variety of excellent properties of epoxy resins (strong adhesion, low molding shrinkage, Good chemical stability, electrical insulation, as well as good thermal stability, etc.) in acrylic resin to be fully developed, its dryness, plumpness, gloss, hardness and other comprehensive performance is better than the general acrylic resin, suitable for decorative requirements of particularly high occasions.silicone material has excellent heat, weather, antioxidant, radiation and other properties, and the surface can be low, with water repugnant, anti-fouling. Therefore, silicone and acrylic copolymer can be made acrylic-type large molecules as the main chain, side chain is alkyl or hydroxyl silane or polysilane silicone modified acrylic resin, with the resin as the main film-forming silicone coating acrylic coating and silicone The length of the coating, not only has the ultra-weather resistance, but also has excellent water resistance, salt spray resistance, temperature resistance, stain resistance and wash resistance performance, mainly used in the weather resistance performance has special requirements of the building exterior paint, construction machinery coatings and the operating environment of the terminal equipment, marine facilities and other surface corrosion and decoration.The above three materials have their own characteristics, if the three materials are organically combined, the comprehensive performance of the material is better, but the reported research is mostly silicone modified acrylic resin or epoxy modified acrylic resin, epoxy resin, silicone and acrylic resin three organic combination of materials are less research. This experiment with styrene, acrylic as the main body, the application of special epoxy and silicone oil modified, through free-based solution co-polymerization into a common Newtonian-type epoxy resin with ethanol as the main solvent of a silicone monoacrylate material.(ii) experimental part 1, raw materialsmethyl acrylates (MMA), acrylates (BA), styrene (St), acrylic acid (AA), acrylic hydroxyethylate (HEA), are industrial grade; Acetoxybutyl (AIBN), acrylamide-based silicone oil, excellent grade; Epoxy 828, industrial grade; Ethanol ≥ 95%.
2, epoxy-silicone modified acrylic resin preparationAdd ethanol and glycol butyl ether (mass ratio of 4:1) to a four-mouthed bottle equipped with a thermometer, agitator and condensation tube, the temperature rises to about 50 degrees C, adds epoxy 828 resin, stirs as it heats up, and then dissolves completely until the epoxy resin is completely dissolved, and continues to heat up to the reflow temperature (85 degrees C). The pre-arranged mixed monosome (see Table 1) and the trigger in 2 to 3h drip into a four-mouthed can, insulation 2h, divided into 2 refractive agents, and then insulation 2 to 3h after stopping the reaction, get epoxy-silicone modified acrylic resin.1 Experimental Formula
Monosomes and Triggers
Mass Score/%
Acrylates (BA)
5 to 10
Methyl Acrylates (MMA)

15 to 20
styrene (St)
15 to 20
acrylic hydroxybuteride (HEA) 10 to 15
acrylic (AA))
5 to 10
oxyoxygen 828
20 to 25
acrylamide-based silicon oil
1 to 5
acetone diazole (AIBN)
1 to 5
(iii) Results and discussion 1, epoxy-silicone modified acrylic resin technical indicatorsepoxy-silicone modified acrylic resin technical indicators as shown in Table 2.Table 2 Epoxy-Silicone Modified Acrylic Resin Technical IndicatorsProject
Technical Indicators
Appearance
Light Yellow Translucent Liquid
Viscosity/ (mPa)
1200-1500
Solid Mass Score/%

60±1
(KOH) (mg.g-1) 65
Tg/C
40
thermal storage stability (50 degrees C)/d
15