Study On The Synthesis And Performance Of Water-soluble Acrylic Alkyd Resin

The water-soluble coating is a new class of resource saving, energyefficient paint that is developed in the1960s, with water instead oforganic solvents, not only low-cost, convenient construction, lesspolluting the environment, but also fundamentally prevent the solventcoatings from fire hazards during the production and constructionprocess for solvent evaporation, reducing organic solvents hazards forpeople health. The alkyd resin is the most widely used synthetic resinwith excellent durability, gloss, gloss and color retention resistance,hardness and flexibility, and other synthetic resins (such as acrylic resin,silicone, epoxy, styrene, etc.) modified, can be made with a variety ofperformance coatings, occupies an important position in the paint.There exist a number of problems in the water-soluble paint itself,limiting its development and application. These problems are mainly asfollows: first, water evaporation latent heat increases the drying time ofthe paint film; second, large surface tension of water will produceproblems such as shrinkage; third, difficult applications in the water-sensitive substrate limits the scope of the workpiece coated; fourth, in aweakly alkaline aqueous solution, ester bond hydrolysis affects storageand use performance of the coating, reduces the film’s resistance towater-soluble, shorten the film life. Linseed oil is used as fatty acid inthis article to optimize complex combination of pentaerythritol andtrimethylol propane, explored effective methods synthetic water-solublealkyd resin, studied the influence factors generated by the water-solublealkyd resin and the resin structural characterization, overcomedtraditional alkyd resin shortcomings with poor storage stability and poorwetting force; acrylic resin has characteristics with light color,lightfastness, weathering, corrosion resistance, gloss and color retention,using acrylic to modify alkyd resin, three experimental programs have been used to synthesize acrylic modified alkyd resin, focusing on whatfactors affect the conversion rate, reaction temperature, acidity, viscosityof the acrylic acid ester copolymer in order to better synthesize modifiedresin; there compare how the viscosity of the resin, ratio, the selectionand amount of catalyst and curing agent affect resin paint traits, yield,the degree of curing, resistance to dry, water resistance, durability, andstability with changing the performance, so that alkyd resin has excellentadvantages with durability, weather resistance, corrosion resistance,gloss and color retention, quick-drying, high hardness, and expand theapplication fields of the alkyd resin. The main contents and results are asfollows:(1)Using linseed oil fatty acid synthesis as the water-soluble alkydresin, that fixed content is45%, viscosity is210MPa s, it improveswater resistance, oil resistance, storage stability of the resin; in theesterification reaction, the optimum condition of resin synthesisparameters is controlled in a temperature range of160-200℃, in an acidvalue of trimellitic anhydride between10-15mgKOH/g, and the endpoint controlled at40-60mgKOH/g; polyol combinestrimethylolpropane and pentaerythritol both with the ratio of4:1,neutralizer selecting triethylamine, cosolvent selecting ethylene glycolbutyl ether, which is suitable for synthetic water-soluble alkyd resin; inaccordance with national standards testing, the film of water-solublealkyd made with linseed oil comply with standards that are waterresistance, salt spray resistance, oil resistance, and without foaming,non-shedding, excellent resistance to dry,better storage stability.(2) Using Acrylic acid to modify a water-soluble alkyd resin,improving the conversion rate of acrylic acid ester copolymer, theconditions are to select acrylic acid, α-methyl acrylate, methylmethacrylate for copolyesters monomer, initiator content is1%, addingin the monomer mix drops twice, first initiator dropping is added4h,incubated for1h, supplemented with the remaining the initiatordropping2h, incubated for4h, the copolymerization reactiontemperature is78-80℃; comparing esterification and copolymerizationof modified alkyd resin, modified resin that is esterified has better solvent resistance, wettability, storage stability, comparing fatty acidmethod and monoglyceride of the esterification, prepared modified resinhave better resistance to dry, so fatty acid should be prepared formodified water-soluble acrylic alkyd resin; the best condition of theesterification process of the modified resin is that the reactiontemperature is controlled to220℃, fatty acids react for4h during usingthe esterification method, adding TMP for second esterification reactionuntil the end of the acid value20mgKOH/g; oil degree of basic alkydresin made with drying oils-linseed oil is control in50%, modified resin,that is synthesized by acrylic acid, possess better gloss and colorretention, durability and stability properties; the ideal modified resincannot be synthesized with rapeseed.(3) Using above resin as the synthetic raw material, which preparedaccording to the paint formulation basic, water-soluble alkyd resinmodified paint. There are many factors impacting the modified resinpaint, the experiment study the influence of viscosity before and afterthe resin-modified from resin solid content, solubilizers, diluents, toimprove the leveling of the resin varnish. The optimum conditions of thebasic resin is45%solids, viscosity is210mPa·s, diluent is water,cosolvent is ethylene glycol monobutyl ether added50%of the totalamount, catalyst is between0.4-0.6g，degree is between65-75%. Themodified paint selection and amount of cosolvent and diluent is the sameto basic paint, that the best experimental conditions is50%solids,viscosity is1090mPa·s, the acrylic copolymer used in an amount of20%, the yield reached90%, catalyst is2.5g, curing agent is0.6g，degree is between60-70%. With detailed comparison of the productperformance indicators before and after modification, modified resin hascharacteristics of the acrylic resins and alkyd resins, that water resistance≥168h than the unmodified≥120h, significantly enhanced resistance todry shortened from23h to9h, and its gloss and color retention,compatibility, wetting, acid and alkali, solvent have improvedsignificantly in film properties, greatly reducing the content of VOC.