Coating knowledge: alkyd resin (3)

Key tips: Section 5 modified alkyd resin Alkyd resin has good brushing and wetting properties, but it is poor in strength, chemical resistance and weather resistance Its disadvantages can be improved by modification The modification effect of alkyd resin can be summarized in table 4.1 Table 4.1 modification effect of alkyd resin The advantages and disadvantages of modifiers are fast drying of rosin and rosin ester, easy brush coating, yellowing when the hardness and adhesion are increased too much, the weather resistance decreases, benzoic acid and p-tert-butylbenzoic acid adjust the function of alkyd resin, increase the hardness, fast drying, improve the color, luster and chemical resistance, solubility and flexibility reduce the hardness and flexibility of phenolic resin Paint knowledge how about Akzo Nobel Powder Coating Recommended introduction: powder coating is a kind of coating with different form from general coating, which is in powder form It is a new type of coating, because of its own advantages and more and more known by people Let's introduce Akzo Nobel Powder coating Akzo Nobel Powder coating is a cost-effective coating solution, which can be applied to different kinds of products After the treatment of static electricity and fire baking, a tough and durable coating surface will be formed, with the least impact on the environment Since the introduction of this technology, powder coating has been able to continue to maintain the Paint Home News: the fifth section modified alkyd resin alkyd resin has good brushing and wettability, but it is poor in strength, chemical resistance and weather resistance, its shortcomings can be improved by modification The modification effect of alkyd resin can be summarized in table 4.1 Table 4.1 advantages and disadvantages of alkyd resin modifier: fast drying of rosin and rosin ester, easy brush coating, yellow when hardness and adhesion are increased too much, weather resistance decreases, benzoic acid and p-tert-butylbenzoic acid adjust function of alkyd resin, increase hardness, fast drying, improve color, luster and chemical resistance, solubility and flexibility decrease of phenolic resin Increase hardness, water resistance, alkali resistance, solvent resistance and chemical resistance, turn yellow, poor stability, fast drying of ethylene monomer (styrene, methacrylic acid), improve luster and color, improve weather resistance (methacrylate), water resistance (styrene), poor solvent resistance, reduce weather resistance (styrene), improve moisture resistance and weather resistance of organosilicon Reduce solvent resistance, too much drying difficulty, polyisocyanate (aromatic, aliphatic) improve dry rate, water resistance, adhesion, wear resistance, chemical resistance, weather resistance (aliphatic) aromatic yellowing, pulverization, short service life of two components 1, rosin modified alkyd resin 2, phenolic modified alkyd resin At the later stage of the synthesis of alkyd resin, the dosage is about 5-20% of the total amount The - CH2OH on the phenolic resin can react with the double bond of alkyd resin 3、 There are two methods to introduce styrene modified alkyd resin: the second method is easy to control and the product performance is good 4、 Fig 4.7 effect of silicone modification degree on Weatherability of long oil alkyd resin the alkyd resin paint modified by silicone has a great improvement on Weatherability and outdoor durability, so it is used as top coat on protective primer In recent years, waterborne alkyd resin saves a lot of solvents and reduces environmental pollution The waterborne alkyd resin can be made into water dispersible and water soluble type 1 Water dispersive type: polyethylene glycol is introduced The introduction of polyethylene glycol will cause the film to stick 2 The methods of introducing carboxyl group into water-soluble system: (1) copolymerization with alkene monomers containing carboxyl group (e.g AA); (2) DMPA (3) problems in using trimellitic anhydride: ① poor storage For example, the pH drops, the solution becomes muddy, even the resin precipitates, and the paint film loses its luster ② Shrinkage of paint film Home of coatings is specialized in coatings, diatom mud, paint coating, coating technology, fire retardant coating news and coating, diatom mud, paint coating, coating technology, fire retardant coating decoration knowledge and decoration renderings,