Synthesis and application of cationic fluorinated acrylic resin for use in cathodic electrodeposition coatings

Abstract

Purpose

The purpose of this paper was to prepare a fluorinated acrylate resin, which would be synthesised via solution polymerisation of fluorinated monomer, acrylate monomers and other functional monomers. Relevant characterisation and application studies were also carried out. Fluorinated polymers are expected to be adopted in specific coatings to afford outstanding advantages, such as high chemical and photochemical resistance, low surface tension and low refractive index. At present, fluorinated cathodic electrodeposition (CED) coatings are attracting the attention that they deserve and seldom reported.

Design/methodology/approach

Cationic fluorinated acrylic resin was successfully prepared by solution polymerisation of dodecafluoroheptyl methacrylate, butyl acrylate, methyl methacrylate, dimethylaminoethyl methacrylate and methacrylic acid initiated by 2,2,-azo-bis-iso-butyronitrile in a solvent of butyl cellosolve. The resultant resin was neutralised with acetic acid. The CED coatings are prepared when moderate amounts of blocked isocyanate and distilled water were added into the resultant resin.

Findings

The hydrophobicity of the film is improved when the fluorinated monomer is introduced to co-polymerise with other monomers. The optimum conditions of preparing the resin are as follows: the amount of azodiisobutyronitrile is controlled with the range of 3.0 and 4.0 per cent; the amine value of the resin is 70 mg KOH/g; the hydroxyl value of resin and mole ratio of hydroxyl to isocyanate is 60 mg KOH/g and 1.0/1.0, respectively; the degree of neutralisation of the resin is within the range of 35 and 40 per cent.

Practical implications

The cationic fluorinated acrylic resin can be used to be the binder of CED coatings, which can be applied to electrodeposition finishing for high demand of exterior decorative and weather resistance, such as hardware, accessories, office furniture and so on.

Originality/value

The cationic fluorinated acrylic resin was successfully prepared by solution polymerisation. The hydrophobicity of the film is improved.

Citation

Chen, L., Li, W. and Jiang, W. (2014), "Synthesis and application of cationic fluorinated acrylic resin for use in cathodic electrodeposition coatings", Pigment & Resin Technology, Vol. 43 No. 5, pp. 251-255. https://doi.org/10.1108/PRT-10-2013-0093