Study on Corrosion Preventive Treatment of Steel Pipes by UV Curable Coating (III):Effect of Acrylate Diluents and Additives on Properties of UV Curable Primers for Polyethylene Coating of Steel Pipes
スポンサーリンク
概要
- 論文の詳細を見る
In order to optimize the formulation of ultraviolet rays curable primer (UV primer) for polyethylene (PE) coating of steel pipe, the relation between formulation and properties of UV primers of which base oligomer is epoxy di-acrylate has been investigated. And then it has been found what kind of acrylate diluents and additives has been suitable.<BR>Acrylate diluents with hydroxy group have given the UV primer low alkaline resistance as well as high adhesion to the adhesive with maleic anhydride branch. This phenomenon is due to that the hydroxy groups in acrylate diluent gives the UV primer high water absorption as well as high hydrogen bonding to carboxylic groups in maleic modified adhesive. The low alkaline resistance of UV primer induces the low cathodic disbonding resistance of PE coating. So, the acrylate diluents without hydroxy group has had to be used for the UV primer. And the glass transition temperature (<I>T<SUB>g</SUB></I>) of homopolymer prepared with the acrylate diluent has affected the <I>T<SUB>g</SUB></I> of the UV primer, so, the acrylate diluents with high <I>T<SUB>g</SUB></I> have been suitable to keep the adhesion strength high at high temperature.<BR>The alkaline resistance, mentioned above, has been also affected by the acid value of the UV primer and the acid value has been due to the residual acrylic acid in epoxy di-acrylate oligomer. Our research has made it clear that the addition of epoxy compound has been effective to reduce the acid value and the 2-4 wt% addition of bis-phenol A type epoxy of which numerical mean molecular weight is 380 has been the most suitable for the additive.
- Japan Society of Colour Materialの論文