Low temperature curing transparent inner iron printing coating

Abstract

The invention discloses a low temperature curing transparent inner iron printing coating. The low temperature curing transparent inner iron printing coating contains raw material by weight part: 40-65 parts of saturated polyester, 5-10 parts of amino resin, 0.2-1 part of modified adhesion promoter, 0.5-1 part of wax powder, 0.1-0.3 part of catalyst and 18-25 parts of environment-friendly organic solvent, wherein the saturated polyester has Tu-4 cup viscosity of 60-80s, acid value of 2-4mgKOH / g, solid content of 55-60wt%, glass transition temperature of 40-50 DEG C, and average molecular weight between 4000Da and 6000Da. Compared with the prior art, by selecting the branched saturated polyester high in acid value and glass transition temperature, crosslinking the selected saturated polyester with partly methyl-etherified melamine formaldehyde resin and n-butyl-etherified melamine formaldehyde resin, which are good in hardness and high in reaction speed, and simultaneously using benzoguanamine resin and isocyanate for auxiliary crosslinking, the low temperature curing transparent inner iron printing coating has good adhesive force to base material, good yellowing resistance, good scratch resistance, strong resistance to corrosion, and good processing performance, and only needs to cure for 8-11min at low temperature of 125-135 DEG C, is environment friendly and safe, does contain materials such as bisphenol A and organic tin, and is a product which meets domestic and international innocuous and harmless test standards.

Description

technical field [0001] The invention relates to the technical field of coatings, in particular to a low-temperature-cured transparent inner-layer iron printing coating. Background technique [0002] With the rapid development of my country's packaging industry, the various needs of the tin printing and canning industry have also been continuously updated and upgraded, and people's requirements for product packaging have also increased accordingly. The exquisite, durable and easy-to-recycle tin can packaging is constantly being used in biscuit tins. , moon cake boxes, tea cans, milk powder cans, beverage cans, aerosol cans and other products, this development has driven the development of related industries - printing iron coatings. Iron printing coating is a high-temperature thermosetting coating, which is applied to the metal surface by printing or roller coating, and then heated and baked to crosslink and solidify to form a tough coating film. In the field of iron printing ...

AI Technical Summary

Problems solved by technology

[0003] However, at present, most of the internal coating formulations of iron printing use epoxy resin as the main material, and the main component is the phenolic compound of bisphenol A, which is harmful to the human body and has an impact on human organs, especially on children's intellectual development and women's reproduction. Influence, so it is restricted to use at home and abroad

At the same time, the drying form of the coating in the iron printing process is a baking type, which has good adhesion and excellent alkali resistance. However, the inner coating of iron printing is in a high-temperature curing mode. The biggest problem is that the curing speed is slow, usually at 180- Baking and curing at 220°C for about 30-35 minutes, and the drying time for a single sheet is even as long as 35-40 minutes. Due to the long drying time, continuous production cannot be realized. The heat source required is usually gas or coal, which consumes a lot of energy. Energy and cause air pollution, thermosetting iron printing coating: such as CN103122203A discloses an inner layer iron printing coating, the main material of the formula is epoxy and bisphenol A resin, and the baking temperature is as high as 200 °C; CN103965750A discloses a special chemical barrel Iron printing coating and preparation method thereof, its hardness and luster are better, but baking temperature is also higher; CN103122201B discloses a kind of inner layer iron printing coating for food packaging, amino resin and phenolic resin are main materials, and bisphenol Catalyst A, baking temperature reaches 200-400℃