Development of aluminum foil protective coating fo

Development of aluminum foil protective coating for drug packaging (Part I)

Abstract: aluminum foil protective coating for drug packaging is made of thermosetting acrylic resin and nitrocellulose. The production process of resin, preparation and properties of paint are introduced, and various influencing factors are discussed

key words: drug packaging aluminum foil thermosetting acrylic resin nitrocellulose protective coating

aluminum foil blister packaging of drugs is the most widely used drug packaging method at present. It has the advantages of moisture-proof, safety and health, long shelf life, easy to carry and use, etc. at the same time, it also has the advantages of low cost, fast production speed, convenient transportation, etc. Aluminum foil for drug packaging is generally composed of five parts: protective layer, outer printing, aluminum foil substrate, inner printing and adhesive layer. The main functions of the protective layer are:

(1) modify the surface of aluminum foil, make the surface of aluminum foil bright and flat, and fill the small gaps on the surface of aluminum foil

(2) improve the acid-base corrosion resistance of aluminum foil and extend the shelf life of drugs

(3) it has a certain hardness and bonding strength, protects the printing ink on the outside, and adheres well to the aluminum foil substrate without falling off. When compounding at high temperature (150-180 ℃), the coating will not stick to the stick of the drug packaging machine due to softening and tackiness. In this test, thermosetting acrylic resin is used, and through the coordination with appropriate nitrocellulose, additives, solvents, etc., aluminum protective coating for drug packaging with good heat resistance, strong adhesion, plump coating, rapid drying, good uncoiling performance and excellent performance is obtained

1 test part

1.1 raw materials and instruments and equipment

1.1.1 main raw materials and specifications

methyl methacrylate, industrial grade; Butyl acrylate, industrial grade; Methacrylic acid, industrial grade; Acrylamide, industrial grade; Formaldehyde,

industrial grade; Initiator, reagent; Additives, industrial grade; Nitrocellulose,

industrial grade; Solvent, industrial grade

1.1.2 simultaneous test instruments and equipment

super constant temperature water bath; Electric heating sleeve; Electric Blender; X-1 rotary vane vacuum pump; Constant temperature drying box; Commonly used glassware

1.2 synthesis of thermosetting acrylic resin

1.2.1 formula

the formula of thermosetting acrylic resin is shown in Table 1

1.2.2 synthesis process

add solvent methanol into the four mouth bottle equipped with agitator, reflux condenser and thermometer. Start stirring and heat up. At the reflux temperature, the monomers and initiators of anti emotional intelligence children in the whole school were added in a certain order. After all dripping, the joint peeling performance of high molecular waterproof coiled material gb/t328.21 ⑵ 007, reaction for 2 hours. Then, toluene is added and methanol is evaporated out. After all the methanol is evaporated, the temperature is reduced to obtain thermosetting acrylic resin

1.2.3 technical indexes of thermosetting acrylic resin

technical indexes of thermosetting acrylic resin are shown in Table 2

1.3 preparation and performance of aluminum foil protective coating for drug packaging

1.3.1 paint making

add human thermosetting acrylic resin, nitrocellulose, additives and solvents according to the formula and stir them evenly, then

2 results and discussion

2.1 selection of raw materials

the important performance requirement of aluminum foil protective coating for drug packaging is that the protective layer formed on hard aluminum foil has strong adhesion to aluminum foil, In high temperature hot pressing composite (150-200 ℃:), it has higher hardness without sticking. Nitrocellulose has good tensile strength, high hardness and fast solvent release. When its content reaches a certain level, it can meet the hardness requirements. Thermosetting acrylic resin is used on metal surfaces as a protective or decorative coating. After curing, it has excellent properties in all aspects, such as light retention, color retention, corrosion resistance, heat resistance, adhesion and so on. After comprehensively considering the properties of the two resins, nitrocellulose and thermosetting acrylic resin are selected as the main film formers of aluminum foil protective coating for drug packaging to ensure that the protective layer has good hardness, adhesion, heat resistance and corrosion resistance when painting is required