Development of a new type of adhesive with high ad

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Development of a new adhesive for film lamination with high additive content (I)

I. problems raised

the advantages of composite flexible packaging have been found more and more, and its application scope has also been expanded. In addition to food, it has been widely used in drugs, cosmetics, daily necessities, chemicals, weapons, coatings, precision instruments, meters and complete sets of equipment. At the same time, with the different contents of the packaging, its requirements for packaging materials are also more and more diverse, such as requiring the materials to have breathability, softness, stiffness, lubricity, flame retardancy, antistatic, impact resistance, conductivity, insulation, anti-bacterial, anti-aging, anti radiation, easy degradation and so on, that is, the materials are required to have functionality. The solution is to add various functional additives in the film manufacturing process to obtain functional films, and composite various functional films to obtain multifunctional packaging materials

but this brings new composite problems. For example, in the manufacturing of the most common washing powder packaging bag, because the washing powder is a relatively fine powder, it requires that the packaging materials, especially the inner materials, have low surface resistivity and good smoothness. The powder does not splash, stick to the bag wall, pollute the seal, and the package is easy to open, which is conducive to high-speed packaging. Generally, the dynamic and static friction coefficients of the inner bag are required to be less than 0.3, and the surface resistivity is less than 1013 Ω, while the friction coefficient of ordinary LDPE is 0.6 ~ 0.8, and the surface resistivity is greater than 1014 Ω. The usual method is to use functional particles containing lubricant (or opening agent) and antistatic agent to blow the film. Among these particles, the content of lubricant is 400 ~ 600ppm (mg/kg), and when it is high, it is 1000ppm or more; Antistatic agent 0.1% - 1%.. The smoothing agent is usually oleic acid amide or erucic acid amide, and the antistatic agent is generally fatty acid recovery: uneven polyol esters are installed before and after the force measuring part, and they are only made of relatively cheap monomers with high polymer PE ε- Caprolactone( ε- CL) obtained directly through ring opening polymerization is a kind of mechanical mixing, which is not well compatible. The molecular thermal movement makes it gradually migrate to the interface with low free energy, resulting in the phenomenon of "frosting". Higher temperature accelerates the thermal movement of molecules, thus accelerating the migration and frosting phenomenon. The surface energy of these auxiliary molecules gathered at the interface is very different from that of general adhesive molecules, and the force between the molecules with low sub height is very small, so as to form a weak interface layer like release paper, which greatly destroys the adhesive force between the adhesive and PE. In this way, the manufacturer will find that the off machine strength is very good when laminating the film. After a period of time or curing, the peel strength decreases instead. After peeling, the inner layer of PE (towards the rubber surface) turns white, and sometimes it can be wiped off by hand. In fact, this is the migration of slippery agents and other additives

similar examples include pet ink//LDPE. After compounding, it is found that the strength of the ink is OK, but the strength of the blank is very low. This is because the slippery agent, antistatic agent or low molecular weight pet in the PET film migrate to the interface to reduce the adhesion. Where there is ink, it has stronger compatibility with these migrations than the adhesive, so it plays the role of primer or anchorage

in short, in order to obtain functional films, we have added various additives in the film manufacturing process, but the migration of additives will occur in the composite to offset the impact of functionality and even side effects. So how to solve this contradiction

second, the solution of GAOMENG company reduces the stiffness of all transmission systems.

the above problems can be solved by reducing the amount of additives, but the function of materials will be lost

or through the improvement of functional films, such as looking for more efficient additives, or adding coupling agents and other additives to reduce the migration of additives, or the particles themselves are functional polymers, but this is bound to increase the film cost

adhering to the principle of "adapting to diversified needs and providing professional services" and "providing customers with a full set of flexible packaging composite solutions", Mengren launched the solution of GAOMENG company - yh2600/yh25 new high additive content film adhesive after painstaking research

III. introduction to yh2600/yh25

1 See table 1

2 for physical properties Diluent

the solvents that can be used for this adhesive are ethyl acetate, acetone, methyl ethyl ketone, etc. it is recommended to use ethyl acetate. When manufacturing composite films with high quality requirements, the water content of the solvent shall not exceed 300ppm

3. Please refer to the instruction manual

4 for the use method Disc life

also known as the opening time, refers to the operable time after the two-component glue liquid is mixed into the working liquid in proportion. The disc stability of the glue with an operating concentration of 35% is about 7-8 hours at 35 ℃ and 90% RH. Under the conditions of relatively high humidity in the higher operating concentration range, a small amount of adhesive should be prepared, and they should be used up as soon as possible

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