Pesticide soft compound bagged features and adhesive process

Pesticides are powerful weapons for harvesting crops to ensure good harvest. They include insect repellents, insecticides and herbicides.

In the past, most pesticides were packaged in glass bottles; glass bottles had the advantages of low permeability, good sealing, strong corrosion resistance, and long-term storage stability. But there are also three fatal shortcomings: First, the glass bottle is easily broken, the bottle breaks when it hits and falls, and the packaged pesticide spills. Because most of the pesticides are toxic, some of them are severely toxic to humans and animals. If pesticides are spilled due to broken land, they will pollute the environment and poison air, soil and water, which may cause serious harm to humans, livestock, fish and shrimps. And economic losses. The second is a glass bottle with a small volumetric volume ratio, a 1200 ml bottle, a 1000 ml bottle of pesticide, and a 6mmm empty bottle of a truck that can hold up to 5 tons of pesticide. Third, the glass bottle has a smaller capacity-to-weight ratio. A glass bottle weighing about 500 grams can only be loaded with 1,000 grams of pesticide. A tank of 5 tons of empty bottles can be pulled, and only 10 tons of pesticides can be loaded. The latter two drawbacks at the same time caused an increase in storage and transportation costs.

Because pesticides are indispensable in the national economy, their storage, transportation, sales, and use cannot be without packaging. After seeing the shortcomings of glass bottles, people must find ways to find other packaging materials to replace it. The first approach is to use a high-quality plastic bottle, which overcomes the problems of fragility and small capacity-to-weight ratio, but cannot overcome the problem of small volume-to-volume ratio. A plastic bottle with a shape volume of 1200 ml can only hold 1,000 ml of pesticide. And its sealability is inferior to glass bottles. Followed by light metal bottles made of aluminum, but its proportion is at least twice as much as plastic, in addition to the small volume and volume ratio, but also the problem of small capacity and weight ratio, and the metal prices are high, the packaging cost is too high. With the advent of soft composite packaging materials and its outstanding advantages, it has been adopted by pesticide packaging in recent years.

Soft composite packaging materials made into bags to package pesticides have the following advantages:

1, good sealing. As long as a suitable substrate is selected, airtightness, impermeability, impermeability, impervious to solvent, and light transmission can be achieved, and the effect on the shelf life of pesticides is good.

2. It is not easily broken or even tougher than a plastic bottle. When it is squeezed, bumped or dropped, it does not break. It can safely protect pesticides from outflow, effectively eliminating air, environment, soil and water quality. Pollution to ensure the safety of human, animal, fish and shrimp.

3, large volume ratio, is not comparable to any rigid bottle. A compound bag with a volume of only 4.2 ml can be filled with more than 150 ml of pesticides with a volumetric volume coefficient of 35 or more. That is, a 1 cubic centimeter composite bag can be used to package 35 millimillimeters of pesticides. The capacity volume factor of the bottle is only 0.80-0.83, that is to say,
The 1.2mmm bottle can only be filled with pesticides from Chuantun. From this comparison, the packaging efficiency of the soft composite bag is 45 times that of the bottle.

4, the capacity and weight ratio is also great. A soft composite bag weighing 5 grams can be filled with more than 150 grams of pesticides, with a capacity-weight coefficient of 30, and only 2 glass bottles, 8 plastic bottles, and only 5 lightest metal bottles. From the above points of view, the transport and storage costs of flexible composite bags are much smaller than those of bottles. Because of the unparalleled advantages of composite bags, it is widely used in packaging farmers with a great market prospect. However, because of the diversity of pesticides, it also has a strong corrosive effect. Therefore, adhesives for the production of flexible composite packaging bags require high requirements. In general, adhesives that can be used in the packaging of foods and medicines cannot be applied to pesticide packaging. This is a factor that restricts the use of soft composite packaging materials in a large number of pesticide packages. Although the future is vast, there are also great risks.

For this reason, in the past three or four years, we have conducted research and development on adhesives for pesticide packaging. Although we have encountered many difficulties, we have also made some progress. Let's introduce our LY-50VR/LY-50VRH pesticide packaging adhesive.

It is a solvent-based two-component polyurethane adhesive, called the main agent and curing agent, respectively. The main agent has a solids content of 50% and a viscosity of 300-600 mPa.s. The curing agent has a solids content of 70% and a viscosity of 800-1500 mPa.s.

Second, the adhesive synthesis

The adhesive is polyester polyurethane, which is characterized by the fact that in addition to the polar structure of carbamate (-NCO-day-) arranged in the molecular chain, it also contains epoxy groups (-CH- Active groups such as CH-CHH), carboxyl (-C-OH) and silane isocyano groups. The content of each active group is not completely the same, there are some more, some less, more than 200 milligrams of equivalent per 100 grams of resin, and less than 40 milligrams of equivalent per 100 grams of resin.

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