At present, the biggest problem for low-temperature curing coatings should be the selection of materials.

The choice of this material will be related to the temperature of low-temperature curing, and it will also be related to the surface effect of the final molding of the coating.

Zhang Xiaofan definitely hopes that when the paint is formed, the surface leveling is very good, and there will be no orange peel.

The requirements are high, which will bring a lot of trouble to the researchers, and there will be many kinds of experiments in the test of materials.

Otherwise, the effect will not be achieved, and at present, the materials must mainly come from abroad, and the purity of the products of many domestic manufacturers cannot meet Zhang Xiaofan's requirements at all.

The products of domestic manufacturers can not be let go, in case they encounter a product, the purity is relatively high.

The products that can fully meet Zhang Xiaofan's requirements must not be let go, after all, the price difference between domestic and foreign products is still very large.

In fact, there are many manufacturers whose product quality is not much different from that of foreign products, but it is a big level behind in terms of fame.

So the audience of their products is very small, and there are very few people who know about it, in fact, there are many products that are of very good quality, but they just can't be sold, and then there may be a situation where such a brand will slowly disappear.

Under the guidance of Zhang Xiaofan, the progress of the experiment was very gratifying.

Zhang Xiaofan's requirement is that the curing temperature should be at least less than 150 degrees, which is very high for raw materials.

Many years later, it may be possible to do it, and it can be cured at 120 degrees, because at that time, the development of raw materials has reached a very high point.

120 degree curable coating, basically many substrates can be sprayed, including wood, plastic and so on.

In fact, for raw materials, there are definitely two main ones at present, one is epoxy resin, and the other is epoxy curing agent.

These two materials determine the curing temperature of the entire coating.

For low-temperature curing coatings, there are two main points for the current Duju building materials.

The first is that the curing temperature must be lower than 150 degrees, and the second is that the surface effect must be very good.

Zhang Xiaofan has been saying that there is never the best raw material, only the most suitable raw material.

In fact, the experiment is very simple, under the condition that the other raw materials are not changed.

The pigment remains the same, the filler remains the same, and the additives remain the same.

What needs to change are the two most important raw materials, epoxy resin and epoxy curing agent.

These two are formed, coated film-forming substances.

The most important substance of any coating is the film-forming substance.

As long as the film-forming substance is there, then it is a coating, but it may not be so good-looking, but as long as there is a film-forming substance, this coating is attached to the surface of the substrate and plays a role in anti-corrosion.

Now that the direction has been determined, the biggest key point of this research team must be to experiment with raw materials from various manufacturers.

Due to the formula listed by Zhang Xiaofan, this epoxy curing agent has not been used in the solid powder coating industry.

Therefore, this epoxy curing agent can only be passed by the molecular formula, and then go to find the corresponding supplier.

However, this is not difficult for Liu Qi and them, I don't know how many times they have been scolded by Zhang Xiaofan before, so as long as there is a molecular formula, it is relatively easy for them to find this kind of product.

In the past, many domestic chemical manufacturers established files, in order to one day, Zhang Xiaofan had a whim, only told you the molecular formula, and then asked you to find a finished product with high purity.

By now, Liu Qi and the others have expanded their archives abroad, because Zhang Xiaofan's requirements are getting higher and higher.

After many molecular formulas are written, you look for these manufacturers who produce other products, and you will find that their purity is very low, because there are too many by-products to produce a certain product, so the purity of the finished product is often not enough.

If the purity of the raw material is not enough, when it is applied to solid powders, many times something very strange will appear.

For example, it was originally made for flat highlights, but due to the impurity of the raw materials, it may become orange or even sand.

The more demanding the coating, the higher the purity requirements.

Because you don't know whether a by-product of a certain raw material will have an impact on the whole coating.

The research team has experimented with many kinds of raw materials, and five days have passed.

Zhang Xiaofan waited a little anxiously, although he would go to the laboratory every day to have a look, but he still couldn't bear Du Dalian's phone calls one after another.

So Zhang Xiaofan had no choice but to run to the laboratory again.

Let's see how Liu Qi's experiment progressed, it was only a day since Zhang Xiaofan came to the laboratory last time.

According to Zhang Xiaofan's estimate, there should not be much progress.

Especially when he saw Zhang Xiaofan coming to the laboratory, he hurriedly got up to greet him.

"How's it going?

"In the morning, we did an experiment that met our requirements, and I just asked everyone to re-do the experiment that met the requirements in the morning, and everyone is doing it once. ”

There was a surprise, it seemed that Du Dalian's call just now was relatively timely, and Liu Qi's caution also made Zhang Xiaofan feel very happy.

"What are the epoxy curing agents you're looking for?"

"Mr. Zhang, we have probably looked for seventeen or eighteen at home and abroad, and the highest purity is only 85%, due to the urgency of time, so there are still many manufacturers' products, and there are no experiments.

Many manufacturers' samples are still on the way, which is also a helpless thing, I just looked for some chemical companies that have stations in Yuezhou, but fortunately there is one, judging from the current situation.

It should meet the requirements, and the curing temperature we set is 145 degrees.

Just now, an experimenter made an experiment, and the surface of the sample was relatively flat, with positive and negative impacts, reaching 50 kg of Nm.

So in the afternoon, I asked everyone to stop what they were doing, and everyone experimented with this raw material once, and the results should be available later. ”

Zhang Xiaofan nodded, low-temperature curing paint, although the curing temperature is a little lower than the usual paint, but the time he needs will be a little longer.

Although it is a low-temperature curing coating, the reaction time is much longer when the reactivity is smaller.

This is a very normal situation, some coatings that can cure at 180 degrees have a curing time of about 10 minutes to 15 minutes.

At present, this kind of coating that can be cured with 145, Zhang Xiaofan guesses that its curing time should be 20 minutes to 25 minutes.

If a lower curing temperature is developed in the future, such as a 120-degree curing coating, it will take much longer.

Half an hour later, Zhang Xiaofan got the result.