How to distinguish between fluorescent whitening agent OB and fluorescent whitening agent OB-1?

September 5, 2020 Longchang Chemical

1. Optical brightener OB and Optical brightener OB-1 are completely different chemicals

2. Optical brightener OB and Optical brightener OB-1, these two look like brothers. When many people hear Optical brightener OB and Optical brightener OB-1 for the first time, they take it for granted that Optical brightener OB-1 is a complex of ob. With the product, the purity of ob is reduced by one to become Optical brightener OB-1. So, what is the difference between Optical brightener OB and Optical brightener OB-1, what kind of product should use Optical brightener OB, and what kind of product is more suitable for optical brightener OB-1.

Chemical Name: Optical brightener OB-1

Other Name: Fluorescent Brightener 393 ; 4,4′-Bis(2-benzoxazolyl)stilbene ; Fluorescent brightener OB-1

CAS No.: 1533-45-5

Molecular Formula: C28H18N2O2

Molecular weight: 414.45

Optical brightener OB-1 Structure:

Appearance: Yellow greenish powder

Assay: 99%

Chemical Name: Optical brightener OB

CAS: 7128-64-5

Molecular Formula: C26H26N2O2S

Molecular Weight: 430.56

Optical brightener OB Structure:

Appearance: Yellow greenish powder

Assay: 99%

The optical brightener OB-1 is suitable for the whitening of chemical fibers such as polyester fiber, nylon fiber, and polypropylene fiber. Brightening and brightening of polypropylene plastic, rigid PVC, ABS, EVA, polystyrene, polycarbonate, etc. It is added in the conventional polymerization of polyester and nylon.

In order to achieve uniform whitening of plastics with different properties, the fluorescent whitening agent must not only adapt to the processing conditions of the plastic, but also have sufficient molecular dispersion or complete solubility in the plastic. In plastic, the optical brightening effect cannot be displayed or greatly reduced. The selection of the right models of different materials will greatly improve the brightening effect of the fluorescent whitening agent.

3. The molecular formula of Optical brightener OB is C26H26N2O2S, and the molecular formula of Optical brightener OB-1 is C28H18N2O2. From the picture above, we can clearly see that the two are completely different chemicals.

What product uses Optical brightener OB, which product is more suitable for Optical brightener OB-1?

Although they are two different chemical substances, from the naming, you can also guess that there are many similarities between the two. For example, Optical brightener OB and Optical brightener OB-1 have a wide range of applications. Most plastic ob and Optical brightener OB-1 can be used in common, and the whitening and brightening effect is obvious. So, where is the difference?

1. Melting point: Optical brightener OB-1>Optical brightener OB

Because the melting point of Optical brightener OB is 200 degrees, and the melting point of Optical brightener OB-1 is as high as 360 degrees, this determines that Optical brightener OB cannot be used for high-temperature plastic products, such as air conditioner casings and some kitchen utensils. Therefore, if your product requires high temperature processing, optical brightener OB-1 is your first choice.

2. Dispersion and stability: Optical brightener OB>Optical brightener OB-1

Here, we must first explain that good dispersibility means that the product is easier to dissolve and evenly. For example, paint and ink have high requirements on the dispersibility of the fluorescent whitening agent; good stability means that the product is not easy to migrate and yellow in the later stage. For example, some inferior shoe soles were white and clean when they were first bought, but they turned yellow and discolored after a while, which shows that the stability of the fluorescent whitening agent is poor.

Of course, I am not saying that the dispersion and stability of optical brightener OB-1 is not good, but it is slightly worse than ob. Because of this difference, Lianda Fluorescence Technology generally does not recommend using the optical brightener OB-1 in ink coatings and soft plastics. Ob is relatively better in dispersibility and weather resistance, and it is not prone to yellowing. The situation of migration.

The price is the biggest difference between Optical brightener ob and Optical brightener OB-1

In fact, the biggest difference between Optical brightener OB and Optical brightener OB-1 is the price. I remember that 6 years ago, the price of Optical brightener OB was similar to that of Optical brightener OB-1. However, because of China’s nationwide environmental protection rectifications, the raw material supply of Optical brightener OB had problems, so that the price of Optical brightener OB skyrocketed. Optical brightener OB is more than twice as expensive as Optical brightener OB-1. According to the estimation of Longchang Chemical R&D department, it may increase. Because of the huge price difference, customers who can use the optical brightener Optical brightener OB-1 should try to choose Optical brightener OB-1. Those with special requirements, such as high-end ink coatings and soft plastics, are recommended to use Optical brightener OB.

Facing the soaring price of Optical brightener OB, the R&D department of Longchang Chemical has continued to innovate and developed special brighteners suitable for various products to replace Optical brightener OB, reducing costs for customers, such as ld- for color masterbatches. s01, ld-y01 for special oil-based ink coatings, etc. Customers who need this can contact us.

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This article was written by Longchang Chemical R&D Department. If you need to copy and reprint, please indicate the source.

The following are the fluorescent brightener series products sold by our company.

Optical Brightener OB-11533-45-5
Fluorescent Brightener OB7128-64-5
Fluorescent Brightener ER-II13001-38-2
Optical Brightener CBS-X27344-41-8
Optical Brightener FP-12740470-68-6

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