
Product Name: Optical Brightener ER-III / Fluorescent Brightener 199:2
Chemical Name: 2,2′-(1,4-Phenylenedi-2,1-ethenediyl)bisbenzonitrile
Color Index: C.I. 199:2
CAS: 79026-03-2
Molecular Formula: C₂₄H₁₆N₂
Formula Weight: 332.40 g/mol
Synonyms: Fluorescent Brightener 199:2; FBA 199:2; Fluorescent Whitening Agent ER-III; 2,2′-Bis(2-cyanostyryl)benzene; Optical Brightening Agent ER-III;
2-[2-[4-[2-(3-Cyanophenyl)ethenyl]phenyl]ethenyl]benzonitrile
Application:
Polyester Fibers (Dacron), Acetate Fibers, Polyamide Fibers (Nylon), Polyester-Cotton Blends, Polyester-Wool Blends, Polyester-Linen Blends, Polyester-Silk Blends, PVC, Polystyrene, Synthetic Leather, Paints & Coatings
1.Product Description
Achieve Exceptional Whiteness with Optical Brightener ER-III – The Premium High-Temperature Brightener for Polyester and Blends.
Optical Brightener ER-III, internationally designated as Fluorescent Brightener 199:2 (C.I. 199:2), is a premium distyrylbenzene derivative engineered specifically for whitening polyester fibers and their blends at high processing temperatures . This sophisticated non-ionic brightener features a unique molecular structure with a 2-cyanostyryl configuration that delivers exceptional thermal stability and outstanding sublimation fastness .
What truly distinguishes ER-III from other brighteners in the ER series is its superior sublimation fastness. While ER-I and ER-II are designed for lower-temperature applications, ER-III maintains its whitening efficacy at elevated temperatures, making it the preferred choice for high-temperature fiber spinning, setting, and heat treatment processes . The compound absorbs invisible ultraviolet radiation and re-emits it as brilliant blue-violet visible light (bluish-violet fluorescence), effectively neutralizing the natural yellowish cast of polyester and synthetic fibers .
Key differentiators:
Superior Sublimation Fastness: Maintains whitening effect through high-temperature setting and heat treatment processes, ensuring durable whiteness in finished products .
High Thermal Stability: Withstands processing temperatures up to 280-300°C with excellent stability, suitable for demanding textile and plastic applications .
Excellent Lightfastness: Demonstrates outstanding resistance to UV exposure, maintaining whiteness through prolonged sunlight exposure.
High Purity Formulation: Available in ≥98% purity with consistent batch-to-batch performance .
Our Optical Brightener ER-III is manufactured under strict quality controls, offering consistent performance and compliance with international quality standards for textile applications.
2. Product Specifications (Technical Data Sheet)
| Property | Specification | Insight |
| Product Name | Optical Brightener ER-III (Fluorescent Brightener 199:2) | Premium high-temperature brightener for polyester |
| Appearance | Bright yellow to yellowish-green crystalline powder | Uniform, free-flowing powder |
| CAS No. | 79026-03-2 (primary); 13001-40-6 (related isomer) | Verified chemical registry number |
| EINECS/EC No. | 279-038-7 | Listed in European inventory |
| Molecular Formula | C₂₄H₁₆N₂ | Distyrylbenzene with 2-cyanostyryl groups |
| Formula Weight | 332.40 g/mol | |
| Solubility | Insoluble in water; soluble in most organic solvents (toluene, xylene, chlorobenzene, DMF) | Excellent organic solubility for polymer applications |
| Ionic Style | Non-ionic | Compatible with anionic and cationic systems |
| Fluorescence Color | Bluish-violet | Produces clean, bright white appearance |
| Melting Point | 276-283°C | Excellent thermal stability |
| Purity | ≥ 98% - 99% (HPLC) | High purity ensures consistent performance |
| Density | 1.187 g/cm³ | |
| Storage Conditions | Store in cool, dry, ventilated warehouse; avoid sunlight, moisture, and heat | Shelf life: 2-4 years under proper storage |
| Packing | 20-25 kg fiber drums / cardboard cartons with PE inner liner; 25 kg plastic drums for liquid formulations; custom sizes available | Secure, moisture-proof packaging |
| Application | Polyester fibers, acetate fibers, polyamide fibers, polyester-cotton blends, PVC, PS, synthetic leather, coatings | Versatile across multiple industries |
3.Product Application
Textile Industry – Primary Application:
Optical Brightener ER-III is the preferred whitening agent for polyester and synthetic fibers, particularly valued for its high sublimation fastness and excellent performance in high-temperature processes :
| Fiber Type | Application Method | Recommended Dosage | Processing Conditions |
| Polyester (PET) Fibers | High-temperature exhaust dyeing | 0.02-0.08% (o.w.f) | 120-130°C, 30-60 min, pH 4.5-5.5 |
| Polyester-Cotton Blends | Pad dyeing | 1.5-3.0 g/L | Two-dip two-pad → 100°C pre-drying → 180-190°C curing (40-30 sec) |
| Polyester-Wool Blends | Exhaust dyeing | 0.05-0.15% (o.w.f) | Suitable for blended protein/synthetic fibers |
| Polyester-Linen/Silk Blends | Exhaust dyeing | 0.05-0.15% (o.w.f) | Effective for natural/synthetic blends |
| Acetate Fibers | Exhaust dyeing | 0.05-0.1% (o.w.f) | Provides bright, clean whiteness |
| Polyamide (Nylon) Fibers | Exhaust dyeing | 0.05-0.1% (o.w.f) | Effective whitening for synthetic fibers |
Low-Temperature Absorption Process:
For applications requiring lower processing temperatures, a two-step process can be employed:
| Step | Conditions | Duration |
| Absorption | 50-60°C, pH 4.5-5.5, 0.3-0.7% (o.w.f) | 20-30 minutes |
| Fixing | 180-190°C (setting and baking) | 40-30 seconds |
Plastics & Synthetic Leather:
ER-III demonstrates outstanding whitening performance across various plastic applications:
PVC (Polyvinyl Chloride): Effective for both rigid and flexible PVC; dosage 0.01-0.05%.
Polystyrene (PS): Suitable for injection molding applications.
Synthetic Leather: Provides excellent whitening for artificial leather products .
Coatings & Paints:
ER-III is suitable for coating applications, providing excellent whitening effects in solvent-based systems for industrial and specialty coatings.
4.Storage
This product may be stored up to two years in a sealed container. Containers should be kept tightly closed when not in use and stored in a cool, dry place.
5.Packaging
Usually is 25Kg/drum or paper box or bag with inner double PE liner Or provide customized packaging according to customer requirements.
6.Our advantage
1) Provide free samples for testing or comparing the effect difference and cost performance.
2) Fast response speed, customers' questions at any time will be responded to in two hours.
3) Fast delivery: the fastest delivery can be made on the same day.
4)Different packaging solutions: provide various packaging options according to customer requirements.
5)Technical guidance: provide improved whitening and coloring formulas and guidance according to customer production materials.
6) Sample retention or sample mailing before bulk delivery.
7) Providing certificationes, such as Reach certification.
8) Different payment methods: TT LC, etc.
9) Providing door-to-door DDP service.