
Product Name: Optical Brightener FP-127 / Fluorescent Brightener 378
Chemical Name: 4,4′-Bis[2-(2-methoxyphenyl)ethenyl]-1,1′-biphenyl
Color Index: C.I. 378
CAS: 40470-68-6
Molecular Formula: C₃₀H₂₆O₂
Formula Weight: 418.53 g/mol
Synonyms: Fluorescent Brightener 378; Fluorescent Whitening Agent FP;
4,4′-Bis(2-methoxystyryl)biphenyl; C.I. 378; Uvitex FP; CSFC 127;
4,4′-Bis[(E)-2-(2-methoxyphenyl)ethenyl]-1,1′-biphenyl
Application:
Plastics (PVC, PE, PP, PS, ABS), EVA, TPU, PU, TPR, Synthetic Leather, Paints & Coatings, Printing Inks, Man-Made Fibers, Rubber, Adhesives, Polymer Masterbatch
1. Product Description
Achieve Brilliant, Whiter-Than-White Plastics with Optical Brightener FP-127 – The Premium Fluorescent Whitening Agent for Modern Polymer Applications.
Optical Brightener FP-127, internationally designated as Fluorescent Brightener 378 (C.I. 378), is a high-performance bis(styryl)biphenyl-based optical brightening agent engineered specifically for the plastics, coatings, and synthetic materials industries . This sophisticated compound represents the next generation of whitening technology, offering exceptional thermal stability and outstanding whitening efficacy across a broad spectrum of polymer matrices.
The unique molecular architecture of FP-127—featuring a conjugated biphenyl core with methoxy-substituted styryl groups—enables superior UV absorption and fluorescence emission characteristics. The compound absorbs invisible ultraviolet radiation in the 359-374 nm range and re-emits it as brilliant blue-violet visible light at approximately 434 nm, effectively neutralizing the inherent yellowish cast common in many polymers and creating a visually striking, high-brightness white appearance .
What distinguishes Optical Brightener FP-127 from conventional whitening agents is its exceptional combination of high purity, thermal stability, and polymer compatibility. With a melting point of 216-222°C and ≥99% purity, FP-127 maintains its whitening efficacy throughout demanding melt processing operations including injection molding, extrusion, and calendaring . The compound is insoluble in water, odorless, and exhibits excellent stability during storage and processing .
Superior Performance for PVC and Polyolefin Applications: FP-127 demonstrates particularly outstanding results in PVC (polyvinyl chloride) and polyolefin (PE, PP) applications, delivering a brilliant fluorescent blue effect that masks yellowness and imparts a clean, bright appearance . Its effectiveness extends to synthetic leather products, where it provides exceptional whitening and brightening results that enhance product aesthetics and market appeal .
Our Optical Brightener FP-127 is manufactured under strict quality controls with consistent batch-to-batch performance, making it the preferred choice for high-value plastic products, engineering polymers, and specialty coating applications worldwide.
2. Product Specifications (Technical Data Sheet)
| Property | Specification | Insight |
| Product Name | Optical Brightener FP-127 (Fluorescent Brightener 378) | Premium bis(styryl)biphenyl brightener for plastics |
| Appearance | Light green to light yellow-green uniform crystalline powder | Fine, free-flowing powder with excellent dispersion characteristics |
| CAS No. | 40470-68-6 | Verified chemical registry number |
| EINECS/EC No. | 254-935-6 | Listed in European inventory |
| Molecular Formula | C₃₀H₂₆O₂ | Bis(styryl)biphenyl structure with methoxy substituents |
| Molecular Weight | 418.53 g/mol | |
| Solubility | Insoluble in water; soluble in organic solvents (toluene, xylene, chlorobenzene, DMF) | Hydrophobic nature ensures excellent polymer compatibility |
| Style | Bis(styryl)biphenyl / Fluorescent Whitening Agent (FBA) | Non-ionic, heat-stable brightener for thermoplastics |
| Purity | ≥ 98.5% - 99.5% (HPLC) | High purity ensures consistent performance and minimal impurities |
| Melting Point | 216-222°C | Excellent thermal stability for melt processing |
| Volatile Content | ≤ 0.5% | Low volatility during processing |
| UV Absorption Maximum | 359-374 nm | Efficient absorption of near-UV radiation |
| Fluorescence Emission | 434 nm (blue-violet) | Characteristic fluorescence for optimal whitening effect |
| Packing | 20 kg per carton; 25/30 kg per fiber drum with PE liner; custom sizes available | Secure, moisture-proof packaging to maintain product integrity |
| Storage Conditions | Store in cool, dry, ventilated warehouse; avoid rain, fire, heat sources, and direct sunlight; keep away from acids and alkalis | Shelf life: 2 years under proper storage conditions |
| Application | PVC, PE, PP, PS, ABS, EVA, TPU, TPR, Synthetic Leather, Paints, Coatings, Inks, Man-Made Fibers | Versatile across multiple industries |
3.Product Application
Plastics & Thermoplastics – Primary Application:
Optical Brightener FP-127 is the preferred whitening agent for a wide range of thermoplastics, offering exceptional performance across both transparent and opaque applications. Its mechanism of action—absorbing UV light and emitting visible blue-violet fluorescence—effectively masks the natural yellow tint of polymers while imparting a brilliant, "whiter-than-white" appearance.
Optical brightener FP-127 is mainly used for Plastic, especially for soft pvc plastic, as well as can use in paints, inks and oil-soluble coatings and other whitening.
Synthetic Leather & Artificial Leather:
FP-127 demonstrates exceptional whitening and brightening effects on synthetic leather products, including PU (polyurethane) and PVC-based artificial leathers . When incorporated into the coating or foaming layer, it delivers:
Uniform, brilliant white appearance
Enhanced color depth and richness when used in combination with pigments
Excellent lightfastness and weathering resistance for automotive and upholstery applications
Improved aesthetic appeal for fashion, footwear, and accessories
Paints, Coatings & Printing Inks:
Optical Brightener FP-127 finds extensive application in surface coating formulations:
Clear Lacquers & Varnishes: Masks natural yellowness in clear coatings, enhancing clarity and brightness.
Pigmented Coatings: Enhances whiteness in white pigmented paints and industrial coatings.
Printing Inks: Provides UV fluorescence effects for security printing and anti-counterfeiting .applications; enhances brightness in colored inks.
Specialty Coatings: Suitable for high-grade industrial finishes and automotive coatings.
Man-Made Fibers:
FP-127 is widely used in the production of synthetic fibers, providing permanent whitening effects incorporated directly into the fiber during manufacturing :
Polyester Fibers: For whitening and brightening polyester textiles and technical fibers
Polyamide (Nylon) Fibers: Effective for both textile-grade and engineering-grade nylon
Acetate Fibers: Provides brightening effects for cellulose acetate applications
Rubber & Adhesives:
The brightener is suitable for:
Rubber Compounds: Enhances the appearance of natural and synthetic rubber products.
Adhesives & Sealants: Provides aesthetic brightening for clear and white adhesive formulations.
TPR (Thermoplastic Rubber): Effective for footwear, automotive, and consumer goods applications.
Fluorescent whitening agent FP-127 has good whitening effect on all kinds of plastics and plastic products, especially on polyvinyl chloride, polypropylene and foamed shoes, foam board, EPS board, Polystyrene Board, the whitening and brightening effect on artificial leather and leather products is especially ideal, and has the advantages of long-term storage without yellowing and fading.
Reference Dosage:
Optical brightener FP-127can be mixed with these plastic particles before the molding and processing of various plastic products:
In Polyvinyl chloride(PVC)
Whitening: 0.01-0.05%(10-50g/100kg material).
Transparent: 0.0001-0.001% (0.1-1g/100kg material).
In Polystyrene(PS)
Brightening: 0.001% (1g/100kg material).
Transparent: 0.0001-0.001%(0.1-1g/100kg material).
In ABS.
0.01-0.05%(10-50g/100kg material).
In Other plastics:
0.01-0.05% of the weight of plastic.
For reference only, the specific additive amount should be used in conjunction with the product, welcome to contact us to get the relevant recommendations!
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.