Abstract
Bis[3-(triethoxysilyl)propyl]tetrasulfide (CAS No. 40372-72-3), silane coupling agent KH-69, is a bifunctional, sulfur-containing organosilane for rubber applications in combination with white fillers containing silanol groups.

Identification
Name: Bis[3-(triethoxysilyl)propyl]tetrasulfide
Synonyms: Bis-(3-(triethoxysilyl)-propyl)-tetrasulfane
Molecular Formula: C18H42O6S4Si2
Molecular Weight: 538.94
CAS Registry Number: 40372-72-3
EINECS: 254-896-5

Equivalents
Momentive (formerly OSi Specialties ) Silquest A-1289  
Dow Corning Z-6940  
ShinEtsu KBE-846  
EVONIK Degussa Si 69  
UCT Specialties (formerly Petrarch) B2494

Properties
Density: 1.069
Sulfur content: ≥ 22
Flash point: 100 C degree
Water solubility: REACTS

Application
Bis[3-(triethoxysilyl)propyl]tetrasulfide (CAS No. 40372-72-3), silane coupling agent KH-69, reacts with fillers containing silanol groups during mixing and with the polymer during the vulcanization process under formation of covalent chemical bonds. This imparts better tensile strength, higher module, reduced compression set, increased abrasion resistance and optimized dynamic properties. KH-69 is used in many applications where white fillers containing silanol groups are involved and optimum technical properties are required.
1. Tires: An excellent reinforcing agent in tires to reduce heat built-up, reduce rolling resistance and improve the tires wet grip.
2. Shoe Soles: Generally applicable silane for improving abrasion resistance of sole compounds containing precipitated silica.
3. Mechanical Rubber Goods: General use silane for achieving good dynamic properties, low compression set and high abrasion resistance in mixtures containing white fillers.
4. Adhesives and sealants: An excellent adhesion promoter to glass, aluminum, steel and other inorganic surface in polysulfide, nitrile and other rubber adhesives, sealants and coatings.