GENIOSIL® XB 502

• Building & Construction Adhesives
• Wood-to-Wood Bonding
• Industrial Adhesives
• Adhesives
• Do It Yourself

• GENIOSIL® XB 502 dissolves readily in standard organic solvents. It is virtually insoluble in aqueous media, and reacts slowly releasing methanol and forming a resinous deposit. Despite its highly reactive terminal groups, uncatalyzed GENIOSIL® XB 502 is stable in air for several days.
• However, its reactivity with water or atmospheric humidity must be taken into account during storage and processing, since the material will slowly start to condense. GENIOSIL® XB 502 can be formulated by conventional methods and mixing processes.
• The formulation composition depends on the required property profile. GENIOSIL® XB 502 can be formulated with a variety of fillers. The range starts with oxides, such as aluminum hydroxide, quartz powders or pyrogenic silica, and extends to coated and uncoated chalks.
• The type and amount depends on the mechanical needs as well the desired thixotropy. Water scavengers can be added to stabilize the formulations against premature curing as this is moisture-curing technology. Therefore exclusion of moisture during compounding and storage is necessary.
• GENIOSIL® XL 10 or GENIOSIL® XL 70 are particularly suitable scavengers. Any type of plasticizer can be used to further lower the viscosity. In order to plasticize a GENIOSIL® XB 502 based formulation it is recommended to use any type of silane modified polymer e.g. GENIOSIL® STP-E10. Antioxidants, UV- and lightstabilizers are mandatory to ensure durable sealants and adhesives.
• The amount and type of stabilizer depends on application needs. Curing of GENIOSIL® XB 502 requires a catalyst that does not necessarily have to be organo-metallic. However dioctyl tin may be used if required. Catalysis can also be accelerated with titanium compounds as well as inorganic (phosphoric) or organic (tartaric) acids.
• Primarily, we recommend using an amine catalyst, and adjusting the skinformation time by varying the amount of aminosilane used. GENIOSIL® GF 9 and GENIOSIL® GF 95 have proven particularly advantageous here. In particular, GENIOSIL® GF 95 can attain improved water resistance, which can further be increased by the addition of epoxy silanes.

Surface Treatment

Always apply the formulation to clean and dry surfaces. GENIOSIL® XB 502 is used as a reactive binder for adhesives, potting compounds and coatings.

Application

• Curing takes places at ambient temperature in the presence of both moisture and catalyst. Depending on the formulation, either prepared as onepart or two-part systems, it will give good adhesion to a wide variety of substrates even without pretreatment.
• Adhesives can be formulated having high lap-shear strength (< 15 N/mm²) on a wide variety of substrates.
• With certain substrates, modifying the elasticity of the GENIOSIL® XB 502 containing binder is advisable. Based on the model formulation using a filler (1 : 1), with 2.5 % GENIOSIL® GF 9 as the catalyst, the lap-shear-strength of beech/beech and aluminum/aluminum test specimens was determined.
• While GENIOSIL® XB 502 is ideal for bonding wood, metals can be very readily bonded when GENIOSIL XB 502 is blended with GENIOSIL® STP-E10 at a ratio of 3 : 1.

Further state-of-the art bonding

• Wood
• Stone
• Metal
• Bonding of dissimilar substrates (e.g. Wood/metal, metal/concrete)

GENIOSIL® XB 502 is silicon reinforced polyether-based silane-terminated polymer suitable as a binder in moisture curing formulations. It is a transparent low-viscosity binder and the resultant adhesives display hardness in the high Shore D range when cured. This polymer complements the elastic binder range such as GENIOSIL® STP-E10 and can be readily mixed with this product group at various ratios in order to tailor the properties to the respective application. GENIOSIL® XB 502 based on alpha technology, which means a structural proximity of a nitrogen atom to the moisture active silicon atom. It hydrolyzes in the presence of moisture to finally form a stable siloxane network initiated by mild catalysis as opposed to heavy metal ions. Formulations are characterized by the following advantages.

 
• Simple compounding with conventional auxiliaries
 
• Plasticizer free if desirable
 
• Transparent systems
 
• Good mechanics
 
• Long shelf life
 
• Hardness in the Shore D range
 
• Good adhesion to metals, glass and ceramics
 
• Non-bubbling
 
• Isocyanate, tin and solvent-free - Formulation of water resistant products possible
 
• Good heat stability