Energy savings plus mechanical reinforcement and rheology control

2K, Variable Tack Poly bd Based Polyurethane Self-Adhesive (A) by Cray Valley

Adhesives Formulation

Applicable Type

Polyurethane Adhesives

Applicable Base Polymer

Polyurethanes

Applicable Industrial Sectors

Automotive , Buildings & constructions

Applicable Base Polymer Properties

Poly bd resin-based polyurethanes can be formulated to make self-adhesive systems. Such systems may contain tackifying resins or asphalt. The key to prepare such a product is to cure the system using a NCO index of less than 1 (preferably between 0.65 and 0.8). This can lead to a very good self adhesive product. Further, since the glass transition temperature of the Poly bd resin is very low, the tack is maintained at low temperatures, allowing contractors to work under winter-like weather conditions. Since this is a thermoset system, it also maintains its integrity at high temperature with excellent sag and chemical resistance.

Typical Formulation Ingredients

Phase

Ingredient

Parts by weight

A (Polyol Component):

Polybutadiene resin (Poly bd R45HTLO, Cray Valley)

xxxxx

A (Polyol Component):

Asphalt AA4909 (77 pen.)

xxxxx

A (Polyol Component):

White mineral oil (Renoil, Renkert Oil)

xxxxx

A (Polyol Component):

Dibutyltin dilaurate catalyst (T-12, Dabco)

xxxxx

B (Isocyanate Component):

Modified diphenylmethane diisocyanate (Isonate 143, Dow Chemical)

xxxx

Typical Properties

Properties

There appears to be no significant difference in performance of adhesives based upon either Isonate 143L or Mondur MRS 2

Low temperature flexibility (due to low Tg of Poly bd)

High temperature resistance (due to crosslinking)

Good chemical resistance (dependent on asphalt concentration)

Good adhesion to construction materials

Compatibility with high loading of fillers

Processing

Resulting Properties

The formulations above are for general purpose two component asphalt filled polyurethane adhesives based on polybutadiene polyol. Using polybutadiene polyol will provide much better hydrolytic stability than other conventional polyols (e.g., polyester or polyether). Often additives are not required to provide flexibility or toughness as in the case of epoxy formulations. Polyurethanes have the capability of providing these properties through manipulation of the resulting molecule by proper choice of isocyanate and polyol. However, additives are used mainly to stabilize the adhesive relative to moisture, oxidation, UV, etc.

(Source: Cray Valley)

Tips and Tricks

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