KALAR® 5275 is a partially cross-linked butyl rubber compound pelletized for easy handling. KALAR® products feature all the performance attributes expected of butyl rubber. KALAR® 5275 is amber in color and is among the tightest cross-linked butyl rubbers of the KALAR® products. It is designed as the starting point for applications that require the maximum resistance to creep and slump. KALAR® 5275 provides good resistance to flow at high temperatures.

Chemical Family: Butyl Rubber

Functions: Binder & Resin, Impact Modifier, Processing Aid

Compatible Polymers & Resins: Butyl Rubber (IIR), Ethylene Propylene Diene Monomer (EPDM)

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Identification & Functionality

Features & Benefits

CASE Ingredients Features
Materials Features
Product Features & Benefits

KALAR® 5275 contains no filler and its tenacity is due to the degree of cross-linking; not reinforcing fillers. This feature permits the compounder the widest formulating latitude. Other key performance benefits include:

  • Elimination of butyl rubber pre-mastication
  • Pellets may be metered to facilitate mixing
  • Requires no vulcanization
  • Readily acceptable in a wide range of solvents
  • Extends with high levels of fillers and plasticizers
  • Compatible with a wide choice of compounding ingredients
  • Compounding economy

Applications & Uses

Application Area
Compatible Polymers & Resins
Plastics & Elastomers End Uses
Product Applications

KALAR® 5275 contains no monomeric materials that often impart an objectionable odor and potential instability under elevated temperature. Although widely used in the sealant industry, KALAR® 5275 is also ideal for a variety of other applications.


Physical Form
Typical Properties
ValueUnitsTest Method / Conditions
Mooney Viscosity (at 127°C)65 - 72-ASTM D1646
Specific Gravity0.92-ASTM D71
Density7.7lb/galASTM D71
Glass Transition Temperature-70.0°C-

Packaging & Availability

Packaging Type
Regional Availability
  • Global (Excluding Russia)
Typical Packaging

KALAR® 5275 is packaged in 50 lb. fiber boxes.

Storage & Handling

Shelf Life
1 Year
  • The suggested handling procedure varies with the desired product.
  • Coatings and adhesives are produced by adding the pellets to a solvent, mixing with a high-speed homogenizer-dispenser, and adding the rest of the ingredients.
  • Caulks and sealants may be mixed in Sigma blade mixers.
  • Stiff compounds may be mixed in a Banbury or on a two-roll rubber mill.
Storage Conditions
  • KALAR® 5275 product may agglomerate or hard-pack within the boxes, however this will have no effect on chemical or physical properties and the product may be used.
  • Store in a cool, dry environment.