In hot-melt pressure-sensitive adhesive compounding, Globalprene® SBS 1485 is incorporated at 20–45 phr as the elastomeric network former because its styrene end-blocks retain physical crosslinks at service temperatures below approximately 90°C, while the butadiene mid-block contributes tack after melt blending with hydrogenated C5 or C9 tackifying resins and naphthenic or paraffinic process oil. Continuous production on a co-rotating twin-screw extruder with L/D 40:1 or higher is generally preferred when throughput exceeds 500 kg/h; barrel temperatures are profiled from 120°C in the feed section to 165°C at the die, with melt temperature held below 180°C to avoid gel particle formation from double-bond degradation. Melt viscosity under ASTM D3236-14 using a Brookfield RVT Thermosel with SC4-27 spindle at 160°C typically falls between 8,000 mPa·s and 25,000 mPa·s for blends containing 30 wt% tackifier and 15 wt% oil; below 8,000 mPa·s, slot-die coaters operating above 150 m/min may exhibit die-edge build-up and irregular transfer onto silicone release liner. Coated onto 36 µm PET film at 18–22 g/m², loop tack is tested under ASTM D6195-03 and 180° peel under ASTM D3330/D3330M-04. Peel adhesion of 3–6 N/25 mm is attainable on stainless steel, but adhesion to untreated low-density polyethylene can fall below 1 N/25 mm unless surface energy is raised by corona treatment to 42–48 dyn/cm. Shear holding is monitored by ASTM D3654/D3654M-06; failure at 70°C with a 1 kg load inside 24 h typically signals resin or oil exudation rather than insufficient SBS loading. The diblock fraction in SBS 1485, where present, acts as a built-in viscosity diluent and can stabilize interfacial phase distribution during storage at 50°C; published data for the exact diblock proportion of this grade is limited.

Why Does Storage-Stable Polymer-Modified Bitumen Require High-Shear Dispersion of 1485?

Because the maltenes fraction of penetration-grade bitumen must migrate into the butadiene mid-block before a continuous polymer network can develop, Globalprene® SBS 1485 is swollen in a 50/70 pen or 70/100 pen base bitumen at 180–195°C under high-shear mixing rather than simple paddle agitation. Road-paving formulations commonly use 3–6 wt% SBS, while stress-absorbing membrane interlayers may require 6–12 wt% depending on the saturates-to-aromatics ratio of the base bitumen and the target softening point. A rotor-stator mill such as the Silverson GX5 operating at 3,500–5,000 rpm is used during a 45–90 min dispersion window; within this stage the maltenes swell the butadiene domain, while the styrene domains remain below their glass transition and create a physically crosslinked polymer-rich phase. The ring-and-ball softening point measured by EN 1427 typically shifts from 46–52°C for unmodified bitumen to 65–85°C after modification. Prolonged mixing beyond 120 min at temperatures above 200°C can initiate chain scission and progressively erode elastic recovery. Storage stability is evaluated by EN 13399, with a softening point difference after 72 h at 180°C of less than 5°C required in many European highway tenders; non-stabilized high-oil systems may exceed 10°C separation. Elastic recovery under EN 13398 at 25°C commonly increases from below 20% for neat bitumen to above 70% for a fully dispersed SBS network at 5 wt% polymer. Low-temperature flexibility is estimated by Fraass breaking point according to EN 12593; a well-dispersed SBS-modified binder can depress the base bitumen break point by 8–15°C. The following matrix summarizes typical specification windows used in European PMB tender documents.

Property	Test method	Typical specification window
Softening point, ring and ball	EN 1427	65–85°C
Penetration at 25°C	EN 1426	20–70 dmm
Elastic recovery at 25°C	EN 13398	≥ 70%
Storage stability, softening point difference	EN 13399	≤ 5°C
Fraass breaking point	EN 12593	≤ -10°C

The same polymer-bitumen system is further compounded for waterproofing membrane manufacture at 8–15 wt% SBS with limestone or talc fillers at 20–35 wt%. Calendering at 110–130°C requires compound viscosity low enough to prevent tearing of the polyester mat; dimensional stability and cold flexibility are then assessed under ASTM D5147/D5147M-18 and ASTM D146/D146M-04.Solvent-borne contact adhesive manufacture uses Globalprene® SBS 1485 at 15–25 wt% solids dissolved in blends of toluene, cyclohexane, and methyl ethyl ketone at ratios near 3:3:1 or 2:2:1. In the initial cold-soak stage, jacketed stainless-steel reactors with low-speed anchor agitation allow solvent to diffuse into the polymer without forming lumpy aggregates; a high-speed disperser at 800–1,500 rpm then completes dissolution over 4–8 h. Solvent balance is critical because toluene-rich systems preserve styrene domain association, while high MEK fractions selectively attack the polystyrene phase and raise solution viscosity beyond 2,000 mPa·s at 25°C. Before application by air-assisted spray or roller coater, the solution is adjusted to 250–800 mPa·s at 23°C. Open time on porous substrates at 23°C and 50% RH ranges from 2 min to 8 min depending on dry film thickness; contact adhesion is established after forced-air drying at 50–60°C for 3–5 min. Cohesion after 7 days is measured by EN 205 or ASTM D3654/D3654M-06; lap shear values on beech wood above 2.0 MPa are typical when dry adhesive thickness is below 150 µm. At relative humidity above 70%, condensation on the roller stock or in the flash-off zone can produce microvoids that reduce final cohesive strength. Chlorinated tackifiers at levels above 10 phr may display phase separation with SBS 1485 and form surface haze; nitrile rubber and chloroprene-based recipes are generally incompatible.

When SBS 1485 Feeds a Hot-Runner Injection Mould for Footwear Compounds

Compounding of injection-moulded footwear outsole and midsole compounds around Globalprene® SBS 1485 typically includes naphthenic or paraffinic oil at 30–80 phr, general-purpose polystyrene at 10–25 phr, and calcium carbonate at 20–50 phr. A co-rotating twin-screw extruder with L/D 36:1 to 44:1 and barrel temperatures from 150°C to 175°C is used for dispersion; melt temperatures above 185°C can generate yellowing and reduced tensile strength from butadiene unsaturation. Pre-drying is not normally required below 0.05 wt% absorbed moisture, but at relative humidity above 75% hopper residence beyond 2 h may produce surface porosity in the finished sole. Injection moulding is performed on a reciprocating-screw machine with clamp force between 80 t and 180 t, nozzle temperatures of 165–180°C, and hydraulic injection pressure of 40–80 bar. Mould temperature is maintained at 25–50°C; above 55°C the part can adhere to the core and surface flow lines may become visible. Hardness after 24 h conditioning is measured by ASTM D2240-15 on a 6 mm plaque, with Shore A values of 45–70 typical for oil-extended formulations. Tensile strength and elongation under ISO 37:2017 fall between 5–12 MPa and 500–900%, respectively, for oil-rich compounds. Abrasion resistance by DIN 53516 is generally 150–350 mm³ loss, though the exact value depends on filler particle size and anti-wear additives. Flex crack acceptance uses ASTM D1052-09; early crack nucleation at the groove can occur when high-diblock grades are used, but published comparative data for SBS 1485 against low-diblock grades is limited. Where compression set below 35% at 70°C is specified, a sulfur-based cure system of 1.5–2.5 phr sulfur with thiazole accelerators may be introduced; a moving-die rheometer at 160°C then shows a torque increase of 2–4 dN·m over 10 min.On a calendering line for polyester-reinforced SBS-modified bitumen waterproofing membranes, Globalprene® SBS 1485 is first dispersed in bitumen through a high-shear mixer at 175–190°C, then transferred to a two-roll calender or spreader for sheet formation. Compound viscosity at 140°C must remain below 15,000 mPa·s to avoid tearing the polyester mat; filler addition at 20–35 wt% provides reflow resistance during torch application. Finished membrane thickness is usually 3–5 mm for torch-applied sheets and 1.5–3 mm for self-adhesive variants. Cold bend resistance is evaluated by EN 1109; a fully developed SBS network can meet -15°C to -25°C bending without cracking. Dimensional stability at 80°C for 24 h under EN 1107-1 is maintained below 0.5% shrinkage. During torch application, the exposed surface encounters localized melt temperatures of 200–250°C at a 100–150 mm flame distance without cohesive failure; oil migration to lap zones can reduce peel resistance below 1.0 N/mm. Reclaimed APP-modified selvage should not exceed 10 wt% regrind in SBS-dominated compounds because the mixed polymer phases can shift the glass transition of the continuous bitumen phase and increase cold-crack temperature.Low-temperature impact modification of polypropylene-based injection moulding grades is an application where SBS 1485 is compounded into homopolymer PP at 5–20 wt% to reduce brittle failure. Melt blending is carried out on a co-rotating twin-screw extruder with PP pellets fed at the main throat and SBS 1485 introduced by side-stuffer or masterbatch; melt temperature is controlled at 190–210°C, with residence above 210°C limited to under 10 min. Notched Izod impact strength per ISO 180:2019 can improve from 2–3 kJ/m² for neat homopolymer PP to 8–15 kJ/m² at -20°C when the SBS domain size is below 2 µm. Domain refinement is governed by screw configuration with at least two intensive kneading blocks and a controlled melt profile from 180°C to 205°C. Flexural modulus under ISO 178:2019 decreases from roughly 1,500 MPa to 1,000–1,200 MPa, so the chosen part specification must tolerate reduced stiffness. If regrind content exceeds 20 wt%, addition of 5–10 wt% coupling agent or ethylene-octene elastomer may be required to recover low-temperature impact. Strand pelletizing is stable when water-bath temperature remains below 35°C and die pressure stays below 30 bar; published data for SBS 1485 in PP impact modification is less extensive than for SEBS grades.