Hot-melt pressure-sensitive adhesive compounding based on Jusage SIS 1170, a linear styrene-isoprene-styrene triblock with styrene mass fraction 17 wt% and diblock content ≤1 wt%, requires selective tackifier loading to maintain the balance between cohesive strength and substrate wetting. A double-arm sigma-blade mixer or co-rotating twin-screw extruder with L/D 40:1 disperses the polystyrene end-blocks into a continuous isoprene/tackifier phase at 150-170 °C; aerobic degradation of the isoprene midblock becomes measurable above 190 °C, and residence time is therefore limited to 20-40 min in batch mixers. The formulation addition window for SIS 1170 is 20-35 wt%, hydrogenated C5 or C9 tackifier 40-60 wt%, naphthenic or paraffinic process oil 10-30 wt%, and hindered phenolic antioxidant 0.5-1.0 wt%. At SIS 1170 loadings below 20 wt%, high-strain cohesive failure occurs because the styrenic network density is insufficient; above 35 wt%, viscosity rises above 80,000 mPa·s at 160 °C, causing die lip build-up and uneven coating stripes. Vacuum devolatilization at -0.08 MPa to -0.095 MPa reduces volatile content below 0.2 wt% before coating. Slot-die coating at 155-165 °C onto silicone release liner or polymer facestock produces adhesive coatweights of 20-150 g/m². Peel adhesion on stainless steel per ASTM D3330/D3330M-04 is typically maintained between 8 and 25 N/25 mm; loop tack per ASTM D6195-03(2019) and static shear per ASTM D3654/D3654M-06(2019) are used for batch release testing. For food-contact packaging tapes and labels, the compounded adhesive falls under FDA 21 CFR 175.105 and FDA 21 CFR 175.125; EU food-contact assessment follows Regulation (EC) No 1935/2004 and, for plastic layers, (EU) No 10/2011. Terminal product types include polypropylene carton sealing tape, paper label stock, freezer-grade labels, surface protection films for stainless steel and glass, and pressure-sensitive lamination films. Pre-drying is not required for SIS 1170 at relative humidity below 60%; polar tackifier resins with moisture content above 0.3 wt% must be dried to prevent bubble formation in the coated adhesive layer.

How Does SIS 1170 Influence Creep Resistance in Hygiene Construction Adhesives?

Continuous hot-melt application in hygiene converting lines uses SIS 1170 at 18-32 wt% with an aliphatic C5 tackifier at 40-55 wt%, white mineral oil at 15-25 wt%, and antioxidant at 0.5-1.0 wt% to produce a low-viscosity network that retains cohesive strength at body temperature. Tackifier content below 40 wt% shifts failure to cohesive fracture at peel rates above 5 m/min, while content above 55 wt% reduces open time and forms char on spiral spray nozzle tips. The adhesive is supplied to multi-bead spiral spray nozzles through heated hoses at 145-165 °C; melt viscosity is controlled within 2,000-8,000 mPa·s at 160 °C by adjusting the oil-to-tackifier ratio. Bonding of polyethylene backsheet film to nonwoven at line speeds of 200-600 m/min uses coatweights of 0.5-5 g/m² and compression nip pressure of 1-4 bar, with open time between 0.01 and 0.05 s. At 37 °C the elastic plateau modulus of the styrenic network suppresses long-term creep, while the tackifier phase lowers loss modulus to permit substrate wetting under fast nip conditions. Standards applicable to finished laminates include ISO 10993-5:2009 and ISO 10993-10:2010 for skin-contact articles, FDA 21 CFR 175.105 for indirect food-contact adhesives, and ASTM D3960-05 for volatile organic content below 0.5 wt%. Terminal product types are baby diapers, adult incontinence briefs, feminine hygiene pads, and mattress underpads. Production-scale failure is observed when polyethylene films containing amine-based slip agents are bonded at low coatweights, because migration to the adhesive interface reduces peel strength; this is corrected by selecting non-amine slip packages or increasing coatweight by 0.5-1.0 g/m².

Melt blending of SIS 1170 into paving-grade bitumen at 3-8 wt% relative to bitumen mass raises the softening point measured by ASTM D36/D36M-14 without requiring sulfur crosslinking in all formulations. Compatibility is sensitive to the maltene fraction of the bitumen; low-maltene paraffinic crude sources require the lower SIS loading and aromatic process oil at 3-4 wt% to prevent visible polymer separation. A rotor-stator high-shear mixer operating at 3,000-5,000 rpm disperses the polymer at 170-185 °C for 30-60 min, followed by low-shear maturation at 160-170 °C for 60-120 min. The addition window includes SIS 1170 at 3-8 wt%, aromatic process oil at 1-4 wt%, and, for storage-stable polymer-modified bitumen, elemental sulfur or sulfur-donor crosslinking agent at 0.05-0.2 wt% when phase stability testing indicates separation. Storage stability is evaluated by the top-to-bottom softening point difference per EN 13399, maintained below 5 °C. The product falls under EN 14023:2010, AASHTO M320-10, and ASTM D5976 where applicable. Terminal product types include porous asphalt mixtures, high-deformation intersection pavements, bridge deck waterproofing membranes, and self-adhesive roofing membranes. If mixing temperature exceeds 190 °C, degraded isoprene can form surface scum and increase storage separation risk; a nitrogen blanket over the mixing vessel is recommended above 180 °C.

When SIS 1170 Is Melt-Blended with Polyolefin Elastomers in Elastic Film

Cast film lines running SIS 1170/polyolefin elastomer blends require distributive mixing elements rather than high-shear kneading blocks because the isoprene block undergoes mechanochemical chain scission at shear rates above 1,000 s⁻¹. A single-screw or twin-screw extruder with L/D between 30:1 and 40:1 uses a barrel temperature profile from 180 °C at the feed section to 210 °C at the flat die, and the film is quenched on a chill roll at 20-35 °C. The formulation addition window is SIS 1170 at 20-45 wt%, polyolefin elastomer at 40-60 wt%, polypropylene carrier resin at 10-20 wt%, and slip/anti-block package at 0.5-1.0 wt%. Oil-free systems are preferred for film clarity; if mineral oil is added above 5 wt%, surface migration can reduce peel bond of subsequently attached adhesive tabs. Draw ratio is controlled between 2:1 and 4:1 before winding at film thickness 40-120 µm. Tensile properties are measured per ASTM D882-18, and tension set after 200% elongation is measured per ASTM D412-16; permanent set is maintained at ≤15% within the specified addition window. Standards for skin-contact and medical articles include ISO 10993-5:2009, ISO 10993-10:2010, and EU 2017/745; products for electronics or consumer goods require RoHS Directive 2011/65/EU and REACH SVHC screening. Terminal product types are elastic ears and side panels for baby diapers, waistbands for adult incontinence products, elastic closures for medical gowns, and disposable bandage wraps. Blocking during film winding occurs when the chill roll exceeds 35 °C; anti-block addition at 0.5 wt% and corona treatment to 38-42 mN/m are used to control roll blocking.

SIS 1170 Oil Gel Rheology in Hot-Melt Sealant Extrusion

Hot-melt sealant extrusion using SIS 1170 oil gels is governed by the plateau modulus of the styrenic network and the viscosity of the extender oil. The formulation addition window is SIS 1170 at 15-25 wt%, hydrogenated C9 tackifier at 20-30 wt%, polybutene or naphthenic oil at 10-20 wt%, calcium carbonate filler at 30-45 wt%, antioxidant at 0.5-1.0 wt%, and optional UV stabilizer at 0.1-0.3 wt%. At filler loading above 45 wt%, melt pressure exceeds 15 MPa and die swell becomes non-linear; calcium carbonate is therefore side-fed after plastication and limited to the specified range. Mixing is performed in a co-rotating twin-screw extruder with L/D 40:1, barrel temperatures 140-160 °C, and a vacuum devolatilization port at -0.08 MPa. Melt pressure at the die is maintained between 5 and 15 MPa for uniform profile dimensions. Melt flow rate measured per ISO 1133-1:2022 at 190 °C with 2.16 kg load is typically 5-15 g/10 min. Product standards include ASTM C920-18a for elastomeric joint sealants, ISO 11600:2002 for building joint sealants, and ASTM D412-16 for tensile properties. Terminal product types include insulating glass edge sealants, general-purpose hot-melt construction sealants, cable joint filling compounds, and vibration damping preforms. The sealant is not recommended for continuous immersion in aromatic solvents or contact with oxidizing acids; the unsaturated isoprene midblock requires antiozonant addition at 0.05-0.1 wt% when ozone exposure is anticipated.

Injection molding of polypropylene-based soft-touch compounds containing SIS 1170 at 10-30 wt% produces overmolded parts with Shore A hardness between 40 and 70 measured per ISO 868:2003. The compounding formulation includes random propylene copolymer at 50-70 wt%, SIS 1170 at 10-30 wt%, additional styrenic or olefinic elastomer at 5-15 wt%, white mineral oil at 5-15 wt%, and antioxidant at 0.3-0.5 wt%. Compounding uses a co-rotating twin-screw extruder with L/D 40:1 and barrel temperatures from 180 °C to 220 °C; injection molding clamp force is selected between 100 and 500 t depending on mold projected area. Melt flow rate per ISO 1133-1:2022 at 230 °C with 2.16 kg load is adjusted by the oil fraction to 10-30 g/10 min for thin-wall filling. Melt strength decreases progressively above 30 wt% SIS 1170; gate blush is observed in thick overmolded sections because the isoprene phase undergoes delayed elastic recovery at the gate. Standards include RoHS Directive 2011/65/EU, REACH SVHC screening, FDA 21 CFR 177.1520 where olefin food-contact compliance is required, and (EU) No 10/2011 for food-contact plastics; toy applications require ASTM F963-23 and EN 71-3:2019+A1:2021 migration limits. Terminal product types are soft-touch grips for kitchen utensils, power tool handles, appliance feet, bottle cap liners, and toy overmolding skins. Drying of the polypropylene carrier is required at 80 °C for 2-4 h if external moisture exceeds 0.1 wt%; excess SIS 1170 above 30 wt% lowers melt strength and can cause gate blush in thick overmolded sections.