Melt Viscosity Window and Slot-Die Coating Defects in SIS 1130 HMPSA

Jusage SIS 1130 is incorporated into hot-melt pressure-sensitive adhesive formulations for case sealing, label stock, and high-speed packaging tapes at polymer loadings of 20–30 wt%. A representative formulation consists of SIS 1130 25 wt%, a pentaerythritol rosin ester with softening point 95 °C at 50 wt%, naphthenic process oil 24.5 wt%, and a hindered phenolic antioxidant at 0.5 wt%. Melt blending is carried out in a jacketed sigma-blade mixer or a co-rotating twin-screw extruder with L/D 40:1 at a discharge temperature of 165–175 °C. The processing window is narrow. Above 185 °C, the unsaturated isoprene midblock undergoes thermo-oxidative chain scission. Below 150 °C, tackifier dispersion remains incomplete and peel values become erratic. Viscosity during slot-die coating is maintained between 5,000 mPa·s and 20,000 mPa·s at 175 °C. Values above 25,000 mPa·s are associated with melt fracture at die lip gaps below 250 µm and with ribbing defects on polyethylene terephthalate backings. Coating weight is controlled at 18–22 g/m² for label stock. Peel adhesion to stainless steel per PSTC-101 typically falls between 15 N/25 mm and 25 N/25 mm after 24 h dwell. Loop tack per ASTM D6195 typically exceeds 20 N/25 mm. Shear adhesion failure temperature is evaluated by ASTM D4498. Formulations with low diblock content give SAFT values above 75 °C. Higher diblock content raises loop tack but depresses SAFT and increases cold flow. Transition-metal stearates should be excluded because they catalyze oxidative degradation of the isoprene midblock. Pre-drying at 60 °C for 2 h is applied when pellets have been stored at relative humidity above 60%. For food packaging label applications, the formulated adhesive is assessed under FDA 21 CFR 175.125 when a functional barrier separates the adhesive from food.

The above values are representative laboratory coating data for a linear SIS with a tackifying resin of softening point 95 °C. They are not product specifications.

In solvent-borne pressure-sensitive adhesive compounding, SIS 1130 is dissolved to 35–40 wt% solids in a toluene/ethyl acetate blend at 80/20 volume ratio before a C5/C9 hydrocarbon tackifier is added at 40–60 phr based on polymer. Dissolution sequence is critical. Adding tackifier before full polymer solvation produces clear-viscous inhomogeneity and gel-like microphases that reduce coating uniformity. The adhesive solution is applied to silicone-coated release liner by comma bar or reverse gravure at line speeds of 20–40 m/min, then dried through a three-zone oven with air temperatures of 60 °C, 80 °C, and 120 °C. Residual toluene content above 500 µg/g in the deposited film reduces room-temperature shear resistance by more than 50% when tested per ASTM D3654. At solids above 45 wt%, comma-bar levelling worsens and transverse coating thickness variation exceeds ±2 µm. Compliance for solvent-borne industrial adhesives falls under REACH. Toluene is restricted under Annex XVII entry 48 only for consumer adhesive applications, while Directive 2010/75/EU applies if solvent recovery capacity is not installed. Terminal products are low-residue masking tapes and polypropylene surface-protection films. Peel from polypropylene after 72 h dwell is kept below 5 N/25 mm to avoid substrate damage, verified by PSTC-101 with a crosshead speed of 300 mm/min.

Why Does SIS 1130 Reduce Low-Temperature Flexibility Loss in Polymer-Modified Bitumen?

SIS 1130 is evaluated in polymer-modified bitumen for self-adhered waterproofing membranes and bridge-deck binders at polymer loadings of 4–8 wt%. The triblock structure is dispersed into penetration-grade bitumen at 170–185 °C using a high-shear rotor-stator mixer at 3,000–5,000 rpm for 90–120 min. Elemental sulfur at 0.1–0.2 wt% is sometimes introduced after polymer dispersion to create a lightly vulcanized network. This raises softening point and elastic recovery. If mixer speed falls below 2,500 rpm, the SIS phase remains as coarse domains larger than 10 µm and storage stability degrades. Softening point is measured by ASTM D36 and increases from a base bitumen value near 50 °C to 80–95 °C after modification. Cold bend temperature per EN 1109 moves from -5 °C to below -15 °C. Storage stability difference in softening point between top and bottom after 3 days at 180 °C is kept within 5 °C per EN 13399. Processing above 195 °C causes gel formation in SIS-modified bitumen. Mixing time beyond 4 h can lead to viscosity increase above 3 Pa·s at 180 °C and pump cavitation. Terminal products are torch-free self-adhered membranes for underground waterproofing and cold-applied bitumen joint sealants. Peel adhesion to concrete of at least 4 N/25 mm at 23 °C is tested by ASTM D903.

When SIS 1130 Is Co-Crosslinked with Acrylate Monomers in EB-Curable Pressure-Sensitive Adhesives

SIS 1130 can be dissolved in a monomer blend of 2-ethylhexyl acrylate and isobornyl acrylate at 30–40 wt% polymer for electron-beam-curable pressure-sensitive adhesives. The formulation is coated on release film and passed under an electron beam at 25–40 kGy. The unsaturation in the isoprene midblock participates in the radical network, raising gel fraction to 60–75% when measured by 96 h Soxhlet extraction in toluene. Doses below 20 kGy produce under-crosslinked films with shear adhesion failure time below 1 h per ASTM D3654. Doses above 60 kGy embrittle the isoprene phase and reduce peel adhesion to stainless steel below 2 N/25 mm per PSTC-101. Nitrogen inerting with residual oxygen below 50 ppm is required. For food packaging laminating adhesives, evaluation is required under FDA 21 CFR 175.105 or FDA 21 CFR 175.125 when the adhesive is separated from food by a functional barrier. In the EU, (EC) No 1935/2004 applies. Terminal products include optically clear film-to-film laminates for flexible packaging and dicing tapes used in semiconductor wafer grinding. Dicing tape adhesives require controlled peel transition after UV exposure. SIS 1130 formulations are adjusted with acrylate monomer content to achieve post-UV peel reduction from 8–12 N/25 mm to 0.5–1.0 N/25 mm. Published data for this specific dicing tape configuration is limited.

In high-solids construction sealant compounding, SIS 1130 is used at 18–25 wt% with calcium carbonate filler at 35–45 wt%, hydrocarbon resin at 20–25 wt%, naphthenic oil at 10–15 wt%, and a silane adhesion promoter at 0.5–1.0 wt%. The compound is produced in a planetary mixer equipped with vacuum deaeration at -0.09 MPa to reduce entrapped air below 2 vol%. Moisture-cure chemistry is not used. The silane acts as a surface-priming adhesion promoter to glass and anodized aluminium. Joint movement capability is evaluated per ISO 11600. The target class is F 25 LM, requiring elastic recovery above 60% after extension. The formulation must not be exposed to amine-containing epoxy primers because residual amines alter the silane condensation equilibrium and reduce adhesion to glass. Application temperature is limited to 5–40 °C. Below 5 °C, viscosity exceeds 1,000 Pa·s and standard caulking guns fail to dispense. Terminal products include expansion-joint sealants for prefabricated building panels and glazing sealants for non-structural facade joints.

Peel Force Decay and Primary Skin Irritation Boundaries for SIS 1130 Wound-Care Laminates

SIS 1130 is screened as a base polymer for skin-contact adhesive layers in wound-care composites and ostomy device faceplates at loadings of 25–30 wt%. The formulation includes a fully hydrogenated tackifier to reduce skin sensitization potential and a liquid paraffin plasticizer at 10–15 wt%. Hot-melt coating is performed at 130–150 °C through a slot die onto a breathable polyurethane film with moisture vapour transmission rate above 1,000 g/m²/24 h per ASTM E96. The adhesive is covered with silicone release liner and converted by rotary die cutting. Peel force on stainless steel per PSTC-101 is adjusted to 2–6 N/25 mm to balance securement and low-trauma removal. Adhesive mass per unit area is kept at 25–35 g/m². Values above 40 g/m² reduce MVTR and increase maceration risk. Medical-grade qualification requires batch-specific testing for cytotoxicity per ISO 10993-5 and primary skin irritation per ISO 10993-10. Jusage SIS 1130 is an industrial-grade polymer. Published data for this specific grade in medical device applications is limited. Formal biocompatibility assessment must be completed on the formulated adhesive rather than the raw polymer. Sterilization by ethylene oxide can be applied at 45–55 °C with relative humidity 50–70%. Gamma irradiation above 25 kGy degrades the isoprene midblock and reduces peel force by more than 30%. Terminal products are bordered wound dressings and ostomy faceplates with skin-contact layers that require clean removal without adhesive residue.