| HS Code | 988407 |
| Brand | Jusage |
| Product Name | Jusage Styrene-Isoprene-Styrene (SIS) Block Copolymer 1250L |
| Grade | 1250L |
| Chemical Name | Styrene-Isoprene-Styrene Block Copolymer |
| Polymer Type | SIS Block Copolymer |
| Structure | Linear |
| Appearance | White or light yellow porous pellets |
| Styrene Content | 20 wt% |
| Diblock Content | 50 wt% |
| Volatile Matter | ≤0.7 wt% |
| Ash Content | ≤0.2 wt% |
| Melt Flow Rate | 12 g/10 min (200°C, 5 kg) |
| Tensile Strength | ≥12 MPa |
| Elongation At Break | ≥800% |
| Shore A Hardness | 40 |
| Specific Gravity | 0.93 |
| Solution Viscosity | 1200 mPa·s (25°C, 25% toluene) |
| Yellowness Index | ≤8 |
| Molecular Weight | 200,000 g/mol |
As an accredited Jusage Styrene-Isoprene-Styrene (SIS) Block Copolymer 1250L factory, we enforce strict quality protocols—every batch undergoes rigorous testing to ensure consistent efficacy and safety standards.
| Packing | Jusage SIS 1250L comes in a 1250 L IBC tote with secure cap and clear chemical labeling for safe handling. |
| Container Loading (20′ FCL) | 20′ FCL container loading of Jusage SIS 1250L chemical, with palletized, strapped, and braced cargo for safe ocean transport. |
| Shipping | Jusage SIS 1250L is shipped as a non-hazardous, non-regulated solid, typically in 25 kg multiwall bags or 1250 kg jumbo bags. It is palletized and transported by road, sea, or air under normal conditions. Keep dry and away from direct sunlight and heat. No UN number, hazard class, or packing group applies. |
| Storage | Store Jusage SIS 1250L in a cool, dry, well-ventilated warehouse, away from direct sunlight, heat, sparks, and open flames. Keep containers tightly closed and upright in original packaging. Protect from moisture, acids, alkalis, and strong oxidizers. Maintain storage at 5–30°C and avoid prolonged exposure above 30°C. Do not store near food, feed, or drinking water. Follow first-in-first-out and observe shelf life. |
| Shelf Life | Shelf life is about 12 months when stored unopened in original packaging, cool and dry, away from direct sunlight and moisture. |
When SIS 1250L enters label-stock hot-melt pressure-sensitive adhesive compounding, the grade is typically incorporated at 20–33 wt% of total adhesive mass, with hydrogenated hydrocarbon or rosin ester tackifier at 45–60 wt%, naphthenic or paraffinic process oil at 10–20 wt%, and a hindered phenolic/phosphite antioxidant at 0.3–0.8 wt%, with the tackifier-to-oil ratio adjusted to close the formulation to 100 wt%. Compounding is conducted in a jacketed sigma-blade kneader or a co-rotating twin-screw extruder with L/D ≥ 40 and barrel zones held between 140°C and 165°C, while nitrogen blanketing at 0.2–0.5 bar is maintained to limit oxidative gel formation in the unsaturated polyisoprene mid-block. The molten adhesive is slot-die coated onto silicone-coated release liner at 140–160°C and laminated to facestock at nip pressures of 2–4 N/mm; finished label stock is tested for loop tack by FINAT FTM 9 and for 180° peel adhesion by ASTM D3330/D3330M. Regulatory clearance for indirect food-contact label applications is documented under 21 CFR 175.105, while REACH Regulation (EC) No 1907/2006 Article 33 SVHC screening at a 0.1 wt% threshold is applied to the compounded adhesive. Processing above 180°C for more than 2 h causes chain scission, viscosity loss, and adhesive transfer to the liner surface.
Multi-line construction adhesives for disposable hygiene articles incorporate SIS 1250L at 12–20 wt%, hydrogenated hydrocarbon or rosin ester tackifier at 50–65 wt%, white mineral oil at 15–25 wt%, and antioxidant at 0.2–0.6 wt%, with the oil content trimmed to balance total solids. The downstream operation uses a drum melter and heated hose system at 150–170°C, feeding a multi-bead or spiral-spray applicator at melt pump discharge pressures of 20–40 bar; add-on weights are held at 2–6 g/m² for nonwoven lamination and 8–15 g/m² for elastic strand adhesion. Compliance documentation for the finished article references REACH Regulation (EC) No 1907/2006 Annex XVII PAH restrictions, and when the adhesive layer is not separated from the wearer by a continuous coverstock, skin irritation potential is assessed under ISO 10993-10:2021. The terminal product classes produced on these lines are baby diapers, adult incontinence briefs, and feminine care pads. If melt temperature is raised above 180°C to reduce viscosity, the unsaturated isoprene block undergoes thermal oxidative degradation, leading to viscoelastic phase separation and char deposition on spray nozzle tips; viscosity adjustment is therefore achieved by switching oil grade or tackifier softening point rather than by increasing melt temperature.
In bituminous waterproofing membrane manufacture, the compatibility window between SIS 1250L and penetration-grade bitumen is governed by maltene-to-asphaltene ratio rather than rotor speed alone. The polymer is typically loaded at 6–12 wt% of the filled bitumen compound, with limestone filler at 20–35 wt%, process oil or flux oil at 5–10 wt%, and the remaining balance penetration-grade bitumen; mixing is performed in a high-shear tank at 170–185°C for 2–4 h with rotor tip speeds of 10–15 m/s, followed by a low-shear holding tank staged below 160°C. The compound is coated onto polyester or glass-fibre reinforcement at 3–5 kg/m² and finished into self-adhesive bituminous flashing tapes and reinforced waterproofing sheets. Roofing membrane performance is evaluated according to EN 13707:2004+A2:2009, with low-temperature flexibility per EN 1109:2013 and flow resistance at elevated temperature per EN 1110:2010; cold flexibility is typically assessed at -20°C and flow resistance at 100°C. Thermal loading above 200°C or total hold times exceeding 6 h degrade polyisoprene segments, and high aromatic process oils can swell the polystyrene end-domains, reducing cohesive strength at elevated temperature. Published data for SIS 1250L in this particular self-adhesive membrane configuration is limited, and pilot-scale coating trials are recommended before line qualification.
SIS 1250L dissolves at 30–40 wt% total solids in a solvent blend of toluene, ethyl acetate, and hexane; on dry solids basis, the polymer is incorporated at 25–35 wt%, with alkylphenol or rosin ester tackifier at 40–55 wt% and a hindered phenolic antioxidant at 0.5–1.0 wt%. Dissolution is carried out in an explosion-proof high-speed disperser at 20–25 m/s tip speed for 60–90 min until Brookfield viscosity reaches 2,000–6,000 mPa·s at 25°C per ISO 2555:2018. The downstream process is roll coating or airless spray application to both substrates, followed by forced-air flash-off at 20–30°C for 5–10 min and contact bonding under 0.5–1.0 MPa pressure. The governing compliance constraint is EU Directive 2004/42/EC on VOC limits for adhesives; for furniture and mattress assembly, the finished article must also satisfy REACH Regulation (EC) No 1907/2006 Annex XVII PAH restrictions. Terminal products include laminated upholstery panels, insulation batting, and decorative edge-banding. Moisture above 0.1% in the solvent blend causes gel speck formation, and chlorinated solvents are excluded from the production permit for this downstream segment.
Twin-screw compounding of SIS 1250L into polyolefin-rich TPE compounds requires mapping the shear-heating threshold against melt flow stability per ISO 1133-1:2022. A representative compound comprises SIS 1250L at 30 wt%, polypropylene homopolymer at 18 wt%, paraffinic white oil at 51 wt%, and a stabilizer package at 1.0 wt%, with the SIS loading window for this downstream segment typically held at 25–35 wt%. The co-rotating twin-screw extruder runs at 190–215°C barrel set points and 250–350 min⁻¹ screw speed, with the melt temperature at the die not exceeding 220°C to prevent degradation of the unsaturated isoprene mid-block; strands are pelletized and then injection molded at 180–210°C on presses with clamp force in the 80–150 t range. Regulatory compliance for appliance grommets used in electrical and electronic equipment is governed by EU Directive 2011/65/EU Annex II restricted substances; for general consumer articles such as furniture feet and grips, REACH Regulation (EC) No 1907/2006 Annex XVII is applied at the finished-compound level. For articles intended for prolonged skin contact, ISO 10993-10:2021 skin irritation testing is applied at the finished-compound level. Terminal parts are soft-touch grips, non-slip furniture feet, and resilient appliance grommets. Pre-drying at 60–70°C for 2 h is specified when warehouse relative humidity exceeds 60%, because surface moisture produces foaming and die-lip build-up during compounding. Published data for this specific 1250L grade in USP Class VI pharmaceutical-contact applications is limited.
Packaging tape HMPSA formulations based on SIS 1250L use polymer loadings of 25–35 wt%, C5/C9 aliphatic-aromatic tackifier at 40–55 wt%, liquid polybutene or white mineral oil at 5–15 wt%, and antioxidant at 0.3–0.6 wt%, with the tackifier-to-oil balance adjusted to 100 wt%. The adhesive is compounded in an extruder at 150–170°C and coated onto biaxially oriented polypropylene film by calendered melt coating at 15–25 g/m²; finished tape is evaluated for 180° peel adhesion at 300 mm/min per ASTM D3330/D3330M and loop tack per PSTC-16. Regulatory conformity for packaging tape in the EU is documented under REACH Regulation (EC) No 1907/2006, with Article 33 SVHC content kept below 0.1 wt%; where tape contacts dry food in transit, 21 CFR 175.105 applies to the adhesive component. Terminal product types are BOPP carton-sealing tapes and pallet strapping tapes. A known production conflict is viscosity fluctuation caused by tackifier lot variation, which can shift peel force by 10–15% unless the tackifier softening point is held within ±2°C of the qualification value.
Competitive Jusage Styrene-Isoprene-Styrene (SIS) Block Copolymer 1250L prices that fit your budget—flexible terms and customized quotes for every order.
For samples, pricing, or more information, please contact us at +8615371019725 or mail to sales7@alchemist-chem.com.
We will respond to you as soon as possible.
Tel: +8615371019725
Email: sales7@alchemist-chem.com
Flexible payment, competitive price, premium service - Inquire now!
Jusage SIS 1250L is a linear styrene-isoprene-styrene triblock copolymer supplied as a porous pellet or dense crumb. The product is intended for hot-melt pressure-sensitive adhesive compounding, solvent-borne PSAs, and tackifier-modified polymer systems. Under the morphology of phase-separated polystyrene end blocks dispersed in a continuous polyisoprene matrix, the grade develops elastomeric recovery and pressure-sensitive surface tack without chemical crosslinking. Representative specification values include a styrene mass fraction of 15 wt%, a diblock content of 30 wt%, a melt flow rate of 10 g/10 min at 200 °C/5 kg according to ASTM D1238-20, and Shore A hardness of 45 according to ASTM D2240-15. Published tensile data for this exact configuration are limited; values reported for comparable SIS grades with equivalent styrene content fall between 8 MPa and 14 MPa when measured under ISO 527-2:2012.
The low styrene mass fraction and the 30 wt% diblock fraction define the property profile. Polystyrene end blocks provide pseudo-crosslinks at service temperatures below 95 °C; the polyisoprene midblock segment exhibits a glass transition near -60 °C. The diblock fraction, consisting of uncoupled styrene-isoprene short chains, lowers the plateau modulus and accelerates bond formation on low-energy surfaces such as polyethylene and polypropylene. In contrast, a low-diblock SIS grade with diblock content below 5 wt% produces higher shear resistance but requires longer open time and higher coating temperature. The L suffix in the 1250L designation corresponds to a lower melt viscosity and lower hardness relative to non-L SIS 1250 grades. Where a non-L 1250 may exhibit a melt flow rate near 6 g/10 min and Shore A hardness near 50, the L variant shifts to approximately 10 g/10 min and 45 Shore A. This difference is produced by controlling coupling efficiency and diblock content during anionic polymerization.
In hot-melt coating, the product is processed on slot-die lines with extruder barrel profiles between 130 °C and 180 °C. The unsaturated polyisoprene midblock is thermally sensitive; residence times above 200 °C promote chain scission, gel formation, and color development. Equipment suitable for production-scale compounding includes co-rotating twin-screw extruders with L/D ratios of 32:1 to 48:1, vacuum venting, and gear-pump discharge. Nitrogen blanketing of the adhesive feed hopper is recommended when the line operates above 170 °C for more than 2 h. Melt flow stability is monitored by ASTM D1238-20; a shift of more than 15 % from the initial melt flow rate indicates thermal degradation or inadequate antioxidant dispersion. A hindered phenol phosphite antioxidant package at 0.3–0.8 phr is typically required for hot-melt compounding, but amine-based stabilizers should be avoided because they can darken the unsaturated isoprene segment during prolonged melt hold.
Moisture control is less critical for the SIS polymer itself than for the tackifier resin. Hydrogenated rosin esters and terpene resins with acid numbers above 15 mg KOH/g may require vacuum drying at 90 °C to residual moisture below 0.1 wt% before blending. At relative humidity above 60 %, undried rosin ester can hydrolyze in the melt tank, causing foaming, die streaks, and reduced clarity in the finished adhesive film. Production-scale hot-melt lines have reported that maintaining melt temperature below 180 °C reduces char formation in gear pumps and slot-die lips, although published field data for this specific grade is limited and line performance should be verified with a pilot run.
In a typical HMPSA formulation, SIS 1250L is combined with 80–120 phr of a C5 aliphatic hydrocarbon resin or hydrogenated rosin ester and 0–20 phr of naphthenic or white mineral oil. The high diblock content reduces the cohesive energy of the adhesive network; therefore, tackifier selection must compensate for shear strength without sacrificing tack. Loop tack is characterized according to ASTM D6195-03(2019), and 180° peel adhesion is measured according to ASTM D3330/D3330M-04(2018). Holding power and shear adhesion failure temperature are evaluated with PSTC-107 or equivalent static shear methods. Formulation data from similar SIS grades indicate that increasing the tackifier loading from 80 phr to 120 phr raises the glass transition temperature of the mixed adhesive phase by approximately 10–20 °C and reduces 180° peel on low-density polyethylene by 20–40 %. Published data for this specific configuration is limited; these trends should be verified for each resin batch.
Aromatic C9 hydrocarbon resins should be used at loadings below 20 phr because their solubility parameter is poorly matched to the polyisoprene midblock. Phase separation can appear as haze, decreased tack, or a sudden drop in static shear. Compatibility screening by dynamic mechanical analysis or haze measurement after 24 h at 25 °C is advisable before production qualification. Conversely, hydrogenated rosin esters with low acid number and C5 aliphatic resins generally produce clear melts and stable adhesive performance when the mixing temperature remains between 150 °C and 170 °C.
The table below summarizes representative property differences between Jusage SIS 1250L, a low-diblock SIS with similar styrene content, and a high-styrene SIS used for higher shear tape adhesives. All values are representative published figures; exact lot-level values must be obtained from the certificate of analysis for each shipment.
| Property | Test Method | SIS 1250L | Low-Diblock SIS | High-Styrene SIS |
|---|---|---|---|---|
| Styrene content | ISO 11358-1 | 15 wt% | 15 wt% | 22 wt% |
| Diblock content | Internal GPC | 30 wt% | <5 wt% | <5 wt% |
| Melt flow rate at 200 °C/5 kg | ASTM D1238-20 | 10 g/10 min | 9 g/10 min | 8 g/10 min |
| Shore A hardness | ASTM D2240-15 | 45 | 48 | 65 |
| Tensile strength | ISO 527-2:2012 | 10 MPa | 18 MPa | 22 MPa |
| Elongation at break | ISO 527-2:2012 | 900 % | 800 % | 700 % |
The primary functional difference is the elevated diblock content of SIS 1250L. This fraction depresses the rubbery plateau modulus and enhances initial tack development, but lowers shear adhesion failure temperature and static load-bearing capacity. When compared with high-styrene SIS grades, SIS 1250L offers lower melt viscosity and better wetting on polyolefin substrates, but its peel adhesion on steel typically remains lower at room temperature because the lower polystyrene content reduces the energy dissipation during adhesive fibril extension. Compared with low-diblock SIS, SIS 1250L also exhibits faster pressure-sensitive bond formation on curved or irregular surfaces, which is relevant for tamper-evident labels and flexible packaging ream closures.
Reformulation from a low-diblock SIS to SIS 1250L generally requires reducing tackifier resin loading by 10–20 % and increasing mixing time to achieve a homogeneous melt. The higher diblock content acts as a compatibilizer but also dilutes the load-bearing polystyrene network; as a result, static shear resistance declines if the formulation is not adjusted. Production-scale coating lines have observed that SIS 1250L-containing adhesives exhibit lower meniscus breakage and smoother coating weight control at line speeds above 150 m/min, provided the melt temperature is held at 160–170 °C. This behavior is attributed to the lower extensional viscosity of the high-diblock melt. For adhesion to corrugated board under cold storage, the product is typically formulated with a higher tackifier ratio than a low-diblock grade to compensate for reduced cohesive strength at 4 °C.
For solvent-borne PSA applications, SIS 1250L is dissolved in toluene, ethyl acetate, cyclohexane, or mixed aromatic/aliphatic solvents at solids contents from 25 wt% to 40 wt%. Solution viscosity depends on solvent composition and diblock content; the high diblock fraction tends to lower solution viscosity at equivalent solids compared with low-diblock SIS. Coating is performed by comma bar or slot-die at wet film thicknesses corresponding to dry adhesive coat weights of 18–30 g/m². Residual solvent must be reduced below 0.1 % by oven drying to avoid plasticization and label lifting. Flash-off profiles above 90 °C can induce surface skinning on large format labels, so ramp drying is preferred.
The operational boundaries of SIS 1250L include limited UV stability and oxidative resistance because the polyisoprene midblock is unsaturated. Applications requiring prolonged outdoor exposure are generally not specified for this grade. Storage should be in sealed containers below 30 °C; prolonged storage above 40 °C may increase gel content and reduce diblock utility. For food-contact adhesive applications, verification is required under FDA 21 CFR 175.105 and European Framework Regulation (EC) No 1935/2004 before use. REACH and RoHS compliance is lot-specific and should be confirmed by the supplier through documented test reports.
