| HS Code | 536689 |
| Product Name | S-LEC BX-1 |
| Material | Polyvinyl butyral (PVB) interlayer film |
| Film Type | Acoustic interlayer for laminated glass |
| Thickness Mm | 0.76 |
| Density G Cm3 | 1.07 |
| Visible Light Transmittance Percent | >90 |
| Haze Percent | <0.5 |
| Uv Cutoff Wavelength Nm | 380 |
| Tensile Strength Mpa | >=20 |
| Elongation At Break Percent | >=250 |
| Glass Transition Temperature Degc | 30 |
| Adhesion To Glass N 25mm | 8 to 15 |
| Sound Reduction Index Db | >35 at 2000 Hz |
| Moisture Absorption Percent | <2 |
| Storage Temperature Degc | 5 to 25 |
| Shelf Life Months | 6 |
As an accredited S-LEC BX-1 factory, we enforce strict quality protocols—every batch undergoes rigorous testing to ensure consistent efficacy and safety standards.
| Packing | S-LEC BX-1 is supplied in 25 kg net sealed multi-layer paper bags, ensuring moisture protection and safe handling. |
| Container Loading (20′ FCL) | S-LEC BX-1 packed in 20′ FCL, palletized and secured, full container load, no co-loading, ensuring safe transport. |
| Shipping | S-LEC BX-1 is a polyvinyl butyral resin shipped in sealed, moisture-proof packaging to prevent clumping and degradation. Transport in clean, dry containers away from direct sunlight and high humidity. Standard non-hazardous chemical handling applies; keep packages upright and avoid puncturing during loading and unloading. |
| Storage | Store S-LEC BX-1 in a cool, dry, well-ventilated area away from direct sunlight, heat sources, and ignition sources. Keep containers tightly sealed to prevent moisture absorption and contamination. Avoid prolonged storage at high temperatures or humidity. Maintain moderate ambient conditions, and inventory rotation is recommended to ensure freshness and product consistency. |
| Shelf Life | S-LEC BX-1 has a typical shelf life of two years when stored in original, sealed containers under cool, dry conditions. |
In multilayer ceramic capacitor tape casting, S-LEC BX-1 is introduced as a pyrolytically removable binder for BaTiO₃-based dielectric slurries, with hydroxyl content typically 20–24 wt% and butyral content 68–72 wt% on the certificate of analysis. Glass transition temperature measured by differential scanning calorimetry per ISO 11357-2 falls between 58°C and 65°C, which sets the upper drying plateau before debinding. A representative production batch consists of 100 parts BaTiO₃ powder with mean particle size 0.3–0.5 μm, 9–14 phr S-LEC BX-1, 2–5 phr polyethylene glycol 400 as plasticizer, 0.5–1.5 phr polycarboxylate dispersant, and 70–90 phr solvent blend of methyl ethyl ketone and ethanol at 60:40 by weight. The resin is pre-dissolved at 30–35°C under cowles blade agitation at 1,000–1,500 rpm for 4–6 h, then filtered through a 1 μm polypropylene cartridge to remove gel bodies. Slurry viscosity after 24 h ageing is controlled between 1,500 and 3,500 mPa·s on a Brookfield RV at 20°C and 20 rpm; lower viscosity causes striations from the doctor blade, while higher viscosity traps air even after 0.1 bar vacuum deaeration for 8 h. Tape casting uses a carrier film speed of 0.8–2.5 m/min, doctor blade gap 100–180 μm, and three-zone drying at 60°C, 80°C, and 95°C. Residual solvent after drying is checked by thermogravimetric analysis, with weight loss below 0.2 wt% from 30°C to 120°C. Laminated green sheets are pressed at 60–80°C and 20–40 MPa for 5–10 min, with layer count commonly 200–500 for high-capacitance MLCC bodies. Binder burnout in air proceeds at 2°C/min to 350°C with a 60 min hold, followed by 0.5°C/min to 550°C with a 120 min hold. Residual carbon below 0.05 wt% by combustion infrared detection is required to avoid insulation resistance degradation in X7R and Y5V dielectrics. A process conflict arises because the hydroxyl groups that provide ceramic wetting also absorb moisture at relative humidity above 60%; slurry temperature should therefore be kept below 25°C and solvent water content below 0.3 wt%, otherwise viscosity drift exceeds ±10% and tape thickness control falls outside ±5 μm.
| Component | Loading range | Function |
|---|---|---|
| BaTiO₃ powder | 100 parts | dielectric filler |
| S-LEC BX-1 | 9–14 phr | thermoplastic binder |
| Polyethylene glycol 400 | 2–5 phr | plasticizer |
| Polycarboxylate dispersant | 0.5–1.5 phr | particle dispersion |
| Methyl ethyl ketone:ethanol 60:40 | 70–90 phr | solvent system |
Solvent retention in the printed film is controlled by the evaporation gradient of a ternary blend: ethanol, ethyl acetate, and methoxypropanol at 55–65:20–30:5–10 by weight. S-LEC BX-1 is dissolved at 8–12 wt% total solids, producing a Shell cup 2 viscosity of 150–450 mPa·s at 25°C. Addition of 5–7 wt% PVB binder to a TiO₂-based white ink changes BOPP surface adhesion compared with nitrocellulose-only systems; cross-hatch tape pull per ASTM D3359 retains class 5B after 24 h at 25°C and 50% RH, whereas the same ink without PVB falls to class 0B on untreated film. Corona discharge should raise surface energy to 42–46 mN/m as checked by dyne solutions per ASTM D2578. Lamination bond strength after dry-bond lamination to metallized PET is measured per ASTM F88 using 25 mm strips and 500 mm/min jaw speed, with values of 2.5–4.0 N/15 mm; failure mode is ink-splitting rather than adhesive delamination. Drying tunnel air temperature is set at 40–70°C with airflow 20–40 m/s; residual solvent in printed film should remain below 10 mg/m² by gas chromatographic headspace analysis. For indirect food-contact printed flexible packaging, EU Regulation 10/2011 is applied with overall migration limit 10 mg/dm² using simulant E and 40°C/10 days conditions, while extractable lead, cadmium, mercury, and chromium VI remain subject to the sum limit of 100 mg/kg under EU Directive 94/62/EC. Specific conformity for S-LEC BX-1 based formulations must be verified against current positive lists and resin vendor documentation.
| Standard / regulation | Test method | Typical requirement |
|---|---|---|
| EU Regulation 10/2011 | Overall migration, simulant E | 10 mg/dm² |
| US FDA 21 CFR 175.300 | Resinous and polymeric coatings extraction | food-type dependent cell conditions |
| ASTM D3359 | Cross-hatch tape pull | class 5B |
| ASTM D2578 | Dyne solution wetting | 42–46 mN/m |
| ASTM F88 | Lamination bond strength | 2.5–4.0 N/15 mm |
| EU Directive 94/62/EC | Packaging heavy metals | Pb, Cd, Hg, Cr VI sum 100 mg/kg |
Under atmospheric application on degreased cold-rolled steel, a single-pack wash primer based on S-LEC BX-1 produces a 5–12 μm dry film that passivates the metal surface and provides a polar anchor for epoxy or polyurethane topcoats. The formulation consists of 7–10 wt% S-LEC BX-1 dissolved in 80:20 isopropanol:methyl ethyl ketone, 2–4 wt% phosphoric acid as 85% aqueous solution, 1.5–3.0 wt% zinc phosphate, and 0.2–0.5 wt% polysiloxane defoamer. Pot life at 20°C is 24–48 h; storage must be in stainless steel or polypropylene because carbon steel containers complex with phosphoric acid and darken the binder. Application by conventional air spray at 0.25–0.35 MPa pot pressure and 0.15–0.25 MPa air cap pressure gives a wet film thickness of 15–25 μm, drying to 5–8 μm at 15–18°C in 15–20 min. Cross-cut adhesion on blast-cleaned Sa 2.5 steel per ISO 2409 is class 1 after 48 h; pull-off adhesion per ISO 4624 with a 20 mm dolly typically records 4–6 MPa, with cohesive failure in the epoxy topcoat rather than interfacial delamination. Film thickness above 10 μm is forbidden because the acidic PVB layer becomes hygroscopic and produces blistering in high-humidity coastal exposure; application below 3 μm leaves exposed steel edges that initiate creepage. The primer is incompatible with zinc-rich silicate topcoats because residual phosphate acidity can hydrolyze the silicate binder; a barrier coat is required before overcoating.
For 0.38 mm PVB interlayer film compounded from S-LEC BX-1 with 20–30 phr triethylene glycol bis(2-ethylhexanoate), the extruder must deliver sufficient shear to homogenize plasticizer without creating gel particles that later act as optical defects. A co-rotating twin-screw extruder with 44:1 L/D, 25–28 mm screw diameter, and segmented kneading blocks is run at 160–190°C barrel profile and 200–250 rpm screw speed. The flat-film die with 1.0–1.2 mm lip gap is maintained at 185–200°C, and the melt is cast onto a polished chill roll at 15–25°C with 15–25 m/min haul-off. Moisture before lamination is equilibrated to 0.4–0.6 wt% at 20°C and 25% RH; moisture above 0.65 wt% generates autoclave bubbles, while below 0.3 wt% adhesion becomes too low. Lamination cycle under an oil-water autoclave of 1.0–1.3 MPa pressure and 130–140°C for 2–4 h completes adhesion. The pummel adhesion value, although not an ISO method, is controlled to 3–7 on the conventional 0–10 scale; automotive windshields typically use 6–7, while architectural safety glazing uses 3–4. Haze measured per ASTM D1003 remains below 0.8% after autoclave. Plasticizer selection influences washout in isopropanol; test coupons extracted in isopropanol at 60°C for 16 h should retain at least 90% of original light transmittance to avoid field delamination near glass edges.
During bead-mill dispersion of cobalt-modified acicular iron oxide for magnetic tape, S-LEC BX-1 is combined with a polyester-urethane binder at a total binder loading of 16–20 phr per 100 phr magnetic pigment. The PVB hydroxy groups adsorb onto the pigment surface, reducing millbase thixotropy; Brookfield pseudoplastic index at 2 rpm/20 rpm is maintained below 2.5 during 45–60 min residence in a horizontal bead mill with 0.3–0.5 mm zirconia beads and 8–10 m/s tip speed. A typical letdown consists of cyclohexanone and methyl ethyl ketone at 70:30, carbon black 2–4 phr, alumina 3–5 phr, and a fatty-acid dispersant 1.5–2.5 phr. Final dispersion is filtered through 0.5 μm depth filters and coated onto 6–12 μm PET at 20–40 m/min; magnetic orientation is applied with 2,000–3,000 G before the coating enters a 70–90°C drying arch. Calendering between 80–100°C hardened steel rolls at 100–150 kgf/cm line pressure compacts wet coating from 4–6 μm to 2–4 μm dry tape. Published data for this specific configuration is limited; process transfers between PVB grades require revalidation of dispersion residence time because molecular weight differences shift the pigment wetting equilibrium and can elevate filtration pressure on commercial coaters.
Thermal transfer ribbon donor layers built with S-LEC BX-1 and carnauba wax are coated from methyl ethyl ketone–toluene at 20–30 wt% solids. The PVB content is held between 10 and 14 wt% of dry coating, with pigment loading 8–12 wt% for black resin-based ribbons. Phase separation between wax and PVB during solvent evaporation controls the fracture path under printhead temperature; a differential scanning calorimetry melting endotherm at 70–80°C for the wax phase and a PVB glass transition at 58–65°C create a two-phase donor layer that transfers cleanly at 90–110°C printhead pulsing. Back-coat silicone slip layer is applied at 0.2–0.4 μm; donor layer thickness is 2–4 μm. Coating speeds on gravure lines are 100–200 m/min with drying temperatures 50–80°C. Printhead energy 0.20–0.35 mJ/dot for 300 dpi heads is typical; high PVB above 14 wt% increases thermal smear resistance but reduces transfer density below 1.0 OD measured by reflection densitometer. In barcode applications, edge sharpness is assessed with ISO/IEC 15415, requiring minimum symbol contrast 80% and grade B or better. The same donor layer may be coated on 3.5–4.5 μm PET base without anti-static back-coat in short-run industrial label systems, but substrate tension must remain below 80 N/m to prevent blocking and ribbon telescoping on rewind.
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Polyvinyl butyral resin grade S-LEC BX-1 is supplied by Sekisui Chemical Co., Ltd. as a white, free-flowing powder derived from the acetalization of polyvinyl alcohol with n-butyraldehyde. The grade belongs to the S-LEC B resin series, within which the BX designation identifies a higher molecular weight profile than the BM and BL series. This powder resin is distinct from S-LEC interlayer film grades used in laminated glass, although both are PVB chemistries. The polymer backbone carries three repeat-unit types—vinyl butyral, vinyl alcohol, and vinyl acetate—whose relative proportions control solubility, adhesion, and thermal decomposition. Published lot certifications for S-LEC BX-1 generally report residual polyvinyl alcohol content in the range of 19.0–23.0 mol% when determined by ASTM D1396-20, with volatile matter not exceeding 1.0 wt% and ash not exceeding 0.05 wt%. The powder dissolves readily in mixtures of polar and nonpolar solvents, but not in pure aliphatic hydrocarbons. Because the resin is used as a thermoplastic binder rather than a cured matrix, its rheological and thermal behavior must be matched to the solvent system and the inorganic solid loading of each application.
The receiving-inspection matrix applied to S-LEC BX-1 powder prior to compounding is summarized below.
| Property | Test method | Typical acceptance range |
|---|---|---|
| Residual polyvinyl alcohol content | ASTM D1396-20 | 19.0–23.0 mol% |
| Volatile matter | ISO 3251:2019 | ≤1.0 wt% |
| Ash content | ISO 3451-1:2019 | ≤0.05 wt% |
| Solution viscosity, 10 wt% in ethanol/toluene (1:1 w/w) at 20 °C | DIN 53015:2019 | 200–400 mPa·s |
| Glass transition temperature, DSC, 10 °C/min under nitrogen | ISO 11357-2:2020 | 72–78 °C |
In tape-casting operations, the selection of S-LEC BX-1 as the thermoplastic binder phase is driven primarily by binder burnout, green tape tensile strength, and slurry stability. A typical non-aqueous tape-cast formulation contains the PVB binder at 4–8 wt% of total slurry mass, with plasticizer such as benzyl butyl phthalate or dioctyl phthalate added at 10–30 phr relative to binder, and a solvent blend of methyl ethyl ketone, toluene, and ethanol. On a production doctor blade caster equipped with a 0.3–0.8 mm gap and a carrier speed of 0.5–2.0 m/min, the slurry is adjusted to a viscosity of 1.5–4.0 Pa·s at 10 s⁻¹ and 25 °C. The shear history matters: a high-shear dissolver with tip speed of 5–12 m/s is used only for pigment deagglomeration, while subsequent low-speed mixing prevents chain scission. The cast tape is dried at 40–80 °C until residual solvent is below 1 wt%, as measured by an isothermal thermogravimetric hold. High residual solvent in tapes above 0.4 mm produces surface skinning and entrapped bubbles. Binder selection therefore determines drying kinetics, with higher molecular weight grades such as S-LEC BX-1 extending drying time but increasing tensile strength of the green tape.
The hydroxyl functional density in S-LEC BX-1 is the primary molecular parameter controlling hydrogen-bonding interactions with polar solvents and ceramic oxide surfaces. In ethanol/toluene systems, an increase in residual hydroxyl content raises the effective coil volume and low-shear viscosity at the same nominal solids. The solubility window narrows outside the 40:60 to 60:40 weight ratio of ethanol to toluene; above 70 wt% toluene, the solution becomes turbid, while above 80 wt% ethanol, chain aggregation can create viscous gels at room temperature. The dissolution procedure on a production vessel is therefore sequenced: the powder is sifted into the ethanol-rich phase under agitation at 500–800 rpm, followed by toluene addition over 20–30 min to avoid shock precipitation. The resulting binder vehicle is held for 12–24 h at 20–25 °C to allow full solvation. Filtration through 20–50 μm mesh removes undispersed agglomerates. In ceramic slurries, the same hydroxyl groups compete with dispersants for adsorption sites on barium titanate or alumina surfaces. A fatty acid dispersant with an acid value above 50 mg KOH/g can destabilize the slurry because acid-mediated acetal hydrolysis reduces molecular weight over time. Formulators therefore maintain the slurry above pH 4.5 and avoid prolonged residence above 40 °C.
When S-LEC BX-1 is dissolved at 10 wt% solids in an ethanol/toluene (1:1 w/w) mixture at 20 °C, the resulting solution viscosity is typically reported between 200 and 400 mPa·s as a function of lot-to-lot hydroxyl variation. This viscosity is higher than a low-viscosity printing resin such as S-LEC BM-2. In thick-film printing paste manufacture, the binder is combined with silver flake or silver-coated copper particles on a planetary mixer followed by a triple-roll mill; the roll gaps are set to 25–75 μm for primary dispersion and 5–15 μm for final fineness. Binder demand increases with the specific surface area of the metal. S-LEC BX-1 is selected when screen printing on low-temperature co-fired ceramic green sheets requires paste with yield stress between 50 and 150 Pa and final viscosity between 15 and 40 Pa·s at 10 s⁻¹. Because the high-molecular-weight PVB chain resists shear thinning less than ethyl cellulose at equal solids, the paste retains line height after screen release but can exhibit tailing if the solvent evaporation rate exceeds 0.02 mg/m²·s during ambient settling. This processing boundary is managed by adding 2–5 wt% of a slow-evaporating dibasic ester or terpineol to the vehicle.
The substitution of a thermoplastic PVB binder such as S-LEC BX-1 for ethyl cellulose in high-solids conductor pastes changes the solvent release profile and burnout onset. Ethyl cellulose depolymerizes between 300 and 400 °C; S-LEC BX-1 begins side-group elimination near 200 °C and completes oxidative removal between 400 and 500 °C in air. This difference permits a shorter burnout plateau before metallization in co-fired multilayer ceramic substrates, but requires a more gradual heating ramp of 0.5–2 °C/min from 150 to 350 °C to avoid trapped volatiles. The binder difference also alters binder demand and thixotropy. Formulations containing S-LEC BX-1 at 3–6 wt% of total paste mass produce a pseudoplastic flow curve with shear thinning index of 0.6–0.8 measured between 1 and 100 s⁻¹, compared with 0.5–0.7 for a comparable ethyl cellulose vehicle. Screen mesh selection shifts accordingly: 325 mesh screens require a lower solids content to avoid clogging, while 200–250 mesh screens tolerate the higher elasticity of the PVB vehicle. No uniform formulation rule exists; published data for this specific substitution in an S-LEC BX-1/silver paste configuration is limited, and pilot-scale print trials are required to adjust leveling time and edge definition.
Thermal decomposition of polyvinyl butyral proceeds in two distinct mass-loss events under air. The first mass loss above 200 °C is dominated by elimination of butyraldehyde and water from the acetal rings; the second between 350 and 500 °C is oxidative chain scission and combustion of the remaining carbon skeleton. S-LEC BX-1 is not suitable for low-temperature firing below 450 °C if residual carbon below 0.1 wt% is required in the fired ceramic. For barium titanate multilayer devices, binder burnout is conducted in a forced-air conveyor furnace with a 3–6 h total residence time above 250 °C. Rapid heating beyond 5 °C/min between 250 and 350 °C produces internal pressure from volatile evolution, resulting in delamination or pinhole defects. Control of oxygen partial pressure is also critical: oxygen-depleted zones below 10 vol% O₂ leave carbonaceous residue that shifts from amorphous carbon to difficult-to-remove graphitic domains. Thermogravimetric analysis per ISO 11358-1:2022 at 10 °C/min in air is used as the incoming lot comparative test, not as a direct production forecast.
Storage of S-LEC BX-1 at ambient temperature below 30 °C and below 60 % RH preserves free-flowing powder character. Prolonged exposure above 60 % RH increases moisture content above 1.5 wt%, which causes clumping during solvent addition and uneven solvation. Pre-drying in a dehumidified oven at 55–60 °C for 2 h is applied when incoming moisture exceeds 1.0 wt%. The resin should not be stored in proximity to amines, strong acids, or oxidizing agents; ammonia vapor can catalyze acetal hydrolysis and reduce the molecular weight of surface powder. These incompatibilities are relevant to mixed-chamber chemical storage in production warehouses.
