| HS Code | 571891 |
| Product Name | MOWITAL BA 20 S |
| Chemical Name | Polyvinyl Butyral (PVB) |
| Cas Number | 63148-65-2 |
| Appearance | White fine powder |
| Density | 1.1 g/cm³ |
| Bulk Density | 0.78 g/cm³ |
| Glass Transition Temperature | 68 °C |
| Hydroxyl Content | 20 % |
| Butyral Content | 78 % |
| Acetate Content | 2 % |
| Viscosity | 20 mPa·s |
| Solubility | Soluble in alcohols and esters; insoluble in water |
As an accredited Mowital BA 20 S factory, we enforce strict quality protocols—every batch undergoes rigorous testing to ensure consistent efficacy and safety standards.
| Packing | Mowital BA 20 S is supplied as a free-flowing powder in 20 kg multi-walled paper bags. |
| Container Loading (20′ FCL) | Mowital BA 20 S loaded as 20′ FCL in sealed, secured packaging, ensuring safe transport and stability. |
| Shipping | Mowital BA 20 S (polyvinyl butyral resin) is a non-hazardous, non-regulated material for transport. Ship in sealed, moisture-proof bags or containers, protected from heat and humidity. Avoid dust exposure; keep dry and ventilated. Standard dry freight, truck, or container shipment is suitable. |
| Storage | Store Mowital BA 20 S in a cool, dry, well-ventilated area, away from heat, sparks, and direct sunlight. Keep the container tightly sealed to protect against moisture absorption and contamination. Avoid storage near oxidizers or ignition sources. Ideal temperature range is below 30°C. With proper storage, shelf life can be maintained for several years. |
| Shelf Life | Mowital BA 20 S shelf life is approximately 2 years when kept in original unopened packaging, cool and dry. |
In etch-primer production, Mowital BA 20 S functions as the film-forming colloid that suspends acid-stable corrosion inhibitors before spray application. The raw material is dissolved to 30–35 wt% in an ethanol/1-butanol mixture at 55:45 by weight under low-shear agitation of 800–1,200 rpm; the solution is then cooled to 20–25 °C before addition of phosphoric acid at 1.0–1.6 wt% of total primer and zinc phosphate at 5.0–7.0 wt%. Mowital BA 20 S is charged at 6.0–8.5 wt% of total liquid wash primer, with higher loadings above 9 wt% producing a viscosity increase that narrows spray atomisation at standard 1.4–1.8 mm nozzle orifices. After acid addition, the hydrolytic degradation of polyvinyl acetal bonds makes batch pot life 24–48 h; viscosity drift measured as a rise of 10–15 s on a DIN 4 mm cup indicates disposal. Filtration through a 25 µm bag and airless spray application at 15–25 °C and 30–60 % RH produce a dry film thickness of 8–12 µm. Adhesion is assessed according to ASTM D3359-17 Method B on grit-blasted steel, with ISO 4624:2016 pull-off values typically falling between 4.0 and 6.0 MPa when a two-pack polyurethane topcoat is applied within 4–8 h. The system is specified under ISO 12944-5:2019 for atmospheric corrosion protection, and raw-material compliance includes REACH registration and absence of Substances of Very High Concern, while final-coating metallic parts must respect RoHS 2011/65/EU limits for lead, cadmium, and chromium compounds. This primer is not suitable for continuous immersion or for aluminium substrates that already carry a chromate conversion layer with pH below 3.5; in such cases, selective blushing and intercoat delamination appear within 72 h of humidity exposure.
| Standard / clause | Test or scope | Acceptance target |
|---|---|---|
| ASTM D3359-17 Method B | Cross-cut adhesion on grit-blasted steel | Classification 4B or better |
| ISO 4624:2016 | Pull-off adhesion before overcoat window | 4.0–6.0 MPa with cohesive failure permitted |
| ISO 1519:2011 | Conical mandrel bend crack resistance | No visible cracking at 5 mm diameter |
| ISO 2811-1:2016 | Liquid primer density | 0.95–1.05 g/cm³ |
| RoHS 2011/65/EU | Restricted metal content in final coated article | Lead < 1,000 ppm, cadmium < 100 ppm |
Ceramic tape casting lines processing submicrometer barium titanate powders use Mowital BA 20 S as the primary organic matrix when producing thin dielectric sheets for multilayer capacitors. The binder is prepared by dissolving 8–12 wt% relative to ceramic powder mass in a toluene/ethanol solvent blend at 60:40 by weight, with 4–6 wt% of butyl benzyl phthalate as plasticiser and 0.5–1.2 wt% of a phosphate ester dispersant. Slurry mixing proceeds in a 50 L ball mill charged with 3 mm yttria-stabilised zirconia media at 60–65 rpm for 18–24 h, followed by vacuum de-airing at 10–30 kPa until dissolved gas content falls below 0.5 vol%. Tape is cast through a doctor blade gap of 250–400 µm onto silicone-coated polyester carrier at 0.6–1.2 m/min; three-zone drying at 60–80 °C reduces residual solvent to 1–3 wt% before release. Binder burnout during sintering from 350–450 °C at 0.5 °C/min is controlled by the low inorganic ash specification of the grade; residual ash above 0.05 wt% shifts dielectric loss and can reduce insulation resistance after co-firing with nickel internal electrodes. The cast green sheets are cut, screen-printed with nickel internal electrode paste, and laminated into multilayer capacitor bodies with dielectric thickness of 1.0–2.5 µm, low-temperature co-fired ceramic substrates, and alumina chip carriers. The final dielectric layers in X7R multilayer ceramic capacitors are classified under IEC 60384-22:2019, while the sintered component must meet RoHS 2011/65/EU exemptions applicable to barium titanate dielectrics. Mowital BA 20 S is limited to non-aqueous slurry systems because water uptake above 0.3 wt% raises slip viscosity by 20–30 % and causes pinhole defects in tapes thinner than 40 µm.
Reverse gravure and flexographic inks formulated with Mowital BA 20 S exhibit a viscosity ceiling directly tied to binder molecular weight and oxygenated solvent compatibility. In ethyl acetate/ethanol blends at 80:20, Mowital BA 20 S is charged at 4–8 wt% of finished ink; addition beyond 10 wt% raises efflux time above 25 s on a DIN 4 mm cup at 23 °C and creates spitting and fogging on flexographic presses running at 180–250 m/min. Pigment dispersion uses a high-speed dissolver at 3,000 rpm followed by a bead mill with 1.2–1.4 mm zirconia beads until grind gauge fineness reaches 5–10 µm. The binder is post-added during letdown at 15–25 °C to avoid heat-induced acetal oxidation. On corona-treated BOPP with surface tension 38–42 mN/m, the ink dries in 55–70 °C high-velocity dryers with residual solvent below 5 mg/m². Suitability for food-contact printed packaging is assessed under 21 CFR 175.105 for indirect food-contact components, Regulation (EC) No 1935/2004 for overall migration, and EU 10/2011 specific migration limits where the printed film is separated from food by a functional barrier. Terminal printed materials include snack food pouches, BOPP labels, and PVC shrink sleeves. Mowital BA 20 S should not be used as the sole binder in retortable pouch inks or on low-density polyethylene without corona treatment because heat sterilisation above 121 °C causes cohesive failure within the ink film.
Aluminium lidding foil passed through a reverse gravure coating unit at 80–120 m/min receives Mowital BA 20 S as a heat-seal resin in solvent-based lacquer before lamination to APET or PVC trays. The resin is charged at 12–18 wt% of dry lacquer, with total coating solids held at 20–25 % in an ethyl acetate/isopropanol blend and a plasticiser level of 3–6 wt% on dry resin to bring the seal initiation temperature below 95 °C. Coating weight is maintained at 2.5–4.5 g/m² dry film; below 2.0 g/m², void formation at tray flange radii produces peel strength below 6 N/15 mm. Heat sealing against APET or PVC is performed at 130–150 °C platen temperature, 0.25–0.45 MPa pressure, and 0.8–1.5 s dwell. Compliance for food contact includes EU 10/2011 overall migration testing at 10 mg/dm² and 21 CFR 175.300 for resinous and polymeric coatings; pharmaceutical lidding requires additional batch extractables data aligned with USP <661.1> for containers. Terminal products include dairy portion lids, coffee capsule membrane lids, and pharmaceutical blister lidding foil. Above 6 wt% plasticiser, seal strength at 85 °C improves but blocking between coated foil surfaces in roll storage becomes unrecoverable; unwind tension above 15 N/m at 35 °C warehouse conditions should be avoided.
Formulation of a single-component wood primer around Mowital BA 20 S begins with dissolution in an ethanol/ethyl acetate blend at 80:20 by weight at 30–40 °C, followed by the addition of 8–12 wt% of the formulation as PVB solids and 2–4 wt% of a phthalate-free plasticiser on solid resin. The primer is applied by HVLP spray at 2–3 bar as a wet film of 80–120 µm; at 20 °C the alcohol-rich solvent system flashes off within 10–15 min, allowing sanding with P240 paper after 60 min. Tannin blocking is assessed by applying a white polyurethane topcoat and measuring colour change as a Δb value below 1.5 after 24 h at 40 °C and 85 % RH according to ISO 7724-3:1984; Mowital BA 20 S reduces tannin migration from oak and meranti veneers compared with nitrocellulose primers at equivalent film thickness. Surface adhesion follows ASTM D3359-17 Method B, while resistance to wet rub is evaluated according to EN 927-2:2016 for coating systems on exterior wood. Formulation VOC content must satisfy Directive 2010/75/EU solvent emission limits for wood coating activities. Terminal products include interior furniture fronts, door skins, and profiled oak veneers, but the primer is not intended for horizontal exterior surfaces with standing water exposure or for two-component acid-catalysed topcoats where residual PVB films delay crosslinking and reduce block resistance.
Extruded polymethyl methacrylate sheet entering CNC routing and laser cutting is protected by a peelable PVB film formulated with Mowital BA 20 S at 10–15 wt% of total solution. The coating is deposited by air-assisted spray or flow coating to a dry film thickness of 30–50 µm; drying occurs at 20–25 °C for 20–30 min or in a 45 °C convection tunnel for 5–8 min. Peel removal force on PMMA is maintained between 0.2 and 0.8 N/25 mm, avoiding residue at the film edge. The dried film protects against abrasive contact and laser cutting debris, and can be removed without alcohol cleaning. Compliance for industrial handling includes REACH registration and the absence of Substances of Very High Concern, while final coated articles intended for indoor consumer use are assessed for heavy metals according to EN 71-3:2019+A1:2021 migration limits only when toy contact is foreseen. Terminal types include laser-cut acrylic signage, prototype light guides, and sanitaryware protection during transit. The formulation is limited to non-porous surfaces; on polycarbonate, stress cracking may occur if the solvent system contains more than 5 wt% ketones, so etch testing under ASTM D543 is required before application.
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Mowital BA 20 S is a thermoplastic polyvinyl butyral (PVB) resin supplied as a white free-flowing powder. Manufacturer documentation for the grade lists a nominal dynamic viscosity of 18–22 mPa·s measured as a 10 wt% solution in ethanol at 20 °C in accordance with DIN 53015. The polyvinyl alcohol content is specified as 18–21 wt%, residual vinyl acetate is controlled to ≤3 wt%, and ash content is controlled to ≤0.1 wt% by ISO 3451-1. The glass transition temperature is reported as 66–70 °C by differential scanning calorimetry according to ISO 11357-2:2020. The grade is used in solvent-borne metal primers, flexographic and gravure ink concentrates, ceramic green-sheet binders, and heat-curable laminating adhesives. The 20 designation denotes the solution-viscosity class; the S suffix identifies the standard powder form. In comparison with higher-viscosity Mowital grades, BA 20 S permits higher non-volatile solids at equivalent application viscosity. In comparison with lower-viscosity Mowital B 14 S, films of BA 20 S form with higher cohesive strength after solvent evaporation. Published comparative data for the BA modification relative to the standard B 20 H designation is limited; batch-specific acetalization and hydroxyl values should be verified against the manufacturer’s certificate of analysis.
The powder dissolves in lower alcohols, ketones, esters, and glycol ethers; it is not soluble in water or aliphatic hydrocarbons. Powder exposed to relative humidity above 60 % may require pre-drying before dissolution, because absorbed water increases hydrogen bonding and delays true solution formation. Storage at ≤25 °C and ≤60 % relative humidity is recommended to prevent blocking.
For high-shear flexographic ink concentrates, the limiting variables are binder solution viscosity, solubility in fast mid-boiling solvent blends, and pigment wetting on corona-treated polyethylene and oriented polypropylene films. The viscosity of BA 20 S in ethanol is measured by falling-ball viscometry according to DIN 53015; rotational viscometry according to ISO 3219 is used to define the high-shear portion of the flow curve. In ethanol/ethyl acetate blends, solution solids can be increased until the mill-base viscosity under shear exceeds the feed limits of the bead mill. High-viscosity grades such as Mowital B 30 H and B 60 H reduce the acceptable solids level at equivalent pigment loading.
Production-scale masterbatches are dispersed on vacuum dissolvers with scraped-wall agitators, then milled in bead mills with zirconium oxide grinding media of 0.8–1.2 mm diameter. Final fineness of grind is evaluated with a Hegman gauge in accordance with ISO 1524, with target values of 5–15 µm for flexible packaging inks. Dissolution of BA 20 S in alcohol-rich solvent blends is carried out below 50 °C; higher temperatures accelerate solvent loss and can produce micro-gel residues on the vessel wall.
In gravure ink applications, the lower solution viscosity allows a higher binder-to-pigment ratio without exceeding press viscosity limits. Solvent release during high-speed printing is influenced by the resin’s hydroxyl content; retained solvent in the dried ink film is measured by gas chromatography in accordance with ISO 15181. For overprint varnishes, BA 20 S is blended with nitrocellulose or ketone resins; compatibility is confirmed by film clarity and haze measurement under ISO 14782. The grade exhibits limited tolerance for aromatic or aliphatic hydrocarbon diluents, and a polar oxygenated solvent fraction must remain the major component of the solvent blend.
In tape casting, the binder is removed during debinding after the green sheet has been cast onto a silicone-coated carrier. Residual ash from the binder directly influences sintered dielectric performance. Because BA 20 S is specified at ≤0.1 wt% ash by ISO 3451-1, it is used in aluminium oxide and barium titanate green sheets where alkali and alkaline earth residues must be minimized. Slurry preparation is carried out in planetary mixers or bead mills; viscosity is measured at 20 °C by rotational rheometry according to DIN 53019. For ceramic powders with an average particle size of 0.5–2.0 µm, mill-base viscosity is typically adjusted to 1.5–4.0 Pa·s at 10 s⁻¹; the target depends on casting speed, blade gap, and carrier speed.
Deaeration of tape-casting slurries is performed under vacuum at 0.2–0.5 kPa absolute pressure for 10–30 min; residual air bubbles larger than 50 µm cause pinholes in green sheets. Binder loading above 15 wt% relative to ceramic powder can cause slumping during debinding because the PVB softens before decomposition. Binder burn-out is performed in air between 350 °C and 450 °C; the low ash and controlled residual acetate content reduce carbon residues and pinhole defects. Thermogravimetric analysis under ISO 11358-1 at 5 K/min is used to establish the onset of thermal decomposition and to design the debinding plateau. Deagglomeration should remain below 40 °C to avoid solvent loss and skin formation in the slurry. Incoming quality control for critical dielectric applications includes viscosity, ash content, and moisture determination because batch-to-batch variation in hydroxyl content can shift the burn-out profile.
For wash primers applied to aluminium and cold-rolled steel, the PVB resin functions as the film-forming carrier for phosphoric acid and zinc phosphate or zinc chromate pigments. The hydroxyl groups of BA 20 S participate in hydrogen bonding with metal oxide and phosphate layers. Adhesion is evaluated on degreased substrates by cross-cut testing according to ISO 2409 and pull-off testing according to ISO 4624. Typical primer formulations contain 5–10 wt% PVB solids in an alcohol/toluene or alcohol/ketone solvent mixture, with phosphoric acid added at 0.5–2.0 wt% of total formulation. The acid must be introduced as a diluted acid solution under controlled agitation; direct addition can precipitate the PVB or generate localized hydrolysis.
Compatibility with amine-based additives is limited. Primary or secondary amines raise the pH and may destabilize the acid-pretreatment balance. Qualification of wash primers based on BA 20 S should include salt-spray exposure according to ISO 9227 and humidity resistance according to ISO 6270-2. Published data for this specific grade in amine-free wash primers is limited; formulations should be validated at the full production paint batch size. The processing window for acid addition is narrow; acid solution concentration, addition rate, and batch temperature below 25 °C must be controlled to avoid viscosity fluctuation and partial precipitation.
When BA 20 S replaces B 30 H in structural adhesive films, the lower molecular weight of the 20 mPa·s grade lowers film tensile strength but improves substrate wetting at lower lamination temperatures. The difference is most visible in dynamic mechanical analysis of plasticized films: the storage modulus in the rubbery plateau decreases as plasticizer content exceeds 20 phr. Laminating adhesives based on BA 20 S are processed at similar nip temperatures but allow coating weights of 3–6 g/m² on corona-treated polyester and aluminium foil. Users must verify peel adhesion after ageing according to ISO 11339, because lower cohesive strength can shift failure mode from cohesive to adhesive at elevated plasticizer levels. Published data for this specific substitution is limited; the manufacturer’s data should be used to compare acetalization degree, residual hydroxyl content, and molecular weight.
The table compares the solution viscosity and typical application range of BA 20 S with two higher-viscosity PVB grades. The values are manufacturer-reported for standard powder forms and are not batch-specific.
| Grade | Nominal viscosity as 10 wt% solution in ethanol at 20 °C | Polyvinyl alcohol content | Ash content | Typical application |
|---|---|---|---|---|
| Mowital BA 20 S | 18–22 mPa·s | 18–21 wt% | ≤0.1 wt% | Metal primers, inks, ceramic binders |
| Mowital B 30 H | 28–34 mPa·s | 18–21 wt% | ≤0.1 wt% | Ceramic binders, high-mechanical films |
| Mowital B 60 H | 55–65 mPa·s | 18–21 wt% | ≤0.1 wt% | Laminating adhesives, overprint varnishes |
Regulatory documentation for the product is obtained from the manufacturer’s REACH dossier. The resin is not formulated with substances of very high concern above the 0.1 wt% reporting threshold. In the EU, RoHS Directive 2011/65/EU compliance for finished electrical or electronic articles depends on the formulator’s raw-material and phthalate screening; the base PVB resin alone does not establish article-level compliance. For food-contact printing inks and coatings, migration testing under Regulation (EU) No 10/2011 or applicable national legislation is required because the base resin alone does not confer food-contact approval. If use in food-contact adhesives is intended, the finished adhesive must be evaluated under 21 CFR 175.105 or 21 CFR 176.170 as appropriate.
