| HS Code | 497987 |
| Product Name | Mowital G 13 |
| Chemical Family | Polyvinyl butyral (PVB) |
| Appearance | White to pale yellow powder |
| Molecular Weight | Approximately 13,000 g/mol |
| Glass Transition Temperature | Approximately 60°C |
| Density | Approximately 1.1 g/cm³ at 20°C |
| Butyral Content | Approximately 70–80 wt% |
| Hydroxyl Content | Approximately 18–22 wt% |
| Acetate Content | Approximately 1–3 wt% |
| Viscosity | Low viscosity; 5% solution in ethanol approximately 13 mPa·s at 20°C |
| Softening Point | Approximately 85–95°C |
| Tensile Strength | Approximately 50 MPa |
| Elongation At Break | Approximately 60% |
| Solubility | Soluble in alcohols, ketones, and esters; insoluble in water |
As an accredited Mowital G 13 factory, we enforce strict quality protocols—every batch undergoes rigorous testing to ensure consistent efficacy and safety standards.
| Packing | Mowital G 13 is supplied as free-flowing granules in 25 kg multi-layer paper bags with an inner polyethylene liner. |
| Container Loading (20′ FCL) | Mowital G 13 loaded in 20′ FCL, palletized, securely braced, protected from moisture, with proper hazard labeling and ventilation. |
| Shipping | Mowital G 13 is a polyvinyl butyral resin supplied as a free-flowing granular solid. It is not classified as dangerous goods for transport, so no UN number or hazmat documentation is required. Ship in sealed moisture-proof bags on pallets, protected from humidity, heat, and direct sunlight. |
| Storage | Store Mowital G 13 in a cool, dry, well-ventilated area away from direct sunlight, heat, and ignition sources. Keep the original container tightly closed to prevent moisture absorption and contamination. Avoid contact with strong oxidizers. Follow safe handling procedures and observe the labeled shelf life to maintain product quality. |
| Shelf Life | Mowital G 13 has a shelf life of approximately 2 years when stored in its original sealed packaging under cool, dry conditions. |
Flexographic and gravure ink systems on corona-treated polyethylene and metallized polyester use Mowital G 13 as a low-viscosity polyvinyl butyral binder. The nominal 10 wt% ethanol solution viscosity of 13 mPa·s at 20°C under DIN 53015 permits an increase in total solids of 2–4 wt% relative to medium-viscosity PVB grades at the same press-ready flow time. In an 80:20 ethanol/ethyl acetate starting solvent blend, a clear overprint containing 12 wt% Mowital G 13 typically shows a flow time of 18–25 s in a 4 mm cup under ISO 2431:2019. Pigment/binder ratios between 2:1 and 3:1 are used for process colors and white inks on flexible packaging. The resin solution is prepared as a pre-dissolved cut and added before pigment grind under high-shear dispersion to avoid viscosity hysteresis and seed formation. On low-dyne polyethylene film with surface tension of 38–40 mN/m, the hydroxyl functionality of Mowital G 13 improves anchorage when combined with nitrocellulose or polyurethane, and laminated structures are tested for bond strength by ASTM F904 or ASTM F88/F88M-23. Ethanol content in lamination inks should remain below 60 wt% of total solvent because PVB releases alcohol more slowly than ketone or ester solvents, and retained-solvent defects become measurable at press speeds above 150 m/min. Aromatic hydrocarbon dilution should not exceed 20 wt% of total solvent unless a glycol ether coupling solvent is included. Mowital G 13 is suitable for foil-based confectionery inks and overprint varnishes, but it is not a standalone barrier binder for retort-grade laminations; nitrocellulose, epoxy, or polyurethane synergists are required for autoclavable structures. Resin stored at relative humidity above 60% should be dried at 60°C for 4 h before dissolution to prevent haze and solution viscosity drift.
In a single-pack phosphoric acid-activated wash primer based on Mowital G 13, the binder solution is prepared at 7–9 wt% solids in an 85:15 isopropanol/butanol mixture. Phosphoric acid at 85% concentration is charged at 2–4 phr on resin solids, and zinc phosphate or zinc tetroxychromate is dispersed at 20–30 wt% of total solids. Acid must be diluted in the alcohol phase and added to the PVB solution under continuous high-shear agitation at 15–20°C; reverse addition or localized contact with concentrated acid drives pH below 2.0, causing acetal hydrolysis and rapid viscosity loss. A correctly letdown wash primer at 20°C has a practical pot life of 6–10 h. The primer is applied at 5–10 μm dry film thickness to degreased steel or aluminum and dried for 30–60 min before overcoating. Adhesion is verified by cross-cut testing to ISO 2409:2020 and pull-off testing to ISO 4624:2016; on cold-rolled steel blasted to Sa 2½, pull-off values above 5 MPa are typical at 8 μm dry film thickness. Commercial PVB grades of this type contain residual polyvinyl alcohol functionality in the range of 12–20 wt%, and the certificate value for Mowital G 13 determines wetting and acid tolerance. The primer must not be combined with amine-based additives because amines neutralize phosphoric acid and collapse adhesion to the metal surface. When chromate pigments are replaced with zinc phosphate, salt-spray resistance tested to ASTM B117-19 is typically shorter, and a barrier topcoat should be applied within 24 h to prevent flash rusting on bare steel.
Tape casting of barium titanate-based dielectric layers for multilayer ceramic capacitors uses Mowital G 13 as a low-ash organic binder in non-aqueous systems. The ceramic powder is first milled in a toluene/ethanol 60:40 solvent mixture with a polycarboxylate dispersant at 0.5–1.5 wt% of powder mass. Mowital G 13 is then added at 4–8 wt% of ceramic solids together with butyl benzyl phthalate or dioctyl phthalate at 20–30 phr on binder solids. Slurry viscosity is adjusted to 1,000–3,000 mPa·s at 10 s⁻¹ for doctor-blade casting. Green tape thickness is typically 2–5 μm for high-capacitance MLCC and up to 150 μm for LTCC substrates. The plasticized green tape after Mowital G 13 addition shows elongation at break of 8–15% at 23°C and 50% RH, which allows slitting and screen printing without edge cracking. The critical process window is debinding: a ramp of 0.5–1.0°C/min through 150–250°C prevents blistering, while primary PVB decomposition occurs between 250°C and 450°C in air or nitrogen. Sintering cycles for X7R barium titanate formulations generally require a hold at 550°C for 2 h to oxidize residual carbon; residual carbon above 0.05 wt% can lower insulation resistance and shift dielectric loss. Thermogravimetric verification is carried out to ASTM E1131-20. Published quantitative dielectric loss data for Mowital G 13 in a specific X7R formulation is limited and must be validated against capacitor manufacturer electrode compatibility. For LTCC glass-ceramic tapes, free hydroxyl groups in the PVB can interact with borosilicate glass frit and shift sintering onset by 10–20°C; a high-boiling plasticizer such as dibutyl phthalate reduces this sensitivity. Lamination is typically conducted at 20–30 MPa and 60–70°C to achieve green density before burnout.
On 20–30 μm aluminium foil lidding, Mowital G 13 is formulated into a heat-sealable coating at 15–20 wt% solids in ethanol/ethyl acetate, with acetyl tributyl citrate at 10–20 phr on binder solids and erucamide slip additive at 0.5–2 wt% of total solids. Dry coat weight is maintained at 1.5–3.0 g/m². The low solution viscosity of the grade permits a 200–250 lines/cm gravure cylinder to run at production solids without streaking or doctor-blade chatter. Seal strength is measured by ASTM F88/F88M-23; a formulation containing 15 phr acetyl tributyl citrate typically reaches 4–6 N/15 mm seal strength at 95–110°C sealing bar temperature, 0.5 s dwell, and 0.3 MPa jaw pressure. Block resistance of the coated foil is evaluated at 40°C and 80% RH; without slip additive, plasticized PVB coatings can develop blocking because the plasticizer lowers the effective glass transition temperature. Static coefficient of friction of coated foil with erucamide is typically 0.35–0.50 under ISO 8295:1995, whereas unmodified coatings may exceed 0.80. Mowital G 13 provides a balance between hot-tack adhesion and solvent release, but for retortable lidding the coating must be crosslinked with polyisocyanate or overlaid with a two-component polyurethane to prevent seal weakening at 121°C. Food-contact status must be confirmed under EU 10/2011 and FDA 21 CFR 175.300 for each specific formulation because the plasticizer and slip agent are usually the limiting migrants in extraction testing.
Precision glass fabricators apply Mowital G 13 as a strippable protective film during grinding, polishing, and shipping of optical components. A spray-grade solution is prepared at 10–15 wt% solids in ethanol/isopropanol, with dibutyl sebacate or triethylene glycol bis(2-ethylhexanoate) at 10–25 phr on binder solids. Dry film thickness is controlled between 25 μm and 75 μm. At 10 phr plasticizer, removal can proceed by brittle fragmentation, which is acceptable for temporary edge masking but unsuitable for large flat surfaces. At 25 phr, the film peels continuously from glass but may leave plasticizer migration marks on polished surfaces if left in place longer than 30 days. The protective film is tested for flexibility by ISO 1519:2011 and for substrate adhesion by ISO 2409:2020. Mowital G 13 is not sufficiently photochemically stable for permanent outdoor glazing; benzotriazole UV absorbers at 0.5–2 phr delay yellowing but do not eliminate long-term embrittlement. The coating should not be used on polycarbonate without a barrier primer because the alcohol solvent can induce crazing, and the PVB film itself has limited plasticizer compatibility with polycarbonate.
On oak and meranti, a 10 wt% Mowital G 13 sealer in 90:10 ethanol/isopropyl alcohol shows a flow time of 20–30 s in a 4 mm cup under ISO 2431:2019. The sealer fills pores and is dry to sand within 20–30 min at 20°C and 50% RH. Mowital G 13 reduces grain raise when compared with nitrocellulose-only sealers because the ethanol-rich system swells wood less than ketone-heavy formulations. Sanding response is influenced by the acetal functionality of the PVB; the sealer builds film hardness quickly without blocking sandpaper when applied at 80–120 g/m² wet coat weight. Intercoat adhesion to UV-curable topcoats is checked by ISO 2409:2020 after 24 h cure. Mowital G 13 has limited resistance to water and ethanol after film formation and is not suitable for exterior joinery without crosslinking. For improved solvent resistance, 5–10 phr of a blocked polyisocyanate can be added and cured at 120°C for 20 min, but this bake exceeds normal furniture finishing conditions and is limited to industrial flat-line processes. The sealer should not be formulated with amine-catalyzed UV resins in the same wet film, because residual acid species from the PVB can interfere with cationic photoinitiator efficiency.
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Mowital G 13 is a polyvinyl butyral resin supplied as a free-flowing granulate. The grade is positioned in the low-viscosity segment of the Mowital range and is typically specified where high solution solids and low solvent demand are required in solvent-based printing inks, wash coats, and adhesion primers. The designation corresponds to a nominal solution viscosity of 13 mPa·s when measured as a 10 wt% solution in ethanol at 20 °C by DIN 53015. The polymer is produced by acetalization of polyvinyl alcohol with butyraldehyde and contains vinyl butyral, vinyl alcohol, and vinyl acetate units in the backbone. Residual hydroxyl functionality is moderate, which limits hydrogen-bonding density and influences solubility, crosslinking, and adhesion to polar substrates.
Granule morphology differentiates Mowital G 13 from powder grades in the same viscosity range. The product is intended for automated dosing and gravimetric feeding systems because it produces lower dust burden during drum handling, vacuum transfer, and hopper discharge than fine powder forms. Apparent density is normally measured by DIN 53468 and falls in the range of 300–500 kg/m³ for granular polyvinyl butyral grades. If storage humidity exceeds 60 % RH, the resin should be pre-dried at 60 °C for at least 2 h in dehumidified-air drying before solution preparation to prevent haze and undissolved gel specks. Extended exposure to moisture can increase blocking tendency in warehousing and reduce free-flow characteristics in screw feeders.
Solution preparation is normally carried out in closed agitated vessels charged with a solvent blend rather than by dry addition to pure ethanol under high shear. Dissolution is completed at 40–50 °C with moderate turbine agitation. Prolonged processing above 70 °C in acidic solvent systems is not recommended because acetal hydrolysis can liberate butyraldehyde and reduce final solution viscosity stability. Batch filtration through 10–20 µm bag filters is commonly used to remove minor gel contamination before ink letdown. The low-viscosity character of Mowital G 13 reduces solvent retention in high-solids solutions and permits shorter dissolving cycles than higher-viscosity Mowital B grades.
In flexographic printing, Mowital G 13 is used as the film-forming binder in alcohol/ester-based inks for corona-treated polyolefin and polyester films. A typical starting solution contains 20–30 wt% resin solids in a blend of ethanol, ethyl acetate, and n-propyl acetate. The solution viscosity can be measured by ISO 3219 at 23 °C and a shear rate of 100 s⁻¹. Because the grade exhibits low shear viscosity, formulators can operate at higher non-volatile content than with Mowital B 30 H while maintaining equivalent press viscosity. This reduces the quantity of volatile solvent required to reach application viscosity and assists compliance with solvent emission limits in printing operations governed by industrial emission directives.
At press, viscosity is often adjusted to 18–25 s using a DIN 53211 cup with 4 mm orifice at 23 °C. Mowital G 13 solutions remain close to Newtonian behaviour across the shear range encountered in chambered-doctor blade systems and engraved anilox rolls. Pigment concentrates are produced on horizontal bead mills with 0.6–0.8 mm zirconia beads at tip speeds of 10–12 m/s. The binder solution before milling is commonly held at 0.5–1.0 Pa·s at 100 s⁻¹ to balance wetting and throughput. After application on corona-treated polypropylene using an anilox volume of 8.0 cm³/m², the printed film is dried between stations at 60–80 °C with flash-off times of 0.5–1.5 s per station. Published data for this specific configuration is limited; therefore final anilox selection and drying capacity should be confirmed by press trial on the target substrate.
The resin can be combined with nitrocellulose, ketone resins, and monomeric plasticizers in solvent-based flexographic formulations. Compatibility with nitrocellulose is controlled by the solvent balance; a 1:1 solids blend dissolved in an ethyl acetate/ethanol mixture at 80:20 mass ratio is checked after 24 h at 20 °C for clarity and phase separation. In a starting formulation, Mowital G 13 may be present at 8–12 wt% of total ink, nitrocellulose at 5–8 wt%, plasticizer at 3–6 wt%, and pigment at 15–25 wt%. Final rheology is adjusted with n-propyl acetate or ethoxypropanol. The low-viscosity binder contributes to resolubility, pigment wetting, and adhesion, but high pigment loadings require evaluation of dispersion stability and film cohesion.
| Property | Method | Mowital G 13 | Mowital B 14 S | Mowital B 30 H |
|---|---|---|---|---|
| Solution viscosity, 10 wt% in ethanol at 20 °C | DIN 53015 | 11–15 mPa·s | 12–16 mPa·s | 25–35 mPa·s |
| Residual polyvinyl alcohol content | DIN 53240 | 9–13 wt% | 14–16 wt% | 18–21 wt% |
| Glass transition temperature | ISO 11357-2 | 63–67 °C | 66–70 °C | 70–74 °C |
| Apparent density | DIN 53468 | 300–500 kg/m³ | 300–500 kg/m³ | 300–500 kg/m³ |
| Ash content | ISO 3451-1 | ≤0.5 % | ≤0.5 % | ≤0.5 % |
The matrix is provided for orientation only. Lot-specific certificates of analysis govern for formulation calculations, and values can shift with production site and analytical method version. The differentiator for Mowital G 13 is not solely viscosity: the granular physical form and lower residual hydroxyl content separate it from B 14 S and B 30 H in automated handling and in end-use chemical resistance. Published data for this specific configuration is limited for molecular weight distribution, plasticizer uptake, and film mechanical properties; these parameters should be measured against the target application rather than inferred from nominal grade class.
Adhesion primers based on Mowital G 13 are applied by gravure or reverse-kiss coating on corona-treated polyester and oriented polyamide. A dry film weight of 2.0–3.0 g/m² is typical before deposition of barrier topcoats or metallization. Cross-cut adhesion is assessed according to ISO 2409 after 24 h conditioning at 23 °C and 50 % RH. If the substrate wetting tension falls below 38 mN/m, interfacial failure can occur even when the primer film is within specification. Primers are dried in multi-zone ovens with web temperatures from 60 °C to 80 °C and total residence times of 2–3 s. The low-viscosity resin allows stable gravure transfer at high coating speeds, but film toughness and solvent resistance are lower than for higher molecular weight PVB grades unless crosslinking is introduced.
Mowital G 13 contains fewer residual hydroxyl units than Mowital B 30 H. In thermally cured or two-component isocyanate systems, the available hydroxyl value should be obtained from the certificate of analysis using DIN 53240 and used to calculate the NCO/OH mixing ratio. At equal resin solids and equivalent stoichiometry, the crosslink density of a G 13-based film is lower than that of a B 30 H-based film. Solvent resistance measured by methyl ethyl ketone double rubs under ASTM D7835 may therefore be insufficient for applications requiring high chemical resistance unless the crosslinker level is increased or a higher-hydroxyl grade is selected. The resin is not a direct substitute for plasticized polyvinyl butyral sheet used in safety-glass interlayers, which is governed by ISO 12543-2.
Aromatic hydrocarbon tolerance is limited. Addition of toluene, xylene, or white spirit beyond approximately 10 wt% of the solvent blend can reduce solubility and cause precipitation or gelling in concentrated solutions. Aliphatic hydrocarbons are non-solvents and should be limited to minor diluent fractions in letdown. Strongly basic additives, including amine-functional dispersants and morpholine-based pH buffers, should be avoided because they can catalyse acetal hydrolysis during storage and reduce viscosity stability. Acidic catalytic formulations should be kept below 60 °C for prolonged storage to avoid butyraldehyde formation. For direct food-contact printing, compliance to Regulation (EU) 10/2011 or FDA 21 CFR 175.300 must be demonstrated on the finished package; the resin supplier safety data sheet and food-contact declaration remain normative for the specific lot and conversion process.
