| HS Code | 440471 |
| Product Name | PVB WW-A-30 |
| Material Type | Polyvinyl Butyral resin |
| Appearance | White powder |
| Viscosity | 30 mPa·s (10 wt% ethanol solution, 20°C) |
| Molecular Weight | 30,000 g/mol (approximately) |
| Hydroxyl Group Content | 18.0 - 20.0 wt% |
| Glass Transition Temperature | 66°C |
| Density | 1.08 g/cm³ |
| Water Content | ≤2.0% |
| Solubility | Soluble in ethanol, methanol, propanol, and other alcohols; insoluble in pure water |
| Refractive Index | 1.49 |
| Elongation At Break | 50% |
As an accredited PVB WW-A-30 factory, we enforce strict quality protocols—every batch undergoes rigorous testing to ensure consistent efficacy and safety standards.
| Packing | PVB WW-A-30 is packaged in 25 kg sealed polyethylene-lined bags, ensuring safe handling and moisture protection. |
| Container Loading (20′ FCL) | PVB WW-A-30 loaded in a 20′ FCL as palletized, shrink-wrapped bags, secured to prevent shifting and protected from moisture. |
| Shipping | PVB WW-A-30 is a polyvinyl butyral resin supplied as a white, free-flowing powder in sealed bags. Ship in dry, well-ventilated containers, protected from moisture and excessive heat. Generally non-hazardous and not regulated as dangerous goods, but keep away from ignition sources and handle with standard industrial hygiene measures. |
| Storage | Store PVB WW-A-30 in a cool, dry, well-ventilated area away from heat, sparks, open flames, and direct sunlight. Keep containers tightly sealed to prevent moisture absorption and contamination. Avoid contact with strong oxidizers. Maintain stable temperatures, preferably below 25°C, and use proper labeling to ensure safe handling. |
| Shelf Life | PVB WW-A-30 has a shelf life of two years when stored sealed in original packaging in a cool, dry place. |
Plasticized PVB WW-A-30 for architectural and automotive laminated glazing is processed as a cast sheet through a co-rotating twin-screw compounding line with L/D 44:1 and downstream chill-roll polishing. The resin is pre-dried at 60–65 °C for 4–6 h until free moisture is below 0.2 wt%, because water above that threshold creates autoclave blister defects and glass-to-interlayer interfacial haze. In interlayer formulation, PVB WW-A-30 is dry-blended with triethylene glycol bis(2-ethylhexanoate) or tetraethylene glycol di-n-heptanoate at 100:25 to 100:35 by mass; below 25 phr plasticizer, the sheet exhibits excessive stiffness and poor de-airing, while above 35 phr the glass transition temperature drops low enough that edge flow and thickness variation exceed 0.05 mm across a 300 mm glass stack after autoclave. The melt is extruded at barrel temperatures between 160 °C and 210 °C through a flat die held at 190–220 °C and polished between chilled rolls to produce 0.38 mm, 0.76 mm, and 1.52 mm interlayer sheet. After conditioning at 18–23 °C and 25–30% RH to control tack, the sheet is laid between cleaned glass plies, de-aired by nip roller or vacuum bag, and laminated in an autoclave at 130–140 °C and 1.0–1.2 MPa for 60–90 min. Compliance is anchored to ISO 12543-2:2021 for interlayer optical quality, ASTM D1003-21 for haze, ASTM D638-14 for tensile properties, EN 12600:2002 for impact behavior, and ECE R43 or ANSI/SAE Z26.1-2015 for automotive glazing. Terminal products include laminated windshields, architectural safety balustrades, skylight sandwich panels, and blast-resistant glazing units. Operating boundaries apply: if warehouse relative humidity exceeds 60%, PVB sheet can reach above 1.0 wt% moisture within 72 h and must be vacuum re-dried, and the material should not be combined with amine-catalyzed silane adhesion promoters at high temperature because premature adhesion build-up can prevent clean autoclave de-airing.
In multilayer ceramic capacitor tape casting, PVB WW-A-30 functions as a thermoplastic binder for BaTiO3-based dielectrics at 5–8 parts per 100 parts ceramic powder by mass, with dibutyl phthalate or benzyl butyl phthalate at 2–4 parts, polyester-polyamine dispersant at 0.5–1.5 parts, and a 60:40 methyl ethyl ketone/ethanol solvent blend. The resin is pre-dissolved at 20 wt% solids before high-shear dispersion in a planetary mixer; final slurry solids are held at 55–65 wt% with viscosity between 1200 mPa·s and 2500 mPa·s at 25 °C for a doctor blade gap of 100–180 µm on a PET carrier. Initial drying in a three-zone belt oven at 60 °C, 80 °C, and 100 °C reduces residual solvent below 0.5 wt%, yielding green tape of 20–40 µm thickness with tensile strength of 1.5–3.0 MPa per ASTM D882-18. Stacked sheets are laminated at 60–80 °C and 30–50 MPa for 10–20 min before cutting to chip dimensions.
The critical process boundary is binder removal: PVB grades of this class show thermal decomposition onset near 200–230 °C and peak mass loss between 250 °C and 350 °C under air at 2 °C/min. If the ramp rate exceeds 2 °C/min, carbon residue in the dielectric rises above 0.05 wt% and green tape blistering occurs. In base-metal-electrode MLCC fabrication with Ni electrodes, burnout is carried out in humidified nitrogen containing 50–150 ppm O2, because lower O2 fails to oxidize carbon before sintering and higher O2 converts Ni to NiO at 350 °C. Specific published TGA-MS data for PVB WW-A-30 under this atmosphere are limited; the stated ranges derive from industrial PVB binders of comparable hydroxyl content and molecular weight. After binder removal, the stack is sintered at 1080–1150 °C for 2 h under reducing conditions to deliver terminal X5R and X7R MLCC chips complying with IEC 60384-1:2021. The main batch-to-batch processing risk observed on production lines is viscosity drift in the slurry, which shifts tape thickness if solvent balance deviates by more than 3 wt% ethanol during casting.
For acid-catalyzed wash primer application on 2024-T3 aluminium and steel substrates, PVB WW-A-30 is formulated as a two-component metal pretreatment at 7–8 wt% resin solids, 6–7 wt% zinc chromate or a modern zinc phosphate/zinc molybdate replacement, 1.5–2.0 wt% phosphoric acid at 85%, and a solvent mixture of isopropanol and n-butanol. The resin is dissolved separately to prevent acid-catalyzed acetal hydrolysis before spray application; once the acid component is mixed, pot life at 25 °C is typically 8–12 h, and viscosity drift measured on a Zahn #2 cup exceeds 30% after 24 h. Substrate preparation follows ISO 8501-1:2007 to Sa 2.5 or chemical conversion coating per MIL-DTL-81706 Type II, followed by spray application at 6–10 µm dry film thickness and 10–15 min flash-off before epoxy or polyurethane topcoating within 8 h. The phosphoric acid etches the metal surface and passivates corrosion products while PVB provides adhesion to the topcoat. Corrosion performance is assessed by ASTM B117-19 salt spray with scribe creep per ASTM D1654-08, and coating adhesion by ISO 2409:2020 cross-cut.
Chromium(VI)-based wash primers require site-specific REACH review under Article 57 and Article 60; the specific zinc chromate compound is examined as a carcinogenic category 1B substance and may trigger authorization or restriction duties. European applicators therefore evaluate zinc phosphate/molybdenum-based PVB wash primers with 5–7 wt% PVB WW-A-30 and 3–5 wt% zinc phosphate. Terminal products include aerospace aluminium skins, coil-coated steel, and heavy-duty vehicle cab surfaces. The process boundary is that acidic formulations must not be stored in unlined aluminium containers because hydrogen evolution and premature PVB hydrolysis generate viscosity instability and loss of anti-corrosive activity.
Alcohol-borne flexographic surface printing on corona-treated polyolefin films incorporates PVB WW-A-30 as pigment-dispersing binder at 8–12 wt% in the finished ink, alongside pigment at 15–25 wt%, nitrocellulose at 3–5 wt%, tributyl citrate at 2–4 wt%, and slip wax at 1–2 wt%. High-shear dispersion begins with a disperser tip speed of 15–20 m/s before bead milling to a Hegman gauge reading of 5–6 µm; press-side viscosity is maintained at 18–25 s on a Zahn #2 cup at 25 °C, and the pH is kept neutral to limit acetal hydrolysis. Printing on a central-impression flexographic press runs at 80–150 m/min with drying air at 50–60 °C; residual solvent on the printed film is controlled below 5 mg/m² by ASTM F1884-04. Compliance for incidental food-contact use rests on FDA 21 CFR 175.105, EU Regulation 1935/2004, and Swiss Ordinance 817.023.21. The main formulation boundary is amine sensitivity: free amine values above 10 mg KOH/g in dispersants cause viscosity creep and gelation during storage at 40 °C. Terminal products include snack food wrappers, pressure-sensitive labels, and general flexible packaging. Replacement of ethyl cellulose with PVB shifts open-time and re-solubility; if ethyl acetate content exceeds 20 wt%, press stability improves but dry film blocking resistance decreases unless slip wax is raised to 2 wt%.
Dissolved at 15–20 wt% solids in an ethanol/ethyl acetate 70:30 solvent blend with 10–20 phr citroflex plasticizer, PVB WW-A-30 forms a heat-seal lacquer for 20–25 µm aluminium foil. Gravure coating with a 60–80 l/cm cylinder deposits 2–4 g/m² dry coat weight, followed by drying at 80–120 °C to residual solvent below 0.5 wt%. The coated foil is sealed to PVC/PVDC blister cavities at 170–190 °C, 0.3–0.6 MPa, and 0.5–1.0 s dwell; peel strength measured by ASTM F88/F88M-21 falls between 4 N/15 mm and 7 N/15 mm. The governing food-contact standard is FDA 21 CFR 177.1580. The process boundary is moisture absorption in the PVB powder; at relative humidity above 60%, re-drying at 60 °C for 4 h is required to prevent pinhole coating defects.
In water-slide ceramic and glass decal manufacturing, PVB WW-A-30 functions as the thermoplastic covercoat binder at 3–6 wt% in the covercoat solution, with plasticizer at 0.5–1.5 wt% to maintain elongation above 120% during slide-off. The covercoat is printed through 77T–120T polyester mesh onto the ceramic pigment decal and dried at 25–30 °C for 30–60 min; it then transfers to glass or ceramic ware by water immersion and hand or machine slide-off. Firing must include a controlled ramp at 3–5 °C/min through 250–400 °C to depolymerize and volatilize the PVB; a plateau at 180–220 °C before ramp reduces edge curling and splitting of the covercoat. For borosilicate glass, peak firing is held at 580–620 °C for 10–20 min; for ceramic tableware, peak firing at 780–820 °C removes residual carbon and sinters the decorative enamel. Compliance is tested under ISO 6486-1:1999 for lead and cadmium release from ceramic and glass food-contact decoration, with additional limits from Regulation (EC) 1935/2004. Incomplete burnout below 500 °C leaves carbon residue as black specks and reduces gloss, so the binder is unsuitable for low-fire enamels. Terminal products include decorated glass bottles, borosilicate laboratory ware, ceramic tableware, and architectural glass panels.
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Polyvinyl butyral resin supplied under the designation PVB WW-A-30 is a controlled-hydroxyl acetal resin manufactured by condensation of poly(vinyl alcohol) with butyraldehyde. The grade is positioned as a medium-viscosity material for solventborne coatings, gravure and flexographic inks, ceramic binders and temporary protective films. Its balance of residual hydroxyl, acetyl and acetal functionalities influences solubility, adhesion to glass and metal oxides, film toughness and crosslink reactivity. The resin is normally supplied as a white, free-flowing powder with a bulk density in the range of 0.25–0.45 g/cm³; particle size distribution and moisture content vary by batch. Moisture above 0.5 wt% can slow dissolution in ethanol/toluene blends and promote microgel formation in ketone-containing solvent systems. Drying at 40–50 °C for 2–4 h before formulation is standard when ambient humidity exceeds 60% RH.
| Parameter | Method or condition | Reference range |
|---|---|---|
| Volatile matter | ISO 3251, 105 °C, 2 h | ≤ 0.5 wt% |
| Residual hydroxyl as PVOH | DIN 53240-1 | 18–21 wt% |
| Acetate content | Producer saponification method | 1–3 wt% |
| Butyraldehyde acetal content | Producer method | 75–82 mol% |
| Solution viscosity | 10 wt% in 95% ethanol, 25 °C, Brookfield LV | 25–40 mPa·s |
| Glass transition temperature | ISO 11357-2:2020, second heating, 10 K/min | 65–75 °C |
| Ash content | ISO 3451-1, 600 °C, 2 h | ≤ 0.1 wt% |
Published product-specific data for PVB WW-A-30 in independent interlaboratory studies is limited; the envelope above represents the ordinary range for medium-viscosity PVB resins, not a certified lot value. Formulators should always verify batch-specific certificates of analysis before qualifying the material for production.
In a 60:40 ethanol/toluene binary solvent, PVB WW-A-30 dissolves under high-shear agitation. Batch-charging at a low powder feed rate, typically 2–3 kg/min into a 30 L disperser with a Cowles blade operating at a tip speed of 15–20 m/s, yields lump-free solution in 45–60 min. The addition sequence is critical: when toluene is charged before ethanol, polymer wetting is slower and viscosity build-up can exceed 20 Pa·s because of temporary hydrogen-bonded gel networks. Temperature rise during dissolution should be controlled below 40 °C to avoid solvent loss and surface skinning; jacketed vessels or low-shear sweep agitation after initial dispersion are used. Filtration through a 50 µm bag or cartridge removes residual gel particles. Sealed solution storage at 20–25 °C is commonly 6 months, but acidic impurities below 0.05 wt% can trigger slow acetal hydrolysis and reduce solution viscosity.
The residual hydroxyl groups in PVB WW-A-30, expressed as 18–21 wt% poly(vinyl alcohol) equivalent, provide reactive sites for condensation with phenolic resols, melamine-formaldehyde resins, isocyanates and silane adhesion promoters. In stoving enamels, the hydroxyl functionality participates in etherification and transetherification reactions; cure temperatures below 140 °C often leave unreacted PVB domains that plasticize the film and reduce solvent resistance. When formulated with a butylated melamine resin at 10–20 phr on PVB solids, a peak metal temperature of 180–200 °C for 90–120 s is typical in coil coating lines to achieve methyl ethyl ketone double-rub resistance above 50 cycles under ASTM D5402. Lower hydroxyl PVB grades generally require higher melamine content or sulfonic acid catalysis to reach comparable crosslink density, but excess catalyst increases film discoloration above 190 °C.
A process conflict arises from residual butyraldehyde in the resin. Aldehyde residuals above 0.1 wt% can scavenge primary amines and retard cure in two-pack epoxy/PVB hybrid systems. This imposes an operational boundary: PVB WW-A-30 should not be preblended with amine curatives before use, because premature Schiff-base formation increases mixed viscosity and shortens pot life. In isocyanate-cured systems, the same hydroxyl groups accelerate urethane formation, but moisture above 0.05 wt% in the solvent blend can consume isocyanate and generate carbon dioxide pinholes in cast films.
Compared with low-hydroxyl PVB grades containing 11–15 wt% PVOH equivalent, PVB WW-A-30 shows higher tensile strength and better adhesion to aluminium, cold-rolled steel and glass when assessed by pull-off testing under ASTM D4541. However, the higher hydroxyl content also increases water sensitivity of un-crosslinked films. Water absorption of a clear film after 24 h immersion in deionised water at 23 °C may rise to 2–5 wt% unless an epoxy or melamine crosslinker is present. Differences in solvent solubility are pronounced: lower-hydroxyl PVB resins tolerate higher aromatic hydrocarbon fractions, while PVB WW-A-30 may require at least 40–60 wt% polar solvent such as ethanol, isopropanol or methyl ethyl ketone to maintain clarity. In gravure printing inks, ester solvents such as ethyl acetate are limited to 15–25 wt% of the solvent blend to avoid resin precipitation when aromatic dilution is introduced later.
Differences from higher-viscosity grades are observed in film formation. A 10 wt% solution of PVB WW-A-30 at 25 °C gives viscosity of 25–40 mPa·s, enabling higher solids in sprayable coatings than a 60 mPa·s grade. The trade-off is reduced green strength and greater thermoplastic flow during baking; rheology control may require fumed silica at 0.5–1.5 wt% on total formulation or a microcrystalline wax dispersion.
PVB WW-A-30 is not typically processed as a neat resin without plasticizer. In thermoplastic applications, plasticizer loading between 15–30 wt% of triethylene glycol bis(2-ethylhexanoate) or dibutyl sebacate lowers processing temperature to 160–190 °C in a twin-screw extruder with L/D ratio of 44:1 and screw speed of 200–400 min⁻¹. The melt is shear-thinning; apparent viscosity at 190 °C and 100 s⁻¹ may fall from 8,000–12,000 Pa·s for neat resin to 1,500–3,000 Pa·s at 25 wt% plasticizer. Residence time above 210 °C must be limited to 2–3 min to suppress acetic acid elimination and butyraldehyde evolution, which causes yellowing and pinholes in extruded sheet. Venting through a vacuum port at −0.08 to −0.09 MPa removes volatiles; inadequate devolatilization produces surface defects in subsequent thermoforming. For PVB WW-A-30 specifically, published data for this configuration is limited; lot-to-lot molecular weight variation can shift the processing window by 5–10 °C.
Melt flow rate measured under ISO 1133-1:2022 at 190 °C and 2.16 kg is not commonly used for plasticized PVB because condensation and plasticizer exudation distort results; capillary rheometry per ISO 11443 is preferred. Neat PVB thermal degradation in air is measured by thermogravimetric analysis, with onset of mass loss near 200 °C and main decomposition between 300 °C and 500 °C.
In anti-corrosion shop primers and wash primers, PVB WW-A-30 is dissolved into alcohol-toluene blends and combined with zinc phosphate or zinc tetraoxychromate to produce thin films of 8–15 µm dry thickness. The resin functions as a temporary binder with adhesion to blast-cleaned steel and as a carrier for phosphoric acid etchants; adhesion after salt spray per ISO 9227 is typically assessed at 240–500 h depending on inhibitive pigment content, although published data for this specific configuration is limited. In dual-layer systems, overcoating with epoxy or polyurethane requires residual acid and alcohol removal, usually by forced drying at 60–80 °C for 10–15 min, to prevent intercoat delamination. Ceramic binder applications exploit the clean burnout of PVB; thermogravimetric analysis at 10 K/min in air shows complete decomposition between 250 °C and 550 °C with ash below 0.1 wt%, which is critical for alumina and barium titanate tape casting.
In multilayer glass interlayers, PVB resins are plasticized to 20–28 wt% and extruded into sheet; however, PVB WW-A-30 is not generally regarded as an interlayer grade because its molecular weight is lower than typical interlayer resins, and published data for this specific configuration is limited. Its use is therefore concentrated in coatings, inks, binders and temporary protective films rather than load-bearing laminated glazing.
Replacement of a low-hydroxyl PVB resin with PVB WW-A-30 in a two-pack phosphoric acid wash primer alters acid demand and pot life. The higher hydroxyl concentration consumes more phosphoric acid through phosphate ester formation; acid addition may need to be reduced from 8–10 wt% to 5–7 wt% on total formulation to avoid excessive water uptake and early adhesion loss. The viscosity build of the mixed primer after 30 min is steeper because of PVB-phosphoric acid hydrogen bonding; a reduction in solids of 1–2 wt% or an increase in ethanol content by 5–10% maintains sprayability. In zinc-rich primers, PVB WW-A-30 supports zinc dust loadings up to 80–85 wt% of dry film, but its higher polarity can increase moisture retention at the zinc interface. For blast-cleaned steel with a surface profile of 50–75 µm, dry film thickness of 15–25 µm is used to bridge peaks; lower-viscosity PVB grades may give smoother films but less sag resistance on vertical sections. Surface profile is verified with ASTM D4417 replica tape.
Storage of PVB WW-A-30 requires sealed containers in areas below 30 °C and 60% RH. The powder is combustible as an organic dust; electrostatic accumulation during pneumatic conveying should be controlled below 0.1 mJ minimum ignition energy, and inerting is advisable where dust clouds exceed 30 g/m³. Regulatory compliance is batch-specific: REACH registration for the polymer requires traceability of the butyraldehyde and vinyl acetate monomer precursors, while RoHS 2011/65/EU Annex II restricts lead, cadmium, mercury and hexavalent chromium concentrations. For food-contact uses, PVB may be evaluated under FDA 21 CFR 175.105 adhesives or 21 CFR 177.1670 film provisions only when the finished formulation meets extraction limits; unplasticized PVB WW-A-30 is not intended for direct food-contact films without additional migration testing under EU 10/2011.
