| HS Code | 919689 |
| Chemical Composition | Carboxylated polyvinyl acetate copolymer with reactive carboxyl functional groups |
| Physical Form | White milky aqueous dispersion or emulsion |
| Solids Content | Typically 50-55% by weight |
| Viscosity | Moderate, typically 1000-5000 mPa·s at 25°C |
| Ph | Acidic to neutral, typically 4.0-6.0 |
| Glass Transition Temperature | Approximately 5-15°C depending on copolymer formulation |
| Crosslinkability | Can crosslink via carboxyl groups with multifunctional reactive agents such as aziridines, melamines, or metal oxides |
| Film Formation | Forms clear, flexible films at room temperature or upon mild heating |
| Adhesion | Excellent adhesion to porous substrates such as paper, wood, and textiles |
| Water Resistance | Crosslinked films exhibit significantly enhanced water and moisture resistance |
| Mechanical Strength | Good tensile strength and toughness after crosslinking |
| Storage Stability | Stable for at least 6 months when stored in closed containers at 5-35°C |
As an accredited Crosslinkable Carboxylated PVAc factory, we enforce strict quality protocols—every batch undergoes rigorous testing to ensure consistent efficacy and safety standards.
| Packing | Supplied in 200 kg sealed drums, protected from moisture and contamination to ensure stable crosslinkable carboxylated PVAc performance. |
| Container Loading (20′ FCL) | Container Loading (20′ FCL): Crosslinkable Carboxylated PVAc packed in drums on pallets, stowed and braced to prevent movement during transit. |
| Shipping | Crosslinkable Carboxylated PVAc is shipped in sealed drums or IBC totes, kept upright to prevent leakage. Transport at ambient temperature, avoiding freezing or excessive heat. Material is generally non-hazardous under ADR/IMDG; however, SDS, labels, and spill containment should accompany all shipments. Protect from moisture and incompatible materials during transit. |
| Storage | Store Crosslinkable Carboxylated PVAc in tightly sealed containers in a cool, dry, well-ventilated area away from direct sunlight, heat, and open flames. Maintain temperatures between 5–35°C; avoid freezing. Keep away from strong oxidizers and alkaline materials. Use within recommended shelf life, and stir gently before use if separation occurs. |
| Shelf Life | Store in a cool, dry area away from sunlight. Shelf life is typically 12 months from manufacture when container remains sealed. |
In edge-glued beech and oak panel production, carboxylated PVAc base dispersions with solids content 50–55%, particle size 0.5–2.0 µm, and pH 3.5–4.5 are handled as two-part systems because the carboxyl functionality remains storage-stable until an acidic aluminum chloride complex hardener is introduced. The hardener is metered at 4.0–8.0 parts by wet weight per 100 parts dispersion immediately upstream of a through-feed roller coater. Pot life after addition is 45–90 min at 20 °C; viscosity rise follows a nonlinear path as Al³⁺ coordinates with carboxyl groups, and chilled two-component storage at 10–15 °C is standard where shift output exceeds pot-life capacity. Adhesive spread rate is adjusted by surface roughness and equilibrium moisture content: 120–160 g/m² for planed softwood, 150–200 g/m² for sanded beech, and 180–220 g/m² for oak above 12% moisture. Bonded test assemblies prepared and tested according to EN 205:2016 are used to verify shear resistance, while classification follows EN 204:2016; formulations at the upper hardener ratio and hot-cured at 45–60 °C reach D3, with select two-part systems meeting D4 performance in boiling-water resistance testing. Cold-press laminating cells operate at 0.6–1.0 N/mm² for softwood and 0.8–1.4 N/mm² for hardwood, with clamp times of 20–40 min at 20 °C. Hot-platen cycles at 60–70 °C reduce clamping to 8–15 min, while high-frequency edge gluers using 13.56 MHz generators cure glue lines in 3–6 min; glue-line thickness must remain below 0.3 mm to avoid uneven dielectric heating. Amine-based thickening agents must not be used in the base dispersion because they interfere with metal-carboxyl crosslinking and reduce D3/D4 water resistance. If mixed adhesive remains in the coater sump beyond pot life and pH drops below 2.5, partially gelled particles transfer to board edges and produce visible glue lines after sanding. Resulting downstream finished articles include edge-glued solid wood panels, finger-jointed door stiles, laminated stair treads, and solid wood tabletops for furniture and interior joinery.
In spunlace and airlaid nonwoven lines, crosslinkable carboxylated PVAc binders are applied at 14–22% dry weight add-on to the fibrous web, with a methylated melamine-formaldehyde crosslinker dosed at 5–8 parts per 100 parts dry binder solids and magnesium chloride hexahydrate catalyst at 0.5–1.0 part per 100 parts binder solids. Foam application with blow ratio 3:1–5:1 is preferred over dip-nip saturation for low-weight carded webs because it limits fiber-to-fiber bridging and reduces drying load. The downstream curing stage on a through-air drum dryer uses three zones at 120 °C, 140 °C, and 155 °C, with total residence time 40–90 s; residual moisture is controlled to 2–4% before winding. Wet strength retention is evaluated under EDANA/INDA WSP 110.4 strip tensile testing, and dry tensile is reported according to ISO 9073-3:1989. Cosmetic finished wipes must satisfy Regulation (EC) No 1223/2009, and the binder system itself is screened under REACH Annex VII–X. Over-cure above 160 °C causes measurable wet-strength loss and yellowing from chain scission, while under-cure below 130 °C leaves unreacted methylol functionality that promotes blocking and odor in roll storage. Formaldehyde release limits for cosmetic nonwovens are set by the finished article regulation and require low-formaldehyde or formaldehyde-sequestered crosslinker grades. Terminal types include wet floor wipes, household cleaning cloths, spunlace facial mask sheet substrates, and industrial wiping products requiring temporary wet integrity during storage and use.
In three-ply folding boxboard coating kitchens, carboxylated PVAc is used as a co-binder in the pre-coat at 12–18 parts per 100 parts kaolin or ground calcium carbonate pigment, and in the top-coat at 10–14 parts per 100 parts pigment. Ammonium zirconium carbonate crosslinker is added at 0.5–2.0 parts per 100 parts binder solids after the coating color pH is adjusted to 8.5–9.0; total coating color solids are held at 58–64%. Blade coasters running folding boxboard at basis weight 230–350 g/m² and line speeds of 400–1000 m/min transfer the coating, followed by infrared dryers and air flotation sections that raise web surface temperature to 120–170 °C. Crosslinker addition affects IGT dry pick resistance measured under ISO 3783:2006 and directly determines wet-pick and wet-rub boundaries during offset printing. Under-addition leaves unreacted carboxyl sites that swell at the coating surface and lift on offset blankets; over-addition above the stated range causes pH drift and viscosity instability in the circulation tank, increasing blade scratches and backing-roll contamination. Food-contact compliance for finished folding cartons is anchored to FDA 21 CFR 176.170 and FDA 21 CFR 176.180 for dry and aqueous foods, and to Regulation (EU) No 1935/2004 for European food-contact articles. Terminal downstream products include oil-resistant folding cartons for dry and fatty food packaging, book covers with printed surface durability, and paperboard packaging where offset reprocessing resistance is required.
On central impression flexographic presses running surface-printed polyolefin films, carboxylated PVAc functions as both pigment-wetting resin and film former after neutralization with ammonium hydroxide to pH 8.2–8.8. Resin usage is 18–28 parts per 100 parts finished ink, and zinc ammonium carbonate crosslinker is post-added at 0.3–1.0 part per 100 parts ink with continuous pH monitoring. Chamber doctor blade systems deliver the ink to anilox rolls engraved at 200–250 LPI and cell volume 10–12 cm³/m²; corona treatment of polyethylene or polypropylene is maintained at 38–42 mN/m before printing. Drying tunnel air temperatures are set to 60–80 °C with contact time 0.5–2.0 s, sufficient to remove ammonia and initiate carboxyl-metal crosslinking without film blocking on rewind. Print adhesion is verified by tape removal according to ASTM F2252-13, and residual solvent is managed within the packaging requirement of EU 94/62/EC; heavy metal limits for packaging inks must also meet Directive 94/62/EC Article 11 and REACH Article 67 restrictions. Operational boundaries are narrow: crosslinker addition above 1.0 part per 100 parts ink produces viscosity rise exceeding 20% within 4 h, and emulsion freeze-thaw instability occurs below 5 °C unless propylene glycol is added at 3–5% of total formulation. Terminal finished product types include surface-printed LDPE hygiene packaging films, paper label topcoats, and water-based overprint varnishes applied to flexible substrates where heat-seal resistance after printing is not required.
Flooded-nip binder application on wet-laid glass mats uses carboxylated PVAc at 4–12% dry weight add-on for mat weights ranging from 30–100 g/m², with a melamine-formaldehyde crosslinker at 5–10 parts per 100 parts dry binder solids. Vacuum slot de-watering immediately after the flooded nip is operated at 0.4–0.8 bar; excessive vacuum draws binder to the wire side and creates two-sided mat properties, while insufficient vacuum leaves surface puddles that increase blocking in roll form. Through-air drying follows at 180–220 °C for 10–30 s, with cure completeness checked by measuring hot-water extraction loss rather than visual dryness. Tensile breaking force of the finished mat is determined under ISO 3342:2011, and where mats enter PVC cushion vinyl flooring, heavy metal and restricted substance compliance is managed under REACH and, where applicable, RoHS Directive 2011/65/EU for assembled electrical or electronic components. Over-cure above 220 °C embrittles the PVAc film and reduces tear resistance, while under-cure leaves a moisture-sensitive binder that re-disperses during flooring lamination. Terminal article types include glass fiber veils used as PVC cushion vinyl reinforcement, roofing carrier mats, acoustic ceiling tile facers, and nonwoven glass mat substrates for composite tooling surfaces.
Spiral tube winders operating at 20–60 m/min apply carboxylated PVAc adhesive to paper plies through a steel roll applicator; base viscosity is controlled between 3000–6000 mPa·s and solids between 48–52%. Aluminum nitrate hardening agent is added at 2–4 parts per 100 parts wet adhesive and reduces open time; mixed adhesive must be consumed within 30–60 min because viscosity rises rapidly after the carboxyl groups begin ionic crosslinking. Paper moisture content above 10% retards cure and reduces interlaminar shear, while moisture below 6% causes adhesive skin-over before ply consolidation. Adhesive performance is not regulated as a food-contact material in core winding; packaging waste compliance for the finished tube is addressed under EU 94/62/EC, and substance registration is handled through REACH. The process is sensitive to ambient relative humidity: production bays above 60% RH require pre-drying of the outer paper plies to prevent caliper swell and glue-line dilution. Terminal downstream articles include paper cores for flexible packaging films, composite can bodies, industrial paper tubes for yarn winding, and spiral-wound cores used in pressure-sensitive label converting.
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Crosslinkable carboxylated poly(vinyl acetate) dispersion, designated here as CPVAc-2510, is an aqueous copolymer of vinyl acetate and a carboxylic acid-functional vinyl monomer. The product is supplied as a milky white liquid with solids content of 50–55 wt% measured by ISO 3251, pH of 3.5–5.0 by ISO 976, and Brookfield RVT viscosity of 3000–7000 mPa·s at 20 rpm and 25 °C using ISO 2555. Minimum film formation temperature is 10–18 °C per ISO 2115, and density is 1.07–1.10 g/cm³ per ISO 2811. The acid value of 10–25 mg KOH/g indicates the reactive carboxyl density. Residual vinyl acetate monomer is controlled below 0.1 wt% by gas chromatography according to ISO 13741. The grade is differentiated from PVAc homopolymer dispersions by the presence of pendant -COOH groups that can form ionic or covalent networks after drying; this functional response is the basis for its use in laminating adhesives, wood-bonding formulations, and saturated nonwoven binders.
Vinyl acetate is copolymerized with a carboxylic acid-functional comonomer, most commonly acrylic acid or crotonic acid, to introduce pendant -COOH groups along the polymer chain. The acid value of 10–25 mg KOH/g corresponds to a carboxyl density sufficient for post-polymerization crosslinking without destabilizing the emulsion. By comparison, a conventional PVAc homopolymer typically exhibits an acid value below 3 mg KOH/g and remains thermoplastic after drying. The carboxylated architecture permits formation of ionic and covalent networks when the drying or dried film is exposed to ammonium zirconium carbonate, glyoxal, or selected metal salts; conventional PVAc lacks the reactive group density for this response.
This structural difference creates a processing trade-off. Carboxyl groups raise polarity and improve adhesion to oxidized metal surfaces, but they also increase water sensitivity until crosslinked. The initial dried film of CPVAc-2510 may show higher water uptake in ISO 62 immersion than a plasticized PVAc homopolymer because of unreacted carboxylate ions. Only after crosslinker reaction and adequate cure does the cured network show lower swelling and improved cohesive strength. The distinction is therefore not a simple thermoplastic-to-thermoset transition; it is a controlled shift from an acid-stabilized dispersion to a partially networked film.
The following comparative profile distinguishes the carboxylated product from adjacent vinyl acetate-based polymer dispersions used in the same coating and laminating markets.
| Property or response | Crosslinkable carboxylated PVAc | Conventional PVAc homopolymer | VAE dispersion |
|---|---|---|---|
| Acid value | 10–25 mg KOH/g | < 3 mg KOH/g | 5–20 mg KOH/g depending on grade |
| Post-addition crosslink response | Reactive with AZC, glyoxal, and selected metal salts | Negligible | Limited; requires carboxyl comonomer |
| Minimum film formation temperature | 10–18 °C per ISO 2115 | 18–20 °C | 0–5 °C |
| Water resistance after full cure | Moderate to high in formulated systems | Low to moderate | Moderate |
| Adhesion to oxidized metal foil | Improved after cure | Low | Moderate |
| Plasticizer demand | Low to moderate | High | Low |
| Film flexibility after drying | Moderate; reduced cold flow after crosslinking | High when plasticized | High |
In paper-to-board lamination and printed foil-to-paper wet bonding, the dispersion is applied at a wet film thickness of 10–18 µm with a Meyer rod or air-knife coater. The crosslinker is pre-added under gentle stirring at 25 °C; high-shear mixing is avoided because shear-induced coalescence can generate grit. Gravure application uses ceramic anilox rolls with 80–120 lines/cm and cell volumes from 18–25 cm³/m². Lower cell volumes are selected when the substrate is a high-holdout polyester film. Dryer conditions are segmented, with web surface temperature held below 85 °C in the first zone to prevent skin formation. Final laminate peel strength is evaluated by ASTM D1876; substrate fiber tear is the target failure mode on uncoated paper, while foil-to-paper bonds are inspected for ink splitting rather than adhesive peeling. Published data for this specific configuration is limited; production settings are usually validated on the target line because dryer airflow and web tension alter water release rate and surface tack.
The working range for coat weight is narrow. Below 6 g/m² dry, bond strength becomes sensitive to substrate roughness, and above 18 g/m² dry, residual water can be trapped under the film surface during high-speed drying. Trapped water slows crosslinker conversion and produces tacky roll blocking. For this reason, line speed and dryer capacity are paired rather than adjusted independently.
In spiral-wound paper tube and core lamination, the dispersion is used at 45–55% solids and can be mechanically foamed to a density of 0.6–0.8 g/cm³ before application by wheel or doctor roll. The crosslinkable grade reduces lay-flat distortion after winding because the partially cured bond line resists moisture-induced relaxation. Standard PVAc homopolymer in the same construction can exhibit greater ply springback when ambient humidity exceeds 60%; this difference is attributed to lower creep in the crosslinked film. Open tack is developed within 20–40 s at 20–25 °C depending on board absorption, after which the wound tube can be cut without edge delamination.
Ammonium zirconium carbonate is added at 0.5–2.0 wt% of dispersion solids after the pH is adjusted to 8.0–9.0. Direct addition to the as-supplied acidic dispersion causes rapid viscosity increase and coagulum. The pH window is narrow: at pH 9.5 or above, ammonia release can be excessive, and film water sensitivity may increase if residual ammonium carboxylate remains; at pH below 7.8, zirconium species begin to coordinate carboxylate groups prematurely, shortening pot life to less than 4 hours. In continuous coating trials, a pH drift of more than 0.5 units was associated with viscosity increase from 8000 mPa·s to 15000 mPa·s over a 6-hour shift and subsequent anilox plugging.
Glyoxal-based crosslinking operates under a different pH window. Addition levels are typically 0.3–1.0 wt% of dispersion solids, and the bath remains acidic to slightly acidic. At pH above 7.5, yellowing and faster viscosity build are observed; at low pH, cure is slower and can require post-drying storage at 30–40 °C for 24–48 hours to develop full water resistance. These constraints mean that a single formulation cannot simultaneously utilize both crosslinker classes without careful sequencing and pH buffering.
Equipment contact surfaces should be stainless steel or high-density polyethylene. The acidic as-supplied dispersion can corrode carbon steel and zinc-coated surfaces over extended exposure. Multivalent salts, borates, and strong acids should not be added directly because they can induce shock coagulation. If pH adjustment is required, diluted ammonia or 2-amino-2-methyl-1-propanol should be diluted to 10% concentration and added slowly under low-shear agitation.
In a carboxylated PVAc film, the total acid value measured by titration is not evenly available for crosslinking. Carboxyl groups buried in particle cores or screened by the protective colloid exhibit slower transport to the reaction front than surface carboxylates. This distribution effect is important when comparing two dispersions with identical acid values but different polymerization processes. A dispersion with 10 mg KOH/g of mostly surface-localized carboxyl groups can develop higher wet strength after cure than a dispersion with 20 mg KOH/g of largely buried groups. The product therefore cannot be selected solely on acid value; lot-to-lot variation in surface charge density, measured by conductometric titration or zeta potential, is a more informative indicator of crosslinker accessibility.
Neutralization also controls the depth and rate of cure. Partial neutralization to pH 7.0–8.5 converts carboxylic acid groups to carboxylate anions, increasing their availability for ionic crosslinking with zirconium but also increasing hydrophilicity. The drying profile then determines whether the carboxylate groups have sufficient mobility to form a network before vitrification slows diffusion. Fast drying at high air temperature can immobilize the matrix prematurely and leave unreacted crosslinker; slow drying with a humid first zone allows more uniform network formation but may create blocking on the rewind. These competing effects set the practical cure window.
Conventional PVAc wood adhesives are usually classified in the EN 204 D2 category for interior use with limited moisture exposure. Moving to EN 204 D3 requires the adhesive film to withstand short-term cold-water contact or high humidity. The carboxylated PVAc grade is formulated with a crosslinker and tested on beechwood specimens according to EN 205. After crosslinking, the cured films show less swelling and higher wet strength retention than unmodified homopolymer films, although the absolute result depends on the crosslinker type, cure temperature, and substrate moisture content. In practice, EN 204 D3 performance is achieved with glyoxal or AZC crosslinking when the adhesive is applied at 120–180 g/m² and the joint is conditioned at 20 °C/65% RH for 7 days before testing. For EN 204 D4 service, the product may require combination with a more moisture-resistant thermoset resin; the carboxylated PVAc alone is not recommended as a sole binder for continuous water immersion.
Open assembly time on beechwood at 20 °C and 65% RH is 6–10 minutes for the formulated adhesive, compared with 8–15 minutes for a plasticized PVAc homopolymer. The shorter open time arises from higher initial tack and faster surface skin formation. This difference must be considered in manual furniture assembly lines where component placement is delayed.
In dry-laid nonwoven saturation, the dispersion is diluted with demineralized water to 15–25% solids and applied by a padder or size press. Crosslinker addition at 0.5–1.5 wt% of dispersion solids improves tensile strength and solvent resistance after curing at 120–140 °C for 1–3 minutes. Tensile strength of the saturated nonwoven is evaluated by ISO 9073-3. The uncured saturated web is sensitive to high humidity; when relative humidity exceeds 60%, the web should be dried immediately to prevent re-wetting and nonuniform binder migration. Observed failure modes on production lines include streaking from bath pH drift and filter plugging from coarse coagulum; both are controlled by maintaining bath pH within 0.3 units of the set point and by using inline 100 µm bag filters.
For remoistenable adhesive films, the product is cast or coated, dried, and later reactivated with water. The carboxyl content provides ionic sensitivity; controlled crosslinking after film formation limits complete re-dissolution while still allowing tack development when moistened. Film dried at 85–95 °C for 2–4 minutes retains sufficient cold-water remoistenability under lower crosslinker dosages. Higher crosslinker dosages produce a more water-resistant film but reduce re-activation speed. This balance is process-critical and should be evaluated with the specific substrate.
Maintaining stable curtain coating viscosity during pH adjustment requires closed-loop buffer feed rather than batch-to-batch manual correction. At pH 8.5, the low-shear viscosity of the buffered dispersion rises to 9000–14000 mPa·s at 25 °C because of electroviscous effects from ionized carboxylates. The resulting viscosity can stabilize a curtain but may reduce web wetting on low-surface-energy substrates. Wetting is improved by adding a nonionic surfactant at 0.1–0.3 wt% of total formulation, but excess surfactant can depress surface tension below 38 mN/m and cause edge retraction.
Anilox cell depletion is a specific failure mode encountered when the crosslinker begins to react in the transfer nip. Partially networked particles adhere to the cell walls and reduce transfer volume. This failure is detected as a gradual decrease in coat weight at constant line speed and is corrected by lowering bath temperature to 20–22 °C or reducing crosslinker dosage to the low end of the working range. On lines equipped with 60–80 lines/cm gravure cylinders and doctor chambers, recirculation should be maintained below 40 L/min; higher shear has been associated with foam formation and viscosity loss in carboxylated dispersions.
Formulators evaluating CPVAc-2510 for packaging, wood-bonding, and nonwoven applications should verify the complete mixture against the following compliance matrix. The dispersion itself is a starting material; final suitability depends on all formula components and the intended use.
| Requirement | Relevant standard or regulation | Typical evaluation condition |
|---|---|---|
| Indirect food contact adhesive | FDA 21 CFR 175.105 | Subject to extraction limits defined in the regulation |
| EU chemical registration | REACH 1907/2006 | Substances of very high concern absent above 0.1% w/w |
| Hazardous substance restriction in electronics | RoHS 2011/65/EU | Lead, mercury, cadmium, hexavalent chromium, PBB, PBDE below thresholds where applicable |
| Residual monomer | ISO 13741 | Gas chromatographic area quantification; target below 0.1% for vinyl acetate |
| Wood adhesive classification | EN 204/205 | Beechwood tensile shear strength after prescribed water exposure |
Storage should be in sealed containers at 5–35 °C; exposure to temperatures below 0 °C can cause freeze-thaw instability and irreversible grit formation. Shelf life in unopened containers is 12 months. If the dispersion pH falls below 3.0 or viscosity rises above 10000 mPa·s before use, filtration through a 100 µm screen should be performed and the batch retested against original specification. Avoid storing formulated mixtures containing AZC for more than 72 hours; glyoxal-containing mixtures may show longer low-temperature stability but should be checked for dry residue formation before line startup.
