Emulsão Dairen DA-310 VAE

In waterborne adhesive and coating systems where low-temperature film coalescence, mechanical shear stability, and absence of volatile amine neutralizing agents are specified, Dairen DA-310 vinyl acetate-ethylene (VAE) copolymer dispersion is incorporated as a primary or co-binder. The product is supplied as a milky white liquid with a solids content of 55–57% (ISO 3251, 105°C, 2h), a pH of 4.0–5.5 (ISO 976), and a Brookfield RVT viscosity of 2000–4000 mPa·s at 23°C using spindle 3 at 20 rpm (ISO 2555). Glass transition temperature determined by differential scanning calorimetry (mid-point) is 0°C, aligning with a minimum film formation temperature of 0°C (ISO 2115). The particle surface bears carboxyl functionality, conferring anionic charge density and colloidal stability against multivalent cations up to 0.5% CaCl₂ addition. In contrast to internally plasticized polyvinyl acetate homopolymers and acrylic copolymer dispersions, DA-310’s ethylene comonomer content of approximately 15–18 wt% depresses the Tg without external plasticizer migration, enabling permanent flexibility in dried films.

DA-310 occupies a mid-range position within the Dairen VAE portfolio, differing from other grades in its balance of processability and end-use mechanicals. The table below collates manufacturer-published typical values for adjacent grades, illustrating the differentiation in crosslinking chemistry and application windows.

What Governs Filler Acceptance in Carpet Pre-Coat Formulations Using DA-310?

Carpet pre-coat compound based on DA-310 is formulated with ground calcium carbonate (GCC, top cut 20 µm, 60% passing 10 µm) at loadings of 400–450 parts per hundred resin (phr) without paste gelation, an increase of 50–70 phr compared to non-carboxylated VAE grades when exposed to the same water quality (300 ppm CaCO₃ hardness). The carboxylated particle surface provides additional electrostatic stabilization against Ca²⁺ ions leached from the filler under the slightly alkaline pH (7.5–8.5) generated by the dispersant package. A typical compound recipe includes 100 phr DA-310, 420 phr GCC, 3 phr sodium polyacrylate dispersant, 0.5 phr polyacrylate thickener, and 0.3% silicone-free defoamer on total weight. High-shear viscosity measured via cone-plate rheometry at 10,000 s⁻¹ and 35°C is maintained below 250 mPa·s to prevent misting on a two-roll pre-coat applicator running at line speeds of 25–40 m/min. The shear-thinning index (ratio of Brookfield viscosity at 5 rpm to 50 rpm) lies between 3 and 5, ensuring sufficient body for fiber penetration into the primary backing yet adequate flow under the doctor roll. Recirculation stability through the pan over an 8-hour shift yields a viscosity drift of less than 20%, and mechanical stability per ASTM D4317 exceeds 2000 rpm without coagulum.

Tuft-lock performance is evaluated according to ASTM D3161 simulated wind uplift; a minimum failure load of 23 kg per tuft row after 24-hour oven aging at 60°C is required for Class I installations. DA-310 compounded with 5 phr of a hydrocarbon tackifier dispersion achieves 26–28 kg, while many acrylic copolymer emulsions fall below 20 kg at equivalent filler loads due to insufficient cohesion. After a 10-minute cure at 150°C in a tenter dryer, the film remains flexible with no cracking when subjected to a 1.5 cm mandrel bend at -10°C (EN 1399). Because DA-310 lacks self-crosslinking, it is not recommended for carpet installed over radiant heating where continuous service temperature exceeds 60°C; under those conditions a crosslinkable VAE or polyurethane dispersion should be selected. Unlike styrene-butadiene latex, DA-310 requires no sulfur vulcanization, eliminating odor and sulfidic staining on light-colored face fibers.

In interior flat and satin wall paints formulated above critical pigment volume concentration (CPVC), partial substitution of vinyl acetate-acrylic binder solids with DA-310 at 10–20% of total binder improves scrub resistance under ASTM D2486 from 400 cycles to over 600 cycles on a 175-µm wet film drawdown cured for 7 days at 23°C/50% RH. The ethylene segments behave as internal plasticizers, maintaining film coherence during cyclic wet abrasion. The 0°C MFFT permits coalescence without addition of high-boiling solvents at application temperatures above 10°C, enabling compliance with EU Decopaint Directive 2004/42/EC subcategory A/a (limit 30 g/L VOC). Pigment binding capacity tested per ISO 11998 on a 60% PVC formula yields a wet-scrub loss of <20 mg/100 cycles, superior to polyvinyl acetate homopolymer emulsions which typically reach 30 mg under identical conditions. Contrast ratio measured per ISO 6504-3 at 120 µm wet thickness exceeds 98% with 20% TiO₂ (rutile) on total paint. Despite these wet-state advantages, QUV-B accelerated weathering (ASTM G154 Cycle 1) of a DA-310 bound film registers a color difference ΔE> 5 after 500 hours, confirming that exterior durability is insufficient; use is restricted to indoor environments. In comparison to higher-Tg Dairen grades such as DA-101 (7°C MFFT), DA-310 sacrifices some block resistance but gains low-temperature touch-up performance, making it preferred for renovation paints applied in unheated spaces.

Controlling Wet Tack and Open Time in High-Speed Paper Lamination

Slot-die application of DA-310-based laminating adhesives onto clay-coated folding boxboard requires dilution with 10–15% water to achieve a Brookfield viscosity of 800–1200 mPa·s at the die shear rate of approximately 5000 s⁻¹, preventing ribbing and air entrapment. Wet tack development measured by a Texture Analyser TA‑52 cylindrical probe (ASTM D2979) reaches 2.5 N/25mm within 5 seconds after the laminating nip, matching the performance of high-solids dextrin adhesives while providing superior water resistance after film maturation. Laminated board tensile energy absorption in the cross direction, determined per ISO 1924-2 after 24-hour conditioning at 23°C/50% RH, is 25 J/m², sufficient for high-gloss gift box wrapping without edge lift. The anionic charge of DA-310 avoids precipitation with anionic optical brighteners present in the paper coating, preserving print uniformity on the reverse side. In spiral tube winding, the open time of 20–40 seconds at 25°C/65% RH allows repositioning before the laminate enters the conduction curing drum at 120°C. However, heat seal strength above 80°C is inferior to that of ethylene‑acrylic acid dispersions; consequently, DA-310 is not recommended for flexible pouch structures requiring hot‑fill performance.

In air‑laid nonwoven saturation bonding for wipes and absorbent hygiene products, DA-310 is applied at a 12 wt% binder add‑on onto a 50 gsm cellulose web, followed by drying at 150–160°C for 2 minutes in a through‑air drum oven. Dry tensile strength reaches 8 N/50mm (ISO 1924-2), with wet tensile retention of 35–40% when no crosslinker is used. The absence of N‑methylol acrylamide limits formaldehyde emissions below 10 ppm per ISO 14184‑1, meeting the Nordic Swan Ecolabel requirements for hygiene articles. When 3% ammonium zirconium carbonate (AZC) on binder solids is post‑added, wet tensile retention rises to 65–70%, though pot life of the catalyzed bath is restricted to 6 hours due to progressive viscosity increase. By comparison, Dairen DA‑142—a self‑crosslinking VAE—achieves 80% wet strength retention under the same conditions but introduces reactive formaldehyde into the production environment. Handle‑O‑Meter stiffness of the DA‑310‑bonded web is 30% lower than that produced with a styrene‑acrylic binder at equal add‑on, making it suitable for topsheet materials where skin contact comfort is critical. The carboxyl‑functional surface also improves dye receptivity, unlike the non‑functional DA‑101 grade.

If DA-310 is to Replace PVAc in Wood Glue Assembly Applications

When DA‑310 is evaluated as a direct substitute for polyvinyl acetate (PVAc) homopolymer in D2 service classification per EN 204, the neat emulsion yields a dry shear strength of 12 MPa on beech (Fagus sylvatica) substrates conditioned at 23°C/50% RH (ISO 6237). Following 4‑hour cold‑water immersion at 23°C, wet shear drops to 2 MPa, below the 4 MPa minimum required for D2. Addition of 5% water‑dispersible polymeric MDI crosslinker raises wet shear to 5 MPa, exceeding the D2 threshold but falling short of D3 requirements (7 MPa). Open assembly time on hard maple at 20°C extends to 12 minutes, which is 4 minutes longer than typical of a PVAc D2 grade; this can facilitate complex joint alignment but increases cycle time in high‑throughput dowel insertion lines. Tannin staining is reduced relative to standard PVAc because the ethylene segments lower the concentration of acetic acid liberated by hydrolysis. The anionic nature of DA‑310 creates incompatibility with lignosulfonate extenders, and radio‑frequency curing times are extended by approximately 20% compared to aliphatic polyurethane adhesives due to a higher dielectric constant of the dried film. For Class D3 and above, a dedicated crosslinkable VAE such as Dairen DA‑204 is recommended, as published data for DA‑310 in higher service classes remain limited.