Emulsão Dairen DA-117 VAE

Dairen DA-117 is a vinyl acetate-ethylene (VAE) copolymer emulsion produced via a high-pressure continuous emulsion polymerization process. The product carries a solids content of 55.0 ± 1.0 wt% (ISO 3251:2019, 105 °C, 3 h), a Brookfield LVF viscosity of 1800–3200 mPa·s at 20 rpm and 25 °C (spindle 4), and a pH of 4.2–5.2 (ISO 976:2013). The ethylene content, elevated relative to conventional VAE binders, depresses the minimum film-forming temperature (MFFT) to ≤0 °C without external plasticizers, while the glass transition temperature (Tg) measured by differential scanning calorimetry (DSC, 10 °C/min) remains near −12 °C. These features position DA-117 as a soft, permanently tacky binder where compliance with REACH, FDA 21 CFR 175.105 (indirect food contact adhesives), and AOX-free status are prerequisite. The following sections map its behavior across distinct manufacturing environments, contrasting it with lower-ethylene VAE grades and acrylic dispersions where processing window conflicts or property cliff-edges emerge.

Adhesion to untreated polypropylene under high-speed lamination — what changes when ethylene content crosses 18 mol%?

Lamination of corona-treated polypropylene (PP) film to paperboard at line speeds exceeding 120 m/min exposes a critical dependence on the emulsion’s surface energy contribution. DA-117, with an estimated ethylene co-monomer content exceeding 18 mol%, yields a surface energy of 38–42 mN/m in the dried film (Owens-Wendt method, based on contact angle measurements with water and diiodomethane). In pilot trials on a Nordmeccanica Super Combi 3000 laminator, an adhesive coat weight of 2.2 g/m² (dry) achieved a 180° peel strength of 2.8–3.4 N/15mm (ASTM D903-98, withdrawal rate 300 mm/min) on PP substrates with a dyne level as low as 36 mN/m. By comparison, a lower-ethylene VAE (DA-101, approx. 12 mol% ethylene) required a minimum substrate dyne level of 40 mN/m to maintain cohesive failure within the paper substrate, otherwise adhesive transfer to PP dropped below 1.2 N/15mm. The operational boundary for DA-117 is the rheological profile: at shear rates simulating a slot-die coating head (10⁴ s⁻¹), viscosity drops to 80–120 mPa·s (capillary rheometer, 40 °C), which can cause ribbing instabilities if the gap is not maintained within 0.15 ± 0.02 mm. Pre-drying of the web to <0.3% moisture content is mandatory; residual moisture above 0.5% triggers micro-foaming at the nip, reducing immediate green bond to <50% of the target value. The emulsion must be stored above 5 °C and below 40 °C — freeze-thaw cycling produces grit>200 µm (ISO 4576, wet sieve), leading to streak defects on gravure cylinders.

In another domain, the material’s incorporation into cementitious waterproofing slurries diverges sharply from typical acrylate behavior. When DA-117 is dosed at 8–12 wt% on cement weight (OPC 42.5R), the latex films in the capillary pores and reduces water absorption under hydrostatic pressure to <4% after 48 h (DIN EN 12390-8:2019). However, a processing conflict arises: the anionic stabilization system in DA-117 is sensitive to divalent cations released during early cement hydration. If the slurry is mixed in high-shear dispersers (e.g., Collomix, 800 rpm) for periods exceeding 180 s, the abrupt temperature rise above 35 °C can shear-destabilize the latex, forming micro-coagulum that reduces flexural strength by 18–22% (ISO 178:2019). This is a cliff-edge — mixing times below 120 s preserve a homogeneous co-matrix. PCE-based superplasticizers at dosages>0.3 wt% (on cement) can also compete for adsorption at the latex particle surface, necessitating a compatibility pre-test using a mini-slump cone (ASTM C143/C143M). The air-entraining effect of DA-117, typically introducing 5–8% additional entrained air in a fresh mortar, can be beneficial for freeze-thaw resistance (ASTM C666/C666M, procedure A) but must be countered with a silicone defoamer if compressive strength falls below 25 MPa.

Nonwoven interlining: balancing block resistance at 60 °C with dry cleaning durability

In the manufacture of polyester nonwoven interlinings for garment reinforcement, DA-117 is applied by foam impregnation or kiss-roll coating. The soft polymer backbone ensures that after curing at 130 °C for 90 s in a belt dryer, the binder does not suppress hand feel — a drape stiffness increase of <15% (ASTM D4032-08, circular bend) over the unbonded web. Where it differs markedly from acrylic binders (e.g., a styrene-acrylic with Tg −5 °C) is in response to perchloroethylene dry cleaning. After 5 cycles per ISO 3175-2:2020, DA-117-bonded interlinings retain >92% of their initial peel strength (ASTM D2724), whereas acrylic alternates often drop below 70% due to ester group swelling in the solvent. A notable limitation appears in block resistance at elevated storage temperatures: rolls of interlining coated with DA-117 and stored at >50 °C under compression develop slight surface tack within 48 h. To avoid this, a top-coat of a harder VAE or a fugitive anti-block agent must be applied when the storage climate exceeds 35 °C. Batch-to-batch variance in the emulsion’s particle size distribution, measured by laser diffraction (ISO 13320:2020) to be d50 = 0.45–0.65 µm, can shift foam density in air-stabilized froths by ±8%, requiring inline foam density monitoring (e.g., automatic pycnometer on the foam line) to keep add-on within 12 ± 0.5 g/m².

A technical distinction from the higher-viscosity grade DA-142 (viscosity 4000–6000 mPa·s) manifests in wet-on-wet lamination processes. The lower rheology modifier demand of DA-117 permits a thickener level of 0.15–0.25 phr of an associative polyurethane (HEUR) thickener to achieve a coating viscosity of 2500 mPa·s at 1 s⁻¹, versus 0.4–0.5 phr for DA-142, reducing raw material cost and the risk of water sensitivity from excess thickener. However, the high ethylene content retards the development of the fully coalesced polymer network under low-energy drying conditions: infrared spectroscopy of films dried at 15 °C and 40% RH indicates that 72 h are needed to approach asymptotic tensile strength, compared to 48 h for a VAE with 14 mol% ethylene (DA-101). This characteristic must be factored into quality control schedules for products shipped in cold climates.

Beyond laminating and construction, DA-117 finds a specialised niche in the formulation of pressure-sensitive adhesives (PSAs) for removable labels and protective films. Unlike solution polymerised acrylic PSAs that require solvent recovery, DA-117 can be tackified in aqueous dispersion with a rosin ester dispersion (e.g., softening point 85 °C) at a resin-to-polymer ratio of 15:100 to 25:100 (parts dry). The resulting dry film, coated at 25 g/m² on silicone release liner, exhibits a loop tack of 4.5–6.5 N/25mm (ASTM D6195-03) on stainless steel and a 24 h dwell peel of 3.8–5.2 N/25mm from glass. What constrains this application is the amphiphilic nature of the polymer: after 72 h exposure to 85% RH and 38 °C, peel strength on low-energy polyethylene surfaces can increase by 25–35% as the film absorbs moisture, a phenomenon documented via dynamic mechanical analysis showing a secondary relaxation peak near −50 °C. Thus, removable PSA labels intended for humid environments require a protective overlaminate or a reformulation with a hydrophobic monomer-modified VAE to remain within the 2–4 N/25mm removal window. Published data for long- term UV aging (> 1000 h QUV, ASTM G154 cycle 1) of DA-117-based PSA films is limited, but preliminary tests indicate a yellowing index increase of ΔYI <3 when formulated with a hindered amine light stabilizer (HALS) at 0.3 phr.

When a textile pigment printing binder must survive industrial laundering at 85 °C

In all-aqueous pigment printing pastes for cotton/polyester workwear, DA-117 is letdown into a print paste at 12 wt% binder (dry on paste). After screen printing through a 120 mesh (thread diameter 55 µm) and curing at 150 °C for 3 min in a hot air stenter, the print’s wet crock fastness reaches grade 3–4 (ISO 105-X12:2016) and dry crock grade 4. The soft polymer film permits the fabric to remain compliant with EN 14362-1:2017 for aniline emissions, as no aromatic amines are introduced. The key differentiator from a standard self-crosslinking acrylic is the absence of formaldehyde-releasing crosslinkers such as N-methylolacrylamide; DA-117 achieves its cohesion through the high molecular weight of the VAE backbone and interparticle chain entanglement upon coalescence. However, the trade-off appears under severe alkaline hydrolysis conditions: when subjected to 50 wash cycles at 85 °C with a detergent containing 2 g/L of sodium metasilicate, print delamination onset is noted after 35 cycles, whereas a crosslinked acrylic retains>80% print intactness through 50 cycles. For this reason, DA-117 is recommended for workwear where the primary cleaning protocol is hot-water (60 °C) laundering per ISO 15797:2017, not for industrial alkaline cooking washes. The binder also exhibits pronounced foaming under high-speed rotary mixing (> 1500 rpm), requiring a deaerator addition of 0.05–0.1 wt% of a polysiloxane defoamer before pigment slurry incorporation.

In wood adhesive applications, DA-117 competes with polyvinyl acetate (PVAc) homopolymer emulsions in furniture assembly. The PVAc’s higher Tg (24–28 °C) provides superior heat resistance (often up to 70 °C before creep failure in EN 12765:2016 bond strength tests), whereas DA-117 softens significantly above 50 °C, limiting its use to interior joints not subjected to sustained load at elevated temperatures. Yet on high-oil tropical woods like teak (moisture content 12–14%, oil content 3–5%), DA-117 delivers a dry bond shear strength of 6.5 MPa (ISO 6238:2018) versus 3.8 MPa for a standard PVAc, attributed to the ethylene segments’ affinity for non-polar extractives. Manufacturers often blend DA-117 with a crosslinking isocyanate dispersion at 5–10 phr to push the heat resistance towards 65 °C, though this introduces a pot life of <2 h and must be monitored via gel time at 25 °C. During this blending, humidity levels above 60% RH accelerate isocyanate deactivation by water, making moisture-controlled dosing apparatus indispensable.

Frequently, the most critical operational boundary is the interaction of DA-117 with polyvalent metal salts in compound formulations. Addition of zinc stearate powder (0.5–1.0 phr) in a carpet backing formulation can reduce tack but at the expense of a measurable particle size increase in the liquid compound after 24 h aging — from d50 = 0.55 µm to 0.85 µm — indicating incipient destabilization. Therefore, any such additive must be post-added as a pre-dispersed paste, never dry, and the compound used within 8 h. The emulsion is supplied with a shelf life of 6 months from date of manufacture when stored in unopened containers at 5–35 °C, and a biocidal package ensures a bacterial count of <100 CFU/mL (ISO 21149:2017) throughout this period.