Celvolit 1319 VAE Emulsão

Celvolit 1319 is a surfactant-stabilized, water-based vinyl acetate-ethylene (VAE) copolymer dispersion manufactured by Celanese. The product is supplied as a free‑flowing, milky‑white liquid with a solids content determined by ISO 3251 of 54–56 % by mass. Under standard shear conditions (Brookfield RVT, spindle 4, 20 rpm, 23 °C), the dynamic viscosity falls in the range 1 000–3 000 mPa·s as measured per ISO 2555. The pH (ISO 976) is maintained between 4.0 and 5.0, imparting an anionic character compatible with a broad range of formulation adjuncts. Minimum film‑forming temperature (MFFT) determined according to ISO 2115 is typically 0 °C, eliminating the need for external coalescing agents under most ambient application conditions. The dispersion contains no alkylphenol ethoxylate (APEO) surfactants, no intentionally added formaldehyde or formaldehyde‑releasing agents, and complies with the chemical restrictions of EU Ecolabel and Nordic Swan criteria for indoor paints and adhesives.

How do the built‑in cohesion and plasticizer‑free flexibility of Celvolit 1319 influence D3 wood adhesive durability?

In D3 interior wood assembly adhesives tested under EN 204, the primary performance demand is retention of bond strength after 4 h immersion in cold water. Celvolit 1319, with an ethylene comonomer content between 10 and 15 % by weight of the polymer backbone, provides permanent internal plasticization that reduces the glass‑transition temperature to approximately −15 °C. This low‑T_g architecture avoids the migration and eventual embrittlement observed with monomeric plasticizers such as dibutyl phthalate or benzoate esters. In a standard beech‑block D3 test assembly (glue spread 150 g/m² double‑side, open time 8–10 min at 23 °C/50 % RH, cold press 0.7 N/mm² for 30 min), the neat dispersion yields wet tensile strengths consistently exceeding 2.0 N/mm² after the 4‑h soak, provided the wood moisture content is controlled between 8 and 12 % prior to gluing. For applications requiring D4 durability (boil‑resistant), a post‑addition of a water‑dispersible polymeric isocyanate crosslinker at 5–10 % by weight of the dispersion is common. The pot‑life of such a two‑component system at 23 °C is limited to 90–120 min; batch sizes must therefore be matched to throughput on panel‑press lines with throughput capacities below 500 panels/h. On a Becker‑van Hüllen short‑cycle press with a platen temperature of 80 °C and a press time of 120 s, the crosslinked adhesive achieves D4 pass criteria with a 24‑h cold‑soak wet tensile strength above 4.0 N/mm² and a delamination rate below 5 % on three‑ply spruce laminations. Formulators should note that the isocyanate reacts preferentially with water; therefore, pre‑mixing must be conducted under controlled relative humidity (≤60 %) and the mixed adhesive must be used before a Brookfield viscosity increase of 30 % is observed.

Long‑open‑time packaging adhesives and hot‑tack development

Polymer‑dispersed paper and packaging laminations require a balance between extended open time on high‑speed roll‑coating lines and rapid hot‑tack formation under heated nip pressure. Celvolit 1319, owing to its small average particle diameter of approximately 1.5 µm (laser diffraction, ISO 13320) and a unimodal size distribution, deposits uniformly on cellulose substrates without excessive penetration into the sheet. On a Bachofen‑type three‑roll coating station running at 80 m/min with a gravure cylinder of 45 lines/cm, a wet film weight of 12–15 g/m² is achieved without misting. The low MFFT and high wet‑tack plateau of 0.6–0.8 N/25 mm (as determined by a Texture Analyser using a 25 mm probe, compression 2 N for 5 s) enable the adhesive to hold polyethylene‑coated board in place within 2 s of nip closure at 70 °C. Compared with homopolymer poly(vinyl acetate) dispersions of equivalent solids, Celvolit 1319 exhibits a lower heat‑seal activation temperature—the temperature at which cohesive strength reaches 1.0 N/25 mm is reduced by approximately 10–12 °C. This is attributable to the ethylene segments facilitating chain entanglement under mild thermal activation. The consequence is a broader processing window on blister‑pack sealing machines (e.g., Uhlmann BEC 300), where dwell times can be shortened from 1.5 s to 0.8 s without sacrificing seal integrity. It should be noted that prolonged exposure of the wet adhesive film to ambient conditions (open time> 30 min at 25 °C/45 % RH) leads to a measurable drop in hot‑tack due to skinning; line speed adjustments are necessary when intermittent stops exceed 15 min. Incorporation into cementitious tile adhesives (C2TE classification per EN 12004) requires careful attention to the dispersion’s anionic charge and its interaction with high‑pH, calcium‑rich slurries. Celvolit 1319 is typically added at 3–7 % on cement weight to a dry‑mix composed of CEM I 42.5 R, silica sand (0.1–0.5 mm), and cellulose ether (0.3–0.5 %). The polymer particles coalesce during the drying phase and form a continuous network that improves tensile adhesion strength after water immersion, fulfilling the ≥ 0.5 N/mm² requirement stipulated by EN 12004 for C2 adhesives. However, alkalinity‑induced saponification of the acetate groups is a known degradation pathway; long‑term wet‑storage tests (EN 1348) reveal that tensile adhesion values can decline by 15–20 % after 28 days under permanent immersion at 23 °C if the formulation pH exceeds 12.5. Buffering the mortar with a pozzolanic additive such as metakaolin (5 % of cement weight) helps maintain pH below 12.2 and preserves wet adhesion above 1.0 N/mm² after 28‑day immersion.

Typical specification data for Celvolit 1319 VAE emulsion

Property	Value	Test method
Solids content	54–56 %	ISO 3251
pH	4.0–5.0	ISO 976
Brookfield viscosity (RVT, spindle 4/20 rpm, 23 °C)	1 000–3 000 mPa·s	ISO 2555
Minimum film‑forming temperature	0 °C	ISO 2115
Density at 20 °C	~1.07 g/cm³	ISO 2811-1
Particle size (d50)	~1.5 µm	ISO 13320
Residual monomer (vinyl acetate)	<0.1 %	GC headspace method
Emulsifier system	APEO‑free, anionic/non‑ionic	—

When formulating low‑emission interior wall primers, what role does the absence of coalescing agents play?

Interior primer formulations governed by AgBB or CDPH Standard Method v1.2 impose strict TVOC limits of 100 µg/m³ after 28 days in emission test chambers (ISO 16000‑9). Because Celvolit 1319 has an MFFT of 0 °C, coalescing solvents such as texanol, butyl glycol, or dipropylene glycol n‑butyl ether can be entirely omitted down to application temperatures of 5 °C. In a model formulation containing 25 % pigment volume concentration of titanium dioxide (rutile, 0.3 µm), 40 % Celvolit 1319 on total formulation weight, and calcium carbonate filler, the total volatile organic content (TVOC) as determined by ISO 11890‑2 is below 1 g/L. The wet scrub resistance (ISO 11998) after 200 cycles shows a film loss of <5 µm, indicating sufficient film integrity without the need for supplementary film‑forming aids. Nevertheless, the absence of coalescent presents a risk of crack formation when applied at high wet‑film thicknesses exceeding 300 µm under forced drying at 40 °C and 15 % RH. Under these conditions, surface skinning occurs within 3 min, and microscopic film contractions appear as mud‑cracking. Recommended maximum wet‑film build is 250 µm per coat, with a minimum inter‑coat interval of 4 h at 23 °C/50 % RH. Airless spray application through a 0.015 inch tip at 120 bar yields acceptable spray patterns without cobwebbing, provided the emulsion has been diluted with 5–8 % water by weight to lower the high‑shear viscosity to 100–150 mPa·s (cone‑and‑plate, 10 000 s⁻¹).

Contrast with adjacent Celanese VAE and PVAc grades

Grade	Chemistry	Ethylene content	MFFT (°C)	Typical use emphasis
Celvolit 1319	VAE, APEO‑free	10–15 %	0	Balanced cohesion/flexibility for D3 wood, packaging, cement
Celvolit 1350	VAE, APEO‑free	~18 %	<−3	Very high flexibility, low‑temperature adhesive, high wet tack
Celvolit 1325	VAE, carboxylated	~13 %	0	Improved adhesion to metals, alkali‑resistance in cementitious coatings
Celvolit 203	PVAc homopolymer	0 %	+18	High stiffness, D2 wood, requires plasticizer for flexible films

Differences between Celvolit 1319 and a higher‑ethylene analogue such as Celvolit 1350 become evident in tensile testing (ISO 527‑3, film dried 7 days at 23 °C/50 % RH). The 1319 film exhibits a tensile strength of 4–5 MPa and an elongation at break of 300–400 %, while Celvolit 1350 with its greater ethylene content drops to a tensile strength of 2–3 MPa but extends to 600–700 % elongation. For joint‑sealing tapes or textile laminates requiring high deformation without cohesive failure, the higher‑ethylene grade is preferred; for load‑bearing wood bonds where dimensional stability under creep is critical, Celvolit 1319 provides superior resistance to time‑dependent shear deformation. Operational boundaries must be rigorously observed during storage and handling. The dispersion must be protected from freezing; if frozen and then thawed, irreversible coagulation and a rise in screen residue (retained on a 40 µm filter) above 1 % are expected. Storage temperature should be kept between 5 °C and 30 °C. Pump transfer should employ low‑shear equipment—progressive cavity pumps with rotational speeds limited to 200 rpm and stator elastomers compatible with the mildly acidic pH—to avoid shear‑induced grit formation. When used in conjunction with inorganic pigments such as iron oxides, a preliminary compatibility test is advisable: a blend of 90 % dispersion and 10 % pigment paste, stirred for 5 min at 1 000 rpm, should show a viscosity rise no greater than 500 mPa·s and remain free of grain upon draw‑down with a 100 µm applicator. Compliance with FDA 21 CFR §175.105 permits incorporation of Celvolit 1319 in adhesives intended for indirect food contact (packaging of dry foodstuffs), provided the finished adhesive film is separated from the food by a functional barrier. For use in indirect food‑contact paper coatings, migration testing under the relevant simulant (e.g., Tenax® for dry foods, EN 1186‑13) must confirm overall migration below 10 mg/dm². The dispersion also meets the volatile organic compound requirements of the European Decopaint Directive (2004/42/EC) for the “Primers” subcategory (limit 30 g/L VOC for water‑borne products, phase II). Not every ambient‑cure application benefits from Celvolit 1319. When the substrate is a low‑surface‑energy polymer such as untreated polypropylene or polyethylene, a surface treatment to raise the dyne level above 38 mN/m is necessary; the neat dispersion will not wet surfaces with surface energies below this threshold. In contrast, a carboxylated VAE such as Celvolit 1325 may provide marginal adhesion improvement on some metals, but published data for this specific configuration is limited. In pressure‑sensitive adhesive (PSA) constructions where a permanent tack is required, the neat dispersion does not yield sufficiently high probe tack (typically <0.2 N/25 mm) and must be compounded with tackifying resin dispersions (e.g., rosin ester dispersion at 10–20 % on dry polymer). On a pilot coater running a release‑liner PSA transfer process at 15 m/min, a modified formulation containing 15 % tackifier dispersion and 0.5 % associative thickener produced a dry coat weight of 20 g/m² with a loop tack (FINAT FTM 9) of 3.5 N/25 mm, acceptable for removable decal applications. The tackifier-loaded system, however, exhibits a measurable drop in shear adhesion failure temperature (SAFT) from 120 °C (neat) to approximately 80 °C, limiting its use in hot‑fill label scenarios.