| HS Code | 480480 |
| Chemical Base | Polyvinyl acetate (PVAc) copolymer |
| Physical Form | White free-flowing powder |
| Bulk Density | 400-600 g/L |
| Particle Size | 80 mesh pass rate ≥95% |
| Solids Content | 99% |
| Ph Value | 6.0-8.0 (10% dispersion) |
| Minimum Film Forming Temperature | 5°C |
| Glass Transition Temperature | 10-15°C |
| Viscosity | 500-2000 mPa·s (10% solution) |
| Tensile Adhesion Strength | ≥1.0 MPa |
| Elongation At Break | ≥300% |
| Water Resistance | Good (48h water immersion no significant change) |
| Freeze Thaw Stability | Stable after 5 cycles |
| Compatibility | Compatible with cement, gypsum, and common fillers |
| Application Temperature | 5-35°C |
As an accredited PVAc Putty Modifier factory, we enforce strict quality protocols—every batch undergoes rigorous testing to ensure consistent efficacy and safety standards.
| Packing | PVAc Putty Modifier is packaged in 25 kg moisture-proof paper bags with a PE liner. |
| Container Loading (20′ FCL) | 20′ FCL: PVAc Putty Modifier packed in 25kg bags, palletized, secured, ventilated, and shipped as full container load. |
| Shipping | PVAc Putty Modifier is shipped in sealed drums, pails, or IBC totes, depending on volume. It is typically classified as non-hazardous for ground, ocean, and air transport when properly packaged and labeled. Ensure containers are upright, protected from freezing, and kept away from incompatible materials during transit. |
| Storage | Store PVAc Putty Modifier in a cool, dry, well-ventilated area away from direct sunlight, heat, and open flames. Keep containers tightly sealed when not in use to prevent moisture absorption and contamination. Avoid freezing; ideal storage temperature is 5–30°C. Ensure adequate ventilation and follow local regulations for chemical storage. |
| Shelf Life | Shelf life: 12 months from manufacture date when stored sealed, |
Specification sheets for PVAc putty modifiers intended for cementitious skim coats typically report aqueous dispersion parameters rather than dry-powder redispersibility. A production-grade dispersion is controlled at 50±2% solids, pH 4.5–6.0, Brookfield RV viscosity 2,000–6,000 mPa·s at 25°C, and particle size 0.5–3.0 µm. In a high-pH cement matrix, the protective polyvinyl alcohol colloid and the acetate ester group are the two competing stability factors. The modifier is added at 1.0–3.5 wt% of the total wet batch as a 50% solids dispersion; dry-mix putty formulations that avoid liquid dosing use a spray-dried PVAc or vinyl acetate–ethylene powder at 0.8–2.0 wt% of the dry batch. Manufacturing is performed in a vacuum planetary mixer or a single-shaft batch disperser. Dry components—white Portland cement, limestone fines, hydrated lime, cellulose ether, starch ether, and a mineral defoamer—are pre-blended in a horizontal ploughshare mixer, then the dispersion is introduced after the initial water addition to avoid local shock destabilization. The batch is held at 30–40°C and deaerated at -0.08 MPa to -0.09 MPa; temperatures above 45°C trigger premature film formation and produce grit that is visible in troweled skim coats.
Production-scale failure data from single-shaft batch dispersers show that direct injection of PVAc dispersion onto dry cement powder creates gel nuclei that survive low-shear let-down and appear as specks in the finished skim coat. The corrective sequence is: pre-wet the cementitious powder with 70% of the water for 120 s, add PVAc dispersion over 30–60 s while mixing at 20–25 m/s blade tip speed, then add the remaining water under vacuum. This sequence is maintained for batches up to 1,200 L. At add levels above 3.0 wt%, the air content can exceed 8% unless a mineral defoamer is present; the air content is measured by EN 1015-7:1998 or ASTM C185-20. Compliance testing for internal wall putty follows GB/T 23455-2009, while rendering and plastering mortar variants are assessed under EN 998-1:2016. The technical literature records a practical boundary: PVAc homopolymer dispersions are not alkali-insensitive. In contact with saturated calcium hydroxide solution at pH 12.5–13.5, ester cleavage occurs over weeks; formulators therefore keep active cement content below 20 wt% or blend the PVAc with a vinyl acetate–ethylene or acrylate copolymer. Terminal finished products in this segment include interior wall putty, skim coat paste, ceiling patching compound, and re-dispersible ready-mix wall filler.
| Standard / mandate | Scope | Relevant test focus |
|---|---|---|
| GB/T 23455-2009 | Interior wall putty | Workability, drying time, bond strength, water resistance |
| EN 998-1:2016 | Rendering and plastering mortar | Bond, consistency, capillary water absorption |
| REACH Annex XVII entry 46 | Polymer dispersion additives | Restrictions on certain preservative and VOC categories |
Ready-mix joint compounds in drywall finishing are characterized by a conflict between tensile edge bond and low drying shrinkage. PVAc dispersion added at 2.0–6.0 wt% of the total ready-mix formula, or a spray-dried PVAc powder at 1.0–3.0 wt% of the dry powder, raises the cohesive strength at the tape edge. Dosages below 1.2 wt% on total solids in the paste create edge bond failures and paper fiber lifting during sanding; dosages above 6.0 wt% increase linear shrinkage and produce edge cracking in deep fill. The compound is processed in a double-planetary vacuum mixer or a continuous twin-shaft intensive mixer. Dry filler—calcium carbonate, talc, clay, and mica—is dispersed into a pre-thickened water phase containing cellulose ether, starch, preservative, and the PVAc dispersion. Vacuum deaeration at -0.085 MPa to -0.095 MPa is required because PVAc-stabilized air bubbles increase pinholes in the dried tape film. Batch discharge temperature is controlled at 25–36°C; higher temperatures accelerate preservative depletion and reduce open time. The governing specification is ASTM C475/C475M-24, supplemented by ASTM D2369-20 for total solids and ASTM D2202-00(2019) for slump.
The use of PVAc in joint compounds is bounded by wet-sanding characteristics. PVAc homopolymer films re-disperse more readily than styrene-acrylic films when wetted during sanding, but because the acetate backbone softens above 28°C, storage of filled pails above 40°C can lead to viscosity drift and liquid separation. The production failure mode observed in filled pails is not gelation but syneresis caused by colloidal destabilization when surfactant and preservative partition into the continuous phase. The fix in manufacturing is to delay PVAc addition until the filler slurry has cooled below 35°C. Finished types include all-purpose joint compound, taping compound, topping compound, and spray texture compound.
| Process variable | Lower control limit | Upper control limit | Instrument / test basis |
|---|---|---|---|
| PVAc dispersion input on total batch | 2.0 wt% | 6.0 wt% | Gravimetric dosing check |
| Ready-mix compound total solids | 52% | 58% | ASTM D2369-20 |
| Vacuum during planetary mixing | -0.085 MPa | -0.095 MPa | Pressure transducer |
| Batch discharge temperature | 25°C | 36°C | PT100 thermocouple |
In water-based wood repair pastes, polyvinyl acetate dispersion is introduced as the film-forming binder rather than as a rheology-only additive. The dispersion is typically a high-viscosity homopolymer or vinyl acetate–ethylene grade with 50–55% solids, 0.5–2.0 µm particle size, and a glass transition temperature between 28°C and 35°C. The addition ratio ranges from 10–25 wt% of the total paste as liquid dispersion, equivalent to 5–13% polymer solids. Formulating and production are conducted in a vacuum sigma-blade mixer or a double-planetary kneader at final solids above 70%. The filler load consists of wood flour 20–45 wt%, microcrystalline cellulose, calcium carbonate, and fumed silica; the liquid phase contains benzoate ester plasticizer, defoamer, wetting agent, and preservative. The PVAc dispersion is charged only after the filler pre-wetting stage, otherwise high-shear incorporation onto dry wood flour causes localized coagulation and visible grittiness in the applied paste. Compliance for this application is not governed by a single harmonized wood filler standard; where the repaired surface may be used in children’s furniture or toys, migration limits under EN 71-3:2019 apply, and indoor emission screening is often conducted by California CDPH/EHLB Standard Method v1.2. Terminal finished products include water-based wood filler paste, nail-hole filler, grain filler, and repair putty for MDF and prefinished wood panels. Operational boundary: PVAc-based wood fillers are intended for interior, low-moisture repair. They do not meet outdoor wood repair requirements under continuous water exposure unless formulated with a crosslinker or blended with a hydrophobic copolymer dispersion.
Before pigmented decorative plasters are applied to gypsum board or prepared ceilings, the open time and low-shear viscosity of the wet mix are set by the PVAc dispersion level. In this segment, the modifier is used at 0.5–1.5 wt% as a 50% solids dispersion of the total paste; the solid polymer input is modest because the primary film former in many formulas is a styrene-acrylic or vinyl acetate–ethylene latex. Production takes place in a high-speed disperser at 500–700 rpm with a sawtooth blade, followed by low-speed let-down at 150–250 rpm to reduce entrained air. The filler phase is generally ground marble or dolomite powder, quartz flour, or graded calcium carbonate; wetting of the filler surface before PVAc addition is critical for low-shear viscosity stability. Compliance references include EN 15824:2017 for organic-bound interior and exterior plasters and ISO 7783-2:2011 for water-vapour transmission rate. Terminal products are ready-mixed decorative plaster, trowel-on texture paste, and skim design finish. The practical limitation is that PVAc increases surface tack when relative humidity exceeds 70%; wet-room installations are excluded unless the formulation has been tested for wet adhesion after soaking at 23°C for 24 h.
Water-based latex caulks and sealants represent a higher-binder segment for PVAc dispersions. In an interior paintable caulk, PVAc or a vinyl acetate–ethylene dispersion is the continuous binder at 20–35 wt% of total wet formula, with total polymer solids in the can between 10% and 20%. The filler system is medium-particle calcium carbonate or talc at 20–40 wt%; plasticizer loading is 5–15 phr; thickener content is 0.5–2.0 wt%. Manufacturing uses a low-shear paddle mixer or sigma-blade mixer, with powder filler added as a pre-dispersed aqueous slurry to prevent dry agglomeration. Vacuum deaeration at -0.08 MPa removes pinholes that become visible after tooling. The standard governing the finished product is ASTM C834-17 for latex sealing compounds; movement capability is verified under ISO 11600 Class 7.5P where the product is marketed as a joint sealant, and slump is measured by ASTM D2202-00(2019). Terminal types include paintable interior caulk, non-structural water-based sealant, and acoustic caulk. The manufacturing boundary is freeze-thaw stability: PVAc dispersions with minimum film-forming temperature near 10°C require propylene glycol at 1–3 wt% to survive 5 freeze-thaw cycles from -10°C to 23°C; without it, coagulum forms in the pail and the product cannot be tooled.
Concrete surface repair pastes and non-structural patching mortars are a boundary application for PVAc modifiers because the substrate pH and moisture content directly control ester hydrolysis rate. The modifier is dosed at 1.0–3.0 wt% of the total wet mortar as a 50% solids dispersion; above 4.0 wt% the polymer phase tends to entrain air and reduce the compressive strength of a Class R1 or R2 repair mortar under EN 1504-3:2005. The production sequence for a dry mix uses a horizontal ribbon mixer for cement, graded silica sand, limestone filler, cellulose ether, and spray-dried PVAc; for a ready-mix paste, a planetary mixer is used. The critical processing rule is to avoid adding PVAc dispersion directly onto anhydrous colloidal silica or high-alkali cement before water has formed a continuous slurry; the resulting local precipitation produces visible polymer lumps. Compliance is assessed under EN 1504-3:2005 for non-structural classes R1 and R2, but PVAc-only systems are not recommended for classes R3 or R4 structural repair because long-term alkaline hydrolysis can reduce bond cohesion. Terminal product types include concrete fairing coat, surface pore filler, and small-void repair paste. The application limit is explicit: sustained damp exposure or rising damp on the substrate side accelerates ester cleavage, and published data for this specific configuration under continuous immersion is limited.
Gypsum board edge filling lines run a high-solids paste that must dry within seconds under infrared and then pass through a sanding station before stacking. PVAc dispersion at 3–8 wt% of the wet edge paste supplies adhesion to the gypsum core and paper liner while keeping the sanded edge free of fibre lift. The paste is formulated with fine calcium carbonate or talc, cellulose ether, a fast-drying alcohol ester coalescent, and a PVAc dispersion with solids 50–52%. It is applied by calender roll or slot die to the board edge, then dried under infrared panels at 120–180°C surface temperature for 6–20 s. The finished board is evaluated under ASTM C1396/C1396M-17; the edge compound itself is not separately specified, so the manufacturer’s target is defined by line speed, edge hardness, and absence of cracking at the board ends. Terminal products are gypsum wallboard edge filler, butt-end fill compound, and joint stick paste. The operational boundary is that PVAc must not be overdried in the infrared zone; surface skinning above 180°C before core water removal causes bubbles and delamination of the edge paste.
Competitive PVAc Putty Modifier prices that fit your budget—flexible terms and customized quotes for every order.
For samples, pricing, or more information, please contact us at +8615380400285 or mail to sales2@liwei-chem.com.
We will respond to you as soon as possible.
Tel: +8615380400285
Email: sales2@liwei-chem.com
Flexible payment, competitive price, premium service - Inquire now!
PVAc Putty Modifier PVAc-PM-40 is an anionic polyvinyl acetate homopolymer emulsion supplied as a liquid modifier for cementitious and gypsum-based wall putty compounds. The companion grade PVAc-PM-50 carries a higher nominal solids content and is used where water addition must be constrained. Both grades are introduced at 3–5 wt% of dry formulation as a functional binder modification; they do not replace cement, gypsum, or filler fractions. The product is shipped in 200 L HDPE drums, 1,000 L IBC tanks, and bulk road tankers. Batch release parameters are listed below.
| Property | PVAc-PM-40 | PVAc-PM-50 | Test method |
|---|---|---|---|
| Non-volatile content | 40 ± 1 % | 50 ± 1 % | ISO 3251:2019, 105 °C, 2 h |
| Brookfield RVT viscosity | 30,000–50,000 mPa·s | 20,000–40,000 mPa·s | ISO 2555:2018, spindle 4, 20 rpm, 25 °C |
| pH | 4.5–5.5 | 4.0–5.0 | ISO 976:2013 |
| Minimum film-forming temperature | 5 °C | 7 °C | ISO 2115:1996 |
| Particle size D50 | 0.5–1.5 µm | 1.0–2.0 µm | ISO 13320:2020, laser diffraction |
| Density at 25 °C | 1.05–1.10 g/cm³ | 1.08–1.12 g/cm³ | ISO 2811:2016 |
The batch release viscosity is determined on undiluted emulsion at 25 °C after 24 h conditioning. Final application viscosity of the putty is not controlled by modifier viscosity alone; thickener type and filler particle size distribution dominate the 75–90 KU target range measured by ASTM D562-10 Procedure B.
In a production-scale wet-mix comparison, a base formulation containing 65 wt% 300-mesh calcium carbonate, 8 wt% calcined kaolin, 0.4 wt% hydroxyethyl cellulose of 30,000 mPa·s nominal viscosity, and balance water was modified with 4 wt% PVAc-PM-40. Stormer viscosity increased from 62 KU to 78 KU when measured per ASTM D562-10 Procedure B at 25 ± 2 °C. Open time, assessed by trowelling a 1 mm film on unsealed concrete at 25 °C and 60 % RH, extended from 6 min to 12 min. Wet edge retention improved because the polymer film forms at the air-paste interface and slows evaporative moisture loss. The effect is more pronounced in low-shear hand application than in machine spraying, where high-shear viscosity is controlled by the thickener.
At addition levels below 2 wt%, the polymer concentration is insufficient to form continuous film domains after loss of water, and the effect on open time is marginal. Between 3 wt% and 5 wt%, the dried film transitions from discontinuous to continuous polymer domains; this transition corresponds to a measurable increase in surface hardness and a reduction in free pigment dusting. Above 6 wt%, trowel drag and surface tack become objectionable because excess free polymer phase accumulates at the surface. The practical dose window is therefore narrow; production batches should not exceed 5 wt% unless specifically validated on target substrates.
In a production-scale high-shear dissolver with a 350 mm saw-tooth blade, the addition sequence affects air entrainment. When the modifier is added before the filler, foam height increases by 10–15 % and requires vacuum deaeration. When the modifier is post-added after filler dispersion, air entrainment is reduced and filtration time through a 100 µm bag filter is typically 3–5 min faster for a 1,000 kg batch.
Before the modifier is introduced, the thickener hydration step must be completed in the main mixer. Dilute PVAc-PM-40 with an equal mass of water at 20–25 °C; direct injection of undiluted emulsion into an alkaline paste produces local pH shock and forms coarse polymer agglomerates on the wall. In a 1,000 L planetary mixer operating at 40 rpm central stirrer speed, the diluted stream is introduced at 5–10 kg/min while the scraper blade runs. Dispersion is continued for 15–20 min at a tip speed of 12–15 m/s until a Hegman grind gauge reading of 4–5 on a 50 µm scale is obtained. If entrained air appears, a vacuum deaeration step at −0.08 MPa for 10 min is applied. Transfer to storage should use diaphragm or progressive cavity pumps; piston pumps with valve clearances below 250 µm generate mechanical shear and may coagulate the emulsion.
In a controlled comparison on cementitious putty applied to B40 concrete panels and cured for 28 days at 23 °C and 50 % RH, pull-off adhesion per ISO 4624:2016 increased from 0.28 MPa for the unmodified control to 0.52 MPa at 3 wt% PVAc-PM-40 and 0.71 MPa at 5 wt%. At 7 wt%, adhesion remained near 0.70 MPa while surface tack after 24 h cure became measurable with a polyethylene sheet contact test. The non-linear response is attributed to a shift from binder-starved to binder-rich film morphology and is consistent with the behavior of polyvinyl acetate homopolymer emulsions of similar particle size.
A free film cast from the undiluted emulsion and dried at 23 °C and 50 % RH for 7 days exhibits tensile strength in the range of 6–10 MPa and elongation at break of 10–20 % when tested per ISO 527-2:2012. Dry-film hardness measured by ASTM D3363 is typically HB for PVAc-PM-40 versus 2B for vinyl acetate-ethylene dispersion at the same 4 wt% dosage. The film is thermoplastic and softens above 40 °C; continuous service on heated substrates is not recommended. The modifier therefore contributes cohesive strength and adhesion but not high-temperature creep resistance.
Compared with vinyl acetate-ethylene dispersions, the absence of ethylene comonomer gives higher dry-film hardness and block resistance but lower elongation; vinyl acetate-ethylene films at equivalent solids typically show elongation of 50–150 % and tensile strength of 2–5 MPa. Compared with all-acrylic emulsions, PVAc-PM-40 has lower wet adhesion and alkali resistance. Water absorption after 24 h immersion per ISO 62:2008 is reported in the range of 20–40 % by mass for unplasticized PVAc films, while acrylic films of equivalent thickness are typically 5–15 %. Published data for this specific configuration is limited, and comparative evaluation on the intended substrate is required. Redispersible polymer powders avoid liquid water addition but require spray drying energy and do not contribute to open time in the same way.
| Property | PVAc-PM-40 | VAE dispersion | Acrylic dispersion | Redispersible powder |
|---|---|---|---|---|
| Minimum film-forming temperature | 5 °C | 0–2 °C | 0–10 °C | Not applicable after drying |
| Water absorption, 24 h, ISO 62 | 20–40 % | 10–20 % | 5–15 % | 15–30 % |
| Alkali resistance | Moderate; saponification above pH 10 | Good | Good | Good |
| Typical dosage on dry mix | 3–5 wt% | 2–5 wt% | 2–4 wt% | 2–6 wt% |
Certificates of analysis for each batch list non-volatile content per ISO 3251:2019, Brookfield RVT viscosity per ISO 2555:2018, pH per ISO 976:2013, minimum film-forming temperature per ISO 2115:1996, and particle size distribution by laser diffraction per ISO 13320:2020. Regulatory documentation includes classification under EC 1272/2008 and registration under EC 1907/2006 where applicable. The product is not designed for food-contact use and is not evaluated under FDA 21 CFR 175.105. In the Indian market, finished wall putty compounds can be assessed against IS 15477:2019 for water-based putty performance; the modifier itself is not a finished putty and does not carry IS 15477 certification independent of the formulation.
Final putty formulations should be tested according to the intended application standard, including adhesion, water resistance, and abrasion after curing. The modifier is not a substitute for biocide protection in wet-mix putty. High water activity and neutral pH conditions favour microbial growth; a broad-spectrum in-can preservative validated for polyvinyl acetate emulsions is required when stored paste exceeds 7 days at ambient temperature.
The anionic charge of the emulsion is neutralized by cationic polyelectrolytes, quaternary ammonium biocides, and multivalent salts. Avoid combining PVAc-PM-40 with benzalkonium chloride, aluminum sulfate, or calcium chloride at concentrations above 0.1 wt% of total liquid phase; instantaneous coagulation and screen blinding during filtration have been observed on production lines. Do not add the modifier directly to a high-pH calcium hydroxide slurry. Buffer the slurry to pH 8.0–9.5 with citric acid or sodium bicarbonate before introducing the diluted emulsion. The product undergoes gradual saponification at sustained pH above 10; this reduces binding efficiency and releases acetic acid odor.
Store the product in sealed containers at 5–35 °C. Freeze-thaw cycling is not covered by the specification; storage below 5 °C can cause irreversible coagulation. Storage above 35 °C accelerates skin formation and may increase microorganism growth. Under recommended conditions, batch viscosity drift is less than 5 % over 6 months. Before use, filter the emulsion through a 100 µm bag filter if stored beyond 3 months. On absorbent gypsum board, the substrate must be primed with a PVA-compatible sealer; unprimed board pulls water too rapidly and prevents film coalescence, leaving a chalky surface. The minimum substrate temperature for coalescence is 5 °C. Above 40 °C surface temperature, the open film skins before leveling, producing trowel marks and edge craters.
