| HS Code | 643758 |
| Chemical Name | Polyvinyl alcohol |
| Cas Number | 9002-89-5 |
| Appearance | White to slightly yellow granular powder |
| Degree Of Hydrolysis | 86.5 - 89.0 mol% (partially saponified) |
| Degree Of Polymerization | Approximately 500 |
| Viscosity 4 Percent Aqueous Solution At 20c | 20 - 28 mPa·s |
| Ph 4 Percent Aqueous Solution | 5 - 7 |
| Volatile Content | Max 5.0 wt% |
| Ash Content | Max 0.5 wt% |
| Bulk Density | 0.4 - 0.6 g/cm3 |
| Solubility | Soluble in water |
| Particle Size | Fine powder, typical range 150 - 350 μm |
As an accredited GOHSENOL EG-22P factory, we enforce strict quality protocols—every batch undergoes rigorous testing to ensure consistent efficacy and safety standards.
| Packing | GOHSENOL EG-22P is supplied as a white granular powder in 20 kg multilayer paper bags with a polyethylene liner. |
| Container Loading (20′ FCL) | 20′ FCL loading of GOHSENOL EG-22P: 25kg bags on pallets, shrink-wrapped, secured to prevent moisture damage and shifting during transit. |
| Shipping | GOHSENOL EG-22P, a polyvinyl alcohol powder, ships as a non-hazardous material in sealed multi-layer paper or PE-lined bags. Keep dry, avoid moisture and dust generation. Transport in ventilated containers at ambient temperatures, protecting from physical damage and incompatible oxidizers. |
| Storage | Store GOHSENOL EG-22P in its original, tightly sealed container in a cool, dry, well-ventilated area. Protect from moisture, humidity, direct sunlight, and excessive heat. Avoid contact with oxidizing agents. Keep away from ignition sources and foodstuffs. Under proper conditions, the material remains stable for an extended period. |
| Shelf Life | GOHSENOL EG-22P has a typical shelf life of two years when stored in a cool, dry place. |
At 86.5–89.0 mol% hydrolysis and a 4 wt% aqueous viscosity of 20.5–24.5 mPa·s at 20 °C, GOHSENOL EG-22P, a partially hydrolyzed polyvinyl alcohol, functions as a protective colloid in vinyl acetate homopolymer and vinyl acetate–ethylene dispersion polymerization. The residual acetate content of 11.0–13.5 mol% contributes interfacial activity at the monomer–water boundary, while the medium molecular weight maintains sufficient grafted PVOH density to suppress coalescence during the particle nucleation burst. In a conventional semicontinuous reactor, the grade is charged as an 8–12 wt% aqueous stock solution prepared at 85–90 °C for 45–60 min under low-shear agitation; the solution is then cooled to 60–68 °C before vinyl acetate feed begins. The protective colloid addition is typically 3–6 wt% based on total vinyl acetate monomer for homopolymer wood and packaging dispersions. Vinyl acetate–ethylene systems require 5–8 wt% because ethylene pressure suppresses radical mobility and reduces grafting yield at the PVOH backbone. A 316L stainless jacketed reactor equipped with a turbine or pitched-blade impeller operating at 90–150 rpm is the preferred equipment configuration; rotor–stator high-shear devices are not recommended because excessive shear during nucleation can induce irreversible coagulum formation. Thermal initiation with potassium persulfate at 0.05–0.2 wt% on monomer is standard, with sodium metabisulfite at 0.02–0.1 wt% as a redox partner when lower reaction temperature is required. Residual persulfate above 0.25 wt% can crosslink free PVOH in the aqueous phase and cause final emulsion viscosity to drift upward; final viscosity is therefore checked by ISO 2555:2018 at 25 °C, and solids by ISO 3251:2019. Compliance for food-contact adhesive formulations is anchored to FDA 21 CFR 175.105 and, for paperboard laminating adhesives, 21 CFR 176.170; EU shipments require REACH registration and verification of migration limits under EU 10/2011 if the final article contacts food. The downstream production line includes a hold tank, a monomer metering pump, a jacketed reactor, a cooler, and a post-stripping vessel for residual vinyl acetate removal; residual monomer is stripped to below 0.1 wt% with steam or nitrogen, and the emulsion is filtered through a 150–250 µm bag filter. Terminal product types include polyvinyl acetate homopolymer wood assembly adhesives tested under EN 204:2016 D3/D4 classifications, paper tube and case-sealing adhesives, and vinyl acetate–ethylene copolymer latices for coating and lamination binders. Operational boundaries include avoidance of borax or boric acid post-addition above 0.1 wt% dry emulsion, because borate ion complexes with free PVOH and generates an immediate viscosity increase; direct contact with aldehydes or ketones can produce acetal formation and must be excluded from storage tanks and transfer lines.
Spun cotton and polyester/cotton warp sizing lines consume GOHSENOL EG-22P as the continuous film former in size-box formulations; the grade is introduced at 6–10 wt% of total size liquor, with oxidized starch at 3–6 wt%, acrylic size at 1–3 wt%, and wax below 0.5 wt% to prevent film delamination at the split rod. Dry size add-on on warp yarn is maintained at 8–14% owf, with the lower end used for high-twist fine-count yarns and the upper end for coarse open-end yarns on air-jet looms. The cooked size is prepared in a continuous jet cooker at 120–135 °C with residence time of 15–25 s; after dilution, the size box temperature is held at 75–85 °C. If the size box falls below 65 °C, partially hydrolyzed PVOH can form a surface skin on the rollers, which breaks into small flakes and deposits on the warp sheet, producing weaver-visible size droplets and loopy warp breaks. Multi-cylinder slasher drying uses wet splitting after the first two cylinders; cylinder surface temperatures are set from 110–125 °C in the pre-dry zone to 85–100 °C in the final zone, achieving 7–10% equilibrium moisture in the sized warp. The sized yarn is then transferred to high-speed sectional or direct warping and weaving; loom efficiency is evaluated against warp stops per 100,000 picks, and film toughness is measured by elongation at break of a cast film under ISO 527-2:2012 or an equivalent in-house method. Compliance for the finishing mill rests on desizing effluent control and restricted substance declarations: ZDHC MRSL v3.1 limits apply to APEOs, chlorinated solvents, and residual monomers, while OEKO-TEX Standard 100 Annex 6 certifies residual chemical levels on finished fabric. Terminal product types include shirting, workwear, bed linen, and curtain fabrics where the size is removed in a subsequent enzymatic or oxidative desizing bath, typically with α-amylase at 60–70 °C for 15–30 min.
When GOHSENOL EG-22P is introduced into the surface-size stream of a fine paper machine running at 900–1,400 m/min, the dominant operational constraint is film splitting at the film-press nip rather than bulk solution viscosity. The grade is metered as a 5–10 wt% pre-dissolved solution into the starch stream to achieve 0.5–2.0 wt% PVOH solids based on total surface-size solution; cooked starch solids are maintained at 8–12 wt%. At these addition levels, the PVOH increases the extensional viscosity of the splitting film, improves starch film cohesion, and reduces binder migration into the base sheet. Film-press application temperatures are held at 60–80 °C; below 55 °C, partially hydrolyzed PVOH can deposit a gel layer on the metering rod and cause streaking. After the film press, the web passes through infrared or air-float dryers and cylinder sections to a final moisture content of 4–6% before calendering. Surface-size quality is validated by ISO 535:2023 Cobb water absorption, ISO 8791-2:2013 Parker Print Surf roughness, and IGT pick strength measured under ISO 3783:2006. For food-contact grades, the finished paper and board must comply with FDA 21 CFR 176.170 and 176.180, supported by migration testing under EU 1935/2004/EC and applicable national BfR recommendations; the PVOH component is not considered a plasticizer or surfactant and must be listed in the supplier formulation disclosure. Terminal product types include woodfree printing papers, release liner base, folding boxboard, and coated base papers where the surface treatment must balance ink holdout and water-based adhesive receptivity.
GOHSENOL EG-22P is formulated into remoistenable adhesive coatings at 25–35 wt% solids; glycerol or sorbitol is added at 2–5 wt% of PVOH solids to lower dry film brittleness, and a non-silicone wetting agent is used at 0.05–0.2 wt% to prevent cratering on clay-coated envelope stocks. The adhesive is applied by reverse gravure or Meyer rod to flap paper at a dry coat weight of 5–12 g/m². Drying tunnel air temperatures are set at 80–120 °C, while web surface temperature is held below 95 °C; if the web exceeds 105 °C, residual moisture falls below 2% and the gum becomes non-uniformly remoistenable. Blocking resistance of the coated stack is assessed under ASTM D918-16 at 40 °C and 65% RH; separation must occur without fiber tear, and the remoistened bond must develop initial tack within 5–10 s after water application. Compliance for envelope adhesives intended for food-contact packaging is established under FDA 21 CFR 175.105 and EU 1935/2004/EC, with REACH registration for the polymer and plasticizer. Terminal product types include remoistenable envelope flaps, postage stamp backing, paper label gummings, and paper splicing tapes used in continuous web converting.
In dry-pressed technical ceramic granulates, the temporary organic phase controls green density, ejection integrity, and binder burnout crack density. GOHSENOL EG-22P is introduced as a 5–10 wt% aqueous solution into an alumina or zirconia slurry at 1.0–2.5 wt% PVOH solids on ceramic powder; the grade is typically combined with a polyacrylate dispersant and polyglycol plasticizer during ball-mill mixing or high-shear dissolver preparation. The slurry is spray-dried at inlet temperatures of 200–260 °C and outlet temperatures of 90–120 °C to produce free-flowing granules with 0.5–1.5% residual moisture. Pressing operations use uniaxial presses at 40–120 MPa or cold isostatic presses at 150–250 MPa; ejection strength is partially controlled by the PVOH glass transition and the moisture content of the granulate. Binder burnout is conducted in air or nitrogen/air cascading kilns with a plateau at 450–600 °C for 1–4 h; heating rates through the 250–400 °C decomposition window should not exceed 1–2 °C/min to avoid delamination. Published quantitative data for this specific PVOH grade in all oxide systems is limited, so burn-out profiles must be confirmed by TGA/DSC under the intended kiln atmosphere. Green body strength may be measured by ASTM C1424-15; ceramic producers also require ISO 9001:2015 process control and REACH-compliant binder documentation. Terminal product types include alumina electronic substrates, zirconia structural parts, and other oxide-based technical ceramics where temporary binder cleanliness and ash content below 0.5 wt% are critical.
Cementitious patching compound dry mixes exhibit measurable set retardation when GOHSENOL EG-22P is included above 0.8 wt% of total dry mixture. The normal addition window is 0.2–0.8 wt%, which improves wet adhesion and reduces surface crusting without excessively delaying the Vicat initial set; above 0.8 wt%, the partially hydrolyzed PVOH accumulates at the hydration layer of tricalcium silicate and can extend initial set beyond 240 min under EN 196-3:2016. In dry-mix production, EG-22P powder is blended in a twin-shaft paddle mixer with cement, graded silica sand, and cellulose ether for 120–180 s; the material is then packed in moisture-resistant bags because PVOH absorbs atmospheric moisture above 60% RH and can form lumps in storage. Site mixing uses 0.18–0.22 water-to-solid ratio; application is by trowel or pump at substrate temperatures from 5–30 °C. Below 5 °C, PVOH film formation is incomplete and the polymer loses its bridging function; above 30 °C, water loss shortens open time and creates dry-out cracks at edges. Compliance for indoor patching and repair mortars refers to EN 998-1:2016 or EN 1504-3:2005 depending on structural repair class, while mechanical testing follows EN 196-1:2016. Terminal product types include non-structural repair mortars, cementitious patching compounds, and self-leveling underlayments for interior flooring preparation.
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GOHSENOL EG-22P is a partially hydrolyzed polyvinyl alcohol powder manufactured under the GOHSENOL product line. The resin carries a nominal hydrolysis range of 86.5–89.0 mol% and an aqueous solution viscosity of 20.5–24.5 mPa·s when measured as a 4% solution at 20°C according to JIS K6726. Because the degree of hydrolysis remains below 90 mol%, residual acetyl groups are present in sufficient quantity to modify aqueous surface activity, foam character, and adhesion to hydrophobic substrates. The grade designation “22P” identifies a medium-viscosity, powder-form PVOH in the EG series; published specification limits for volatile matter, ash, and pH appear in the accompanying table.
| Property | Test condition / method | Specification or typical value |
|---|---|---|
| Appearance | Visual inspection | White to pale-yellow powder or granules |
| Viscosity | 4% aqueous solution, 20°C, JIS K6726 | 20.5–24.5 mPa·s |
| Degree of hydrolysis | JIS K6726 | 86.5–89.0 mol% |
| pH | 4% aqueous solution, 20°C, JIS K6726 | 5.0–7.0 |
| Volatile matter | JIS K6726 | ≤5.0% |
| Ash as Na₂O | JIS K6726 | ≤0.5% |
The combination of medium viscosity and partial hydrolysis places EG-22P between low-viscosity, high-surface-activity grades such as EG-05P and high-viscosity PVOH used for film strength. Its high residual acetate concentration relative to fully hydrolyzed grades lowers the crystalline melting range and reduces gelation of aqueous solutions on cooling. This property supports use in applications requiring stable low-temperature solution behavior and moderate dried-film water solubility.
The first operational boundary in solution preparation is particle wetting and thermal energy input. In closed high-shear dissolution tanks, EG-22P powder is typically dispersed into ambient water at 20–30°C under agitation at 300–500 rpm using a sawtooth dispersing blade; the slurry is then heated to 85–90°C and held for 30–60 min at 1.0–2.0 bar absolute pressure to reduce surface foam. Under these conditions, a 10 wt% solution reaches Brookfield viscosity values approximately 150–400 mPa·s at 60°C as measured with spindle LV 2 at 30 rpm; published data for this specific configuration is limited and should be verified against site-specific mixing power. Direct polymer addition to hot water above 60°C produces a gelatinous outer layer on the particle and is a documented cause of undissolved fisheyes in subsequent coating. In pressure-rated tanks, nitrogen inerting is not required solely for dissolution but may be applied when the solution is held above 80°C for more than 8 h to inhibit oxidative discoloration. The solution should be cooled below 50°C before transferring to storage because prolonged exposure to iron or copper surfaces at elevated temperature can catalyze degradation. At relative humidity above 60%, the powder may absorb moisture and caking occurs; pre-drying at 60°C for 1 h is normally sufficient before feeding to loss-in-weight hoppers.
Polymerisation of vinyl acetate and vinyl acetate–ethylene (VAE) emulsions uses partially hydrolyzed PVOH as protective colloid to control particle nucleation, emulsion viscosity, and mechanical stability. EG-22P is dosed at 2–6 wt% of monomer mass, normally as a 10–12 wt% aqueous solution. The medium solution viscosity of EG-22P produces a higher continuous-phase viscosity than EG-05P at equivalent solids, which can shift the particle size distribution toward coarser particles and increase finished emulsion viscosity. Laboratory-scale reactors of 2 L with anchor agitators at 150–250 rpm produce final VAE emulsions with solids near 55–60%; Brookfield RVT viscosity at 20 rpm and 25°C typically spans 1,000–5,000 mPa·s for grades containing higher PVOH content. In full-scale plants, circulation through an external heat exchanger and half-pipe coil reactors with turbulent flow is used to remove the exotherm; thermal control at 70–80°C is maintained to prevent destabilization. The residual acetyl groups in EG-22P contribute interfacial activity and reduce the need for high levels of nonionic surfactant, although this does not eliminate the need for surfactant in high-ethylene VAE formulations. Published data for this specific grade in high-pressure ethylene polymerisation is limited; formulators generally validate low-pressure vinyl acetate homopolymer and low-ethylene VAE first.
In paper surface sizing and pigmented size-press formulations, GOHSENOL EG-22P is incorporated at 2–8 wt% in 55–65°C aqueous solution. At these concentrations, the 4% solution viscosity of 20.5–24.5 mPa·s translates to runnable size-press viscosity without forcing excessive starch dilution. Cationic starch co-binder ratios of 60:40 to 80:20 starch:PVOH are typical in publication grades; the 86.5–89.0 mol% hydrolysis of EG-22P reduces excessive inter-fiber hydrogen bonding, maintaining sheet caliper after calendering. Cobb values measured according to ISO 535 may be higher than those obtained with fully hydrolyzed PVOH unless a crosslinker such as ammonium zirconium carbonate at 0.5–2.0 wt% of PVOH solids is added. The use of borax or boric acid is contraindicated in size-press formulations above 50°C because pH-sensitive PVOH–borate gelation can form insoluble deposits on rolls and doctor blades. For pigmented coatings, high-shear viscosity response should be checked with a capillary viscometer at 10,000–100,000 s⁻¹; EG-22P contributes more shear stress than low-molecular-weight grades but remains below the level associated with blade-actuated scratches.
Remoistenable adhesive systems rely on dried PVOH films that rehydrate on demand yet retain sufficient cohesion before drying. EG-22P is used at this boundary because its partially hydrolyzed structure dissolves more readily in cold water than fully hydrolyzed PVOH. In aqueous adhesive compounding, 10–25 wt% EG-22P solutions are combined with plasticizers such as glycerol or sorbitol at 5–15 wt% of PVOH solids. Boric acid and borax are commonly used as rheology modifiers at 0.1–1.0 wt%; however, the interaction between borate ions and the hydroxyl groups of PVOH produces a pH-sensitive crosslinked network. If levels exceed 1.0 wt%, the solution may gel above 50°C or at neutral pH, blocking transfer lines. In adhesive formulations where borate is incompatible due to pH control or rewetting requirements, alternative crosslinkers such as glyoxal at 0.05–0.2 wt% of PVOH solids produce a lower degree of irreversible gelation. Adhesive open time is measured on coated paperstock at 23°C and 50% relative humidity; films from EG-22P retain tack for 5–15 s after rewetting, depending on plasticizer type. The film tensile strength is lower than that of fully hydrolyzed PVOH, which must be considered when adhesive bond strength exceeds 2 N/15 mm in peel testing.
Comparison of EG-22P against other GOHSENOL PVOH grades clarifies the practical consequences of viscosity and hydrolysis differences. All EG-series grades in the table share the same partial hydrolysis range; the principal variable is solution viscosity, which correlates with average molecular weight and therefore with film cohesion, emulsion thickening, and dissolution time.
| Grade | Hydrolysis range | 4% viscosity at 20°C | Typical distinction |
|---|---|---|---|
| EG-05P | 86.5–89.0 mol% | 4.8–5.8 mPa·s | Lower solution viscosity, faster dissolution, lower finished emulsion viscosity |
| EG-22P | 86.5–89.0 mol% | 20.5–24.5 mPa·s | Medium viscosity, balance between dispersant activity and film strength |
| EG-30P | 86.5–89.0 mol% | 27.0–33.0 mPa·s | Higher viscosity, increased cohesion, slower cold-water dissolution |
| EG-40P | 86.5–89.0 mol% | 40.0–46.0 mPa·s | Highest EG-series viscosity, more shear stress in coating and adhesive systems |
| Fully hydrolyzed PVOH representative | 98.0–99.0 mol% | 20.0–30.0 mPa·s | Lower cold-water solubility, greater water resistance, higher crystallinity |
The critical difference between EG-22P and fully hydrolyzed PVOH is not solution viscosity but the residual acetyl content. At 86.5–89.0 mol% hydrolysis, EG-22P retains sufficient acetate to weaken interchain hydrogen bonding, lower the crystal melting range, and increase solubility in cold water. This reduces equilibrium water resistance of the dried film unless crosslinked. Fully hydrolyzed grades with 98.0–99.0 mol% hydrolysis form denser, more crystalline films and are preferred where low water solubility is required. In paper applications, EG-22P tends to generate more stable size-press rheology but higher Cobb values than fully hydrolyzed PVOH at equal coat weight.
In suspension polymerisation of vinyl chloride, GOHSENOL EG-22P functions as a secondary dispersing agent when combined with lower hydrolysis PVOH grades. The medium viscosity modifies interfacial tension and PVC grain porosity. Typical addition levels of 0.1–0.4 wt% on monomer are used in stainless-steel autoclaves at 50–65°C with peroxide initiators. The effect on grain morphology is monitored by sieve retention at 45 µm and 250 µm and by apparent bulk density measured according to ISO 60. Published data for this specific grade in vinyl chloride suspension polymerisation is limited; the addition level must be optimized against reactor fouling rate and plasticizer absorption of the dried PVC.
Bulk handling of EG-22P in silos requires dry air purging when ambient relative humidity exceeds 60%. The powder has a bulk density typically between 0.40–0.60 g/cm³ depending on particle size distribution and compaction; published data for this specific grade is limited. Conveyors should be sized for cohesive flow and equipped with hopper vibrators to avoid bridging. Absorption of moisture from air can increase the measured volatile content above the 5.0% specification limit and alter screw feeding accuracy on loss-in-weight systems. Dissolution plants may use eductor systems where powder is wetted by a water jet at 15–25°C before entering a high-shear mix tank; if the water temperature exceeds 30°C, lump formation increases. Long-term solution storage beyond 72 h at 40°C can promote microbial growth because diluted PVOH is biodegradable; a biocide compatible with nonionic or weakly anionic systems is required. The material is not compatible with concentrated strong acids or strong alkalis above pH 10 because chain scission and hydrolysis can occur. Aqueous solutions should not be exposed to copper, copper alloys, or unprotected iron surfaces at temperatures above 70°C because transition metal ions accelerate oxidative degradation.
