| HS Code | 251357 |
| Product Name | GOHSENOL EG-40PW |
| Chemical Family | Polyvinyl Alcohol (PVA) |
| Cas Number | 9002-89-5 |
| Appearance | White powder |
| Degree Of Saponification | 86.5 - 89.0 mol% |
| Viscosity 4 Aqueous Solution At 20 C | 38.0 - 42.0 mPa·s |
| Ph 4 Aqueous Solution | 5.0 - 7.0 |
| Ash Content | ≤ 0.7% |
| Volatile Content | ≤ 5.0% |
| Water Solubility | Soluble in water, forming a clear colloidal solution |
As an accredited GOHSENOL EG-40PW factory, we enforce strict quality protocols—every batch undergoes rigorous testing to ensure consistent efficacy and safety standards.
| Packing | GOHSENOL EG-40PW is supplied in 25 kg net multi-layer paper bags with an inner polyethylene liner, ensuring product protection. |
| Container Loading (20′ FCL) | 20′ FCL container loading of GOHSENOL EG-40PW ensures safe, dry transport with proper palletizing and moisture protection. |
| Shipping | GOHSENOL EG-40PW is a polyvinyl alcohol resin supplied as a free-flowing white powder. It is non-hazardous for transport but should be shipped in dry, sealed packaging to prevent moisture absorption and dust generation. Avoid exposure to excessive heat, humidity, and ignition sources during handling and transit. |
| Storage | Store GOHSENOL EG-40PW in a cool, dry, well-ventilated area away from direct sunlight and moisture. Keep containers tightly sealed when not in use, as the material is hygroscopic. Avoid temperatures above 40°C and extreme humidity to prevent caking or degradation. Keep away from incompatible materials and ignition sources. |
| Shelf Life | Shelf life is approximately 2 years from manufacture date when stored unopened in a cool, dry place. |
GOHSENOL EG-40PW is charged into the pre-emulsion make-up tank at 2.5–4.0 wt% based on total vinyl acetate monomer in vinyl acetate-ethylene (VAE) emulsion polymerisation. The grade’s 4% aqueous solution viscosity of 40.0–46.0 mPa·s at 20 °C and degree of hydrolysis of 86.5–89.0 mol% create a narrow colloidal protection window that suppresses coagulum formation in 20 000 L stainless steel reactors equipped with anchor impellers and half-coil jacket cooling. Dissolution of the powder is performed in a stirred make-up vessel at 80–85 °C for 60–90 min, followed by cooling to 55–60 °C before the aqueous phase is transferred under nitrogen pressure. The delayed monomer feed is controlled by Coriolis mass flow meter; the reaction temperature is held at 68–75 °C. A redox couple of ammonium persulfate at 0.25 wt% and sodium metabisulfite at 0.10 wt% on total monomer is used. At EG-40PW addition above 4.5 wt%, the low-shear Brookfield viscosity of a 55% solids dispersion can exceed 8 000 mPa·s, restricting drum discharge and requiring positive-displacement pumps rather than centrifugal discharge. Published reactor data for this grade in high-pressure ethylene copolymerisation is limited; pilot-scale studies of partially hydrolysed PVAL with 2.0–4.0 wt% protective colloid report no particle size inversion and no latex destabilisation. The resulting emulsions are post-treated with t-butyl hydroperoxide and sodium metabisulfite to reduce residual vinyl acetate to below 0.3%. Bulk powder should be stored below 60% RH; if caking occurs due to moisture absorption above 60% RH, the powder is pre-dried at 50–60 °C for 2–4 h before dissolution. Compliance is assessed under FDA 21 CFR 175.105 for adhesives and FDA 21 CFR 176.170 for indirect food-contact paper; REACH registration and ISO 9001 manufacturing documentation are maintained. Terminal products include PVAc homopolymer adhesives, VAE copolymer dispersions for D3/D4 wood laminating, paper-laminating adhesives, and construction mastics.
The surface sizing formulation is prepared by jet-cooking oxidized corn starch at 95–100 °C with EG-40PW at 0.3–1.5 wt% on dry fibre. The grade is pre-dispersed in cold water at 10–15% solids before injection into the starch cooker; the jet pressure is 3.5–4.5 bar and the hold time in the flash tank is 20–30 min. At the size press, the combined size pick-up is maintained at 1.5–4.0 g/m² per side depending on base sheet porosity. The presence of EG-40PW raises film split resistance and reduces dusting on paper machines running above 900 m/min. Cobb values measured by ISO 535:2014 on treated linerboard are typically reduced by 20–30% compared with a starch-only control at the same pick-up, although the magnitude varies with internal sizing level and base paper ash content. The terminal products are uncoated woodfree printing papers, envelope papers, and recycled linerboard. Compliance for food-contact paper and paperboard is evaluated under FDA 21 CFR 176.170 and FDA 21 CFR 176.180; the grade is handled under normal industrial hygiene practice and does not require a hazard statement under the CLP Regulation (EC) No 1272/2008.
Across paper-converting operations where remoistenable adhesive films are applied by roller coater at 60–120 m/min, EG-40PW is dissolved in water to yield a final wet adhesive containing 15–25 wt% polymer and combined with glycerol or sorbitol plasticizer at 5–15 parts per 100 parts of dry polymer. The solution is heated to 85–90 °C until free of gel particles, filtered through 100 µm stainless mesh, and coated onto 60–90 g/m² machine-glazed paper. Drying is arranged in a tunnel with air temperature 90–110 °C to leave a dry adhesive coat weight of 5–8 g/m². The remoistenable gum remains non-tacky below 50% relative humidity but re-wets within 5–8 s when exposed to water at 20 °C. Compliance is referenced to FDA 21 CFR 175.105 for incidental food-contact adhesives; residual formaldehyde in the adhesive film is controlled below 10 mg/kg as determined by quantitative UV-Vis spectroscopy after aqueous extraction. Terminal products include gummed paper tape, envelope flaps, paper tubes, and vegetable seed tape.
EG-40PW is applied in combination with oxidized starch and acrylic ester size at 3–8 wt% of the total size solids. The size is cooked in a continuous jet cooker at 105–110 °C, then held in a storage box at 80–85 °C. In the slasher, single-end or multi-box pre-wet is followed by size box add-on of 6–11% on dry warp. The drying section is set in the first zone at 110–120 °C and later zones at 130–140 °C; warp moisture after drying is controlled at 5–7% for polyester/cotton blends and 7–9% for 100% cotton. The film strength contributed by EG-40PW reduces warp breaks and size shed on air-jet looms; however, size removal must be verified after weaving because over-dried PVA film can form insoluble skin layers. Desizing is performed with amylase for the starch fraction and hot water at 70–80 °C for the PVA fraction; size removal is verified on finished fabric by washing fastness testing under ISO 105-C06:2010. The effluent is monitored for chemical oxygen demand under the European IPPC BREF for textile processing. Terminal products are sized warps for denim, shirting, and technical cotton-polyester fabrics.
In aqueous ceramic tape casting, EG-40PW is introduced at 2–5 wt% of dry ceramic powder and combined with polyethylene glycol plasticizer at 0.5–1.0 wt% of ceramic powder. The slurry is ball-milled with alumina or zirconia media for 24–36 h, de-aired under vacuum at 50–100 mbar for 15–30 min, and cast through a doctor blade with a gap of 200–500 µm onto a polyester carrier. The green tape is dried at 25–35 °C and 60–70% RH to avoid case hardening. Binder burnout is performed in a vented kiln with a hold step at 350–450 °C for 1–2 h to eliminate carbon residues before high-temperature sintering. The heating rate in the debinding step should not exceed 1–2 °C/min between 200 °C and 350 °C to avoid blistering. Thermogravimetric analysis of the binder can be performed according to ISO 11358-2:2021; the grade leaves an ash content below 0.5% as Na2O, a boundary condition for alumina dielectric tape. Terminal products include alumina substrates, zirconia ceramic separators, and low-temperature co-fired ceramic tapes where organic burnout must be complete before metal-paste co-firing.
EG-40PW can be processed into water-soluble film by solution casting or melt extrusion at 170–190 °C with glycerol or trimethylolpropane as plasticizer at 10–30 parts per 100 parts of polymer. For solution casting, the polymer is dissolved at 15–20% solids in water, de-gassed, and coated onto a chromium-plated belt. The wet film is dried in multi-zone ovens at 70–100 °C. Because the grade is partially hydrolysed, surface skin formation occurs if the first drying zone exceeds 100 °C or if ambient relative humidity exceeds 60% during powder storage; pre-drying at 50 °C for 2–3 h is required before dry blending. The dissolution rate in water at 20 °C is faster than fully hydrolysed PVAL grades, which may be relevant for detergent sachet disposal. Compliance is assessed under the EU Detergent Regulation (EC) No 648/2004 and, for packaging materials in contact with detergents, not under food-contact rules. Terminal products include laundry detergent sachets, agrochemical water-soluble pouches, and transfer printing films. Published data for the specific EG-40PW film at 35 µm thickness is limited; film trials require verification of tensile strength by ISO 527-3:2018 and thickness by ISO 4593:2016.
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GOHSENOL EG-40PW is a partially saponified polyvinyl alcohol (PVOH) resin supplied as a powder for waterborne polymerisation and converting operations. The substance is assigned CAS 9002-89-5 and is classified industrially as a vinyl alcohol-vinyl acetate copolymer in which the degree of hydrolysis is controlled to 86.5–89.0 mol%. The commercial specification does not rely on absolute molecular weight; instead, the grade is defined by the viscosity of a 4% aqueous solution at 20 °C, which is 40.0–46.0 mPa·s when measured according to JIS K6726. Additional lot-release values include volatile matter not exceeding 5.0%, ash not exceeding 0.5% as sodium oxide, and pH in the range 5.0–7.0. Under the ISO 15023-1 designation system for poly(vinyl alcohol) thermoplastics, the grade corresponds approximately to a PVAl 40-88 classification; published data for this exact mapping is limited, and procurement specifications should define the certified limits against the manufacturer’s certificate of analysis. The powder form is intended for batch pre-dissolution rather than direct dry addition into high-solids emulsions. Standard packaging is multi-wall paper bags with a moisture barrier liner, typically 20 kg net mass, though regional packaging may differ.
In aqueous preparation, the material is dispersed in demineralised water at 20–30 °C under low-shear agitation, then heated to 85–95 °C for 30–60 min using a jacketed vessel with an anchor or helical ribbon impeller. Partially saponified grades dissolve more readily than fully hydrolysed grades, but high-shear mixing with tip speeds above 3.5 m/s entrains air and can generate stable foam. The target solution concentration for coating lines is usually 10–20% by mass; higher concentrations raise Brookfield viscosity beyond the wetting window of corona-treated polyester films. After dissolution, the solution is filtered through a 150 µm bag filter to remove gel particles and undispersed fragments. The solution pH should be maintained between 4.5 and 8.5. Outside this range, hydrolysis or oxidation reactions shift viscosity and colour during storage. Ambient storage of unpreserved solutions for more than 48 h has been associated with microbial viscosity loss that is not recoverable by re-heating. The grade is incompatible with borate-based thickeners or crosslinkers at alkaline pH because gel networks form before the coating can be transferred. For continuous roll coating, the working viscosity is typically adjusted by dilution to 200–600 mPa·s at the application temperature, measured with a Brookfield RVT spindle 3 at 20 rpm.
During vinyl acetate-ethylene and vinyl acetate-acrylic emulsion polymerisation, the grade functions as a steric stabiliser and viscosity-control agent at the polymer-water interface. In a stirred jacketed reactor with a pitched-blade turbine operating at 2.0–3.0 m/s tip speed, the powder is normally introduced as a pre-dissolved solution at 4–8% solids before monomer addition. The colloid-to-monomer ratio determines the particle nucleation rate and the shear stability of the finished latex; comparable partially hydrolysed PVOH grades with 40 mPa·s nominal viscosity have been used at 3–6% by mass on total monomer in industrial vinyl acetate-ethylene formulations. Published data for this specific product in a single reactor configuration is limited, and the resulting particle size cannot be inferred from colloid viscosity alone. Particle size of the finished dispersion is measured by dynamic light scattering according to ISO 22412:2017 after dilution with deionised water. A higher colloid fraction shifts the volume median diameter toward the lower end of the distribution, but broadens the span when monomer-starved conditions occur in the pre-emulsion feed. Raising the EG-40PW fraction increases latex viscosity and freeze-thaw stability but reduces the water resistance of the dried film unless formulation with ethylene pressure, post-crosslinking, or lower colloid content compensates. Residual monomer content is measured by gas chromatography with an internal standard, not by wet titration. Dry addition into a hot monomer emulsion can produce gel specks that are retained in filtration and reduce coating clarity.
The addition of EG-40PW to polyvinyl acetate-based adhesive formulations modifies low-shear viscosity, wet tack, and set speed. At 50–65% solids, a 2–4% replacement of fully hydrolysed PVOH by EG-40PW lowers the minimum film-forming temperature and increases adhesion to low-energy substrates such as oriented polypropylene. Viscosity response is monotonic with concentration up to approximately 8% solution; above this threshold, the shear-thinning index measured on a cone-and-plate rheometer at 25 °C increases sharply and roller transfer may string. Because the grade is partially hydrolysed, films retain greater molecular mobility and exhibit lower tensile yield stress than fully hydrolysed PVOH films. The residual acetate content reduces ultimate water resistance; formulations intended for water-resistant wood assembly are tested according to EN 204 durability classes. Compounding with plasticisers such as dibutyl phthalate or benzoate esters requires pre-mixed slurries to prevent localised gel particles. The operational pH window is 4.5–8.5; outside this window, viscosity drift and yellowing have been observed in batch mixing.
Partially saponified grades retain a higher concentration of residual acetyl groups than fully hydrolysed PVOH. These acetate groups disrupt interchain hydrogen bonding and lower the crystalline melting peak from above 220 °C in fully hydrolysed grades to approximately 180–190 °C for 86.5–89.0 mol% hydrolysis. In paper surface sizing, EG-40PW can be applied at lower size-press temperatures than fully hydrolysed grades, reducing steam consumption in starch systems. The film formed from a 10% solution has lower tensile strength but greater elongation and folding endurance than fully hydrolysed PVOH, a measurable property difference relevant to lightweight coated paper. Water resistance, quantified by Cobb value according to ISO 535, is inferior to fully hydrolysed PVOH unless an insolubilising agent is used. Barrier coating applications requiring low oxygen transmission should not replace fully hydrolysed grades without re-qualifying oxygen transmission rate according to ASTM D3985. In multi-layer extrusion coating, the grade must be pre-dried to below 0.3% moisture to prevent steam-induced surface defects.
The mid-viscosity position of EG-40PW in the GOHSENOL EG series is shown in Table 1. Exact adjacent-grade viscosity limits depend on the manufacturer’s certificate of analysis; only the EG-40PW range is listed numerically here because published data for the adjacent configurations is limited.
| Property | EG-30PW | EG-40PW | EG-50PW |
|---|---|---|---|
| 4% aqueous solution viscosity at 20 °C | lower | 40.0–46.0 mPa·s | higher |
| Hydrolysis degree | partial | 86.5–89.0 mol% | partial |
| Emulsion viscosity at equal colloid addition | lower | intermediate | higher |
| Film water resistance | similar | baseline | similar |
| Minimum dissolution temperature | similar | 85–95 °C | similar |
The comparison indicates that selecting EG-40PW over a lower-viscosity partial grade increases latex viscosity and shear stability, while selecting a higher-viscosity partial grade increases these properties further but may reduce the maximum practical solids content in spray-dried redispersible powders.
Thermogravimetric analysis of partially saponified PVOH generally shows initial mass loss associated with absorbed water below 150 °C, followed by onset of thermal decomposition near 200 °C. The crystalline melting peak for this hydrolysis range is approximately 180–190 °C, leaving a melt processing window that is narrow; barrel set points on a co-rotating twin-screw extruder with 40:1 to 48:1 L/D must be controlled within ±5 °C. When EG-40PW is melt processed, pre-drying to below 0.3% moisture is required at 60–70 °C for at least 4–6 h in a dehumidified hopper dryer. Higher residual moisture generates steam at the feed throat and causes feeding instability. Extrusion with plasticisers such as glycerol or sorbitol lowers the melting point and broadens the processing window, but the plasticiser must be injected after the polymer has wetted the screw to avoid slip on the barrel wall. The powder is hygroscopic and should be stored in sealed packaging below 60% relative humidity; caking has been observed when bags are left open under humid conditions. Shelf life under these storage conditions is typically 12 months from date of manufacture. The product is not intended for direct food-contact film without formulation-specific compliance testing.
Regulatory documentation for waterborne adhesives and paper coatings commonly references the following standards and regulations for partially hydrolysed PVOH. The presence of GOHSENOL EG-40PW in a formulation does not by itself establish compliance; end-use migration testing and application-specific conditions remain part of the product qualification file.
| Standard/Regulation | Scope | Relevant specification detail |
|---|---|---|
| JIS K6726 | Polyvinyl alcohol test methods | Viscosity, saponification, ash, volatile, pH |
| ISO 15023-1 | PVOH designation basis | Viscosity class 40; hydrolysis class 88 |
| 21 CFR 175.105 | Adhesives for food-contact packaging | Indirect additive, good manufacturing practice |
| 21 CFR 176.170 | Paper and paperboard in contact with aqueous and fatty foods | Extractives limitations apply |
| REACH (EC) No 1907/2006 | EU regulatory framework | Registration and exposure scenario documentation |
Compliance with FDA 21 CFR 177.1670 for polyvinyl alcohol film is relevant only where the grade is converted into a finished film structure; the standard is not automatically applicable to emulsion or coating uses.
