| HS Code | 847676 |
| Product Name | GOHSENOL EG-18P |
| Chemical Family | Polyvinyl alcohol (PVA) |
| Appearance | White to slightly yellowish powder |
| Degree Of Saponification | 86.5 - 89.0 mol% |
| Viscosity 4 Aqueous Solution 20c | 18 mPa·s |
| Ph 4 Aqueous Solution | 6.0 - 7.0 |
| Specific Gravity | 1.25 |
| Bulk Density | 0.4 - 0.6 g/cm3 |
| Ash Content | ≤ 0.5 wt% |
| Volatile Content | ≤ 5.0 wt% |
| Solubility In Water | Soluble, including cold water solubility characteristics |
| Solubility In Organic Solvents | Insoluble in most common organic solvents |
As an accredited GOHSENOL EG-18P factory, we enforce strict quality protocols—every batch undergoes rigorous testing to ensure consistent efficacy and safety standards.
| Packing | GOHSENOL EG-18P is supplied as white granular polyvinyl alcohol in 25 kg multi-layer paper bags for safe handling. |
| Container Loading (20′ FCL) | 20′ FCL loading of GOHSENOL EG-18P: palletized, shrink-wrapped bags, securely stowed to maximize capacity and ensure safe transport. |
| Shipping | GOHSENOL EG-18P is a polyvinyl alcohol (PVA) resin in free-flowing granular form. For shipping, it is classified as non-hazardous, non-dangerous goods. Pack in moisture-proof multi-wall paper or PE-lined bags, or FIBC on pallets. Protect from humidity, direct sunlight, and excessive heat. Keep sealed in dry, well-ventilated conditions. |
| Storage | Store GOHSENOL EG-18P (polyvinyl alcohol) in a cool, dry, well-ventilated area. Keep the container tightly closed to prevent moisture absorption and contamination. Protect from direct sunlight and incompatible oxidizing agents. Avoid generating dust during handling. Use within the manufacturer’s recommended shelf life to maintain quality. |
| Shelf Life | Shelf life is typically 2 years from manufacture if stored in a cool, dry place away from moisture and direct sunlight. |
GOHSENOL EG-18P, a partially hydrolysed poly(vinyl alcohol) grade with a 4 wt% aqueous viscosity of 4.8–5.8 mPa·s at 20 °C under DIN 53015 and a saponification degree of 86.5–89.0 mol%, is metered into the aqueous phase of vinyl acetate–ethylene and vinyl acetate–acrylic emulsion polymerisation as the primary protective colloid. In a 15,000 L glass-lined batch reactor equipped with pitched-blade turbine agitation at 90–120 rpm, the colloid is pre-dissolved in demineralised water at 85–90 °C for 120–180 min, cooled to 40–50 °C, and then combined with the initiator feed system. The addition ratio is typically 3.0–6.0 wt% on total vinyl acetate monomer; below 3.0 wt%, filtration residue on a 250 µm screen tends to increase during latex let-down, while above 6.0 wt%, finished emulsion viscosity can exceed 5,000 mPa·s at 25 °C under ISO 2555. Ethylene pressure in VAE reactors is maintained at 30–80 bar with the polymerisation temperature held at 65–85 °C. Residual vinyl acetate monomer is reduced to <0.1 wt% by a sodium metabisulfite/tert-butyl hydroperoxide redox post-treatment. Borate-based buffers are not recommended in the aqueous charge because poly(vinyl alcohol)–borate complexation can raise viscosity outside the target window. Powder handling from bulk bags at ambient relative humidity above 60 % requires pre-drying or a jacketed hopper at 40–50 °C to avoid screw feeder bridging. Compliance for adhesive end uses is assessed under FDA 21 CFR 175.105; paper and paperboard contact uses are evaluated under FDA 21 CFR 176.170 and 176.180. REACH registration status is verified against Regulation (EC) 1907/2006 and the current supplier safety data sheet. Finished emulsions are subsequently compounded into VAE-based tile adhesives, wood laminating adhesives, paper coating binders, carpet backing compounds, and nonwoven saturation binders.
| Regulatory/standard reference | Application scope | Verification point |
|---|---|---|
| FDA 21 CFR 175.105 | Adhesives and coatings for food packaging laminates | Finished emulsion formulated into adhesive systems; residual vinyl acetate monomer maintained below 0.1 wt% |
| FDA 21 CFR 176.170 | Paper and paperboard components in contact with aqueous and fatty foods | PVOH component extraction testing under intended conditions of use |
| FDA 21 CFR 176.180 | Paper and paperboard components in contact with dry foods | Extraction testing under intended dry-food contact conditions |
| EU Regulation 10/2011 | Plastic materials and articles intended for food contact | Overall migration limit 10 mg/dm²; verify current consolidated annex for PVOH authorisation status |
| REACH (EC) 1907/2006 | Registration, evaluation, authorisation of chemical substances | Confirm registered tonnage band, exposure scenarios, and candidate list status |
In surface sizing of uncoated woodfree and packaging papers, GOHSENOL EG-18P is applied at 0.5–1.5 parts per 100 dry starch solids in combination with oxidised or cationic starch. The starch component is jet-cooked at 125–130 °C for 2–5 min; EG-18P is dissolved separately at 8–10 wt% solids at 85–90 °C and added to the starch solution after cooling to 60–70 °C to avoid retrogradation and viscosity drift in the holding tank. The resulting size-press bath is maintained at 8–12 wt% total solids, with a Brookfield viscosity of 20–80 mPa·s at 60 °C under ISO 2555. Application is performed on a film press or puddle size press at 400–1,200 m/min, with dry pickup controlled to 1.5–3.0 g/m². Paper response is measured according to ISO 535 for Cobb 60-second water absorptiveness, ISO 8791-2 for Parker Print-Surf roughness, and ISO 1924-2 for tensile properties. Food-contact status is supported by FDA 21 CFR 176.170 and 176.180 when the finished paper or paperboard is tested under conditions corresponding to the intended food type. Operational limit: at line speeds above 1,200 m/min, the low solution viscosity can increase film-split misting; a rheology modifier or a higher molecular weight PVOH grade is required. Terminal products include inkjet paper, laser printing paper, release base paper, and folding boxboard.
GOHSENOL EG-18P is used as a component of poly(vinyl alcohol)–starch–acrylic warp sizing formulations for polyester and nylon filament weaving. A production-scale formulation for a 75D/72F polyester warp contains EG-18P at 10–15 wt% of total dry size solids, starch ether at 60–70 wt%, acrylic co-binder at 15–20 wt%, and wax-based lubricant at 0.5–1.0 wt%. The size is prepared in a pressure cooker at 120–130 °C for 45–60 min, then held at 78–82 °C in the size box to prevent surface skin-over. Squeeze rolls are set at 2.5–4.0 bar; dry size pickup is maintained at 6.0–8.0 wt% on dry yarn, determined gravimetrically before and after desizing according to mill-controlled SOP. Drying cylinders are staged from 120 °C to 140 °C surface temperature to avoid rapid crusting. Weaving is performed on air-jet or rapier looms at 600–900 rpm. Compliance for textile auxiliaries is assessed under ZDHC MRSL v3.1 and OEKO-TEX ECO PASSPORT where required. Finished fabric is tested for tensile retention according to ISO 13934-1 and yarn tenacity retention according to ISO 2062. Operational boundary: incomplete desizing at wash temperatures below 80 °C can create dye resist spots on polyester. Terminal products are desized, scoured, dyed woven fabrics for apparel linings, umbrellas, and sportswear shells.
Ceramic green processing with GOHSENOL EG-18P is configured around aqueous tape casting and spray drying of alumina, zirconia, and ferrite powders. The grade is incorporated at 0.5–2.5 wt% based on dry ceramic powder mass, while a polyacrylic acid dispersant is used at 0.2–0.6 wt% and slurry solids are maintained at 55–65 wt%. Dissolution of the binder is carried out in deionised water at 6–10 wt% solids and 85–90 °C for 120 min, followed by cooling to below 30 °C before addition to the mill. Milling proceeds in a ceramic-lined ball mill with zirconia media for 12–24 h; the slurry is de-aired under vacuum at 200–400 mbar absolute pressure. In tape casting, a doctor blade gap of 0.3–1.5 mm is set on a Mylar carrier or stainless steel belt, and drying is performed at 50–70 °C to residual moisture of 0.5–1.5 wt%. For spray-dried press granules, atomisation is performed at inlet air 200–250 °C and outlet 90–120 °C; granule flow is evaluated by Hall flowmeter per ASTM B213. Thermal debinding is conducted at 350–450 °C with heating rate not exceeding 1 °C/min through the decomposition interval to prevent lamination voids and blistering. Green strength of pressed or tape-cast test bars is measured according to ASTM C1161-18. Compliance for electronic ceramic substrates requires absence of restricted heavy metals per RoHS Directive 2011/65/EU Annex II. Terminal finished products include multilayer ceramic capacitor tapes, LTCC substrates, ceramic substrates for power modules, and soft ferrite cores.
Water-activated adhesive gumming for envelopes, stamps, labels, and paper tapes uses GOHSENOL EG-18P as a film-forming binder. A concentrated stock solution is prepared at 10–15 wt% solids in water at 85–90 °C, then cooled to 30–40 °C. Plasticiser glycerol or sorbitol is added at 5–15 wt% based on dry PVOH solids; dextrin is often compounded at 20–40 wt% to adjust open time and tack development. The adhesive is applied to paper via roll coater at 15–25 g/m² wet, then dried in an air-flotation tunnel at 90–110 °C to a moisture content of 2–5 wt%. The dry film is remoistened with water to develop tack; open time is 10–60 s depending on adhesive solids and paper porosity. Compliance for packaging adhesive is evaluated under FDA 21 CFR 175.105; child-safe packaging applications additionally reference EN 71-3 migration limits. Paper tensile strength after adhesive application is measured according to ISO 1924-2; bond failure mode is specified as fibre tear after 24 h conditioning at 23 °C and 50 % relative humidity. Operational boundary: storage of coated sheets above 75 % relative humidity can cause blocking; a slip additive is required for high-humidity distribution. Terminal products include remoistenable envelopes, stamps, labels, paper splicing tapes, and spiral paper tube stock.
Microporous inkjet coatings containing fumed silica or precipitated silica use GOHSENOL EG-18P as binder at 20–40 parts per 100 dry pigment in a coating colour of 15–20 wt% solids. The silica is dispersed under high shear in deionised water with a cationic or nonionic dispersant at 3,000–5,000 rpm for 30–45 min; EG-18P is dissolved separately at 8–10 wt% solids and mixed after cooling to 25–30 °C to prevent pigment shock and micro-gel formation. The coating is applied to resin-coated paper, cast-coated paper, or polyester film by slot die or blade coater at a wet film thickness of 80–150 µm; drying is executed in an air-flotation dryer with zone temperatures from 50 °C to 120 °C to limit binder migration to the surface. Calendering is conducted at 60–80 °C and line pressure 150–250 kN/m. Print quality is evaluated by ISO 13660 for line quality, blurriness, and mottle; coating adhesion is measured by cross-hatch according to ISO 2409. Compliance for printed food-contact matter may reference FDA 21 CFR 176.170 or EU Regulation 10/2011 depending on intended use. Published data for this exact grade and slot-die configuration is limited; pilot coater validation is recommended before production runs. Operational limit: below 20 parts per 100 pigment, silica dusting may appear after calendering; above 40 parts, ink absorption rate may become insufficient for high-speed duplex printing. Terminal products include photo-quality inkjet papers, proofing media, and backlit display film.
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GOHSENOL EG-18P is a partially hydrolysed polyvinyl alcohol powder marketed under the GOHSENOL trade name by Mitsubishi Chemical Corporation. The product is supplied as a free-flowing white to off-white powder with a 4 wt% aqueous solution viscosity at 20 °C typically reported as 20.5–24.5 mPa·s and a hydrolysis degree of 87–89 mol%. The grade also carries a pH of 5–7 in aqueous solution, a volatile matter content not exceeding 5.0 wt%, and an ash content not exceeding 0.5 wt%. Its CAS registry number is 9002-89-5. The residual acetate groups in the partially hydrolysed backbone reduce crystallinity and promote cold-water dispersibility relative to fully hydrolysed polyvinyl alcohol grades, while the intermediate molecular weight provides a balance between solution viscosity and film toughness.
| Property | Typical range | Test basis |
|---|---|---|
| 4 wt% aqueous solution viscosity | 20.5–24.5 mPa·s | JIS K6726, 20 °C |
| Hydrolysis degree | 87–89 mol% | JIS K6726 |
| pH | 5–7 | 4 wt% aqueous solution |
| Volatile matter | ≤ 5.0 wt% | JIS K6726 |
| Ash content | ≤ 0.5 wt% | JIS K6726 |
The residual acetate groups in EG-18P disrupt inter-chain hydrogen bonding more effectively than acetate groups in lower-hydrolysis intermediates. This structural feature reduces the energy required for complete dissolution and lowers the tendency for hot-water gelation during size-press and coating-make-down operations. The product is therefore specified where cold-water-dispersible film formation, controlled viscosity build, and low ash residue are required simultaneously.
On production-scale make-down equipment, EG-18P is most reliably dissolved by first dispersing the powder in ambient water under high-shear agitation. A sawtooth disperser operated at a tip speed of 10–15 m/s disperses the powder without forming partially hydrated agglomerates. The dispersion is then heated to 85–95 °C and held for 30–60 min under low-shear anchor agitation to complete dissolution. Direct steam injection can be used, but local temperature excursions above 95 °C may promote hydrolysis of residual acetate groups and drift in solution viscosity. Jacketed vessels with internal coils provide tighter control in continuous coating plants. The solution should be cooled below 40 °C before adding biocide or pH adjusters. For storage longer than 24 h, a compatible biocide is required because polyvinyl alcohol solutions are susceptible to microbial degradation. Filtration through a 100–200 µm bag filter removes occasional gel specks that can cause coating defects. At relative humidity above 60%, the powder should be pre-dried or stored in sealed silos because moisture uptake can produce bridge formation in screw feeders and off-spec viscosity under gravimetric dosing.
The viscosity of a 4 wt% solution at 20 °C is controlled primarily by molecular weight and concentration. Increasing the solution concentration from 4 wt% to 8 wt% does not produce a linear viscosity increase; the shear-thinning character becomes more pronounced, and low-shear Brookfield viscosity can rise by a factor of several times. For pumping and coating design, rheological curves should be generated on site using ASTM D2196-20 rather than relying on single-point viscosity. The product is compatible with nonionic and anionic wetting agents, but cationic additives may reduce solution clarity or form complexes if the pH exceeds 7.5. Prolonged high-shear mixing after full dissolution can cause mechanical chain scission; rotor-stator mixers should be shut off or bypassed once dispersion is complete. The pH of the finished solution should remain between 5 and 7 for maximum shelf stability. Alkaline pH above 8.5 promotes gradual ester hydrolysis, shifting solubility and viscosity behaviour over time.
Surface sizing operations use EG-18P as a film-forming strength additive in starch-based size press formulations. At size-press solids of 4–8 wt%, addition of 0.5–2.0 parts EG-18P per 100 parts oxidised starch on a dry basis improves surface strength as measured by TAPPI T 459 or ISO 3783. The partially hydrolysed grade disperses at 20–25 °C and does not require dedicated cooking when a pre-dissolved 10 wt% stock solution is used. On high-speed film-transfer coaters running above 1,000 m/min, foaming and misting at the nip can be influenced by coating solids, roll hardness, and machine geometry; mill trials are required to define the operating window. Batches prepared with high calcium-ion mill water may show reduced compatibility with oxidised starch. Water hardness above 300 ppm CaCO3 should be evaluated because viscosity and film clarity can shift.
When EG-18P replaces a lower-viscosity partially hydrolysed grade such as GOHSENOL EG-05 at equal addition, the higher molecular weight of EG-18P generally increases size-press film toughness and surface strength but raises size-press viscosity. Published data for the exact surface strength delta in a given furnish is limited because fibre furnish composition, filler loading, and starch type mask direct comparisons. When EG-18P is compared with fully hydrolysed polyvinyl alcohol grades, the lower hydrolysis range of 87–89 mol% reduces hot-water gelation and permits easier cold-water clean-up but yields a more water-sensitive dried film. In closure operations where water resistance is required after printing, EG-18P should be blended with a fully hydrolysed grade or a crosslinker rather than used as the sole binder.
| Grade category | Hydrolysis profile | 4% solution viscosity at 20 °C | Practical shift relative to EG-18P |
|---|---|---|---|
| GOHSENOL EG-05 | partially hydrolysed | lower | lower solution viscosity and faster substrate penetration; lower film toughness |
| GOHSENOL EG-18P | 87–89 mol% | 20.5–24.5 mPa·s | reference grade for cold-water-soluble film formation |
| Fully hydrolysed GOHSENOL NH-18 | ≥ 98 mol% | similar or higher | higher dissolution temperature, lower cold-water tack, improved water resistance |
| Higher-viscosity partially hydrolysed grades | 87–89 mol% | higher | higher size-press viscosity and higher film tensile; greater pumping load |
In emulsion polymerisation, EG-18P functions as a protective colloid during vinyl acetate and vinyl acetate-ethylene polymerisation. A 10 wt% aqueous stock solution is typically metered into the reactor before initiator addition at 2–6 wt% on total monomer. The residual acetate content of the grade provides a balance between sufficient grafting onto the growing particle surface and colloidal stabilisation of the latex. High-solids latices above 60 wt% may develop excessive viscosity or coagulum at the upper end of this addition range, and the optimum must be determined in the specific reactor. A glass-lined or stainless-steel reactor equipped with a pitched-blade turbine at tip speed of 1.5–2.5 m/s provides adequate monomer dispersion without generating shear-induced coagulum. The final particle size distribution should be measured by laser diffraction; no universal D50 target can be assigned to EG-18P because particle size responds strongly to initiator level, comonomer ratio, and agitation geometry. Compared with lower-molecular-weight partially hydrolysed grades, EG-18P improves dried-film strength but increases latex viscosity at equal solids.
Water-based adhesive formulations use EG-18P to modify open time, wet tack, and set speed. In borate-tackified systems, 1–3 wt% borax on polyvinyl alcohol solids produces a viscosity increase and improves wet tack without immediate gelation at 20–25 °C. Mixing is typically performed in a high-shear disperser at 800–2,000 rpm for 20–30 min until filler agglomerates are dispersed. Temperature during mixing should not exceed 45 °C because borate-crosslinked viscosity declines with rising temperature and premature gelation can occur when the batch is cooled. Adhesion to polar substrates can be evaluated using ASTM D1002 for lap shear and ASTM D903 for peel; actual values are substrate- and formulation-dependent. Plasticisers such as glycerol or polyethylene glycol at 10–20 wt% on polyvinyl alcohol solids reduce film tensile modulus and extend open time. The product should not be combined with amine-functional additives that induce alkaline hydrolysis during storage, nor with strong oxidising agents that degrade the polymer backbone.
For ceramic green-body processing, EG-18P is employed as a temporary binder in aqueous tape-casting and spray-dried granulate formulations because its ash content is limited to ≤ 0.5 wt%. Binder addition of 2–8 wt% on ceramic solids is common, but the optimum depends on particle surface area and green density requirements. In continuous tape casting with a doctor blade gap of 200–800 µm, slurry viscosity is generally held in the 1,500–4,000 mPa·s range at 20 °C. EG-18P contributes shear-thinning behaviour that aids levelling while maintaining adequate green strength. Burnout in air is usually conducted between 250 °C and 500 °C, with residual ash controlled by the product's low ash specification. Fully hydrolysed grades can leave similarly low ash but require higher dissolution temperatures and may produce stiffer tape with higher yield stress. Hard water above 300 ppm CaCO3 should be softened because calcium salts can reduce ceramic dispersant efficiency and may interact with the polyvinyl alcohol binder during drying.
For food-contact packaging and article applications, the regulatory status of EG-18P must be confirmed for the specific end-use and region. The manufacturer can provide current declarations for FDA 21 CFR §175.105, EU Regulation (EC) No 1935/2004, and REACH. Dust control during handling is required even though the polymer is not classified as hazardous under GHS. The ash content at ≤ 0.5 wt% assists in meeting heavy-metal limits where applicable, but trace-metal certification should be requested for electronics-grade or food-contact batches.
EG-18P is stable in unopened packaging for at least 12 months when stored below 30 °C and protected from moisture. Bags should be resealed immediately after use; caking can occur after exposure to relative humidity above 60%. Silos and hoppers handling the powder should be grounded to prevent static discharge, and dust extraction systems should be used to keep respirable dust below occupational exposure limits. These operational constraints are shared with other polyvinyl alcohol powder grades and do not represent a unique limitation of EG-18P.
Films and coatings based on EG-18P retain the moisture sensitivity of partially hydrolysed polyvinyl alcohol. At 50% relative humidity and 23 °C, equilibrium moisture uptake is higher than that of fully hydrolysed grades, and wet tensile properties decline after direct water contact. Tensile properties of cast films should be measured according to ASTM D882 using specimens conditioned at 23 °C and 50% RH for not less than 40 h. When improved water resistance is required, EG-18P is blended with fully hydrolysed grades, or crosslinkers such as glyoxal are added at 5–15 wt% on polyvinyl alcohol solids and cured under heat. The product should not be processed as a thermoplastic without sufficient plasticiser; unplasticised polyvinyl alcohol decomposes near 200 °C before a stable melt is formed, so ISO 1133-1:2022 melt flow testing is not a meaningful specification for this grade. In aqueous coating applications, exposure to alkaline substrates or high-pH formulations above 8.5 can shift solubility and film performance during storage, so compatibility trials are necessary.
