| HS Code | 531884 |
| Product Name | GOHSENOL GH-17 |
| Chemical Family | Polyvinyl Alcohol |
| Manufacturer | Mitsubishi Chemical Corporation |
| Appearance | White granular powder |
| Viscosity 4pct Solution 20c | 23-29 mPa·s |
| Degree Of Hydrolysis | 98.0-98.8 mol% |
| Degree Of Polymerization | 1700 |
| Ph 4pct Solution | 5.5-7.5 |
| Ash Content | ≤0.5% |
| Volatile Content | ≤5.0% |
| Bulk Density | 0.4-0.6 g/cm³ |
| Solubility | Soluble in hot water; insoluble in organic solvents |
As an accredited GOHSENOL GH-17 factory, we enforce strict quality protocols—every batch undergoes rigorous testing to ensure consistent efficacy and safety standards.
| Packing | GOHSENOL GH-17 is supplied in 20 kg multilayer paper bags with a polyethylene liner, palletized and wrapped. |
| Container Loading (20′ FCL) | 20′ FCL container loading of GOHSENOL GH-17: packed in palletized bags, stowed securely, ensuring safe transport and stability. |
| Shipping | GOHSENOL GH-17 is a polyvinyl alcohol resin, generally non-hazardous for transport. Ship in dry, sealed, moisture-proof packaging to prevent caking. Avoid excessive heat, humidity, and direct sunlight. Keep away from incompatible materials, and ensure containers remain intact to prevent spills. No special transport classification is required under standard regulations. |
| Storage | Store GOHSENOL GH-17 in its original, tightly sealed container in a cool, dry, well-ventilated area. Protect from moisture, humidity, and direct sunlight. Keep away from heat sources and incompatible materials such as strong oxidizers. Avoid creating dust; after use, reseal immediately. Under proper conditions, shelf life is typically maintained for several years. |
| Shelf Life | Shelf life is typically 2 years from manufacture when stored in original unopened packaging, in a cool, dry area away from moisture. |
On uncoated woodfree grades run at 900–1,100 m/min, surface sizing with low-viscosity partially hydrolysed PVOH is adjusted at the metering rod rather than at the starch kitchen. GOHSENOL GH-17 is a partially hydrolysed PVOH with a 4% aqueous solution viscosity of 25.0–30.0 mPa·s at 20°C and a hydrolysis degree of 86.5–89.0 mol%. These values allow a 10–12 wt% stock solution to be prepared in a jacketed dissolver at 80–85°C without forming the gel skins common with fully hydrolysed grades. The stock is cooled to 50–55°C and transferred through 150 µm bag filters to the size press circulation tank. Final size press solids are generally held at 6–9 wt% when GH-17 replaces 20–30 dry wt% of oxidized starch. Brookfield viscosity of the working size mix is controlled at 120–180 mPa·s at 50°C. Rod pressure is trimmed between 1.2 bar and 1.8 bar on a 60 mm rod metering system to avoid sheet wrap and rod streaks. Surface property verification uses Cobb absorption per ISO 535 and IGT pick strength per ISO 3783. The terminal paper grades are offset printing, envelope, and inkjet base stock where linting control and wet pick resistance are specified by the converter. Since GH-17 solutions are prone to microbial growth, holding time at 30–40°C should not exceed 24 h unless a biocide active against Pseudomonas fluorescens is added. Borate-based retention aids must be excluded upstream of the size press because borate crosslinks PVOH and raises size-vat viscosity irreversibly.
| Parameter | GH-17 typical range | Reference method |
|---|---|---|
| 4% aqueous solution viscosity at 20°C | 25.0–30.0 mPa·s | JIS K6726 |
| Degree of hydrolysis | 86.5–89.0 mol% | JIS K6726 |
| pH at 20°C | 5.0–7.0 | JIS K6726 |
| Volatile matter | ≤5.0% | JIS K6726 |
| Ash | ≤0.5% | JIS K6726 |
Protective colloid demand in vinyl acetate homopolymer and vinyl acetate-ethylene copolymer polymerisation is dominated by aqueous-phase grafting and steric stabilisation at the particle surface. GH-17 is pre-dissolved at 10–15 wt% in deionised water at 80–85°C and held below 40°C before being charged to the reactor. A typical semi-batch formulation uses 3.0–5.0 parts GH-17 per 100 parts vinyl acetate monomer, with potassium persulfate initiator dosage between 0.2 wt% and 0.4 wt% on monomer. The jacketed stainless-steel reactor is operated at 65–75°C with a helical ribbon agitator at 80–120 rpm. Monomer is metered over 4–6 h to avoid vapour-phase runaway and to maintain a monomer-starved condition during the high-exotherm period. Latex viscosity is measured by ISO 2555 on a Brookfield RVT at 20 rpm and 25°C, and solids content is determined by ISO 3251. Because GH-17 has a low degree of hydrolysis, the resulting latex shows lower thickening and easier cold-water clean-up than fully hydrolysed PVOH. Particle size in PVA-stabilised vinyl acetate systems is process-dependent and typically coarser than surfactant-stabilised controls, so reactor agitation and monomer feed profile must be tuned against each plant. The terminal emulsions are used in wood adhesives, paper saturation, and nonwoven binders. Borax must be excluded from downstream formulations because borate crosslinks PVOH and increases viscosity irreversibly. REACH polymer exemption applies to PVOH, but the vinyl acetate monomer registration status must be confirmed separately by the downstream formulator.
At spiral paper-tube winding speeds above 150 m/min, viscosity drift during the run is a more common cause of bond-area reduction than cohesive film failure. GH-17 is compounded into aqueous paper-converting adhesives at 12–18 wt% solids with 5–10 phr glycerol or sorbitol plasticiser and 0.1–0.3 wt% mineral-oil defoamer. The batch is mixed in a vacuum planetary mixer at 50–60°C to minimise entrained air. Wet adhesive viscosity is maintained between 800 mPa·s and 2,000 mPa·s at 25°C, determined by ISO 2555, so that transfer by ribbed roller or slot die remains uniform at production speed. Open time is controlled by adhesive layer mass at 120–180 g/m² wet on coated and uncoated coreboard. The terminal products include spiral tubes, composite can bodies, and carton side seams. Where tubes may contact dry food, the finished adhesive must be reviewed against 21 CFR 175.105, and the complete formulation dossier is required before use. Foaming is the main failure mode on high-speed converting lines; air entrainment above 2 vol% causes skipped bond lines and fibre-tear variation. GH-17 formulations therefore require both vacuum deaeration and a defoamer that remains effective at the application shear rate.
In slasher sizing of 65/35 polyester/cotton warp yarns, GH-17 is combined with thin-boiling starch and a fatty ester lubricant to depress fibre hairiness at the splitting rods. Size mix solids are held at 9–11 wt%, with GH-17 comprising 20–35 dry wt% of the total film former. The PVOH is pre-dissolved separately at 8–10% solids and added to the starch cook at 85–90°C. Size box temperature is held at 85–90°C and viscosity is maintained at 60–120 mPa·s on a Brookfield LV spindle at 30 rpm. Squeeze pressure on the final mangle is set at 0.4–0.6 MPa to control size add-on. The partial hydrolysis of GH-17 permits desizing at 70–80°C with neutral detergent, and the target residual size on scoured fabric is below 0.5% by weight. Warp tensile strength after sizing is compared with unsized yarn by ASTM D2256, and hairiness is assessed by Zweigle or Uster hairiness meters. Terminal products are shirting, workwear, and lining fabrics where subsequent dyeing requires low residual PVOH on the filament surface. Size house operators should avoid prolonged holding at 95°C under high shear because partially hydrolysed PVOH undergoes oxidation and chain scission, which reduces film toughness and lowers warp abrasion resistance on the loom.
GH-17 is used as a low-ash temporary binder for dry-pressed alumina, zirconia-toughened alumina, and mullite bodies. The solution is prepared at 6–10 wt% solids in deionised water and added to the ceramic slurry before spray drying. Addition levels of 0.5–2.0 wt% binder on dry ceramic mass are common for submicron alumina powders. Spray-dryer conditions of 180–220°C inlet and 90–110°C outlet produce free-flowing granules with 1.0–2.5 wt% residual moisture. The binder contributes green strength after uniaxial pressing at 100–150 MPa. Green strength is measured in three-point bending per ISO 14704, but published data for GH-17-specific green strength values in all oxide systems is limited, so press trials are required on each powder lot. Binder burnout is conducted in air at 350–500°C with an oxygen flow sufficient to keep residual carbon within the ceramic manufacturer's loss-on-ignition limit before sintering. The low ash content of GH-17 reduces glassy phase contamination in high-purity alumina bodies. Reducing atmospheres during burnout must be avoided because carbon reduction of alumina surfaces can become significant above 600°C if oxygen is restricted.
GH-17 is applied as a strippable water-based masking layer prior to CNC cutting, press-brake forming, or glass edge grinding. The solution is prepared at 8–12 wt% solids in warm water and then cast by airless spray, curtain coater, or reverse roll. Wet film is dried at 80–100°C to a dry film thickness of 20–40 µm. The low hydrolysis degree of GH-17 supports peel removal after processing without alkaline or solvent-based cleaning. Adhesion to the substrate must be high enough to prevent ingress of cutting fluid but low enough for manual peel. Peel adhesion is measured by ISO 29862, with values varying according to substrate surface energy and applied coat weight. The film re-wets under relative humidity above 70%, so storage of masked sheet must be controlled to avoid premature release or blocking in the stack. Terminal applications are flat glass, aluminium composite panel, and tinplate packaging blanks where edge grinding or cutting generates abrasive slurry that must not contact the polished surface.
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GOHSENOL GH-17 is a partially saponified polyvinyl alcohol resin, CAS 9002-89-5, supplied by Mitsubishi Chemical Corporation under the GOHSENOL polyvinyl alcohol series. The grade is controlled principally by two indices: saponification degree and the viscosity of a 4% aqueous solution at 20 °C. Published release data list a saponification degree of 86.5–89.0 mol%, a solution viscosity of 27.0–33.0 mPa·s determined by JIS K6726, a pH of 5.0–7.0, a volatile matter content not exceeding 5.0 wt%, and an ash content not exceeding 0.5 wt%. The residual acetate groups in the polymer chain lower crystallinity relative to fully hydrolysed polyvinyl alcohol; the practical consequences are cold-water solubility, lower film tensile modulus, and higher moisture sensitivity. Within the GOHSENOL GH series, GH-17 occupies the mid-viscosity segment: it is more viscous than low-viscosity grades used for rapid wet-out and less viscous than high-viscosity grades such as GH-23, which can raise pump back-pressure and coating-colour viscosity beyond workable limits. The grade is therefore evaluated where the polymer must function simultaneously as a protective colloid, binder, and film former.
Differentiation from fully saponified grades is substantial. GH-17 has residual acetate groups that interrupt intramolecular hydrogen bonding; this lowers the crystalline melting point and permits dissolution at lower temperatures, but it also reduces film tensile modulus and water resistance. When maximum water resistance is required, a fully saponified grade is selected instead. Within the same partially saponified class, viscosity is the main selection discriminator: low-viscosity grades require shorter dissolution times and produce lower solution viscosity, while high-viscosity grades increase film strength and thickener efficiency but are harder to transfer and de-foam. GH-17 is selected when the formulation requires a moderate viscosity contribution without excessive shear sensitivity.
Vinyl acetate and vinyl acetate–ethylene polymerisations use partially saponified PVOH as the primary aqueous-phase stabiliser. In a jacketed stainless-steel reactor at 60–80 °C with a pitched-blade turbine, GH-17 is typically screened at 2–6 wt% based on monomer mass. At 86.5–89.0 mol% saponification, the polymer retains sufficient acetate groups to act at the monomer–water interface while retaining enough hydroxyl groups to form a steric barrier around growing particles. The 27.0–33.0 mPa·s viscosity of a 4% solution indicates a molecular weight class that produces reproducible particle-size control without the baffle build-up and reactor-scale fouling observed with higher-viscosity protective colloids. On production lines, high-viscosity grades can cause cavitation at the positive-displacement pump after the hold tank; the lower solution viscosity of GH-17 at equal solids reduces transfer-line back-pressure and shortens grade-change purge time. Published quantitative particle-size distributions for this specific grade in commercial reactor geometries are limited; pilot trials are necessary for scale-up.
At the start of the polymerisation, the aqueous phase contains PVOH and initiator; the degree of hydrolysis controls the grafting reaction between PVOH and vinyl acetate. Residual acetate groups increase surface activity, while hydroxyl density governs hydrogen bonding with the developing polyvinyl acetate surface. If the viscosity is too high, the reactor can develop wall scale on baffles and the heat-transfer coefficient can fall; if too low, particle flocculation may occur at high solids. GH-17 is therefore matched to medium-solids emulsions that are held below 55% solids content before final let-down. The typical concentration range of 2–6 wt% on monomer is not a universal optimum; it depends on monomer composition, initiator half-life, and the surface area of the reactor cooling jacket.
Adhesive compounding uses GH-17 where cold-water dispersibility and moderate thickening are required. The powder can be pre-dispersed in water at 25–30 °C and then heated to 80–90 °C to produce stock solutions without the alkaline cooking step used for starches. In paper and board coating, the grade is screened at 0.5–2.0 parts per hundred parts of pigment on a dry-binder basis; surface strength is commonly assessed by IGT pick resistance under ISO 3783. Coating-colour rheology remains the limiting factor: at equal solids, substituting a higher-viscosity PVOH with GH-17 lowers the low-shear viscosity and may require a solids increase of 1–3 percentage points to maintain blade-coater film weight. Blade coater formulations based on GH-17 can show shear-thinning behaviour. Depending on solids, low-shear viscosity may exceed 1,000 mPa·s; under blade shear, the apparent viscosity drops. If low-shear viscosity is too high, streaking and blade chatter appear. Replacing GH-17 with a lower-viscosity grade may reduce chatter but weakens surface strength. This trade-off is a central process conflict in paper coating and must be resolved by pilot coater runs rather than by extrapolation from solution viscosity alone.
The following release-control properties are referenced in the product certificate of analysis. They are measured in accordance with JIS K6726, which specifies the preparation and conditioning of aqueous PVOH solutions for viscosity, saponification, pH, volatile matter, and ash determinations. Values vary slightly by production lot and region; the certificate of analysis controls for the specific shipment.
| Control property | Method basis | Release range |
|---|---|---|
| Saponification degree | JIS K6726 | 86.5–89.0 mol% |
| Solution viscosity, 4% aqueous at 20 °C | JIS K6726 | 27.0–33.0 mPa·s |
| pH at 20 °C | JIS K6726 | 5.0–7.0 |
| Volatile matter | JIS K6726 | ≤5.0 wt% |
| Ash content | JIS K6726 | ≤0.5 wt% |
These values establish the chemical identity and lot consistency of GH-17 but do not, by themselves, guarantee performance in a formulated adhesive or coating. End-use qualification must include film tensile testing, where relevant, under ISO 527-2 using type 5 specimens, and moisture-resistance testing appropriate to the construction or packaging specification.
Dissolution of GH-17 is concentration-dependent and must be managed to avoid fish-eye defects. For stock solutions up to 10% solids, the powder should be dispersed in cold water under high-turbulence agitation before heating to 80–90 °C. A jacketed vessel with an anchor agitator or double-helix blade provides sufficient heat transfer and avoids localised high concentration at the vessel wall. Above 12% solids, solution viscosity rises sharply, and the limiting parameter becomes available heat-transfer area. The powder is hygroscopic; storage at relative humidity above 60% increases caking tendency, and material intended for melt processing should be pre-dried at 60–80 °C to ≤0.5 wt% moisture. Borate-based additives must not be introduced into PVOH stock solutions because borate ions complex with the hydroxyl groups of PVOH and can form gel bodies that block metering pumps and filters. This incompatibility is particularly relevant in starch adhesive formulations that use borate-modified starches.
Although GH-17 is primarily used as an aqueous solution, melt processing is possible when plasticisers are added. The thermal window is narrow; partially saponified PVOH with 86.5–89.0 mol% saponification typically shows melting near 180 °C and thermal degradation onset near 200 °C. Barrel set points should be held within ±5 °C of the established process temperature when using a co-rotating twin-screw extruder with an L/D ratio of at least 32:1. The powder should be introduced by gravimetric feeding, after pre-drying, into the first barrel section, with plasticiser injection after the melt seal. Processors should monitor melt temperature and die pressure continuously because yellowing and crosslinking are the primary failure modes at the upper end of the temperature range. Published data for GH-17 in specific extruder configurations is limited; temperature-sweep trials are required because degradation onset shifts with plasticiser type, screw speed, and residence time distribution.
Textile warp sizing is a high-shear film-forming application in which GH-17 is applied from a size box at 70–80 °C and dried on hot cylinders. Compared with fully hydrolysed PVOH, the partially saponified grade gives lower film tensile strength and higher elongation, reducing end breakage in shuttleless weaving but increasing moisture uptake in high-humidity weaving sheds. On a slasher sizing machine, add-on is controlled by nip pressure and size-box solids; GH-17 at 70–80 °C yields a uniform film because its molecular weight class permits stable size-box viscosity. For food-contact applications, the grade must be validated against the relevant regulatory reference, such as 21 CFR 175.300 or 21 CFR 177.1670; no blanket food-contact approval is conveyed by the resin designation alone. REACH and RoHS obligations are determined by the formulated article and the importing jurisdiction, not by the resin grade in isolation.
