| HS Code | 168604 |
| Product Name | GOHSENOL GH-20 |
| Chemical Identity | Polyvinyl alcohol (PVA) |
| Cas Number | 9002-89-5 |
| Appearance | White to slightly yellowish granular powder |
| Degree Of Hydrolysis | 86.5-89.5 mol% (partially hydrolyzed) |
| Viscosity 4 Aqueous Solution 20 C | 20-30 mPa·s |
| Ph 4 Aqueous Solution | 5.0-7.0 |
| Volatile Matter | ≤ 5.0% |
| Ash Content | ≤ 0.5% |
| Specific Gravity | 1.27-1.31 |
| Solubility | Soluble in hot water; practically insoluble in organic solvents |
| Melting Point | Approximately 200-230°C (with decomposition) |
As an accredited GOHSENOL GH-20 factory, we enforce strict quality protocols—every batch undergoes rigorous testing to ensure consistent efficacy and safety standards.
| Packing | GOHSENOL GH-20 is supplied in 25 kg multi-wall paper bags with a polyethylene liner, ensuring safe handling and storage. |
| Container Loading (20′ FCL) | GOHSENOL GH-20 is loaded in a 20′ FCL, with palletized bags secured tightly, protected against moisture and damage during transit. |
| Shipping | GOHSENOL GH-20 is polyvinyl alcohol resin, typically supplied as white powder or granules. It is not classified as dangerous goods for transport under IMO/IMDG, ADR, or IATA. Ship in sealed, moisture-proof bags or drums, protected from humidity and dust, and keep away from ignition sources. |
| Storage | Store GOHSENOL GH-20 in its original, tightly closed container in a cool, dry, well-ventilated area. Protect from moisture, humidity, and direct sunlight, as the material is hygroscopic. Keep away from oxidizing agents and incompatible chemicals. Avoid temperatures above 40°C. Ensure proper labeling and segregation to prevent contamination or accidental spillage. |
| Shelf Life | GOHSENOL GH-20 has a shelf life of approximately two years when stored in a cool, dry place in its original sealed container. |
During batch copolymerisation of vinyl acetate at 50–55% total solids, GOHSENOL GH-20 is delivered to the reactor as a pre-dissolved 10% aqueous solution that contributes 30–50% of the total water charge. The grade carries a hydrolysis degree of 86.5–89.0 mol%, a 4% aqueous solution viscosity of 20.0–26.0 mPa·s at 20 °C, a pH of 5.0–7.5, ash not exceeding 0.3%, and volatile content not exceeding 5.0%; these parameters are determined under ISO 2555:2018, ISO 976:2013, and ISO 3251:2019. The protective colloid loading is set within 1.0–6.0 wt% relative to total monomer, with 3.5–5.0 wt% common for vinyl acetate homopolymers and vinyl acetate–ethylene copolymers because this range stabilises particle size without excessive low-shear viscosity drift. The polymerisation is carried out in a jacketed glass-lined reactor equipped with a pitched-blade turbine and baffles, at 70–85 °C, using ammonium persulfate and sodium metabisulfite as a redox initiation system; monomer is delayed over 3–5 h while the turbine maintains a tip speed of 1.2–2.0 m/s to limit coalescence. Graft copolymerisation of partially hydrolysed polyvinyl alcohol with vinyl acetate produces the in-situ amphiphilic graft polymer that controls latex particle size and shear stability; particle size distribution shifts upward if GH-20 is added below 2.0 wt% or if the anionic surfactant concentration exceeds the point of competitive adsorption. Post-polymerisation residual monomer is reduced with tert-butyl hydroperoxide and ascorbic acid at 55–65 °C. The resulting dispersions are tested for viscosity by ISO 2555:2018, non-volatile matter by ISO 3251:2019, and adhesive classification under EN 204:2016; grades intended for indirect food-contact lamination are evaluated against FDA 21 CFR 175.105 and REACH (EC) No 1907/2006. Terminal product types include polyvinyl acetate woodworking adhesives, paper-to-paper laminating adhesives, nonwoven binders, and architectural matt and semi-gloss paints. Powder stored at relative humidity above 60% must be pre-dried before dissolution to avoid lumping and dosing error, and borate salts must be excluded unless deliberate viscosity build or gelation is required.
Fine paper and linerboard mills running 400–1200 m/min introduce GOHSENOL GH-20 into the size press circuit as a 10–15 wt% cooked solution blended with oxidised corn starch or styrene acrylic surface size to raise surface strength without excessive film splitting at the nip. The size bath formulation normally contains 0.5–2.0 wt% dry GH-20 on total liquid mass, corresponding to 5–20 kg dry GH-20 per 1000 L of prepared size; the dry pick-up on the sheet is controlled by rod pressure, blade angle, or puddle level and is commonly 1.5–4.0 g/m² per side. The preparation sequence uses a batch cooker heated to 95 °C for 25–30 min, followed by transfer to a holding tank at 60–70 °C, from which the size is delivered to a rod-metered or film-press station. The downstream process requires continuous viscosity checks at 60 °C because GH-20 retrogrades with starch on cooling and can form gel bodies if the storage hold time exceeds 4 h. Sheet testing follows ISO 535:2023 for Cobb water absorptiveness, ISO 3783:2006 for IGT pick resistance, ISO 287:2017 for moisture content, and TAPPI T 441 for water absorptiveness of sized board; food-contact paper and board are assessed for extractives under FDA 21 CFR 176.170. Terminal finished products include offset printing papers, inkjet base papers, coated folding boxboard, and food-contact linerboard. Foaming in the size press loop increases with surfactant carryover from recycled furnish; a food-contact-approved defoamer is required, and GH-20 dosage above 2.5 wt% is generally avoided because the high-shear viscosity rise narrows the operating window of the metering applicator.
On single-box slasher ranges processing 65/35 polyester–cotton warp yarns of Ne 20–40, GOHSENOL GH-20 is blended into the size mix at 6–12 wt% solids, with a dry add-on target of 3–7 wt% on warp yarn mass; the exact loading is adjusted according to loom type, weft density, and fibre hairiness. The size is prepared in a jet cooker at 100–120 °C, held at 85–90 °C in the size box, and applied through a squeeze roll assembly with nip pressure set to 8–20 kN/m; the sized warp then passes over drying cylinders at 100–130 °C at 40–80 m/min. This partially hydrolysed PVA grade deposits a tough but flexible film that reduces yarn hairiness and improves weaving efficiency; however, single-end tensile retention is limited by film brittleness if the dry add-on exceeds 8 wt% or if the drying cylinder temperature exceeds 135 °C and thermal embrittlement occurs. Sized yarn is conditioned and tested under ISO 139:2005 with tensile measurement by ISO 2062:2009; chemical conformance to restricted substance lists is assessed against ZDHC MRSL v3.1 and OEKO-TEX Standard 100. After weaving, desizing is conducted with hot water at 80–95 °C plus oxidising agents or enzymatic formulations, and the effluent COD load requires ultrafiltration or membrane recovery because GH-20 is poorly biodegradable in conventional activated sludge. Terminal finished products include woven apparel fabrics, workwear sheeting, home textiles, and lining fabrics. Sized beam storage above 65% relative humidity must be avoided because the PVA film plasticises, blocking adjacent yarn ends and causing loom stop marks.
Film casting from aqueous GOHSENOL GH-20 solution is carried out on slot-die coating lines in which the dissolved polymer is deaerated under vacuum and brought to 80–90 °C before entering a heated die. The casting solution is prepared at 10–18 wt% solids, with glycerol or triethylene glycol plasticiser at 5–15 phr, a non-ionic surfactant at 0.1–0.5 wt%, and an internal release agent at 0.05–0.2 wt%; the solution viscosity is verified by ISO 2555:2018 at 80 °C, with the upper bound set by the slot-die manufacturer for uniform flow. The solution is cast onto a chill roll or steel belt maintained at 70–95 °C, dried in a multi-zone tunnel at 80–120 °C, and conditioned to 8–12% moisture before in-line slitting. The downstream process depends on controlled water content: below 6% moisture the film becomes too brittle for slitting, while above 15% moisture the film blocks on the roll. Film tensile properties are measured by ISO 527-3:2018, and non-volatile residue by ISO 3251:2019; packaging films for detergent unit doses are subject to soluble-film dissolution performance tests specified by customer release specifications, with published standardised data for this specific GH-20 configuration being limited. Terminal finished products include water-soluble laundry detergent pouches, agrochemical water-soluble sachets, embroidery backing film, and transfer printing release film. The operational boundary for this grade is set by humidity dependence: storage above 65% relative humidity plasticises the film and reduces tensile modulus, and borate-containing additives must be avoided unless delayed solubility is required.
In aqueous ceramic slurry systems the interplay between binder content, plasticiser level, and drying rate determines green tape flexibility and lamination quality. GOHSENOL GH-20 is added at 2.0–6.0 wt% based on dry ceramic powder mass, with glycerol or polyethylene glycol plasticiser at 20–40 wt% of the binder solids, and the slurry is milled at 60–75 wt% total solids. The slurry is deaerated under vacuum, cast onto polyethylene terephthalate carrier film through a doctor blade gap of 100–500 µm, and dried at 50–80 °C; drying air velocity and temperature ramp are controlled to prevent surface skin formation and binder migration. Green tape is rewound, punched or stamped, laminated under heat and pressure, and then subjected to binder burnout in air or nitrogen at 500–600 °C with a ramp of 0.5–1.0 °C/min to prevent cracking and carbon residue. Thermogravimetric analysis according to ISO 11358-1:2014 is used to verify decomposition onset and residual ash, and flexural strength of densified ceramic samples is measured by ASTM C1161-18 or ISO 14604:2012 as applicable to the final component. The terminal product types include multilayer ceramic capacitor dielectric tapes, low-temperature co-fired ceramic substrates, piezoelectric actuator tapes, and solid oxide fuel cell electrolyte tapes. Published data for GH-20 in specific ceramic matrices is limited; the residual ash specification must be determined for each ceramic powder because sodium and ash content from the polyvinyl alcohol can affect sintered grain boundaries. Green tape storage below 50% relative humidity is required, and the aqueous slurry must be cast within 24–48 h to avoid viscosity drift from polymer hydrolysis or microbial contamination.
Paper sack and board lamination adhesive compounding with GOHSENOL GH-20 proceeds through a controlled dissolution sequence before dextrin or starch derivatives are introduced. The finished adhesive incorporates GOHSENOL GH-20 at 4–10 wt% of the wet formulation, replacing 20–30 wt% of the starch ether component; full replacement is generally limited by the resulting Newtonian flow and reduced trowel hold-out. The mixing process uses a jacketed 316L stainless steel dissolver with a Cowles high-shear blade: water is charged at 25 °C, GH-20 is added slowly under agitation, the batch is heated to 90–95 °C and held for 30 min, then cooled to 60 °C before defoamer, plasticiser, preservative, and starch/dextrin are added. Viscosity is measured by ISO 2555:2018 at 23 °C; lap-shear strength development is assessed on beech or aluminium substrates by ISO 4587:2003, and non-structural wood adhesive classification is verified under EN 204:2016 for D2 service conditions. Terminal finished products include paper sack bottom paste, spiral tube winding adhesives, board lamination adhesives, and case and carton sealing compounds. The operational limitation of GH-20 in these systems is moisture sensitivity: without crosslinker the dry film redisperses under wet conditions, so grades specified for D3 or exterior exposure require additional crosslinking or co-binder modification. Borax, when added to increase tack and cohesion, produces a sharp viscosity maximum and must be dosed at 0.1–0.5 wt% to avoid gelation; prolonged high-shear mixing above 80 °C should be avoided to prevent viscosity drift and microgel formation.
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GOHSENOL GH-20 is a partially hydrolyzed polyvinyl alcohol resin supplied as a white to pale-yellow granule or powder. The grade belongs to the GOHSENOL GH series, in which the numeral denotes a target viscosity plateau rather than a filler content or copolymer ratio. The resin is characterized by a degree of hydrolysis of 86.5–89.0 mol%. A 4% aqueous solution prepared under JIS K6726 conditions exhibits a viscosity of 20.0–26.0 mPa·s at 20 °C. The solution pH is controlled within 5.0–7.0, volatile content is limited to ≤5.0%, and ash content is limited to ≤0.5%. The retained acetate groups reduce crystallinity and alter dissolution temperature, moisture sensitivity, and adhesion to hydrophobic substrates relative to fully hydrolyzed grades.
Routine release testing follows JIS K6726 methods for polyvinyl alcohol. The specified intervals are not nominal descriptors; they impose formulation constraints. A production lot at the upper boundary of 26.0 mPa·s yields measurably higher wet adhesive viscosity than a lot at 20.0 mPa·s at identical solids. During tank-side viscosity adjustment on a steam-jacketed dissolver with a single-shaft agitator, operators typically reduce solids in incremental steps of 0.5 wt% until the target application viscosity is reached. The adjustment is empirical and must be repeated for each incoming batch when narrow slot-die coatability or roller-transfer uniformity is required.
| Property | Specification | Test method |
|---|---|---|
| Degree of hydrolysis | 86.5–89.0 mol% | JIS K6726 |
| Viscosity, 4% aqueous solution | 20.0–26.0 mPa·s at 20 °C | JIS K6726 |
| pH, 4% aqueous solution | 5.0–7.0 | JIS K6726 |
| Volatile content | ≤5.0% | JIS K6726 |
| Ash content | ≤0.5% | JIS K6726 |
| Appearance | White to pale-yellow powder or granules | Visual |
During high-shear dispersion in a baffled polymerization reactor, GH-20 functions as a protective colloid for vinyl acetate, vinyl acetate-ethylene, and acrylic co-monomer systems. Batch and semi-continuous emulsion polymerizations commonly use protective-colloid loadings of 2–6 wt% based on total monomer. The lower end favors smaller particle-size distributions, while the upper end increases latex viscosity and shear stability. The acetate groups present at 86.5–89.0 mol% hydrolysis provide hydrophobic anchoring at the monomer droplet surface; the pendant hydroxyl groups extend into the aqueous phase and build steric barriers against coalescence. As polymerization progresses, vinyl acetate grafts onto the polyvinyl alcohol backbone, producing PVOH-g-PVAc species that enhance steric stabilization but also raise high-shear viscosity. In production-scale vinyl acetate-ethylene emulsion reactors, staged addition of the GH-20 solution at 20–25 °C through a dosing line avoids heterogeneous grafting caused by local protective-colloid depletion. If the aqueous charge is preheated above 80 °C for feed sterilization, slight viscosity drift may occur over the batch. Published data for that specific configuration is limited, and pilot trials are required before a fixed thermal profile is transferred to production.
Dissolution of GH-20 at 10–20 wt% solids for adhesive or coating compounding begins with dispersion of the granules in cold water under agitation. Direct addition to hot water produces surface gelation and lump formation. Once the dispersion is uniform, the batch is heated to 70–85 °C for partial-hydrolysis grades; fully hydrolyzed grades require 85–95 °C. The solution is then cooled to 40–50 °C before plasticizer addition because glycerol and sorbitol can temporarily increase viscosity by competing for bound water. Borax or boric acid addition increases solution viscosity through diol complexation. For a 10 wt% GH-20 solution, borax additions as low as 0.05–0.2 wt% of solution mass can produce a marked viscosity increase or gelation. Borax-compatible formulations therefore require incremental titration while monitoring Brookfield viscosity at 20 °C. Stored aqueous solutions should be protected with an approved biocide; without preservative, aerobic bacteria can reduce solution viscosity within 48–72 h at 20–30 °C.
Paper surface-sizing formulations with GH-20 are applied on puddle or metered size presses at solids of 2–6% and solution temperatures of 40–60 °C. The partially hydrolyzed grade produces lower foaming under high shear than fully hydrolyzed grades and contributes film flexibility at low plasticizer addition. In pigment coating, GH-20 can be used at 2–4 parts per 100 parts pigment by dry weight as a co-binder with styrene-butadiene latex. The polyvinyl alcohol contributes water retention, pick strength, and oxygen barrier after calendering. Wet-coating runs on a blade coater must account for the shear-thinning behaviour of the PVOH solution; apparent viscosity at 10,000 s⁻¹ is lower than low-shear Brookfield values because the polymer chains orient under shear. Oil resistance of the coated surface depends on hydrolysis. Because GH-20 is partially hydrolyzed, oil resistance is lower than that of fully hydrolyzed grades unless a crosslinker is added or the coating is calendered at sufficiently high temperature.
At equivalent concentration, GH-20 differs from fully hydrolyzed polyvinyl alcohol grades having hydrolysis above 98 mol% in three critical properties: dissolution temperature, film water sensitivity, and hydrophobic-surface adhesion. The residual acetate content disrupts crystallite packing and lowers the heat of fusion. As a result, GH-20 enters solution at 70–85 °C rather than the 85–95 °C range required for fully hydrolyzed grades. Films cast from GH-20 display lower tensile modulus, greater elongation, and higher moisture sensitivity than fully hydrolyzed films unless a crosslinker is incorporated. The 20.0–26.0 mPa·s viscosity class places GH-20 above lower-viscosity partially hydrolyzed grades in wet pick resistance and below higher-viscosity grades in flow-out. It is therefore selected when both coat-weight control and film cohesion are required in paper, adhesive, or ceramic binder formulations.
| Property | GOHSENOL GH-20 | Fully hydrolyzed PVOH |
|---|---|---|
| Degree of hydrolysis | 86.5–89.0 mol% | ≥98 mol% |
| Dissolution temperature | 70–85 °C | 85–95 °C |
| Film water resistance | Moderate without crosslinker | High |
| Adhesion to hydrophobic substrates | Higher due to residual acetate groups | Lower |
| Foam tendency under high shear | Lower than fully hydrolyzed | Higher |
Food-contact applications may reference 21 CFR 175.105 for adhesives and 21 CFR 176.170 for paper and paperboard components. Polyvinyl alcohol film applications may additionally reference 21 CFR 177.1670. End-use validation is required because migration and extraction depend on coating weight, substrate, contact food type, and thermal history. Store GH-20 in closed containers at 10–35 °C and below 60% relative humidity to prevent caking. Avoid strong acids, strong bases, and oxidizing agents. Solutions held below pH 4 or above pH 9 at elevated temperature can accelerate hydrolysis or backbone degradation. Dry powder handling requires dust control because polyvinyl alcohol dust can form combustible mixtures under specific airborne concentrations.
