GOHSENOL KH-17

In vinyl acetate-ethylene (VAE) emulsion polymerization, KH-17 acts as the aqueous protective colloid that governs particle size distribution, coagulum formation, and final dispersion viscosity. The grade is charged as a 10.0–15.0% w/w stock solution prepared at 80–90°C with a hold time of 4–6 h under slow pitched-blade agitation. Undissolved granules are removed through a 100 µm stainless steel filter before the reactor charge. Typical KH-17 addition levels for high-viscosity wood-adhesive emulsions fall between 2.0 and 6.0 parts per hundred parts monomer. The lower end produces low-viscosity products. The upper end produces shear-thinning, pseudoplastic dispersions with viscosity above 8,000 mPa·s at 25°C measured by a Brookfield RVT spindle 5 at 20 rpm. The reactor is usually a jacketed stainless steel vessel with a turbine agitator operated at tip speeds of 1.5–3.0 m/s. Vinyl acetate and ethylene are metered under pressure. Ethylene partial pressure is adjusted to 20–45 bar depending on target glass transition temperature. Redox initiation via potassium persulfate/sodium metabisulfite is typical. Polymerization temperature is controlled between 60°C and 80°C. The final dispersion is formulated into D3 wood adhesives under EN 204 and nonwoven binders. Compliance for indirect food-contact use falls under FDA 21 CFR 175.105 for adhesives and 21 CFR 176.170 for paper and paperboard components. KH-17 solutions must not be combined with borax, boric acid, or borate salts because polyvinyl alcohol-borate complexes induce immediate viscosity rise or gelation. Aqueous stock solutions stored beyond 48 h without biocide at 20–25°C may develop microbial growth and pH drift. Cooling to ≤10°C or addition of 0.1–0.3% sodium benzoate is required if storage is unavoidable.

What Limits Slasher Cylinder Speed in Cotton/Polyester Warp Sizing?

Slasher cylinder speed in cotton/polyester warp sizing is often limited by KH-17 film deposition uniformity rather than by yarn tensile failure. The size-box formulation for a 65/35 polyester/cotton blend typically contains KH-17 at 2.0–4.0 kg per 100 L deionized water alongside starch at 30–50 kg and an acrylic co-binder at 2.0–5.0 kg. Size-box solids are held at 8.0–12.0% and temperature at 85–95°C. Partially hydrolyzed polyvinyl alcohol solutions below 80°C develop insufficient flow to penetrate the yarn bundle. Immersion roll and squeeze roll pressures are set to 15–25 kN/m linear load to obtain a size pick-up of 10–15% dry size on yarn mass. Drying cylinder surface temperature is staged at 120°C, 130°C, and 140°C. Yarn moisture after drying must remain below 2.0% before leasing. The final woven fabric is desized and tested under ISO 2062:2010 for yarn tensile strength retention. In weaving, warp stops per 10,000 pick insertions increase when the PVA film becomes brittle after overdrying above 145°C. Therefore, the upper drying temperature boundary is critical. KH-17 should not be blended with hard water above 300 ppm CaCO₃ because insoluble calcium salts reduce film clarity and size-box viscosity stability.

Blade-coater runnability at 900–1,200 m/min on lightweight coated paper requires a surface sizing or coating binder that remains stable under high-shear conditions in the coating colour. KH-17 is pre-dissolved at 10.0–12.0% solids and then metered into a colour containing kaolin clay 100 parts by dry weight, styrene-butadiene latex 10–12 parts, and KH-17 0.5–2.0 parts as a cobinder. Final coating colour solids are adjusted to 58–62%, with pH 8.5–9.5 and Brookfield RVT viscosity at 1,000–1,900 mPa·s measured with spindle 4 at 100 rpm. The coated sheet is dried at 120–150°C web surface temperature and calendered. Water absorption is monitored by ISO 535:2023 Cobb60. Surface roughness is monitored by ISO 8791-2:2013. Food-contact paperboard using KH-17 falls under FDA 21 CFR 176.170 and 21 CFR 176.180. The final products are printed folding carton stock and thermal paper base. KH-17 must not be used as the sole binder in formulations with calcium carbonate above 20 parts per 100 parts pigment at pH >9.0 because high-shear viscosity loss and watermark formation may occur on the blade. Published data for this specific configuration is limited when all-latex replacement is attempted below 0.5 parts KH-17.

Ceramic Green Tape: Binder Burn-Out Profiles for MLCC and LTCC Substrates

Ceramic green tape formulations containing KH-17 are prepared as non-aqueous slips in a toluene/ethanol or methyl ethyl ketone/ethanol mixture. The ceramic powder, typically 100 parts by weight of barium titanate or glass-ceramic filler, is dispersed with 0.5–1.5 parts phosphate ester dispersant. KH-17 is added at 3.0–8.0 parts by weight as the primary binder. A plasticizer such as polyethylene glycol 400 or dibutyl phthalate is added at 2.0–6.0 parts. The slip is milled or high-shear mixed. The slip is deaerated under vacuum and cast onto a silicone-coated PET carrier at 20–150 µm wet film thickness using a doctor blade. Drying is performed at 25–40°C to avoid skinning. Lamination and punching follow drying. Thermal debinding is carried out at 0.5–1.0°C/min from 200°C to 600°C. A 2 h hold at 450°C and another at 600°C are typical. Residual ash is verified by firing at 850–1,100°C depending on the filler system. Fired substrate density is measured by ISO 18754:2020. KH-17 powder must be pre-dried if ambient relative humidity exceeds 60% because agglomerates cause visible binder lumps in the cast tape. Binder loadings above 8.0 parts by weight increase slurry viscosity beyond 10,000 mPa·s and can produce edge cracking during drying. The final components are multilayer ceramic capacitors and low-temperature co-fired ceramic substrates.

When PVB Resin Precipitation is Controlled by Residual Acetate Content in KH-17

Residual acetate distribution in partially hydrolyzed KH-17 directly influences the acetalization reaction during polyvinyl butyral production. An aqueous KH-17 solution at 8.0–10.0 wt% is prepared and cooled to 10–20°C. Butyraldehyde is metered at a molar ratio of 0.70–0.80 relative to vinyl alcohol units. Hydrochloric acid is added to reduce pH to 0.5–1.5. The reaction is carried out in a baffled glass-lined reactor with a retreat-curve impeller operated at 60–120 rpm. The PVB resin precipitates as discrete particles and is washed to neutral pH. The acetalization degree of the final resin is 70–80 mol%. Residual acetate content is below 3.0 mol%. KH-17 hydrolysis of 78.5–82.5 mol% is preferred where a defined residual acetate content is required to control solubility and plasticizer uptake in the final PVB interlayer. Laminated glass interlayer quality is tested under ISO 12543-2:2021 for mechanical properties. Total acid concentration must not exceed 1.5 mol/L because acid-catalyzed chain scission reduces polyvinyl alcohol molecular weight and leads to low melt strength. The final product is PVB film for automotive laminated glass.

Glass fibre sizing compositions that use KH-17 as the primary film former are prepared at 5.0–10.0% solids in demineralized water. A typical formulation contains 0.5–1.5 parts by weight KH-17 per 100 parts sizing liquor, 0.3–0.8 parts aminosilane coupling agent, 0.1–0.5 parts cationic lubricant, and a weak acid to adjust pH to 4.5–6.5. The fibre is passed over an applicator roll and dried in a forced-air oven at 120–160°C. The final chopped strands are used for polyamide and polybutylene terephthalate reinforcement. Strand integrity is assessed by ISO 3341:2000 for yarn breaking force. Glass content in the compounded polymer is checked by ISO 1172:2023. The PVA film former should not be combined with iron salts above 10 ppm because oxidative crosslinking may cause size pick-up drift. The final product is chopped strand reinforcement for engineering thermoplastics.