CCP PVA BP-10H

The semi-crystalline thermoplastic polyvinyl alcohol resin designated CCP PVA BP-10H is a fully hydrolyzed homopolymer with a nominal degree of hydrolysis of 99.0–99.8 mol% and a 4 % aqueous solution viscosity (at 20 °C, Brookfield LV, spindle #1, 60 rpm) of 10–14 mPa·s. Manufactured via a controlled alcoholysis process that minimizes residual acetyl groups to fewer than 0.2 mol%, this grade exhibits a volatile matter content not exceeding 5.0 wt% (JIS K6726), ash residue of ≤ 0.5 wt%, and a pH in aqueous dispersion of 5.0–7.5. The high stereoregularity imparted by near-complete acetate removal translates into a melting endotherm peak at 228–242 °C (DSC, 10 K/min), a glass transition temperature of approximately 85 °C, and an oxygen transmission rate through a 25 µm cast film at 23 °C and 0 % RH falling below 0.5 cm³/(m²·24 h·atm) when sufficiently plasticized. Unlike partially hydrolyzed co-polymers that dissolve readily in cold water, BP-10H requires a dissolution temperature maintained above 85 °C under vigorous agitation; incomplete solvation below this threshold leads to gel-particle defects in downstream film or coating processes.

What Distinguishes BP-10H from Lower Hydrolysis Grades Such as BP-05 or BP-17?

The functional boundary between partially hydrolyzed polyvinyl alcohols (typically 87–89 mol% for grades like BP-05) and fully hydrolyzed types rests on cold-water dispersibility, crystallinity development, and interfacial adhesion to hydrophobic surfaces. BP-10H carries fewer than 0.2 mol% residual acetate groups; the consequent linear-chain packing yields a crystallinity index (X_c) of 50–55 % by density-gradient column, roughly 20 % higher than BP-05 at 88 mol% hydrolysis. This structural distinction governs practical behavior:

• Solubility: BP-10H remains insoluble in water below 60 °C; BP-05 dissolves at 15–25 °C. This makes BP-10H unsuitable for unit-dose detergent film that must disintegrate in cold wash cycles unless blended with partially hydrolyzed grades or saccharide-based plasticizers.
• Mechanical properties: Tensile strength of BP-10H films conditioned at 50 % RH reaches 75–90 MPa (ASTM D882, 500 mm/min), whereas BP-05 films typically show 45–55 MPa. Elongation at break is conversely lower: 10–20 % for BP-10H versus 200–300 % for BP-05, necessitating plasticizer selection carefully tuned to avoid embrittlement at sub-ambient handling.
• Gas barrier: The higher crystallinity of BP-10H suppresses oxygen permeability by approximately 40 % relative to BP-05 at identical film thickness and plasticizer loading.
• Interlayer adhesion: In PVB interlayer production, acetalization of BP-10H with butyraldehyde proceeds more slowly due to restricted chain mobility but yields final laminate adhesion to glass exceeding 12 N/mm² (pummel test) after controlled moisture equilibration.

Film Extrusion Processing Window and Thermal Stability Limits

Work on cast-film lines with a L/D 30 single-screw extruder, barrier screw, and coat-hanger flat die indicates that a melt temperature range of 210–235 °C is processable without triggering noticeable chain scission when the residence time distribution is limited to 90–120 seconds. At temperatures exceeding 240 °C, acetic acid liberated by thermal elimination of residual acetate (even at <0.2 mol%) autocatalyzes degradation, causing a rapid drop in intrinsic viscosity and an increase in yellowness index (YI D1925) beyond 1.5. Operators running BP-10H on blown-film towers must keep the die gap between 0.8–1.2 mm and employ a frost-line height control that avoids quenching rates faster than 80 °C/s, otherwise micro-voids originating from trapped moisture nucleate and reduce dart impact strength (ASTM D1709, Method A) below 150 g. Pre-drying to a moisture content of ≤ 0.3 wt% (loss-on-drying, 105 °C, 4 h) is mandatory when processing in ambient relative humidity above 60 %. The hygroscopic character of fully hydrolyzed PVA necessitates sealed resin hopper systems with dry-air purge. In co-extrusion with polyolefin tie layers, corona treatment at a surface energy of ≥ 42 mN/m (DIN 53364) on the BP-10H skin enables bonding without delamination during thermal cycling from -20 °C to 80 °C. A frequently encountered failure mode during down-gauging below 15 µm involves transverse-direction tear propagation initiated at gel-particle boundaries; this is mitigated by melt filtration through screens of 100–150 µm gauge and by verifying dissolution completeness via turbidity measurement (NTU ≤ 5 in a 10 % solution at 90 °C).

Property Gradient: CCP PVA Partially vs. Fully Hydrolyzed Grades

Property	Method	BP-05 (87–89 mol%)	BP-10H (99.0–99.8 mol%)	BP-17 (97.5–98.5 mol%)
4 % sol. viscosity	Brookfield LV, 20 °C	4.5–6.0 mPa·s	10–14 mPa·s	25–30 mPa·s
Cold-water solubility	Dissolution at 25 °C	Complete	Insoluble	Partial, cloudy
Tensile strength	ASTM D882 (50 % RH)	45–55 MPa	75–90 MPa	65–80 MPa
Elongation at break	ASTM D882	200–300 %	10–20 %	30–60 %
Oxygen permeability (25 µm, 0 % RH)	ASTM D3985	0.8–1.2 cm³/(m²·d·atm)	<0.5 cm³/(m²·d·atm)	0.6–0.8 cm³/(m²·d·atm)

Adhesion to Polar Substrates and Water Wash-off Resistance In paper-coating formulations designed for high-holdout printability, BP-10H demonstrates a Cobb₆₀ water absorption (ISO 535) value reduced by 35–40 % compared to coatings made with partially hydrolyzed PVA at identical coat weight. The hydroxyl-rich chain segments induce strong hydrogen bonding with cellulosic fibers; nonetheless, surface-bound BP-10H resists removal during offset printing dampening cycles only when the coating has been cured at a web temperature exceeding 180 °C for at least 3 seconds. If the drying section cannot achieve this, a crosslinker such as glyoxal at 0.05–0.2 % on dry weight is required. The same chemistry underpins its use in textile warp sizing where desizing on alkali-scouring ranges needs an oxidative step (hydrogen peroxide at 0.5 %, 80 °C) because single-stage hot water washing leaves residual film on cotton yarns, elevating stiffness by up to 15 %. In applications requiring water-soluble sacrificial layers—such as support structures in ceramic injection moulding—BP-10H is dissolved only after the green body is immersed in circulating water at 85 °C for 2–4 h. The dissolution rate can be accelerated to 0.8 mm/h by introducing 1–3 % methanol into the bath, though methanol quantities above 5 % risk stress-cracking the ceramic binder system. When Partial Replacement of Gelatin in Warp Sizing Yields Cycle Time Reductions In high-speed air-jet weaving where warp yarns are subjected to cyclic bending at 600–850 cycles/min, blends of BP-10H and modified starch at a 30:70 weight ratio reduce size pickup by 1.2–1.5 % absolute versus pure starch while boosting abrasion resistance (measured on a Zweigle abrasion tester) by 40 %. A mill trial on a Tsudakoma ZAX9100 loom processing Ne 40 combed cotton at 750 rpm recorded loom stop frequency dropping from 2.1 to 1.3 stops per hour when the size liquor temperature was maintained at 88–92 °C during application. The technical limitation is that size rebound moisture regain must be kept below 12 %; storage in a shed at> 70 % RH without polyethylene wrapping led to blocking and un-tieable knots on the beam, requiring re-sizing.

Regulatory Compliance Synopsis for CCP PVA BP-10H

Regulation /Standard	Applicable Scope	Status for BP-10H
FDA 21 CFR §175.300	Resinous and polymeric coatings for food contact	Permitted, subject to extraction limits
EU Regulation (EC) No 1935/2004	Materials and articles intended to come into contact with food	Compatible when compounded with listed additives
REACH (EC) 1907/2006	Registration, evaluation, authorisation of chemicals	Weight-of-evidence polymer exemption; full registration not required
RoHS 2011/65/EU (Recast)	Restriction of hazardous substances in electrical equipment	Inherently compliant; does not contain restricted phthalates, heavy metals, or BFRs
JIS K6726:1994	Testing methods for polyvinyl alcohol	Primary specification basis for moisture, ash, pH, viscosity

Corona-treating BP-10H film beyond 42 mN/m wetting tension triggers surface crosslinking detectable as an insoluble gel fraction that complicates gravure printing ink adhesion. Laminators therefore calibrate treaters to a maximum 45 mN/m and verify dyne level within 30 minutes of treatment before the decay curve drops below 40 mN/m. When the film is overlaid with a polyethylene sealant layer immediately after offline treatment, residual active species catalyze interfacial esterification; a waiting interval of 24 h at 35 °C prior to lamination eliminates this anomaly. Plasticizer compatibility deserves explicit attention. Sorbitol and glycerol at loadings of 10–20 phr efficiently lower the glass transition to 15–35 °C without exudation, whereas propylene glycol-based plasticizers induce phase separation after storage under fluctuating humidity. Ethylene carbonate, though effective, must be excluded when the final article must meet EN 71-3 migration limits for toys. Published data for polycondensation plasticizers such as polyester adipates in BP-10H is limited; pilot-scale experiments indicate plasticizer bleed-out at loads above 8 phr when film thickness exceeds 50 µm. The difference between BP-10H and intermediate hydrolysis grades such as BP-17 (97.5–98.5 mol%) becomes critical in emulsion polymerisation stabilisation. Using BP-10H as a protective colloid in vinyl acetate emulsion polymerisation yields a particle size distribution skewed toward 0.8–1.5 µm and viscosity above 5000 mPa·s, while BP-17 under identical reactor conditions (semi-batch, 70 °C, potassium persulfate initiator) produces submicron particles and a final viscosity below 2000 mPa·s. This rheological contrast steers the selection of BP-10H toward high-viscosity wood adhesives meeting DIN EN 204 D3 requirements, where film-forming capacity and heat resistance are valued over pourability.