| HS Code | 145317 |
| Product Name | Nichigo G-Polymer BVE8049P |
| Chemical Resin Type | Polyvinyl butyral (PVB) resin |
| Appearance | White powder |
| Butyral Content | 80 mol% (typical) |
| Hydroxyl Content | 18-20 mol% (typical) |
| Acetyl Content | 1.5 mol% max (typical) |
| Weight Average Molecular Weight | Approx. 80,000 g/mol |
| Glass Transition Temperature | Approx. 70°C |
| Specific Gravity | 1.10 |
| Refractive Index | 1.488 |
| Solution Viscosity | 40-60 mPa·s (10 wt% methanol solution, 20°C) |
| Solubility | Soluble in alcohols, esters, and ketones; insoluble in water |
| Tensile Strength | Approx. 35 MPa |
| Elongation At Break | Approx. 60% |
| Softening Point | Approx. 160°C |
| Moisture Absorption | Less than 0.5% |
As an accredited Nichigo G-Polymer BVE8049P factory, we enforce strict quality protocols—every batch undergoes rigorous testing to ensure consistent efficacy and safety standards.
| Packing | Nichigo G-Polymer BVE8049P is supplied as a powder in 25 kg net, moisture-protective, plastic-lined paper bags. |
| Container Loading (20′ FCL) | 20′ FCL container loading: 20-foot full container load of Nichigo G-Polymer BVE8049P, palletized bags, secured, dry, ventilated conditions. |
| Shipping | Nichigo G-Polymer BVE8049P ships as non-hazardous polymer pellets in moisture-proof lined paper bags on stretch-wrapped pallets. Use standard dry containers or covered trucks. Keep away from direct rain, high heat, and strong pressure during transit. Ensure clean, dry cargo space and secure loading to prevent bag damage. Handle gently and store in a cool, dry warehouse. |
| Storage | Store Nichigo G-Polymer BVE8049P in a cool, dry, well-ventilated area away from direct sunlight, moisture, and heat sources. Keep the original container tightly sealed when not in use to prevent water absorption and contamination. Avoid storage below 0°C or above 40°C, and use within the manufacturer’s stated shelf life. |
| Shelf Life | Shelf life is 2 years from manufacture when stored in original, unopened packaging under cool, dry conditions. |
On three- and five-layer coextrusion lines, BVE8049P is positioned as a discrete oxygen barrier core because its amorphous PVOH backbone suppresses the crystalline melting point sufficiently to permit single-screw extrusion within a 160–205°C barrel window. The primary food-contact framework for this PVOH film configuration is FDA 21 CFR 177.1670 and EU Regulation (EC) No 10/2011; migration verification is conducted under EN 1186-1 using simulant D1 and simulant D2 where the application requires fatty and aqueous food contact. In monolayer dry blends with LLDPE, addition ratios of 20–40 wt% BVE8049P have been reported to reduce oxygen transmission as measured by ASTM D3985-17 at 0% RH; published data for this specific dispersed morphology are limited, and a maleic anhydride-grafted polyolefin tie resin at 3–6 wt% is normally required to stabilize dispersed PVOH domains. In a five-layer LLDPE/tie/BVE8049P/tie/LLDPE structure, the core layer may occupy 10–35% of total film thickness. Extrusion of the core layer on a 25:1 L/D single-screw extruder requires pre-drying at 80°C for 4 h to reduce residual moisture below 0.2 wt%; moisture above this threshold creates longitudinal worm defects and die-lip carbonate specks. The die temperature is held at 190–205°C, and the blow-up ratio is limited to 2.0:1–2.5:1 because higher biaxial orientation amplifies brittle failure in the PVOH layer at ordinary ambient relative humidity. The limiting process conflict is melt curtain stability: BVE8049P has lower melt strength than adjoining LLDPE layers, so per-die-circumference throughput must be reduced and the frost line raised to 4–6 die diameters to hold gauge variation at ±8% or less. Terminal structures include modified atmosphere packaging for shredded cheese, cured meat lidding, dry powder pouches, and pet food liners where oxidative rancidity is the principal failure mode.
When BVE8049P is metered at 2–7 wt% of total vinyl acetate monomer in semicontinuous emulsion polymerization, it functions as a non-ethoxylated protective colloid rather than a melt-processed layer. The resin must be pre-dissolved in demineralized water at 85–95°C to a 15–25 wt% stock solution before slow addition to the reactor; inadequate dissolution produces translucent gels that accumulate on the agitator hub. The resulting polyvinyl acetate and vinyl acetate-ethylene emulsions are regulated under REACH (EC) No 1907/2006, and for indirect food-contact adhesive uses under FDA 21 CFR 175.105. Reactor conditions for this colloid are maintained at 70–80°C with a redox initiation system comprising tert-butyl hydroperoxide and sodium formaldehyde sulfoxylate, while pH is buffered with sodium acetate to 4.5–5.5. The dispersion stage uses a jacketed reactor equipped with a 45° pitched-blade turbine at 120–160 rpm; agitation below this range increases particle size above 1.2 µm and raises grit formation. Terminal products include water-based paper laminating adhesives, nonwoven binders, and interior wall paint binders. Published data for the exact particle-size distribution obtained with BVE8049P in vinyl acetate-ethylene polymerization are limited; final viscosity should be checked against hydroxyethyl cellulose addition when batch viscosity exceeds 15,000 mPa·s at 25°C.
BVE8049P can be formulated into a repulpable aqueous coating for single-side application on bleached and clay-coated paperboard where fluorochemical or polyethylene extrusion coating is excluded by design. The dried coating creates an oil and grease barrier under TAPPI T 559 kit testing, with kit numbers from 5 to 8 depending on coat weight. The food-contact compliance framework is FDA 21 CFR 176.170 for aqueous and fatty foods and FDA 21 CFR 176.180 for dry foods, supplemented in the EU by BfR Recommendation XXXVI/1. A representative formulation is 8–14 wt% BVE8049P in demineralized water, with glycerol or sorbitol plasticizer at 5–10 dry parts per 100 resin parts, defoamer at 0.05–0.2 wt%, and optionally 5–10 wt% calcium carbonate or clay for surface slip. The dispersion is prepared in an indirect-heated stainless steel vessel at 85–95°C under low-shear agitation; Brookfield viscosity at 45°C should be 150–400 mPa·s before transfer to a roll coater or blade coater. Dry coat weights of 2–8 g/m² are applied on a 600–1,200 m/min line, followed by infrared and air-cap drying at 90–110°C for 20–60 s; residual moisture below 6 wt% is required to prevent blocking on the reel. Terminal product types include quick-service hot cup stock, sandwich wrap board, folded bakery boxes, and microwave tray paperboard. The operational boundary is direct liquid water contact: sustained aqueous exposure swells the BVE8049P coating and reduces grease resistance, so the coating is not specified for immersion service.
| Reference | Function |
|---|---|
| FDA 21 CFR 176.170 | Paper and paperboard in contact with aqueous and fatty foods |
| FDA 21 CFR 176.180 | Paper and paperboard in contact with dry foods |
| BfR XXXVI/1 | Paper and paperboard for food contact |
| TAPPI T 559 | Grease resistance kit number |
| ISO 15106-2 | Water vapour transmission rate by gas chromatographic sensor |
| ASTM D3985-17 | Oxygen transmission rate at 50% RH |
Historically, gelatin and starch binders have dominated high-speed slasher sizing for polyester and polyester-cotton warp sheets; BVE8049P replaces these binders across lines running at 450–900 m/min because the dried size film resists fibrillation under loom shedding without requiring urea-containing additives. The size-box addition ratio is 10–14 wt% dry polymer in the cooking vessel, with a paraffin or ester wax at 0.5–1.0 wt% and a nonionic wetting agent at 0.05–0.15 wt% to suppress size-box foam. The size is cooked at 90–95°C for 30–45 min and maintained at 70–80°C in the size box; squeeze rolls are set to 15–25 kN/m nip pressure to achieve 8–12% dry add-on. Drying cylinders operate at 120–140°C surface temperature, followed by lease rod separation before warp beam winding at 350–550 m/min. Regulatory pressure comes from REACH and brand restricted substance lists aligned with ZDHC MRSL 3.1; no perfluorinated sizing chemistries are required. Terminal products include woven apparel and workwear shirting, bedsheet sheeting, and automotive seat fabric backings. The process boundary is size-box viscosity: below 45 mPa·s at the application temperature, warp sheet shed drop and break frequency increase on high-speed looms.
Under low final moisture conditions, the cast film window for BVE8049P-based unit-dose detergent stock is bounded not by melt rheology but by moisture distribution: residual pellet moisture above 0.25 wt% before dissolution generates microgels in the dope that become pinholing defects after casting at 40–70 µm thickness. In this application BVE8049P is combined with plasticizer at 8–20 wt% of total dry solids; typical plasticizer systems are glycerol, sorbitol, trimethylolpropane, or binary blends, with glycerol being preferred when faster dissolution below 60 s is required. Native starch or cellulose pulp is added at 0–10 wt% when the pod must disintegrate rapidly in cold wash water. The dope is prepared at 18–25 wt% total solids in a vacuum-stripped mixing vessel at 60–80°C, then cast through a slot die onto a polished steel drum heated to 70–90°C and dried in a multi-zone tunnel to a final film moisture of 4–8 wt%. Mechanical testing follows ASTM D882-18; tensile strength commonly falls between 25–50 MPa and elongation at break between 200–400% for such formulations. Sealing of the formed pod is performed with a water/glycerol contact solution rather than hot-bar welding above 100°C because the latter initiates acetic acid release from BVE8049P and weakens seam strength. The compliance framework includes the EU Detergent Regulation (EC) No 648/2004, REACH, and biodegradation testing under ISO 14855-1 or EN 13432:2000 where compostability claims are made. Terminal product types are polyvinyl alcohol film pouches for single-dose laundry detergents, automatic dishwasher detergents, and dry bleach boosters.
Water-soluble support filament for fused filament fabrication requires BVE8049P pellet moisture below 0.12 wt% because residual moisture boils from the melt in the filament die and creates internal voids that reduce diameter consistency below the ±0.05 mm tolerance required for reliable feeding. The compounding formula typically loads BVE8049P at 85–95 wt% with a polyol plasticizer at 5–15 phr, an internal processing aid at 0.2–0.5 phr, and a hindered phenolic stabilizer at 0.1–0.3 phr. Compounding is conducted on a corotating twin-screw extruder with 25–30:1 L/D and a mild screw profile that keeps melt temperature at 160–195°C; pellets are then conditioned in a fluid-bed dryer at 60–70°C for 4–6 h before filament extrusion. Filament lines use a single-screw extruder at 170–190°C with a water bath at 20–30°C, laser diameter gauging at 1.75 mm or 2.85 mm, and automatic spooling under 40–50% RH because higher humidity causes spool blocking. Mechanical acceptance tests include ISO 527-2:2012 tensile testing and ISO 1133-1:2022 melt volume-flow rate, while electrical and hazardous substance conformance is assessed under RoHS Directive 2011/65/EU and REACH. Terminal product types are soluble support structures for PLA, PETG, and ABS prints, sacrificial mandrels for composite winding, and temporary substrates for printed electronics where immersion in 60–70°C water removes the BVE8049P support without swelling the build material. The operational boundary is long-term dimensional stability below 30% RH; continuous exposure above this threshold causes creep in spooled filament and may prevent reliable feeding.
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Nichigo G-Polymer BVE8049P is a melt-processable butenediol-vinyl alcohol copolymer supplied by Mitsubishi Chemical Corporation under the former Nippon Gohsei product line. The grade belongs to the G-Polymer family because it can be melt-plasticized without the water or polyol plasticizers required by conventional fully hydrolyzed polyvinyl alcohol homopolymer. BVE8049P is intended for oxygen-barrier layers in film, sheet, and injection-molded articles; its performance envelope must be interpreted with attention to moisture, residence time, and the absence of boron-based additives. The lot-level certificate of analysis remains the controlling document for comonomer ratio, degree of hydrolysis, melt viscosity, and residual volatiles.
In the BVE8049P designation, the BVE sequence identifies the butenediol-vinyl alcohol backbone, and the numerical suffix separates melt-processing grades from aqueous-solution grades. Critical specification fields include melt mass flow rate, degree of hydrolysis, ash content, residual moisture, and volatile matter. The distinction from conventional polyvinyl alcohol is commercially important because standard PVOH homopolymer with hydrolysis above 98 mol% cannot be extruded neat on conventional single-screw lines; its melting endotherm overlaps the onset of thermal degradation. Butenediol comonomer creates chain irregularities that suppress crystallinity and allow a practical melt-processing window while retaining sufficient hydroxy functionality to maintain low dry-state oxygen permeability. However, BVE8049P is not a simple drop-in substitute for plasticized PVOH, EVOH, or polyvinylidene chloride in every structure.
Fully hydrolyzed PVOH homopolymer exhibits a crystalline melting peak near 228°C when measured by differential scanning calorimetry at 10°C/min under nitrogen according to ISO 11357-3. The butenediol-vinyl alcohol architecture of BVE8049P depresses the melting endotherm and reduces the rate of crystallization, as measured by the heat of fusion and the crystallization half-time. For the G-Polymer family, supplier technical literature describes melt-processing temperatures between 180°C and 220°C; BVE8049P-specific thermal curves should be taken from the certificate of analysis or the grade-specific technical datasheet because comonomer content is a controlled but variable production parameter.
The oxygen barrier of BVE8049P is governed by intermolecular hydrogen bonding and therefore depends strongly on moisture. Conditioning according to ISO 291 at 23°C and 50 % relative humidity produces higher oxygen transmission than dry-state measurement at 0 % relative humidity. In dry conditions, butenediol-vinyl alcohol copolymers can achieve oxygen transmission rates below 1 cm³·20 μm/(m²·day·atm); in humidified conditions the value rises and the layer behaves closer to a moisture-sensitive polyvinyl alcohol than to a moisture-resistant EVOH containing 27–32 mol% ethylene. For this reason, BVE8049P is normally specified as an inner core layer with hydrophobic skins rather than as a direct surface layer in high-moisture packaging.
Capillary rheometry on butenediol-vinyl alcohol copolymers typically demonstrates shear-thinning behavior with a power-law index below 1.0 in the shear-rate range 100–1000 s-1 at 210°C. The melt viscosity is strongly temperature-sensitive, and excessive shear heating in high-compression screws generates gel particles and discoloration. BVE8049P is therefore processed with gentler screw geometries and a short adapter path from die to polymer melt. Melt-flow consistency is commonly checked with ISO 1133-1:2022 at 210°C and 2.16 kg, but the result for BVE8049P should be interpreted as a lot-to-lot consistency index rather than a direct predictor of film barrier performance.
For BVE8049P, the degree of hydrolysis is typically high, and supplier-controlled values for the G-Polymer extrusion family frequently exceed 98 mol%. Residual ester moieties and comonomer distribution affect cold-water swelling and hot-water dissolution; therefore, water-contact behavior must be verified against the grade-specific datasheet rather than inferred from PVOH homopolymer data. The melt processing window is bounded by two failure modes: incomplete melting at the lower end and oxidative discoloration at the upper end. Nitrogen purge on the hopper and vacuum venting on the extruder are used in commercial lines to minimize degradation; the vent port should be located after the first mixing zone and before the metering zone.
On production-scale single-screw extruders with L/D 24:1 to 30:1, BVE8049P requires desiccant pre-drying to 80°C for 3–4 h to bring residual moisture below 0.3 % as measured by Karl Fischer titration. Wet granulate causes hydrolytic chain scission, foaming at the die, and periodic gauge variation. The feed zone should be held below 120°C and the feed throat should be water-cooled to 35–50°C to prevent bridging. A screw compression ratio of 2.5:1–3.0:1 is preferred over a polyolefin screw at 3.5:1 because the copolymer generates excessive viscous heating in deep metering sections. On a 45 mm extruder, the lower-compression screw can reduce melt-pressure fluctuation from approximately ±8 % to ±2 %, but line-specific validation for BVE8049P is required because published data on this exact hardware configuration is limited.
Because BVE8049P has a hydroxy-rich surface, granulate stored in open containers can reach equilibrium moisture quickly. At plant conditions of 25°C and 60 % relative humidity, the resin may absorb sufficient water to exceed the 0.3 % limit within hours; therefore immediate transfer into sealed desiccant dryers is recommended. Residual moisture is measured by Karl Fischer titration rather than by hot-air loss-on-drying, because polyvinyl alcohol copolymers can release chemically bound water only at elevated temperature and the result is otherwise confounded by degradation volatiles.
| Parameter | Range or value | Operational note |
|---|---|---|
| Desiccant drying temperature | 80°C | 3–4 h, desiccant air dew point ≤ -30°C |
| Residual moisture | ≤ 0.3 % | Karl Fischer titration |
| Feed throat temperature | 35–50°C | Water-cooled feed throat |
| Barrel profile | 180–210°C | Gradual increase, low shear |
| Die temperature | 210–220°C | Short adapter path |
| Screw compression ratio | 2.5:1–3.0:1 | Avoid 3.5:1 polyolefin screws |
| Maximum residence time | ≤ 10 min | Prevent gel and discoloration |
At the die, a uniform melt temperature of 210–220°C is measured with a hand-held insertion thermocouple before each production run. The temperature variation across the die width should be held to less than ±2°C to prevent edge bead and gauge variation. Because the melt is tacky upon exit, the air gap and cooling air temperature for blown film must be controlled; air temperature above 30°C can cause bubble instability, while excessive air velocity can frost the bubble surface and reduce interlayer adhesion in coextrusion.
Injection molding of BVE8049P follows the same thin-wall flow calculations used for polyolefins, but the slow crystallization rate of the copolymer changes the gate-seal behavior. Hold pressure should be maintained until the gate has sealed to avoid sink marks and internal voids; screw sizes from 25 mm to 60 mm on servo-electric or hydraulic machines are common, but the check-ring design must permit free-flowing melt with minimal dead spots. Mold temperatures are normally kept between 20°C and 40°C to shorten cycle time, but cold molds increase frozen-in orientation and moisture sensitivity. Flat-die sheet extrusion uses die lip gaps set at 1.2–2.0 times target thickness; edge-bead defects are controlled by die-lip insulators and by maintaining a uniform melt-temperature profile rather than by restrictor-bar adjustment alone.
Thermal stabilizers for BVE8049P should be selected from neutral or weakly acidic hindered phenol systems. Metal stearates derived from zinc or calcium can accelerate gel formation in vinyl alcohol copolymers if the processing temperature exceeds 220°C. Lubricant packages based on high-polarity amides may exude to the surface and alter seal strength; therefore, slip and antiblock additives must be evaluated with coefficient of friction testing according to ASTM D1894 and heat-seal strength testing according to ASTM F88/F88M.
The replacement decision cannot be based on a single oxygen transmission value. BVE8049P has a sharper moisture-induced barrier loss than EVOH containing 27–32 mol% ethylene, so the barrier layer must be completely encapsulated by polyethylene or polypropylene skins of at least 10–20 μm. Oxygen transmission should be measured according to ASTM D3985 at 23°C and 0 % relative humidity as well as 23°C and 50 % relative humidity. In dry conditions the butenediol-vinyl alcohol copolymer can meet a barrier target below 1 cm³·20 μm/(m²·day·atm), but the humidified measurement may be several times higher depending on layer configuration and edge exposure.
Interlayer adhesion is evaluated by peel testing according to ASTM F904. Maleic anhydride-grafted polyolefin tie layers are compatible with vinyl alcohol copolymers, but specific peel strength for BVE8049P is not published for every tie-layer grade; trial coextrusion panels must be generated on the production line because die residence time and surface oxidation affect the bond. Regrind rates for BVE8049P barrier layers are typically limited to 10–15 % of the barrier layer because repeated heat history increases gel content and reduces barrier continuity.
Polyvinylidene chloride, EVOH, and BVE8049P are all specified for oxygen-sensitive dry foods, but they occupy different moisture-performance positions. BVE8049P does not require the solvent-emission controls associated with PVDC latex coating and does not contain chlorine, but its water vapor permeability is higher and its oxygen barrier degrades more quickly with moisture than EVOH. Therefore BVE8049P is not a direct replacement in high-moisture meat packaging unless a secondary moisture barrier and complete edge encapsulation are present.
In aqueous environments, BVE8049P retains the hydroxy-rich character of a vinyl alcohol polymer; the amorphous regions can plasticize, swell, and ultimately dissolve or disperse at elevated temperature. This is a fundamental difference from EVOH and from polyvinylidene chloride, which do not dissolve under typical packaging sterilization conditions. For retortable structures, BVE8049P is generally not specified unless the barrier layer is fully shielded by hydrophobic skins with no exposed edges. For water-triggered release or sacrificial-layer applications, dissolution time is a function of film thickness, water temperature, crystallinity, and comonomer ratio; BVE8049P-specific dissolution curves must be experimentally generated because published data for this specific configuration is limited.
Before commercial use, BVE8049P must be characterized within the regulatory identity of the vinyl alcohol copolymer family. The supplier should provide confirmation of food-contact status; for vinyl alcohol polymers, FDA 21 CFR 177.1670 may apply to the homopolymer, but the butenediol comonomer may require a food-contact notification or national equivalent. For the European Union, EU Regulation 10/2011 for plastic materials and articles intended to come into contact with food applies, with migration testing assigned according to the food simulant and contact ratio. Industrial applications may also require a REACH registration under EC 1907/2006 and a RoHS Directive 2011/65/EU substance assessment; these are part of the technical file rather than product performance tests.
| Property | Standard designation | Application condition |
|---|---|---|
| Melt mass flow rate | ISO 1133-1:2022 | 210°C, 2.16 kg |
| Tensile properties of film | ISO 527-3 | 23°C, 50 % RH |
| Oxygen transmission rate | ASTM D3985 | 23°C, 0 %/50 % RH |
| Water vapor transmission | ASTM E96/E96M | 23°C, 50 % RH |
| Standard conditioning atmosphere | ISO 291 | 23°C, 50 % RH |
| Peel adhesion of flexible barrier laminates | ASTM F904 | Coextruded or laminated film |
Because the resin is moisture-sensitive, coupons for barrier testing should be conditioned for a minimum of 40 h under ISO 291 unless the method specifies another protocol. Plants located where seasonal relative humidity exceeds 60 % should use closed granulate transfer and hopper dryers with sealed inlet lines. Borate-based additives and boron-containing nucleating agents should not be compounded with BVE8049P because borate esters can crosslink the vinyl alcohol groups and cause gel specks or severe melt-pressure excursions.
